kcm: Add receive message timeout

This patch adds receive timeout for message assembly on the attached TCP
sockets. The timeout is set when a new messages is started and the whole
message has not been received by TCP (not in the receive queue). If the
completely message is subsequently received the timer is cancelled, if the
timer expires the RX side is aborted.

The timeout value is taken from the socket timeout (SO_RCVTIMEO) that is
set on a TCP socket (i.e. set by get sockopt before attaching a TCP socket
to KCM.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/net/kcm.h b/include/net/kcm.h
index d892956ff552..95c425ca97b6 100644
--- a/include/net/kcm.h
+++ b/include/net/kcm.h
@@ -29,6 +29,7 @@ struct kcm_psock_stats {
         unsigned int rx_mem_fail;
         unsigned int rx_need_more_hdr;
         unsigned int rx_msg_too_big;
+        unsigned int rx_msg_timeouts;
         unsigned int rx_bad_hdr_len;
         unsigned long long reserved;
         unsigned long long unreserved;
@@ -130,6 +131,7 @@ struct kcm_psock {
         struct kcm_sock *rx_kcm;
         unsigned long long saved_rx_bytes;
         unsigned long long saved_rx_msgs;
+        struct timer_list rx_msg_timer;
         unsigned int rx_need_bytes;
 
         /* Transmit */
@@ -194,6 +196,7 @@ static inline void aggregate_psock_stats(struct kcm_psock_stats *stats,
         SAVE_PSOCK_STATS(rx_mem_fail);
         SAVE_PSOCK_STATS(rx_need_more_hdr);
         SAVE_PSOCK_STATS(rx_msg_too_big);
+        SAVE_PSOCK_STATS(rx_msg_timeouts);
         SAVE_PSOCK_STATS(rx_bad_hdr_len);
         SAVE_PSOCK_STATS(tx_msgs);
         SAVE_PSOCK_STATS(tx_bytes);