bgp_attr_intern(attr) takes an attribute, duplicates it, and inserts it
into the attribute hash table, returning the inserted attr. This is done
when processing a bgp update. We store the returned attribute in the
path info struct. However, later on we modify one of the fields of the
attribute. This field is inspected by attrhash_cmp, the function that
allows the hash table to select the correct item from the hash chain for
a given key when doing a lookup on an item. By modifying the field after
it's been inserted, we open the possibility that two items in the same
chain that at insertion time were differential by attrhash_cmp becomes
equal according to that function. When performing subsequent hash
lookups, it is then indeterminate which of the equivalent items the hash
table will select from the chain (in practice it is the first one but
this may not be the one we want). Thus, it is illegal to modify
data used by a hash comparison function after inserting that data into
a hash table.
In fact this is occurring for attributes. We insert two attributes that
hash to the same key and thus end up in the same hash chain. Then we
modify one of them such that the two items now compare equal. Later one
we want to release the second item from the chain before XFREE()'ing it,
but since the two items compare equal we get the first item back, then
free the second one, which constitutes two bugs, the first being the
wrong attribute removed from the hash table and the second being a
dangling pointer stored in the hash table.
To rectify this we need to perform any modifications to an attr before
it is inserted into the table, i.e., before calling bgp_attr_intern().
This patch does that by moving the sole modification to the attr that
occurs after the insert (that I have seen) before that call.
Signed-off-by: Quentin Young <qlyoung@nvidia.com>
This will check route-maps as well, not only prefix-lists, access-lists, and
filter-lists.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
until now, the assumption was done in bgp flowspec code that the
information contained was an ipv4 flowspec prefix. now that it is
possible to handle ipv4 or ipv6 flowspec prefixes, that information is
stored in prefix_flowspec attribute. Also, some unlocking is done in
order to process ipv4 and ipv6 flowspec entries.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
When a SYNC route i.e. a route with a local ES as destination is
rxed on a switch (say L11) from an ES peer (say L12) a local
MAC/neigh entry is created on L11 with the local access port
as dest port.
Creation of the local entry triggers a local path advertisement from
L11. This could be a "locally-active" path or a "locally-inactive"
path. Inactive paths are advertised with the proxy bit.
To ensure that the local entry is not deleted by a SYNC route it is
given absolute precedence over peer-paths.
If there are two non-local paths with the same dest ES and same MM
seq number the non-proxy path is preferred. This is done to ensure
that we don't lose track of the peer-activity.
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
1. Sample ES display
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
torm-11# sh bgp l2vpn evpn es
ES Flags: L local, R remote, I inconsistent
VTEP Flags: E ESR/Type-4, A active nexthop
ESI Flags RD #VNIs VTEPs
03:00:00:00:00:01:11:00:00:01 LR 27.0.0.15:15 10 27.0.0.16(EA)
03:00:00:00:00:01:22:00:00:02 LR 27.0.0.15:16 10 27.0.0.16(EA)
03:00:00:00:00:01:22:00:00:03 LR 27.0.0.15:17 10 27.0.0.16(EA)
