OpenWrt – Blame information for rev 3

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1 office 1 From: Felix Fietkau <nbd@nbd.name>
2 Date: Thu, 19 Jan 2017 03:45:10 +0100
3 Subject: [PATCH] bridge: multicast to unicast
4 MIME-Version: 1.0
5 Content-Type: text/plain; charset=UTF-8
6 Content-Transfer-Encoding: 8bit
7  
8 Implements an optional, per bridge port flag and feature to deliver
9 multicast packets to any host on the according port via unicast
10 individually. This is done by copying the packet per host and
11 changing the multicast destination MAC to a unicast one accordingly.
12  
13 multicast-to-unicast works on top of the multicast snooping feature of
14 the bridge. Which means unicast copies are only delivered to hosts which
15 are interested in it and signalized this via IGMP/MLD reports
16 previously.
17  
18 This feature is intended for interface types which have a more reliable
19 and/or efficient way to deliver unicast packets than broadcast ones
20 (e.g. wifi).
21  
22 However, it should only be enabled on interfaces where no IGMPv2/MLDv1
23 report suppression takes place. This feature is disabled by default.
24  
25 The initial patch and idea is from Felix Fietkau.
26  
27 Signed-off-by: Felix Fietkau <nbd@nbd.name>
28 [linus.luessing@c0d3.blue: various bug + style fixes, commit message]
29 Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
30 ---
31  
32 --- a/include/linux/if_bridge.h
33 +++ b/include/linux/if_bridge.h
34 @@ -46,6 +46,7 @@ struct br_ip_list {
35 #define BR_LEARNING_SYNC BIT(9)
36 #define BR_PROXYARP_WIFI BIT(10)
37 #define BR_MCAST_FLOOD BIT(11)
38 +#define BR_MULTICAST_TO_UNICAST BIT(12)
39  
40 #define BR_DEFAULT_AGEING_TIME (300 * HZ)
41  
42 --- a/include/uapi/linux/if_link.h
43 +++ b/include/uapi/linux/if_link.h
44 @@ -319,6 +319,7 @@ enum {
45 IFLA_BRPORT_MULTICAST_ROUTER,
46 IFLA_BRPORT_PAD,
47 IFLA_BRPORT_MCAST_FLOOD,
48 + IFLA_BRPORT_MCAST_TO_UCAST,
49 __IFLA_BRPORT_MAX
50 };
51 #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)
52 --- a/net/bridge/br_forward.c
53 +++ b/net/bridge/br_forward.c
3 office 54 @@ -174,6 +174,29 @@ out:
1 office 55 return p;
56 }
57  
58 +static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb,
59 + const unsigned char *addr, bool local_orig)
60 +{
61 + struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
62 + const unsigned char *src = eth_hdr(skb)->h_source;
63 +
64 + if (!should_deliver(p, skb))
65 + return;
66 +
67 + /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */
68 + if (skb->dev == p->dev && ether_addr_equal(src, addr))
69 + return;
70 +
71 + skb = skb_copy(skb, GFP_ATOMIC);
72 + if (!skb) {
73 + dev->stats.tx_dropped++;
74 + return;
75 + }
76 +
77 + memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
78 + __br_forward(p, skb, local_orig);
79 +}
80 +
81 /* called under rcu_read_lock */
82 void br_flood(struct net_bridge *br, struct sk_buff *skb,
83 enum br_pkt_type pkt_type, bool local_rcv, bool local_orig)
3 office 84 @@ -242,10 +265,20 @@ void br_multicast_flood(struct net_bridg
1 office 85 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
86 NULL;
87  
88 - port = (unsigned long)lport > (unsigned long)rport ?
