freebsd-skq/sys/net/route.c

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
1994-05-24 10:09:53 +00:00
* Copyright (c) 1980, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
1994-05-24 10:09:53 +00:00
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)route.c 8.3.1.1 (Berkeley) 2/23/95
1999-08-28 01:08:13 +00:00
* $FreeBSD$
1994-05-24 10:09:53 +00:00
*/
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
/************************************************************************
* Note: In this file a 'fib' is a "forwarding information base" *
* Which is the new name for an in kernel routing (next hop) table. *
***********************************************************************/
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#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_mrouting.h"
#include "opt_route.h"
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#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
1994-05-24 10:09:53 +00:00
#include <sys/mbuf.h>
#include <sys/socket.h>
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
#include <sys/sysctl.h>
#include <sys/syslog.h>
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
#include <sys/sysproto.h>
#include <sys/proc.h>
1994-05-24 10:09:53 +00:00
#include <sys/domain.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
1994-05-24 10:09:53 +00:00
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
1994-05-24 10:09:53 +00:00
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/route_var.h>
Introduce nexthop objects and new routing KPI. This is the foundational change for the routing subsytem rearchitecture. More details and goals are available in https://reviews.freebsd.org/D24141 . This patch introduces concept of nexthop objects and new nexthop-based routing KPI. Nexthops are objects, containing all necessary information for performing the packet output decision. Output interface, mtu, flags, gw address goes there. For most of the cases, these objects will serve the same role as the struct rtentry is currently serving. Typically there will be low tens of such objects for the router even with multiple BGP full-views, as these objects will be shared between routing entries. This allows to store more information in the nexthop. New KPI: struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, uint32_t flowid); struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, uint32_t flowid); These 2 function are intended to replace all all flavours of <in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous fib[46]-generation functions. Upon successful lookup, they return nexthop object which is guaranteed to exist within current NET_EPOCH. If longer lifetime is desired, one can specify NHR_REF as a flag and get a referenced version of the nexthop. Reference semantic closely resembles rtentry one, allowing sed-style conversion. Additionally, another 2 functions are introduced to support uRPF functionality inside variety of our firewalls. Their primary goal is to hide the multipath implementation details inside the routing subsystem, greatly simplifying firewalls implementation: int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); All functions have a separate scopeid argument, paving way to eliminating IPv6 scope embedding and allowing to support IPv4 link-locals in the future. Structure changes: * rtentry gets new 'rt_nhop' pointer, slightly growing the overall size. * rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz. Old KPI: During the transition state old and new KPI will coexists. As there are another 4-5 decent-sized conversion patches, it will probably take a couple of weeks. To support both KPIs, fields not required by the new KPI (most of rtentry) has to be kept, resulting in the temporary size increase. Once conversion is finished, rtentry will notably shrink. More details: * architectural overview: https://reviews.freebsd.org/D24141 * list of the next changes: https://reviews.freebsd.org/D24232 Reviewed by: ae,glebius(initial version) Differential Revision: https://reviews.freebsd.org/D24232
2020-04-12 14:30:00 +00:00
#include <net/route/nhop.h>
#include <net/vnet.h>
1994-05-24 10:09:53 +00:00
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
1994-05-24 10:09:53 +00:00
#include <netinet/in.h>
#include <netinet/ip_mroute.h>
1994-05-24 10:09:53 +00:00
Introduce nexthop objects and new routing KPI. This is the foundational change for the routing subsytem rearchitecture. More details and goals are available in https://reviews.freebsd.org/D24141 . This patch introduces concept of nexthop objects and new nexthop-based routing KPI. Nexthops are objects, containing all necessary information for performing the packet output decision. Output interface, mtu, flags, gw address goes there. For most of the cases, these objects will serve the same role as the struct rtentry is currently serving. Typically there will be low tens of such objects for the router even with multiple BGP full-views, as these objects will be shared between routing entries. This allows to store more information in the nexthop. New KPI: struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, uint32_t flowid); struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, uint32_t flowid); These 2 function are intended to replace all all flavours of <in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous fib[46]-generation functions. Upon successful lookup, they return nexthop object which is guaranteed to exist within current NET_EPOCH. If longer lifetime is desired, one can specify NHR_REF as a flag and get a referenced version of the nexthop. Reference semantic closely resembles rtentry one, allowing sed-style conversion. Additionally, another 2 functions are introduced to support uRPF functionality inside variety of our firewalls. Their primary goal is to hide the multipath implementation details inside the routing subsystem, greatly simplifying firewalls implementation: int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); All functions have a separate scopeid argument, paving way to eliminating IPv6 scope embedding and allowing to support IPv4 link-locals in the future. Structure changes: * rtentry gets new 'rt_nhop' pointer, slightly growing the overall size. * rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz. Old KPI: During the transition state old and new KPI will coexists. As there are another 4-5 decent-sized conversion patches, it will probably take a couple of weeks. To support both KPIs, fields not required by the new KPI (most of rtentry) has to be kept, resulting in the temporary size increase. Once conversion is finished, rtentry will notably shrink. More details: * architectural overview: https://reviews.freebsd.org/D24141 * list of the next changes: https://reviews.freebsd.org/D24232 Reviewed by: ae,glebius(initial version) Differential Revision: https://reviews.freebsd.org/D24232
2020-04-12 14:30:00 +00:00
VNET_PCPUSTAT_DEFINE(struct rtstat, rtstat);
VNET_PCPUSTAT_SYSINIT(rtstat);
#ifdef VIMAGE
VNET_PCPUSTAT_SYSUNINIT(rtstat);
#endif
EVENTHANDLER_LIST_DEFINE(rt_addrmsg);
static int rt_ifdelroute(const struct rtentry *rt, const struct nhop_object *,
void *arg);
static int rt_exportinfo(struct rtentry *rt, struct rt_addrinfo *info,
int flags);
/*
* route initialization must occur before ip6_init2(), which happenas at
* SI_ORDER_MIDDLE.
