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net: bridge: mcast: add support for group-and-source specific queries
authorNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Mon, 7 Sep 2020 09:56:09 +0000 (12:56 +0300)
committerJakub Kicinski <kuba@kernel.org>
Mon, 7 Sep 2020 20:16:34 +0000 (13:16 -0700)
Allows br_multicast_alloc_query to build queries with the port group's
source lists and sends a query for sources over and under lmqt when
necessary as per RFCs 3376 and 3810 with the suppress flag set
appropriately.

v3: add IPv6 support

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/bridge/br_multicast.c
net/bridge/br_private.h

index bbfa021..cfb9533 100644 (file)
@@ -234,21 +234,50 @@ out:
 }
 
 static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
-                                                   __be32 group,
-                                                   u8 *igmp_type)
+                                                   struct net_bridge_port_group *pg,
+                                                   __be32 ip_dst, __be32 group,
+                                                   bool with_srcs, bool over_lmqt,
+                                                   u8 sflag, u8 *igmp_type)
 {
+       struct net_bridge_port *p = pg ? pg->port : NULL;
+       struct net_bridge_group_src *ent;
+       size_t pkt_size, igmp_hdr_size;
+       unsigned long now = jiffies;
        struct igmpv3_query *ihv3;
-       size_t igmp_hdr_size;
+       void *csum_start = NULL;
+       __sum16 *csum = NULL;
        struct sk_buff *skb;
        struct igmphdr *ih;
        struct ethhdr *eth;
+       unsigned long lmqt;
        struct iphdr *iph;
+       u16 lmqt_srcs = 0;
 
        igmp_hdr_size = sizeof(*ih);
-       if (br->multicast_igmp_version == 3)
+       if (br->multicast_igmp_version == 3) {
                igmp_hdr_size = sizeof(*ihv3);
-       skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
-                                                igmp_hdr_size + 4);
+               if (pg && with_srcs) {
+                       lmqt = now + (br->multicast_last_member_interval *
+                                     br->multicast_last_member_count);
+                       hlist_for_each_entry(ent, &pg->src_list, node) {
+                               if (over_lmqt == time_after(ent->timer.expires,
+                                                           lmqt) &&
+                                   ent->src_query_rexmit_cnt > 0)
+                                       lmqt_srcs++;
+                       }
+
+                       if (!lmqt_srcs)
+                               return NULL;
+                       igmp_hdr_size += lmqt_srcs * sizeof(__be32);
+               }
+       }
+
+       pkt_size = sizeof(*eth) + sizeof(*iph) + 4 + igmp_hdr_size;
+       if ((p && pkt_size > p->dev->mtu) ||
+           pkt_size > br->dev->mtu)
+               return NULL;
+
+       skb = netdev_alloc_skb_ip_align(br->dev, pkt_size);
        if (!skb)
                goto out;
 
@@ -258,29 +287,24 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
        eth = eth_hdr(skb);
 
        ether_addr_copy(eth->h_source, br->dev->dev_addr);
-       eth->h_dest[0] = 1;
-       eth->h_dest[1] = 0;
-       eth->h_dest[2] = 0x5e;
-       eth->h_dest[3] = 0;
-       eth->h_dest[4] = 0;
-       eth->h_dest[5] = 1;
+       ip_eth_mc_map(ip_dst, eth->h_dest);
        eth->h_proto = htons(ETH_P_IP);
        skb_put(skb, sizeof(*eth));
 
        skb_set_network_header(skb, skb->len);
        iph = ip_hdr(skb);
+       iph->tot_len = htons(pkt_size - sizeof(*eth));
 
