1 From: Felix Fietkau <nbd@nbd.name>
2 Subject: [PATCH] bridge: multicast to unicast
4 Implement optinal multicast->unicast conversion for igmp snooping
6 --- a/include/linux/if_bridge.h
7 +++ b/include/linux/if_bridge.h
8 @@ -46,6 +46,7 @@ struct br_ip_list {
9 #define BR_LEARNING_SYNC BIT(9)
10 #define BR_PROXYARP_WIFI BIT(10)
11 #define BR_ISOLATE_MODE BIT(11)
12 +#define BR_MULTICAST_TO_UCAST BIT(12)
14 #define BR_DEFAULT_AGEING_TIME (300 * HZ)
16 --- a/net/bridge/br_multicast.c
17 +++ b/net/bridge/br_multicast.c
18 @@ -42,12 +42,13 @@ static void br_multicast_add_router(stru
19 static void br_ip4_multicast_leave_group(struct net_bridge *br,
20 struct net_bridge_port *port,
24 + const unsigned char *src);
25 #if IS_ENABLED(CONFIG_IPV6)
26 static void br_ip6_multicast_leave_group(struct net_bridge *br,
27 struct net_bridge_port *port,
28 const struct in6_addr *group,
30 + __u16 vid, const unsigned char *src);
32 unsigned int br_mdb_rehash_seq;
34 @@ -652,7 +653,8 @@ struct net_bridge_port_group *br_multica
35 struct net_bridge_port *port,
37 struct net_bridge_port_group __rcu *next,
38 - unsigned char state)
39 + unsigned char state,
40 + const unsigned char *src)
42 struct net_bridge_port_group *p;
44 @@ -667,12 +669,33 @@ struct net_bridge_port_group *br_multica
45 hlist_add_head(&p->mglist, &port->mglist);
46 setup_timer(&p->timer, br_multicast_port_group_expired,
48 + if ((port->flags & BR_MULTICAST_TO_UCAST) && src) {
49 + memcpy(p->eth_addr, src, ETH_ALEN);
55 +static bool br_port_group_equal(struct net_bridge_port_group *p,
56 + struct net_bridge_port *port,
57 + const unsigned char *src)
59 + if (p->port != port)
68 + return ether_addr_equal(src, p->eth_addr);
71 static int br_multicast_add_group(struct net_bridge *br,
72 struct net_bridge_port *port,
73 - struct br_ip *group)
74 + struct br_ip *group,
75 + const unsigned char *src)
77 struct net_bridge_mdb_entry *mp;
78 struct net_bridge_port_group *p;
79 @@ -699,13 +722,13 @@ static int br_multicast_add_group(struct
81 (p = mlock_dereference(*pp, br)) != NULL;
83 - if (p->port == port)
84 + if (br_port_group_equal(p, port, src))
86 if ((unsigned long)p->port < (unsigned long)port)
90 - p = br_multicast_new_port_group(port, group, *pp, MDB_TEMPORARY);
91 + p = br_multicast_new_port_group(port, group, *pp, MDB_TEMPORARY, src);
94 rcu_assign_pointer(*pp, p);
95 @@ -724,7 +747,7 @@ err:
96 static int br_ip4_multicast_add_group(struct net_bridge *br,
97 struct net_bridge_port *port,
100 + __u16 vid, const unsigned char *src)
102 struct br_ip br_group;
104 @@ -735,14 +758,14 @@ static int br_ip4_multicast_add_group(st
105 br_group.proto = htons(ETH_P_IP);
108 - return br_multicast_add_group(br, port, &br_group);
109 + return br_multicast_add_group(br, port, &br_group, src);
112 #if IS_ENABLED(CONFIG_IPV6)
113 static int br_ip6_multicast_add_group(struct net_bridge *br,
114 struct net_bridge_port *port,
115 const struct in6_addr *group,
117 + __u16 vid, const unsigned char *src)
119 struct br_ip br_group;
121 @@ -753,7 +776,7 @@ static int br_ip6_multicast_add_group(st
122 br_group.proto = htons(ETH_P_IPV6);
125 - return br_multicast_add_group(br, port, &br_group);
126 + return br_multicast_add_group(br, port, &br_group, src);
130 @@ -1003,6 +1026,7 @@ static int br_ip4_multicast_igmp3_report
134 + const unsigned char *src;
135 struct igmpv3_report *ih;
136 struct igmpv3_grec *grec;
138 @@ -1043,12 +1067,13 @@ static int br_ip4_multicast_igmp3_report
142 + src = eth_hdr(skb)->h_source;
143 if ((type == IGMPV3_CHANGE_TO_INCLUDE ||
144 type == IGMPV3_MODE_IS_INCLUDE) &&
145 ntohs(grec->grec_nsrcs) == 0) {
146 - br_ip4_multicast_leave_group(br, port, group, vid);
147 + br_ip4_multicast_leave_group(br, port, group, vid, src);
