int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) { const struct inet6_protocol *ipprot; ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]); if (ipprot && ipprot->early_demux) ipprot->early_demux(skb); } if (!skb_valid_dst(skb)) ip6_route_input(skb); return dst_input(skb); }
static void ip6_rcv_finish_core(struct net *net, struct sock *sk, struct sk_buff *skb) { void (*edemux)(struct sk_buff *skb); if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) { const struct inet6_protocol *ipprot; ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]); if (ipprot && (edemux = READ_ONCE(ipprot->early_demux))) edemux(skb); } if (!skb_valid_dst(skb)) ip6_route_input(skb); }
int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { /* if ingress device is enslaved to an L3 master device pass the * skb to its handler for processing */ skb = l3mdev_ip6_rcv(skb); if (!skb) return NET_RX_SUCCESS; if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) { const struct inet6_protocol *ipprot; ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]); if (ipprot && ipprot->early_demux) ipprot->early_demux(skb); } if (!skb_valid_dst(skb)) 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(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(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_valid_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; __IP6_ADD_STATS(net, idev, IPSTATS_MIB_NOECTPKTS + (ipv6_get_dsfield(hdr) & INET_ECN_MASK), max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs)); /* * 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; /* RFC4291 Errata ID: 3480 * Interface-Local scope spans only a single interface on a * node and is useful only for loopback transmission of * multicast. Packets with interface-local scope received * from another node must be discarded. */ if (!(skb->pkt_type == PACKET_LOOPBACK || dev->flags & IFF_LOOPBACK) && ipv6_addr_is_multicast(&hdr->daddr) && IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1) goto err; /* If enabled, drop unicast packets that were encapsulated in link-layer * multicast or broadcast to protected against the so-called "hole-196" * attack in 802.11 wireless. */ if (!ipv6_addr_is_multicast(&hdr->daddr) && (skb->pkt_type == PACKET_BROADCAST || skb->pkt_type == PACKET_MULTICAST) && idev->cnf.drop_unicast_in_l2_multicast) goto err; /* RFC4291 2.7 * Nodes must not originate a packet to a multicast address whose scope * field contains the reserved value 0; if such a packet is received, it * must be silently dropped. */ if (ipv6_addr_is_multicast(&hdr->daddr) && IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0) goto err; /* * RFC4291 2.7 * Multicast addresses must not be used as source addresses in IPv6 * packets or appear in any Routing header. */ if (ipv6_addr_is_multicast(&hdr->saddr)) 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(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS); goto drop; } if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { __IP6_INC_STATS(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(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, net, NULL, skb, dev, NULL, ip6_rcv_finish); err: __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); drop: rcu_read_unlock(); kfree_skb(skb); return NET_RX_DROP; }
static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) { const struct iphdr *iph = ip_hdr(skb); struct rtable *rt; if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && !skb->sk && !ip_is_fragment(iph)) { const struct net_protocol *ipprot; int protocol = iph->protocol; ipprot = rcu_dereference(inet_protos[protocol]); if (ipprot && ipprot->early_demux) { ipprot->early_demux(skb); /* must reload iph, skb->head might have changed */ iph = ip_hdr(skb); } } /* * Initialise the virtual path cache for the packet. It describes * how the packet travels inside Linux networking. */ if (!skb_valid_dst(skb)) { int err = ip_route_input_noref(skb, iph->daddr, iph->saddr, iph->tos, skb->dev); if (unlikely(err)) { if (err == -EXDEV) NET_INC_STATS_BH(net, LINUX_MIB_IPRPFILTER); goto drop; } } #ifdef CONFIG_IP_ROUTE_CLASSID if (unlikely(skb_dst(skb)->tclassid)) { struct ip_rt_acct *st = this_cpu_ptr(ip_rt_acct); u32 idx = skb_dst(skb)->tclassid; st[idx&0xFF].o_packets++; st[idx&0xFF].o_bytes += skb->len; st[(idx>>16)&0xFF].i_packets++; st[(idx>>16)&0xFF].i_bytes += skb->len; } #endif if (iph->ihl > 5 && ip_rcv_options(skb)) goto drop; rt = skb_rtable(skb); if (rt->rt_type == RTN_MULTICAST) { IP_UPD_PO_STATS_BH(net, IPSTATS_MIB_INMCAST, skb->len); } else if (rt->rt_type == RTN_BROADCAST) { IP_UPD_PO_STATS_BH(net, IPSTATS_MIB_INBCAST, skb->len); } else if (skb->pkt_type == PACKET_BROADCAST || skb->pkt_type == PACKET_MULTICAST) { struct in_device *in_dev = __in_dev_get_rcu(skb->dev); /* RFC 1122 3.3.6: * * When a host sends a datagram to a link-layer broadcast * address, the IP destination address MUST be a legal IP * broadcast or IP multicast address. * * A host SHOULD silently discard a datagram that is received * via a link-layer broadcast (see Section 2.4) but does not * specify an IP multicast or broadcast destination address. * * This doesn't explicitly say L2 *broadcast*, but broadcast is * in a way a form of multicast and the most common use case for * this is 802.11 protecting against cross-station spoofing (the * so-called "hole-196" attack) so do it for both. */ if (in_dev && IN_DEV_ORCONF(in_dev, DROP_UNICAST_IN_L2_MULTICAST)) goto drop; } return dst_input(skb); drop: kfree_skb(skb); return NET_RX_DROP; }