[XFRM] STATE: Common receive function for route optimization extension headers.

XFRM_STATE_WILDRECV flag is introduced; the last resort state is set
it and receives packet which is not route optimized but uses such
extension headers i.e. Mobile IPv6 signaling (binding update and
acknowledgement).  A node enabled Mobile IPv6 adds the state.

Based on MIPL2 kernel patch.

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>

5 files changed, 113 insertions, 0 deletions

diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index 66343d3d4b91..a7c9e4cfb15b 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -256,6 +256,7 @@ struct xfrm_usersa_info {
 #define XFRM_STATE_NOECN        1
 #define XFRM_STATE_DECAP_DSCP   2
 #define XFRM_STATE_NOPMTUDISC   4
+#define XFRM_STATE_WILDRECV     8
 };
 
 struct xfrm_usersa_id {
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index eed48f832ce1..0d735a5aba61 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -955,6 +955,8 @@ extern int xfrm4_tunnel_register(struct xfrm_tunnel *handler);
 extern int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler);
 extern int xfrm6_rcv_spi(struct sk_buff *skb, u32 spi);
 extern int xfrm6_rcv(struct sk_buff **pskb);
+extern int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
+                            xfrm_address_t *saddr, u8 proto);
 extern int xfrm6_tunnel_register(struct xfrm6_tunnel *handler);
 extern int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler);
 extern u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr);
diff --git a/net/ipv6/ipv6_syms.c b/net/ipv6/ipv6_syms.c
index e1a741612888..7b7b90d9c3d0 100644
--- a/net/ipv6/ipv6_syms.c
+++ b/net/ipv6/ipv6_syms.c
@@ -31,6 +31,7 @@ EXPORT_SYMBOL(ipv6_chk_addr);
 EXPORT_SYMBOL(in6_dev_finish_destroy);
 #ifdef CONFIG_XFRM
 EXPORT_SYMBOL(xfrm6_rcv);
+EXPORT_SYMBOL(xfrm6_input_addr);
 EXPORT_SYMBOL(xfrm6_find_1stfragopt);
 #endif
 EXPORT_SYMBOL(rt6_lookup);
diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index ee2f6b3908b6..a40a05789013 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -138,3 +138,111 @@ int xfrm6_rcv(struct sk_buff **pskb)
 {
         return xfrm6_rcv_spi(*pskb, 0);
 }
+
+int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
+                     xfrm_address_t *saddr, u8 proto)
+{
+        struct xfrm_state *x = NULL;
+        int wildcard = 0;
+        struct in6_addr any;
+        xfrm_address_t *xany;
+        struct xfrm_state *xfrm_vec_one = NULL;
+        int nh = 0;
+        int i = 0;
+
+        ipv6_addr_set(&any, 0, 0, 0, 0);
+        xany = (xfrm_address_t *)&any;
+
+        for (i = 0; i < 3; i++) {
+                xfrm_address_t *dst, *src;
+                switch (i) {
+                case 0:
+                        dst = daddr;
+                        src = saddr;
+                        break;
+                case 1:
+                        /* lookup state with wild-card source address */
+                        wildcard = 1;
+                        dst = daddr;
+                        src = xany;
+                        break;
+                case 2:
+                default:
+                        /* lookup state with wild-card addresses */
+                        wildcard = 1; /* XXX */
+                        dst = xany;
+                        src = xany;
+                        break;
+                }
+
+                x = xfrm_state_lookup_byaddr(dst, src, proto, AF_INET6);
+                if (!x)
+                        continue;
+
+                spin_lock(&x->lock);
+
+                if (wildcard) {
+                        if ((x->props.flags & XFRM_STATE_WILDRECV) == 0) {
+                                spin_unlock(&x->lock);
+                                xfrm_state_put(x);
+                                x = NULL;
+                                continue;
+                        }
+                }
+
+                if (unlikely(x->km.state != XFRM_STATE_VALID)) {
+                        spin_unlock(&x->lock);
+                        xfrm_state_put(x);
+                        x = NULL;
+                        continue;
+                }
+                if (xfrm_state_check_expire(x)) {
+                        spin_unlock(&x->lock);
+                        xfrm_state_put(x);
+                        x = NULL;
+                        continue;
+                }
+
+                nh = x->type->input(x, skb);
+                if (nh <= 0) {
+                        spin_unlock(&x->lock);
+                        xfrm_state_put(x);
+                        x = NULL;
+                        continue;
+                }
+
+                x->curlft.bytes += skb->len;
+                x->curlft.packets++;
+
+                spin_unlock(&x->lock);
+
+                xfrm_vec_one = x;
+                break;
+        }
+
+        if (!xfrm_vec_one)
+                goto drop;
+
+        /* Allocate new secpath or COW existing one. */
+        if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
+                struct sec_path *sp;
+                sp = secpath_dup(skb->sp);
+                if (!sp)
+                        goto drop;
+                if (skb->sp)
+                        secpath_put(skb->sp);
+                skb->sp = sp;
+        }
+
+        if (1 + skb->sp->len > XFRM_MAX_DEPTH)
+                goto drop;
+
+        skb->sp->xvec[skb->sp->len] = xfrm_vec_one;
+        skb->sp->len ++;
+
+        return 1;
+drop:
+        if (xfrm_vec_one)
+                xfrm_state_put(xfrm_vec_one);
+        return -1;
+}
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 11f480b12952..f05371556cce 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -352,6 +352,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
         list_for_each_entry(x, xfrm_state_bydst+h, bydst) {
                 if (x->props.family == family &&
                     x->props.reqid == tmpl->reqid &&
+                    !(x->props.flags & XFRM_STATE_WILDRECV) &&
                     xfrm_state_addr_check(x, daddr, saddr, family) &&
                     tmpl->mode == x->props.mode &&
                     tmpl->id.proto == x->id.proto &&