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>

1 files changed, 20 insertions, 0 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 */