*/
2004-04-17 15:10:20 +00:00
static void
route_init(void)
1994-05-24 10:09:53 +00:00
{
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
Introduce nexthop objects and new routing KPI. This is the foundational change for the routing subsytem rearchitecture. More details and goals are available in https://reviews.freebsd.org/D24141 . This patch introduces concept of nexthop objects and new nexthop-based routing KPI. Nexthops are objects, containing all necessary information for performing the packet output decision. Output interface, mtu, flags, gw address goes there. For most of the cases, these objects will serve the same role as the struct rtentry is currently serving. Typically there will be low tens of such objects for the router even with multiple BGP full-views, as these objects will be shared between routing entries. This allows to store more information in the nexthop. New KPI: struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, uint32_t flowid); struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, uint32_t flowid); These 2 function are intended to replace all all flavours of <in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous fib[46]-generation functions. Upon successful lookup, they return nexthop object which is guaranteed to exist within current NET_EPOCH. If longer lifetime is desired, one can specify NHR_REF as a flag and get a referenced version of the nexthop. Reference semantic closely resembles rtentry one, allowing sed-style conversion. Additionally, another 2 functions are introduced to support uRPF functionality inside variety of our firewalls. Their primary goal is to hide the multipath implementation details inside the routing subsystem, greatly simplifying firewalls implementation: int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); All functions have a separate scopeid argument, paving way to eliminating IPv6 scope embedding and allowing to support IPv4 link-locals in the future. Structure changes: * rtentry gets new 'rt_nhop' pointer, slightly growing the overall size. * rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz. Old KPI: During the transition state old and new KPI will coexists. As there are another 4-5 decent-sized conversion patches, it will probably take a couple of weeks. To support both KPIs, fields not required by the new KPI (most of rtentry) has to be kept, resulting in the temporary size increase. Once conversion is finished, rtentry will notably shrink. More details: * architectural overview: https://reviews.freebsd.org/D24141 * list of the next changes: https://reviews.freebsd.org/D24232 Reviewed by: ae,glebius(initial version) Differential Revision: https://reviews.freebsd.org/D24232
2020-04-12 14:30:00 +00:00
nhops_init();
}
SYSINIT(route_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, route_init, NULL);
struct rib_head *
rt_table_init(int offset, int family, u_int fibnum)
{
struct rib_head *rh;
rh = malloc(sizeof(struct rib_head), M_RTABLE, M_WAITOK | M_ZERO);
/* TODO: These details should be hidded inside radix.c */
/* Init masks tree */
rn_inithead_internal(&rh->head, rh->rnh_nodes, offset);
rn_inithead_internal(&rh->rmhead.head, rh->rmhead.mask_nodes, 0);
rh->head.rnh_masks = &rh->rmhead;
/* Save metadata associated with this routing table. */
rh->rib_family = family;
rh->rib_fibnum = fibnum;
#ifdef VIMAGE
rh->rib_vnet = curvnet;
#endif
tmproutes_init(rh);
/* Init locks */
RIB_LOCK_INIT(rh);
Introduce nexthop objects and new routing KPI. This is the foundational change for the routing subsytem rearchitecture. More details and goals are available in https://reviews.freebsd.org/D24141 . This patch introduces concept of nexthop objects and new nexthop-based routing KPI. Nexthops are objects, containing all necessary information for performing the packet output decision. Output interface, mtu, flags, gw address goes there. For most of the cases, these objects will serve the same role as the struct rtentry is currently serving. Typically there will be low tens of such objects for the router even with multiple BGP full-views, as these objects will be shared between routing entries. This allows to store more information in the nexthop. New KPI: struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, uint32_t flowid); struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, uint32_t flowid); These 2 function are intended to replace all all flavours of <in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous fib[46]-generation functions. Upon successful lookup, they return nexthop object which is guaranteed to exist within current NET_EPOCH. If longer lifetime is desired, one can specify NHR_REF as a flag and get a referenced version of the nexthop. Reference semantic closely resembles rtentry one, allowing sed-style conversion. Additionally, another 2 functions are introduced to support uRPF functionality inside variety of our firewalls. Their primary goal is to hide the multipath implementation details inside the routing subsystem, greatly simplifying firewalls implementation: int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); All functions have a separate scopeid argument, paving way to eliminating IPv6 scope embedding and allowing to support IPv4 link-locals in the future. Structure changes: * rtentry gets new 'rt_nhop' pointer, slightly growing the overall size. * rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz. Old KPI: During the transition state old and new KPI will coexists. As there are another 4-5 decent-sized conversion patches, it will probably take a couple of weeks. To support both KPIs, fields not required by the new KPI (most of rtentry) has to be kept, resulting in the temporary size increase. Once conversion is finished, rtentry will notably shrink. More details: * architectural overview: https://reviews.freebsd.org/D24141 * list of the next changes: https://reviews.freebsd.org/D24232 Reviewed by: ae,glebius(initial version) Differential Revision: https://reviews.freebsd.org/D24232
2020-04-12 14:30:00 +00:00
nhops_init_rib(rh);
/* Init subscription system */
rib_init_subscriptions(rh);
/* Finally, set base callbacks */
rh->rnh_addaddr = rn_addroute;
rh->rnh_deladdr = rn_delete;
rh->rnh_matchaddr = rn_match;
rh->rnh_lookup = rn_lookup;
rh->rnh_walktree = rn_walktree;
rh->rnh_walktree_from = rn_walktree_from;
return (rh);
}
static int
rt_freeentry(struct radix_node *rn, void *arg)
{
struct radix_head * const rnh = arg;
struct radix_node *x;
x = (struct radix_node *)rn_delete(rn + 2, NULL, rnh);
if (x != NULL)
R_Free(x);
return (0);
}
void
rt_table_destroy(struct rib_head *rh)
{
tmproutes_destroy(rh);
rn_walktree(&rh->rmhead.head, rt_freeentry, &rh->rmhead.head);
Introduce nexthop objects and new routing KPI. This is the foundational change for the routing subsytem rearchitecture. More details and goals are available in https://reviews.freebsd.org/D24141 . This patch introduces concept of nexthop objects and new nexthop-based routing KPI. Nexthops are objects, containing all necessary information for performing the packet output decision. Output interface, mtu, flags, gw address goes there. For most of the cases, these objects will serve the same role as the struct rtentry is currently serving. Typically there will be low tens of such objects for the router even with multiple BGP full-views, as these objects will be shared between routing entries. This allows to store more information in the nexthop. New KPI: struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, uint32_t flowid); struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, uint32_t flowid); These 2 function are intended to replace all all flavours of <in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous fib[46]-generation functions. Upon successful lookup, they return nexthop object which is guaranteed to exist within current NET_EPOCH. If longer lifetime is desired, one can specify NHR_REF as a flag and get a referenced version of the nexthop. Reference semantic closely resembles rtentry one, allowing sed-style conversion. Additionally, another 2 functions are introduced to support uRPF functionality inside variety of our firewalls. Their primary goal is to hide the multipath implementation details inside the routing subsystem, greatly simplifying firewalls implementation: int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); All functions have a separate scopeid argument, paving way to eliminating IPv6 scope embedding and allowing to support IPv4 link-locals in the future. Structure changes: * rtentry gets new 'rt_nhop' pointer, slightly growing the overall size. * rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz. Old KPI: During the transition state old and new KPI will coexists. As there are another 4-5 decent-sized conversion patches, it will probably take a couple of weeks. To support both KPIs, fields not required by the new KPI (most of rtentry) has to be kept, resulting in the temporary size increase. Once conversion is finished, rtentry will notably shrink. More details: * architectural overview: https://reviews.freebsd.org/D24141 * list of the next changes: https://reviews.freebsd.org/D24232 Reviewed by: ae,glebius(initial version) Differential Revision: https://reviews.freebsd.org/D24232
2020-04-12 14:30:00 +00:00
nhops_destroy_rib(rh);
rib_destroy_subscriptions(rh);
/* Assume table is already empty */
RIB_LOCK_DESTROY(rh);
free(rh, M_RTABLE);
}
1994-05-24 10:09:53 +00:00
/*
* Adds a temporal redirect entry to the routing table.
* @fibnum: fib number
* @dst: destination to install redirect to
* @gateway: gateway to go via
* @author: sockaddr of originating router, can be NULL
* @ifp: interface to use for the redirected route
* @flags: set of flags to add. Allowed: RTF_GATEWAY
* @lifetime_sec: time in seconds to expire this redirect.
*
* Retuns 0 on success, errno otherwise.
