[IPSEC]: Merge most of the input path

As part of the work on asynchronous cryptographic operations, we need
to be able to resume from the spot where they occur.  As such, it
helps if we isolate them to one spot.

This patch moves most of the remaining family-specific processing into
the common input code.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 15 insertions, 112 deletions

diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index c0323d05ab6..e374903dacd 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -41,124 +41,26 @@ drop:
 int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
 		    int encap_type)
 {
-	int err;
-	__be32 seq;
-	struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
-	struct xfrm_state *x;
-	int xfrm_nr = 0;
-	int decaps = 0;
-	unsigned int nhoff = offsetof(struct iphdr, protocol);
-
-	seq = 0;
-	if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
-		goto drop;
-
-	do {
-		const struct iphdr *iph = ip_hdr(skb);
-
-		if (xfrm_nr == XFRM_MAX_DEPTH)
-			goto drop;
-
-		x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi,
-				      nexthdr, AF_INET);
-		if (x == NULL)
-			goto drop;
-
-		spin_lock(&x->lock);
-		if (unlikely(x->km.state != XFRM_STATE_VALID))
-			goto drop_unlock;
-
-		if ((x->encap ? x->encap->encap_type : 0) != encap_type)
-			goto drop_unlock;
-
-		if (x->props.replay_window && xfrm_replay_check(x, seq))
-			goto drop_unlock;
-
-		if (xfrm_state_check_expire(x))
-			goto drop_unlock;
-
-		nexthdr = x->type->input(x, skb);
-		if (nexthdr <= 0)
-			goto drop_unlock;
-
-		skb_network_header(skb)[nhoff] = nexthdr;
-
-		/* only the first xfrm gets the encap type */
-		encap_type = 0;
-
-		if (x->props.replay_window)
-			xfrm_replay_advance(x, seq);
-
-		x->curlft.bytes += skb->len;
-		x->curlft.packets++;
-
-		spin_unlock(&x->lock);
-
-		xfrm_vec[xfrm_nr++] = x;
-
-		if (x->inner_mode->input(x, skb))
-			goto drop;
-
-		if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
-			decaps = 1;
-			break;
-		}
-
-		err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
-		if (err < 0)
-			goto drop;
-	} while (!err);
-
-	/* 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 (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
-		goto drop;
-
-	memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec,
-	       xfrm_nr * sizeof(xfrm_vec[0]));
-	skb->sp->len += xfrm_nr;
-
-	nf_reset(skb);
+	XFRM_SPI_SKB_CB(skb)->nhoff = offsetof(struct iphdr, protocol);
+	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
+	return xfrm_input(skb, nexthdr, spi, encap_type);
+}
+EXPORT_SYMBOL(xfrm4_rcv_encap);
 
-	if (decaps) {
-		dst_release(skb->dst);
-		skb->dst = NULL;
-		netif_rx(skb);
-		return 0;
-	} else {
+int xfrm4_transport_finish(struct sk_buff *skb, int async)
+{
 #ifdef CONFIG_NETFILTER
-		__skb_push(skb, skb->data - skb_network_header(skb));
-		ip_hdr(skb)->tot_len = htons(skb->len);
-		ip_send_check(ip_hdr(skb));
+	__skb_push(skb, skb->data - skb_network_header(skb));
+	ip_hdr(skb)->tot_len = htons(skb->len);
+	ip_send_check(ip_hdr(skb));
 
-		NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
-			xfrm4_rcv_encap_finish);
-		return 0;
+	NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
+		xfrm4_rcv_encap_finish);
+	return 0;
 #else
-		return -ip_hdr(skb)->protocol;
+	return -ip_hdr(skb)->protocol;
 #endif
-	}
-
-drop_unlock:
-	spin_unlock(&x->lock);
-	xfrm_state_put(x);
-drop:
-	while (--xfrm_nr >= 0)
-		xfrm_state_put(xfrm_vec[xfrm_nr]);
-
-	kfree_skb(skb);
-	return 0;
 }
-EXPORT_SYMBOL(xfrm4_rcv_encap);
 
 /* If it's a keepalive packet, then just eat it.
  * If it's an encapsulated packet, then pass it to the
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index 80292fbf221..3b067e8b7bf 100644
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -74,6 +74,7 @@ static struct xfrm_state_afinfo xfrm4_state_afinfo = {
 	.output			= xfrm4_output,
 	.extract_input		= xfrm4_extract_input,
 	.extract_output		= xfrm4_extract_output,
+	.transport_finish	= xfrm4_transport_finish,
 };
 
 void __init xfrm4_state_init(void)