From 4f7e8c269dfb26ad8338aa118b6b7d504294821b Mon Sep 17 00:00:00 2001 From: Donatas Abraitis Date: Tue, 5 Nov 2024 15:51:58 +0200 Subject: bgpd: Reset BGP session only if it was a real BFD DOWN event Without this patch we always see a double-reset, e.g.: ``` 2024/11/04 12:42:43.010 BGP: [VQY9X-CQZKG] bgp_peer_bfd_update_source: address [0.0.0.0->172.18.0.3] to [172.18.0.2->172.18.0.3] 2024/11/04 12:42:43.010 BGP: [X8BD9-8RKN4] bgp_peer_bfd_update_source: interface none to eth0 2024/11/04 12:42:43.010 BFD: [MSVDW-Y8Z5Q] ptm-del-dest: deregister peer [mhop:no peer:172.18.0.3 local:0.0.0.0 vrf:default cbit:0x00 minimum-ttl:255] 2024/11/04 12:42:43.010 BFD: [NYF5K-SE3NS] ptm-del-session: [mhop:no peer:172.18.0.3 local:0.0.0.0 vrf:default] refcount=0 2024/11/04 12:42:43.010 BFD: [NW21R-MRYNT] session-delete: mhop:no peer:172.18.0.3 local:0.0.0.0 vrf:default 2024/11/04 12:42:43.010 BGP: [P3D3N-3277A] 172.18.0.3 [FSM] Timer (routeadv timer expire) 2024/11/04 12:42:43.010 BFD: [YA0Q5-C0BPV] control-packet: no session found [mhop:no peer:172.18.0.3 local:172.18.0.2 port:11] 2024/11/04 12:42:43.010 BFD: [MSVDW-Y8Z5Q] ptm-add-dest: register peer [mhop:no peer:172.18.0.3 local:172.18.0.2 vrf:default cbit:0x00 minimum-ttl:255] 2024/11/04 12:42:43.011 BFD: [PSB4R-8T1TJ] session-new: mhop:no peer:172.18.0.3 local:172.18.0.2 vrf:default ifname:eth0 2024/11/04 12:42:43.011 BGP: [Q4BCV-6FHZ5] zclient_bfd_session_update: 172.18.0.2/32 -> 172.18.0.3/32 (interface eth0) VRF default(0) (CPI bit no): Down 2024/11/04 12:42:43.011 BGP: [MKVHZ-7MS3V] bfd_session_status_update: neighbor 172.18.0.3 vrf default(0) bfd state Up -> Down 2024/11/04 12:42:43.011 BGP: [HZN6M-XRM1G] %NOTIFICATION: sent to neighbor 172.18.0.3 6/10 (Cease/BFD Down) 0 bytes 2024/11/04 12:42:43.011 BGP: [QFMSE-NPSNN] zclient_bfd_session_update: sessions updated: 1 2024/11/04 12:42:43.011 BGP: [ZWCSR-M7FG9] 172.18.0.3 [FSM] BGP_Stop (Established->Clearing), fd 22 ``` Reset is due to the source address change. With this patch, we reset the session only if it's a _REAL_ BFD down event, which means we trigger session reset if BFD session is established earlier than BGP. Signed-off-by: Donatas Abraitis --- bgpd/bgp_bfd.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/bgpd/bgp_bfd.c b/bgpd/bgp_bfd.c index 21864cf1a6..88ffb68206 100644 --- a/bgpd/bgp_bfd.c +++ b/bgpd/bgp_bfd.c @@ -53,14 +53,23 @@ static void bfd_session_status_update(struct bfd_session_params *bsp, peer->host); return; } - peer->last_reset = PEER_DOWN_BFD_DOWN; - /* rfc9384 */ - if (BGP_IS_VALID_STATE_FOR_NOTIF(peer->connection->status)) - bgp_notify_send(peer->connection, BGP_NOTIFY_CEASE, - BGP_NOTIFY_CEASE_BFD_DOWN); - - BGP_EVENT_ADD(peer->connection, BGP_Stop); + /* Once the BFD session is UP, and later BGP session is UP, + * BFD notices that peer->su_local changed, and BFD session goes down. + * We should trigger BGP session reset if BFD session is UP + * only when BGP session is UP already. + * Otherwise, we end up resetting BGP session when BFD session is UP, + * when the source address is changed, e.g. 0.0.0.0 -> 10.0.0.1. + */ + if (bss->last_event > peer->uptime) { + peer->last_reset = PEER_DOWN_BFD_DOWN; + /* rfc9384 */ + if (BGP_IS_VALID_STATE_FOR_NOTIF(peer->connection->status)) + bgp_notify_send(peer->connection, BGP_NOTIFY_CEASE, + BGP_NOTIFY_CEASE_BFD_DOWN); + + BGP_EVENT_ADD(peer->connection, BGP_Stop); + } } if (bss->state == BSS_UP && bss->previous_state != BSS_UP && -- cgit v1.2.3 From 5eb7047e2798e56c89c650434d3c6e7dc7533328 Mon Sep 17 00:00:00 2001 From: Donatas Abraitis Date: Tue, 12 Nov 2024 13:09:09 +0200 Subject: bgpd: Update source address for BFD session If BFD is down, we should try to detect the source automatically from the given interface. Signed-off-by: Donatas Abraitis --- bgpd/bgp_bfd.