bridge: fdb: Fix FDB dump with strict checking disabled

While iproute2 correctly uses ifinfomsg struct as the ancillary header
when requesting an FDB dump on old kernels, it sets the message type to
RTM_GETLINK. This results in wrong reply being returned.

Fix this by using RTM_GETNEIGH instead.

Before:
$ bridge fdb show brport dummy0
Not RTM_NEWNEIGH: 00000158 00000010 00000002

After:
$ bridge fdb show brport dummy0
2a:0b:41:1c:92:d3 vlan 1 master br0 permanent
2a:0b:41:1c:92:d3 master br0 permanent
33:33:00:00:00:01 self permanent
01:00:5e:00:00:01 self permanent

Fixes: 05880354c2cf ("bridge: fdb: Fix filtering with strict checking disabled")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: LiLiang <liali@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/bridge/fdb.c b/bridge/fdb.c
index f75e953a80e242d8d888e24dac752e869729e8ff..c4bf40390f42b770626d1af6e5ddef0e6fa161e6 100644 (file)
--- a/bridge/fdb.c
+++ b/bridge/fdb.c
@@ -346,8 +346,7 @@ static int fdb_show(int argc, char **argv)
        if (rth.flags & RTNL_HANDLE_F_STRICT_CHK)
                rc = rtnl_neighdump_req(&rth, PF_BRIDGE, fdb_dump_filter);
        else
-               rc = rtnl_linkdump_req_filter_fn(&rth, PF_BRIDGE,
-                                                fdb_linkdump_filter);
+               rc = rtnl_fdb_linkdump_req_filter_fn(&rth, fdb_linkdump_filter);
        if (rc < 0) {
                perror("Cannot send dump request");
                exit(1);

diff --git a/include/libnetlink.h b/include/libnetlink.h
index 0854d6ad2fabec5ad41756c5c6fbab1318e87c3a..503b3ec11bb6bda345e663f04adedde39289c338 100644 (file)
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -81,6 +81,9 @@ int rtnl_linkdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
 int rtnl_linkdump_req_filter_fn(struct rtnl_handle *rth, int fam,
                                req_filter_fn_t fn)
        __attribute__((warn_unused_result));
+int rtnl_fdb_linkdump_req_filter_fn(struct rtnl_handle *rth,
+                                   req_filter_fn_t filter_fn)
+       __attribute__((warn_unused_result));
 int rtnl_statsdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
        __attribute__((warn_unused_result));
 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req,

diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index 3beb4342d890af45ef78c75234bd8dbf2bc583b4..1892a02ab5d0d73776c9882ffc77edcd2c663d01 100644 (file)
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -503,6 +503,29 @@ int rtnl_linkdump_req_filter_fn(struct rtnl_handle *rth, int family,
        return __rtnl_linkdump_req(rth, family);
 }
 
+int rtnl_fdb_linkdump_req_filter_fn(struct rtnl_handle *rth,
+                                   req_filter_fn_t filter_fn)
+{
+       struct {
+               struct nlmsghdr nlh;
+               struct ifinfomsg ifm;
+               char buf[128];
+       } req = {
+               .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+               .nlh.nlmsg_type = RTM_GETNEIGH,
+               .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+               .nlh.nlmsg_seq = rth->dump = ++rth->seq,
+               .ifm.ifi_family = PF_BRIDGE,
+       };
+       int err;
+
+       err = filter_fn(&req.nlh, sizeof(req));
+       if (err)
+               return err;
+
+       return send(rth->fd, &req, sizeof(req), 0);
+}
+
 int rtnl_statsdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
 {
        struct {