Block traffic to a specific host with the command: bridge fdb add <MAC> vlan <vid> dev br0 blackhole
Blackhole FDB entries can be added, deleted and replaced with ordinary FDB entries.
Example with output:
$ bridge fdb add 10:10:10:10:10:10 dev br0 blackhole $ bridge -d fdb show dev br0 10:10:10:10:10:10 vlan 1 blackhole master br0 permanent 10:10:10:10:10:10 blackhole master br0 permanent $ bridge -d -j -p fdb show dev br0 [ { "mac": "10:10:10:10:10:10", "vlan": 1, "flags": [ "blackhole" ], "master": "br0", "state": "permanent" },{ "mac": "10:10:10:10:10:10", "flags": [ "blackhole" ], "master": "br0", "state": "permanent" } ]
Signed-off-by: Hans Schultz netdev@kapio-technology.com --- bridge/fdb.c | 13 ++++++++++++- man/man8/bridge.8 | 12 ++++++++++++ 2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/bridge/fdb.c b/bridge/fdb.c index f1f0a5bb..1c8c50a8 100644 --- a/bridge/fdb.c +++ b/bridge/fdb.c @@ -38,7 +38,7 @@ static void usage(void) fprintf(stderr, "Usage: bridge fdb { add | append | del | replace } ADDR dev DEV\n" " [ self ] [ master ] [ use ] [ router ] [ extern_learn ]\n" - " [ sticky ] [ local | static | dynamic ] [ vlan VID ]\n" + " [ sticky ] [ local | static | dynamic ] [ blackhole ] [ vlan VID ]\n" " { [ dst IPADDR ] [ port PORT] [ vni VNI ] | [ nhid NHID ] }\n" " [ via DEV ] [ src_vni VNI ]\n" " bridge fdb [ show [ br BRDEV ] [ brport DEV ] [ vlan VID ]\n" @@ -116,6 +116,9 @@ static void fdb_print_flags(FILE *fp, unsigned int flags, __u8 ext_flags) if (flags & NTF_STICKY) print_string(PRINT_ANY, NULL, "%s ", "sticky");
+ if (ext_flags & NTF_EXT_BLACKHOLE) + print_string(PRINT_ANY, NULL, "%s ", "blackhole"); + if (ext_flags & NTF_EXT_LOCKED) print_string(PRINT_ANY, NULL, "%s ", "locked");
@@ -421,6 +424,7 @@ static int fdb_modify(int cmd, int flags, int argc, char **argv) char *endptr; short vid = -1; __u32 nhid = 0; + __u32 ext_flags = 0;
while (argc > 0) { if (strcmp(*argv, "dev") == 0) { @@ -492,6 +496,8 @@ static int fdb_modify(int cmd, int flags, int argc, char **argv) req.ndm.ndm_flags |= NTF_EXT_LEARNED; } else if (matches(*argv, "sticky") == 0) { req.ndm.ndm_flags |= NTF_STICKY; + } else if (matches(*argv, "blackhole") == 0) { + ext_flags |= NTF_EXT_BLACKHOLE; } else { if (strcmp(*argv, "to") == 0) NEXT_ARG(); @@ -534,6 +540,11 @@ static int fdb_modify(int cmd, int flags, int argc, char **argv) if (dst_ok) addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen);
+ if (ext_flags && + addattr_l(&req.n, sizeof(req), NDA_FLAGS_EXT, &ext_flags, + sizeof(ext_flags)) < 0) + return -1; + if (vid >= 0) addattr16(&req.n, sizeof(req), NDA_VLAN, vid); if (nhid > 0) diff --git a/man/man8/bridge.8 b/man/man8/bridge.8 index f4f1d807..0119a2a9 100644 --- a/man/man8/bridge.8 +++ b/man/man8/bridge.8 @@ -85,6 +85,13 @@ bridge - show / manipulate bridge addresses and devices .B nhid .IR NHID " } "
+.ti -8 +.BR "bridge fdb" " { " add " | " del " } " +.I LLADR +.B dev +.IR BRDEV " [ " +.BR self " ] [ " local " ] [ " blackhole " ] " + .ti -8 .BR "bridge fdb" " [ [ " show " ] [ " .B br @@ -701,6 +708,11 @@ controller learnt dynamic entry. Kernel will not age such an entry. - this entry will not change its port due to learning. .sp
+.B blackhole +- this entry will silently discard all matching packets. The entry must +be added as a local permanent entry. +.sp + .in -8 The next command line parameters apply only when the specified device