3 files changed, 79 insertions, 96 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ab66683b8043..6efbae0e5512 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2459,6 +2459,76 @@ 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;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f25445d21bdf..e331cdbd0953 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1006,15 +1006,9 @@ static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
                                    struct tcphdr *th,
                                    unsigned int tcplen)
 {
-        struct scatterlist sg[4];
-        __u16 data_len;
-        int block = 0;
-        __sum16 old_checksum;
         struct tcp_md5sig_pool *hp;
         struct tcp4_pseudohdr *bp;
-        struct hash_desc *desc;
         int err;
-        unsigned int nbytes = 0;
 
         /*
          * Okay, so RFC2385 is turned on for this connection,
@@ -1026,10 +1020,9 @@ static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
                 goto clear_hash_noput;
 
         bp = &hp->md5_blk.ip4;
-        desc = &hp->md5_desc;
 
         /*
-         * 1. the TCP pseudo-header (in the order: source IP address,
+         * The TCP pseudo-header (in the order: source IP address,
          * destination IP address, zero-padded protocol number, and
          * segment length)
          */
@@ -1039,50 +1032,13 @@ static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
         bp->protocol = IPPROTO_TCP;
         bp->len = htons(tcplen);
 
-        sg_init_table(sg, 4);
-
-        sg_set_buf(&sg[block++], bp, sizeof(*bp));
-        nbytes += sizeof(*bp);
-
-        /* 2. the TCP header, excluding options, and assuming a
-         * checksum of zero/
-         */
-        old_checksum = th->check;
-        th->check = 0;
-        sg_set_buf(&sg[block++], th, sizeof(struct tcphdr));
-        nbytes += sizeof(struct tcphdr);
-
-        /* 3. the TCP segment data (if any) */
-        data_len = tcplen - (th->doff << 2);
-        if (data_len > 0) {
-                unsigned char *data = (unsigned char *)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)
-                goto clear_hash;
-        err = crypto_hash_update(desc, sg, nbytes);
-        if (err)
-                goto clear_hash;
-        err = crypto_hash_final(desc, md5_hash);
+        err = tcp_calc_md5_hash(md5_hash, key, sizeof(*bp),
+                                th, tcplen, hp);
         if (err)
                 goto clear_hash;
 
-        /* Reset header, and free up the crypto */
+        /* Free up the crypto pool */
         tcp_put_md5sig_pool();
-        th->check = old_checksum;
-
 out:
         return 0;
 clear_hash:
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 334d21c23da9..0ae0311082fb 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: