1 From: Felix Fietkau <nbd@openwrt.org>
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 /* values as per ieee8021QBridgeFdbAgingTime */
15 #define BR_MIN_AGEING_TIME (10 * 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 @@ -649,7 +650,8 @@ 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 @@ -664,12 +666,33 @@ 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 @@ -696,13 +719,13 @@ 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 @@ -721,7 +744,7 @@ 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 @@ -732,14 +755,14 @@ 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 @@ -750,7 +773,7 @@ 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 @@ -995,6 +1018,7 @@ static int br_ip4_multicast_igmp3_report
134 + const unsigned char *src;
135 struct igmpv3_report *ih;
136 struct igmpv3_grec *grec;
138 @@ -1038,9 +1062,10 @@ static int br_ip4_multicast_igmp3_report
139 if ((type == IGMPV3_CHANGE_TO_INCLUDE ||
140 type == IGMPV3_MODE_IS_INCLUDE) &&
141 ntohs(grec->grec_nsrcs) == 0) {
142 - br_ip4_multicast_leave_group(br, port, group, vid);
143 + br_ip4_multicast_leave_group(br, port, group, vid, src);
145 - err = br_ip4_multicast_add_group(br, port, group, vid);
146 + src = eth_hdr(skb)->h_source;
147 + err = br_ip4_multicast_add_group(br, port, group, vid, src);
151 @@ -1055,6 +1080,7 @@ static int br_ip6_multicast_mld2_report(
155 + const unsigned char *src = eth_hdr(skb)->h_source;
156 struct icmp6hdr *icmp6h;
157 struct mld2_grec *grec;
159 @@ -1106,10 +1132,10 @@ static int br_ip6_multicast_mld2_report(
160 grec->grec_type == MLD2_MODE_IS_INCLUDE) &&
161 ntohs(*nsrcs) == 0) {
162 br_ip6_multicast_leave_group(br, port, &grec->grec_mca,
166 err = br_ip6_multicast_add_group(br, port,
167 - &grec->grec_mca, vid);
168 + &grec->grec_mca, vid, src);
172 @@ -1422,7 +1448,8 @@ br_multicast_leave_group(struct net_brid
173 struct net_bridge_port *port,
175 struct bridge_mcast_other_query *other_query,
176 - struct bridge_mcast_own_query *own_query)
177 + struct bridge_mcast_own_query *own_query,
178 + const unsigned char *src)
180 struct net_bridge_mdb_htable *mdb;
181 struct net_bridge_mdb_entry *mp;
182 @@ -1446,7 +1473,7 @@ br_multicast_leave_group(struct net_brid
183 for (pp = &mp->ports;
184 (p = mlock_dereference(*pp, br)) != NULL;
186 - if (p->port != port)
187 + if (!br_port_group_equal(p, port, src))
190 rcu_assign_pointer(*pp, p->next);
191 @@ -1509,7 +1536,7 @@ br_multicast_leave_group(struct net_brid
192 for (p = mlock_dereference(mp->ports, br);
194 p = mlock_dereference(p->next, br)) {
195 - if (p->port != port)
196 + if (!br_port_group_equal(p, port, src))
199 if (!hlist_unhashed(&p->mglist) &&
200 @@ -1527,8 +1554,8 @@ out:
202 static void br_ip4_multicast_leave_group(struct net_bridge *br,
203 struct net_bridge_port *port,
206 + __be32 group, __u16 vid,
207 + const unsigned char *src)
209 struct br_ip br_group;
210 struct bridge_mcast_own_query *own_query;
211 @@ -1543,14 +1570,14 @@ static void br_ip4_multicast_leave_group
214 br_multicast_leave_group(br, port, &br_group, &br->ip4_other_query,
219 #if IS_ENABLED(CONFIG_IPV6)
220 static void br_ip6_multicast_leave_group(struct net_bridge *br,
221 struct net_bridge_port *port,
222 const struct in6_addr *group,
224 + __u16 vid, const unsigned char *src)
226 struct br_ip br_group;
227 struct bridge_mcast_own_query *own_query;
228 @@ -1565,7 +1592,7 @@ static void br_ip6_multicast_leave_group
231 br_multicast_leave_group(br, port, &br_group, &br->ip6_other_query,
237 @@ -1574,6 +1601,7 @@ static int br_multicast_ipv4_rcv(struct
241 + const unsigned char *src;
242 struct sk_buff *skb_trimmed = NULL;
245 @@ -1590,12 +1618,13 @@ static int br_multicast_ipv4_rcv(struct
247 BR_INPUT_SKB_CB(skb)->igmp = 1;
249 + src = eth_hdr(skb)->h_source;
252 case IGMP_HOST_MEMBERSHIP_REPORT:
253 case IGMPV2_HOST_MEMBERSHIP_REPORT:
254 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
255 - err = br_ip4_multicast_add_group(br, port, ih->group, vid);
256 + err = br_ip4_multicast_add_group(br, port, ih->group, vid, src);
258 case IGMPV3_HOST_MEMBERSHIP_REPORT:
259 err = br_ip4_multicast_igmp3_report(br, port, skb_trimmed, vid);
260 @@ -1604,7 +1633,7 @@ static int br_multicast_ipv4_rcv(struct
261 err = br_ip4_multicast_query(br, port, skb_trimmed, vid);
263 case IGMP_HOST_LEAVE_MESSAGE:
