diff options
| author | Donatas Abraitis <donatas@opensourcerouting.org> | 2023-02-20 17:34:26 +0200 |
|---|---|---|
| committer | Donatas Abraitis <donatas@opensourcerouting.org> | 2023-03-21 13:19:44 +0200 |
| commit | 8eb09e64d205ccb24223be5de254167ec96f61b6 (patch) | |
| tree | 8039bb19077055703486c6ec046db5c48d4a8762 | |
| parent | c8cba1b88c952517ebe7f2ab2262a6ffb5499c0a (diff) | |
bgpd: Allow peering via 127.0.0.0/8
There are some specific edge-cases when is a need to run FRR and another FRR
and/or another BGP implementation on the same box. Relaxing 127.0.0.0/8 for
this case might be reasonable.
An example below peering via 127.0.0.0/8 between FRR and GoBGP:
```
% ss -ntlp | grep 179
LISTEN 0 4096 127.0.0.1:179 0.0.0.0:*
LISTEN 0 128 127.0.0.2:179 0.0.0.0:*
% grep 127.0.0.2 /etc/frr/daemons
bgpd_options=" -A 127.0.0.1 -l 127.0.0.2"
% grep local /etc/gobgp/config.toml
local-address-list = ["127.0.0.1"]
donatas-pc# sh ip bgp summary
IPv4 Unicast Summary (VRF default):
BGP router identifier 192.168.10.17, local AS number 65001 vrf-id 0
BGP table version 0
RIB entries 0, using 0 bytes of memory
Peers 1, using 725 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd PfxSnt Desc
127.0.0.1 4 65002 7 7 0 0 0 00:02:02 0 0 N/A
Total number of neighbors 1
donatas-pc#
```
Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
| -rw-r--r-- | bgpd/bgp_zebra.c | 7 | ||||
| -rw-r--r-- | doc/user/basic.rst | 4 | ||||
| -rw-r--r-- | lib/prefix.c | 2 | ||||
| -rw-r--r-- | lib/prefix.h | 5 |
4 files changed, 13 insertions, 5 deletions
diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c index da598993d1..346b3c90fd 100644 --- a/bgpd/bgp_zebra.c +++ b/bgpd/bgp_zebra.c @@ -834,6 +834,13 @@ bool bgp_zebra_nexthop_set(union sockunion *local, union sockunion *remote, peer->bgp->vrf_id); } + /* Handle peerings via loopbacks. For instance, peer between + * 127.0.0.1 and 127.0.0.2. In short, allow peering with self + * via 127.0.0.0/8. + */ + if (!ifp && cmd_allow_reserved_ranges_get()) + ifp = if_get_vrf_loopback(peer->bgp->vrf_id); + if (!ifp) { /* * BGP views do not currently get proper data diff --git a/doc/user/basic.rst b/doc/user/basic.rst index 254dad8303..337cfff937 100644 --- a/doc/user/basic.rst +++ b/doc/user/basic.rst @@ -349,6 +349,10 @@ Basic Config Commands Allow using IPv4 reserved (Class E) IP ranges for daemons. E.g.: setting IPv4 addresses for interfaces or allowing reserved ranges in BGP next-hops. + If you need multiple FRR instances (or FRR + any other daemon) running in a + single router and peering via 127.0.0.0/8, it's also possible to use this + knob if turned on. + Default: off. .. _sample-config-file: diff --git a/lib/prefix.c b/lib/prefix.c index a6aae08a6a..b8cad910f4 100644 --- a/lib/prefix.c +++ b/lib/prefix.c @@ -1399,7 +1399,7 @@ bool ipv4_unicast_valid(const struct in_addr *addr) if (IPV4_CLASS_D(ip)) return false; - if (IPV4_CLASS_E(ip)) { + if (IPV4_NET0(ip) || IPV4_NET127(ip) || IPV4_CLASS_E(ip)) { if (cmd_allow_reserved_ranges_get()) return true; else diff --git a/lib/prefix.h b/lib/prefix.h index 9c57283706..88a228b55c 100644 --- a/lib/prefix.h +++ b/lib/prefix.h @@ -499,11 +499,8 @@ extern int macstr2prefix_evpn(const char *str, struct prefix_evpn *p); /* NOTE: This routine expects the address argument in network byte order. */ static inline bool ipv4_martian(const struct in_addr *addr) { - in_addr_t ip = ntohl(addr->s_addr); - - if (IPV4_NET0(ip) || IPV4_NET127(ip) || !ipv4_unicast_valid(addr)) { + if (!ipv4_unicast_valid(addr)) return true; - } return false; } |