ip6_setpktopts() can look up ifnets via ifnet_by_index(), which
is only safe in the net epoch. Ensure that callers are in the net
epoch before calling this function.
Sponsored by: Dell EMC Isilon
MFC after: 4 weeks
Reviewed by: donner, kp
Differential Revision: https://reviews.freebsd.org/D30630
The various protocol implementations are not very consistent about
freeing mbufs in error paths. In general, all protocols must free both
"m" and "control" upon an error, except if PRUS_NOTREADY is specified
(this is only implemented by TCP and unix(4) and requires further work
not handled in this diff), in which case "control" still must be freed.
This diff plugs various leaks in the pru_send implementations.
Reviewed by: tuexen
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D30151
Commit 81728a538 ("Split rtinit() into multiple functions.") removed
the initialization of sa6, but not one of its uses. This meant that we
were passing an uninitialized sockaddr as the address to
lltable_prefix_free(). Remove the variable outright to fix the problem.
The caller is expected to hold a reference on pr.
Fixes: 81728a538 ("Split rtinit() into multiple functions.")
Reported by: KMSAN
Reviewed by: donner
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D30166
Distinguish between truly invalid requests and those that fail because
we've already joined the group. Both cases fail, but differentiating
them allows userspace to make more informed decisions about what the
error means.
For example. radvd tries to join the all-routers group on every SIGHUP.
This fails, because it's already joined it, but this failure should be
ignored (rather than treated as a sign that the interface's multicast is
broken).
This puts us in line with OpenBSD, NetBSD and Linux.
Reviewed by: donner
MFC after: 1 week
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D30111
Several protocol methods take a sockaddr as input. In some cases the
sockaddr lengths were not being validated, or were validated after some
out-of-bounds accesses could occur. Add requisite checking to various
protocol entry points, and convert some existing checks to assertions
where appropriate.
Reported by: syzkaller+KASAN
Reviewed by: tuexen, melifaro
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29519
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
This is further rework of 08d9c92027. Now we carry the knowledge of
lock type all the way through tcp_input() and also into tcp_twcheck().
Ideally the rlocking for pure SYNs should propagate all the way into
the alternative TCP stacks, but not yet today.
This should close a race when socket is bind(2)-ed but not yet
listen(2)-ed and a SYN-packet arrives racing with listen(2), discovered
recently by pho@.
Adding support for TCP over UDP allows communication with
TCP stacks which can be implemented in userspace without
requiring special priviledges or specific support by the OS.
This is joint work with rrs.
Reviewed by: rrs
Sponsored by: Netflix, Inc.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D29469
When packet is a SYN packet, we don't need to modify any existing PCB.
Normally SYN arrives on a listening socket, we either create a syncache
entry or generate syncookie, but we don't modify anything with the
listening socket or associated PCB. Thus create a new PCB lookup
mode - rlock if listening. This removes the primary contention point
under SYN flood - the listening socket PCB.
Sidenote: when SYN arrives on a synchronized connection, we still
don't need write access to PCB to send a challenge ACK or just to
drop. There is only one exclusion - tcptw recycling. However,
existing entanglement of tcp_input + stacks doesn't allow to make
this change small. Consider this patch as first approach to the problem.
Reviewed by: rrs
Differential revision: https://reviews.freebsd.org/D29576
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
After length decisions, we've decided that the if_wg(4) driver and
related work is not yet ready to live in the tree. This driver has
larger security implications than many, and thus will be held to
more scrutiny than other drivers.
Please also see the related message sent to the freebsd-hackers@
and freebsd-arch@ lists by Kyle Evans <kevans@FreeBSD.org> on
2021/03/16, with the subject line "Removing WireGuard Support From Base"
for additional context.
This is the culmination of about a week of work from three developers to
fix a number of functional and security issues. This patch consists of
work done by the following folks:
- Jason A. Donenfeld <Jason@zx2c4.com>
- Matt Dunwoodie <ncon@noconroy.net>
- Kyle Evans <kevans@FreeBSD.org>
Notable changes include:
- Packets are now correctly staged for processing once the handshake has
completed, resulting in less packet loss in the interim.
- Various race conditions have been resolved, particularly w.r.t. socket
and packet lifetime (panics)
- Various tests have been added to assure correct functionality and
tooling conformance
- Many security issues have been addressed
- if_wg now maintains jail-friendly semantics: sockets are created in
the interface's home vnet so that it can act as the sole network
connection for a jail
- if_wg no longer fails to remove peer allowed-ips of 0.0.0.0/0
- if_wg now exports via ioctl a format that is future proof and
complete. It is additionally supported by the upstream
wireguard-tools (which we plan to merge in to base soon)
- if_wg now conforms to the WireGuard protocol and is more closely
aligned with security auditing guidelines
Note that the driver has been rebased away from using iflib. iflib
poses a number of challenges for a cloned device trying to operate in a
vnet that are non-trivial to solve and adds complexity to the
implementation for little gain.