264 - br_ip4_multicast_leave_group(br, port, ih->group, vid);
265 + br_ip4_multicast_leave_group(br, port, ih->group, vid, src);
269 @@ -1620,6 +1649,7 @@ static int br_multicast_ipv6_rcv(struct
273 + const unsigned char *src;
274 struct sk_buff *skb_trimmed = NULL;
277 @@ -1639,8 +1669,9 @@ static int br_multicast_ipv6_rcv(struct
279 switch (mld->mld_type) {
280 case ICMPV6_MGM_REPORT:
281 + src = eth_hdr(skb)->h_source;
282 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
283 - err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid);
284 + err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid, src);
286 case ICMPV6_MLD2_REPORT:
287 err = br_ip6_multicast_mld2_report(br, port, skb_trimmed, vid);
288 @@ -1649,7 +1680,8 @@ static int br_multicast_ipv6_rcv(struct
289 err = br_ip6_multicast_query(br, port, skb_trimmed, vid);
291 case ICMPV6_MGM_REDUCTION:
292 - br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid);
293 + src = eth_hdr(skb)->h_source;
294 + br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid, src);
298 --- a/net/bridge/br_private.h
299 +++ b/net/bridge/br_private.h
300 @@ -158,6 +158,9 @@ struct net_bridge_port_group {
301 struct timer_list timer;
305 + unsigned char eth_addr[ETH_ALEN];
309 struct net_bridge_mdb_entry
310 @@ -554,7 +557,8 @@ void br_multicast_free_pg(struct rcu_hea
311 struct net_bridge_port_group *
312 br_multicast_new_port_group(struct net_bridge_port *port, struct br_ip *group,
313 struct net_bridge_port_group __rcu *next,
314 - unsigned char state);
315 + unsigned char state,
316 + const unsigned char *src);
317 void br_mdb_init(void);
318 void br_mdb_uninit(void);
319 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
320 --- a/net/bridge/br_mdb.c
321 +++ b/net/bridge/br_mdb.c
322 @@ -416,7 +416,7 @@ static int br_mdb_add_group(struct net_b
326 - p = br_multicast_new_port_group(port, group, *pp, state);
327 + p = br_multicast_new_port_group(port, group, *pp, state, NULL);
330 rcu_assign_pointer(*pp, p);
331 --- a/net/bridge/br_forward.c
332 +++ b/net/bridge/br_forward.c
333 @@ -192,6 +192,34 @@ out:
337 +static struct net_bridge_port *maybe_deliver_addr(
338 + struct net_bridge_port *prev, struct net_bridge_port *p,
339 + struct sk_buff *skb, const unsigned char *addr,
340 + void (*__packet_hook)(const struct net_bridge_port *p,
341 + struct sk_buff *skb))
343 + struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
344 + const unsigned char *src = eth_hdr(skb)->h_source;
346 + if (!should_deliver(p, skb))
349 + /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
350 + if (skb->dev == p->dev && ether_addr_equal(src, addr))
353 + skb = skb_copy(skb, GFP_ATOMIC);
355 + dev->stats.tx_dropped++;
359 + memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
360 + __packet_hook(p, skb);
365 /* called under bridge lock */
366 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
367 struct sk_buff *skb0,
368 @@ -264,6 +292,7 @@ static void br_multicast_flood(struct ne
369 struct net_bridge_port *prev = NULL;
370 struct net_bridge_port_group *p;
371 struct hlist_node *rp;
372 + const unsigned char *addr;
374 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
375 p = mdst ? rcu_dereference(mdst->ports) : NULL;
376 @@ -274,10 +303,19 @@ static void br_multicast_flood(struct ne
377 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
380 - port = (unsigned long)lport > (unsigned long)rport ?
383 - prev = maybe_deliver(prev, port, skb, __packet_hook);
384 + if ((unsigned long)lport > (unsigned long)rport) {
386 + addr = p->unicast ? p->eth_addr : NULL;
393 + prev = maybe_deliver_addr(prev, port, skb, addr,
396 + prev = maybe_deliver(prev, port, skb, __packet_hook);
400 --- a/net/bridge/br_sysfs_if.c
401 +++ b/net/bridge/br_sysfs_if.c
402 @@ -204,6 +204,7 @@ static BRPORT_ATTR(multicast_router, S_I
403 store_multicast_router);
405 BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
406 +BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UCAST);
409 static const struct brport_attribute *brport_attrs[] = {
410 @@ -230,6 +231,7 @@ static const struct brport_attribute *br
411 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
412 &brport_attr_multicast_router,
413 &brport_attr_multicast_fast_leave,
414 + &brport_attr_multicast_to_unicast,
416 &brport_attr_proxyarp,
417 &brport_attr_proxyarp_wifi,