Merge branch 'igmp_mld_export'
Linus Lüssing says: ==================== Exporting IGMP/MLD checking from bridge code The multicast optimizations in batman-adv are yet only usable and enabled in non-bridged scenarios. To be able to support bridged setups batman-adv needs to be able to detect IGMP/MLD queriers and reports on mesh nodes without bridges, too. See the following link for details: http://www.open-mesh.org/projects/batman-adv/wiki/Multicast-optimizations-listener-reports To avoid duplicate code between the bridge and batman-adv, the IGMP/MLD message validation code is moved from the bridge to the IPv4/IPv6 stack. On the way, some refactoring to increase readability and to iron out some subtle differences between the IGMP and MLD parsing code is done. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
commit
29a1ff6596
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@ -130,5 +130,6 @@ extern void ip_mc_unmap(struct in_device *);
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extern void ip_mc_remap(struct in_device *);
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extern void ip_mc_dec_group(struct in_device *in_dev, __be32 addr);
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extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
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int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed);
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#endif
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@ -3419,6 +3419,9 @@ static inline void skb_checksum_none_assert(const struct sk_buff *skb)
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bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
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int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
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struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
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unsigned int transport_len,
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__sum16(*skb_chkf)(struct sk_buff *skb));
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u32 skb_get_poff(const struct sk_buff *skb);
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u32 __skb_get_poff(const struct sk_buff *skb, void *data,
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@ -142,6 +142,7 @@ void ipv6_mc_unmap(struct inet6_dev *idev);
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void ipv6_mc_remap(struct inet6_dev *idev);
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void ipv6_mc_init_dev(struct inet6_dev *idev);
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void ipv6_mc_destroy_dev(struct inet6_dev *idev);
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int ipv6_mc_check_mld(struct sk_buff *skb, struct sk_buff **skb_trimmed);
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void addrconf_dad_failure(struct inet6_ifaddr *ifp);
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bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
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@ -975,9 +975,6 @@ static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
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int err = 0;
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__be32 group;
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if (!pskb_may_pull(skb, sizeof(*ih)))
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return -EINVAL;
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ih = igmpv3_report_hdr(skb);
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num = ntohs(ih->ngrec);
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len = sizeof(*ih);
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@ -1248,25 +1245,14 @@ static int br_ip4_multicast_query(struct net_bridge *br,
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max_delay = 10 * HZ;
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group = 0;
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}
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} else {
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if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
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err = -EINVAL;
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goto out;
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}
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} else if (skb->len >= sizeof(*ih3)) {
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ih3 = igmpv3_query_hdr(skb);
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if (ih3->nsrcs)
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goto out;
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max_delay = ih3->code ?
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IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
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}
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/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
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* all-systems destination addresses (224.0.0.1) for general queries
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*/
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if (!group && iph->daddr != htonl(INADDR_ALLHOSTS_GROUP)) {
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err = -EINVAL;
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} else {
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goto out;
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}
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@ -1329,12 +1315,6 @@ static int br_ip6_multicast_query(struct net_bridge *br,
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(port && port->state == BR_STATE_DISABLED))
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goto out;
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/* RFC2710+RFC3810 (MLDv1+MLDv2) require link-local source addresses */
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if (!(ipv6_addr_type(&ip6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
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err = -EINVAL;
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goto out;
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}
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if (skb->len == sizeof(*mld)) {
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if (!pskb_may_pull(skb, sizeof(*mld))) {
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err = -EINVAL;
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@ -1358,14 +1338,6 @@ static int br_ip6_multicast_query(struct net_bridge *br,
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is_general_query = group && ipv6_addr_any(group);
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/* RFC2710+RFC3810 (MLDv1+MLDv2) require the multicast link layer
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* all-nodes destination address (ff02::1) for general queries
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*/
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if (is_general_query && !ipv6_addr_is_ll_all_nodes(&ip6h->daddr)) {
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err = -EINVAL;
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goto out;
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}
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if (is_general_query) {
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saddr.proto = htons(ETH_P_IPV6);
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saddr.u.ip6 = ip6h->saddr;
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@ -1557,74 +1529,22 @@ static int br_multicast_ipv4_rcv(struct net_bridge *br,
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struct sk_buff *skb,
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u16 vid)
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{
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struct sk_buff *skb2 = skb;
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const struct iphdr *iph;
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struct sk_buff *skb_trimmed = NULL;
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struct igmphdr *ih;