89 - lport : rport;
90 + if ((unsigned long)lport > (unsigned long)rport) {
91 + port = lport;
92 +
93 + if (p->flags & MDB_PG_FLAGS_MCAST_TO_UCAST) {
94 + maybe_deliver_addr(lport, skb, p->eth_addr,
95 + local_orig);
96 + goto delivered;
97 + }
98 + } else {
99 + port = rport;
100 + }
101  
102 prev = maybe_deliver(prev, port, skb, local_orig);
103 +delivered:
104 if (IS_ERR(prev))
105 goto out;
106 if (prev == port)
107 --- a/net/bridge/br_mdb.c
108 +++ b/net/bridge/br_mdb.c
109 @@ -532,7 +532,7 @@ static int br_mdb_add_group(struct net_b
110 break;
111 }
112  
113 - p = br_multicast_new_port_group(port, group, *pp, state);
114 + p = br_multicast_new_port_group(port, group, *pp, state, NULL);
115 if (unlikely(!p))
116 return -ENOMEM;
117 rcu_assign_pointer(*pp, p);
118 --- a/net/bridge/br_multicast.c
119 +++ b/net/bridge/br_multicast.c
120 @@ -42,12 +42,14 @@ static void br_multicast_add_router(stru
121 static void br_ip4_multicast_leave_group(struct net_bridge *br,
122 struct net_bridge_port *port,
123 __be32 group,
124 - __u16 vid);
125 + __u16 vid,
126 + const unsigned char *src);
127 +
128 #if IS_ENABLED(CONFIG_IPV6)
129 static void br_ip6_multicast_leave_group(struct net_bridge *br,
130 struct net_bridge_port *port,
131 const struct in6_addr *group,
132 - __u16 vid);
133 + __u16 vid, const unsigned char *src);
134 #endif
135 unsigned int br_mdb_rehash_seq;
136  
137 @@ -658,7 +660,8 @@ struct net_bridge_port_group *br_multica
138 struct net_bridge_port *port,
139 struct br_ip *group,
140 struct net_bridge_port_group __rcu *next,
141 - unsigned char flags)
142 + unsigned char flags,
143 + const unsigned char *src)
144 {
145 struct net_bridge_port_group *p;
146  
147 @@ -673,12 +676,39 @@ struct net_bridge_port_group *br_multica
148 hlist_add_head(&p->mglist, &port->mglist);
149 setup_timer(&p->timer, br_multicast_port_group_expired,
150 (unsigned long)p);
151 +
152 + if ((port->flags & BR_MULTICAST_TO_UNICAST) && src) {
153 + memcpy(p->eth_addr, src, ETH_ALEN);
154 + p->flags |= MDB_PG_FLAGS_MCAST_TO_UCAST;
155 + }
156 +
157 return p;
158 }
159  
160 +static bool br_port_group_equal(struct net_bridge_port_group *p,
161 + struct net_bridge_port *port,
162 + const unsigned char *src)
163 +{
164 + if (p->port != port)
165 + return false;
166 +
167 + if (!(p->flags & MDB_PG_FLAGS_MCAST_TO_UCAST) !=
168 + !(port->flags & BR_MULTICAST_TO_UNICAST))
169 + return false;
170 +
171 + if (!(p->flags & MDB_PG_FLAGS_MCAST_TO_UCAST))
172 + return true;
173 +
174 + if (!src)
175 + return false;
176 +
177 + return ether_addr_equal(src, p->eth_addr);
178 +}
179 +
180 static int br_multicast_add_group(struct net_bridge *br,
181 struct net_bridge_port *port,
182 - struct br_ip *group)
183 + struct br_ip *group,
184 + const unsigned char *src)
185 {
186 struct net_bridge_mdb_entry *mp;
187 struct net_bridge_port_group *p;
188 @@ -705,13 +735,13 @@ static int br_multicast_add_group(struct
189 for (pp = &mp->ports;
190 (p = mlock_dereference(*pp, br)) != NULL;
191 pp = &p->next) {
192 - if (p->port == port)
193 + if (br_port_group_equal(p, port, src))
194 goto found;
195 if ((unsigned long)p->port < (unsigned long)port)
196 break;
197 }
198  
199 - p = br_multicast_new_port_group(port, group, *pp, 0);
200 + p = br_multicast_new_port_group(port, group, *pp, 0, src);
201 if (unlikely(!p))
202 goto err;
203 rcu_assign_pointer(*pp, p);
204 @@ -730,7 +760,8 @@ err:
205 static int br_ip4_multicast_add_group(struct net_bridge *br,