03:00:00:00:00:02:11:00:00:01 R - 10 27.0.0.17(A),27.0.0.18(A)
03:00:00:00:00:02:22:00:00:02 R - 10 27.0.0.17(A),27.0.0.18(A)
03:00:00:00:00:02:22:00:00:03 R - 10 27.0.0.17(A),27.0.0.18(A)
torm-11#
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
2. Sample ES-EVI display
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
torm-11# sh bgp l2vpn evpn es-evi
Flags: L local, R remote, I inconsistent
VTEP-Flags: E EAD-per-ES, V EAD-per-EVI
VNI ESI Flags VTEPs
1005 03:00:00:00:00:01:11:00:00:01 LR 27.0.0.16(EV)
1005 03:00:00:00:00:01:22:00:00:02 LR 27.0.0.16(EV)
1005 03:00:00:00:00:01:22:00:00:03 LR 27.0.0.16(EV)
1005 03:00:00:00:00:02:11:00:00:01 R 27.0.0.17(EV),27.0.0.18(EV)
1005 03:00:00:00:00:02:22:00:00:02 R 27.0.0.17(EV),27.0.0.18(EV)
1005 03:00:00:00:00:02:22:00:00:03 R 27.0.0.17(EV),27.0.0.18(EV)
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
3. Sample EAD route display
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
torm-11# sh bgp l2vpn evpn route type ead
BGP table version is 19, local router ID is 27.0.0.15
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
EVPN type-1 prefix: [4]:[ESI]:[EthTag]:[IPlen]:[VTEP-IP]
EVPN type-2 prefix: [2]:[EthTag]:[MAClen]:[MAC]:[IPlen]:[IP]
EVPN type-3 prefix: [3]:[EthTag]:[IPlen]:[OrigIP]
EVPN type-4 prefix: [4]:[ESI]:[IPlen]:[OrigIP]
EVPN type-5 prefix: [5]:[EthTag]:[IPlen]:[IP]
Network Next Hop Metric LocPrf Weight Path
Extended Community
Route Distinguisher: 27.0.0.15:5
*> [1]:[0]:[03:00:00:00:00:01:11:00:00:01]:[128]:[0.0.0.0]
27.0.0.15 32768 i
ET:8 RT:5550:1009
*> [1]:[0]:[03:00:00:00:00:01:22:00:00:02]:[128]:[0.0.0.0]
27.0.0.15 32768 i
ET:8 RT:5550:1009
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Add ESI as an inline attribute field along with the other EVPN
attributes. This may be re-worked when the rest of the EVPN
attributes find a new home.
Some cleanup has been done to get rid of stale/unused references
to ESI. And also to consolidate duplicate definitions of ES ID
types.
Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
When we have a prefix that has been selected, note that that
particular flag has been set and give that information to the
end user.
eva# show bgp ipv4 uni neighbors 192.168.161.131 prefix-counts
Prefix counts for 192.168.161.131, IPv4 Unicast
PfxCt: 814246
Counts from RIB table walk:
Adj-in: 0
Damped: 0
Removed: 0
History: 0
Stale: 0
Valid: 814246
All RIB: 814246
PfxCt counted: 814246
PfxCt Best Selected: 0
Useable: 814246
eva# show bgp ipv4 uni neighbors 192.168.161.2 prefix-counts
Prefix counts for 192.168.161.2, IPv4 Unicast
PfxCt: 814070
Counts from RIB table walk:
Adj-in: 0
Damped: 0
Removed: 0
History: 0
Stale: 0
Valid: 814070
All RIB: 814070
PfxCt counted: 814070
PfxCt Best Selected: 814070
Useable: 814070
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
If _force_ is set, then ALL prefixes are counted for maximum instead of
accepted only. This is useful for cases where an inbound filter is applied,
but you want maximum-prefix to act on ALL (including filtered) prefixes.
For instance, we have a configuration like:
neighbor r1 maximum-prefix 10
neighbor r1 prefix-list custom in
!
ip prefix-list custom seq 1 permit 10.0.0.0/24
ip prefix-list custom seq 2 permit 10.0.1.0/24
This will accept only 2 prefixes and discard all others instead of
shutting down the session when 10 is reached.
With this new knob (force), we will count all received prefixes and shutdown
the session when 10 is reached.
The bigger problem is when you have lots of peers with full feed and such a
configuration like in an example.
