bridge br_multicast: IPv6 MLD support.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

3 files changed, 429 insertions, 4 deletions

diff --git a/net/bridge/Kconfig b/net/bridge/Kconfig
index d115d5cea5b6..9190ae462cb4 100644
--- a/net/bridge/Kconfig
+++ b/net/bridge/Kconfig
@@ -33,14 +33,14 @@ config BRIDGE
           If unsure, say N.
 
 config BRIDGE_IGMP_SNOOPING
-        bool "IGMP snooping"
+        bool "IGMP/MLD snooping"
         depends on BRIDGE
         depends on INET
         default y
         ---help---
           If you say Y here, then the Ethernet bridge will be able selectively
-          forward multicast traffic based on IGMP traffic received from each
-          port.
+          forward multicast traffic based on IGMP/MLD traffic received from
+          each port.
 
           Say N to exclude this support and reduce the binary size.
 
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 64a3e4f74348..38d1fbde5fb8 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -24,9 +24,24 @@
 #include <linux/slab.h>
 #include <linux/timer.h>
 #include <net/ip.h>
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+#include <net/ipv6.h>
+#include <net/mld.h>
+#include <net/addrconf.h>
+#endif
 
 #include "br_private.h"
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static inline int ipv6_is_local_multicast(const struct in6_addr *addr)
+{
+        if (ipv6_addr_is_multicast(addr) &&
+            IPV6_ADDR_MC_SCOPE(addr) <= IPV6_ADDR_SCOPE_LINKLOCAL)
+                return 1;
+        return 0;
+}
+#endif
+
 static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
 {
         if (a->proto != b->proto)
@@ -34,6 +49,10 @@ static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
         switch (a->proto) {
         case htons(ETH_P_IP):
                 return a->u.ip4 == b->u.ip4;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case htons(ETH_P_IPV6):
+                return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
+#endif
         }
         return 0;
 }
@@ -43,12 +62,24 @@ static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
         return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
+                                const struct in6_addr *ip)
+{
+        return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
+}
+#endif
+
 static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
                              struct br_ip *ip)
 {
         switch (ip->proto) {
         case htons(ETH_P_IP):
                 return __br_ip4_hash(mdb, ip->u.ip4);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case htons(ETH_P_IPV6):
+                return __br_ip6_hash(mdb, &ip->u.ip6);
+#endif
         }
         return 0;
 }
@@ -78,6 +109,19 @@ static struct net_bridge_mdb_entry *br_mdb_ip4_get(
         return __br_mdb_ip_get(mdb, &br_dst, __br_ip4_hash(mdb, dst));
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static struct net_bridge_mdb_entry *br_mdb_ip6_get(
+        struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
+{
+        struct br_ip br_dst;
+
+        ipv6_addr_copy(&br_dst.u.ip6, dst);
+        br_dst.proto = htons(ETH_P_IPV6);
+
+        return __br_mdb_ip_get(mdb, &br_dst, __br_ip6_hash(mdb, dst));
+}
+#endif
+
 static struct net_bridge_mdb_entry *br_mdb_ip_get(
         struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
 {
@@ -102,6 +146,11 @@ struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
         case htons(ETH_P_IP):
                 ip.u.ip4 = ip_hdr(skb)->daddr;
                 break;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case htons(ETH_P_IPV6):
+                ipv6_addr_copy(&ip.u.ip6, &ipv6_hdr(skb)->daddr);
+                break;
+#endif
         default:
                 return NULL;
         }
@@ -352,12 +401,94 @@ out:
         return skb;
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
+                                                    struct in6_addr *group)
+{
+        struct sk_buff *skb;
+        struct ipv6hdr *ip6h;
+        struct mld_msg *mldq;
+        struct ethhdr *eth;
+        u8 *hopopt;
+        unsigned long interval;
+
+        skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
+                                                 8 + sizeof(*mldq));
+        if (!skb)
+                goto out;
+
+        skb->protocol = htons(ETH_P_IPV6);
+
+        /* Ethernet header */
+        skb_reset_mac_header(skb);
+        eth = eth_hdr(skb);
+
+        memcpy(eth->h_source, br->dev->dev_addr, 6);
+        ipv6_eth_mc_map(group, eth->h_dest);
+        eth->h_proto = htons(ETH_P_IPV6);
+        skb_put(skb, sizeof(*eth));
+
+        /* IPv6 header + HbH option */
+        skb_set_network_header(skb, skb->len);
+        ip6h = ipv6_hdr(skb);
+
+        *(__force __be32 *)ip6h = htonl(0x60000000);
+        ip6h->payload_len = 8 + sizeof(*mldq);
+        ip6h->nexthdr = IPPROTO_HOPOPTS;
+        ip6h->hop_limit = 1;
+        ipv6_addr_set(&ip6h->saddr, 0, 0, 0, 0);
+        ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
+
+        hopopt = (u8 *)(ip6h + 1);
+        hopopt[0] = IPPROTO_ICMPV6;             /* next hdr */
+        hopopt[1] = 0;                          /* length of HbH */
+        hopopt[2] = IPV6_TLV_ROUTERALERT;       /* Router Alert */
+        hopopt[3] = 2;                          /* Length of RA Option */
+        hopopt[4] = 0;                          /* Type = 0x0000 (MLD) */
+        hopopt[5] = 0;
+        hopopt[6] = IPV6_TLV_PAD0;              /* Pad0 */
+        hopopt[7] = IPV6_TLV_PAD0;              /* Pad0 */
+
+        skb_put(skb, sizeof(*ip6h) + 8);
+
+        /* ICMPv6 */
+        skb_set_transport_header(skb, skb->len);
+        mldq = (struct mld_msg *) icmp6_hdr(skb);
+
+        interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
+                                          br->multicast_query_response_interval;
+
+        mldq->mld_type = ICMPV6_MGM_QUERY;
+        mldq->mld_code = 0;
+        mldq->mld_cksum = 0;
+        mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
+        mldq->mld_reserved = 0;
+        ipv6_addr_copy(&mldq->mld_mca, group);
+
+        /* checksum */
+        mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+                                          sizeof(*mldq), IPPROTO_ICMPV6,
+                                          csum_partial(mldq,
+                                                       sizeof(*mldq), 0));
+        skb_put(skb, sizeof(*mldq));
+
+        __skb_pull(skb, sizeof(*eth));
+
+out:
+        return skb;
+}
+#endif
+
 static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
                                                 struct br_ip *addr)
 {
         switch (addr->proto) {
         case htons(ETH_P_IP):
                 return br_ip4_multicast_alloc_query(br, addr->u.ip4);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case htons(ETH_P_IPV6):
+                return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
+#endif
         }
         return NULL;
 }
@@ -631,6 +762,23 @@ static int br_ip4_multicast_add_group(struct net_bridge *br,
         return br_multicast_add_group(br, port, &br_group);
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static int br_ip6_multicast_add_group(struct net_bridge *br,
+                                      struct net_bridge_port *port,
+                                      const struct in6_addr *group)
+{
+        struct br_ip br_group;
+
+        if (ipv6_is_local_multicast(group))
+                return 0;
+
+        ipv6_addr_copy(&br_group.u.ip6, group);
+        br_group.proto = htons(ETH_P_IP);
+
+        return br_multicast_add_group(br, port, &br_group);
+}
+#endif
+
 static void br_multicast_router_expired(unsigned long data)
 {
         struct net_bridge_port *port = (void *)data;
@@ -681,10 +829,15 @@ static void br_multicast_send_query(struct net_bridge *br,
             timer_pending(&br->multicast_querier_timer))
                 return;
 
