Allows br_ip4_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 RFC 3376 with the suppress flag set appropriately.

Signed-off-by: Nikolay Aleksandrov <niko...@cumulusnetworks.com>
---
 net/bridge/br_multicast.c | 126 +++++++++++++++++++++++++++++---------
 net/bridge/br_private.h   |   1 +
 2 files changed, 99 insertions(+), 28 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 9269d62884e5..8a415672764a 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -228,21 +228,50 @@ static void br_multicast_port_group_expired(struct 
timer_list *t)
 }
 
 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;
 
@@ -252,29 +281,24 @@ 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;
@@ -294,7 +318,8 @@ 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);
@@ -304,15 +329,38 @@ 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);
+               return NULL;
+       }
+
+       *csum = ip_compute_csum(csum_start, igmp_hdr_size);
        skb_put(skb, igmp_hdr_size);
        __skb_pull(skb, sizeof(*eth));
 
@@ -435,15 +483,24 @@ static struct sk_buff 
*br_ip6_multicast_alloc_query(struct net_bridge *br,
 #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,
+               return br_ip6_multicast_alloc_query(br, &group->u.ip6,
                                                    igmp_type);
 #endif
        }
@@ -808,12 +865,19 @@ 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;
 
@@ -824,8 +888,13 @@ 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);
@@ -861,7 +930,7 @@ 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 ?
@@ -1522,7 +1591,8 @@ 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;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 311ad0e402dc..87610d6c0b3f 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -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;
-- 
2.25.4

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