diff options
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 72 |
1 files changed, 70 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 850825dc86e..c66ac83316e 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; |