tcp md5sig: Share most of hash calcucaltion bits between IPv4 and IPv6.

We can share most part of the hash calculation code because
the only difference between IPv4 and IPv6 is their pseudo headers.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 5 insertions, 48 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 334d21c23da..0ae0311082f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -738,23 +738,17 @@ static int tcp_v6_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 				   struct in6_addr *daddr,
 				   struct tcphdr *th, unsigned int tcplen)
 {
-	struct scatterlist sg[4];
-	__u16 data_len;
-	int block = 0;
-	__sum16 cksum;
 	struct tcp_md5sig_pool *hp;
 	struct tcp6_pseudohdr *bp;
-	struct hash_desc *desc;
 	int err;
-	unsigned int nbytes = 0;
 
 	hp = tcp_get_md5sig_pool();
 	if (!hp) {
 		printk(KERN_WARNING "%s(): hash pool not found...\n", __func__);
 		goto clear_hash_noput;
 	}
+
 	bp = &hp->md5_blk.ip6;
-	desc = &hp->md5_desc;
 
 	/* 1. TCP pseudo-header (RFC2460) */
 	ipv6_addr_copy(&bp->saddr, saddr);
@@ -762,51 +756,14 @@ static int tcp_v6_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
 	bp->len = htonl(tcplen);
 	bp->protocol = htonl(IPPROTO_TCP);
 
-	sg_init_table(sg, 4);
-
-	sg_set_buf(&sg[block++], bp, sizeof(*bp));
-	nbytes += sizeof(*bp);
-
-	/* 2. TCP header, excluding options */
-	cksum = th->check;
-	th->check = 0;
-	sg_set_buf(&sg[block++], th, sizeof(*th));
-	nbytes += sizeof(*th);
-
-	/* 3. TCP segment data (if any) */
-	data_len = tcplen - (th->doff << 2);
-	if (data_len > 0) {
-		u8 *data = (u8 *)th + (th->doff << 2);
-		sg_set_buf(&sg[block++], data, data_len);
-		nbytes += data_len;
-	}
-
-	/* 4. shared key */
-	sg_set_buf(&sg[block++], key->key, key->keylen);
-	nbytes += key->keylen;
-
-	sg_mark_end(&sg[block - 1]);
+	err = tcp_calc_md5_hash(md5_hash, key, sizeof(*bp),
+				th, tcplen, hp);
 
-	/* Now store the hash into the packet */
-	err = crypto_hash_init(desc);
-	if (err) {
-		printk(KERN_WARNING "%s(): hash_init failed\n", __func__);
-		goto clear_hash;
-	}
-	err = crypto_hash_update(desc, sg, nbytes);
-	if (err) {
-		printk(KERN_WARNING "%s(): hash_update failed\n", __func__);
-		goto clear_hash;
-	}
-	err = crypto_hash_final(desc, md5_hash);
-	if (err) {
-		printk(KERN_WARNING "%s(): hash_final failed\n", __func__);
+	if (err)
 		goto clear_hash;
-	}
 
-	/* Reset header, and free up the crypto */
+	/* Free up the crypto pool */
 	tcp_put_md5sig_pool();
-	th->check = cksum;
 out:
 	return 0;
 clear_hash: