freebsd-dev/sys/net/if_gif.c

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* Copyright (c) 2018 Andrey V. Elsukov <ae@FreeBSD.org>
* 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 project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
*
* $KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
2004-05-30 20:27:19 +00:00
#include <sys/module.h>
#include <sys/rmlock.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sx.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/priv.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/proc.h>
#include <sys/conf.h>
#include <machine/cpu.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_clone.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/bpf.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_ecn.h>
#ifdef INET
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#endif /* INET */
#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_ecn.h>
#include <netinet6/ip6_var.h>
#endif /* INET6 */
#include <netinet/ip_encap.h>
#include <net/ethernet.h>
#include <net/if_bridgevar.h>
#include <net/if_gif.h>
#include <security/mac/mac_framework.h>
static const char gifname[] = "gif";
MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
static struct sx gif_ioctl_sx;
SX_SYSINIT(gif_ioctl_sx, &gif_ioctl_sx, "gif_ioctl");
Conditionally compile out V_ globals while instantiating the appropriate container structures, depending on VIMAGE_GLOBALS compile time option. Make VIMAGE_GLOBALS a new compile-time option, which by default will not be defined, resulting in instatiations of global variables selected for V_irtualization (enclosed in #ifdef VIMAGE_GLOBALS blocks) to be effectively compiled out. Instantiate new global container structures to hold V_irtualized variables: vnet_net_0, vnet_inet_0, vnet_inet6_0, vnet_ipsec_0, vnet_netgraph_0, and vnet_gif_0. Update the VSYM() macro so that depending on VIMAGE_GLOBALS the V_ macros resolve either to the original globals, or to fields inside container structures, i.e. effectively #ifdef VIMAGE_GLOBALS #define V_rt_tables rt_tables #else #define V_rt_tables vnet_net_0._rt_tables #endif Update SYSCTL_V_*() macros to operate either on globals or on fields inside container structs. Extend the internal kldsym() lookups with the ability to resolve selected fields inside the virtualization container structs. This applies only to the fields which are explicitly registered for kldsym() visibility via VNET_MOD_DECLARE() and vnet_mod_register(), currently this is done only in sys/net/if.c. Fix a few broken instances of MODULE_GLOBAL() macro use in SCTP code, and modify the MODULE_GLOBAL() macro to resolve to V_ macros, which in turn result in proper code being generated depending on VIMAGE_GLOBALS. De-virtualize local static variables in sys/contrib/pf/net/pf_subr.c which were prematurely V_irtualized by automated V_ prepending scripts during earlier merging steps. PF virtualization will be done separately, most probably after next PF import. Convert a few variable initializations at instantiation to initialization in init functions, most notably in ipfw. Also convert TUNABLE_INT() initializers for V_ variables to TUNABLE_FETCH_INT() in initializer functions. Discussed at: devsummit Strassburg Reviewed by: bz, julian Approved by: julian (mentor) Obtained from: //depot/projects/vimage-commit2/... X-MFC after: never Sponsored by: NLnet Foundation, The FreeBSD Foundation
2008-12-10 23:12:39 +00:00
2001-09-26 23:50:17 +00:00
void (*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af);
void (*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
void (*ng_gif_attach_p)(struct ifnet *ifp);
void (*ng_gif_detach_p)(struct ifnet *ifp);
#ifdef VIMAGE
static void gif_reassign(struct ifnet *, struct vnet *, char *);
#endif
static void gif_delete_tunnel(struct gif_softc *);
static int gif_ioctl(struct ifnet *, u_long, caddr_t);
static int gif_transmit(struct ifnet *, struct mbuf *);
static void gif_qflush(struct ifnet *);
static int gif_clone_create(struct if_clone *, int, caddr_t);
static void gif_clone_destroy(struct ifnet *);
VNET_DEFINE_STATIC(struct if_clone *, gif_cloner);
#define V_gif_cloner VNET(gif_cloner)
SYSCTL_DECL(_net_link);
static SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Generic Tunnel Interface");
#ifndef MAX_GIF_NEST
/*
* This macro controls the default upper limitation on nesting of gif tunnels.
* Since, setting a large value to this macro with a careless configuration
* may introduce system crash, we don't allow any nestings by default.
* If you need to configure nested gif tunnels, you can define this macro
* in your kernel configuration file. However, if you do so, please be
* careful to configure the tunnels so that it won't make a loop.