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unsigned int len;
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unsigned int offset;
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int err;
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/* We treat OOM as packet loss for now. */
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if (!pskb_may_pull(skb, sizeof(*iph)))
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return -EINVAL;
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err = ip_mc_check_igmp(skb, &skb_trimmed);
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iph = ip_hdr(skb);
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if (iph->ihl < 5 || iph->version != 4)
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return -EINVAL;
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if (!pskb_may_pull(skb, ip_hdrlen(skb)))
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return -EINVAL;
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iph = ip_hdr(skb);
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if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
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return -EINVAL;
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if (iph->protocol != IPPROTO_IGMP) {
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if (!ipv4_is_local_multicast(iph->daddr))
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if (err == -ENOMSG) {
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if (!ipv4_is_local_multicast(ip_hdr(skb)->daddr))
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BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
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return 0;
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} else if (err < 0) {
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return err;
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}
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len = ntohs(iph->tot_len);
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if (skb->len < len || len < ip_hdrlen(skb))
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return -EINVAL;
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if (skb->len > len) {
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skb2 = skb_clone(skb, GFP_ATOMIC);
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if (!skb2)
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return -ENOMEM;
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err = pskb_trim_rcsum(skb2, len);
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if (err)
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goto err_out;
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}
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len -= ip_hdrlen(skb2);
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offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
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__skb_pull(skb2, offset);
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skb_reset_transport_header(skb2);
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err = -EINVAL;
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if (!pskb_may_pull(skb2, sizeof(*ih)))
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goto out;
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switch (skb2->ip_summed) {
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case CHECKSUM_COMPLETE:
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if (!csum_fold(skb2->csum))
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break;
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/* fall through */
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case CHECKSUM_NONE:
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skb2->csum = 0;
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if (skb_checksum_complete(skb2))
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goto out;
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}
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err = 0;
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BR_INPUT_SKB_CB(skb)->igmp = 1;
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ih = igmp_hdr(skb2);
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ih = igmp_hdr(skb);
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switch (ih->type) {
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case IGMP_HOST_MEMBERSHIP_REPORT:
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@ -1633,21 +1553,19 @@ static int br_multicast_ipv4_rcv(struct net_bridge *br,
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err = br_ip4_multicast_add_group(br, port, ih->group, vid);
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break;
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case IGMPV3_HOST_MEMBERSHIP_REPORT:
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err = br_ip4_multicast_igmp3_report(br, port, skb2, vid);
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err = br_ip4_multicast_igmp3_report(br, port, skb_trimmed, vid);
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break;
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case IGMP_HOST_MEMBERSHIP_QUERY:
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err = br_ip4_multicast_query(br, port, skb2, vid);
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err = br_ip4_multicast_query(br, port, skb_trimmed, vid);
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break;
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case IGMP_HOST_LEAVE_MESSAGE:
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br_ip4_multicast_leave_group(br, port, ih->group, vid);
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break;
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}
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out:
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__skb_push(skb2, offset);
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err_out:
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if (skb2 != skb)
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kfree_skb(skb2);
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if (skb_trimmed)
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kfree_skb(skb_trimmed);
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return err;
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}
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@ -1657,138 +1575,42 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br,
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struct sk_buff *skb,
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u16 vid)
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{
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struct sk_buff *skb2;
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const struct ipv6hdr *ip6h;
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u8 icmp6_type;
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u8 nexthdr;
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__be16 frag_off;
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unsigned int len;
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int offset;
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struct sk_buff *skb_trimmed = NULL;
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struct mld_msg *mld;
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int err;
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if (!pskb_may_pull(skb, sizeof(*ip6h)))
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return -EINVAL;
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err = ipv6_mc_check_mld(skb, &skb_trimmed);
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ip6h = ipv6_hdr(skb);
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/*
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* We're interested in MLD messages only.
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* - Version is 6
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* - MLD has always Router Alert hop-by-hop option
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* - But we do not support jumbrograms.
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*/
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if (ip6h->version != 6)
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if (err == -ENOMSG) {
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if (!ipv6_addr_is_ll_all_nodes(&ipv6_hdr(skb)->daddr))
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BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
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return 0;
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/* Prevent flooding this packet if there is no listener present */
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if (!ipv6_addr_is_ll_all_nodes(&ip6h->daddr))
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BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
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if (ip6h->nexthdr != IPPROTO_HOPOPTS ||
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ip6h->payload_len == 0)
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return 0;
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len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
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if (skb->len < len)
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return -EINVAL;
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nexthdr = ip6h->nexthdr;
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offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
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if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
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return 0;
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/* Okay, we found ICMPv6 header */
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skb2 = skb_clone(skb, GFP_ATOMIC);
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if (!skb2)
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return -ENOMEM;
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err = -EINVAL;
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if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
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goto out;
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len -= offset - skb_network_offset(skb2);
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__skb_pull(skb2, offset);
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skb_reset_transport_header(skb2);
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skb_postpull_rcsum(skb2, skb_network_header(skb2),
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skb_network_header_len(skb2));
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icmp6_type = icmp6_hdr(skb2)->icmp6_type;
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switch (icmp6_type) {
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case ICMPV6_MGM_QUERY:
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case ICMPV6_MGM_REPORT:
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case ICMPV6_MGM_REDUCTION:
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case ICMPV6_MLD2_REPORT:
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break;
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default:
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err = 0;
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goto out;
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} else if (err < 0) {
|
||||
return err;
|
||||
}
|
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|
||||
/* Okay, we found MLD message. Check further. */
|
||||
if (skb2->len > len) {
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||||
err = pskb_trim_rcsum(skb2, len);
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||||
if (err)
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||||
goto out;
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||||
err = -EINVAL;
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||||
}
|
||||
|
||||
ip6h = ipv6_hdr(skb2);
|
||||
|
||||
switch (skb2->ip_summed) {
|
||||
case CHECKSUM_COMPLETE:
|
||||
if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
|
||||
IPPROTO_ICMPV6, skb2->csum))
|
||||
break;
|
||||
/*FALLTHROUGH*/
|
||||
case CHECKSUM_NONE:
|
||||
skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
|
||||
&ip6h->daddr,
|
||||
skb2->len,
|
||||
IPPROTO_ICMPV6, 0));
|
||||
if (__skb_checksum_complete(skb2))
|
||||
goto out;
|
||||
}
|
||||
|
||||
err = 0;
|
||||
|
||||
BR_INPUT_SKB_CB(skb)->igmp = 1;
|
||||
mld = (struct mld_msg *)skb_transport_header(skb);
|
||||
|
||||
switch (icmp6_type) {
|
||||
switch (mld->mld_type) {
|
||||
case ICMPV6_MGM_REPORT:
|
||||
{
|
||||
struct mld_msg *mld;
|
||||
if (!pskb_may_pull(skb2, sizeof(*mld))) {
|
||||
err = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
mld = (struct mld_msg *)skb_transport_header(skb2);
|
||||
BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
|
||||
err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid);
|
||||
break;
|
||||
}
|
||||
case ICMPV6_MLD2_REPORT:
|
||||
err = br_ip6_multicast_mld2_report(br, port, skb2, vid);
|
||||
err = br_ip6_multicast_mld2_report(br, port, skb_trimmed, vid);
|
||||
break;
|
||||
case ICMPV6_MGM_QUERY:
|
||||
err = br_ip6_multicast_query(br, port, skb2, vid);
|
||||
err = br_ip6_multicast_query(br, port, skb_trimmed, vid);
|
||||
break;
|
||||
case ICMPV6_MGM_REDUCTION:
|
||||
{
|
||||
struct mld_msg *mld;
|
||||
if (!pskb_may_pull(skb2, sizeof(*mld))) {
|
||||
err = -EINVAL;
|
||||
goto out;
|
||||
}
|
||||
mld = (struct mld_msg *)skb_transport_header(skb2);
|
||||
br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid);
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
out:
|
||||
kfree_skb(skb2);
|
||||
if (skb_trimmed)
|
||||
kfree_skb(skb_trimmed);
|
||||
|
||||
return err;
|
||||
}
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -4030,6 +4030,93 @@ int skb_checksum_setup(struct sk_buff *skb, bool recalculate)
|
|||
}
|
||||
EXPORT_SYMBOL(skb_checksum_setup);
|
||||
|
||||
/**
|
||||
* skb_checksum_maybe_trim - maybe trims the given skb
|
||||
* @skb: the skb to check
|
||||
* @transport_len: the data length beyond the network header
|
||||
*
|
||||
* Checks whether the given skb has data beyond the given transport length.
|
||||
* If so, returns a cloned skb trimmed to this transport length.
|
||||
* Otherwise returns the provided skb. Returns NULL in error cases
|
||||
* (e.g. transport_len exceeds skb length or out-of-memory).
