1 files changed, 35 insertions, 24 deletions

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 31041127eeb8..47c95e8ef045 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -21,13 +21,14 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
         struct blkcipher_desc desc;
         struct esp_data *esp;
         struct sk_buff *trailer;
+        u8 *tail;
         int blksize;
         int clen;
         int alen;
         int nfrags;
 
         /* Strip IP+ESP header. */
-        __skb_pull(skb, skb->h.raw - skb->data);
+        __skb_pull(skb, skb_transport_offset(skb));
         /* Now skb is pure payload to encrypt */
 
         err = -ENOMEM;
@@ -49,19 +50,21 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
                 goto error;
 
         /* Fill padding... */
+        tail = skb_tail_pointer(trailer);
         do {
                 int i;
                 for (i=0; i<clen-skb->len - 2; i++)
-                        *(u8*)(trailer->tail + i) = i+1;
+                        tail[i] = i + 1;
         } while (0);
-        *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
+        tail[clen - skb->len - 2] = (clen - skb->len) - 2;
         pskb_put(skb, trailer, clen - skb->len);
 
-        __skb_push(skb, skb->data - skb->nh.raw);
-        top_iph = skb->nh.iph;
-        esph = (struct ip_esp_hdr *)(skb->nh.raw + top_iph->ihl*4);
+        __skb_push(skb, skb->data - skb_network_header(skb));
+        top_iph = ip_hdr(skb);
+        esph = (struct ip_esp_hdr *)(skb_network_header(skb) +
+                                     top_iph->ihl * 4);
         top_iph->tot_len = htons(skb->len + alen);
-        *(u8*)(trailer->tail - 1) = top_iph->protocol;
+        *(skb_tail_pointer(trailer) - 1) = top_iph->protocol;
 
         /* this is non-NULL only with UDP Encapsulation */
         if (x->encap) {
@@ -217,12 +220,12 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 
         /* ... check padding bits here. Silly. :-) */
 
-        iph = skb->nh.iph;
+        iph = ip_hdr(skb);
         ihl = iph->ihl * 4;
 
         if (x->encap) {
                 struct xfrm_encap_tmpl *encap = x->encap;
-                struct udphdr *uh = (void *)(skb->nh.raw + ihl);
+                struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
 
                 /*
                  * 1) if the NAT-T peer's IP or port changed then
@@ -260,7 +263,8 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 
         iph->protocol = nexthdr[1];
         pskb_trim(skb, skb->len - alen - padlen - 2);
-        skb->h.raw = __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen) - ihl;
+        __skb_pull(skb, sizeof(*esph) + esp->conf.ivlen);
+        skb_set_transport_header(skb, -ihl);
 
         return 0;
 
@@ -268,32 +272,33 @@ out:
         return -EINVAL;
 }
 
-static u32 esp4_get_max_size(struct xfrm_state *x, int mtu)
+static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
 {
         struct esp_data *esp = x->data;
         u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);
-        int enclen = 0;
+        u32 align = max_t(u32, blksize, esp->conf.padlen);
+        u32 rem;
+
+        mtu -= x->props.header_len + esp->auth.icv_trunc_len;
+        rem = mtu & (align - 1);
+        mtu &= ~(align - 1);
 
         switch (x->props.mode) {
         case XFRM_MODE_TUNNEL:
-                mtu = ALIGN(mtu +2, blksize);
                 break;
         default:
         case XFRM_MODE_TRANSPORT:
                 /* The worst case */
-                mtu = ALIGN(mtu + 2, 4) + blksize - 4;
+                mtu -= blksize - 4;
+                mtu += min_t(u32, blksize - 4, rem);
                 break;
         case XFRM_MODE_BEET:
                 /* The worst case. */
-                enclen = IPV4_BEET_PHMAXLEN;
-                mtu = ALIGN(mtu + enclen + 2, blksize);
+                mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem);
                 break;
         }
 
-        if (esp->conf.padlen)
-                mtu = ALIGN(mtu, esp->conf.padlen);
-
-        return mtu + x->props.header_len + esp->auth.icv_trunc_len - enclen;
+        return mtu - 2;
 }
 
 static void esp4_err(struct sk_buff *skb, u32 info)
@@ -302,8 +307,8 @@ static void esp4_err(struct sk_buff *skb, u32 info)
         struct ip_esp_hdr *esph = (struct ip_esp_hdr*)(skb->data+(iph->ihl<<2));
         struct xfrm_state *x;
 
-        if (skb->h.icmph->type != ICMP_DEST_UNREACH ||
-            skb->h.icmph->code != ICMP_FRAG_NEEDED)
+        if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
+            icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
                 return;
 
         x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET);
@@ -336,6 +341,7 @@ static int esp_init_state(struct xfrm_state *x)
 {
         struct esp_data *esp = NULL;
         struct crypto_blkcipher *tfm;
+        u32 align;
 
         /* null auth and encryption can have zero length keys */
         if (x->aalg) {
@@ -402,6 +408,8 @@ static int esp_init_state(struct xfrm_state *x)
         x->props.header_len = sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
         if (x->props.mode == XFRM_MODE_TUNNEL)
                 x->props.header_len += sizeof(struct iphdr);
+        else if (x->props.mode == XFRM_MODE_BEET)
+                x->props.header_len += IPV4_BEET_PHMAXLEN;
         if (x->encap) {
                 struct xfrm_encap_tmpl *encap = x->encap;
 
@@ -417,7 +425,10 @@ static int esp_init_state(struct xfrm_state *x)
                 }
         }
         x->data = esp;
-        x->props.trailer_len = esp4_get_max_size(x, 0) - x->props.header_len;
+        align = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);
+        if (esp->conf.padlen)
+                align = max_t(u32, align, esp->conf.padlen);
+        x->props.trailer_len = align + 1 + esp->auth.icv_trunc_len;
         return 0;
 
 error:
@@ -434,7 +445,7 @@ static struct xfrm_type esp_type =
         .proto          = IPPROTO_ESP,
         .init_state     = esp_init_state,
         .destructor     = esp_destroy,
-        .get_max_size   = esp4_get_max_size,
+        .get_mtu        = esp4_get_mtu,
         .input          = esp_input,
         .output         = esp_output
 };