*/
#define MAX_GIF_NEST 1
#endif
VNET_DEFINE_STATIC(int, max_gif_nesting) = MAX_GIF_NEST;
#define V_max_gif_nesting VNET(max_gif_nesting)
SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_VNET | CTLFLAG_RW,
Build on Jeff Roberson's linker-set based dynamic per-CPU allocator (DPCPU), as suggested by Peter Wemm, and implement a new per-virtual network stack memory allocator. Modify vnet to use the allocator instead of monolithic global container structures (vinet, ...). This change solves many binary compatibility problems associated with VIMAGE, and restores ELF symbols for virtualized global variables. Each virtualized global variable exists as a "reference copy", and also once per virtual network stack. Virtualized global variables are tagged at compile-time, placing the in a special linker set, which is loaded into a contiguous region of kernel memory. Virtualized global variables in the base kernel are linked as normal, but those in modules are copied and relocated to a reserved portion of the kernel's vnet region with the help of a the kernel linker. Virtualized global variables exist in per-vnet memory set up when the network stack instance is created, and are initialized statically from the reference copy. Run-time access occurs via an accessor macro, which converts from the current vnet and requested symbol to a per-vnet address. When "options VIMAGE" is not compiled into the kernel, normal global ELF symbols will be used instead and indirection is avoided. This change restores static initialization for network stack global variables, restores support for non-global symbols and types, eliminates the need for many subsystem constructors, eliminates large per-subsystem structures that caused many binary compatibility issues both for monitoring applications (netstat) and kernel modules, removes the per-function INIT_VNET_*() macros throughout the stack, eliminates the need for vnet_symmap ksym(2) munging, and eliminates duplicate definitions of virtualized globals under VIMAGE_GLOBALS. Bump __FreeBSD_version and update UPDATING. Portions submitted by: bz Reviewed by: bz, zec Discussed with: gnn, jamie, jeff, jhb, julian, sam Suggested by: peter Approved by: re (kensmith)
2009-07-14 22:48:30 +00:00
&VNET_NAME(max_gif_nesting), 0, "Max nested tunnels");
static int
2013-11-15 12:12:50 +00:00
gif_clone_create(struct if_clone *ifc, int unit, caddr_t params)
{
struct gif_softc *sc;
2004-07-06 03:26:26 +00:00
sc = malloc(sizeof(struct gif_softc), M_GIF, M_WAITOK | M_ZERO);
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
sc->gif_fibnum = curthread->td_proc->p_fibnum;
GIF2IFP(sc) = if_alloc(IFT_GIF);
GIF2IFP(sc)->if_softc = sc;
if_initname(GIF2IFP(sc), gifname, unit);
GIF2IFP(sc)->if_addrlen = 0;
GIF2IFP(sc)->if_mtu = GIF_MTU;
GIF2IFP(sc)->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
GIF2IFP(sc)->if_ioctl = gif_ioctl;
GIF2IFP(sc)->if_transmit = gif_transmit;
GIF2IFP(sc)->if_qflush = gif_qflush;
GIF2IFP(sc)->if_output = gif_output;
#ifdef VIMAGE
GIF2IFP(sc)->if_reassign = gif_reassign;
#endif
2015-10-03 09:15:23 +00:00
GIF2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE;
GIF2IFP(sc)->if_capenable |= IFCAP_LINKSTATE;
if_attach(GIF2IFP(sc));
bpfattach(GIF2IFP(sc), DLT_NULL, sizeof(u_int32_t));
2001-09-26 23:50:17 +00:00
if (ng_gif_attach_p != NULL)
(*ng_gif_attach_p)(GIF2IFP(sc));
return (0);
}
#ifdef VIMAGE
static void
gif_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
char *unused __unused)
{
struct gif_softc *sc;
sx_xlock(&gif_ioctl_sx);
sc = ifp->if_softc;
if (sc != NULL)
gif_delete_tunnel(sc);
sx_xunlock(&gif_ioctl_sx);
}
#endif /* VIMAGE */
static void
2013-11-15 12:12:50 +00:00
gif_clone_destroy(struct ifnet *ifp)
{
struct gif_softc *sc;
sx_xlock(&gif_ioctl_sx);
sc = ifp->if_softc;
gif_delete_tunnel(sc);
2001-09-26 23:50:17 +00:00
if (ng_gif_detach_p != NULL)
(*ng_gif_detach_p)(ifp);
bpfdetach(ifp);
if_detach(ifp);
ifp->if_softc = NULL;
sx_xunlock(&gif_ioctl_sx);
GIF_WAIT();
if_free(ifp);
free(sc, M_GIF);
