Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

[safe/jmp/linux-2.6] / net / ipv4 / tcp.c

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index fc54a48..cf0850c 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -5,8 +5,6 @@
  *
  *             Implementation of the Transmission Control Protocol(TCP).
  *
- * Version:    $Id: tcp.c,v 1.216 2002/02/01 22:01:04 davem Exp $
- *
  * Authors:    Ross Biro
  *             Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  *             Mark Evans, <evansmp@uhura.aston.ac.uk>
@@ -2463,6 +2461,76 @@ 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;