1994-05-24 10:09:53 +00:00
*/
int
rib_add_redirect(u_int fibnum, struct sockaddr *dst, struct sockaddr *gateway,
struct sockaddr *author, struct ifnet *ifp, int flags, int lifetime_sec)
1994-05-24 10:09:53 +00:00
{
struct rib_cmd_info rc;
int error;
1994-05-24 10:09:53 +00:00
struct rt_addrinfo info;
struct rt_metrics rti_rmx;
1994-05-24 10:09:53 +00:00
struct ifaddr *ifa;
Widen NET_EPOCH coverage. When epoch(9) was introduced to network stack, it was basically dropped in place of existing locking, which was mutexes and rwlocks. For the sake of performance mutex covered areas were as small as possible, so became epoch covered areas. However, epoch doesn't introduce any contention, it just delays memory reclaim. So, there is no point to minimise epoch covered areas in sense of performance. Meanwhile entering/exiting epoch also has non-zero CPU usage, so doing this less often is a win. Not the least is also code maintainability. In the new paradigm we can assume that at any stage of processing a packet, we are inside network epoch. This makes coding both input and output path way easier. On output path we already enter epoch quite early - in the ip_output(), in the ip6_output(). This patch does the same for the input path. All ISR processing, network related callouts, other ways of packet injection to the network stack shall be performed in net_epoch. Any leaf function that walks network configuration now asserts epoch. Tricky part is configuration code paths - ioctls, sysctls. They also call into leaf functions, so some need to be changed. This patch would introduce more epoch recursions (see EPOCH_TRACE) than we had before. They will be cleaned up separately, as several of them aren't trivial. Note, that unlike a lock recursion the epoch recursion is safe and just wastes a bit of resources. Reviewed by: gallatin, hselasky, cy, adrian, kristof Differential Revision: https://reviews.freebsd.org/D19111
2019-10-07 22:40:05 +00:00
NET_EPOCH_ASSERT();
if (rt_tables_get_rnh(fibnum, dst->sa_family) == NULL)
return (EAFNOSUPPORT);
/* Verify the allowed flag mask. */
KASSERT(((flags & ~(RTF_GATEWAY)) == 0),
("invalid redirect flags: %x", flags));
flags |= RTF_HOST | RTF_DYNAMIC;
/* Get the best ifa for the given interface and gateway. */
if ((ifa = ifaof_ifpforaddr(gateway, ifp)) == NULL)
return (ENETUNREACH);
ifa_ref(ifa);
bzero(&info, sizeof(info));
info.rti_info[RTAX_DST] = dst;
info.rti_info[RTAX_GATEWAY] = gateway;
info.rti_ifa = ifa;
info.rti_ifp = ifp;
info.rti_flags = flags;
/* Setup route metrics to define expire time. */
bzero(&rti_rmx, sizeof(rti_rmx));
/* Set expire time as absolute. */
rti_rmx.rmx_expire = lifetime_sec + time_second;
info.rti_mflags |= RTV_EXPIRE;
info.rti_rmx = &rti_rmx;
error = rib_action(fibnum, RTM_ADD, &info, &rc);
ifa_free(ifa);
if (error != 0) {
/* TODO: add per-fib redirect stats. */
return (error);
}
RTSTAT_INC(rts_dynamic);
/* Send notification of a route addition to userland. */
bzero(&info, sizeof(info));
1994-05-24 10:09:53 +00:00
info.rti_info[RTAX_DST] = dst;
info.rti_info[RTAX_GATEWAY] = gateway;
info.rti_info[RTAX_AUTHOR] = author;
rt_missmsg_fib(RTM_REDIRECT, &info, flags | RTF_UP, error, fibnum);
return (0);
1994-05-24 10:09:53 +00:00
}
/*
2002-12-18 11:46:59 +00:00
* Routing table ioctl interface.
*/
1994-05-24 10:09:53 +00:00
int
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
rtioctl_fib(u_long req, caddr_t data, u_int fibnum)
1994-05-24 10:09:53 +00:00
{
/*
* If more ioctl commands are added here, make sure the proper
* super-user checks are being performed because it is possible for
* prison-root to make it this far if raw sockets have been enabled
* in jails.
*/
#ifdef INET
Initial get-the-easy-case-working upgrade of the multicast code to something more recent than the ancient 1.2 release contained in 4.4. This code has the following advantages as compared to previous versions (culled from the README file for the SunOS release): - True multicast delivery - Configurable rate-limiting of forwarded multicast traffic on each physical interface or tunnel, using a token-bucket limiter. - Simplistic classification of packets for prioritized dropping. - Administrative scoping of multicast address ranges. - Faster detection of hosts leaving groups. - Support for multicast traceroute (code not yet available). - Support for RSVP, the Resource Reservation Protocol. What still needs to be done: - The multicast forwarder needs testing. - The multicast routing daemon needs to be ported. - Network interface drivers need to have the `#ifdef MULTICAST' goop ripped out of them. - The IGMP code should probably be bogon-tested. Some notes about the porting process: In some cases, the Berkeley people decided to incorporate functionality from later releases of the multicast code, but then had to do things differently. As a result, if you look at Deering's patches, and then look at our code, it is not always obvious whether the patch even applies. Let the reader beware. I ran ip_mroute.c through several passes of `unifdef' to get rid of useless grot, and to permanently enable the RSVP support, which we will include as standard. Ported by: Garrett Wollman Submitted by: Steve Deering and Ajit Thyagarajan (among others)
1994-09-06 22:42:31 +00:00
/* Multicast goop, grrr... */
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
return mrt_ioctl ? mrt_ioctl(req, data, fibnum) : EOPNOTSUPP;
#else /* INET */
return ENXIO;
#endif /* INET */
1994-05-24 10:09:53 +00:00
}
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
struct ifaddr *
ifa_ifwithroute(int flags, const struct sockaddr *dst,
const struct sockaddr *gateway, u_int fibnum)
1994-05-24 10:09:53 +00:00
{
struct ifaddr *ifa;
NET_EPOCH_ASSERT();
1994-05-24 10:09:53 +00:00
if ((flags & RTF_GATEWAY) == 0) {
/*
* If we are adding a route to an interface,
* and the interface is a pt to pt link
* we should search for the destination
* as our clue to the interface. Otherwise
* we can use the local address.
*/
ifa = NULL;
if (flags & RTF_HOST)
ifa = ifa_ifwithdstaddr(dst, fibnum);
if (ifa == NULL)
1994-05-24 10:09:53 +00:00
ifa = ifa_ifwithaddr(gateway);
} else {
/*
* If we are adding a route to a remote net
* or host, the gateway may still be on the
* other end of a pt to pt link.
*/
ifa = ifa_ifwithdstaddr(gateway, fibnum);
1994-05-24 10:09:53 +00:00
}
if (ifa == NULL)
ifa = ifa_ifwithnet(gateway, 0, fibnum);
if (ifa == NULL) {
struct nhop_object *nh;
nh = rib_lookup(fibnum, gateway, NHR_NONE, 0);
/*
* dismiss a gateway that is reachable only
* through the default router
*/
if ((nh == NULL) || (nh->nh_flags & NHF_DEFAULT))
return (NULL);
ifa = nh->nh_ifa;
1994-05-24 10:09:53 +00:00
}
if (ifa->ifa_addr->sa_family != dst->sa_family) {
struct ifaddr *oifa = ifa;
ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
if (ifa == NULL)
1994-05-24 10:09:53 +00:00
ifa = oifa;
}
1994-05-24 10:09:53 +00:00
return (ifa);
}
/*
* Copy most of @rt data into @info.
