[IPSEC]: Rename mode to outer_mode and add inner_mode

This patch adds a new field to xfrm states called inner_mode.  The existing
mode object is renamed to outer_mode.

This is the first part of an attempt to fix inter-family transforms.  As it
is we always use the outer family when determining which mode to use.  As a
result we may end up shoving IPv4 packets into netfilter6 and vice versa.

What we really want is to use the inner family for the first part of outbound
processing and the outer family for the second part.  For inbound processing
we'd use the opposite pairing.

I've also added a check to prevent silly combinations such as transport mode
with inter-family transforms.

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

11 files changed, 28 insertions, 17 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index f0f3318f6550..688f6f5d3285 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -186,7 +186,8 @@ struct xfrm_state
 	/* Reference to data common to all the instances of this
 	 * transformer. */
 	struct xfrm_type	*type;
-	struct xfrm_mode	*mode;
+	struct xfrm_mode	*inner_mode;
+	struct xfrm_mode	*outer_mode;
 
 	/* Security context */
 	struct xfrm_sec_ctx	*security;
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 2100c734b102..8cae60c53383 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2454,7 +2454,7 @@ static int pktgen_output_ipsec(struct sk_buff *skb, struct pktgen_dev *pkt_dev)
 	spin_lock(&x->lock);
 	iph = ip_hdr(skb);
 
-	err = x->mode->output(x, skb);
+	err = x->outer_mode->output(x, skb);
 	if (err)
 		goto error;
 	err = x->type->output(x, skb);
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index bc5dc0747cd2..5e95c8a07efb 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -91,10 +91,10 @@ int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
 
 		xfrm_vec[xfrm_nr++] = x;
 
-		if (x->mode->input(x, skb))
+		if (x->outer_mode->input(x, skb))
 			goto drop;
 
-		if (x->mode->flags & XFRM_MODE_FLAG_TUNNEL) {
+		if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
 			decaps = 1;
 			break;
 		}
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index dcbc2743069c..c4a7156962bd 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -47,7 +47,7 @@ static inline int xfrm4_output_one(struct sk_buff *skb)
 	struct iphdr *iph;
 	int err;
 
-	if (x->mode->flags & XFRM_MODE_FLAG_TUNNEL) {
+	if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
 		err = xfrm4_tunnel_check_size(skb);
 		if (err)
 			goto error_nolock;
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 1f0ea0e0371b..cc86fb110dd8 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -168,7 +168,7 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
 		/* Copy neighbout for reachability confirmation */
 		dst_prev->neighbour	= neigh_clone(rt->u.dst.neighbour);
 		dst_prev->input		= rt->u.dst.input;
-		dst_prev->output = dst_prev->xfrm->mode->afinfo->output;
+		dst_prev->output = dst_prev->xfrm->outer_mode->afinfo->output;
 		if (rt0->peer)
 			atomic_inc(&rt0->peer->refcnt);
 		x->u.rt.peer = rt0->peer;
diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index c6ee1a3ba19a..515783707e86 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -68,10 +68,10 @@ int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
 
 		xfrm_vec[xfrm_nr++] = x;
 
-		if (x->mode->input(x, skb))
+		if (x->outer_mode->input(x, skb))
 			goto drop;
 
-		if (x->mode->flags & XFRM_MODE_FLAG_TUNNEL) {
+		if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
 			decaps = 1;
 			break;
 		}
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index c9f42d1c2dff..656976760ad4 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -50,7 +50,7 @@ static inline int xfrm6_output_one(struct sk_buff *skb)
 	struct ipv6hdr *iph;
 	int err;
 
-	if (x->mode->flags & XFRM_MODE_FLAG_TUNNEL) {
+	if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
 		err = xfrm6_tunnel_check_size(skb);
 		if (err)
 			goto error_nolock;
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 324268329f69..82e27b80d07d 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -230,7 +230,7 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
 		/* Copy neighbour for reachability confirmation */
 		dst_prev->neighbour	= neigh_clone(rt->u.dst.neighbour);
 		dst_prev->input		= rt->u.dst.input;
-		dst_prev->output = dst_prev->xfrm->mode->afinfo->output;
+		dst_prev->output = dst_prev->xfrm->outer_mode->afinfo->output;
 		/* Sheit... I remember I did this right. Apparently,
 		 * it was magically lost, so this code needs audit */
 		x->u.rt6.rt6i_flags    = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 8bf71ba2345f..f4bfd6c45651 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -63,7 +63,7 @@ int xfrm_output(struct sk_buff *skb)
 				xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
 		}
 
-		err = x->mode->output(x, skb);
+		err = x->outer_mode->output(x, skb);
 		if (err)
 			goto error;
 
@@ -82,7 +82,7 @@ int xfrm_output(struct sk_buff *skb)
 		}
 		dst = skb->dst;
 		x = dst->xfrm;
-	} while (x && !(x->mode->flags & XFRM_MODE_FLAG_TUNNEL));
+	} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
 
 	err = 0;
 
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 1d66fb42c9cb..b702bd8a3893 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1941,7 +1941,7 @@ int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *first,
 			return 0;
 
 		if (strict && fl &&
-		    !(dst->xfrm->mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
+		    !(dst->xfrm->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
 		    !xfrm_state_addr_flow_check(dst->xfrm, fl, family))
 			return 0;
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 48b4a06b3d1a..224b44e31a07 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -377,8 +377,10 @@ static void xfrm_state_gc_destroy(struct xfrm_state *x)
 	kfree(x->calg);
 	kfree(x->encap);
 	kfree(x->coaddr);
-	if (x->mode)
-		xfrm_put_mode(x->mode);
+	if (x->inner_mode)
+		xfrm_put_mode(x->inner_mode);
+	if (x->outer_mode)
+		xfrm_put_mode(x->outer_mode);
 	if (x->type) {
 		x->type->destructor(x);
 		xfrm_put_type(x->type);
@@ -1947,6 +1949,14 @@ int xfrm_init_state(struct xfrm_state *x)
 		goto error;
 
 	err = -EPROTONOSUPPORT;
+	x->inner_mode = xfrm_get_mode(x->props.mode, x->sel.family);
+	if (x->inner_mode == NULL)
+		goto error;
+
+	if (!(x->inner_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
+	    family != x->sel.family)
+		goto error;
+
 	x->type = xfrm_get_type(x->id.proto, family);
 	if (x->type == NULL)
 		goto error;
@@ -1955,8 +1965,8 @@ int xfrm_init_state(struct xfrm_state *x)
 	if (err)
 		goto error;
 
-	x->mode = xfrm_get_mode(x->props.mode, family);
-	if (x->mode == NULL)
+	x->outer_mode = xfrm_get_mode(x->props.mode, family);
+	if (x->outer_mode == NULL)
 		goto error;
 
 	x->km.state = XFRM_STATE_VALID;