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 extern void brioctl_set(int (*ioctl_hook)(struct net *, unsigned int, void __user *));
16 --- a/net/bridge/br_multicast.c
17 +++ b/net/bridge/br_multicast.c
18 @@ -635,7 +635,8 @@ struct net_bridge_port_group *br_multica
19 struct net_bridge_port *port,
21 struct net_bridge_port_group __rcu *next,
22 - unsigned char state)
23 + unsigned char state,
24 + const unsigned char *src)
26 struct net_bridge_port_group *p;
28 @@ -650,12 +651,33 @@ struct net_bridge_port_group *br_multica
29 hlist_add_head(&p->mglist, &port->mglist);
30 setup_timer(&p->timer, br_multicast_port_group_expired,
32 + if ((port->flags & BR_MULTICAST_TO_UCAST) && src) {
33 + memcpy(p->eth_addr, src, ETH_ALEN);
39 +static bool br_port_group_equal(struct net_bridge_port_group *p,
40 + struct net_bridge_port *port,
41 + const unsigned char *src)
43 + if (p->port != port)
52 + return ether_addr_equal(src, p->eth_addr);
55 static int br_multicast_add_group(struct net_bridge *br,
56 struct net_bridge_port *port,
57 - struct br_ip *group)
58 + struct br_ip *group,
59 + const unsigned char *src)
61 struct net_bridge_mdb_entry *mp;
62 struct net_bridge_port_group *p;
63 @@ -682,13 +704,13 @@ static int br_multicast_add_group(struct
65 (p = mlock_dereference(*pp, br)) != NULL;
67 - if (p->port == port)
68 + if (br_port_group_equal(p, port, src))
70 if ((unsigned long)p->port < (unsigned long)port)
74 - p = br_multicast_new_port_group(port, group, *pp, MDB_TEMPORARY);
75 + p = br_multicast_new_port_group(port, group, *pp, MDB_TEMPORARY, src);
78 rcu_assign_pointer(*pp, p);
79 @@ -707,7 +729,7 @@ err:
80 static int br_ip4_multicast_add_group(struct net_bridge *br,
81 struct net_bridge_port *port,
84 + __u16 vid, const unsigned char *src)
86 struct br_ip br_group;
88 @@ -718,14 +740,14 @@ static int br_ip4_multicast_add_group(st
89 br_group.proto = htons(ETH_P_IP);
92 - return br_multicast_add_group(br, port, &br_group);
93 + return br_multicast_add_group(br, port, &br_group, src);
96 #if IS_ENABLED(CONFIG_IPV6)
97 static int br_ip6_multicast_add_group(struct net_bridge *br,
98 struct net_bridge_port *port,
99 const struct in6_addr *group,
101 + __u16 vid, const unsigned char *src)
103 struct br_ip br_group;
105 @@ -736,7 +758,7 @@ static int br_ip6_multicast_add_group(st
106 br_group.proto = htons(ETH_P_IPV6);
109 - return br_multicast_add_group(br, port, &br_group);
110 + return br_multicast_add_group(br, port, &br_group, src);
114 @@ -966,6 +988,7 @@ static int br_ip4_multicast_igmp3_report
118 + const unsigned char *src;
119 struct igmpv3_report *ih;
120 struct igmpv3_grec *grec;
122 @@ -1009,7 +1032,8 @@ static int br_ip4_multicast_igmp3_report
126 - err = br_ip4_multicast_add_group(br, port, group, vid);
127 + src = eth_hdr(skb)->h_source;
128 + err = br_ip4_multicast_add_group(br, port, group, vid, src);
132 @@ -1023,6 +1047,7 @@ static int br_ip6_multicast_mld2_report(
136 + const unsigned char *src = eth_hdr(skb)->h_source;
137 struct icmp6hdr *icmp6h;
138 struct mld2_grec *grec;
140 @@ -1071,7 +1096,7 @@ static int br_ip6_multicast_mld2_report(
143 err = br_ip6_multicast_add_group(br, port, &grec->grec_mca,
149 @@ -1407,7 +1432,8 @@ br_multicast_leave_group(struct net_brid
150 struct net_bridge_port *port,
152 struct bridge_mcast_other_query *other_query,
