[feature] respond to server check alive requests #709
Description
when the ssh server is configured to check clients alive status with:
ClientAliveCountMax 2
ClientAliveInterval 5
the client should reply to the server requests to prevent the server from terminating the session but it does not as you can see in this server log:
Jul 23 11:24:09 localhost sshd[5270]: debug3: send packet: type 81 [SSH_MSG_REQUEST_SUCCESS]
Jul 23 11:24:09 localhost sshd[5270]: debug3: send packet: type 80 [SSH_MSG_GLOBAL_REQUEST]
Jul 23 11:24:14 localhost sshd[5270]: debug3: send packet: type 80 [SSH_MSG_GLOBAL_REQUEST]
Jul 23 11:24:19 localhost sshd[5270]: Timeout, client not responding from user user1 192.168.43.253 port 51236
with putty the server logs:
Jul 23 11:44:20 localhost sshd[5364]: debug3: send packet: type 99 [SSH_MSG_CHANNEL_SUCCESS]
Jul 23 11:44:20 localhost sshd[5360]: debug3: mm_request_receive entering
Jul 23 11:44:20 localhost sshd[5360]: debug3: monitor_read: checking request 124
Jul 23 11:44:25 localhost sshd[5364]: debug2: channel 2: request keepalive@openssh.com confirm 1
Jul 23 11:44:25 localhost sshd[5364]: debug3: send packet: type 98 [SSH_MSG_CHANNEL_REQUEST]
Jul 23 11:44:25 localhost sshd[5364]: debug3: receive packet: type 100 [SSH_MSG_CHANNEL_FAILURE]
Jul 23 11:44:25 localhost sshd[5364]: debug1: Got 100/12 for keepalive
Jul 23 11:44:30 localhost sshd[5364]: debug2: channel 2: request keepalive@openssh.com confirm 1
Jul 23 11:44:30 localhost sshd[5364]: debug3: send packet: type 98 [SSH_MSG_CHANNEL_REQUEST]
Jul 23 11:44:30 localhost sshd[5364]: debug3: receive packet: type 100 [SSH_MSG_CHANNEL_FAILURE]
Jul 23 11:44:30 localhost sshd[5364]: debug1: Got 100/13 for keepalive
PS: does the client respond to tcp_keepalive messages (TCPKeepAlive yes)?