|
||||
*
|
||||
* Caller needs to set the skb transport header and release the returned skb.
|
||||
* Provided skb is consumed.
|
||||
*/
|
||||
static struct sk_buff *skb_checksum_maybe_trim(struct sk_buff *skb,
|
||||
unsigned int transport_len)
|
||||
{
|
||||
struct sk_buff *skb_chk;
|
||||
unsigned int len = skb_transport_offset(skb) + transport_len;
|
||||
int ret;
|
||||
|
||||
if (skb->len < len) {
|
||||
kfree_skb(skb);
|
||||
return NULL;
|
||||
} else if (skb->len == len) {
|
||||
return skb;
|
||||
}
|
||||
|
||||
skb_chk = skb_clone(skb, GFP_ATOMIC);
|
||||
kfree_skb(skb);
|
||||
|
||||
if (!skb_chk)
|
||||
return NULL;
|
||||
|
||||
ret = pskb_trim_rcsum(skb_chk, len);
|
||||
if (ret) {
|
||||
kfree_skb(skb_chk);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
return skb_chk;
|
||||
}
|
||||
|
||||
/**
|
||||
* skb_checksum_trimmed - validate checksum of an skb
|
||||
* @skb: the skb to check
|
||||
* @transport_len: the data length beyond the network header
|
||||
* @skb_chkf: checksum function to use
|
||||
*
|
||||
* Applies the given checksum function skb_chkf to the provided skb.
|
||||
* Returns a checked and maybe trimmed skb. Returns NULL on error.
|
||||
*
|
||||
* If the skb has data beyond the given transport length, then a
|
||||
* trimmed & cloned skb is checked and returned.
|
||||
*
|
||||
* Caller needs to set the skb transport header and release the returned skb.
|
||||
* Provided skb is consumed.
|
||||
*/
|
||||
struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
|
||||
unsigned int transport_len,
|
||||
__sum16(*skb_chkf)(struct sk_buff *skb))
|
||||
{
|
||||
struct sk_buff *skb_chk;
|
||||
unsigned int offset = skb_transport_offset(skb);
|
||||
int ret;
|
||||
|
||||
skb_chk = skb_checksum_maybe_trim(skb, transport_len);
|
||||
if (!skb_chk)
|
||||
return NULL;
|
||||
|
||||
if (!pskb_may_pull(skb_chk, offset)) {
|
||||
kfree_skb(skb_chk);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
__skb_pull(skb_chk, offset);
|
||||
ret = skb_chkf(skb_chk);
|
||||
__skb_push(skb_chk, offset);
|
||||
|
||||
if (ret) {
|
||||
kfree_skb(skb_chk);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
return skb_chk;
|
||||
}
|
||||
EXPORT_SYMBOL(skb_checksum_trimmed);
|
||||
|
||||
void __skb_warn_lro_forwarding(const struct sk_buff *skb)
|
||||
{
|
||||
net_warn_ratelimited("%s: received packets cannot be forwarded while LRO is enabled\n",
|
||||
|
|
|
|||
162
net/ipv4/igmp.c
162
net/ipv4/igmp.c
|
|
@ -1339,6 +1339,168 @@ out:
|
|||
}
|
||||
EXPORT_SYMBOL(ip_mc_inc_group);
|
||||
|
||||
static int ip_mc_check_iphdr(struct sk_buff *skb)
|
||||
{
|
||||
const struct iphdr *iph;
|
||||
unsigned int len;
|
||||
unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
|
||||
|
||||
if (!pskb_may_pull(skb, offset))
|
||||
return -EINVAL;
|
||||
|
||||
iph = ip_hdr(skb);
|
||||
|
||||
if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
|
||||
return -EINVAL;
|
||||
|
||||
offset += ip_hdrlen(skb) - sizeof(*iph);
|
||||
|
||||
if (!pskb_may_pull(skb, offset))
|
||||
return -EINVAL;
|
||||
|
||||
iph = ip_hdr(skb);
|
||||
|
||||
if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
|
||||
return -EINVAL;
|
||||
|
||||
len = skb_network_offset(skb) + ntohs(iph->tot_len);
|
||||
if (skb->len < len || len < offset)
|
||||
return -EINVAL;
|
||||
|
||||
skb_set_transport_header(skb, offset);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
|
||||
{
|
||||
unsigned int len = skb_transport_offset(skb);
|
||||
|
||||
len += sizeof(struct igmpv3_report);