*
* If @flags contains NHR_COPY, copies dst,netmask and gw to the
* pointers specified by @info structure. Assume such pointers
* are zeroed sockaddr-like structures with sa_len field initialized
* to reflect size of the provided buffer. if no NHR_COPY is specified,
* point dst,netmask and gw @info fields to appropriate @rt values.
*
* if @flags contains NHR_REF, do refcouting on rt_ifp and rt_ifa.
*
* Returns 0 on success.
*/
int
rt_exportinfo(struct rtentry *rt, struct rt_addrinfo *info, int flags)
{
struct rt_metrics *rmx;
struct sockaddr *src, *dst;
Convert rtentry field accesses into nhop field accesses. One of the goals of the new routing KPI defined in r359823 is to entirely hide`struct rtentry` from the consumers. It will allow to improve routing subsystem internals and deliver more features much faster. This commit is mostly mechanical change to eliminate direct struct rtentry field accesses. The only notable difference is AF_LINK gateway encoding. AF_LINK gw is used in routing stack for operations with interface routes and host loopback routes. In the former case it indicates _some_ non-NULL gateway, as the interface is the same as in rt_ifp in kernel and rtm_ifindex in rtsock reporting. In the latter case the interface index inside gateway was used by the IPv6 datapath to verify address scope for link-local interfaces. Kernel uses struct sockaddr_dl for this type of gateway. This structure allows for specifying rich interface data, such as mac address and interface name. However, this results in relatively large structure size - 52 bytes. Routing stack fils in only 2 fields - sdl_index and sdl_type, which reside in the first 8 bytes of the structure. In the new KPI, struct nhop_object tries to be cache-efficient, hence embodies gateway address inside the structure. In the AF_LINK case it stores stortened version of the structure - struct sockaddr_dl_short, which occupies 16 bytes. After D24340 changes, the data inside AF_LINK gateway will not be used in the kernel at all, leaving rtsock as the only potential concern. The difference in rtsock reporting: (old) got message of size 240 on Thu Apr 16 03:12:13 2020 RTM_ADD: Add Route: len 240, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 (new) got message of size 200 on Sun Apr 19 09:46:32 2020 RTM_ADD: Add Route: len 200, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 Note 40 bytes different (52-16 + alignment). However, gateway is still a valid AF_LINK gateway with proper data filled in. It is worth noting that these particular messages (interface routes) are mostly ignored by routing daemons: * bird/quagga/frr uses RTM_NEWADDR and ignores prefix route addition messages. * quagga/frr ignores routes without gateway More detailed overview on how rtsock messages are used by the routing daemons to reconstruct the kernel view, can be found in D22974. Differential Revision: https://reviews.freebsd.org/D24519
2020-04-23 08:04:20 +00:00
struct nhop_object *nh;
int sa_len;
nh = rt->rt_nhop;
if (flags & NHR_COPY) {
/* Copy destination if dst is non-zero */
src = rt_key(rt);
dst = info->rti_info[RTAX_DST];
sa_len = src->sa_len;
if (dst != NULL) {
if (src->sa_len > dst->sa_len)
return (ENOMEM);
memcpy(dst, src, src->sa_len);
info->rti_addrs |= RTA_DST;
}
/* Copy mask if set && dst is non-zero */
src = rt_mask(rt);
dst = info->rti_info[RTAX_NETMASK];
if (src != NULL && dst != NULL) {
/*
* Radix stores different value in sa_len,
* assume rt_mask() to have the same length
* as rt_key()
*/
if (sa_len > dst->sa_len)
return (ENOMEM);
memcpy(dst, src, src->sa_len);
info->rti_addrs |= RTA_NETMASK;
}
/* Copy gateway is set && dst is non-zero */
src = &nh->gw_sa;
dst = info->rti_info[RTAX_GATEWAY];
if ((nhop_get_rtflags(nh) & RTF_GATEWAY) &&
src != NULL && dst != NULL) {
if (src->sa_len > dst->sa_len)
return (ENOMEM);
memcpy(dst, src, src->sa_len);
info->rti_addrs |= RTA_GATEWAY;
}
} else {
info->rti_info[RTAX_DST] = rt_key(rt);
info->rti_addrs |= RTA_DST;
if (rt_mask(rt) != NULL) {
info->rti_info[RTAX_NETMASK] = rt_mask(rt);
info->rti_addrs |= RTA_NETMASK;
}
if (nhop_get_rtflags(nh) & RTF_GATEWAY) {
info->rti_info[RTAX_GATEWAY] = &nh->gw_sa;
info->rti_addrs |= RTA_GATEWAY;
}
}
rmx = info->rti_rmx;
if (rmx != NULL) {
info->rti_mflags |= RTV_MTU;
Convert rtentry field accesses into nhop field accesses. One of the goals of the new routing KPI defined in r359823 is to entirely hide`struct rtentry` from the consumers. It will allow to improve routing subsystem internals and deliver more features much faster. This commit is mostly mechanical change to eliminate direct struct rtentry field accesses. The only notable difference is AF_LINK gateway encoding. AF_LINK gw is used in routing stack for operations with interface routes and host loopback routes. In the former case it indicates _some_ non-NULL gateway, as the interface is the same as in rt_ifp in kernel and rtm_ifindex in rtsock reporting. In the latter case the interface index inside gateway was used by the IPv6 datapath to verify address scope for link-local interfaces. Kernel uses struct sockaddr_dl for this type of gateway. This structure allows for specifying rich interface data, such as mac address and interface name. However, this results in relatively large structure size - 52 bytes. Routing stack fils in only 2 fields - sdl_index and sdl_type, which reside in the first 8 bytes of the structure. In the new KPI, struct nhop_object tries to be cache-efficient, hence embodies gateway address inside the structure. In the AF_LINK case it stores stortened version of the structure - struct sockaddr_dl_short, which occupies 16 bytes. After D24340 changes, the data inside AF_LINK gateway will not be used in the kernel at all, leaving rtsock as the only potential concern. The difference in rtsock reporting: (old) got message of size 240 on Thu Apr 16 03:12:13 2020 RTM_ADD: Add Route: len 240, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 (new) got message of size 200 on Sun Apr 19 09:46:32 2020 RTM_ADD: Add Route: len 200, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 Note 40 bytes different (52-16 + alignment). However, gateway is still a valid AF_LINK gateway with proper data filled in. It is worth noting that these particular messages (interface routes) are mostly ignored by routing daemons: * bird/quagga/frr uses RTM_NEWADDR and ignores prefix route addition messages. * quagga/frr ignores routes without gateway More detailed overview on how rtsock messages are used by the routing daemons to reconstruct the kernel view, can be found in D22974. Differential Revision: https://reviews.freebsd.org/D24519
2020-04-23 08:04:20 +00:00
rmx->rmx_mtu = nh->nh_mtu;
}
info->rti_flags = rt->rte_flags | nhop_get_rtflags(nh);
