v4.19.13 snapshot.
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
new file mode 100644
index 0000000..6b74523
--- /dev/null
+++ b/net/ipv6/ip6_input.c
@@ -0,0 +1,510 @@
+/*
+ * 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>
+#include <net/inet_ecn.h>
+#include <net/dst_metadata.h>
+
+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;
+ ip6_rcv_finish_core(net, sk, skb);
+
+ return dst_input(skb);
+}
+
+static void ip6_sublist_rcv_finish(struct list_head *head)
+{
+ struct sk_buff *skb, *next;
+
+ list_for_each_entry_safe(skb, next, head, list)
+ dst_input(skb);
+}
+
+static void ip6_list_rcv_finish(struct net *net, struct sock *sk,
+ struct list_head *head)
+{
+ struct dst_entry *curr_dst = NULL;
+ struct sk_buff *skb, *next;
+ struct list_head sublist;
+
+ INIT_LIST_HEAD(&sublist);
+ list_for_each_entry_safe(skb, next, head, list) {
+ struct dst_entry *dst;
+
+ skb_list_del_init(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)
+ continue;
+ ip6_rcv_finish_core(net, sk, skb);
+ dst = skb_dst(skb);
+ if (curr_dst != dst) {
+ /* dispatch old sublist */
+ if (!list_empty(&sublist))
+ ip6_sublist_rcv_finish(&sublist);
+ /* start new sublist */
+ INIT_LIST_HEAD(&sublist);
+ curr_dst = dst;
+ }
+ list_add_tail(&skb->list, &sublist);
+ }
+ /* dispatch final sublist */
+ ip6_sublist_rcv_finish(&sublist);
+}
+
+static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev,
+ struct net *net)
+{
+ const struct ipv6hdr *hdr;
+ u32 pkt_len;
+ struct inet6_dev *idev;
+
+ if (skb->pkt_type == PACKET_OTHERHOST) {
+ kfree_skb(skb);
+ return NULL;
+ }
+
+ 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
+ * The loopback address must not be used as the source address in IPv6
+ * packets that are sent outside of a single node. [..]
+ * A packet received on an interface with a destination address
+ * of loopback must be dropped.
+ */
+ if ((ipv6_addr_loopback(&hdr->saddr) ||
+ ipv6_addr_loopback(&hdr->daddr)) &&
+ !(dev->flags & IFF_LOOPBACK))
+ 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 NULL;
+ }
+ }
+
+ rcu_read_unlock();
+
+ /* Must drop socket now because of tproxy. */
+ skb_orphan(skb);
+
+ return skb;
+err:
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
+drop:
+ rcu_read_unlock();
+ kfree_skb(skb);
+ return NULL;
+}
+
+int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct net *net = dev_net(skb->dev);
+
+ skb = ip6_rcv_core(skb, dev, net);
+ if (skb == NULL)
+ return NET_RX_DROP;
+ return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
+ net, NULL, skb, dev, NULL,
+ ip6_rcv_finish);
+}
+
+static void ip6_sublist_rcv(struct list_head *head, struct net_device *dev,
+ struct net *net)
+{
+ NF_HOOK_LIST(NFPROTO_IPV6, NF_INET_PRE_ROUTING, net, NULL,
+ head, dev, NULL, ip6_rcv_finish);
+ ip6_list_rcv_finish(net, NULL, head);
+}
+
+/* Receive a list of IPv6 packets */
+void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
+ struct net_device *orig_dev)
+{
+ struct net_device *curr_dev = NULL;
+ struct net *curr_net = NULL;
+ struct sk_buff *skb, *next;
+ struct list_head sublist;
+
+ INIT_LIST_HEAD(&sublist);
+ list_for_each_entry_safe(skb, next, head, list) {
+ struct net_device *dev = skb->dev;
+ struct net *net = dev_net(dev);
+
+ skb_list_del_init(skb);
+ skb = ip6_rcv_core(skb, dev, net);
+ if (skb == NULL)
+ continue;
+
+ if (curr_dev != dev || curr_net != net) {
+ /* dispatch old sublist */
+ if (!list_empty(&sublist))
+ ip6_sublist_rcv(&sublist, curr_dev, curr_net);
+ /* start new sublist */
+ INIT_LIST_HEAD(&sublist);
+ curr_dev = dev;
+ curr_net = net;
+ }
+ list_add_tail(&skb->list, &sublist);
+ }
+ /* dispatch final sublist */
+ ip6_sublist_rcv(&sublist, curr_dev, curr_net);
+}
+
+/*
+ * Deliver the packet to the host
+ */
+
+
+static int ip6_input_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ const struct inet6_protocol *ipprot;
+ struct inet6_dev *idev;
+ unsigned int nhoff;
+ int nexthdr;
+ bool raw;
+ bool have_final = false;
+
+ /*
+ * 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];
+
+resubmit_final:
+ raw = raw6_local_deliver(skb, nexthdr);
+ ipprot = rcu_dereference(inet6_protos[nexthdr]);
+ if (ipprot) {
+ int ret;
+
+ if (have_final) {
+ if (!(ipprot->flags & INET6_PROTO_FINAL)) {
+ /* Once we've seen a final protocol don't
+ * allow encapsulation on any non-final
+ * ones. This allows foo in UDP encapsulation
+ * to work.
+ */
+ goto discard;
+ }
+ } else if (ipprot->flags & INET6_PROTO_FINAL) {
+ const struct ipv6hdr *hdr;
+
+ /* Only do this once for first final protocol */
+ have_final = true;
+
+ /* 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, skb_network_header_len(skb)))
+ 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) {
+ if (ipprot->flags & INET6_PROTO_FINAL) {
+ /* Not an extension header, most likely UDP
+ * encapsulation. Use return value as nexthdr
+ * protocol not nhoff (which presumably is
+ * not set by handler).
+ */
+ nexthdr = ret;
+ goto resubmit_final;
+ } else {
+ goto resubmit;
+ }
+ } else if (ret == 0) {
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
+ }
+ } else {
+ if (!raw) {
+ if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+ __IP6_INC_STATS(net, idev,
+ IPSTATS_MIB_INUNKNOWNPROTOS);
+ icmpv6_send(skb, ICMPV6_PARAMPROB,
+ ICMPV6_UNK_NEXTHDR, nhoff);
+ }
+ kfree_skb(skb);
+ } else {
+ __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
+ consume_skb(skb);
+ }
+ }
+ rcu_read_unlock();
+ return 0;
+
+discard:
+ __IP6_INC_STATS(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,
+ dev_net(skb->dev), NULL, skb, skb->dev, NULL,
+ ip6_input_finish);
+}
+EXPORT_SYMBOL_GPL(ip6_input);
+
+int ip6_mc_input(struct sk_buff *skb)
+{
+ const struct ipv6hdr *hdr;
+ bool deliver;
+
+ __IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev),
+ __in6_dev_get_safely(skb->dev), 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_LOOPBACK|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->flags & IP6SKB_ROUTERALERT)) {
+ /* Check if this is a mld message */
+ u8 nexthdr = hdr->nexthdr;
+ __be16 frag_off;
+ int offset;
+
+ /* Check if the value of Router Alert
+ * is for MLD (0x0000).
+ */
+ if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
+ deliver = false;
+
+ if (!ipv6_ext_hdr(nexthdr)) {
+ /* BUG */
+ goto out;
+ }
+ offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
+ &nexthdr, &frag_off);
+ if (offset < 0)
+ goto out;
+
+ if (ipv6_is_mld(skb, nexthdr, offset))
+ deliver = true;
+
+ 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;
+}