Commit Graph

197 Commits

Author SHA1 Message Date
Alexander V. Chernikov
90d6251228 netlink: add rtsock-compatible header to use with netlink snl(3).
Some routing socket defines (`RTM_` and `RTA_` ones) clash with the ones
 used by the the Netlink.
As some rtsock definitions like interface flags or route flags are used in
 both netlink and rtsock, provide a convenient way to include those without
 running into the define collision.

Differential Revision: https://reviews.freebsd.org/D38982
MFC after:	2 weeks
2023-03-09 14:37:42 +00:00
Alexander V. Chernikov
1bcd230f95 netlink: add interface notification on link status / flags change.
* Add link-state change notifications by subscribing to ifnet_link_event.
 In the Linux netlink model, link state is reported in 2 places: first is
 the IFLA_OPERSTATE, which stores state per RFC2863.
 The second is an IFF_LOWER_UP interface flag. As many applications rely
 on the latter, reserve 1 bit from if_flags, named as IFF_NETLINK_1.
 This flag is mapped to IFF_LOWER_UP in the netlink headers. This is done
 to avoid making applications think this flag is actually
 supported / presented in non-netlink outputs.
* Add flag change notifications, by hooking into rt_ifmsg().
 In the netlink model, notification should include the bitmask for the
 change flags. Update rt_ifmsg() to include such bitmask.

Differential Revision: https://reviews.freebsd.org/D37597
2022-12-09 11:20:07 +00:00
Gleb Smirnoff
1922eb3e9c protosw: retire pr_slowtimo and pr_fasttimo
They were useful many years ago, when the callwheel was not efficient,
and the kernel tried to have as little callout entries scheduled as
possible.

Reviewed by:		tuexen, melifaro
Differential revision:	https://reviews.freebsd.org/D36163
2022-08-17 11:50:31 -07:00
Alexander V. Chernikov
036f1bc613 routing: retire rib_lookup_info()
This function was added in pre-epoch era ( 9a1b64d5a0 ) to
 provide public rtentry access interface & hide rtentry internals.
The implementation is based on the large on-stack copying and
 refcounting of the referenced objects (ifa/ifp).
It has become obsolete after epoch & nexthop introduction. Convert
 the last remaining user and remove the function itself.

Differential Revision: https://reviews.freebsd.org/D36197
2022-08-15 06:46:30 +00:00
Alexander V. Chernikov
d8b42ddcac rtsock: subscribe to ifnet eventhandlers instead of direct calls.
Stop treating rtsock as a "special" consumer and use already-provided
 ifaddr arrival/departure notifications.

MFC after:	2 weeks

Test Plan:
```
21:05 [0] m@devel0 route -n monitor

-> ifconfig vtnet0.2 create

got message of size 24 on Tue Aug  9 21:05:44 2022
RTM_IFANNOUNCE: interface arrival/departure: len 24, if# 3, what: arrival

got message of size 168 on Tue Aug  9 21:05:54 2022
RTM_IFINFO: iface status change: len 168, if# 3, link: up, flags:<BROADCAST,RUNNING,SIMPLEX,MULTICAST>

-> ifconfig vtnet0.2 destroy

got message of size 24 on Tue Aug  9 21:05:54 2022
RTM_IFANNOUNCE: interface arrival/departure: len 24, if# 3, what: departure

```

Reviewed By: glebius
Differential Revision: https://reviews.freebsd.org/D36095
MFC after:	2 weeks
2022-08-11 20:36:59 +00:00
Alexander V. Chernikov
66230639ce routing: split nexthop creation and rtentry creation.
This change is required for the upcoming introduction of the next
 nexhop-based operations KPI, as it will create rtentry and nexthops
 at different stages of route table modification.

Differential Revision: https://reviews.freebsd.org/D36072
MFC after:	2 weeks
2022-08-10 18:27:13 +00:00
Gordon Bergling
23677398ca net(3): Fix a typo in a source code comment
- s/paramenters/parameters/

MFC after:	3 days
2022-04-02 09:24:48 +02:00
Alexander V. Chernikov
63f7f3921b routing: Add unified level-based logging support for the routing subsystem.
Summary: MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D33664
2021-12-29 21:30:18 +00:00
Zhenlei Huang
62e1a437f3 routing: Allow using IPv6 next-hops for IPv4 routes (RFC 5549).
Implement kernel support for RFC 5549/8950.

