/* * IPv6 input * Linux INET6 implementation * * Authors: * Pedro Roque <roque@di.fc.ul.pt> * Ian P. Morris <I.P.Morris@soton.ac.uk> * * $Id: ip6_input.c,v 1.19 2000/12/13 18:31:50 davem Exp $ * * 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/sched.h> #include <linux/net.h> #include <linux/netdevice.h> #include <linux/in6.h> #include <linux/icmpv6.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> static inline int ip6_rcv_finish( struct sk_buff *skb) { if (skb->dst == 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; if (skb->pkt_type == PACKET_OTHERHOST) goto drop; IP6_INC_STATS_BH(IPSTATS_MIB_INRECEIVES); if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS); goto out; } /* * 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 ? ((struct rt6_info *)skb->dst)->rt6i_idev->dev->ifindex : dev->ifindex; if (skb->len < sizeof(struct ipv6hdr)) goto err; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) { IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); goto drop; } hdr = skb->nh.ipv6h; if (hdr->version != 6) goto err; 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) goto truncated; if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); goto drop; } hdr = skb->nh.ipv6h; } if (hdr->nexthdr == NEXTHDR_HOP) { skb->h.raw = (u8*)(hdr+1); if (ipv6_parse_hopopts(skb, offsetof(struct ipv6hdr, nexthdr)) < 0) { IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); return 0; } hdr = skb->nh.ipv6h; } return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish); truncated: IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS); err: IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); drop: kfree_skb(skb); out: return 0; } /* * Deliver the packet to the host */ static inline int ip6_input_finish(struct sk_buff *skb) { struct inet6_protocol *ipprot; struct sock *raw_sk; unsigned int nhoff; int nexthdr; u8 hash; skb->h.raw = skb->nh.raw + sizeof(struct ipv6hdr); /* * Parse extension headers */ nexthdr = skb->nh.ipv6h->nexthdr; nhoff = offsetof(struct ipv6hdr, nexthdr); /* Skip hop-by-hop options, they are already parsed. */ if (nexthdr == NEXTHDR_HOP) { nhoff = sizeof(struct ipv6hdr); nexthdr = skb->h.raw[0]; skb->h.raw += (skb->h.raw[1]+1)<<3; } rcu_read_lock(); resubmit: if (!pskb_pull(skb, skb->h.raw - skb->data)) goto discard; nexthdr = skb->nh.raw[nhoff]; raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]); if (raw_sk && !ipv6_raw_deliver(skb, nexthdr)) raw_sk = NULL; 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->nh.raw, skb->h.raw - skb->nh.raw); hdr = skb->nh.ipv6h; 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, &nhoff); if (ret > 0) goto resubmit; else if (ret == 0) IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS); } else { if (!raw_sk) { if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { IP6_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS); icmpv6_send(skb, ICMPV6_PARAMPROB, ICMPV6_UNK_NEXTHDR, nhoff, skb->dev); } } else IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS); kfree_skb(skb); } rcu_read_unlock(); return 0; discard: IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS); rcu_read_unlock(); kfree_skb(skb); return 0; } int ip6_input(struct sk_buff *skb) { return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish); } int ip6_mc_input(struct sk_buff *skb) { struct ipv6hdr *hdr; int deliver; IP6_INC_STATS_BH(IPSTATS_MIB_INMCASTPKTS); hdr = skb->nh.ipv6h; deliver = likely(!(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI))) || ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL); /* * IPv6 multicast router mode isnt currently supported. */ #if 0 if (ipv6_config.multicast_route) { int addr_type; addr_type = ipv6_addr_type(&hdr->daddr); if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) { struct sk_buff *skb2; struct dst_entry *dst; dst = skb->dst; if (deliver) { skb2 = skb_clone(skb, GFP_ATOMIC); dst_output(skb2); } else { dst_output(skb); return 0; } } } #endif if (likely(deliver)) { ip6_input(skb); return 0; } /* discard */ kfree_skb(skb); return 0; }