}
static void
vnet_gif_init(const void *unused __unused)
{
V_gif_cloner = if_clone_simple(gifname, gif_clone_create,
gif_clone_destroy, 0);
#ifdef INET
in_gif_init();
#endif
#ifdef INET6
in6_gif_init();
#endif
}
VNET_SYSINIT(vnet_gif_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
vnet_gif_init, NULL);
static void
vnet_gif_uninit(const void *unused __unused)
{
if_clone_detach(V_gif_cloner);
#ifdef INET
in_gif_uninit();
#endif
#ifdef INET6
in6_gif_uninit();
#endif
}
VNET_SYSUNINIT(vnet_gif_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
vnet_gif_uninit, NULL);
static int
2013-11-15 12:12:50 +00:00
gifmodevent(module_t mod, int type, void *data)
{
switch (type) {
case MOD_LOAD:
case MOD_UNLOAD:
break;
default:
return (EOPNOTSUPP);
}
return (0);
}
static moduledata_t gif_mod = {
"if_gif",
gifmodevent,
0
};
DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(if_gif, 1);
struct gif_list *
gif_hashinit(void)
{
struct gif_list *hash;
int i;
hash = malloc(sizeof(struct gif_list) * GIF_HASH_SIZE,
M_GIF, M_WAITOK);
for (i = 0; i < GIF_HASH_SIZE; i++)
CK_LIST_INIT(&hash[i]);
return (hash);
}
void
gif_hashdestroy(struct gif_list *hash)
{
free(hash, M_GIF);
}
#define MTAG_GIF 1080679712
static int
gif_transmit(struct ifnet *ifp, struct mbuf *m)
{
struct gif_softc *sc;
struct etherip_header *eth;
#ifdef INET
struct ip *ip;
#endif
#ifdef INET6
struct ip6_hdr *ip6;
uint32_t t;
#endif
uint32_t af;
uint8_t proto, ecn;
int error;
NET_EPOCH_ASSERT();
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m);
if (error) {
m_freem(m);
goto err;
}
#endif
error = ENETDOWN;
sc = ifp->if_softc;
if ((ifp->if_flags & IFF_MONITOR) != 0 ||
(ifp->if_flags & IFF_UP) == 0 ||
(ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
sc->gif_family == 0 ||
(error = if_tunnel_check_nesting(ifp, m, MTAG_GIF,
V_max_gif_nesting)) != 0) {
m_freem(m);
goto err;
}
/* Now pull back the af that we stashed in the csum_data. */
if (ifp->if_bridge)
af = AF_LINK;
else
af = m->m_pkthdr.csum_data;
m->m_flags &= ~(M_BCAST|M_MCAST);
M_SETFIB(m, sc->gif_fibnum);
BPF_MTAP2(ifp, &af, sizeof(af), m);
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len);
/* inner AF-specific encapsulation */
ecn = 0;
switch (af) {
#ifdef INET
case AF_INET:
proto = IPPROTO_IPV4;
if (m->m_len < sizeof(struct ip))
m = m_pullup(m, sizeof(struct ip));
if (m == NULL) {
error = ENOBUFS;
goto err;
}
ip = mtod(m, struct ip *);
ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &ecn, &ip->ip_tos);
break;
#endif
#ifdef INET6
case AF_INET6:
proto = IPPROTO_IPV6;
if (m->m_len < sizeof(struct ip6_hdr))
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL) {
error = ENOBUFS;
goto err;
}
t = 0;
ip6 = mtod(m, struct ip6_hdr *);
ip6_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &t, &ip6->ip6_flow);
ecn = (ntohl(t) >> 20) & 0xff;
break;
#endif
case AF_LINK:
proto = IPPROTO_ETHERIP;
M_PREPEND(m, sizeof(struct etherip_header), M_NOWAIT);
if (m == NULL) {
error = ENOBUFS;
goto err;
}
eth = mtod(m, struct etherip_header *);
eth->eip_resvh = 0;
eth->eip_ver = ETHERIP_VERSION;
eth->eip_resvl = 0;
break;
default:
error = EAFNOSUPPORT;
m_freem(m);
goto err;
}
/* XXX should we check if our outer source is legal? */
/* dispatch to output logic based on outer AF */
switch (sc->gif_family) {
#ifdef INET
case AF_INET:
error = in_gif_output(ifp, m, proto, ecn);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gif_output(ifp, m, proto, ecn);
break;
#endif
default:
m_freem(m);
}
err:
if (error)
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
return (error);
}
static void
gif_qflush(struct ifnet *ifp __unused)
{
}
int
gif_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct route *ro)
{
uint32_t af;
if (dst->sa_family == AF_UNSPEC)
bcopy(dst->sa_data, &af, sizeof(af));
else
af = RO_GET_FAMILY(ro, dst);
/*
* Now save the af in the inbound pkt csum data, this is a cheat since
* we are using the inbound csum_data field to carry the af over to
* the gif_transmit() routine, avoiding using yet another mtag.