* Relax control plane restrictions and allow specifying IPv6 gateways
 for IPv4 routes. This behavior is controlled by the
 net.route.rib_route_ipv6_nexthop sysctl (on by default).

* Always pass final destination in ro->ro_dst in ip_forward().

* Use ro->ro_dst to exract packet family inside if_output() routines.
 Consistently use RO_GET_FAMILY() macro to handle ro=NULL case.

* Pass extracted family to nd6_resolve() to get the LLE with proper encap.
 It leverages recent lltable changes committed in c541bd368f.

Presence of the functionality can be checked using ipv4_rfc5549_support feature(3).
Example usage:
  route add -net 192.0.0.0/24 -inet6 fe80::5054:ff:fe14:e319%vtnet0

Differential Revision: https://reviews.freebsd.org/D30398
MFC after:	2 weeks
2021-08-22 22:56:08 +00:00
Mark Johnston
8e8f1cc9bb Re-enable network ioctls in capability mode
This reverts a portion of 274579831b ("capsicum: Limit socket
operations in capability mode") as at least rtsol and dhcpcd rely on
being able to configure network interfaces while in capability mode.

Reported by:	bapt, Greg V
Sponsored by:	The FreeBSD Foundation
2021-04-23 09:22:49 -04:00
Mark Johnston
274579831b capsicum: Limit socket operations in capability mode
Capsicum did not prevent certain privileged networking operations,
specifically creation of raw sockets and network configuration ioctls.
However, these facilities can be used to circumvent some of the
restrictions that capability mode is supposed to enforce.

Add capability mode checks to disallow network configuration ioctls and
creation of sockets other than PF_LOCAL and SOCK_DGRAM/STREAM/SEQPACKET
internet sockets.

Reviewed by:	oshogbo
Discussed with:	emaste
Reported by:	manu
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D29423
2021-04-07 14:32:56 -04:00
Alexander V. Chernikov
b1d63265ac Flush remaining routes from the routing table during VNET shutdown.
Summary:
This fixes rtentry leak for the cloned interfaces created inside the
 VNET.

PR:	253998
Reported by:	rashey at superbox.pl
MFC after:	3 days

Loopback teardown order is `SI_SUB_INIT_IF`, which happens after `SI_SUB_PROTO_DOMAIN` (route table teardown).
Thus, any route table operations are too late to schedule.
As the intent of the vnet teardown procedures to minimise the amount of effort by doing global cleanups instead of per-interface ones, address this by adding a relatively light-weight routing table cleanup function, `rib_flush_routes()`.
It removes all remaining routes from the routing table and schedules the deletion, which will happen later, when `rtables_destroy()` waits for the current epoch to finish.

Test Plan:
```
set_skip:set_skip_group_lo  ->  passed  [0.053s]
tail -n 200 /var/log/messages | grep rtentry
```

Reviewers: #network, kp, bz

Reviewed By: kp

Subscribers: imp, ae

Differential Revision: https://reviews.freebsd.org/D29116
2021-03-10 21:10:14 +00:00
Alexander V. Chernikov
64d5c27777 Remove now-unused RTF_RNH_LOCKED route flag.
MFC after:	1 week
2021-02-15 20:49:59 +00:00
Alexander V. Chernikov
81728a538d Split rtinit() into multiple functions.
rtinit[1]() is a function used to add or remove interface address prefix routes,
  similar to ifa_maintain_loopback_route().
It was intended to be family-agnostic. There is a problem with this approach
 in reality.

1) IPv6 code does not use it for the ifa routes. There is a separate layer,
  nd6_prelist_(), providing interface for maintaining interface routes. Its part,
  responsible for the actual route table interaction, mimics rtenty() code.

2) rtinit tries to combine multiple actions in the same function: constructing
  proper route attributes and handling iterations over multiple fibs, for the
  non-zero net.add_addr_allfibs use case. It notably increases the code complexity.

3) dstaddr handling. flags parameter re-uses RTF_ flags. As there is no special flag
 for p2p connections, host routes and p2p routes are handled in the same way.
 Additionally, mapping IFA flags to RTF flags makes the interface pretty messy.
 It make rtinit() to clash with ifa_mainain_loopback_route() for IPV4 interface
 aliases.