-        br_group.u.ip4 = 0;
+        memset(&br_group.u, 0, sizeof(br_group.u));
+
         br_group.proto = htons(ETH_P_IP);
+        __br_multicast_send_query(br, port, &br_group);
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        br_group.proto = htons(ETH_P_IPV6);
         __br_multicast_send_query(br, port, &br_group);
+#endif
 
         time = jiffies;
         time += sent < br->multicast_startup_query_count ?
@@ -825,6 +978,66 @@ static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
         return err;
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static int br_ip6_multicast_mld2_report(struct net_bridge *br,
+                                        struct net_bridge_port *port,
+                                        struct sk_buff *skb)
+{
+        struct icmp6hdr *icmp6h;
+        struct mld2_grec *grec;
+        int i;
+        int len;
+        int num;
+        int err = 0;
+
+        if (!pskb_may_pull(skb, sizeof(*icmp6h)))
+                return -EINVAL;
+
+        icmp6h = icmp6_hdr(skb);
+        num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
+        len = sizeof(*icmp6h);
+
+        for (i = 0; i < num; i++) {
+                __be16 *nsrcs, _nsrcs;
+
+                nsrcs = skb_header_pointer(skb,
+                                           len + offsetof(struct mld2_grec,
+                                                          grec_mca),
+                                           sizeof(_nsrcs), &_nsrcs);
+                if (!nsrcs)
+                        return -EINVAL;
+
+                if (!pskb_may_pull(skb,
+                                   len + sizeof(*grec) +
+                                   sizeof(struct in6_addr) * (*nsrcs)))
+                        return -EINVAL;
+
+                grec = (struct mld2_grec *)(skb->data + len);
+                len += sizeof(*grec) + sizeof(struct in6_addr) * (*nsrcs);
+
+                /* We treat these as MLDv1 reports for now. */
+                switch (grec->grec_type) {
+                case MLD2_MODE_IS_INCLUDE:
+                case MLD2_MODE_IS_EXCLUDE:
+                case MLD2_CHANGE_TO_INCLUDE:
+                case MLD2_CHANGE_TO_EXCLUDE:
+                case MLD2_ALLOW_NEW_SOURCES:
+                case MLD2_BLOCK_OLD_SOURCES:
+                        break;
+
+                default:
+                        continue;
+                }
+
+                err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
+                if (!err)
+                        break;
+        }
+
+        return err;
+}
+#endif
+
 static void br_multicast_add_router(struct net_bridge *br,
                                     struct net_bridge_port *port)
 {
@@ -955,6 +1168,75 @@ out:
         return err;
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static int br_ip6_multicast_query(struct net_bridge *br,
+                                  struct net_bridge_port *port,
+                                  struct sk_buff *skb)
+{
+        struct ipv6hdr *ip6h = ipv6_hdr(skb);
+        struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
+        struct net_bridge_mdb_entry *mp;
+        struct mld2_query *mld2q;
+        struct net_bridge_port_group *p, **pp;
+        unsigned long max_delay;
+        unsigned long now = jiffies;
+        struct in6_addr *group = NULL;
+        int err = 0;
+
+        spin_lock(&br->multicast_lock);
+        if (!netif_running(br->dev) ||
+            (port && port->state == BR_STATE_DISABLED))
+                goto out;
+
+        br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
+
+        if (skb->len == sizeof(*mld)) {
+                if (!pskb_may_pull(skb, sizeof(*mld))) {
+                        err = -EINVAL;
+                        goto out;
+                }
+                mld = (struct mld_msg *) icmp6_hdr(skb);
+                max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay));
+                if (max_delay)
+                        group = &mld->mld_mca;
+        } else if (skb->len >= sizeof(*mld2q)) {
+                if (!pskb_may_pull(skb, sizeof(*mld2q))) {
+                        err = -EINVAL;
+                        goto out;
+                }
+                mld2q = (struct mld2_query *)icmp6_hdr(skb);
+                if (!mld2q->mld2q_nsrcs)
+                        group = &mld2q->mld2q_mca;
+                max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
+        }
+
+        if (!group)
+                goto out;
+
+        mp = br_mdb_ip6_get(br->mdb, group);
+        if (!mp)
+                goto out;
+
+        max_delay *= br->multicast_last_member_count;
+        if (!hlist_unhashed(&mp->mglist) &&
+            (timer_pending(&mp->timer) ?
+             time_after(mp->timer.expires, now + max_delay) :
+             try_to_del_timer_sync(&mp->timer) >= 0))
+                mod_timer(&mp->timer, now + max_delay);
+
+        for (pp = &mp->ports; (p = *pp); pp = &p->next) {
+                if (timer_pending(&p->timer) ?
+                    time_after(p->timer.expires, now + max_delay) :
+                    try_to_del_timer_sync(&p->timer) >= 0)
+                        mod_timer(&mp->timer, now + max_delay);
+        }
+
+out:
+        spin_unlock(&br->multicast_lock);
+        return err;
+}
+#endif
+
 static void br_multicast_leave_group(struct net_bridge *br,
                                      struct net_bridge_port *port,
                                      struct br_ip *group)
@@ -1030,6 +1312,22 @@ static void br_ip4_multicast_leave_group(struct net_bridge *br,
         br_multicast_leave_group(br, port, &br_group);
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static void br_ip6_multicast_leave_group(struct net_bridge *br,
+                                         struct net_bridge_port *port,
+                                         const struct in6_addr *group)
+{
+        struct br_ip br_group;
+
+        if (ipv6_is_local_multicast(group))
+                return;
+
+        ipv6_addr_copy(&br_group.u.ip6, group);
+        br_group.proto = htons(ETH_P_IPV6);
+
+        br_multicast_leave_group(br, port, &br_group);
+}
+#endif
 