|
||||
|
||||
return pskb_may_pull(skb, len) ? 0 : -EINVAL;
|
||||
}
|
||||
|
||||
static int ip_mc_check_igmp_query(struct sk_buff *skb)
|
||||
{
|
||||
unsigned int len = skb_transport_offset(skb);
|
||||
|
||||
len += sizeof(struct igmphdr);
|
||||
if (skb->len < len)
|
||||
return -EINVAL;
|
||||
|
||||
/* IGMPv{1,2}? */
|
||||
if (skb->len != len) {
|
||||
/* or IGMPv3? */
|
||||
len += sizeof(struct igmpv3_query) - sizeof(struct igmphdr);
|
||||
if (skb->len < len || !pskb_may_pull(skb, len))
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
|
||||
* all-systems destination addresses (224.0.0.1) for general queries
|
||||
*/
|
||||
if (!igmp_hdr(skb)->group &&
|
||||
ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
|
||||
return -EINVAL;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ip_mc_check_igmp_msg(struct sk_buff *skb)
|
||||
{
|
||||
switch (igmp_hdr(skb)->type) {
|
||||
case IGMP_HOST_LEAVE_MESSAGE:
|
||||
case IGMP_HOST_MEMBERSHIP_REPORT:
|
||||
case IGMPV2_HOST_MEMBERSHIP_REPORT:
|
||||
/* fall through */
|
||||
return 0;
|
||||
case IGMPV3_HOST_MEMBERSHIP_REPORT:
|
||||
return ip_mc_check_igmp_reportv3(skb);
|
||||
case IGMP_HOST_MEMBERSHIP_QUERY:
|
||||
return ip_mc_check_igmp_query(skb);
|
||||
default:
|
||||
return -ENOMSG;
|
||||
}
|
||||
}
|
||||
|
||||
static inline __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
|
||||
{
|
||||
return skb_checksum_simple_validate(skb);
|
||||
}
|
||||
|
||||
static int __ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
|
||||
|
||||
{
|
||||
struct sk_buff *skb_chk;
|
||||
unsigned int transport_len;
|
||||
unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
|
||||
int ret;
|
||||
|
||||
transport_len = ntohs(ip_hdr(skb)->tot_len) - ip_hdrlen(skb);
|
||||
|
||||
skb_get(skb);
|
||||
skb_chk = skb_checksum_trimmed(skb, transport_len,
|
||||
ip_mc_validate_checksum);
|
||||
if (!skb_chk)
|
||||
return -EINVAL;
|
||||
|
||||
if (!pskb_may_pull(skb_chk, len)) {
|
||||
kfree_skb(skb_chk);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
ret = ip_mc_check_igmp_msg(skb_chk);
|
||||
if (ret) {
|
||||
kfree_skb(skb_chk);
|
||||
return ret;
|
||||
}
|
||||
|
||||
if (skb_trimmed)
|
||||
*skb_trimmed = skb_chk;
|
||||
else
|
||||
kfree_skb(skb_chk);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* ip_mc_check_igmp - checks whether this is a sane IGMP packet
|
||||
* @skb: the skb to validate
|
||||
* @skb_trimmed: to store an skb pointer trimmed to IPv4 packet tail (optional)
|
||||
*
|
||||
* Checks whether an IPv4 packet is a valid IGMP packet. If so sets
|
||||
* skb network and transport headers accordingly and returns zero.
|
||||
*
|
||||
* -EINVAL: A broken packet was detected, i.e. it violates some internet
|
||||
* standard
|
||||
* -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
|
||||
* -ENOMEM: A memory allocation failure happened.
|
||||
*
|
||||
* Optionally, an skb pointer might be provided via skb_trimmed (or set it
|
||||
* to NULL): After parsing an IGMP packet successfully it will point to
|
||||
* an skb which has its tail aligned to the IP packet end. This might
|
||||
* either be the originally provided skb or a trimmed, cloned version if
|
||||
* the skb frame had data beyond the IP packet. A cloned skb allows us
|
||||
* to leave the original skb and its full frame unchanged (which might be
|
||||
* desirable for layer 2 frame jugglers).
|
||||
*
|
||||
* The caller needs to release a reference count from any returned skb_trimmed.
