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authorDavid S. Miller <davem@davemloft.net>2008-06-11 22:33:59 -0700
committerDavid S. Miller <davem@davemloft.net>2008-06-11 22:33:59 -0700
commite6e30add6bd8115af108de2a13ec82d997a55777 (patch)
tree558b4d1c3ac369805aa9c57abca710bdf52aff75 /net/ipv4/tcp.c
parentd4c3c0753594adaafbcb77a086f013f1d847b3f0 (diff)
parent9501f9722922f2e80e1f9dc6682311d65c2b5690 (diff)
Merge branch 'net-next-2.6-misc-20080612a' of git://git.linux-ipv6.org/gitroot/yoshfuji/linux-2.6-next
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ad66b09e0bcd..6d30ca559c64 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2457,6 +2457,76 @@ static unsigned long tcp_md5sig_users;
static struct tcp_md5sig_pool **tcp_md5sig_pool;
static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
+int tcp_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
+ int bplen,
+ struct tcphdr *th, unsigned int tcplen,
+ struct tcp_md5sig_pool *hp)
+{
+ struct scatterlist sg[4];
+ __u16 data_len;
+ int block = 0;
+ __sum16 cksum;
+ struct hash_desc *desc = &hp->md5_desc;
+ int err;
+ unsigned int nbytes = 0;
+
+ sg_init_table(sg, 4);
+
+ /* 1. The TCP pseudo-header */
+ sg_set_buf(&sg[block++], &hp->md5_blk, bplen);
+ nbytes += bplen;
+
+ /* 2. The TCP header, excluding options, and assuming a
+ * checksum of zero
+ */
+ cksum = th->check;
+ th->check = 0;
+ sg_set_buf(&sg[block++], th, sizeof(*th));
+ nbytes += sizeof(*th);
+
+ /* 3. The 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. an independently-specified key or password, known to both
+ * TCPs and presumably connection-specific
+ */
+ sg_set_buf(&sg[block++], key->key, key->keylen);
+ nbytes += key->keylen;
+
+ sg_mark_end(&sg[block - 1]);
+
+ /* Now store the hash into the packet */
+ err = crypto_hash_init(desc);
+ if (err) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "%s(): hash_init failed\n", __func__);
+ return -1;
+ }
+ err = crypto_hash_update(desc, sg, nbytes);
+ if (err) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "%s(): hash_update failed\n", __func__);
+ return -1;
+ }
+ err = crypto_hash_final(desc, md5_hash);
+ if (err) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "%s(): hash_final failed\n", __func__);
+ return -1;
+ }
+
+ /* Reset header */
+ th->check = cksum;
+
+ return 0;
+}
+EXPORT_SYMBOL(tcp_calc_md5_hash);
+
static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
{
int cpu;