The crypto implementation that was previously added to the tree was a
super complex integration of what previously appeared in an old out of
tree Linux module, which has been reduced to crypto.c containing simple
boring reference implementations. This is part of a near-to-mid term
goal to work with FreeBSD kernel crypto folks and take advantage of or
improve accelerated crypto already offered elsewhere.
There's additional test suite effort underway out-of-tree taking
advantage of the aforementioned jail-friendly semantics to test a number
of real-world topologies, based on netns.sh.
Also note that this is still a work in progress; work going further will
be much smaller in nature.
MFC after: 1 month (maybe)
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
P2P ifa may require 2 routes: one is the loopback route, another is
the "prefix" route towards its destination.
Current code marks loopback routes existence with IFA_RTSELF and
"prefix" p2p routes with IFA_ROUTE.
For historic reasons, we fill in ifa_dstaddr for loopback interfaces.
To avoid installing the same route twice, we preemptively set
IFA_RTSELF when adding "prefix" route for loopback.
However, the teardown part doesn't have this hack, so we try to
remove the same route twice.
Fix this by checking if ifa_dstaddr is different from the ifa_addr
and moving this logic into a separate function.
Reviewed By: kp
Differential Revision: https://reviews.freebsd.org/D29121
MFC after: 3 days
The current preference number were copied from IPv4 code,
assuming 500k routes to be the full-view. Adjust with the current
reality (100k full-view).
Reported by: Marek Zarychta <zarychtam at plan-b.pwste.edu.pl>
MFC after: 3 days
Introduce convenience macros to retrieve the DSCP, ECN or traffic class
bits from an IPv6 header.
Use them where appropriate.
Reviewed by: ae (previous version), rscheff, tuexen, rgrimes
MFC after: 2 weeks
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D29056
When tearing down vnet jails we can move an if_bridge out (as
part of the normal vnet_if_return()). This can, when it's clearing out
its list of member interfaces, change its link layer address.
That sends an iflladdr_event, but at that point we've already freed the
AF_INET/AF_INET6 if_afdata pointers.
In other words: when the iflladdr_event callbacks fire we can't assume
that ifp->if_afdata[AF_INET] will be set.
Reviewed by: donner@, melifaro@
MFC after: 1 week
Sponsored by: Orange Business Services
Differential Revision: https://reviews.freebsd.org/D28860
Currently ip6_input() calls in6ifa_ifwithaddr() for
every local packet, in order to check if the target ip
belongs to the local ifa in proper state and increase
its counters.
in6ifa_ifwithaddr() references found ifa.
With epoch changes, both `ip6_input()` and all other current callers
of `in6ifa_ifwithaddr()` do not need this reference
anymore, as epoch provides stability guarantee.
Given that, update `in6ifa_ifwithaddr()` to allow
it to return ifa without referencing it, while preserving
option for getting referenced ifa if so desired.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28648
in6_selectsrc() may call fib6_lookup() in some cases, which requires
epoch. Wrap in6_selectsrc* calls into epoch inside its users.
Mark it as requiring epoch by adding NET_EPOCH_ASSERT().
MFC after: 1 weeek
Differential Revision: https://reviews.freebsd.org/D28647
The only place where in6_ifawithifp() is used is ip6_output(),
which uses the returned ifa to bump traffic counters.
Given ifa stability guarantees is provided by epoch, do not refcount ifa.
This eliminates 2 atomic ops from IPv6 fast path.
Reviewed By: rstone
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28649
The lookup for a IPv6 multicast addresses corresponding to
the destination address in the datagram is protected by the
NET_EPOCH section. Access to each PCB is protected by INP_RLOCK
during comparing. But access to socket's so_options field is
not protected. And in some cases it is possible, that PCB
pointer is still valid, but inp_socket is not. The patch wides
lock holding to protect access to inp_socket. It copies locking
strategy from IPv4 UDP handling.
PR: 232192
Obtained from: Yandex LLC
MFC after: 3 days
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D28232
Historically receive buffer overflows have been ignored and programs
could not tell if they missed messages or messages had been truncated
because of overflows. Since programs historically do not expect to get
receive overflow errors, this behavior is not the default.
This is really really important for programs that use route(4) to keep in sync
with the system. If we loose a message then we need to reload the full system
state, otherwise the behaviour from that point is undefined and can lead
to chasing bogus bug reports.