 static int br_multicast_ipv4_rcv(struct net_bridge *br,
                                  struct net_bridge_port *port,
@@ -1129,6 +1427,126 @@ err_out:
         return err;
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static int br_multicast_ipv6_rcv(struct net_bridge *br,
+                                 struct net_bridge_port *port,
+                                 struct sk_buff *skb)
+{
+        struct sk_buff *skb2 = skb;
+        struct ipv6hdr *ip6h;
+        struct icmp6hdr *icmp6h;
+        u8 nexthdr;
+        unsigned len;
+        unsigned offset;
+        int err;
+
+        BR_INPUT_SKB_CB(skb)->igmp = 0;
+        BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
+
+        if (!pskb_may_pull(skb, sizeof(*ip6h)))
+                return -EINVAL;
+
+        ip6h = ipv6_hdr(skb);
+
+        /*
+         * We're interested in MLD messages only.
+         *  - Version is 6
+         *  - MLD has always Router Alert hop-by-hop option
+         *  - But we do not support jumbrograms.
+         */
+        if (ip6h->version != 6 ||
+            ip6h->nexthdr != IPPROTO_HOPOPTS ||
+            ip6h->payload_len == 0)
+                return 0;
+
+        len = ntohs(ip6h->payload_len);
+        if (skb->len < len)
+                return -EINVAL;
+
+        nexthdr = ip6h->nexthdr;
+        offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr);
+
+        if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
+                return 0;
+
+        /* Okay, we found ICMPv6 header */
+        skb2 = skb_clone(skb, GFP_ATOMIC);
+        if (!skb2)
+                return -ENOMEM;
+
+        len -= offset - skb_network_offset(skb2);
+
+        __skb_pull(skb2, offset);
+        skb_reset_transport_header(skb2);
+
+        err = -EINVAL;
+        if (!pskb_may_pull(skb2, sizeof(*icmp6h)))
+                goto out;
+
+        icmp6h = icmp6_hdr(skb2);
+
+        switch (icmp6h->icmp6_type) {
+        case ICMPV6_MGM_QUERY:
+        case ICMPV6_MGM_REPORT:
+        case ICMPV6_MGM_REDUCTION:
+        case ICMPV6_MLD2_REPORT:
+                break;
+        default:
+                err = 0;
+                goto out;
+        }
+
+        /* Okay, we found MLD message. Check further. */
+        if (skb2->len > len) {
+                err = pskb_trim_rcsum(skb2, len);
+                if (err)
+                        goto out;
+        }
+
+        switch (skb2->ip_summed) {
+        case CHECKSUM_COMPLETE:
+                if (!csum_fold(skb2->csum))
+                        break;
+                /*FALLTHROUGH*/
+        case CHECKSUM_NONE:
+                skb2->csum = 0;
+                if (skb_checksum_complete(skb2))
+                        goto out;
+        }
+
+        err = 0;
+
+        BR_INPUT_SKB_CB(skb)->igmp = 1;
+
+        switch (icmp6h->icmp6_type) {
+        case ICMPV6_MGM_REPORT:
+            {
+                struct mld_msg *mld = (struct mld_msg *)icmp6h;
+                BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
+                err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
+                break;
+            }
+        case ICMPV6_MLD2_REPORT:
+                err = br_ip6_multicast_mld2_report(br, port, skb2);
+                break;
+        case ICMPV6_MGM_QUERY:
+                err = br_ip6_multicast_query(br, port, skb2);
+                break;
+        case ICMPV6_MGM_REDUCTION:
+            {
+                struct mld_msg *mld = (struct mld_msg *)icmp6h;
+                br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
+            }
+        }
+
+out:
+        __skb_push(skb2, offset);
+        if (skb2 != skb)
+                kfree_skb(skb2);
+        return err;
+}
+#endif
+
 int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
                      struct sk_buff *skb)
 {
@@ -1138,6 +1556,10 @@ int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
         switch (skb->protocol) {
         case htons(ETH_P_IP):
                 return br_multicast_ipv4_rcv(br, port, skb);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case htons(ETH_P_IPV6):
+                return br_multicast_ipv6_rcv(br, port, skb);
+#endif
         }
 
         return 0;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 45d11e49fbbb..018499ebe19d 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -49,6 +49,9 @@ struct br_ip
 {
         union {
                 __be32  ip4;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+                struct in6_addr ip6;
+#endif
         } u;
         __be16          proto;
 };