When dumping the routing table bird currently doesn't set the rtm_table netlink field to select any particular one but rather wants to get all at once. This can be problematic when multiple routing daemons are running on a system as the kernel's route modification performance goes down drasticly (by a factor of 20-200ish) when the table is being modified while it's being dumped. To avoid this situation we make bird do dumps on a per-kernel-table basis. This then allows the administrator to have multiple routing daemons use different kernel tables which sidesteps the problem. See also this discussion on the babel-users mailing list: https://alioth-lists.debian.net/pipermail/babel-users/2022-April/003902.html --- sysdep/cf/linux.h | 2 +- sysdep/linux/netlink.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/sysdep/cf/linux.h b/sysdep/cf/linux.h index 047d3764..d6211d16 100644 --- a/sysdep/cf/linux.h +++ b/sysdep/cf/linux.h @@ -9,7 +9,7 @@ #define CONFIG_AUTO_ROUTES #define CONFIG_SELF_CONSCIOUS #define CONFIG_MULTIPLE_TABLES -#define CONFIG_ALL_TABLES_AT_ONCE +#undef CONFIG_ALL_TABLES_AT_ONCE #define CONFIG_IP6_SADR_KERNEL #define CONFIG_MC_PROPER_SRC diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c index 29b744cb..003b7939 100644 --- a/sysdep/linux/netlink.c +++ b/sysdep/linux/netlink.c @@ -256,7 +256,7 @@ nl_request_dump_addr(int af) } static void -nl_request_dump_route(int af) +nl_request_dump_route(int af, int table_id) { struct { struct nlmsghdr nh; @@ -267,6 +267,7 @@ nl_request_dump_route(int af) .nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP, .nh.nlmsg_seq = ++(nl_scan.seq), .rtm.rtm_family = af, + .rtm.rtm_table = table_id, }; send(nl_scan.fd, &req, sizeof(req), 0); @@ -1976,13 +1977,13 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h) } void -krt_do_scan(struct krt_proto *p UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NULL */ +krt_do_scan(struct krt_proto *p) { struct nlmsghdr *h; struct nl_parse_state s; nl_parse_begin(&s, 1); - nl_request_dump_route(AF_UNSPEC); + nl_request_dump_route(AF_UNSPEC, KRT_CF->sys.table_id); while (h = nl_get_scan()) if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE) nl_parse_route(&s, h); -- 2.30.2