Originally IFCAP_NOMAP meant that the mbuf has external storage pointer
that points to unmapped address. Then, this was extended to array of
such pointers. Then, such mbufs were augmented with header/trailer.
Basically, extended mbufs are extended, and set of features is subject
to change. The new name should be generic enough to avoid further
renaming.
we need to make sure that the m_nextpkt field is NULL
else the lower layers may do unwanted things.
Reviewed By: gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D28377
it gets unused.
Currently if_purgeifaddrs() uses in6_purgeaddr() to remove IPv6
ifaddrs. in6_purgeaddr() does not trrigger prefix removal if
number of linked ifas goes to 0, as this is a low-level function.
As a result, if_purgeifaddrs() purges all IPv4/IPv6 addresses but
keeps corresponding IPv6 prefixes.
Fix this by creating higher-level wrapper which handles unused
prefix usecase and use it in if_purgeifaddrs().
Differential revision: https://reviews.freebsd.org/D28128
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
Currently we create link-local route by creating an always-on IPv6 prefix
in the prefix list. This prefix is not tied to the link-local ifa.
This leads to the following problems:
First, when flushing interface addresses we skip on-link route, leaving
fe80::/64 prefix on the interface without any IPv6 addresses.
Second, when creating and removing link-local alias we lose fe80::/64 prefix
from the routing table.
Fix this by attaching link-local prefix to the ifa at the initial creation.
Reviewed by: hrs
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D28129
Relevant inet/inet6 code has the control over deciding what
the RIB lookup function currently is. With that in mind,
explicitly set it to the current value (rn_match) in the
datapath lookups. This avoids cost on indirect call.
Differential Revision: https://reviews.freebsd.org/D28066
Currently default behaviour is to keep only 1 packet per unresolved entry.
Ability to queue more than one packet was added 10 years ago, in r215207,
though the default value was kep intact.
Things have changed since that time. Systems tend to initiate multiple
connections at once for a variety of reasons.
For example, recent kern/252278 bug report describe happy-eyeball DNS
behaviour sending multiple requests to the DNS server.
The primary driver for upper value for the queue length determination is
memory consumption. Remote actors should not be able to easily exhaust
local memory by sending packets to unresolved arp/ND entries.
For now, bump value to 16 packets, to match Darwin implementation.
The proper approach would be to switch the limit to calculate memory
consumption instead of packet count and limit based on memory.
We should MFC this with a variation of D22447.
Reviewers: #manpages, #network, bz, emaste
Reviewed By: emaste, gbe(doc), jilles(doc)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D28068
This change introduces framework that allows to dynamically
attach or detach longest prefix match (lpm) lookup algorithms
to speed up datapath route tables lookups.
Framework takes care of handling initial synchronisation,
route subscription, nhop/nhop groups reference and indexing,
dataplane attachments and fib instance algorithm setup/teardown.
Framework features automatic algorithm selection, allowing for
picking the best matching algorithm on-the-fly based on the
amount of routes in the routing table.
Currently framework code is guarded under FIB_ALGO config option.
An idea is to enable it by default in the next couple of weeks.
The following algorithms are provided by default:
IPv4:
* bsearch4 (lockless binary search in a special IP array), tailored for
small-fib (<16 routes)
* radix4_lockless (lockless immutable radix, re-created on every rtable change),
tailored for small-fib (<1000 routes)
* radix4 (base system radix backend)
* dpdk_lpm4 (DPDK DIR24-8-based lookups), lockless datastrucure, optimized
for large-fib (D27412)
IPv6:
* radix6_lockless (lockless immutable radix, re-created on every rtable change),
tailed for small-fib (<1000 routes)
* radix6 (base system radix backend)
* dpdk_lpm6 (DPDK DIR24-8-based lookups), lockless datastrucure, optimized
for large-fib (D27412)
Performance changes:
Micro benchmarks (I7-7660U, single-core lookups, 2048k dst, code in D27604):
IPv4:
8 routes:
radix4: ~20mpps
radix4_lockless: ~24.8mpps
bsearch4: ~69mpps
dpdk_lpm4: ~67 mpps
700k routes:
radix4_lockless: 3.3mpps
dpdk_lpm4: 46mpps
IPv6:
8 routes:
radix6_lockless: ~20mpps
dpdk_lpm6: ~70mpps
100k routes:
radix6_lockless: 13.9mpps
dpdk_lpm6: 57mpps
Forwarding benchmarks:
+ 10-15% IPv4 forwarding performance (small-fib, bsearch4)
+ 25% IPv4 forwarding performance (full-view, dpdk_lpm4)
+ 20% IPv6 forwarding performance (full-view, dpdk_lpm6)
Control:
Framwork adds the following runtime sysctls:
List algos
* net.route.algo.inet.algo_list: bsearch4, radix4_lockless, radix4
* net.route.algo.inet6.algo_list: radix6_lockless, radix6, dpdk_lpm6
Debug level (7=LOG_DEBUG, per-route)
net.route.algo.debug_level: 5
Algo selection (currently only for fib 0):
net.route.algo.inet.algo: bsearch4
net.route.algo.inet6.algo: radix6_lockless
Support for manually changing algos in non-default fib will be added
soon. Some sysctl names will be changed in the near future.
