ipv4: share tcp_v4_save_options() with cookie_v4_check()

cookie_v4_check() allocates ip_options_rcu in the same way
with tcp_v4_save_options(), we can just make it a helper function.

Cc: Krzysztof Kolasa <kkolasa@winsoft.pl>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 21 insertions, 29 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 74efeda994b3..869637a7caf7 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1666,4 +1666,24 @@ int tcpv4_offload_init(void);
 void tcp_v4_init(void);
 void tcp_init(void);
 
+/*
+ * Save and compile IPv4 options, return a pointer to it
+ */
+static inline struct ip_options_rcu *tcp_v4_save_options(struct sk_buff *skb)
+{
+        const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt;
+        struct ip_options_rcu *dopt = NULL;
+
+        if (opt && opt->optlen) {
+                int opt_size = sizeof(*dopt) + opt->optlen;
+
+                dopt = kmalloc(opt_size, GFP_ATOMIC);
+                if (dopt && __ip_options_echo(&dopt->opt, skb, opt)) {
+                        kfree(dopt);
+                        dopt = NULL;
+                }
+        }
+        return dopt;
+}
+
 #endif  /* _TCP_H */
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 7e7401cdb9d7..c68d0a1a468e 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -317,15 +317,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
         /* We throwed the options of the initial SYN away, so we hope
          * the ACK carries the same options again (see RFC1122 4.2.3.8)
          */
-        if (opt && opt->optlen) {
-                int opt_size = sizeof(struct ip_options_rcu) + opt->optlen;
-
-                ireq->opt = kmalloc(opt_size, GFP_ATOMIC);
-                if (ireq->opt != NULL && __ip_options_echo(&ireq->opt->opt, skb, opt)) {
-                        kfree(ireq->opt);
-                        ireq->opt = NULL;
-                }
-        }
+        ireq->opt = tcp_v4_save_options(skb);
 
         if (security_inet_conn_request(sk, skb, req)) {
                 reqsk_free(req);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 552e87e3c269..6a2a7d659a7a 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -880,26 +880,6 @@ bool tcp_syn_flood_action(struct sock *sk,
 }
 EXPORT_SYMBOL(tcp_syn_flood_action);
 
-/*
- * Save and compile IPv4 options into the request_sock if needed.
- */
-static struct ip_options_rcu *tcp_v4_save_options(struct sk_buff *skb)
-{
-        const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt;
-        struct ip_options_rcu *dopt = NULL;
-
-        if (opt && opt->optlen) {
-                int opt_size = sizeof(*dopt) + opt->optlen;
-
-                dopt = kmalloc(opt_size, GFP_ATOMIC);
-                if (dopt && __ip_options_echo(&dopt->opt, skb, opt)) {
-                        kfree(dopt);
-                        dopt = NULL;
-                }
-        }
-        return dopt;
-}
-
 #ifdef CONFIG_TCP_MD5SIG
 /*
  * RFC2385 MD5 checksumming requires a mapping of