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Diffstat (limited to 'net/ipv4/esp4.c')
-rw-r--r--net/ipv4/esp4.c32
1 files changed, 24 insertions, 8 deletions
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 14ca1f1..e42a905 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));
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