From 9b937497ca7992998e2b8af485ca889d75b40f55 Mon Sep 17 00:00:00 2001 From: nkelapur Date: Tue, 18 Jan 2022 09:10:50 +0530 Subject: [PATCH] Fix IPv4 routes with IPv6 link local next hops installed in FPM (#8740) * Description: Currently IPv4 routes with IPv6 link local next hops are not properly installed in FPM. Reason is the netlink decoding truncates the ipv6 LL address to 4 byte ipv4 address. Ex : fe80:: is directly converted to ipv4 and it results in 254.128.0.0 as next hop for below routes show ip route Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP, T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP, F - PBR, f - OpenFabric, > - selected route, * - FIB route, q - queued, r - rejected, b - backup B>* 2.1.0.0/16 [200/0] via fe80::268a:7ff:fed0:d40, Ethernet0, weight 1, 02:22:26 B>* 5.1.0.0/16 [200/0] via fe80::268a:7ff:fed0:d40, Ethernet0, weight 1, 02:22:26 B>* 10.1.0.2/32 [200/0] via fe80::268a:7ff:fed0:d40, Ethernet0, weight 1, 02:22:26 Hence this fix converts the ipv6-LL address to ipv4-LL (169.254.0.1) address before sending it to FPM. This is inline with how these types of routes are currently programmed into kernel. Signed-off-by: Nikhil Kelapure --- ...-address-for-Ipv6-linl-local-nexthop.patch | 55 +++++++++++++++++++ src/sonic-frr/patch/series | 1 + 2 files changed, 56 insertions(+) create mode 100644 src/sonic-frr/patch/0011-Ipv4-Link-local-address-for-Ipv6-linl-local-nexthop.patch diff --git a/src/sonic-frr/patch/0011-Ipv4-Link-local-address-for-Ipv6-linl-local-nexthop.patch b/src/sonic-frr/patch/0011-Ipv4-Link-local-address-for-Ipv6-linl-local-nexthop.patch new file mode 100644 index 0000000000..7a041c02fe --- /dev/null +++ b/src/sonic-frr/patch/0011-Ipv4-Link-local-address-for-Ipv6-linl-local-nexthop.patch @@ -0,0 +1,55 @@ +diff --git a/zebra/zebra_fpm.c b/zebra/zebra_fpm.c +index 7b0611bf9..b5582ea35 100644 +--- a/zebra/zebra_fpm.c ++++ b/zebra/zebra_fpm.c +@@ -288,6 +288,9 @@ static void zfpm_start_connect_timer(const char *reason); + static void zfpm_start_stats_timer(void); + static void zfpm_mac_info_del(struct fpm_mac_info_t *fpm_mac); + ++static const char ipv4_ll_buf[16] = "169.254.0.1"; ++union g_addr ipv4ll_gateway; ++ + /* + * zfpm_thread_should_yield + */ +@@ -1988,6 +1991,9 @@ static int zfpm_init(struct thread_master *master) + zfpm_stats_init(&zfpm_g->last_ivl_stats); + zfpm_stats_init(&zfpm_g->cumulative_stats); + ++ memset(&ipv4ll_gateway, 0, sizeof(ipv4ll_gateway)); ++ inet_pton(AF_INET, ipv4_ll_buf, &ipv4ll_gateway.ipv4); ++ + install_node(&zebra_node); + install_element(ENABLE_NODE, &show_zebra_fpm_stats_cmd); + install_element(ENABLE_NODE, &clear_zebra_fpm_stats_cmd); +diff --git a/zebra/zebra_fpm_netlink.c b/zebra/zebra_fpm_netlink.c +index 60ea7f97e..0f8ba5413 100644 +--- a/zebra/zebra_fpm_netlink.c ++++ b/zebra/zebra_fpm_netlink.c +@@ -221,7 +221,12 @@ static int netlink_route_info_add_nh(struct netlink_route_info *ri, + + if (nexthop->type == NEXTHOP_TYPE_IPV6 + || nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX) { +- nhi.gateway = &nexthop->gate; ++ /* Special handling for IPv4 route with IPv6 Link Local next hop ++ */ ++ if (ri->af == AF_INET) ++ nhi.gateway = &ipv4ll_gateway; ++ else ++ nhi.gateway = &nexthop->gate; + } + + if (nexthop->type == NEXTHOP_TYPE_IFINDEX) { +diff --git a/zebra/zebra_fpm_private.h b/zebra/zebra_fpm_private.h +index c169ee8c2..13415c7e1 100644 +--- a/zebra/zebra_fpm_private.h ++++ b/zebra/zebra_fpm_private.h +@@ -97,6 +97,8 @@ extern int zfpm_netlink_encode_mac(struct fpm_mac_info_t *mac, char *in_buf, + + extern struct route_entry *zfpm_route_for_update(rib_dest_t *dest); + ++extern union g_addr ipv4ll_gateway; ++ + #ifdef __cplusplus + } + #endif diff --git a/src/sonic-frr/patch/series b/src/sonic-frr/patch/series index 376b6ce10c..b77931d57e 100644 --- a/src/sonic-frr/patch/series +++ b/src/sonic-frr/patch/series @@ -8,3 +8,4 @@ 0009-Add-bgp-bestpath-peer-type-multipath-relax.patch 0009-Link-local-scope-was-not-set-while-binding-socket-for-bgp-ipv6-link-local-neighbors.patch 0010-remove-doc-png-install.patch +0011-Ipv4-Link-local-address-for-Ipv6-linl-local-nexthop.patch