        iph->version = 4;
        iph->ihl = 6;
        iph->tos = 0xc0;
-       iph->tot_len = htons(sizeof(*iph) + igmp_hdr_size + 4);
        iph->id = 0;
        iph->frag_off = htons(IP_DF);
        iph->ttl = 1;
        iph->protocol = IPPROTO_IGMP;
        iph->saddr = br_opt_get(br, BROPT_MULTICAST_QUERY_USE_IFADDR) ?
                     inet_select_addr(br->dev, 0, RT_SCOPE_LINK) : 0;
-       iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
+       iph->daddr = ip_dst;
        ((u8 *)&iph[1])[0] = IPOPT_RA;
        ((u8 *)&iph[1])[1] = 4;
        ((u8 *)&iph[1])[2] = 0;
@@ -300,7 +324,8 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
                           (HZ / IGMP_TIMER_SCALE);
                ih->group = group;
                ih->csum = 0;
-               ih->csum = ip_compute_csum((void *)ih, sizeof(*ih));
+               csum = &ih->csum;
+               csum_start = (void *)ih;
                break;
        case 3:
                ihv3 = igmpv3_query_hdr(skb);
@@ -310,15 +335,38 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
                             (HZ / IGMP_TIMER_SCALE);
                ihv3->group = group;
                ihv3->qqic = br->multicast_query_interval / HZ;
-               ihv3->nsrcs = 0;
+               ihv3->nsrcs = htons(lmqt_srcs);
                ihv3->resv = 0;
-               ihv3->suppress = 0;
+               ihv3->suppress = sflag;
                ihv3->qrv = 2;
                ihv3->csum = 0;
-               ihv3->csum = ip_compute_csum((void *)ihv3, sizeof(*ihv3));
+               csum = &ihv3->csum;
+               csum_start = (void *)ihv3;
+               if (!pg || !with_srcs)
+                       break;
+
+               lmqt_srcs = 0;
+               hlist_for_each_entry(ent, &pg->src_list, node) {
+                       if (over_lmqt == time_after(ent->timer.expires,
+                                                   lmqt) &&
+                           ent->src_query_rexmit_cnt > 0) {
+                               ihv3->srcs[lmqt_srcs++] = ent->addr.u.ip4;
+                               ent->src_query_rexmit_cnt--;
+                       }
+               }
+               if (WARN_ON(lmqt_srcs != ntohs(ihv3->nsrcs))) {
+                       kfree_skb(skb);
+                       return NULL;
+               }
                break;
        }
 
+       if (WARN_ON(!csum || !csum_start)) {
+               kfree_skb(skb);
+               return NULL;
+       }
+
+       *csum = ip_compute_csum(csum_start, igmp_hdr_size);
        skb_put(skb, igmp_hdr_size);
        __skb_pull(skb, sizeof(*eth));
 
@@ -328,23 +376,53 @@ out:
 
 #if IS_ENABLED(CONFIG_IPV6)
 static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
-                                                   const struct in6_addr *grp,
-                                                   u8 *igmp_type)
+                                                   struct net_bridge_port_group *pg,
+                                                   const struct in6_addr *ip6_dst,
+                                                   const struct in6_addr *group,
+                                                   bool with_srcs, bool over_llqt,
+                                                   u8 sflag, u8 *igmp_type)
 {
+       struct net_bridge_port *p = pg ? pg->port : NULL;
+       struct net_bridge_group_src *ent;
+       size_t pkt_size, mld_hdr_size;
+       unsigned long now = jiffies;
        struct mld2_query *mld2q;
+       void *csum_start = NULL;
        unsigned long interval;
+       __sum16 *csum = NULL;
        struct ipv6hdr *ip6h;
        struct mld_msg *mldq;
-       size_t mld_hdr_size;
        struct sk_buff *skb;
+       unsigned long llqt;
        struct ethhdr *eth;
+       u16 llqt_srcs = 0;
        u8 *hopopt;
 
        mld_hdr_size = sizeof(*mldq);
-       if (br->multicast_mld_version == 2)
+       if (br->multicast_mld_version == 2) {
                mld_hdr_size = sizeof(*mld2q);
-       skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
-                                                8 + mld_hdr_size);
+               if (pg && with_srcs) {
+                       llqt = now + (br->multicast_last_member_interval *
+                                     br->multicast_last_member_count);
+                       hlist_for_each_entry(ent, &pg->src_list, node) {
+                               if (over_llqt == time_after(ent->timer.expires,
+                                                           llqt) &&
+                                   ent->src_query_rexmit_cnt > 0)
+                                       llqt_srcs++;
+                       }
+
+                       if (!llqt_srcs)
+                               return NULL;
+                       mld_hdr_size += llqt_srcs * sizeof(struct in6_addr);
+               }
+       }
+
+       pkt_size = sizeof(*eth) + sizeof(*ip6h) + 8 + mld_hdr_size;
+       if ((p && pkt_size > p->dev->mtu) ||
+           pkt_size > br->dev->mtu)
+               return NULL;
+
+       skb = netdev_alloc_skb_ip_align(br->dev, pkt_size);
        if (!skb)
                goto out;
 