4) rtinit() is the last customer passing non-masked prefixes to rib_action(),
 complicating rib_action() implementation.

5) rtinit() coupled ifa announce/withdrawal notifications, producing "false positive"
 ifa messages in certain corner cases.

To address all these points, the following has been done:

* rtinit() has been split into multiple functions:
- Route attribute construction were moved to the per-address-family functions,
 dealing with (2), (3) and (4).
- funnction providing net.add_addr_allfibs handling and route rtsock notificaions
 is the new routing table inteface.
- rtsock ifa notificaion has been moved out as well. resulting set of funcion are only
 responsible for the actual route notifications.

Side effects:
* /32 alias does not result in interface routes (/32 route and "host" route)
* RTF_PINNED is now set for IPv6 prefixes corresponding to the interface addresses

Differential revision:	https://reviews.freebsd.org/D28186
2021-01-16 22:42:41 +00:00
Alexander V. Chernikov
d68cf57b7f Refactor rt_addrmsg() and rt_routemsg().
Summary:
* Refactor rt_addrmsg(): make V_rt_add_addr_allfibs decision locally.
* Fix rt_routemsg() and multipath by accepting nexthop instead of interface pointer.
* Refactor rtsock_routemsg(): avoid accessing rtentry fields directly.
* Simplify in_addprefix() by moving prefix search to a separate  function.

Reviewers: #network

Subscribers: imp, ae, bz

Differential Revision: https://reviews.freebsd.org/D28011
2021-01-07 19:38:19 +00:00
Alexander V. Chernikov
77df2c21cb Renumber NHR_* flags after NHR_IFAIF removal in r368127.
Suggested by:	rpokala
2020-11-30 21:42:55 +00:00
Alexander V. Chernikov
b712e3e343 Refactor fib4/fib6 functions.
No functional changes.

* Make lookup path of fib<4|6>_lookup_debugnet() separate functions
 (fib<46>_lookup_rt()). These will be used in the control plane code
 requiring unlocked radix operations and actual prefix pointer.
* Make lookup part of fib<4|6>_check_urpf() separate functions.
 This change simplifies the switch to alternative lookup implementations,
 which helps algorithmic lookups introduction.
* While here, use static initializers for IPv4/IPv6 keys

Differential Revision:	https://reviews.freebsd.org/D27405
2020-11-29 13:41:49 +00:00
Alexander V. Chernikov
7a6dc73c98 Cleanup nexthops request flags:
* remove NHR_IFAIF as it was used by previous version of nexthop KPI
* update NHR_REF description
2020-11-28 15:11:59 +00:00
Alexander V. Chernikov
7511a63825 Refactor rib iterator functions.
* Make rib_walk() order of arguments consistent with the rest of RIB api
* Add rib_walk_ext() allowing to exec callback before/after iteration.
* Rename rt_foreach_fib_walk_del -> rib_foreach_table_walk_del
* Rename rt_forach_fib_walk -> rib_foreach_table_walk
* Move rib_foreach_table_walk{_del} to route/route_helpers.c
* Slightly refactor rib_foreach_table_walk{_del} to make the implementation
 consistent and prepare for upcoming iterator optimizations.

Differential Revision:	https://reviews.freebsd.org/D27219
2020-11-22 20:21:10 +00:00
Alexander V. Chernikov
0c325f53f1 Implement flowid calculation for outbound connections to balance
connections over multiple paths.

Multipath routing relies on mbuf flowid data for both transit
 and outbound traffic. Current code fills mbuf flowid from inp_flowid
 for connection-oriented sockets. However, inp_flowid is currently
 not calculated for outbound connections.

This change creates simple hashing functions and starts calculating hashes
 for TCP,UDP/UDP-Lite and raw IP if multipath routes are present in the
 system.

Reviewed by:	glebius (previous version),ae
Differential Revision:	https://reviews.freebsd.org/D26523
2020-10-18 17:15:47 +00:00
Alexander V. Chernikov
fedeb08b6a Introduce scalable route multipath.
This change is based on the nexthop objects landed in D24232.

The change introduces the concept of nexthop groups.
Each group contains the collection of nexthops with their
 relative weights and a dataplane-optimized structure to enable
 efficient nexthop selection.

Simular to the nexthops, nexthop groups are immutable. Dataplane part
 gets compiled during group creation and is basically an array of
 nexthop pointers, compiled w.r.t their weights.

