/* * IPv6 input * Linux INET6 implementation * * Authors: * Pedro Roque <roque@di.fc.ul.pt> * Ian P. Morris <I.P.Morris@soton.ac.uk> * * Based in linux/net/ipv4/ip_input.c * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ /* Changes * * Mitsuru KANDA @USAGI and * YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs(). */ #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/sockios.h> #include <linux/net.h> #include <linux/netdevice.h> #include <linux/in6.h> #include <linux/icmpv6.h> #include <linux/mroute6.h> #include <linux/slab.h> #include <linux/netfilter.h> #include <linux/netfilter_ipv6.h> #include <net/sock.h> #include <net/snmp.h> #include <net/ipv6.h> #include <net/protocol.h> #include <net/transp_v6.h> #include <net/rawv6.h> #include <net/ndisc.h> #include <net/ip6_route.h> #include <net/addrconf.h> #include <net/xfrm.h> inline int ip6_rcv_finish( struct sk_buff *skb) { if (skb_dst(skb) == NULL) ip6_route_input(skb); return dst_input(skb); } int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct ipv6hdr *hdr; u32 pkt_len; struct inet6_dev *idev; struct net *net = dev_net(skb->dev); if (skb->pkt_type == PACKET_OTHERHOST) { kfree_skb(skb); return NET_RX_DROP; } rcu_read_lock(); idev = __in6_dev_get(skb->dev); IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len); if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL || !idev || unlikely(idev->cnf.disable_ipv6)) { IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS); goto drop; } memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); /* * Store incoming device index. When the packet will * be queued, we cannot refer to skb->dev anymore. * * BTW, when we send a packet for our own local address on a * non-loopback interface (e.g. ethX), it is being delivered * via the loopback interface (lo) here; skb->dev = loopback_dev. * It, however, should be considered as if it is being * arrived via the sending interface (ethX), because of the * nature of scoping architecture. --yoshfuji */ IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex; if (unlikely(!pskb_may_pull(skb, sizeof(*hdr)))) goto err; hdr = ipv6_hdr(skb); if (hdr->version != 6) goto err; /* * RFC4291 2.5.3 * A packet received on an interface with a destination address * of loopback must be dropped. */ if (!(dev->flags & IFF_LOOPBACK) && ipv6_addr_loopback(&hdr->daddr)) goto err; skb->transport_header = skb->network_header + sizeof(*hdr); IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); pkt_len = ntohs(hdr->payload_len); /* pkt_len may be zero if Jumbo payload option is present */ if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) { if (pkt_len + sizeof(struct ipv6hdr) > skb->len) { IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS); goto drop; } if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); goto drop; } hdr = ipv6_hdr(skb); } if (hdr->nexthdr == NEXTHDR_HOP) { if (ipv6_parse_hopopts(skb) < 0) { IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); rcu_read_unlock(); return NET_RX_DROP; } } rcu_read_unlock(); /* Must drop socket now because of tproxy. */ skb_orphan(skb); return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish); err: IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS); drop: rcu_read_unlock(); kfree_skb(skb); return NET_RX_DROP; } /* * Deliver the packet to the host */ static int ip6_input_finish(struct sk_buff *skb) { const struct inet6_protocol *ipprot; unsigned int nhoff; int nexthdr, raw; u8 hash; struct inet6_dev *idev; struct net *net = dev_net(skb_dst(skb)->dev); /* * Parse extension headers */ rcu_read_lock(); resubmit: idev = ip6_dst_idev(skb_dst(skb)); if (!pskb_pull(skb, skb_transport_offset(skb))) goto discard; nhoff = IP6CB(skb)->nhoff; nexthdr = skb_network_header(skb)[nhoff]; raw = raw6_local_deliver(skb, nexthdr); hash = nexthdr & (MAX_INET_PROTOS - 1); if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) { int ret; if (ipprot->flags & INET6_PROTO_FINAL) { struct ipv6hdr *hdr; /* Free reference early: we don't need it any more, and it may hold ip_conntrack module loaded indefinitely. */ nf_reset(skb); skb_postpull_rcsum(skb, skb_network_header(skb), skb_network_header_len(skb)); hdr = ipv6_hdr(skb); if (ipv6_addr_is_multicast(&hdr->daddr) && !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, &hdr->saddr) && !ipv6_is_mld(skb, nexthdr)) goto discard; } if (!(ipprot->flags & INET6_PROTO_NOPOLICY) && !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard; ret = ipprot->handler(skb); if (ret > 0) goto resubmit; else if (ret == 0) IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS); } else { if (!raw) { if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INUNKNOWNPROTOS); icmpv6_send(skb, ICMPV6_PARAMPROB, ICMPV6_UNK_NEXTHDR, nhoff); } } else IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS); kfree_skb(skb); } rcu_read_unlock(); return 0; discard: IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS); rcu_read_unlock(); kfree_skb(skb); return 0; } int ip6_input(struct sk_buff *skb) { return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish); } int ip6_mc_input(struct sk_buff *skb) { struct ipv6hdr *hdr; int deliver; IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST, skb->len); hdr = ipv6_hdr(skb); deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); #ifdef CONFIG_IPV6_MROUTE /* * IPv6 multicast router mode is now supported ;) */ if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) && likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { /* * Okay, we try to forward - split and duplicate * packets. */ struct sk_buff *skb2; struct inet6_skb_parm *opt = IP6CB(skb); /* Check for MLD */ if (unlikely(opt->ra)) { /* Check if this is a mld message */ u8 *ptr = skb_network_header(skb) + opt->ra; struct icmp6hdr *icmp6; u8 nexthdr = hdr->nexthdr; int offset; /* Check if the value of Router Alert * is for MLD (0x0000). */ if ((ptr[2] | ptr[3]) == 0) { deliver = 0; if (!ipv6_ext_hdr(nexthdr)) { /* BUG */ goto out; } offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr); if (offset < 0) goto out; if (nexthdr != IPPROTO_ICMPV6) goto out; if (!pskb_may_pull(skb, (skb_network_header(skb) + offset + 1 - skb->data))) goto out; icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); switch (icmp6->icmp6_type) { case ICMPV6_MGM_QUERY: case ICMPV6_MGM_REPORT: case ICMPV6_MGM_REDUCTION: case ICMPV6_MLD2_REPORT: deliver = 1; break; } goto out; } /* unknown RA - process it normally */ } if (deliver) skb2 = skb_clone(skb, GFP_ATOMIC); else { skb2 = skb; skb = NULL; } if (skb2) { ip6_mr_input(skb2); } } out: #endif if (likely(deliver)) ip6_input(skb); else { /* discard */ kfree_skb(skb); } return 0; }