[TCP_IPV4]: Use kmemdup where appropriate

Also use a variable to avoid the longish tp->md5sig_info-> use
in tcp_v4_md5_do_add.

Code diff stats:

[acme@newtoy net-2.6.20]$ codiff /tmp/tcp_ipv4.o.before /tmp/tcp_ipv4.o.after
/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ipv4/tcp_ipv4.c:
  tcp_v4_md5_do_add     |  -62
  tcp_v4_syn_recv_sock  |  -32
  tcp_v4_parse_md5_keys |  -86
 3 functions changed, 180 bytes removed
[acme@newtoy net-2.6.20]$

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

1 files changed, 25 insertions, 24 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 010dff442a11..b7d5522092eb 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -855,15 +855,18 @@ int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
         struct tcp_sock *tp = tcp_sk(sk);
         struct tcp4_md5sig_key *keys;
 
-        key = (struct tcp4_md5sig_key *) tcp_v4_md5_do_lookup(sk, addr);
+        key = (struct tcp4_md5sig_key *)tcp_v4_md5_do_lookup(sk, addr);
         if (key) {
                 /* Pre-existing entry - just update that one. */
-                kfree (key->key);
+                kfree(key->key);
                 key->key = newkey;
                 key->keylen = newkeylen;
         } else {
+                struct tcp_md5sig_info *md5sig;
+
                 if (!tp->md5sig_info) {
-                        tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
+                        tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
+                                                  GFP_ATOMIC);
                         if (!tp->md5sig_info) {
                                 kfree(newkey);
                                 return -ENOMEM;
@@ -873,30 +876,31 @@ int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
                         kfree(newkey);
                         return -ENOMEM;
                 }
-                if (tp->md5sig_info->alloced4 == tp->md5sig_info->entries4) {
-                        keys = kmalloc((sizeof(struct tcp4_md5sig_key) *
-                                       (tp->md5sig_info->entries4 + 1)), GFP_ATOMIC);
+                md5sig = tp->md5sig_info;
+
+                if (md5sig->alloced4 == md5sig->entries4) {
+                        keys = kmalloc((sizeof(*keys) *
+                                        (md5sig->entries4 + 1)), GFP_ATOMIC);
                         if (!keys) {
                                 kfree(newkey);
                                 tcp_free_md5sig_pool();
                                 return -ENOMEM;
                         }
 
-                        if (tp->md5sig_info->entries4)
-                                memcpy(keys, tp->md5sig_info->keys4,
-                                       (sizeof (struct tcp4_md5sig_key) *
-                                        tp->md5sig_info->entries4));
+                        if (md5sig->entries4)
+                                memcpy(keys, md5sig->keys4,
+                                       sizeof(*keys) * md5sig->entries4);
 
                         /* Free old key list, and reference new one */
-                        if (tp->md5sig_info->keys4)
-                                kfree(tp->md5sig_info->keys4);
-                        tp->md5sig_info->keys4 = keys;
-                        tp->md5sig_info->alloced4++;
+                        if (md5sig->keys4)
+                                kfree(md5sig->keys4);
+                        md5sig->keys4 = keys;
+                        md5sig->alloced4++;
                 }
-                tp->md5sig_info->entries4++;
-                tp->md5sig_info->keys4[tp->md5sig_info->entries4 - 1].addr = addr;
-                tp->md5sig_info->keys4[tp->md5sig_info->entries4 - 1].key = newkey;
-                tp->md5sig_info->keys4[tp->md5sig_info->entries4 - 1].keylen = newkeylen;
+                md5sig->entries4++;
+                md5sig->keys4[md5sig->entries4 - 1].addr   = addr;
+                md5sig->keys4[md5sig->entries4 - 1].key    = newkey;
+                md5sig->keys4[md5sig->entries4 - 1].keylen = newkeylen;
         }
         return 0;
 }
@@ -998,10 +1002,9 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
 
         }
 
-        newkey = kmalloc(cmd.tcpm_keylen, GFP_KERNEL);
+        newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
         if (!newkey)
                 return -ENOMEM;
-        memcpy(newkey, cmd.tcpm_key, cmd.tcpm_keylen);
         return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
                                  newkey, cmd.tcpm_keylen);
 }
@@ -1494,12 +1497,10 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                  * memory, then we end up not copying the key
                  * across. Shucks.
                  */
-                char *newkey = kmalloc(key->keylen, GFP_ATOMIC);
-                if (newkey) {
-                        memcpy(newkey, key->key, key->keylen);
+                char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
+                if (newkey != NULL)
                         tcp_v4_md5_do_add(newsk, inet_sk(sk)->daddr,
                                           newkey, key->keylen);
-                }
         }
 #endif