With this change, `rt_nhop` field of `struct rtentry` contains either
 nexthop or nexthop group. They are distinguished by the presense of
 NHF_MULTIPATH flag.
All dataplane lookup functions returns pointer to the nexthop object,
leaving nexhop groups details inside routing subsystem.

User-visible changes:

The change is intended to be backward-compatible: all non-mpath operations
 should work as before with ROUTE_MPATH and net.route.multipath=1.

All routes now comes with weight, default weight is 1, maximum is 2^24-1.

Current maximum multipath group width is statically set to 64.
 This will become sysctl-tunable in the followup changes.

Using functionality:
* Recompile kernel with ROUTE_MPATH
* set net.route.multipath to 1

route add -6 2001:db8::/32 2001:db8::2 -weight 10
route add -6 2001:db8::/32 2001:db8::3 -weight 20

netstat -6On

Nexthop groups data

Internet6:
GrpIdx  NhIdx     Weight   Slots                                 Gateway     Netif  Refcnt
1         ------- ------- ------- --------------------------------------- ---------       1
              13      10       1                             2001:db8::2     vlan2
              14      20       2                             2001:db8::3     vlan2

Next steps:
* Land outbound hashing for locally-originated routes ( D26523 ).
* Fix net/bird multipath (net/frr seems to work fine)
* Add ROUTE_MPATH to GENERIC
* Set net.route.multipath=1 by default

Tested by:	olivier
Reviewed by:	glebius
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D26449
2020-10-03 10:47:17 +00:00
Alexander V. Chernikov
2259a03020 Rework part of routing code to reduce difference to D26449.
* Split rt_setmetrics into get_info_weight() and rt_set_expire_info(),
 as these two can be applied at different entities and at different times.
* Start filling route weight in route change notifications
* Pass flowid to UDP/raw IP route lookups
* Rework nd6_subscription_cb() and sysctl_dumpentry() to prepare for the fact
 that rtentry can contain multiple nexthops.

Differential Revision:	https://reviews.freebsd.org/D26497
2020-09-21 20:02:26 +00:00
Alexander V. Chernikov
f5247a232a Make net.fibs growable.
Allow to dynamically grow the amount of fibs in each vnet.

This change alters current behavior. Currently, if one defines
 ROUTETABLES > 1 in the kernel config, each vnet will be created
 with the number of fibs defined in the kernel config.
 After this commit vnets will be created with fibs=1.

Dynamic net.fibs is not compatible with net.add_addr_allfibs.
 The plan is to deprecate the latter and make
 net.add_addr_allfibs=0 default behaviour.

Reviewed by:	glebius
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D26062
2020-08-21 21:34:52 +00:00
Alexander V. Chernikov
6cbadc4234 Move rtzone handling code to net/route_ctl.c
After moving the route control plane code from net/route.c,
 all rtzone users ended up being in net/route_ctl.c.
Move uma(9) rtzone setup/teardown code to net/route_ctl.c as well
 to have everything in a single place.

While here, remove custom initializers from the zone.
It was added originally to avoid setup/teardown of costy per-cpu couters.
With these counters removed, the only remaining job was avoiding rte mutex
 setup/teardown. Mutex setup is relatively cheap. Additionally, this mutex
 will soon be removed. With that in mind, there is no sense in keeping
 custom zone callbacks.

Differential Revision:	https://reviews.freebsd.org/D26051
2020-08-13 18:35:29 +00:00
Alexander V. Chernikov
e1c05fd290 Transition from rtrequest1_fib() to rib_action().
Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
 in6_rtrequest, rtrequest_fib> and their uses and switch to
 to rib_action(). This is part of the new routing KPI.

Submitted by: Neel Chauhan <neel AT neelc DOT org>
Differential Revision: https://reviews.freebsd.org/D25546
2020-07-21 19:56:13 +00:00
Alexander V. Chernikov
725871230d Temporarly revert r363319 to unbreak the build.
Reported by:	CI
Pointy hat to: melifaro
2020-07-19 10:53:15 +00:00
Alexander V. Chernikov
8cee15d9e4 Transition from rtrequest1_fib() to rib_action().
Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
 in6_rtrequest, rtrequest_fib> and their uses and switch to
to rib_action(). This is part of the new routing KPI.