149 - err = br_ip4_multicast_add_group(br, port, group, vid);
150 + err = br_ip4_multicast_add_group(br, port, group, vid, src);
154 @@ -1063,6 +1088,7 @@ static int br_ip6_multicast_mld2_report(
158 + const unsigned char *src = eth_hdr(skb)->h_source;
159 struct icmp6hdr *icmp6h;
160 struct mld2_grec *grec;
162 @@ -1114,10 +1140,10 @@ static int br_ip6_multicast_mld2_report(
163 grec->grec_type == MLD2_MODE_IS_INCLUDE) &&
164 ntohs(*nsrcs) == 0) {
165 br_ip6_multicast_leave_group(br, port, &grec->grec_mca,
169 err = br_ip6_multicast_add_group(br, port,
170 - &grec->grec_mca, vid);
171 + &grec->grec_mca, vid, src);
175 @@ -1432,7 +1458,8 @@ br_multicast_leave_group(struct net_brid
176 struct net_bridge_port *port,
178 struct bridge_mcast_other_query *other_query,
179 - struct bridge_mcast_own_query *own_query)
180 + struct bridge_mcast_own_query *own_query,
181 + const unsigned char *src)
183 struct net_bridge_mdb_htable *mdb;
184 struct net_bridge_mdb_entry *mp;
185 @@ -1456,7 +1483,7 @@ br_multicast_leave_group(struct net_brid
186 for (pp = &mp->ports;
187 (p = mlock_dereference(*pp, br)) != NULL;
189 - if (p->port != port)
190 + if (!br_port_group_equal(p, port, src))
193 rcu_assign_pointer(*pp, p->next);
194 @@ -1519,7 +1546,7 @@ br_multicast_leave_group(struct net_brid
195 for (p = mlock_dereference(mp->ports, br);
197 p = mlock_dereference(p->next, br)) {
198 - if (p->port != port)
199 + if (!br_port_group_equal(p, port, src))
202 if (!hlist_unhashed(&p->mglist) &&
203 @@ -1537,8 +1564,8 @@ out:
205 static void br_ip4_multicast_leave_group(struct net_bridge *br,
206 struct net_bridge_port *port,
209 + __be32 group, __u16 vid,
210 + const unsigned char *src)
212 struct br_ip br_group;
213 struct bridge_mcast_own_query *own_query;
214 @@ -1553,14 +1580,14 @@ static void br_ip4_multicast_leave_group
217 br_multicast_leave_group(br, port, &br_group, &br->ip4_other_query,
222 #if IS_ENABLED(CONFIG_IPV6)
223 static void br_ip6_multicast_leave_group(struct net_bridge *br,
224 struct net_bridge_port *port,
225 const struct in6_addr *group,
227 + __u16 vid, const unsigned char *src)
229 struct br_ip br_group;
230 struct bridge_mcast_own_query *own_query;
231 @@ -1575,7 +1602,7 @@ static void br_ip6_multicast_leave_group
234 br_multicast_leave_group(br, port, &br_group, &br->ip6_other_query,
240 @@ -1584,6 +1611,7 @@ static int br_multicast_ipv4_rcv(struct
244 + const unsigned char *src;
245 struct sk_buff *skb_trimmed = NULL;
248 @@ -1600,12 +1628,13 @@ static int br_multicast_ipv4_rcv(struct
250 BR_INPUT_SKB_CB(skb)->igmp = 1;
252 + src = eth_hdr(skb)->h_source;
255 case IGMP_HOST_MEMBERSHIP_REPORT:
256 case IGMPV2_HOST_MEMBERSHIP_REPORT:
257 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
258 - err = br_ip4_multicast_add_group(br, port, ih->group, vid);
259 + err = br_ip4_multicast_add_group(br, port, ih->group, vid, src);
261 case IGMPV3_HOST_MEMBERSHIP_REPORT:
262 err = br_ip4_multicast_igmp3_report(br, port, skb_trimmed, vid);
263 @@ -1614,7 +1643,7 @@ static int br_multicast_ipv4_rcv(struct
264 err = br_ip4_multicast_query(br, port, skb_trimmed, vid);
266 case IGMP_HOST_LEAVE_MESSAGE:
267 - br_ip4_multicast_leave_group(br, port, ih->group, vid);
268 + br_ip4_multicast_leave_group(br, port, ih->group, vid, src);
272 @@ -1630,6 +1659,7 @@ static int br_multicast_ipv6_rcv(struct
276 + const unsigned char *src;
277 struct sk_buff *skb_trimmed = NULL;
280 @@ -1649,8 +1679,9 @@ static int br_multicast_ipv6_rcv(struct
282 switch (mld->mld_type) {
283 case ICMPV6_MGM_REPORT:
284 + src = eth_hdr(skb)->h_source;
285 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
286 - err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid);
287 + err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid, src);
