target/linux/generic/backport-4.9/021-bridge-multicast-to-unicast.patch

   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 LÃ¼ssing <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
  54 @@ -174,6 +174,29 @@ out:
  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)
  84 @@ -242,10 +265,20 @@ void br_multicast_flood(struct net_bridg
  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                 }
 288 @@ -1458,7 +1495,8 @@ br_multicast_leave_group(struct net_brid
 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;
 298 @@ -1482,7 +1520,7 @@ br_multicast_leave_group(struct net_brid
 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);
 307 @@ -1513,7 +1551,7 @@ br_multicast_leave_group(struct net_brid
 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) &&
 316 @@ -1564,7 +1602,8 @@ out:
 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;
 326 @@ -1579,14 +1618,15 @@ static void br_ip4_multicast_leave_group
 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;
 344 @@ -1601,7 +1641,7 @@ static void br_ip6_multicast_leave_group
 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
 353 @@ -1644,6 +1684,7 @@ static int br_multicast_ipv4_rcv(struct
 354                                  u16 vid)
 355  {
 356         struct sk_buff *skb_trimmed = NULL;
 357 +       const unsigned char *src;
 358         struct igmphdr *ih;
 359         int err;
 360
 361 @@ -1659,13 +1700,14 @@ static int br_multicast_ipv4_rcv(struct
 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);
 377 @@ -1674,7 +1716,7 @@ static int br_multicast_ipv4_rcv(struct
 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
 386 @@ -1694,6 +1736,7 @@ static int br_multicast_ipv6_rcv(struct
 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
 394 @@ -1713,8 +1756,10 @@ static int br_multicast_ipv6_rcv(struct
 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);
 406 @@ -1723,7 +1768,8 @@ static int br_multicast_ipv6_rcv(struct
 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,