Commit Graph

2109 Commits

Author SHA1 Message Date
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
7634919e15 Fix 'in6_purgeaddr: err=65, destination address delete failed' message.
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
2021-03-08 21:28:35 +00:00
Alexander V. Chernikov
d5be41beb7 Fix dpdk/ldradix fib lookup algorithm preference calculation.
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
2021-03-07 22:17:53 +00:00
Kristof Provost
bb4a7d94b9 net: Introduce IPV6_DSCP(), IPV6_ECN() and IPV6_TRAFFIC_CLASS() macros
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
2021-03-04 20:56:48 +01:00
Alexander V. Chernikov
cc3fa1e29f Fix crash with rtadv-originated multipath IPv6 routes.
PR:		253800
Reported by:	Frederic Denis <freebsdml at hecian.net>
MFC after:	immediately
2021-02-24 16:44:10 +00:00
Alexander V. Chernikov
9c4a8d24f0 Fix nd6 rib_action() handling.
rib_action() guarantees valid rc filling IFF it returns without error.
Check rib_action() return code instead of checking rc fields.

PR:		253800
Reported by:	Frederic Denis <freebsdml@hecian.net>
MFC after:	immediately
2021-02-23 22:40:01 +00:00
Kristof Provost
c139b3c19b arp/nd: Cope with late calls to iflladdr_event
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
2021-02-23 13:54:07 +01:00
Alexander V. Chernikov
8268d82cff Remove per-packet ifa refcounting from IPv6 fast path.
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
2021-02-15 22:33:12 +00:00
Alexander V. Chernikov
605284b894 Enforce net epoch in in6_selectsrc().
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
2021-02-15 22:33:12 +00:00
Alexander V. Chernikov
1bd44b11e5 Do not reference returned ifa in in6_ifawithifp().
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
2021-02-14 10:11:18 +00:00
Andrey V. Elsukov
3c782d9c91 [udp6] fix possible panic due to lack of locking.
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
2021-02-11 12:00:25 +03:00
Alexander V. Chernikov
924d1c9a05 Revert "SO_RERROR indicates that receive buffer overflows should be handled as errors."
Wrong version of the change was pushed inadvertenly.

This reverts commit 4a01b854ca.
2021-02-08 22:32:32 +00:00
Alexander V. Chernikov
4a01b854ca SO_RERROR indicates that receive buffer overflows should be handled as errors.
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.
2021-02-08 21:42:20 +00:00
Alexander V. Chernikov
91f2c69ec2 Fix unused-function waring when compiling with FIB_ALGO.
MFC after:	3 days
2021-01-30 23:25:56 +00:00
Gleb Smirnoff
3f43ada98c Catch up with 6edfd179c8: mechanically rename IFCAP_NOMAP to IFCAP_MEXTPG.
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.
2021-01-29 11:46:24 -08:00
Randall Stewart
24a8f6d369 When we are about to send down to the driver layer
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
2021-01-27 13:52:44 -05:00
Alexander V. Chernikov
f9e0752e35 Create new in6_purgeifaddr() which purges bound ifa prefix if
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
2021-01-17 20:32:25 +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
e58c8da068 Map IPv6 link-local prefix to the link-local ifa.
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
2021-01-13 10:03:15 +00:00
Alexander V. Chernikov
2defbe9f0e Use rn_match instead of doing indirect calls in fib_algo.
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
2021-01-11 23:30:35 +00:00
Alexander V. Chernikov
0da3f8c98d Bump amount of queued packets in for unresolved ARP/NDP entries to 16.
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
2021-01-11 19:51:11 +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
f5baf8bb12 Add modular fib lookup framework.
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
2020-12-25 11:33:17 +00:00
Andrew Gallatin
a034518ac8 Filter TCP connections to SO_REUSEPORT_LB listen sockets by NUMA domain
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
2020-12-19 22:04:46 +00:00
Hans Petter Selasky
ac4dd4cd95 Expose nonstandard IPv6 kernel definitions to standalone builds.
No functional change.