This is kinda re-ordering of how to treat filter vs. maximum-prefix.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
```
(gdb) bt
0 0x00007f45a6f0a781 in raise () from /lib/x86_64-linux-gnu/libc.so.6
1 0x00007f45a6ef455b in abort () from /lib/x86_64-linux-gnu/libc.so.6
2 0x00007f45a7781920 in core_handler (signo=11, siginfo=0x7fffac7b84b0, context=<optimized out>) at lib/sigevent.c:228
3 <signal handler called>
4 0x000055a4133c0f32 in bgp_table_stats (vty=vty@entry=0x55a415acb240, bgp=0x0, afi=AFI_IP, safi=SAFI_UNICAST, json_array=json_array@entry=0x0) at bgpd/bgp_route.c:11412
5 0x000055a4133c13fb in show_ip_bgp_afi_safi_statistics (self=<optimized out>, vty=0x55a415acb240, argc=6, argv=<optimized out>) at bgpd/bgp_route.c:10749
6 0x00007f45a773917d in cmd_execute_command_real (vline=vline@entry=0x55a415ab7e10, vty=vty@entry=0x55a415acb240, cmd=cmd@entry=0x0, filter=FILTER_RELAXED)
at lib/command.c:909
7 0x00007f45a773afdf in cmd_execute_command (vline=vline@entry=0x55a415ab7e10, vty=vty@entry=0x55a415acb240, cmd=0x0, vtysh=vtysh@entry=0) at lib/command.c:968
8 0x00007f45a773b135 in cmd_execute (vty=vty@entry=0x55a415acb240, cmd=cmd@entry=0x55a415ace950 "show ip bgp vrf all statistics", matched=matched@entry=0x0,
vtysh=vtysh@entry=0) at lib/command.c:1122
9 0x00007f45a7794d62 in vty_command (vty=vty@entry=0x55a415acb240, buf=0x55a415ace950 "show ip bgp vrf all statistics") at lib/vty.c:526
10 0x00007f45a7794fb6 in vty_execute (vty=vty@entry=0x55a415acb240) at lib/vty.c:1293
11 0x00007f45a7797804 in vtysh_read (thread=<optimized out>) at lib/vty.c:2126
12 0x00007f45a778f641 in thread_call (thread=thread@entry=0x7fffac7bb040) at lib/thread.c:1550
13 0x00007f45a775b6d8 in frr_run (master=0x55a415542820) at lib/libfrr.c:1098
14 0x000055a4133815d6 in main (argc=10, argv=0x7fffac7bb2a8) at bgpd/bgp_main.c:509
```
"show ip bgp vrf all statistics" should show statistics for all VRFs if "all"
is specified.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Remove mid-string line breaks, cf. workflow doc:
.. [#tool_style_conflicts] For example, lines over 80 characters are allowed
for text strings to make it possible to search the code for them: please
see `Linux kernel style (breaking long lines and strings)
<https://www.kernel.org/doc/html/v4.10/process/coding-style.html#breaking-long-lines-and-strings>`_
and `Issue #1794 <https://github.com/FRRouting/frr/issues/1794>`_.
Scripted commit, idempotent to running:
```
python3 tools/stringmangle.py --unwrap `git ls-files | egrep '\.[ch]$'`
```
Signed-off-by: David Lamparter <equinox@diac24.net>
It's hard to cope with cases when next-hop is changed/unchanged or
peers are non-direct.
It would be better to show the hostname and nexthop IP address (both)
under `show bgp` to quickly identify the source and the real next-hop
of the route.
If `bgp default show-nexthop-hostname` is toggled the output looks like:
```
spine1-debian-9# show bgp
BGP table version is 1, local router ID is 2.2.2.2, vrf id 0
Default local pref 100, local AS 65002
Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,
i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* 2a02:4780::/64 fe80::a00:27ff:fe09:f8a3(exit1-debian-9)
0 0 65001 ?
spine1-debian-9# show ip bgp
BGP table version is 5, local router ID is 2.2.2.2, vrf id 0
Default local pref 100, local AS 65002
Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,
i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.255.255.0/24 192.168.0.1(exit1-debian-9)
0 0 65001 ?
```
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
If the RT changes on a L3VPN route then any leak of this route into
a VRF should be withdrawn.
Extend existing EVPN check for RT change to cover L3VPN routes.
Signed-off-by: Pat Ruddy <pat@voltanet.io>
This is the bulk part extracted from "bgpd: Convert from `struct
bgp_node` to `struct bgp_dest`". It should not result in any functional
change.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
If we have something like:
```
ip route 1.1.1.0/24 Null0
!
router bgp 100
no bgp ebgp-requires-policy
neighbor 192.168.0.2 remote-as 200
!
address-family ipv4 unicast
network 1.1.1.0/24
redistribute connected
exit-address-family
!
line vty
!
```
1.1.1.0/24 is not advertised due to martian nexthop (0.0.0.0). It starts
working only when we use `redistribute static`.
By checking if it's a BGP static route we able to announce
1.1.1.0/24 with `network 1.1.1.0/24` without redistribute even when
`bgp import-check` is enabled.