206 struct net_bridge_port *port,
207 __be32 group,
208 - __u16 vid)
209 + __u16 vid,
210 + const unsigned char *src)
211 {
212 struct br_ip br_group;
213  
214 @@ -741,14 +772,15 @@ static int br_ip4_multicast_add_group(st
215 br_group.proto = htons(ETH_P_IP);
216 br_group.vid = vid;
217  
218 - return br_multicast_add_group(br, port, &br_group);
219 + return br_multicast_add_group(br, port, &br_group, src);
220 }
221  
222 #if IS_ENABLED(CONFIG_IPV6)
223 static int br_ip6_multicast_add_group(struct net_bridge *br,
224 struct net_bridge_port *port,
225 const struct in6_addr *group,
226 - __u16 vid)
227 + __u16 vid,
228 + const unsigned char *src)
229 {
230 struct br_ip br_group;
231  
232 @@ -759,7 +791,7 @@ static int br_ip6_multicast_add_group(st
233 br_group.proto = htons(ETH_P_IPV6);
234 br_group.vid = vid;
235  
236 - return br_multicast_add_group(br, port, &br_group);
237 + return br_multicast_add_group(br, port, &br_group, src);
238 }
239 #endif
240  
241 @@ -1028,6 +1060,7 @@ static int br_ip4_multicast_igmp3_report
242 struct sk_buff *skb,
243 u16 vid)
244 {
245 + const unsigned char *src;
246 struct igmpv3_report *ih;
247 struct igmpv3_grec *grec;
248 int i;
249 @@ -1068,12 +1101,14 @@ static int br_ip4_multicast_igmp3_report
250 continue;
251 }
252  
253 + src = eth_hdr(skb)->h_source;
254 if ((type == IGMPV3_CHANGE_TO_INCLUDE ||
255 type == IGMPV3_MODE_IS_INCLUDE) &&
256 ntohs(grec->grec_nsrcs) == 0) {
257 - br_ip4_multicast_leave_group(br, port, group, vid);
258 + br_ip4_multicast_leave_group(br, port, group, vid, src);
259 } else {
260 - err = br_ip4_multicast_add_group(br, port, group, vid);
261 + err = br_ip4_multicast_add_group(br, port, group, vid,
262 + src);
263 if (err)
264 break;
265 }
266 @@ -1088,6 +1123,7 @@ static int br_ip6_multicast_mld2_report(
267 struct sk_buff *skb,
268 u16 vid)
269 {
270 + const unsigned char *src = eth_hdr(skb)->h_source;
271 struct icmp6hdr *icmp6h;
272 struct mld2_grec *grec;
273 int i;
274 @@ -1139,10 +1175,11 @@ static int br_ip6_multicast_mld2_report(
275 grec->grec_type == MLD2_MODE_IS_INCLUDE) &&
276 ntohs(*nsrcs) == 0) {
277 br_ip6_multicast_leave_group(br, port, &grec->grec_mca,
278 - vid);
279 + vid, src);
280 } else {
281 err = br_ip6_multicast_add_group(br, port,
282 - &grec->grec_mca, vid);
283 + &grec->grec_mca, vid,
284 + src);
285 if (err)
286 break;
287 }
3 office 288 @@ -1458,7 +1495,8 @@ br_multicast_leave_group(struct net_brid
1 office 289 struct net_bridge_port *port,
290 struct br_ip *group,
291 struct bridge_mcast_other_query *other_query,
292 - struct bridge_mcast_own_query *own_query)
293 + struct bridge_mcast_own_query *own_query,
294 + const unsigned char *src)
295 {
296 struct net_bridge_mdb_htable *mdb;
297 struct net_bridge_mdb_entry *mp;
3 office 298 @@ -1482,7 +1520,7 @@ br_multicast_leave_group(struct net_brid
1 office 299 for (pp = &mp->ports;
300 (p = mlock_dereference(*pp, br)) != NULL;
301 pp = &p->next) {
302 - if (p->port != port)
303 + if (!br_port_group_equal(p, port, src))
304 continue;
305  
306 rcu_assign_pointer(*pp, p->next);
3 office 307 @@ -1513,7 +1551,7 @@ br_multicast_leave_group(struct net_brid
1 office 308 for (p = mlock_dereference(mp->ports, br);
309 p != NULL;
310 p = mlock_dereference(p->next, br)) {
311 - if (p->port != port)
312 + if (!br_port_group_equal(p, port, src))
313 continue;
314  
315 if (!hlist_unhashed(&p->mglist) &&
3 office 316 @@ -1564,7 +1602,8 @@ out:
