diff options
Diffstat (limited to 'net/ipv6/ip6_input.c')
| -rw-r--r-- | net/ipv6/ip6_input.c | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c new file mode 100644 index 00000000..027c7ff6 --- /dev/null +++ b/net/ipv6/ip6_input.c @@ -0,0 +1,335 @@ +/* + * 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) +{ + const 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) { + const 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) +{ + const 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; +} |