diff options
Diffstat (limited to 'net/ipv4/esp4.c')
| -rw-r--r-- | net/ipv4/esp4.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 14ca1f1c3fb..e42a905180f 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -23,6 +23,8 @@ struct esp_skb_cb { #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) +static u32 esp4_get_mtu(struct xfrm_state *x, int mtu); + /* * Allocate an AEAD request structure with extra space for SG and IV. * @@ -117,25 +119,35 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) int blksize; int clen; int alen; + int plen; + int tfclen; int nfrags; /* skb is pure payload to encrypt */ err = -ENOMEM; - /* Round to block size */ - clen = skb->len; - esp = x->data; aead = esp->aead; alen = crypto_aead_authsize(aead); + tfclen = 0; + if (x->tfcpad) { + struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); + u32 padto; + + padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); + if (skb->len < padto) + tfclen = padto - skb->len; + } blksize = ALIGN(crypto_aead_blocksize(aead), 4); - clen = ALIGN(clen + 2, blksize); + clen = ALIGN(skb->len + 2 + tfclen, blksize); if (esp->padlen) clen = ALIGN(clen, esp->padlen); + plen = clen - skb->len - tfclen; - if ((err = skb_cow_data(skb, clen - skb->len + alen, &trailer)) < 0) + err = skb_cow_data(skb, tfclen + plen + alen, &trailer); + if (err < 0) goto error; nfrags = err; @@ -150,13 +162,17 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) /* Fill padding... */ tail = skb_tail_pointer(trailer); + if (tfclen) { + memset(tail, 0, tfclen); + tail += tfclen; + } do { int i; - for (i=0; i<clen-skb->len - 2; i++) + for (i = 0; i < plen - 2; i++) tail[i] = i + 1; } while (0); - tail[clen - skb->len - 2] = (clen - skb->len) - 2; - tail[clen - skb->len - 1] = *skb_mac_header(skb); + tail[plen - 2] = plen - 2; + tail[plen - 1] = *skb_mac_header(skb); pskb_put(skb, trailer, clen - skb->len + alen); skb_push(skb, -skb_network_offset(skb)); |