Submitted by:	Neel Chauhan <neel AT neelc DOT org>
Differential Revision:	https://reviews.freebsd.org/D25546
2020-07-19 09:29:27 +00:00
Alexander V. Chernikov
da187ddb3d * Add rib_<add|del|change>_route() functions to manipulate the routing table.
The main driver for the change is the need to improve notification mechanism.
Currently callers guess the operation data based on the rtentry structure
 returned in case of successful operation result. There are two problems with
 this appoach. First is that it doesn't provide enough information for the
 upcoming multipath changes, where rtentry refers to a new nexthop group,
 and there is no way of guessing which paths were added during the change.
 Second is that some rtentry fields can change during notification and
 protecting from it by requiring customers to unlock rtentry is not desired.

Additionally, as the consumers such as rtsock do know which operation they
 request in advance, making explicit add/change/del versions of the functions
 makes sense, especially given the functions don't share a lot of code.

With that in mind, introduce rib_cmd_info notification structure and
 rib_<add|del|change>_route() functions, with mandatory rib_cmd_info pointer.
 It will be used in upcoming generalized notifications.

* Move definitions of the new functions and some other functions/structures
 used for the routing table manipulation to a separate header file,
 net/route/route_ctl.h. net/route.h is a frequently used file included in
 ~140 places in kernel, and 90% of the users don't need these definitions.

Reviewed by:		ae
Differential Revision:	https://reviews.freebsd.org/D25067
2020-06-01 20:49:42 +00:00
Alexander V. Chernikov
e7403d0230 Revert r361704, it accidentally committed merged D25067 and D25070. 2020-06-01 20:40:40 +00:00
Alexander V. Chernikov
79674562b8 * Add rib_<add|del|change>_route() functions to manipulate the routing table.
The main driver for the change is the need to improve notification mechanism.
Currently callers guess the operation data based on the rtentry structure
 returned in case of successful operation result. There are two problems with
 this appoach. First is that it doesn't provide enough information for the
 upcoming multipath changes, where rtentry refers to a new nexthop group,
 and there is no way of guessing which paths were added during the change.
 Second is that some rtentry fields can change during notification and
 protecting from it by requiring customers to unlock rtentry is not desired.

Additionally, as the consumers such as rtsock do know which operation they
 request in advance, making explicit add/change/del versions of the functions
 makes sense, especially given the functions don't share a lot of code.

With that in mind, introduce rib_cmd_info notification structure and
 rib_<add|del|change>_route() functions, with mandatory rib_cmd_info pointer.
 It will be used in upcoming generalized notifications.

* Move definitions of the new functions and some other functions/structures
 used for the routing table manipulation to a separate header file,
 net/route/route_ctl.h. net/route.h is a frequently used file included in
 ~140 places in kernel, and 90% of the users don't need these definitions.

Reviewed by:	ae
Differential Revision: https://reviews.freebsd.org/D25067
2020-06-01 20:32:02 +00:00
Alexander V. Chernikov
2bbab0af6d Use epoch(9) for rtentries to simplify control plane operations.
Currently the only reason of refcounting rtentries is the need to report
 the rtable operation details immediately after the execution.
Delaying rtentry reclamation allows to stop refcounting and simplify the code.
Additionally, this change allows to reimplement rib_lookup_info(), which
 is used by some of the customers to get the matching prefix along
 with nexthops, in more efficient way.

The change keeps per-vnet rtzone uma zone. It adds nh_vnet field to
 nhop_priv to be able to reliably set curvnet even during vnet teardown.
Rest of the reference counting code will be removed in the D24867 .

Differential Revision:	https://reviews.freebsd.org/D24866
2020-05-23 10:21:02 +00:00
Alexander V. Chernikov
d223372545 Remove rtalloc1(_fib) KPI.
Last user of rtalloc1() KPI has been eliminated in rS360631.
As kernel is now fully switched to use new routing KPI defined in
rS359823, remove old lookup functions.

Differential Revision:	https://reviews.freebsd.org/D24776
2020-05-10 09:34:48 +00:00
Alexander V. Chernikov
656442a718 Embed dst sockaddr into rtentry and remove rte packet counter
Currently each rtentry has dst&gateway allocated separately from another zone,
 bloating cache accesses.