@@ -366,7 +444,7 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
        ip6h->payload_len = htons(8 + mld_hdr_size);
        ip6h->nexthdr = IPPROTO_HOPOPTS;
        ip6h->hop_limit = 1;
-       ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
+       ip6h->daddr = *ip6_dst;
        if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
                               &ip6h->saddr)) {
                kfree_skb(skb);
@@ -391,7 +469,7 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
 
        /* ICMPv6 */
        skb_set_transport_header(skb, skb->len);
-       interval = ipv6_addr_any(grp) ?
+       interval = ipv6_addr_any(group) ?
                        br->multicast_query_response_interval :
                        br->multicast_last_member_interval;
        *igmp_type = ICMPV6_MGM_QUERY;
@@ -403,12 +481,9 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
                mldq->mld_cksum = 0;
                mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
                mldq->mld_reserved = 0;
-               mldq->mld_mca = *grp;
-               mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
-                                                 sizeof(*mldq), IPPROTO_ICMPV6,
-                                                 csum_partial(mldq,
-                                                              sizeof(*mldq),
-                                                              0));
+               mldq->mld_mca = *group;
+               csum = &mldq->mld_cksum;
+               csum_start = (void *)mldq;
                break;
        case 2:
                mld2q = (struct mld2_query *)icmp6_hdr(skb);
@@ -418,21 +493,41 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
                mld2q->mld2q_cksum = 0;
                mld2q->mld2q_resv1 = 0;
                mld2q->mld2q_resv2 = 0;
-               mld2q->mld2q_suppress = 0;
+               mld2q->mld2q_suppress = sflag;
                mld2q->mld2q_qrv = 2;
-               mld2q->mld2q_nsrcs = 0;
+               mld2q->mld2q_nsrcs = htons(llqt_srcs);
                mld2q->mld2q_qqic = br->multicast_query_interval / HZ;
-               mld2q->mld2q_mca = *grp;
-               mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
-                                                    sizeof(*mld2q),
-                                                    IPPROTO_ICMPV6,
-                                                    csum_partial(mld2q,
-                                                                 sizeof(*mld2q),
-                                                                 0));
+               mld2q->mld2q_mca = *group;
+               csum = &mld2q->mld2q_cksum;
+               csum_start = (void *)mld2q;
+               if (!pg || !with_srcs)
+                       break;
+
+               llqt_srcs = 0;
+               hlist_for_each_entry(ent, &pg->src_list, node) {
+                       if (over_llqt == time_after(ent->timer.expires,
+                                                   llqt) &&
+                           ent->src_query_rexmit_cnt > 0) {
+                               mld2q->mld2q_srcs[llqt_srcs++] = ent->addr.u.ip6;
+                               ent->src_query_rexmit_cnt--;
+                       }
+               }
+               if (WARN_ON(llqt_srcs != ntohs(mld2q->mld2q_nsrcs))) {
+                       kfree_skb(skb);
+                       return NULL;
+               }
                break;
        }
-       skb_put(skb, mld_hdr_size);
 
+       if (WARN_ON(!csum || !csum_start)) {
+               kfree_skb(skb);
+               return NULL;
+       }
+
+       *csum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, mld_hdr_size,
+                               IPPROTO_ICMPV6,
+                               csum_partial(csum_start, mld_hdr_size, 0));
+       skb_put(skb, mld_hdr_size);
        __skb_pull(skb, sizeof(*eth));
 