1 office 317 static void br_ip4_multicast_leave_group(struct net_bridge *br,
318 struct net_bridge_port *port,
319 __be32 group,
320 - __u16 vid)
321 + __u16 vid,
322 + const unsigned char *src)
323 {
324 struct br_ip br_group;
325 struct bridge_mcast_own_query *own_query;
3 office 326 @@ -1579,14 +1618,15 @@ static void br_ip4_multicast_leave_group
1 office 327 br_group.vid = vid;
328  
329 br_multicast_leave_group(br, port, &br_group, &br->ip4_other_query,
330 - own_query);
331 + own_query, src);
332 }
333  
334 #if IS_ENABLED(CONFIG_IPV6)
335 static void br_ip6_multicast_leave_group(struct net_bridge *br,
336 struct net_bridge_port *port,
337 const struct in6_addr *group,
338 - __u16 vid)
339 + __u16 vid,
340 + const unsigned char *src)
341 {
342 struct br_ip br_group;
343 struct bridge_mcast_own_query *own_query;
3 office 344 @@ -1601,7 +1641,7 @@ static void br_ip6_multicast_leave_group
1 office 345 br_group.vid = vid;
346  
347 br_multicast_leave_group(br, port, &br_group, &br->ip6_other_query,
348 - own_query);
349 + own_query, src);
350 }
351 #endif
352  
3 office 353 @@ -1644,6 +1684,7 @@ static int br_multicast_ipv4_rcv(struct
1 office 354 u16 vid)
355 {
356 struct sk_buff *skb_trimmed = NULL;
357 + const unsigned char *src;
358 struct igmphdr *ih;
359 int err;
360  
3 office 361 @@ -1659,13 +1700,14 @@ static int br_multicast_ipv4_rcv(struct
1 office 362 }
363  
364 ih = igmp_hdr(skb);
365 + src = eth_hdr(skb)->h_source;
366 BR_INPUT_SKB_CB(skb)->igmp = ih->type;
367  
368 switch (ih->type) {
369 case IGMP_HOST_MEMBERSHIP_REPORT:
370 case IGMPV2_HOST_MEMBERSHIP_REPORT:
371 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
372 - err = br_ip4_multicast_add_group(br, port, ih->group, vid);
373 + err = br_ip4_multicast_add_group(br, port, ih->group, vid, src);
374 break;
375 case IGMPV3_HOST_MEMBERSHIP_REPORT:
376 err = br_ip4_multicast_igmp3_report(br, port, skb_trimmed, vid);
3 office 377 @@ -1674,7 +1716,7 @@ static int br_multicast_ipv4_rcv(struct
1 office 378 err = br_ip4_multicast_query(br, port, skb_trimmed, vid);
379 break;
380 case IGMP_HOST_LEAVE_MESSAGE:
381 - br_ip4_multicast_leave_group(br, port, ih->group, vid);
382 + br_ip4_multicast_leave_group(br, port, ih->group, vid, src);
383 break;
384 }
385  
3 office 386 @@ -1694,6 +1736,7 @@ static int br_multicast_ipv6_rcv(struct
1 office 387 u16 vid)
388 {
389 struct sk_buff *skb_trimmed = NULL;
390 + const unsigned char *src;
391 struct mld_msg *mld;
392 int err;
393  
3 office 394 @@ -1713,8 +1756,10 @@ static int br_multicast_ipv6_rcv(struct
1 office 395  
396 switch (mld->mld_type) {
397 case ICMPV6_MGM_REPORT:
398 + src = eth_hdr(skb)->h_source;
399 BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
400 - err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid);
401 + err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid,
402 + src);
403 break;
404 case ICMPV6_MLD2_REPORT:
405 err = br_ip6_multicast_mld2_report(br, port, skb_trimmed, vid);
3 office 406 @@ -1723,7 +1768,8 @@ static int br_multicast_ipv6_rcv(struct
1 office 407 err = br_ip6_multicast_query(br, port, skb_trimmed, vid);
408 break;
409 case ICMPV6_MGM_REDUCTION:
410 - br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid);
411 + src = eth_hdr(skb)->h_source;
412 + br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid, src);
413 break;
414 }
415  
416 --- a/net/bridge/br_netlink.c
417 +++ b/net/bridge/br_netlink.c
418 @@ -123,6 +123,7 @@ static inline size_t br_port_info_size(v