289 case ICMPV6_MLD2_REPORT:
290 err = br_ip6_multicast_mld2_report(br, port, skb_trimmed, vid);
291 @@ -1659,7 +1690,8 @@ static int br_multicast_ipv6_rcv(struct
292 err = br_ip6_multicast_query(br, port, skb_trimmed, vid);
294 case ICMPV6_MGM_REDUCTION:
295 - br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid);
296 + src = eth_hdr(skb)->h_source;
297 + br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid, src);
301 --- a/net/bridge/br_private.h
302 +++ b/net/bridge/br_private.h
303 @@ -157,7 +157,9 @@ struct net_bridge_port_group {
305 struct timer_list timer;
307 + unsigned char eth_addr[ETH_ALEN];
312 struct net_bridge_mdb_entry
313 @@ -555,7 +557,8 @@ void br_multicast_free_pg(struct rcu_hea
314 struct net_bridge_port_group *
315 br_multicast_new_port_group(struct net_bridge_port *port, struct br_ip *group,
316 struct net_bridge_port_group __rcu *next,
317 - unsigned char state);
318 + unsigned char state,
319 + const unsigned char *src);
320 void br_mdb_init(void);
321 void br_mdb_uninit(void);
322 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
323 --- a/net/bridge/br_mdb.c
324 +++ b/net/bridge/br_mdb.c
325 @@ -416,7 +416,7 @@ static int br_mdb_add_group(struct net_b
329 - p = br_multicast_new_port_group(port, group, *pp, state);
330 + p = br_multicast_new_port_group(port, group, *pp, state, NULL);
333 rcu_assign_pointer(*pp, p);
334 --- a/net/bridge/br_forward.c
335 +++ b/net/bridge/br_forward.c
336 @@ -192,6 +192,34 @@ out:
340 +static struct net_bridge_port *maybe_deliver_addr(
341 + struct net_bridge_port *prev, struct net_bridge_port *p,
342 + struct sk_buff *skb, const unsigned char *addr,
343 + void (*__packet_hook)(const struct net_bridge_port *p,
344 + struct sk_buff *skb))
346 + struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
347 + const unsigned char *src = eth_hdr(skb)->h_source;
349 + if (!should_deliver(p, skb))
352 + /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
353 + if (skb->dev == p->dev && ether_addr_equal(src, addr))
356 + skb = skb_copy(skb, GFP_ATOMIC);
358 + dev->stats.tx_dropped++;
362 + memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
363 + __packet_hook(p, skb);
368 /* called under bridge lock */
369 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
370 struct sk_buff *skb0,
371 @@ -264,6 +292,7 @@ static void br_multicast_flood(struct ne
372 struct net_bridge_port *prev = NULL;
373 struct net_bridge_port_group *p;
374 struct hlist_node *rp;
375 + const unsigned char *addr;
377 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
378 p = mdst ? rcu_dereference(mdst->ports) : NULL;
379 @@ -274,10 +303,19 @@ static void br_multicast_flood(struct ne
380 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
383 - port = (unsigned long)lport > (unsigned long)rport ?
386 - prev = maybe_deliver(prev, port, skb, __packet_hook);
387 + if ((unsigned long)lport > (unsigned long)rport) {
389 + addr = p->unicast ? p->eth_addr : NULL;
396 + prev = maybe_deliver_addr(prev, port, skb, addr,
399 + prev = maybe_deliver(prev, port, skb, __packet_hook);
403 --- a/net/bridge/br_sysfs_if.c
404 +++ b/net/bridge/br_sysfs_if.c
405 @@ -204,6 +204,7 @@ static BRPORT_ATTR(multicast_router, S_I
406 store_multicast_router);
408 BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
409 +BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UCAST);
412 static const struct brport_attribute *brport_attrs[] = {
413 @@ -230,6 +231,7 @@ static const struct brport_attribute *br
414 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
415 &brport_attr_multicast_router,
416 &brport_attr_multicast_fast_leave,
417 + &brport_attr_multicast_to_unicast,
419 &brport_attr_proxyarp,
420 &brport_attr_proxyarp_wifi,