 out:
@@ -441,16 +536,36 @@ out:
 #endif
 
 static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
-                                               struct br_ip *addr,
-                                               u8 *igmp_type)
+                                               struct net_bridge_port_group *pg,
+                                               struct br_ip *ip_dst,
+                                               struct br_ip *group,
+                                               bool with_srcs, bool over_lmqt,
+                                               u8 sflag, u8 *igmp_type)
 {
-       switch (addr->proto) {
+       __be32 ip4_dst;
+
+       switch (group->proto) {
        case htons(ETH_P_IP):
-               return br_ip4_multicast_alloc_query(br, addr->u.ip4, igmp_type);
+               ip4_dst = ip_dst ? ip_dst->u.ip4 : htonl(INADDR_ALLHOSTS_GROUP);
+               return br_ip4_multicast_alloc_query(br, pg,
+                                                   ip4_dst, group->u.ip4,
+                                                   with_srcs, over_lmqt,
+                                                   sflag, igmp_type);
 #if IS_ENABLED(CONFIG_IPV6)
-       case htons(ETH_P_IPV6):
-               return br_ip6_multicast_alloc_query(br, &addr->u.ip6,
-                                                   igmp_type);
+       case htons(ETH_P_IPV6): {
+               struct in6_addr ip6_dst;
+
+               if (ip_dst)
+                       ip6_dst = ip_dst->u.ip6;
+               else
+                       ipv6_addr_set(&ip6_dst, htonl(0xff020000), 0, 0,
+                                     htonl(1));
+
+               return br_ip6_multicast_alloc_query(br, pg,
+                                                   &ip6_dst, &group->u.ip6,
+                                                   with_srcs, over_lmqt,
+                                                   sflag, igmp_type);
+       }
 #endif
        }
        return NULL;
@@ -824,12 +939,19 @@ static void br_multicast_select_own_querier(struct net_bridge *br,
 
 static void __br_multicast_send_query(struct net_bridge *br,
                                      struct net_bridge_port *port,
-                                     struct br_ip *ip)
+                                     struct net_bridge_port_group *pg,
+                                     struct br_ip *ip_dst,
+                                     struct br_ip *group,
+                                     bool with_srcs,
+                                     u8 sflag)
 {
+       bool over_lmqt = !!sflag;
        struct sk_buff *skb;
        u8 igmp_type;
 
-       skb = br_multicast_alloc_query(br, ip, &igmp_type);
+again_under_lmqt:
+       skb = br_multicast_alloc_query(br, pg, ip_dst, group, with_srcs,
+                                      over_lmqt, sflag, &igmp_type);
        if (!skb)
                return;
 
@@ -840,8 +962,13 @@ static void __br_multicast_send_query(struct net_bridge *br,
                NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT,
                        dev_net(port->dev), NULL, skb, NULL, skb->dev,
                        br_dev_queue_push_xmit);
+
+               if (over_lmqt && with_srcs && sflag) {
+                       over_lmqt = false;
+                       goto again_under_lmqt;
+               }
        } else {
-               br_multicast_select_own_querier(br, ip, skb);
+               br_multicast_select_own_querier(br, group, skb);
                br_multicast_count(br, port, skb, igmp_type,
                                   BR_MCAST_DIR_RX);
                netif_rx(skb);
@@ -877,7 +1004,7 @@ static void br_multicast_send_query(struct net_bridge *br,
        if (!other_query || timer_pending(&other_query->timer))
                return;
 
-       __br_multicast_send_query(br, port, &br_group);
+       __br_multicast_send_query(br, port, NULL, NULL, &br_group, false, 0);
 
        time = jiffies;
        time += own_query->startup_sent < br->multicast_startup_query_count ?
@@ -1530,7 +1657,8 @@ br_multicast_leave_group(struct net_bridge *br,
                goto out;
 
        if (br_opt_get(br, BROPT_MULTICAST_QUERIER)) {
-               __br_multicast_send_query(br, port, &mp->addr);
+               __br_multicast_send_query(br, port, NULL, NULL, &mp->addr,
+                                         false, 0);
 
                time = jiffies + br->multicast_last_member_count *
                                 br->multicast_last_member_interval;
index eab8952..e063272 100644 (file)
@@ -225,6 +225,7 @@ struct net_bridge_group_src {
        struct br_ip                    addr;
        struct net_bridge_port_group    *pg;
        u8                              flags;
+       u8                              src_query_rexmit_cnt;
        struct timer_list               timer;
 
        struct net_bridge               *br;