419 + nla_total_size(1) /* IFLA_BRPORT_GUARD */
420 + nla_total_size(1) /* IFLA_BRPORT_PROTECT */
421 + nla_total_size(1) /* IFLA_BRPORT_FAST_LEAVE */
422 + + nla_total_size(1) /* IFLA_BRPORT_MCAST_TO_UCAST */
423 + nla_total_size(1) /* IFLA_BRPORT_LEARNING */
424 + nla_total_size(1) /* IFLA_BRPORT_UNICAST_FLOOD */
425 + nla_total_size(1) /* IFLA_BRPORT_PROXYARP */
426 @@ -173,6 +174,8 @@ static int br_port_fill_attrs(struct sk_
427 !!(p->flags & BR_ROOT_BLOCK)) ||
428 nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE,
429 !!(p->flags & BR_MULTICAST_FAST_LEAVE)) ||
430 + nla_put_u8(skb, IFLA_BRPORT_MCAST_TO_UCAST,
431 + !!(p->flags & BR_MULTICAST_TO_UNICAST)) ||
432 nla_put_u8(skb, IFLA_BRPORT_LEARNING, !!(p->flags & BR_LEARNING)) ||
433 nla_put_u8(skb, IFLA_BRPORT_UNICAST_FLOOD,
434 !!(p->flags & BR_FLOOD)) ||
435 @@ -586,6 +589,7 @@ static const struct nla_policy br_port_p
436 [IFLA_BRPORT_PROXYARP] = { .type = NLA_U8 },
437 [IFLA_BRPORT_PROXYARP_WIFI] = { .type = NLA_U8 },
438 [IFLA_BRPORT_MULTICAST_ROUTER] = { .type = NLA_U8 },
439 + [IFLA_BRPORT_MCAST_TO_UCAST] = { .type = NLA_U8 },
440 };
441  
442 /* Change the state of the port and notify spanning tree */
443 @@ -636,6 +640,7 @@ static int br_setport(struct net_bridge_
444 br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
445 br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
446 br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_FLOOD, BR_MCAST_FLOOD);
447 + br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_TO_UCAST, BR_MULTICAST_TO_UNICAST);
448 br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
449 br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
450  
451 --- a/net/bridge/br_private.h
452 +++ b/net/bridge/br_private.h
453 @@ -166,8 +166,9 @@ struct net_bridge_fdb_entry
454 struct rcu_head rcu;
455 };
456  
457 -#define MDB_PG_FLAGS_PERMANENT BIT(0)
458 -#define MDB_PG_FLAGS_OFFLOAD BIT(1)
459 +#define MDB_PG_FLAGS_PERMANENT BIT(0)
460 +#define MDB_PG_FLAGS_OFFLOAD BIT(1)
461 +#define MDB_PG_FLAGS_MCAST_TO_UCAST BIT(2)
462  
463 struct net_bridge_port_group {
464 struct net_bridge_port *port;
465 @@ -177,6 +178,7 @@ struct net_bridge_port_group {
466 struct timer_list timer;
467 struct br_ip addr;
468 unsigned char flags;
469 + unsigned char eth_addr[ETH_ALEN];
470 };
471  
472 struct net_bridge_mdb_entry
473 @@ -591,7 +593,7 @@ void br_multicast_free_pg(struct rcu_hea
474 struct net_bridge_port_group *
475 br_multicast_new_port_group(struct net_bridge_port *port, struct br_ip *group,
476 struct net_bridge_port_group __rcu *next,
477 - unsigned char flags);
478 + unsigned char flags, const unsigned char *src);
479 void br_mdb_init(void);
480 void br_mdb_uninit(void);
481 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
482 --- a/net/bridge/br_sysfs_if.c
483 +++ b/net/bridge/br_sysfs_if.c
484 @@ -188,6 +188,7 @@ static BRPORT_ATTR(multicast_router, S_I
485 store_multicast_router);
486  
487 BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
488 +BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UNICAST);
489 #endif
490  
491 static const struct brport_attribute *brport_attrs[] = {
492 @@ -214,6 +215,7 @@ static const struct brport_attribute *br
493 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
494 &brport_attr_multicast_router,
495 &brport_attr_multicast_fast_leave,
496 + &brport_attr_multicast_to_unicast,
497 #endif
498 &brport_attr_proxyarp,
499 &brport_attr_proxyarp_wifi,