Reviewed by:	bz@
MFC after:	1 week
Sponsored by:	Mellanox Technologies // NVIDIA Networking
2020-12-04 21:51:47 +00:00
Alexander V. Chernikov
d1d941c5b9 Remove RADIX_MPATH config option.
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
2020-11-29 19:43:33 +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
Bjoern A. Zeeb
dd4d5a5ffb IPv6: set ifdisabled in the kernel rather than in rc
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
2020-11-25 20:58:01 +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
Jonathan T. Looney
440598dd9e Fix implicit automatic local port selection for IPv6 during connect calls.
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
2020-11-14 14:50:34 +00:00
Alexander V. Chernikov
d9999ae9ca Fix use-after-free in icmp6_notify_error().
Reported by:	Maxime Villard <max at m00nbsd.net>
Reviewed by:	markj
MFC after:	3 days
2020-10-28 20:22:20 +00:00
Mark Johnston
4caea9b169 icmp6: Count packets dropped due to an invalid hop limit
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
2020-10-19 17:07:19 +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
Richard Scheffenegger
868aabb470 Add IP(V6)_VLAN_PCP to set 802.1 priority per-flow.
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
2020-10-09 12:06:43 +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
1440f62266 Remove unused nhop_ref_any() function.
Remove "opt_mpath.h" header where not needed.

No functional changes.
2020-09-20 21:32:52 +00:00
Navdeep Parhar
b092fd6c97 if_vxlan(4): add support for hardware assisted checksumming, TSO, and RSS.
This lets a VXLAN pseudo-interface take advantage of hardware checksumming (tx
and rx), TSO, and RSS if the NIC is capable of performing these operations on
inner VXLAN traffic.

A VXLAN interface inherits the capabilities of its vxlandev interface if one is
specified or of the interface that hosts the vxlanlocal address. If other
interfaces will carry traffic for that VXLAN then they must have the same
hardware capabilities.

On transmit, if_vxlan verifies that the outbound interface has the required
capabilities and then translates the CSUM_ flags to their inner equivalents.
This tells the hardware ifnet that it needs to operate on the inner frame and
not the outer VXLAN headers.

An event is generated when a VXLAN ifnet starts. This allows hardware drivers to
configure their devices to expect VXLAN traffic on the specified incoming port.

On receive, the hardware does RSS and checksum verification on the inner frame.
if_vxlan now does a direct netisr dispatch to take full advantage of RSS. It is
not very clear why it didn't do this already.

Future work:
Rx: it should be possible to avoid the first trip up the protocol stack to get
the frame to if_vxlan just so it can decapsulate and requeue for a second trip
up the stack. The hardware NIC driver could directly call an if_vxlan receive
routine for VXLAN traffic instead.

Rx: LRO. depends on what happens with the previous item. There will have to to
be a mechanism to indicate that it's time for if_vxlan to flush its LRO state.

Reviewed by:	kib@
Relnotes:	Yes
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D25873
2020-09-18 02:37:57 +00:00
Navdeep Parhar
72cc43df17 Add a knob to allow zero UDP checksums for UDP/IPv6 traffic on the given UDP port.
This will be used by some upcoming changes to if_vxlan(4).  RFC 7348 (VXLAN)
says that the UDP checksum "SHOULD be transmitted as zero.  When a packet is
received with a UDP checksum of zero, it MUST be accepted for decapsulation."
But the original IPv6 RFCs did not allow zero UDP checksum.  RFC 6935 attempts
to resolve this.

Reviewed by:	kib@
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D25873
2020-09-18 02:21:15 +00:00
Mateusz Guzik
662c13053f net: clean up empty lines in .c and .h files 2020-09-01 21:19:14 +00:00
Kyle Evans
1e9b8db9b2 ipv6: quit dropping packets looping back on p2p interfaces
To paraphrase the below-referenced PR:

This logic originated in the KAME project, and was even controversial when
it was enabled there by default in 2001. No such equivalent logic exists in
the IPv4 stack, and it turns out that this leads to us dropping valid
traffic when the "point to point" interface is actually a 1:many tun
interface, e.g. with the wireguard userland stack.