*/
m->m_pkthdr.csum_data = af;
return (ifp->if_transmit(ifp, m));
}
void
gif_input(struct mbuf *m, struct ifnet *ifp, int proto, uint8_t ecn)
{
struct etherip_header *eip;
#ifdef INET
struct ip *ip;
#endif
#ifdef INET6
struct ip6_hdr *ip6;
uint32_t t;
#endif
struct ether_header *eh;
struct ifnet *oldifp;
int isr, n, af;
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 (ifp == NULL) {
/* just in case */
m_freem(m);
return;
}
m->m_pkthdr.rcvif = ifp;
m_clrprotoflags(m);
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
af = AF_INET;
if (m->m_len < sizeof(struct ip))
m = m_pullup(m, sizeof(struct ip));
if (m == NULL)
goto drop;
ip = mtod(m, struct ip *);
if (ip_ecn_egress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &ecn, &ip->ip_tos) == 0) {
m_freem(m);
goto drop;
}
break;
#endif
#ifdef INET6
case IPPROTO_IPV6:
af = AF_INET6;
if (m->m_len < sizeof(struct ip6_hdr))
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL)
goto drop;
t = htonl((uint32_t)ecn << 20);
ip6 = mtod(m, struct ip6_hdr *);
if (ip6_ecn_egress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &t, &ip6->ip6_flow) == 0) {
m_freem(m);
goto drop;
}
break;
#endif
case IPPROTO_ETHERIP:
af = AF_LINK;
break;
default:
m_freem(m);
goto drop;
}
#ifdef MAC
mac_ifnet_create_mbuf(ifp, m);
#endif
Fix the following bpf(4) race condition which can result in a panic: (1) bpf peer attaches to interface netif0 (2) Packet is received by netif0 (3) ifp->if_bpf pointer is checked and handed off to bpf (4) bpf peer detaches from netif0 resulting in ifp->if_bpf being initialized to NULL. (5) ifp->if_bpf is dereferenced by bpf machinery (6) Kaboom This race condition likely explains the various different kernel panics reported around sending SIGINT to tcpdump or dhclient processes. But really this race can result in kernel panics anywhere you have frequent bpf attach and detach operations with high packet per second load. Summary of changes: - Remove the bpf interface's "driverp" member - When we attach bpf interfaces, we now set the ifp->if_bpf member to the bpf interface structure. Once this is done, ifp->if_bpf should never be NULL. [1] - Introduce bpf_peers_present function, an inline operation which will do a lockless read bpf peer list associated with the interface. It should be noted that the bpf code will pickup the bpf_interface lock before adding or removing bpf peers. This should serialize the access to the bpf descriptor list, removing the race. - Expose the bpf_if structure in bpf.h so that the bpf_peers_present function can use it. This also removes the struct bpf_if; hack that was there. - Adjust all consumers of the raw if_bpf structure to use bpf_peers_present Now what happens is: (1) Packet is received by netif0 (2) Check to see if bpf descriptor list is empty (3) Pickup the bpf interface lock (4) Hand packet off to process From the attach/detach side: (1) Pickup the bpf interface lock (2) Add/remove from bpf descriptor list Now that we are storing the bpf interface structure with the ifnet, there is is no need to walk the bpf interface list to locate the correct bpf interface. We now simply look up the interface, and initialize the pointer. This has a nice side effect of changing a bpf interface attach operation from O(N) (where N is the number of bpf interfaces), to O(1). [1] From now on, we can no longer check ifp->if_bpf to tell us whether or not we have any bpf peers that might be interested in receiving packets. In collaboration with: sam@ MFC after: 1 month
2006-06-02 19:59:33 +00:00
if (bpf_peers_present(ifp->if_bpf)) {
uint32_t af1 = af;
bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m);
}
if ((ifp->if_flags & IFF_MONITOR) != 0) {
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
m_freem(m);
return;
}
2001-09-26 23:50:17 +00:00
if (ng_gif_input_p != NULL) {
(*ng_gif_input_p)(ifp, &m, af);
2001-09-26 23:50:17 +00:00
if (m == NULL)
goto drop;
2001-09-26 23:50:17 +00:00
}
/*
* Put the packet to the network layer input queue according to the
* specified address family.
