From e492ad08fc347ebf40979d3a6baa9d7b8917c76b Mon Sep 17 00:00:00 2001 From: Olivier Cochard Date: Sat, 30 May 2026 01:17:28 +0200 Subject: [PATCH] netlink/route: extend pre-2.6.19 Linux compat shim to del/getroute Commit f34aca55adef ("netlink/route: provide pre-2.6.19 Linux compat shim", 2024-06) fixed the partial fix for net/bird2 on the netlink path by mapping the legacy 8-bit struct rtmsg::rtm_table field onto the modern 32-bit RTA_TABLE attribute when the latter is absent. That fix, however, was only applied to rtnl_handle_newroute. The two sibling handlers: rtnl_handle_delroute and rtnl_handle_getroute were left looking at attrs.rta_table directly. They are reachable from exactly the same client (bird, in its netlink scan path), so any FIB number that fits in 8 bits silently maps to RT_TABLE_UNSPEC in those handlers. Reviewed by: melifaro (previous version) Approved by: emaste MFC after: 1 week Sponsored by: Netflix --- sys/netlink/route/rt.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/sys/netlink/route/rt.c b/sys/netlink/route/rt.c index 17aae399c10a..39ecb537d365 100644 --- a/sys/netlink/route/rt.c +++ b/sys/netlink/route/rt.c @@ -978,6 +978,14 @@ create_nexthop_from_attrs(struct nl_parsed_route *attrs, return (nh); } +/* pre-2.6.19 Linux API compatibility: prefer RTA_TABLE, fall back to rtm_table */ +static inline void +old_linux_compat(struct nl_parsed_route *attrs) +{ + if (attrs->rtm_table > 0 && attrs->rta_table == 0) + attrs->rta_table = attrs->rtm_table; +} + static int rtnl_handle_newroute(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *npt) @@ -997,9 +1005,7 @@ rtnl_handle_newroute(struct nlmsghdr *hdr, struct nlpcb *nlp, return (EINVAL); } - /* pre-2.6.19 Linux API compatibility */ - if (attrs.rtm_table > 0 && attrs.rta_table == 0) - attrs.rta_table = attrs.rtm_table; + old_linux_compat(&attrs); if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family > AF_MAX) { NLMSG_REPORT_ERR_MSG(npt, "invalid fib"); return (EINVAL); @@ -1066,6 +1072,7 @@ rtnl_handle_delroute(struct nlmsghdr *hdr, struct nlpcb *nlp, return (ESRCH); } + old_linux_compat(&attrs); if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family > AF_MAX) { NLMSG_REPORT_ERR_MSG(npt, "invalid fib"); return (EINVAL); @@ -1089,6 +1096,7 @@ rtnl_handle_getroute(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate * if (error != 0) return (error); + old_linux_compat(&attrs); if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family > AF_MAX) { NLMSG_REPORT_ERR_MSG(npt, "invalid fib"); return (EINVAL);