153 - struct bridge_mcast_own_query *own_query)
154 + struct bridge_mcast_own_query *own_query,
155 + const unsigned char *src)
157 struct net_bridge_mdb_htable *mdb;
158 struct net_bridge_mdb_entry *mp;
159 @@ -1457,7 +1483,7 @@ br_multicast_leave_group(struct net_brid
160 for (pp = &mp->ports;
161 (p = mlock_dereference(*pp, br)) != NULL;
163 - if (p->port != port)
164 + if (!br_port_group_equal(p, port, src))
167 rcu_assign_pointer(*pp, p->next);
168 @@ -1491,7 +1517,7 @@ br_multicast_leave_group(struct net_brid
169 for (p = mlock_dereference(mp->ports, br);
171 p = mlock_dereference(p->next, br)) {
172 - if (p->port != port)
173 + if (!br_port_group_equal(p, port, src))
176 if (!hlist_unhashed(&p->mglist) &&
177 @@ -1509,8 +1535,8 @@ out:
179 static void br_ip4_multicast_leave_group(struct net_bridge *br,
180 struct net_bridge_port *port,
183 + __be32 group, __u16 vid,
184 + const unsigned char *src)
186 struct br_ip br_group;
187 struct bridge_mcast_own_query *own_query;
188 @@ -1525,14 +1551,14 @@ static void br_ip4_multicast_leave_group
191 br_multicast_leave_group(br, port, &br_group, &br->ip4_other_query,
196 #if IS_ENABLED(CONFIG_IPV6)
197 static void br_ip6_multicast_leave_group(struct net_bridge *br,
198 struct net_bridge_port *port,
199 const struct in6_addr *group,
201 + __u16 vid, const unsigned char *src)
203 struct br_ip br_group;
204 struct bridge_mcast_own_query *own_query;
205 @@ -1547,7 +1573,7 @@ static void br_ip6_multicast_leave_group
208 br_multicast_leave_group(br, port, &br_group, &br->ip6_other_query,
214 @@ -1556,6 +1582,7 @@ static int br_multicast_ipv4_rcv(struct
218 + const unsigned char *src;
219 struct sk_buff *skb2 = skb;
220 const struct iphdr *iph;
222 @@ -1624,12 +1651,13 @@ static int br_multicast_ipv4_rcv(struct
224 BR_INPUT_SKB_CB(skb)->igmp = 1;
226 + src = eth_hdr(skb)->h_source;
229 case IGMP_HOST_MEMBERSHIP_REPORT:
230 case IGMPV2_HOST_MEMBERSHIP_REPORT:
231 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
232 - err = br_ip4_multicast_add_group(br, port, ih->group, vid);
233 + err = br_ip4_multicast_add_group(br, port, ih->group, vid, src);
235 case IGMPV3_HOST_MEMBERSHIP_REPORT:
236 err = br_ip4_multicast_igmp3_report(br, port, skb2, vid);
237 @@ -1638,7 +1666,7 @@ static int br_multicast_ipv4_rcv(struct
238 err = br_ip4_multicast_query(br, port, skb2, vid);
240 case IGMP_HOST_LEAVE_MESSAGE:
241 - br_ip4_multicast_leave_group(br, port, ih->group, vid);
242 + br_ip4_multicast_leave_group(br, port, ih->group, vid, src);
246 @@ -1656,6 +1684,7 @@ static int br_multicast_ipv6_rcv(struct
250 + const unsigned char *src;
251 struct sk_buff *skb2;
252 const struct ipv6hdr *ip6h;
254 @@ -1763,9 +1792,11 @@ static int br_multicast_ipv6_rcv(struct
258 + src = eth_hdr(skb)->h_source;
259 mld = (struct mld_msg *)skb_transport_header(skb2);
260 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
261 - err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid);
262 + err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid,
266 case ICMPV6_MLD2_REPORT:
267 @@ -1781,8 +1812,9 @@ static int br_multicast_ipv6_rcv(struct
271 + src = eth_hdr(skb)->h_source;
272 mld = (struct mld_msg *)skb_transport_header(skb2);
273 - br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid);
274 + br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid, src);