Disabling `bgp import-check` works as well, but it's enabled by default
since 7.4.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Non-best paths (path info structures) also need to be freed during
table cleanup not only to release their memory but to also ensure
any linkages are updated correctly. One such example is for EVPN
where there is a link between the imported path info (in a L2 or
L3 vrf instance) and its parent path info.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Without specifying a default afi/safi we get a segfault:
```
(gdb) frame 4
bgp_table_stats (..., afi=32724, safi=SAFI_UNICAST, ...
11349 if (!bgp->rib[afi][safi]) {
(gdb)
```
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
unicast and labeled-unicast share the same table, but configuration should
be visible for both independently. Without this fix it confuses a bit
because when you enter `network 10.0.0.0/24` under labeled-unicast it's
written in unicast family block.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Replace sprintf with snprintf where straightforward to do so.
- sprintf's into local scope buffers of known size are replaced with the
equivalent snprintf call
- snprintf's into local scope buffers of known size that use the buffer
size expression now use sizeof(buffer)
- sprintf(buf + strlen(buf), ...) replaced with snprintf() into temp
buffer followed by strlcat
Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>
When we receive an UPDATE with MP_NEXTHOP len as 32 bytes, we shouldn't
check if the global (1st) nexthop is unspecified.
Peering between bird and FRRouting we receive from Bird something like:
```
rcvd UPDATE w/ attr: , origin i, mp_nexthop ::(fe80::a00:27ff:fe09:f8a3)
```
The link-local (2nd) nexthop is valid and validated later in the code.
Before it was marked:
```
IPv6 unicast -- DENIED due to: martian or self next-hop;
```
After it's a valid prefix:
```
spine1-debian-9# show bgp
BGP table version is 0, local router ID is 2.2.2.2, vrf id 0
Default local pref 100, local AS 65002
Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,
i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
2a02:4780::/64 fe80::a00:27ff:fe09:f8a3
0 65001 i
Displayed 1 routes and 1 total paths
```
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
In real world sometimes happens that bgp_nexthop_cache is NULL. Avoid
segfaulting when using `show [ip] bgp ...` CLI commands.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
The problem is when using kinda such topologies:
(192.168.1.1/32) r1 <-- eBGP --> r2 <-- iBGP --> r3
Looking at r3's nexthop for 192.168.1.1/32 we have it as r2, but really
it MUST be r1.
Checking if the nexthop is connected solves the problem even for cases
when route-reflectors are used.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Some competitive vendors like Cisco, Bird, OpenBGPD,
Nokia already have this by default enabled.
The list is here: https://github.com/bgp/RFC8212
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Problem Description:
=====================
+--+ +--+
|R1|-(192.201.202.1)----iBGP----(192.201.202.2)-|R2|
+--+ +--+
Routes on R2:
=============
S>* 202.202.202.202/32 [1/0] via 192.201.78.1, ens256, 00:40:48
Where, the next-hop network, 192.201.78.0/24, is a directly connected network address.
C>* 192.201.78.0/24 is directly connected, ens256, 00:40:48
Configurations on R1:
=====================
!
router bgp 201
bgp router-id 192.168.0.1
neighbor 192.201.202.2 remote-as 201
!
Configurations on R2:
=====================
!
ip route 202.202.202.202/32 192.201.78.1
!
router bgp 201
bgp router-id 192.168.0.2
neighbor 192.201.202.1 remote-as 201
!
address-family ipv4 unicast
redistribute static
exit-address-family
!
Step-1:
=======
R1 receives the route 202.202.202.202/32 from R2.
R1 installs the route in its BGP RIB.
Step-2:
=======
On R1, a connected interface address is added.
The address is the same as the next-hop of the BGP route received from R2 (192.201.78.1).
Point of Failure:
=================
R1 resolves the BGP route even though the route's next-hop is its own connected address.
Even though this appears to be a misconfiguration it would still be better to safeguard the code against it.
Fix:
====
When BGP receives a connected route from Zebra, it processes the
routes for the next-hop update.
While doing so, BGP must ignore routes whose next-hop address matches
the address of the connected route for which Zebra sent the next-hop update
message.
Signed-off-by: NaveenThanikachalam <nthanikachal@vmware.com>
Ensure that upon a link-bandwidth change - for e.g., due to change in
the number of multipaths - EVPN type-5 route injection is triggered.