Current 'struct rtentry' has 12 "mandatory" radix pointers in the beginning,
 leaving 4 usable pointers/32 bytes in the first 2 cache lines (amd64).
Fields needed for the datapath are destination sockaddr and rt_nhop.

So far it doesn't look like there is other routable addressing protocol other
 than IPv4/IPv6/MPLS, which uses keys longer than 20 bytes.
With that in mind, embed dst into struct rtentry, making the first 24 bytes
 of rtentry within 128 bytes. That is enough to make IPv6 address within first
 128 bytes.

It is still pretty easy to add code for supporting separately-allocated dst,
 however it doesn't make a lot of sense in having such code without a use case.

As rS359823 moved the gateway to the nexthop structure, the dst embedding change
 removes the need for any additional allocations done by rt_setgate().

Lastly, as a part of cleanup, remove counter(9) allocation code, as this field
 is not used in packet processing anymore.

Reviewed by:	ae
Differential Revision:	https://reviews.freebsd.org/D24669
2020-05-08 21:06:10 +00:00
Alexander V. Chernikov
682b902daf Add rib_lookup() sockaddr lookup wrapper and make ifa_ifwithroute use it.
Create rib_lookup() wrapper around per-af dataplane lookup functions.
This will help in the cases of having control plane af-agnostic code.

Switch ifa_ifwithroute() to use this function instead of rtalloc1().

Reviewed by:	ae
Differential Revision:	https://reviews.freebsd.org/D24731
2020-05-07 08:11:36 +00:00
Alexander V. Chernikov
fc88ecd31a Move route-specific ddb commands to route/route_ddb.c
Currently functionality resides in rtsock.c, which is a controlling
 interface, partially external to the routing subsystem.
Additionally, DDB-supporting functionality is > 100SLOC, which deserves
 a separate file.

Given that, move this functionality to a newly-created net/route/ subdir.

Reviewed by:	cem
Differential Revision:	https://reviews.freebsd.org/D24561
2020-04-28 20:00:17 +00:00
Alexander V. Chernikov
fe6da72759 Move struct rtentry definition to nhop_var.h.
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
 features much faster.

This is one of the last changes, effectively moving struct rtentry
 definition to a net/route_var.h header, internal to the routing subsystem.

Differential Revision:	https://reviews.freebsd.org/D24580
2020-04-28 18:42:30 +00:00
Alexander V. Chernikov
1b0051bada Eliminate now-unused parts of old routing KPI.
r360292 switched most of the remaining routing customers to a new KPI,
 leaving a bunch of wrappers for old routing lookup functions unused.

Remove them from the tree as a part of routing cleanup.

Differential Revision:	https://reviews.freebsd.org/D24569
2020-04-28 07:25:34 +00:00
Alexander V. Chernikov
57e70e4471 Fix userland build broken by r360292. 2020-04-25 09:25:06 +00:00
Alexander V. Chernikov
983066f05b Convert route caching to nexthop caching.
This change is build on top of nexthop objects introduced in r359823.

Nexthops are separate datastructures, containing all necessary information
 to perform packet forwarding such as gateway interface and mtu. Nexthops
 are shared among the routes, providing more pre-computed cache-efficient
 data while requiring less memory. Splitting the LPM code and the attached
 data solves multiple long-standing problems in the routing layer,
 drastically reduces the coupling with outher parts of the stack and allows
 to transparently introduce faster lookup algorithms.

Route caching was (re)introduced to minimise (slow) routing lookups, allowing
 for notably better performance for large TCP senders. Caching works by
 acquiring rtentry reference, which is protected by per-rtentry mutex.
 If the routing table is changed (checked by comparing the rtable generation id)
 or link goes down, cache record gets withdrawn.

Nexthops have the same reference counting interface, backed by refcount(9).
This change merely replaces rtentry with the actual forwarding nextop as a
 cached object, which is mostly mechanical. Other moving parts like cache
 cleanup on rtable change remains the same.

Differential Revision:	https://reviews.freebsd.org/D24340
2020-04-25 09:06:11 +00:00
Alexander V. Chernikov
5cdc484410 Fix userland build broken by r360014. 2020-04-16 17:53:23 +00:00
Alexander V. Chernikov
539642a29d Add nhop parameter to rti_filter callback.
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 change is one of the ongoing changes to eliminate direct
 struct rtentry field accesses.

