[IPV6] MIP6: Add inbound interface of routing header type 2.

Add inbound interface of routing header type 2 for Mobile IPv6.
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 61 insertions, 8 deletions

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 05afa6b1912b..8d3a0e17314d 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -43,6 +43,9 @@
 #include <net/ndisc.h>
 #include <net/ip6_route.h>
 #include <net/addrconf.h>
+#ifdef CONFIG_IPV6_MIP6
+#include <net/xfrm.h>
+#endif
 
 #include <asm/uaccess.h>
 
@@ -219,7 +222,7 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp)
 {
         struct sk_buff *skb = *skbp;
         struct inet6_skb_parm *opt = IP6CB(skb);
-        struct in6_addr *addr;
+        struct in6_addr *addr = NULL;
         struct in6_addr daddr;
         int n, i;
 
@@ -244,6 +247,23 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp)
 
 looped_back:
         if (hdr->segments_left == 0) {
+                switch (hdr->type) {
+#ifdef CONFIG_IPV6_MIP6
+                case IPV6_SRCRT_TYPE_2:
+                        /* Silently discard type 2 header unless it was
+                         * processed by own
+                         */
+                        if (!addr) {
+                                IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+                                kfree_skb(skb);
+                                return -1;
+                        }
+                        break;
+#endif
+                default:
+                        break;
+                }
+
                 opt->lastopt = skb->h.raw - skb->nh.raw;
                 opt->srcrt = skb->h.raw - skb->nh.raw;
                 skb->h.raw += (hdr->hdrlen + 1) << 3;
@@ -253,17 +273,29 @@ looped_back:
                 return 1;
         }
 
-        if (hdr->type != IPV6_SRCRT_TYPE_0) {
+        switch (hdr->type) {
+        case IPV6_SRCRT_TYPE_0:
+                if (hdr->hdrlen & 0x01) {
+                        IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+                        icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->hdrlen) - skb->nh.raw);
+                        return -1;
+                }
+                break;
+#ifdef CONFIG_IPV6_MIP6
+        case IPV6_SRCRT_TYPE_2:
+                /* Silently discard invalid RTH type 2 */
+                if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
+                        IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+                        kfree_skb(skb);
+                        return -1;
+                }
+                break;
+#endif
+        default:
                 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw);
                 return -1;
         }
-        
-        if (hdr->hdrlen & 0x01) {
-                IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
-                icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->hdrlen) - skb->nh.raw);
-                return -1;
-        }
 
         /*
          *      This is the routing header forwarding algorithm from
@@ -303,6 +335,27 @@ looped_back:
         addr = rthdr->addr;
         addr += i - 1;
 
+        switch (hdr->type) {
+#ifdef CONFIG_IPV6_MIP6
+        case IPV6_SRCRT_TYPE_2:
+                if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
+                                     (xfrm_address_t *)&skb->nh.ipv6h->saddr,
+                                     IPPROTO_ROUTING) < 0) {
+                        IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+                        kfree_skb(skb);
+                        return -1;
+                }
+                if (!ipv6_chk_home_addr(addr)) {
+                        IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
+                        kfree_skb(skb);
+                        return -1;
+                }
+                break;
+#endif
+        default:
+                break;
+        }
+
         if (ipv6_addr_is_multicast(addr)) {
                 IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
                 kfree_skb(skb);