|
||||
*/
|
||||
int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
|
||||
{
|
||||
int ret = ip_mc_check_iphdr(skb);
|
||||
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
|
||||
return -ENOMSG;
|
||||
|
||||
return __ip_mc_check_igmp(skb, skb_trimmed);
|
||||
}
|
||||
EXPORT_SYMBOL(ip_mc_check_igmp);
|
||||
|
||||
/*
|
||||
* Resend IGMP JOIN report; used by netdev notifier.
|
||||
*/
|
||||
|
|
|
|||
|
|
@ -48,4 +48,5 @@ obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o
|
|||
|
||||
ifneq ($(CONFIG_IPV6),)
|
||||
obj-$(CONFIG_NET_UDP_TUNNEL) += ip6_udp_tunnel.o
|
||||
obj-y += mcast_snoop.o
|
||||
endif
|
||||
|
|
|
|||
213
net/ipv6/mcast_snoop.c
Normal file
213
net/ipv6/mcast_snoop.c
Normal file
|
|
@ -0,0 +1,213 @@
|
|||
/* Copyright (C) 2010: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
|
||||
* Copyright (C) 2015: Linus Lüssing <linus.luessing@c0d3.blue>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of version 2 of the GNU General Public
|
||||
* License as published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful, but
|
||||
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
*
|
||||
* Based on the MLD support added to br_multicast.c by YOSHIFUJI Hideaki.
|
||||
*/
|
||||
|
||||
#include <linux/skbuff.h>
|
||||
#include <net/ipv6.h>
|
||||
#include <net/mld.h>
|
||||
#include <net/addrconf.h>
|
||||
#include <net/ip6_checksum.h>
|
||||
|
||||
static int ipv6_mc_check_ip6hdr(struct sk_buff *skb)
|
||||
{
|
||||
const struct ipv6hdr *ip6h;
|
||||
unsigned int len;
|
||||
unsigned int offset = skb_network_offset(skb) + sizeof(*ip6h);
|
||||
|
||||
if (!pskb_may_pull(skb, offset))
|
||||
return -EINVAL;
|
||||
|
||||
ip6h = ipv6_hdr(skb);
|
||||
|
||||
if (ip6h->version != 6)
|
||||
return -EINVAL;
|
||||
|
||||
len = offset + ntohs(ip6h->payload_len);
|
||||
if (skb->len < len || len <= offset)
|
||||
return -EINVAL;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ipv6_mc_check_exthdrs(struct sk_buff *skb)
|
||||
{
|
||||
const struct ipv6hdr *ip6h;
|
||||
unsigned int offset;
|
||||
u8 nexthdr;
|
||||
__be16 frag_off;
|
||||
|
||||
ip6h = ipv6_hdr(skb);
|
||||
|
||||
if (ip6h->nexthdr != IPPROTO_HOPOPTS)
|
||||
return -ENOMSG;
|
||||
|
||||
nexthdr = ip6h->nexthdr;
|
||||
offset = skb_network_offset(skb) + sizeof(*ip6h);
|
||||
offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
|
||||
|
||||
if (offset < 0)
|
||||
return -EINVAL;
|
||||
|
||||
if (nexthdr != IPPROTO_ICMPV6)
|
||||
return -ENOMSG;
|
||||
|
||||
skb_set_transport_header(skb, offset);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ipv6_mc_check_mld_reportv2(struct sk_buff *skb)
|
||||
{
|
||||
unsigned int len = skb_transport_offset(skb);
|
||||
|
||||
len += sizeof(struct mld2_report);
|
||||
|
||||
return pskb_may_pull(skb, len) ? 0 : -EINVAL;
|
||||
}
|
||||
|
||||
static int ipv6_mc_check_mld_query(struct sk_buff *skb)
|
||||
{
|
||||
struct mld_msg *mld;
|
||||
unsigned int len = skb_transport_offset(skb);
|
||||
|
||||
/* RFC2710+RFC3810 (MLDv1+MLDv2) require link-local source addresses */
|
||||
if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL))
|
||||
return -EINVAL;
|
||||
|
||||
len += sizeof(struct mld_msg);
|
||||
if (skb->len < len)
|
||||
return -EINVAL;
|
||||
|
||||
/* MLDv1? */
|
||||
if (skb->len != len) {
|
||||
/* or MLDv2? */
|
||||
len += sizeof(struct mld2_query) - sizeof(struct mld_msg);
|
||||
if (skb->len < len || !pskb_may_pull(skb, len))
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
mld = (struct mld_msg *)skb_transport_header(skb);
|
||||
|
||||