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/bgpd/bgp_bfd.c b/bgpd/bgp_bfd.c index 88ffb68206..3a1459b8a5 100644 --- a/bgpd/bgp_bfd.c +++ b/bgpd/bgp_bfd.c @@ -26,6 +26,7 @@ #include "bgpd/bgp_debug.h" #include "bgpd/bgp_vty.h" #include "bgpd/bgp_packet.h" +#include "bgpd/bgp_network.h" DEFINE_MTYPE_STATIC(BGPD, BFD_CONFIG, "BFD configuration data"); @@ -158,16 +159,33 @@ void bgp_peer_bfd_update_source(struct peer *p) struct in_addr v4; struct in6_addr v6; } src, dst; + struct interface *ifp; + union sockunion addr; /* Nothing to do for groups. */ if (CHECK_FLAG(p->sflags, PEER_STATUS_GROUP)) return; /* Figure out the correct source to use. */ - if (CHECK_FLAG(p->flags, PEER_FLAG_UPDATE_SOURCE) && p->update_source) - source = p->update_source; - else + if (CHECK_FLAG(p->flags, PEER_FLAG_UPDATE_SOURCE)) { + if (p->update_source) { + source = p->update_source; + } else if (p->update_if) { + ifp = if_lookup_by_name(p->update_if, p->bgp->vrf_id); + if (ifp) { + sockunion_init(&addr); + if (bgp_update_address(ifp, &p->connection->su, &addr)) { + if (BGP_DEBUG(bfd, BFD_LIB)) + zlog_debug("%s: can't find the source address for interface %s", + __func__, p->update_if); + } + + source = &addr; + } + } + } else { source = p->su_local; + } /* Update peer's source/destination addresses. */ bfd_sess_addresses(session, &family, &src.v6, &dst.v6); -- cgit v1.2.3 From d6c8c23635873ca26cd6837d2a8e0ad360a734c6 Mon Sep 17 00:00:00 2001 From: Donald Sharp Date: Wed, 20 Nov 2024 16:07:34 -0500 Subject: bgpd: Allow bfd to work if peer known but interface address not yet If bgp is coming up and bgp has not received the interface address yet but bgp has knowledge about a bfd peering, allow it to set the peering data appropriately. Signed-off-by: Donald Sharp --- bgpd/bgp_bfd.c | 8 ++++++-- bgpd/bgp_nexthop.c | 28 +++++++++++++++++----------- 2 files changed, 23 insertions(+), 13 deletions(-) diff --git a/bgpd/bgp_bfd.c b/bgpd/bgp_bfd.c index 3a1459b8a5..b3221853bb 100644 --- a/bgpd/bgp_bfd.c +++ b/bgpd/bgp_bfd.c @@ -151,8 +151,8 @@ void bgp_peer_config_apply(struct peer *p, struct peer_group *pg) void bgp_peer_bfd_update_source(struct peer *p) { - struct bfd_session_params *session = p->bfd_config->session; - const union sockunion *source; + struct bfd_session_params *session; + const union sockunion *source = NULL; bool changed = false; int family; union { @@ -162,6 +162,10 @@ void bgp_peer_bfd_update_source(struct peer *p) struct interface *ifp; union sockunion addr; + if (!p->bfd_config) + return; + + session = p->bfd_config->session; /* Nothing to do for groups. */ if (CHECK_FLAG(p->sflags, PEER_STATUS_GROUP)) return; diff --git a/bgpd/bgp_nexthop.c b/bgpd/bgp_nexthop.c index d12dc22330..508b3528c4 100644 --- a/bgpd/bgp_nexthop.c +++ b/bgpd/bgp_nexthop.c @@ -32,6 +32,7 @@ #include "bgpd/bgp_vty.h" #include "bgpd/bgp_rd.h" #include "bgpd/bgp_mplsvpn.h" +#include "bgpd/bgp_bfd.h" DEFINE_MTYPE_STATIC(BGPD, MARTIAN_STRING, "BGP Martian Addr Intf String"); @@ -409,17 +410,6 @@ void bgp_connected_add(struct bgp *bgp, struct connected *ifc) bgp_dest_set_bgp_connected_ref_info(dest, bc); } - for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) { - if (peer->conf_if && - (strcmp(peer->conf_if, ifc->ifp->name) == 0) && - !peer_established(peer->connection) && - !CHECK_FLAG(peer->flags, PEER_FLAG_IFPEER_V6ONLY)) { - connection = peer->connection; - if (peer_active(peer)) - BGP_EVENT_ADD(connection, BGP_Stop); - BGP_EVENT_ADD(connection, BGP_Start); - } - } } else if (addr->family == AF_INET6) { apply_mask_ipv6((struct prefix_ipv6 *)&p); @@ -443,6 +433,22 @@ void bgp_connected_add(struct bgp *bgp, struct connected *ifc) bgp_dest_set_bgp_connected_ref_info(dest, bc); } } + + /* + * Iterate over all the peers and attempt to set the bfd session + * data and if it's a bgp unnumbered get her flowing if necessary + */ + for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) { + bgp_peer_bfd_update_source(peer); + if (peer->conf_if && (strcmp(peer->conf_if, ifc->ifp->name) == 0) && + !peer_established(peer->connection) && + !CHECK_FLAG(peer->flags, PEER_FLAG_IFPEER_V6ONLY)) { + connection = peer->connection; + if (peer_active(peer)) + BGP_EVENT_ADD(connection, BGP_Stop); + BGP_EVENT_ADD(connection, BGP_Start); + } + } } void bgp_connected_delete(struct bgp *bgp, struct connected *ifc) -- cgit v1.2.3 From 2c92346292badda2bad93c1a1188d4349e38cde0 Mon Sep 17 00:00:00 2001 From: Donald Sharp Date: Thu, 5 Dec 2024 10:16:03 -0500 Subject: bgpd: When bgp notices a change to shared_network inform bfd of it When bgp is started up and reads the config in *before* it has received interface addresses from zebra, shared_network can be set to false in this case. Later on once bgp attempts to reconnect it will refigure out the shared_network again( because it has received the data from zebra now ). In this case tell bfd about it. Signed-off-by: Donald Sharp --- bgpd/bgp_zebra.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c index f9d096e6c6..e072e18c84 100644 --- a/bgpd/bgp_zebra.c +++ b/bgpd/bgp_zebra.c @@ -728,6 +728,7 @@ bool bgp_zebra_nexthop_set(union sockunion *local, union sockunion *remote, int ret = 0; struct interface *ifp = NULL; bool v6_ll_avail = true; + bool shared_network_original = peer->shared_network; memset(nexthop, 0, sizeof(struct bgp_nexthop)); @@ -892,6 +893,9 @@ bool bgp_zebra_nexthop_set(union sockunion *local, union sockunion *remote, peer->shared_network = 0; } + if (shared_network_original != peer->shared_network) + bgp_peer_bfd_update_source(peer); + /* KAME stack specific treatment. */ #ifdef KAME if (IN6_IS_ADDR_LINKLOCAL(&nexthop->v6_global) -- cgit v1.2.3 From c059cf388106f81040bdde3ff93a3b2cbd08523b Mon Sep 17 00:00:00 2001 From: Louis Scalbert Date: Wed, 22 Jan 2025 13:30:55 +0100 Subject: bgpd: fix bfd with update-source in peer-group Fix BFD session not created when the peer is in update-group with the update-source option. Signed-off-by: Louis Scalbert --- bgpd/bgp_bfd.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/bgpd/bgp_bfd.c b/bgpd/bgp_bfd.c index b3221853bb..f8f06df49f 100644 --- a/bgpd/bgp_bfd.c +++ b/bgpd/bgp_bfd.c @@ -114,6 +114,10 @@ void bgp_peer_config_apply(struct peer *p, struct peer_group *pg) */ gconfig = pg->conf; + if (CHECK_FLAG(gconfig->flags, PEER_FLAG_UPDATE_SOURCE) || + CHECK_FLAG(p->flags_override, PEER_FLAG_UPDATE_SOURCE)) + bgp_peer_bfd_update_source(p); + /* * If using default control plane independent configuration, * then prefer group's (e.g. it means it wasn't manually configured). -- cgit v1.2.3