[PATCH iproute2-next 6/6] bridge: mdb: Add replace support

[Ido Schimmel <idosch@nvidia.com>]

Allow user space to replace MDB port group entries by specifying the
'NLM_F_REPLACE' flag in the netlink message header.

Examples:

 # bridge mdb replace dev br0 port dummy10 grp 239.1.1.1 permanent source_list 192.0.2.1,192.0.2.2 filter_mode include
 # bridge -d -s mdb show
 dev br0 port dummy10 grp 239.1.1.1 src 192.0.2.2 permanent filter_mode include proto static     0.00
 dev br0 port dummy10 grp 239.1.1.1 src 192.0.2.1 permanent filter_mode include proto static     0.00
 dev br0 port dummy10 grp 239.1.1.1 permanent filter_mode include source_list 192.0.2.2/0.00,192.0.2.1/0.00 proto static     0.00

 # bridge mdb replace dev br0 port dummy10 grp 239.1.1.1 permanent source_list 192.0.2.1,192.0.2.3 filter_mode exclude proto zebra
 # bridge -d -s mdb show
 dev br0 port dummy10 grp 239.1.1.1 src 192.0.2.3 permanent filter_mode include proto zebra  blocked    0.00
 dev br0 port dummy10 grp 239.1.1.1 src 192.0.2.1 permanent filter_mode include proto zebra  blocked    0.00
 dev br0 port dummy10 grp 239.1.1.1 permanent filter_mode exclude source_list 192.0.2.3/0.00,192.0.2.1/0.00 proto zebra     0.00

 # bridge mdb replace dev br0 port dummy10 grp 239.1.1.1 temp source_list 192.0.2.4,192.0.2.3 filter_mode include proto bgp
 # bridge -d -s mdb show
 dev br0 port dummy10 grp 239.1.1.1 src 192.0.2.4 temp filter_mode include proto bgp     0.00
 dev br0 port dummy10 grp 239.1.1.1 src 192.0.2.3 temp filter_mode include proto bgp     0.00
 dev br0 port dummy10 grp 239.1.1.1 temp filter_mode include source_list 192.0.2.4/259.44,192.0.2.3/259.44 proto bgp     0.00

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 bridge/mdb.c      |  4 +++-
 man/man8/bridge.8 | 13 ++++++++++---
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/bridge/mdb.c b/bridge/mdb.c
index 195a032c211b..f323cd091fcc 100644
--- a/bridge/mdb.c
+++ b/bridge/mdb.c
@@ -31,7 +31,7 @@ static unsigned int filter_index, filter_vlan;
 static void usage(void)
 {
 	fprintf(stderr,
-		"Usage: bridge mdb { add | del } dev DEV port PORT grp GROUP [src SOURCE] [permanent | temp] [vid VID]\n"
+		"Usage: bridge mdb { add | del | replace } dev DEV port PORT grp GROUP [src SOURCE] [permanent | temp] [vid VID]\n"
 		"              [ filter_mode { include | exclude } ] [ source_list SOURCE_LIST ] [ proto PROTO ]\n"
 		"       bridge mdb {show} [ dev DEV ] [ vid VID ]\n");
 	exit(-1);
@@ -692,6 +692,8 @@ int do_mdb(int argc, char **argv)
 	if (argc > 0) {
 		if (matches(*argv, "add") == 0)
 			return mdb_modify(RTM_NEWMDB, NLM_F_CREATE|NLM_F_EXCL, argc-1, argv+1);
+		if (strcmp(*argv, "replace") == 0)
+			return mdb_modify(RTM_NEWMDB, NLM_F_CREATE|NLM_F_REPLACE, argc-1, argv+1);
 		if (matches(*argv, "delete") == 0)
 			return mdb_modify(RTM_DELMDB, 0, argc-1, argv+1);
 
diff --git a/man/man8/bridge.8 b/man/man8/bridge.8
index 3e6e928c895f..f73e538a3536 100644
--- a/man/man8/bridge.8
+++ b/man/man8/bridge.8
@@ -127,7 +127,7 @@ bridge \- show / manipulate bridge addresses and devices
 .BR [no]sticky " ] [ " [no]offloaded " ]"
 
 .ti -8
-.BR "bridge mdb" " { " add " | " del " } "
+.BR "bridge mdb" " { " add " | " del " | " replace " } "
 .B dev
 .I DEV
 .B port
@@ -898,8 +898,8 @@ if "no" is prepended then only entries without offloaded flag will be deleted.
 objects contain known IP or L2 multicast group addresses on a link.
 
 .P
-The corresponding commands display mdb entries, add new entries,
-and delete old ones.
+The corresponding commands display mdb entries, add new entries, replace
+entries and delete old ones.
 
 .SS bridge mdb add - add a new multicast group database entry
 
@@ -964,6 +964,13 @@ This command removes an existing mdb entry.
 The arguments are the same as with
 .BR "bridge mdb add" .
 
+.SS bridge mdb replace - replace a multicast group database entry
+If no matching entry is found, a new one will be created instead.
+
+.PP
+The arguments are the same as with
+.BR "bridge mdb add" .
+
 .SS bridge mdb show - list multicast group database entries
 
 This command displays the current multicast group membership table. The table
-- 
2.37.3