diff options
| -rw-r--r-- | sysdep/linux/netlink.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c index e41eb32d..12bacd35 100644 --- a/sysdep/linux/netlink.c +++ b/sysdep/linux/netlink.c @@ -1459,12 +1459,38 @@ done: return nl_exchange(&r->h, (op == NL_OP_DELETE)); } +static inline int +nl_allow_replace(struct krt_proto *p, rte *new) +{ + /* + * We use NL_OP_REPLACE for IPv4, it has an issue with not checking for + * matching rtm_protocol, but that is OK when dedicated priority is used. + * + * For IPv6, the NL_OP_REPLACE is still broken even in Linux 4.19 LTS + * (although it seems to be fixed in Linux 5.10 LTS) for sequence: + * + * ip route add 2001:db8::/32 via fe80::1 dev eth0 + * ip route replace 2001:db8::/32 dev eth0 + * + * (it ends with two routes instead of replacing the first by the second one) + * + * Replacing with direct and special type (e.g. unreachable) routes does not + * work, but replacing with regular routes work reliably + */ + + if (krt_ipv4(p)) + return 1; + + rta *a = new->attrs; + return (a->dest == RTD_UNICAST) && ipa_nonzero(a->nh.gw); +} + void krt_replace_rte(struct krt_proto *p, net *n UNUSED, rte *new, rte *old) { int err = 0; - if (old && new) + if (old && new && nl_allow_replace(p, new)) { err = nl_send_route(p, new, NL_OP_REPLACE); } |