Even in the case of true point-to-point links, this logic only avoids
transient looping of packets sent by misconfigured applications or
attackers, which can be subverted by proper route configuration rather than
hardcoded logic in the kernel to drop packets.

In the review, melifaro goes on to note that the kernel can't fix it, so it
perhaps shouldn't try to be 'smart' about it. Additionally, that TTL will
still kick in even with incorrect route configuration.

PR:		247718
Reviewed by:	melifaro, rgrimes
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D25567
2020-08-31 01:45:48 +00:00
Alexander V. Chernikov
a624ca3dff Move net/route/shared.h definitions to net/route/route_var.h.
No functional changes.

net/route/shared.h was created in the inital phases of nexthop conversion.
It was intended to serve the same purpose as route_var.h - share definitions
 of functions and structures between the routing subsystem components. At
 that time route_var.h was included by many files external to the routing
 subsystem, which largerly defeats its purpose.

As currently this is not the case anymore and amount of route_var.h includes
 is roughly the same as shared.h, retire the latter in favour of the former.
2020-08-28 22:50:20 +00:00
Alexander V. Chernikov
bec053ffe0 Make net.inet6.ip6.deembed_scopeid behaviour default & remove sysctl.
Submitted by: Neel Chauhan <neel AT neelc DOT org>
Differential Revision:	https://reviews.freebsd.org/D25637
2020-08-15 11:37:44 +00:00
Alexander V. Chernikov
2f23f45b20 Simplify dom_<rtattach|rtdetach>.
Remove unused arguments from dom_rtattach/dom_rtdetach functions and make
  them return/accept 'struct rib_head' instead of 'void **'.
Declare inet/inet6 implementations in the relevant _var.h headers similar
  to domifattach / domifdetach.
Add rib_subscribe_internal() function to accept subscriptions to the rnh
  directly.

Differential Revision:	https://reviews.freebsd.org/D26053
2020-08-14 21:29:56 +00:00
Hans Petter Selasky
b453d3d239 Use a static initializer for the multicast free tasks.
This makes the SYSINIT() function updated in r364072 superfluous.

Suggested by:	glebius@
MFC after:	1 week
Sponsored by:	Mellanox Technologies
2020-08-11 08:31:40 +00:00
Alexander V. Chernikov
9a00f6d067 Fix rib_subscribe() waitok flag by performing allocation outside epoch.
Make in6_inithead() use rib_subscribe with waitok to achieve reliable
 subscription allocation.

Reviewed by:	glebius
2020-08-11 07:05:30 +00:00
Bjoern A. Zeeb
f9461246a2 MC: add a note with reference to the discussion and history as-to why we
are where we are now.  The main thing is to try to get rid of the delayed
freeing to avoid blocking on the taskq when shutting down vnets.

X-Timeout:	if you still see this before 14-RELEASE remove it.
2020-08-10 10:58:43 +00:00
Hans Petter Selasky
3689652c65 Make sure the multicast release tasks are properly drained when
destroying a VNET or a network interface.

Else the inm release tasks, both IPv4 and IPv6 may cause a panic
accessing a freed VNET or network interface.

Reviewed by:		jmg@
Discussed with:		bz@
Differential Revision:	https://reviews.freebsd.org/D24914
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2020-08-10 10:46:08 +00:00
Hans Petter Selasky
a95ef9d38d Use proper prototype for SYSINIT() functions.
Mark the unused argument using the __unused macro.

Discussed with:		kib@
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2020-08-10 10:40:19 +00:00
Bjoern A. Zeeb
a9839c4aee IPV6_PKTINFO support for v4-mapped IPv6 sockets
When using v4-mapped IPv6 sockets with IPV6_PKTINFO we do not
respect the given v4-mapped src address on the IPv4 socket.
Implement the needed functionality. This allows single-socket
UDP applications (such as OpenVPN) to work better on FreeBSD.

Requested by:	Gert Doering (gert greenie.net), pfsense
Tested by:	Gert Doering (gert greenie.net)
Reviewed by:	melifaro
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D24135
2020-08-07 15:13:53 +00:00