278 --- a/net/bridge/br_private.h
279 +++ b/net/bridge/br_private.h
280 @@ -113,6 +113,9 @@ struct net_bridge_port_group {
281 struct timer_list timer;
285 + unsigned char eth_addr[ETH_ALEN];
289 struct net_bridge_mdb_entry
290 @@ -481,7 +484,8 @@ void br_multicast_free_pg(struct rcu_hea
291 struct net_bridge_port_group *
292 br_multicast_new_port_group(struct net_bridge_port *port, struct br_ip *group,
293 struct net_bridge_port_group __rcu *next,
294 - unsigned char state);
295 + unsigned char state,
296 + const unsigned char *src);
297 void br_mdb_init(void);
298 void br_mdb_uninit(void);
299 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
300 --- a/net/bridge/br_mdb.c
301 +++ b/net/bridge/br_mdb.c
302 @@ -343,7 +343,7 @@ static int br_mdb_add_group(struct net_b
306 - p = br_multicast_new_port_group(port, group, *pp, state);
307 + p = br_multicast_new_port_group(port, group, *pp, state, NULL);
310 rcu_assign_pointer(*pp, p);
311 --- a/net/bridge/br_forward.c
312 +++ b/net/bridge/br_forward.c
313 @@ -170,6 +170,34 @@ out:
317 +static struct net_bridge_port *maybe_deliver_addr(
318 + struct net_bridge_port *prev, struct net_bridge_port *p,
319 + struct sk_buff *skb, const unsigned char *addr,
320 + void (*__packet_hook)(const struct net_bridge_port *p,
321 + struct sk_buff *skb))
323 + struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
324 + const unsigned char *src = eth_hdr(skb)->h_source;
326 + if (!should_deliver(p, skb))
329 + /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
330 + if (skb->dev == p->dev && ether_addr_equal(src, addr))
333 + skb = skb_copy(skb, GFP_ATOMIC);
335 + dev->stats.tx_dropped++;
339 + memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
340 + __packet_hook(p, skb);
345 /* called under bridge lock */
346 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
347 struct sk_buff *skb0,
348 @@ -242,6 +270,7 @@ static void br_multicast_flood(struct ne
349 struct net_bridge_port *prev = NULL;
350 struct net_bridge_port_group *p;
351 struct hlist_node *rp;
352 + const unsigned char *addr;
354 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
355 p = mdst ? rcu_dereference(mdst->ports) : NULL;
356 @@ -252,10 +281,19 @@ static void br_multicast_flood(struct ne
357 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
360 - port = (unsigned long)lport > (unsigned long)rport ?
363 - prev = maybe_deliver(prev, port, skb, __packet_hook);
364 + if ((unsigned long)lport > (unsigned long)rport) {
366 + addr = p->unicast ? p->eth_addr : NULL;
373 + prev = maybe_deliver_addr(prev, port, skb, addr,
376 + prev = maybe_deliver(prev, port, skb, __packet_hook);
380 --- a/net/bridge/br_sysfs_if.c
381 +++ b/net/bridge/br_sysfs_if.c
382 @@ -204,6 +204,7 @@ static BRPORT_ATTR(multicast_router, S_I
383 store_multicast_router);
385 BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
386 +BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UCAST);
389 static const struct brport_attribute *brport_attrs[] = {
390 @@ -230,6 +231,7 @@ static const struct brport_attribute *br
391 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
392 &brport_attr_multicast_router,
393 &brport_attr_multicast_fast_leave,
394 + &brport_attr_multicast_to_unicast,
396 &brport_attr_proxyarp,
397 &brport_attr_proxyarp_wifi,