/* RFC2710+RFC3810 (MLDv1+MLDv2) require the multicast link layer
|
||||
* all-nodes destination address (ff02::1) for general queries
|
||||
*/
|
||||
if (ipv6_addr_any(&mld->mld_mca) &&
|
||||
!ipv6_addr_is_ll_all_nodes(&ipv6_hdr(skb)->daddr))
|
||||
return -EINVAL;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ipv6_mc_check_mld_msg(struct sk_buff *skb)
|
||||
{
|
||||
struct mld_msg *mld = (struct mld_msg *)skb_transport_header(skb);
|
||||
|
||||
switch (mld->mld_type) {
|
||||
case ICMPV6_MGM_REDUCTION:
|
||||
case ICMPV6_MGM_REPORT:
|
||||
/* fall through */
|
||||
return 0;
|
||||
case ICMPV6_MLD2_REPORT:
|
||||
return ipv6_mc_check_mld_reportv2(skb);
|
||||
case ICMPV6_MGM_QUERY:
|
||||
return ipv6_mc_check_mld_query(skb);
|
||||
default:
|
||||
return -ENOMSG;
|
||||
}
|
||||
}
|
||||
|
||||
static inline __sum16 ipv6_mc_validate_checksum(struct sk_buff *skb)
|
||||
{
|
||||
return skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo);
|
||||
}
|
||||
|
||||
static int __ipv6_mc_check_mld(struct sk_buff *skb,
|
||||
struct sk_buff **skb_trimmed)
|
||||
|
||||
{
|
||||
struct sk_buff *skb_chk = NULL;
|
||||
unsigned int transport_len;
|
||||
unsigned int len = skb_transport_offset(skb) + sizeof(struct mld_msg);
|
||||
int ret;
|
||||
|
||||
transport_len = ntohs(ipv6_hdr(skb)->payload_len);
|
||||
transport_len -= skb_transport_offset(skb) - sizeof(struct ipv6hdr);
|
||||
|
||||
skb_get(skb);
|
||||
skb_chk = skb_checksum_trimmed(skb, transport_len,
|
||||
ipv6_mc_validate_checksum);
|
||||
if (!skb_chk)
|
||||
return -EINVAL;
|
||||
|
||||
if (!pskb_may_pull(skb_chk, len)) {
|
||||
kfree_skb(skb_chk);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
ret = ipv6_mc_check_mld_msg(skb_chk);
|
||||
if (ret) {
|
||||
kfree_skb(skb_chk);
|
||||
return ret;
|
||||
}
|
||||
|
||||
if (skb_trimmed)
|
||||
*skb_trimmed = skb_chk;
|
||||
else
|
||||
kfree_skb(skb_chk);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* ipv6_mc_check_mld - checks whether this is a sane MLD packet
|
||||
* @skb: the skb to validate
|
||||
* @skb_trimmed: to store an skb pointer trimmed to IPv6 packet tail (optional)
|
||||
*
|
||||
* Checks whether an IPv6 packet is a valid MLD packet. If so sets
|
||||
* skb network and transport headers accordingly and returns zero.
|
||||
*
|
||||
* -EINVAL: A broken packet was detected, i.e. it violates some internet
|
||||
* standard
|
||||
* -ENOMSG: IP header validation succeeded but it is not an MLD packet.
|
||||
* -ENOMEM: A memory allocation failure happened.
|
||||
*
|
||||
* Optionally, an skb pointer might be provided via skb_trimmed (or set it
|
||||
* to NULL): After parsing an MLD packet successfully it will point to
|
||||
* an skb which has its tail aligned to the IP packet end. This might
|
||||
* either be the originally provided skb or a trimmed, cloned version if
|
||||
* the skb frame had data beyond the IP packet. A cloned skb allows us
|
||||
* to leave the original skb and its full frame unchanged (which might be
|
||||
* desirable for layer 2 frame jugglers).
|
||||
*
|
||||
* The caller needs to release a reference count from any returned skb_trimmed.
|
||||
*/
|
||||
int ipv6_mc_check_mld(struct sk_buff *skb, struct sk_buff **skb_trimmed)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = ipv6_mc_check_ip6hdr(skb);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
ret = ipv6_mc_check_exthdrs(skb);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return __ipv6_mc_check_mld(skb, skb_trimmed);
|
||||
}
|
||||
EXPORT_SYMBOL(ipv6_mc_check_mld);
|
||||
Loading…
Reference in a new issue