* Note: older versions of gif_input directly called network layer
* input functions, e.g. ip6_input, here. We changed the policy to
* prevent too many recursive calls of such input functions, which
* might cause kernel panic. But the change may introduce another
* problem; if the input queue is full, packets are discarded.
* The kernel stack overflow really happened, and we believed
* queue-full rarely occurs, so we changed the policy.
*/
switch (af) {
#ifdef INET
case AF_INET:
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
isr = NETISR_IPV6;
break;
#endif
case AF_LINK:
n = sizeof(struct etherip_header) +
sizeof(struct ether_header);
if (n > m->m_len)
m = m_pullup(m, n);
if (m == NULL)
goto drop;
eip = mtod(m, struct etherip_header *);
if (eip->eip_ver != ETHERIP_VERSION) {
/* discard unknown versions */
m_freem(m);
goto drop;
}
m_adj_decap(m, sizeof(struct etherip_header));
m->m_flags &= ~(M_BCAST|M_MCAST);
m->m_pkthdr.rcvif = ifp;
if (ifp->if_bridge) {
oldifp = ifp;
eh = mtod(m, struct ether_header *);
if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
if (ETHER_IS_BROADCAST(eh->ether_dhost))
m->m_flags |= M_BCAST;
else
m->m_flags |= M_MCAST;
if_inc_counter(ifp, IFCOUNTER_IMCASTS, 1);
}
BRIDGE_INPUT(ifp, m);
if (m != NULL && ifp != oldifp) {
/*
* The bridge gave us back itself or one of the
* members for which the frame is addressed.
*/
ether_demux(ifp, m);
return;
}
}
if (m != NULL)
m_freem(m);
return;
default:
2001-09-26 23:50:17 +00:00
if (ng_gif_input_orphan_p != NULL)
(*ng_gif_input_orphan_p)(ifp, m, af);
2001-09-26 23:50:17 +00:00
else
m_freem(m);
return;
}
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
M_SETFIB(m, ifp->if_fib);
netisr_dispatch(isr, m);
return;
drop:
if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
}
static int
2013-11-15 12:12:50 +00:00
gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct ifreq *ifr = (struct ifreq*)data;
struct gif_softc *sc;
u_int options;
int error;
switch (cmd) {
case SIOCSIFADDR:
ifp->if_flags |= IFF_UP;
case SIOCADDMULTI:
case SIOCDELMULTI:
case SIOCGIFMTU:
case SIOCSIFFLAGS:
return (0);
case SIOCSIFMTU:
if (ifr->ifr_mtu < GIF_MTU_MIN ||
ifr->ifr_mtu > GIF_MTU_MAX)
return (EINVAL);
else
ifp->if_mtu = ifr->ifr_mtu;
return (0);
}
sx_xlock(&gif_ioctl_sx);
sc = ifp->if_softc;
if (sc == NULL) {
error = ENXIO;
goto bad;
}
error = 0;
switch (cmd) {
case SIOCDIFPHYADDR:
if (sc->gif_family == 0)
break;
gif_delete_tunnel(sc);
break;
#ifdef INET
case SIOCSIFPHYADDR:
case SIOCGIFPSRCADDR:
case SIOCGIFPDSTADDR:
error = in_gif_ioctl(sc, cmd, data);
break;
#endif
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
case SIOCGIFPSRCADDR_IN6:
case SIOCGIFPDSTADDR_IN6:
error = in6_gif_ioctl(sc, cmd, data);
break;
#endif
case SIOCGTUNFIB:
ifr->ifr_fib = sc->gif_fibnum;
break;
case SIOCSTUNFIB:
if ((error = priv_check(curthread, PRIV_NET_GIF)) != 0)
break;
if (ifr->ifr_fib >= rt_numfibs)
error = EINVAL;
else
sc->gif_fibnum = ifr->ifr_fib;
break;
case GIFGOPTS:
options = sc->gif_options;
error = copyout(&options, ifr_data_get_ptr(ifr),
sizeof(options));
break;
case GIFSOPTS:
if ((error = priv_check(curthread, PRIV_NET_GIF)) != 0)
break;
error = copyin(ifr_data_get_ptr(ifr), &options,
sizeof(options));
2009-06-09 08:09:30 +00:00
if (error)
break;
if (options & ~GIF_OPTMASK) {
2009-06-09 08:09:30 +00:00