Convert rtentry field accesses into nhop field accesses. One of the goals of the new routing KPI defined in r359823 is to entirely hide`struct rtentry` from the consumers. It will allow to improve routing subsystem internals and deliver more features much faster. This commit is mostly mechanical change to eliminate direct struct rtentry field accesses. The only notable difference is AF_LINK gateway encoding. AF_LINK gw is used in routing stack for operations with interface routes and host loopback routes. In the former case it indicates _some_ non-NULL gateway, as the interface is the same as in rt_ifp in kernel and rtm_ifindex in rtsock reporting. In the latter case the interface index inside gateway was used by the IPv6 datapath to verify address scope for link-local interfaces. Kernel uses struct sockaddr_dl for this type of gateway. This structure allows for specifying rich interface data, such as mac address and interface name. However, this results in relatively large structure size - 52 bytes. Routing stack fils in only 2 fields - sdl_index and sdl_type, which reside in the first 8 bytes of the structure. In the new KPI, struct nhop_object tries to be cache-efficient, hence embodies gateway address inside the structure. In the AF_LINK case it stores stortened version of the structure - struct sockaddr_dl_short, which occupies 16 bytes. After D24340 changes, the data inside AF_LINK gateway will not be used in the kernel at all, leaving rtsock as the only potential concern. The difference in rtsock reporting: (old) got message of size 240 on Thu Apr 16 03:12:13 2020 RTM_ADD: Add Route: len 240, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 (new) got message of size 200 on Sun Apr 19 09:46:32 2020 RTM_ADD: Add Route: len 200, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 Note 40 bytes different (52-16 + alignment). However, gateway is still a valid AF_LINK gateway with proper data filled in. It is worth noting that these particular messages (interface routes) are mostly ignored by routing daemons: * bird/quagga/frr uses RTM_NEWADDR and ignores prefix route addition messages. * quagga/frr ignores routes without gateway More detailed overview on how rtsock messages are used by the routing daemons to reconstruct the kernel view, can be found in D22974. Differential Revision: https://reviews.freebsd.org/D24519
2020-04-23 08:04:20 +00:00
info->rti_ifp = nh->nh_ifp;
info->rti_ifa = nh->nh_ifa;
if (flags & NHR_REF) {
if_ref(info->rti_ifp);
ifa_ref(info->rti_ifa);
}
return (0);
}
/*
* Lookups up route entry for @dst in RIB database for fib @fibnum.
* Exports entry data to @info using rt_exportinfo().
*
* If @flags contains NHR_REF, refcouting is performed on rt_ifp and rt_ifa.
* All references can be released later by calling rib_free_info().
*
* Returns 0 on success.
* Returns ENOENT for lookup failure, ENOMEM for export failure.
*/
int
rib_lookup_info(uint32_t fibnum, const struct sockaddr *dst, uint32_t flags,
uint32_t flowid, struct rt_addrinfo *info)
{
RIB_RLOCK_TRACKER;
struct rib_head *rh;
struct radix_node *rn;
struct rtentry *rt;
int error;
KASSERT((fibnum < rt_numfibs), ("rib_lookup_rte: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, dst->sa_family);
if (rh == NULL)
return (ENOENT);
RIB_RLOCK(rh);
rn = rh->rnh_matchaddr(__DECONST(void *, dst), &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rt = RNTORT(rn);
/* Ensure route & ifp is UP */
if (RT_LINK_IS_UP(rt->rt_nhop->nh_ifp)) {
flags = (flags & NHR_REF) | NHR_COPY;
error = rt_exportinfo(rt, info, flags);
RIB_RUNLOCK(rh);
return (error);
}
}
RIB_RUNLOCK(rh);
return (ENOENT);
}
/*
* Releases all references acquired by rib_lookup_info() when
* called with NHR_REF flags.
*/
void
rib_free_info(struct rt_addrinfo *info)
{
ifa_free(info->rti_ifa);
if_rele(info->rti_ifp);
}
/*
* Iterates over all existing fibs in system calling
* @setwa_f function prior to traversing each fib.
* Calls @wa_f function for each element in current fib.
* If af is not AF_UNSPEC, iterates over fibs in particular
* address family.
*/
void
rt_foreach_fib_walk(int af, rt_setwarg_t *setwa_f, rt_walktree_f_t *wa_f,
void *arg)
{
struct rib_head *rnh;
uint32_t fibnum;
int i;
for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
/* Do we want some specific family? */
if (af != AF_UNSPEC) {
rnh = rt_tables_get_rnh(fibnum, af);
if (rnh == NULL)
continue;
if (setwa_f != NULL)
setwa_f(rnh, fibnum, af, arg);
RIB_WLOCK(rnh);
rnh->rnh_walktree(&rnh->head, (walktree_f_t *)wa_f,arg);
RIB_WUNLOCK(rnh);
continue;
}
for (i = 1; i <= AF_MAX; i++) {
rnh = rt_tables_get_rnh(fibnum, i);
if (rnh == NULL)
continue;
if (setwa_f != NULL)
setwa_f(rnh, fibnum, i, arg);
RIB_WLOCK(rnh);
rnh->rnh_walktree(&rnh->head, (walktree_f_t *)wa_f,arg);
RIB_WUNLOCK(rnh);
}
}
}
/*
* Iterates over all existing fibs in system and deletes each element
* for which @filter_f function returns non-zero value.
* If @family is not AF_UNSPEC, iterates over fibs in particular
* address family.
*/
void
rt_foreach_fib_walk_del(int family, rt_filter_f_t *filter_f, void *arg)
{
u_int fibnum;
int i, start, end;
for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
/* Do we want some specific family? */
if (family != AF_UNSPEC) {
start = family;
end = family;
} else {
start = 1;
end = AF_MAX;
}
for (i = start; i <= end; i++) {
if (rt_tables_get_rnh(fibnum, i) == NULL)
continue;
rib_walk_del(fibnum, i, filter_f, arg, 0);
}
}
}
/*
* Delete Routes for a Network Interface
*
* Called for each routing entry via the rnh->rnh_walktree() call above
* to delete all route entries referencing a detaching network interface.
*
* Arguments:
* rt pointer to rtentry
* nh pointer to nhop
* arg argument passed to rnh->rnh_walktree() - detaching interface
*
* Returns:
* 0 successful
* errno failed - reason indicated
*/
static int
rt_ifdelroute(const struct rtentry *rt, const struct nhop_object *nh, void *arg)
{
struct ifnet *ifp = arg;
if (nh->nh_ifp != ifp)
return (0);
/*
* Protect (sorta) against walktree recursion problems
* with cloned routes
*/
if ((rt->rte_flags & RTF_UP) == 0)
return (0);
return (1);
}
/*
* Delete all remaining routes using this interface
* Unfortuneatly the only way to do this is to slog through
* the entire routing table looking for routes which point
* to this interface...oh well...
*/
void
rt_flushifroutes_af(struct ifnet *ifp, int af)
{
KASSERT((af >= 1 && af <= AF_MAX), ("%s: af %d not >= 1 and <= %d",
__func__, af, AF_MAX));
rt_foreach_fib_walk_del(af, rt_ifdelroute, ifp);
}
void
rt_flushifroutes(struct ifnet *ifp)
{
rt_foreach_fib_walk_del(AF_UNSPEC, rt_ifdelroute, ifp);
}
/*
* Look up rt_addrinfo for a specific fib. Note that if rti_ifa is defined,
* it will be referenced so the caller must free it.
*
* Assume basic consistency checks are executed by callers:
* RTAX_DST exists, if RTF_GATEWAY is set, RTAX_GATEWAY exists as well.
*/
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
int
rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum)
{
const struct sockaddr *dst, *gateway, *ifpaddr, *ifaaddr;
struct epoch_tracker et;
int needref, error, flags;
dst = info->rti_info[RTAX_DST];
gateway = info->rti_info[RTAX_GATEWAY];
ifpaddr = info->rti_info[RTAX_IFP];
ifaaddr = info->rti_info[RTAX_IFA];
flags = info->rti_flags;
/*
* ifp may be specified by sockaddr_dl
* when protocol address is ambiguous.
*/
error = 0;
needref = (info->rti_ifa == NULL);
NET_EPOCH_ENTER(et);
/* If we have interface specified by the ifindex in the address, use it */
if (info->rti_ifp == NULL && ifpaddr != NULL &&
ifpaddr->sa_family == AF_LINK) {
const struct sockaddr_dl *sdl = (const struct sockaddr_dl *)ifpaddr;
if (sdl->sdl_index != 0)
info->rti_ifp = ifnet_byindex(sdl->sdl_index);
}
/*
* If we have source address specified, try to find it
* TODO: avoid enumerating all ifas on all interfaces.
*/
if (info->rti_ifa == NULL && ifaaddr != NULL)
info->rti_ifa = ifa_ifwithaddr(ifaaddr);
if (info->rti_ifa == NULL) {
const struct sockaddr *sa;
/*
* Most common use case for the userland-supplied routes.
*
* Choose sockaddr to select ifa.
* -- if ifp is set --
* Order of preference:
* 1) IFA address
* 2) gateway address
* Note: for interface routes link-level gateway address
* is specified to indicate the interface index without
* specifying RTF_GATEWAY. In this case, ignore gateway
* Note: gateway AF may be different from dst AF. In this case,
* ignore gateway
* 3) final destination.
* 4) if all of these fails, try to get at least link-level ifa.
* -- else --
* try to lookup gateway or dst in the routing table to get ifa
*/
if (info->rti_info[RTAX_IFA] != NULL)
sa = info->rti_info[RTAX_IFA];
else if ((info->rti_flags & RTF_GATEWAY) != 0 &&
gateway->sa_family == dst->sa_family)
sa = gateway;
else
sa = dst;
if (info->rti_ifp != NULL) {
info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp);
/* Case 4 */
if (info->rti_ifa == NULL && gateway != NULL)
info->rti_ifa = ifaof_ifpforaddr(gateway, info->rti_ifp);
} else if (dst != NULL && gateway != NULL)
info->rti_ifa = ifa_ifwithroute(flags, dst, gateway,
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
fibnum);
else if (sa != NULL)
info->rti_ifa = ifa_ifwithroute(flags, sa, sa,
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
fibnum);
}
if (needref && info->rti_ifa != NULL) {
if (info->rti_ifp == NULL)
info->rti_ifp = info->rti_ifa->ifa_ifp;
ifa_ref(info->rti_ifa);
} else
error = ENETUNREACH;
NET_EPOCH_EXIT(et);
return (error);
}
void
rt_updatemtu(struct ifnet *ifp)
{
struct rib_head *rnh;
int mtu;
int i, j;
/*
* Try to update rt_mtu for all routes using this interface
* Unfortunately the only way to do this is to traverse all
* routing tables in all fibs/domains.
*/
for (i = 1; i <= AF_MAX; i++) {
mtu = if_getmtu_family(ifp, i);
for (j = 0; j < rt_numfibs; j++) {
rnh = rt_tables_get_rnh(j, i);
if (rnh == NULL)
continue;
nhops_update_ifmtu(rnh, ifp, mtu);
}
}
}
#if 0
int p_sockaddr(char *buf, int buflen, struct sockaddr *s);
int rt_print(char *buf, int buflen, struct rtentry *rt);
int
p_sockaddr(char *buf, int buflen, struct sockaddr *s)
{
void *paddr = NULL;
switch (s->sa_family) {
case AF_INET:
paddr = &((struct sockaddr_in *)s)->sin_addr;
break;
case AF_INET6:
paddr = &((struct sockaddr_in6 *)s)->sin6_addr;
break;
}
if (paddr == NULL)
return (0);
if (inet_ntop(s->sa_family, paddr, buf, buflen) == NULL)
return (0);
return (strlen(buf));
}
int
rt_print(char *buf, int buflen, struct rtentry *rt)
{
struct sockaddr *addr, *mask;
int i = 0;
addr = rt_key(rt);
mask = rt_mask(rt);
i = p_sockaddr(buf, buflen, addr);
if (!(rt->rt_flags & RTF_HOST)) {
buf[i++] = '/';
i += p_sockaddr(buf + i, buflen - i, mask);
}
if (rt->rt_flags & RTF_GATEWAY) {
buf[i++] = '>';
Convert rtentry field accesses into nhop field accesses. One of the goals of the new routing KPI defined in r359823 is to entirely hide`struct rtentry` from the consumers. It will allow to improve routing subsystem internals and deliver more features much faster. This commit is mostly mechanical change to eliminate direct struct rtentry field accesses. The only notable difference is AF_LINK gateway encoding. AF_LINK gw is used in routing stack for operations with interface routes and host loopback routes. In the former case it indicates _some_ non-NULL gateway, as the interface is the same as in rt_ifp in kernel and rtm_ifindex in rtsock reporting. In the latter case the interface index inside gateway was used by the IPv6 datapath to verify address scope for link-local interfaces. Kernel uses struct sockaddr_dl for this type of gateway. This structure allows for specifying rich interface data, such as mac address and interface name. However, this results in relatively large structure size - 52 bytes. Routing stack fils in only 2 fields - sdl_index and sdl_type, which reside in the first 8 bytes of the structure. In the new KPI, struct nhop_object tries to be cache-efficient, hence embodies gateway address inside the structure. In the AF_LINK case it stores stortened version of the structure - struct sockaddr_dl_short, which occupies 16 bytes. After D24340 changes, the data inside AF_LINK gateway will not be used in the kernel at all, leaving rtsock as the only potential concern. The difference in rtsock reporting: (old) got message of size 240 on Thu Apr 16 03:12:13 2020 RTM_ADD: Add Route: len 240, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 (new) got message of size 200 on Sun Apr 19 09:46:32 2020 RTM_ADD: Add Route: len 200, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 Note 40 bytes different (52-16 + alignment). However, gateway is still a valid AF_LINK gateway with proper data filled in. It is worth noting that these particular messages (interface routes) are mostly ignored by routing daemons: * bird/quagga/frr uses RTM_NEWADDR and ignores prefix route addition messages. * quagga/frr ignores routes without gateway More detailed overview on how rtsock messages are used by the routing daemons to reconstruct the kernel view, can be found in D22974. Differential Revision: https://reviews.freebsd.org/D24519
2020-04-23 08:04:20 +00:00
i += p_sockaddr(buf + i, buflen - i, &rt->rt_nhop->gw_sa);
}
return (i);
}
#endif
#ifdef RADIX_MPATH
/*
* Deletes key for single-path routes, unlinks rtentry with
* gateway specified in @info from multi-path routes.
*
* Returnes unlinked entry. In case of failure, returns NULL
* and sets @perror to ESRCH.
