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authorFlorian Westphal <fw@strlen.de>2022-01-29 17:47:00 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2022-02-04 05:39:27 +0100
commitcc4f9d62037ebcb811f4908bba2986c01df1bd50 (patch)
tree1b224fa5e82741128b88f73e8c2986a2411e5bb3 /net
parenta9e8503def0fd4ed89ade1f61c315f904581d439 (diff)
netfilter: conntrack: move synack init code to helper
It seems more readable to use a common helper in the followup fix rather than copypaste or goto. No functional change intended. The function is only called for syn-ack or syn in repy direction in case of simultaneous open. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_conntrack_proto_tcp.c47
1 files changed, 29 insertions, 18 deletions
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index af5115e127cf..88c89e97d8a2 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -446,6 +446,32 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
}
}
+static void tcp_init_sender(struct ip_ct_tcp_state *sender,
+ struct ip_ct_tcp_state *receiver,
+ const struct sk_buff *skb,
+ unsigned int dataoff,
+ const struct tcphdr *tcph,
+ u32 end, u32 win)
+{
+ /* SYN-ACK in reply to a SYN
+ * or SYN from reply direction in simultaneous open.
+ */
+ sender->td_end =
+ sender->td_maxend = end;
+ sender->td_maxwin = (win == 0 ? 1 : win);
+
+ tcp_options(skb, dataoff, tcph, sender);
+ /* RFC 1323:
+ * Both sides must send the Window Scale option
+ * to enable window scaling in either direction.
+ */
+ if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE &&
+ receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE)) {
+ sender->td_scale = 0;
+ receiver->td_scale = 0;
+ }
+}
+
static bool tcp_in_window(struct nf_conn *ct,
enum ip_conntrack_dir dir,
unsigned int index,
@@ -499,24 +525,9 @@ static bool tcp_in_window(struct nf_conn *ct,
* Initialize sender data.
*/
if (tcph->syn) {
- /*
- * SYN-ACK in reply to a SYN
- * or SYN from reply direction in simultaneous open.
- */
- sender->td_end =
- sender->td_maxend = end;
- sender->td_maxwin = (win == 0 ? 1 : win);
-
- tcp_options(skb, dataoff, tcph, sender);
- /*
- * RFC 1323:
- * Both sides must send the Window Scale option
- * to enable window scaling in either direction.
- */
- if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
- && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
- sender->td_scale =
- receiver->td_scale = 0;
+ tcp_init_sender(sender, receiver,
+ skb, dataoff, tcph,
+ end, win);
if (!tcph->ack)
/* Simultaneous open */
return true;