Additionally, with the followup multipath changes, single rtentry can point
 to multiple nexthops.

With that in mind, convert rti_filter callback used when traversing the
 routing table to accept pair (rt, nhop) instead of nexthop.

Reviewed by:	ae
Differential Revision:	https://reviews.freebsd.org/D24440
2020-04-16 17:20:18 +00:00
Alexander V. Chernikov
dd4776f0cc Reorganise nd6 notification code to avoid direct rtentry field access.
One of the goals of the new routing KPI defined in r359823 is to entirely hide
 `struct rtentry` from the consumers. Doing so will allow to improve routing
 subsystem internals and deliver features more easily. This change is one of
  the ongoing changes to eliminate direct struct rtentry field accesses.

It introduces rtfree_func() wrapper around RTFREE() and reorganises nd6 notification
 code to avoid accessing most of the rtentry fields.

Reviewed by:	ae
Differential Revision:	https://reviews.freebsd.org/D24404
2020-04-14 22:48:33 +00:00
Alexander V. Chernikov
a666325282 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
Alexander V. Chernikov
34a5582c47 Bring back redirect route expiration.
Redirect (and temporal) route expiration was broken a while ago.
This change brings route expiration back, with unified IPv4/IPv6 handling code.

It introduces net.inet.icmp.redirtimeout sysctl, allowing to set
 an expiration time for redirected routes. It defaults to 10 minutes,
 analogues with net.inet6.icmp6.redirtimeout.

Implementation uses separate file, route_temporal.c, as route.c is already
 bloated with tons of different functions.
Internally, expiration is implemented as an per-rnh callout scheduled when
 route with non-zero rt_expire time is added or rt_expire is changed.
 It does not add any overhead when no temporal routes are present.

Callout traverses entire routing tree under wlock, scheduling expired routes
 for deletion and calculating the next time it needs to be run. The rationale
 for such implemention is the following: typically workloads requiring large
 amount of routes have redirects turned off already, while the systems with
 small amount of routes will not inhibit large overhead during tree traversal.

This changes also fixes netstat -rn display of route expiration time, which
 has been broken since the conversion from kread() to sysctl.

Reviewed by:	bz
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D23075
2020-01-22 13:53:18 +00:00
Alexander V. Chernikov
ead85fe415 Add fibnum, family and vnet pointer to each rib head.
Having metadata such as fibnum or vnet in the struct rib_head
 is handy as it eases building functionality in the routing space.
This change is required to properly bring back route redirect support.

Reviewed by:	bz
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D23047
2020-01-09 17:21:00 +00:00
Alexander V. Chernikov
e02d3fe70c Fix rtsock route message generation for interface addresses.
Reviewed by:	olivier
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D22974
2020-01-07 21:16:30 +00:00
Alexander V. Chernikov
c83dda362e Split gigantic rtsock route_output() into smaller functions.
Amount of changes to the original code has been intentionally minimised
to ease diffing.
The changes are mostly mechanical, with the following exceptions:

* lltable handler is now called directly based of RTF_LLINFO flag presense.
* "report" logic for updating rtm in RTM_GET/RTM_DELETE has been simplified,
  fixing several potential use-after-free cases in rt_addrinfo.
* llable asserts has been replaced with error-returning, preventing kernel
  crashes when lltable gw af family is invalid (root required).

MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D22864
2019-12-31 17:26:53 +00:00
Gleb Smirnoff
185c3d2b93 Convert routing statistics to VNET_PCPUSTAT.
Submitted by:	ocochard
Reviewed by:	melifaro, glebius
Differential Revision:	https://reviews.freebsd.org/D22834
2019-12-17 02:02:26 +00:00
Gleb Smirnoff
fda454099b Make rt_getifa_fib() static. 2019-10-18 15:20:24 +00:00
Gleb Smirnoff
6ca363eb7b Existense of PCB route caching doesn't allow us to use new fast route
lookup KPI in ip_output() like it is already used in ip_forward().
However, when there is no PCB provided we can use fast KPI, gaining
performance advantage.

Typical case when ip_output() is called without a PCB pointer is a
sendto(2) on a not connected UDP socket. In practice DNS servers do
this.

Reviewed by:	melifaro
Differential Revision:	https://reviews.freebsd.org/D19804
2019-05-08 23:39:24 +00:00