In the absence of this, the proper link-bandwidth is not updated in
EVPN type-5 routes originated by the router.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
take into account polychaeta tips ono code style.
also, take into account miscellaneous code style recommandations like
braces usage.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
This macro is undefined if vnc is disabled, and while it defaults to 0,
this is still wrong and causes issues with -Werror
Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>
- each statistics is encapsulated into concatenated "<afi><safi>" value.
- the json encoding for floating and double values is using json api
double api. this change is done for bgp statistics.
- the lines over 80 characters have been handled.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
this command is a shortcut to facilitate the extraction of statistics
for all afi/safi related to one bgp instance.
the command is: show bgp [vrf XX] statistics-all [json]
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
safis that use a route distinguisher in bgp tables, and as such
introduce a two level hierarchy on the bgp table, must be made available
to statistics too.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
add json support for show bgp statistics command.
The title of the stats entry is aggregated without spaces.
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
Support configurable options to control how link bandwidth is handled
by the receiver. The default behavior is to automatically honor the
link bandwidths received and use it to perform a weighted ECMP BUT only
if all paths in the multipath have associated link bandwidth; if one or
more paths do not have link bandwidth, normal ECMP is performed among
the multipaths. This behavior is as recommended by
https://tools.ietf.org/html/draft-ietf-idr-link-bandwidth.
The additional options available are to (a) completely ignore any link
bandwidth (i.e., weighted ECMP is effectively disabled), (b) skip paths
in the multipath which do not have link bandwidth and perform weighted
ECMP among the other paths (if at least some paths have the bandwidth)
or (c) use a default weight (value chosen is 1) for the paths which
do not have link bandwidth.
The command syntax is
bgp bestpath bandwidth <ignore|skip-missing|default-weight-for-missing>
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
When announcing ourselves as the next hop (e.g., to EBGP peers), if the
best path has the link bandwidth extended community and it is transitive,
change the value of the link bandwidth to the cumulative downstream
bandwidth (sum of the link bandwidths of all our multipaths) as this
makes the most sense. It is also implied by
https://tools.ietf.org/html/draft-mohanty-bess-ebgp-dmz. Of course, do
not override the link bandwidth if it has been specified by policy.
Note: Transitive extended communities will be automatically passed along
to EBGP peers; this commit is updating the value that is announced to
something that is the most appropriate.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Don Slice <dslice@cumulusnetworks.com>
Implement the code to handle the other route-map options to generate
the link bandwidth, namely, to use the cumulative bandwidth or to
base this on the number of multipaths. In the latter case, a reference
bandwidth is internally chosen - the implementation uses a value of
1 Gbps.
These additional options mean that the prefix may need to be advertised
if there is a link bandwidth change, which is a new criteria. Define a
new path (change) flag to support this and implement the advertisement.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Don Slice <dslice@cumulusnetworks.com>
Add new function `bgp_node_get_prefix()` and modify
the bgp code base to use it.
This is prep work for the struct bgp_dest rework.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Show if this malformed under `show [ip] bgp <prefix>`:
```
eva# sh ip bgp 103.79.124.0/22
BGP routing table entry for 103.79.124.0/22
Paths: (1 available, best #1, table default)
Advertised to non peer-group peers:
192.168.201.136
64539 15096 6939 7545 7545 136001, (aggregated by 0(malformed) 0.0.0.0)
192.168.201.136 from 192.168.201.136 (192.168.201.136)
Origin IGP, valid, external, best (First path received)
Last update: Thu Mar 26 10:02:07 2020
```
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Line break at the end of the message is implicit for zlog_* and flog_*,
don't put it in the string. Mid-message line breaks are currently
unsupported. (LF is "end of message" in syslog.)
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Modify code to use lookup function agg_node_get_prefix()
as the abstraction layer. When we rework bgp_node to
bgp_dest this will allow us to greatly limit the amount
of work needed to do that.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Future work needs the ability to specify a
const struct prefix value. Iterate into
bgp a bit to get this started.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Defer the grabbing of the prefix for as long as is possible.
This is a long term rework of how we access the `struct bgp_node`
to only use accessor functions.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Modify more code to use `const struct prefix` throughout
bgp. This is all prep work for adding an accessor function
for bgp_node to get the prefix and reduce all the places that
code needs to be touched when we get that work done.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Some were converted to bool, where true/false status is needed.