*/
struct radix_node *
rt_mpath_unlink(struct rib_head *rnh, struct rt_addrinfo *info,
struct rtentry *rto, int *perror)
{
/*
* if we got multipath routes, we require users to specify
* a matching RTAX_GATEWAY.
*/
struct rtentry *rt; // *rto = NULL;
struct radix_node *rn;
struct sockaddr *gw;
gw = info->rti_info[RTAX_GATEWAY];
rt = rt_mpath_matchgate(rto, gw);
if (rt == NULL) {
*perror = ESRCH;
return (NULL);
}
/*
* this is the first entry in the chain
*/
if (rto == rt) {
rn = rn_mpath_next((struct radix_node *)rt);
/*
* there is another entry, now it's active
*/
if (rn) {
rto = RNTORT(rn);
rto->rte_flags |= RTF_UP;
} else if (rt->rte_flags & RTF_GATEWAY) {
/*
* For gateway routes, we need to
* make sure that we we are deleting
* the correct gateway.
* rt_mpath_matchgate() does not
* check the case when there is only
* one route in the chain.
*/
if (gw &&
Convert rtentry field accesses into nhop field accesses. One of the goals of the new routing KPI defined in r359823 is to entirely hide`struct rtentry` from the consumers. It will allow to improve routing subsystem internals and deliver more features much faster. This commit is mostly mechanical change to eliminate direct struct rtentry field accesses. The only notable difference is AF_LINK gateway encoding. AF_LINK gw is used in routing stack for operations with interface routes and host loopback routes. In the former case it indicates _some_ non-NULL gateway, as the interface is the same as in rt_ifp in kernel and rtm_ifindex in rtsock reporting. In the latter case the interface index inside gateway was used by the IPv6 datapath to verify address scope for link-local interfaces. Kernel uses struct sockaddr_dl for this type of gateway. This structure allows for specifying rich interface data, such as mac address and interface name. However, this results in relatively large structure size - 52 bytes. Routing stack fils in only 2 fields - sdl_index and sdl_type, which reside in the first 8 bytes of the structure. In the new KPI, struct nhop_object tries to be cache-efficient, hence embodies gateway address inside the structure. In the AF_LINK case it stores stortened version of the structure - struct sockaddr_dl_short, which occupies 16 bytes. After D24340 changes, the data inside AF_LINK gateway will not be used in the kernel at all, leaving rtsock as the only potential concern. The difference in rtsock reporting: (old) got message of size 240 on Thu Apr 16 03:12:13 2020 RTM_ADD: Add Route: len 240, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 (new) got message of size 200 on Sun Apr 19 09:46:32 2020 RTM_ADD: Add Route: len 200, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 link#5 255.255.255.0 Note 40 bytes different (52-16 + alignment). However, gateway is still a valid AF_LINK gateway with proper data filled in. It is worth noting that these particular messages (interface routes) are mostly ignored by routing daemons: * bird/quagga/frr uses RTM_NEWADDR and ignores prefix route addition messages. * quagga/frr ignores routes without gateway More detailed overview on how rtsock messages are used by the routing daemons to reconstruct the kernel view, can be found in D22974. Differential Revision: https://reviews.freebsd.org/D24519
2020-04-23 08:04:20 +00:00
(rt->rt_nhop->gw_sa.sa_len != gw->sa_len ||
memcmp(&rt->rt_nhop->gw_sa, gw, gw->sa_len))) {
*perror = ESRCH;
return (NULL);
}
}
/*
* use the normal delete code to remove
* the first entry
*/
rn = rnh->rnh_deladdr(info->rti_info[RTAX_DST],
info->rti_info[RTAX_NETMASK],
&rnh->head);
if (rn != NULL) {
*perror = 0;
} else {
*perror = ESRCH;
}
return (rn);
}
/*
* if the entry is 2nd and on up
*/
if (rt_mpath_deldup(rto, rt) == 0)
panic ("rtrequest1: rt_mpath_deldup");
*perror = 0;
rn = (struct radix_node *)rt;
return (rn);
}
#endif
void
rt_maskedcopy(struct sockaddr *src, struct sockaddr *dst, struct sockaddr *netmask)
1994-05-24 10:09:53 +00:00
{
u_char *cp1 = (u_char *)src;
u_char *cp2 = (u_char *)dst;
u_char *cp3 = (u_char *)netmask;
1994-05-24 10:09:53 +00:00
u_char *cplim = cp2 + *cp3;
u_char *cplim2 = cp2 + *cp1;
*cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */
cp3 += 2;
if (cplim > cplim2)
cplim = cplim2;
while (cp2 < cplim)
*cp2++ = *cp1++ & *cp3++;
if (cp2 < cplim2)
bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2));
}
/*
* Announce interface address arrival/withdraw
* Returns 0 on success.
*/
int
rt_addrmsg(int cmd, struct ifaddr *ifa, int fibnum)
{
KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE,
Simplify inet alias handling code: if we're adding/removing alias which has the same prefix as some other alias on the same interface, use newly-added rt_addrmsg() instead of hand-rolled in_addralias_rtmsg(). This eliminates the following rtsock messages: Pinned RTM_ADD for prefix (for alias addition). Pinned RTM_DELETE for prefix (for alias withdrawal). Example (got 10.0.0.1/24 on vlan4, playing with 10.0.0.2/24): before commit, addition: got message of size 116 on Fri Jan 10 14:13:15 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 got message of size 192 on Fri Jan 10 14:13:15 2014 RTM_ADD: Add Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff after commit, addition: got message of size 116 on Fri Jan 10 13:56:26 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 14.0.0.2 14.0.0.255 before commit, wihdrawal: got message of size 192 on Fri Jan 10 13:58:59 2014 RTM_DELETE: Delete Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff got message of size 116 on Fri Jan 10 13:58:59 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 adter commit, withdrawal: got message of size 116 on Fri Jan 10 14:14:11 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 Sending both RTM_ADD/RTM_DELETE messages to rtsock is completely wrong (and requires some hacks to keep prefix in route table on RTM_DELETE). I've tested this change with quagga (no change) and bird (*). bird alias handling is already broken in *BSD sysdep code, so nothing changes here, too. I'm going to MFC this change if there will be no complains about behavior change. While here, fix some style(9) bugs introduced by r260488 (pointed by glebius and bde). Sponsored by: Yandex LLC MFC after: 4 weeks
2014-01-10 12:13:55 +00:00
("unexpected cmd %d", cmd));
KASSERT(fibnum == RT_ALL_FIBS || (fibnum >= 0 && fibnum < rt_numfibs),
("%s: fib out of range 0 <=%d<%d", __func__, fibnum, rt_numfibs));
EVENTHANDLER_DIRECT_INVOKE(rt_addrmsg, ifa, cmd);
return (rtsock_addrmsg(cmd, ifa, fibnum));
}
/*
* Announce kernel-originated route addition/removal to rtsock based on @rt data.
* cmd: RTM_ cmd
* @rt: valid rtentry
* @ifp: target route interface
* @fibnum: fib id or RT_ALL_FIBS
*
* Returns 0 on success.
