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-rw-r--r--net/ipv4/tcp.c72
1 files changed, 70 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 850825d..c66ac83 100644
--- 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>
@@ -2465,6 +2463,76 @@ 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;
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