error = EINVAL;
Rework IP encapsulation handling code. Currently it has several disadvantages: - it uses single mutex to protect internal structures. It is used by data- and control- path, thus there are no parallelism at all. - it uses single list to keep encap handlers for both INET and INET6 families. - struct encaptab keeps unneeded information (src, dst, masks, protosw), that isn't used by code in the source tree. - matches are prioritized and when many tunneling interfaces are registered, encapcheck handler of each interface is invoked for each packet. The search takes O(n) for n interfaces. All this work is done with exclusive lock held. What this patch includes: - the datapath is converted to be lockless using epoch(9) KPI. - struct encaptab now linked using CK_LIST. - all unused fields removed from struct encaptab. Several new fields addedr: min_length is the minimum packet length, that encapsulation handler expects to see; exact_match is maximum number of bits, that can return an encapsulation handler, when it wants to consume a packet. - IPv6 and IPv4 handlers are stored in separate lists; - added new "encap_lookup_t" method, that will be used later. It is targeted to speedup lookup of needed interface, when gif(4)/gre(4) have many interfaces. - the need to use protosw structure is eliminated. The only pr_input method was used from this structure, so I don't see the need to keep using it. - encap_input_t method changed to avoid using mbuf tags to store softc pointer. Now it is passed directly trough encap_input_t method. encap_getarg() funtions is removed. - all sockaddr structures and code that uses them removed. We don't have any code in the tree that uses them. All consumers use encap_attach_func() method, that relies on invoking of encapcheck() to determine the needed handler. - introduced struct encap_config, it contains parameters of encap handler that is going to be registered by encap_attach() function. - encap handlers are stored in lists ordered by exact_match value, thus handlers that need more bits to match will be checked first, and if encapcheck method returns exact_match value, the search will be stopped. - all current consumers changed to use new KPI. Reviewed by: mmacy Sponsored by: Yandex LLC Differential Revision: https://reviews.freebsd.org/D15617
2018-06-05 20:51:01 +00:00
break;
}
if (sc->gif_options != options) {
switch (sc->gif_family) {
#ifdef INET
case AF_INET:
error = in_gif_setopts(sc, options);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gif_setopts(sc, options);
break;
#endif
default:
/* No need to invoke AF-handler */
sc->gif_options = options;
}
}
break;
default:
error = EINVAL;
break;
}
if (error == 0 && sc->gif_family != 0) {
if (
#ifdef INET
cmd == SIOCSIFPHYADDR ||
#endif
#ifdef INET6
cmd == SIOCSIFPHYADDR_IN6 ||
#endif
0) {
if_link_state_change(ifp, LINK_STATE_UP);
}
}
bad:
sx_xunlock(&gif_ioctl_sx);
return (error);
}
static void
gif_delete_tunnel(struct gif_softc *sc)
{
sx_assert(&gif_ioctl_sx, SA_XLOCKED);
if (sc->gif_family != 0) {
CK_LIST_REMOVE(sc, srchash);
CK_LIST_REMOVE(sc, chain);
/* Wait until it become safe to free gif_hdr */
GIF_WAIT();
free(sc->gif_hdr, M_GIF);
}
sc->gif_family = 0;
GIF2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
if_link_state_change(GIF2IFP(sc), LINK_STATE_DOWN);
}