*/
int
rt_routemsg(int cmd, struct rtentry *rt, struct ifnet *ifp, int rti_addrs,
int fibnum)
{
KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE,
Simplify inet alias handling code: if we're adding/removing alias which has the same prefix as some other alias on the same interface, use newly-added rt_addrmsg() instead of hand-rolled in_addralias_rtmsg(). This eliminates the following rtsock messages: Pinned RTM_ADD for prefix (for alias addition). Pinned RTM_DELETE for prefix (for alias withdrawal). Example (got 10.0.0.1/24 on vlan4, playing with 10.0.0.2/24): before commit, addition: got message of size 116 on Fri Jan 10 14:13:15 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 got message of size 192 on Fri Jan 10 14:13:15 2014 RTM_ADD: Add Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff after commit, addition: got message of size 116 on Fri Jan 10 13:56:26 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 14.0.0.2 14.0.0.255 before commit, wihdrawal: got message of size 192 on Fri Jan 10 13:58:59 2014 RTM_DELETE: Delete Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff got message of size 116 on Fri Jan 10 13:58:59 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 adter commit, withdrawal: got message of size 116 on Fri Jan 10 14:14:11 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 Sending both RTM_ADD/RTM_DELETE messages to rtsock is completely wrong (and requires some hacks to keep prefix in route table on RTM_DELETE). I've tested this change with quagga (no change) and bird (*). bird alias handling is already broken in *BSD sysdep code, so nothing changes here, too. I'm going to MFC this change if there will be no complains about behavior change. While here, fix some style(9) bugs introduced by r260488 (pointed by glebius and bde). Sponsored by: Yandex LLC MFC after: 4 weeks
2014-01-10 12:13:55 +00:00
("unexpected cmd %d", cmd));
Simplify inet alias handling code: if we're adding/removing alias which has the same prefix as some other alias on the same interface, use newly-added rt_addrmsg() instead of hand-rolled in_addralias_rtmsg(). This eliminates the following rtsock messages: Pinned RTM_ADD for prefix (for alias addition). Pinned RTM_DELETE for prefix (for alias withdrawal). Example (got 10.0.0.1/24 on vlan4, playing with 10.0.0.2/24): before commit, addition: got message of size 116 on Fri Jan 10 14:13:15 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 got message of size 192 on Fri Jan 10 14:13:15 2014 RTM_ADD: Add Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff after commit, addition: got message of size 116 on Fri Jan 10 13:56:26 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 14.0.0.2 14.0.0.255 before commit, wihdrawal: got message of size 192 on Fri Jan 10 13:58:59 2014 RTM_DELETE: Delete Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff got message of size 116 on Fri Jan 10 13:58:59 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 adter commit, withdrawal: got message of size 116 on Fri Jan 10 14:14:11 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 Sending both RTM_ADD/RTM_DELETE messages to rtsock is completely wrong (and requires some hacks to keep prefix in route table on RTM_DELETE). I've tested this change with quagga (no change) and bird (*). bird alias handling is already broken in *BSD sysdep code, so nothing changes here, too. I'm going to MFC this change if there will be no complains about behavior change. While here, fix some style(9) bugs introduced by r260488 (pointed by glebius and bde). Sponsored by: Yandex LLC MFC after: 4 weeks
2014-01-10 12:13:55 +00:00
KASSERT(fibnum == RT_ALL_FIBS || (fibnum >= 0 && fibnum < rt_numfibs),
("%s: fib out of range 0 <=%d<%d", __func__, fibnum, rt_numfibs));
KASSERT(rt_key(rt) != NULL, (":%s: rt_key must be supplied", __func__));
return (rtsock_routemsg(cmd, rt, ifp, 0, fibnum));
}
/*
* Announce kernel-originated route addition/removal to rtsock based on @rt data.
* cmd: RTM_ cmd
* @info: addrinfo structure with valid data.
* @fibnum: fib id or RT_ALL_FIBS
*
* Returns 0 on success.
*/
int
rt_routemsg_info(int cmd, struct rt_addrinfo *info, int fibnum)
{
KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE || cmd == RTM_CHANGE,
("unexpected cmd %d", cmd));
KASSERT(fibnum == RT_ALL_FIBS || (fibnum >= 0 && fibnum < rt_numfibs),
("%s: fib out of range 0 <=%d<%d", __func__, fibnum, rt_numfibs));
KASSERT(info->rti_info[RTAX_DST] != NULL, (":%s: RTAX_DST must be supplied", __func__));
return (rtsock_routemsg_info(cmd, info, fibnum));
}
/*
* This is called to generate messages from the routing socket
* indicating a network interface has had addresses associated with it.
*/
void
rt_newaddrmsg_fib(int cmd, struct ifaddr *ifa, struct rtentry *rt, int fibnum)
{
KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE,
("unexpected cmd %u", cmd));
Simplify inet alias handling code: if we're adding/removing alias which has the same prefix as some other alias on the same interface, use newly-added rt_addrmsg() instead of hand-rolled in_addralias_rtmsg(). This eliminates the following rtsock messages: Pinned RTM_ADD for prefix (for alias addition). Pinned RTM_DELETE for prefix (for alias withdrawal). Example (got 10.0.0.1/24 on vlan4, playing with 10.0.0.2/24): before commit, addition: got message of size 116 on Fri Jan 10 14:13:15 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 got message of size 192 on Fri Jan 10 14:13:15 2014 RTM_ADD: Add Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff after commit, addition: got message of size 116 on Fri Jan 10 13:56:26 2014 RTM_NEWADDR: address being added to iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 14.0.0.2 14.0.0.255 before commit, wihdrawal: got message of size 192 on Fri Jan 10 13:58:59 2014 RTM_DELETE: Delete Route: len 192, pid: 0, seq 0, errno 0, flags:<UP,PINNED> locks: inits: sockaddrs: <DST,GATEWAY,NETMASK> 10.0.0.0 10.0.0.2 (255) ffff ffff ff got message of size 116 on Fri Jan 10 13:58:59 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 adter commit, withdrawal: got message of size 116 on Fri Jan 10 14:14:11 2014 RTM_DELADDR: address being removed from iface: len 116, metric 0, flags: sockaddrs: <NETMASK,IFP,IFA,BRD> 255.255.255.0 vlan4:8.0.27.c5.29.d4 10.0.0.2 10.0.0.255 Sending both RTM_ADD/RTM_DELETE messages to rtsock is completely wrong (and requires some hacks to keep prefix in route table on RTM_DELETE). I've tested this change with quagga (no change) and bird (*). bird alias handling is already broken in *BSD sysdep code, so nothing changes here, too. I'm going to MFC this change if there will be no complains about behavior change. While here, fix some style(9) bugs introduced by r260488 (pointed by glebius and bde). Sponsored by: Yandex LLC MFC after: 4 weeks
2014-01-10 12:13:55 +00:00
KASSERT(fibnum == RT_ALL_FIBS || (fibnum >= 0 && fibnum < rt_numfibs),
("%s: fib out of range 0 <=%d<%d", __func__, fibnum, rt_numfibs));
if (cmd == RTM_ADD) {
rt_addrmsg(cmd, ifa, fibnum);
if (rt != NULL)
rt_routemsg(cmd, rt, ifa->ifa_ifp, 0, fibnum);
} else {
if (rt != NULL)
rt_routemsg(cmd, rt, ifa->ifa_ifp, 0, fibnum);
rt_addrmsg(cmd, ifa, fibnum);
}
}