Converted to void only those, where the return status was only false or true.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Ensure that the EVPN advertise route-map is applied on a copy of the
original path_info and associated attribute, so that if the route-map
has SET clauses, they can operate properly. This closely follows
the model already in use in other route-map application code.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Don Slice <dslice@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
A BGP update-group is dynamically created to group together a set of peers
such that any BGP updates can be formed just once for the entire group and
only the next hop attribute may need to be modified when the update is sent
out to each peer in the group. The update formation code attempts to
determine as much as possible if the next hop will be set to our own IP
address for every peer in the group. This helps to avoid additional checks
at the point of sending the update (which happens on a per-peer basis) and
also because some other attributes may/could vary depending on whether the
next hop is set to our own IP or not. Resetting the next hop to our own IP
address is the most common behavior for EBGP peerings in the absence of
other user-configured or internal (e.g., for l2vpn/evpn) settings and
peerings on a shared subnet.
The code had a flaw in the multiaccess check to see if there are peers in
the update group which are on a shared subnet as the next hop of the path
being announced - the source peer could itself be in the same update group
and cause the check to give an incorrect result. Modify the check to skip
the source peer so that the check is more accurate.
Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Don Slice <dslice@cumulusnetworks.com>
The bgp reason code was being reset in bgp_best_selection
by rerunning bgp_path_info_cmp multiple times under certain
receiving patterns of data from peers.
This is the debugs that show this issue:
2020/03/16 19:17:22.523780 BGP: 2001:20:1:1::6 rcvd UPDATE w/ attr: nexthop 20.1.1.6, origin i, metric 600, community 1000:1006, path 20
2020/03/16 19:17:22.523819 BGP: 2001:20:1:1::6 rcvd 20.10.0.6/32 IPv4 unicast
2020/03/16 19:17:22.556168 BGP: 20.1.1.6 rcvd UPDATE w/ attr: nexthop 20.1.1.6, origin i, metric 500, community 1000:1006, path 20
2020/03/16 19:17:22.556209 BGP: 20.1.1.6 rcvd 20.10.0.6/32 IPv4 unicast
2020/03/16 19:17:22.572358 BGP: bgp_process_main_one: p=20.10.0.6/32 afi=IPv4, safi=unicast start
2020/03/16 19:17:22.572408 BGP: 20.10.0.6/32: Comparing path 2001:20:1:1::6 flags 0x410 with path 20.1.1.6 flags 0x410
2020/03/16 19:17:22.572415 BGP: 20.10.0.6/32: path 2001:20:1:1::6 loses to path 20.1.1.6 due to MED 600 > 500
2020/03/16 19:17:22.572422 BGP: 20.10.0.6/32: path 20.1.1.6 is the bestpath from AS 20
2020/03/16 19:17:22.572429 BGP: 20.10.0.6/32: path 20.1.1.6 is the initial bestpath
2020/03/16 19:17:22.572435 BGP: bgp_best_selection: pi 0x5627187c66c0 dmed
2020/03/16 19:17:22.572441 BGP: 20.10.0.6/32: After path selection, newbest is path 20.1.1.6 oldbest was NONE
2020/03/16 19:17:22.572447 BGP: 20.10.0.6/32: path 20.1.1.6 is the bestpath, add to the multipath list
2020/03/16 19:17:22.572453 BGP: 20.10.0.6/32: path 2001:20:1:1::6 has the same nexthop as the bestpath, skip it
2020/03/16 19:17:22.572460 BGP: 20.10.0.6/32: starting mpath update, newbest 20.1.1.6 num candidates 1 old-mpath-count 0 old-cum-bw u0
2020/03/16 19:17:22.572466 BGP: 20.10.0.6/32: comparing candidate 20.1.1.6 with existing mpath NONE
2020/03/16 19:17:22.572473 BGP: 20.10.0.6/32: New mpath count (incl newbest) 1 mpath-change NO all_paths_lb 0 cum_bw u0
Effectively if BGP receives 2 paths it could end up running bgp_path_info_cmp multiple times
and in some situations overwrite the reason selected the first time through.
In this example path selection is run and the MED is the reason for the choice.
Then in bgp_best_selection is run again this time clearing new_select
to NULL before calling path selection for the first time. This second
call into path selection resets the reason, since it is only passing in one
path. So save the last reason selected and restore in this case.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
