[IPSEC]: Move integrity stat collection into xfrm_input

Similar to the moving out of the replay processing on the output, this
patch moves the integrity stat collectin from x->type->input into
xfrm_input.

This would eventually allow transforms such as AH/ESP to be lockless.

The error value EBADMSG (currently unused in the crypto layer) is used
to indicate a failed integrity check.  In future this error can be
directly returned by the crypto layer once we switch to aead
algorithms.

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

5 files changed, 15 insertions, 12 deletions

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 5fc346d8b566..a989d29b44ea 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -177,9 +177,8 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
                 err = ah_mac_digest(ahp, skb, ah->auth_data);
                 if (err)
                         goto out;
-                err = -EINVAL;
                 if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len)) {
-                        x->stats.integrity_failed++;
+                        err = -EBADMSG;
                         goto out;
                 }
         }
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 1738113268bc..3350a7d50669 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -163,7 +163,7 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
         u8 nexthdr[2];
         struct scatterlist *sg;
         int padlen;
-        int err;
+        int err = -EINVAL;
 
         if (!pskb_may_pull(skb, sizeof(*esph)))
                 goto out;
@@ -183,13 +183,14 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
                         BUG();
 
                 if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) {
-                        x->stats.integrity_failed++;
+                        err = -EBADMSG;
                         goto out;
                 }
         }
 
-        if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0)
+        if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
                 goto out;
+        nfrags = err;
 
         skb->ip_summed = CHECKSUM_NONE;
 
@@ -202,6 +203,7 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
         sg = &esp->sgbuf[0];
 
         if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
+                err = -ENOMEM;
                 sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
                 if (!sg)
                         goto out;
@@ -214,11 +216,12 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
         if (unlikely(sg != &esp->sgbuf[0]))
                 kfree(sg);
         if (unlikely(err))
-                return err;
+                goto out;
 
         if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
                 BUG();
 
+        err = -EINVAL;
         padlen = nexthdr[0];
         if (padlen+2 >= elen)
                 goto out;
@@ -276,7 +279,7 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
         return nexthdr[1];
 
 out:
-        return -EINVAL;
+        return err;
 }
 
 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 4eaf55072b1b..d4b59ecb0b57 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -379,10 +379,9 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
                 err = ah_mac_digest(ahp, skb, ah->auth_data);
                 if (err)
                         goto free_out;
-                err = -EINVAL;
                 if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len)) {
                         LIMIT_NETDEBUG(KERN_WARNING "ipsec ah authentication error\n");
-                        x->stats.integrity_failed++;
+                        err = -EBADMSG;
                         goto free_out;
                 }
         }
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 444053254676..096974ba6420 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -177,8 +177,7 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
                         BUG();
 
                 if (unlikely(memcmp(esp->auth.work_icv, sum, alen))) {
-                        x->stats.integrity_failed++;
-                        ret = -EINVAL;
+                        ret = -EBADMSG;
                         goto out;
                 }
         }
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 587f3474ed3d..b7d68eb9434c 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -147,8 +147,11 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
                         goto drop_unlock;
 
                 nexthdr = x->type->input(x, skb);
-                if (nexthdr <= 0)
+                if (nexthdr <= 0) {
+                        if (nexthdr == -EBADMSG)
+                                x->stats.integrity_failed++;
                         goto drop_unlock;
+                }
 
                 skb_network_header(skb)[nhoff] = nexthdr;