diff options
Diffstat (limited to 'kernel/net/ipv4/igmp.c')
| -rw-r--r-- | kernel/net/ipv4/igmp.c | 214 |
1 files changed, 200 insertions, 14 deletions
diff --git a/kernel/net/ipv4/igmp.c b/kernel/net/ipv4/igmp.c index a3a697f5f..05e4cba14 100644 --- a/kernel/net/ipv4/igmp.c +++ b/kernel/net/ipv4/igmp.c @@ -110,6 +110,9 @@ #define IP_MAX_MEMBERSHIPS 20 #define IP_MAX_MSF 10 +/* IGMP reports for link-local multicast groups are enabled by default */ +int sysctl_igmp_llm_reports __read_mostly = 1; + #ifdef CONFIG_IP_MULTICAST /* Parameter names and values are taken from igmp-v2-06 draft */ @@ -394,7 +397,7 @@ static int igmpv3_sendpack(struct sk_buff *skb) pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen); - return ip_local_out(skb); + return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); } static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel) @@ -437,6 +440,8 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, if (pmc->multiaddr == IGMP_ALL_HOSTS) return skb; + if (ipv4_is_local_multicast(pmc->multiaddr) && !sysctl_igmp_llm_reports) + return skb; isquery = type == IGMPV3_MODE_IS_INCLUDE || type == IGMPV3_MODE_IS_EXCLUDE; @@ -545,6 +550,9 @@ static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc) for_each_pmc_rcu(in_dev, pmc) { if (pmc->multiaddr == IGMP_ALL_HOSTS) continue; + if (ipv4_is_local_multicast(pmc->multiaddr) && + !sysctl_igmp_llm_reports) + continue; spin_lock_bh(&pmc->lock); if (pmc->sfcount[MCAST_EXCLUDE]) type = IGMPV3_MODE_IS_EXCLUDE; @@ -678,7 +686,11 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc, if (type == IGMPV3_HOST_MEMBERSHIP_REPORT) return igmpv3_send_report(in_dev, pmc); - else if (type == IGMP_HOST_LEAVE_MESSAGE) + + if (ipv4_is_local_multicast(group) && !sysctl_igmp_llm_reports) + return 0; + + if (type == IGMP_HOST_LEAVE_MESSAGE) dst = IGMP_ALL_ROUTER; else dst = group; @@ -727,7 +739,7 @@ static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc, ih->group = group; ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr)); - return ip_local_out(skb); + return ip_local_out(net, skb->sk, skb); } static void igmp_gq_timer_expire(unsigned long data) @@ -851,6 +863,8 @@ static bool igmp_heard_report(struct in_device *in_dev, __be32 group) if (group == IGMP_ALL_HOSTS) return false; + if (ipv4_is_local_multicast(group) && !sysctl_igmp_llm_reports) + return false; rcu_read_lock(); for_each_pmc_rcu(in_dev, im) { @@ -957,6 +971,9 @@ static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb, continue; if (im->multiaddr == IGMP_ALL_HOSTS) continue; + if (ipv4_is_local_multicast(im->multiaddr) && + !sysctl_igmp_llm_reports) + continue; spin_lock_bh(&im->lock); if (im->tm_running) im->gsquery = im->gsquery && mark; @@ -1181,6 +1198,8 @@ static void igmp_group_dropped(struct ip_mc_list *im) #ifdef CONFIG_IP_MULTICAST if (im->multiaddr == IGMP_ALL_HOSTS) return; + if (ipv4_is_local_multicast(im->multiaddr) && !sysctl_igmp_llm_reports) + return; reporter = im->reporter; igmp_stop_timer(im); @@ -1213,6 +1232,8 @@ static void igmp_group_added(struct ip_mc_list *im) #ifdef CONFIG_IP_MULTICAST if (im->multiaddr == IGMP_ALL_HOSTS) return; + if (ipv4_is_local_multicast(im->multiaddr) && !sysctl_igmp_llm_reports) + return; if (in_dev->dead) return; @@ -1339,6 +1360,171 @@ 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 = -EINVAL; + + transport_len = ntohs(ip_hdr(skb)->tot_len) - ip_hdrlen(skb); + + skb_chk = skb_checksum_trimmed(skb, transport_len, + ip_mc_validate_checksum); + if (!skb_chk) + goto err; + + if (!pskb_may_pull(skb_chk, len)) + goto err; + + ret = ip_mc_check_igmp_msg(skb_chk); + if (ret) + goto err; + + if (skb_trimmed) + *skb_trimmed = skb_chk; + /* free now unneeded clone */ + else if (skb_chk != skb) + kfree_skb(skb_chk); + + ret = 0; + +err: + if (ret && skb_chk && skb_chk != skb) + kfree_skb(skb_chk); + + return ret; +} + +/** + * 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 transport header 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). + * + * Caller needs to set the skb network header and free any returned skb if it + * differs from the provided skb. + */ +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. */ @@ -1353,6 +1539,9 @@ static void ip_mc_rejoin_groups(struct in_device *in_dev) for_each_pmc_rtnl(in_dev, im) { if (im->multiaddr == IGMP_ALL_HOSTS) continue; + if (ipv4_is_local_multicast(im->multiaddr) && + !sysctl_igmp_llm_reports) + continue; /* a failover is happening and switches * must be notified immediately @@ -1937,7 +2126,7 @@ int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr) ASSERT_RTNL(); in_dev = ip_mc_find_dev(net, imr); - if (!in_dev) { + if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) { ret = -ENODEV; goto out; } @@ -1958,7 +2147,8 @@ int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr) *imlp = iml->next_rcu; - ip_mc_dec_group(in_dev, group); + if (in_dev) + ip_mc_dec_group(in_dev, group); /* decrease mem now to avoid the memleak warning */ atomic_sub(sizeof(*iml), &sk->sk_omem_alloc); @@ -2203,11 +2393,11 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf, struct ip_sf_socklist *psl; struct net *net = sock_net(sk); + ASSERT_RTNL(); + if (!ipv4_is_multicast(addr)) return -EINVAL; - rtnl_lock(); - imr.imr_multiaddr.s_addr = msf->imsf_multiaddr; imr.imr_address.s_addr = msf->imsf_interface; imr.imr_ifindex = 0; @@ -2228,7 +2418,6 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf, goto done; msf->imsf_fmode = pmc->sfmode; psl = rtnl_dereference(pmc->sflist); - rtnl_unlock(); if (!psl) { len = 0; count = 0; @@ -2247,7 +2436,6 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf, return -EFAULT; return 0; done: - rtnl_unlock(); return err; } @@ -2261,6 +2449,8 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf, struct inet_sock *inet = inet_sk(sk); struct ip_sf_socklist *psl; + ASSERT_RTNL(); + psin = (struct sockaddr_in *)&gsf->gf_group; if (psin->sin_family != AF_INET) return -EINVAL; @@ -2268,8 +2458,6 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf, if (!ipv4_is_multicast(addr)) return -EINVAL; - rtnl_lock(); - err = -EADDRNOTAVAIL; for_each_pmc_rtnl(inet, pmc) { @@ -2281,7 +2469,6 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf, goto done; gsf->gf_fmode = pmc->sfmode; psl = rtnl_dereference(pmc->sflist); - rtnl_unlock(); count = psl ? psl->sl_count : 0; copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc; gsf->gf_numsrc = count; @@ -2301,7 +2488,6 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf, } return 0; done: - rtnl_unlock(); return err; } @@ -2380,7 +2566,7 @@ void ip_mc_drop_socket(struct sock *sk) } /* called with rcu_read_lock() */ -int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto) +int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto) { struct ip_mc_list *im; struct ip_mc_list __rcu **mc_hash; |