Differential Revision: https://reviews.freebsd.org/D27401
In order to efficiently serve web traffic on a NUMA
machine, one must avoid as many NUMA domain crossings as
possible. With SO_REUSEPORT_LB, a number of workers can share a
listen socket. However, even if a worker sets affinity to a core
or set of cores on a NUMA domain, it will receive connections
associated with all NUMA domains in the system. This will lead to
cross-domain traffic when the server writes to the socket or
calls sendfile(), and memory is allocated on the server's local
NUMA node, but transmitted on the NUMA node associated with the
TCP connection. Similarly, when the server reads from the socket,
he will likely be reading memory allocated on the NUMA domain
associated with the TCP connection.
This change provides a new socket ioctl, TCP_REUSPORT_LB_NUMA. A
server can now tell the kernel to filter traffic so that only
incoming connections associated with the desired NUMA domain are
given to the server. (Of course, in the case where there are no
servers sharing the listen socket on some domain, then as a
fallback, traffic will be hashed as normal to all servers sharing
the listen socket regardless of domain). This allows a server to
deal only with traffic that is local to its NUMA domain, and
avoids cross-domain traffic in most cases.
This patch, and a corresponding small patch to nginx to use
TCP_REUSPORT_LB_NUMA allows us to serve 190Gb/s of kTLS encrypted
https media content from dual-socket Xeons with only 13% (as
measured by pcm.x) cross domain traffic on the memory controller.
Reviewed by: jhb, bz (earlier version), bcr (man page)
Tested by: gonzo
Sponsored by: Netfix
Differential Revision: https://reviews.freebsd.org/D21636
ROUTE_MPATH is the new config option controlling new multipath routing
implementation. Remove the last pieces of RADIX_MPATH-related code and
the config option.
Reviewed by: glebius
Differential Revision: https://reviews.freebsd.org/D27244
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
Enable ND6_IFF_IFDISABLED when the interface is created in the
kernel before return to user space.
This avoids a race when an interface is create by a program which
also calls ifconfig IF inet6 -ifdisabled and races with the
devd -> /etc/pccard_ether -> .. netif start IF -> ifdisabled
calls (the devd/rc framework disabling IPv6 again after the program
had enabled it already).
In case the global net.inet6.ip6.accept_rtadv was turned on,
we also default to enabling IPv6 on the interfaces, rather than
disabling them.
PR: 248172
Reported by: Gert Doering (gert greenie.muc.de)
Reviewed by: glebius (, phk)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D27324
* 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
When a user creates a TCP socket and tries to connect to the socket without
explicitly binding the socket to a local address, the connect call
implicitly chooses an appropriate local port. When evaluating candidate
local ports, the algorithm checks for conflicts with existing ports by
doing a lookup in the connection hash table.
In this circumstance, both the IPv4 and IPv6 code look for exact matches
in the hash table. However, the IPv4 code goes a step further and checks
whether the proposed 4-tuple will match wildcard (e.g. TCP "listen")
entries. The IPv6 code has no such check.
The missing wildcard check can cause problems when connecting to a local
server. It is possible that the algorithm will choose the same value for
the local port as the foreign port uses. This results in a connection with
identical source and destination addresses and ports. Changing the IPv6
code to align with the IPv4 code's behavior fixes this problem.
Reviewed by: tuexen
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D27164
Pad the icmp6stat structure so that we can add more counters in the
future without breaking compatibility again, last done in r358620.
Annotate the rarely executed error paths with __predict_false while
here.
Reviewed by: bz, melifaro
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26578
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
This adds a new IP_PROTO / IPV6_PROTO setsockopt (getsockopt)
option IP(V6)_VLAN_PCP, which can be set to -1 (interface
default), or explicitly to any priority between 0 and 7.
Note that for untagged traffic, explicitly adding a
priority will insert a special 801.1Q vlan header with
vlan ID = 0 to carry the priority setting
Reviewed by: gallatin, rrs
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D26409
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
* 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
