An upcoming patch adds a configurable, per-socket list of TCP options to
populate in the TCP header. This requires tcp_options_write() to know the
socket (to use the options list) and the skb (to provide visibility to the
packet data for options like TCP_MD5SIG).
Signed-off-by: Christoph Paasch <cpaa...@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martin...@linux.intel.com>
---
net/ipv4/tcp_output.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index df50c7dc1a43..e598bf54e3fb 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -444,10 +444,14 @@ struct tcp_out_options {
* At least SACK_PERM as the first option is known to lead to a disaster
* (but it may well be that other scenarios fail similarly).
*/
-static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
+static void tcp_options_write(__be32 *ptr, struct sk_buff *skb, struct sock
*sk,
struct tcp_out_options *opts)
{
u16 options = opts->options; /* mungable copy */
+ struct tcp_sock *tp = NULL;
+
+ if (sk_fullsock(sk))
+ tp = tcp_sk(sk);
if (unlikely(OPTION_MD5 & options)) {
*ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
@@ -1136,7 +1140,7 @@ static int tcp_transmit_skb(struct sock *sk, struct
sk_buff *skb, int clone_it,
*/
th->window = htons(min(tp->rcv_wnd, 65535U));
}
- tcp_options_write((__be32 *)(th + 1), tp, &opts);
+ tcp_options_write((__be32 *)(th + 1), skb, sk, &opts);
#ifdef CONFIG_TCP_MD5SIG
/* Calculate the MD5 hash, as we have all we need now */
if (md5) {
@@ -3248,7 +3252,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk,
struct dst_entry *dst,
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
th->window = htons(min(req->rsk_rcv_wnd, 65535U));
th->doff = (tcp_header_size >> 2);
- tcp_options_write((__be32 *)(th + 1), NULL, &opts);
+ tcp_options_write((__be32 *)(th + 1), skb, req_to_sk(req), &opts);
__TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
#ifdef CONFIG_TCP_MD5SIG
--
2.16.1
