- markus@cvs.openbsd.org 2003/12/16 15:49:51
[clientloop.c clientloop.h readconf.c readconf.h scp.1 sftp.1 ssh.1]
[ssh.c ssh_config.5]
application layer keep alive (ServerAliveInterval ServerAliveCountMax)
for ssh(1), similar to the sshd(8) option; ok beck@; with help from
jmc and dtucker@
diff --git a/clientloop.c b/clientloop.c
index 67b9dfc..626b29a 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -59,7 +59,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.116 2003/12/09 23:45:32 dtucker Exp $");
+RCSID("$OpenBSD: clientloop.c,v 1.117 2003/12/16 15:49:51 markus Exp $");
#include "ssh.h"
#include "ssh1.h"
@@ -127,6 +127,7 @@
static int connection_out; /* Connection to server (output). */
static int need_rekeying; /* Set to non-zero if rekeying is requested. */
static int session_closed = 0; /* In SSH2: login session closed. */
+static int server_alive_timeouts = 0;
static void client_init_dispatch(void);
int session_ident = -1;
@@ -313,6 +314,24 @@
}
}
+static void
+client_global_request_reply(int type, u_int32_t seq, void *ctxt)
+{
+ server_alive_timeouts = 0;
+ client_global_request_reply_fwd(type, seq, ctxt);
+}
+
+static void
+server_alive_check(void)
+{
+ if (++server_alive_timeouts > options.server_alive_count_max)
+ packet_disconnect("Timeout, server not responding.");
+ packet_start(SSH2_MSG_GLOBAL_REQUEST);
+ packet_put_cstring("keepalive@openssh.com");
+ packet_put_char(1); /* boolean: want reply */
+ packet_send();
+}
+
/*
* Waits until the client can do something (some data becomes available on
* one of the file descriptors).
@@ -322,6 +341,9 @@
client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
int *maxfdp, int *nallocp, int rekeying)
{
+ struct timeval tv, *tvp;
+ int ret;
+
/* Add any selections by the channel mechanism. */
channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
@@ -363,13 +385,18 @@
/*
* Wait for something to happen. This will suspend the process until
* some selected descriptor can be read, written, or has some other
- * event pending. Note: if you want to implement SSH_MSG_IGNORE
- * messages to fool traffic analysis, this might be the place to do
- * it: just have a random timeout for the select, and send a random
- * SSH_MSG_IGNORE packet when the timeout expires.
+ * event pending.
*/
- if (select((*maxfdp)+1, *readsetp, *writesetp, NULL, NULL) < 0) {
+ if (options.server_alive_interval == 0 || !compat20)
+ tvp = NULL;
+ else {
+ tv.tv_sec = options.server_alive_interval;
+ tv.tv_usec = 0;
+ tvp = &tv;
+ }
+ ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
+ if (ret < 0) {
char buf[100];
/*
@@ -386,7 +413,8 @@
snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
buffer_append(&stderr_buffer, buf, strlen(buf));
quit_pending = 1;
- }
+ } else if (ret == 0)
+ server_alive_check();
}
static void
@@ -1365,7 +1393,8 @@
rtype = packet_get_string(NULL);
want_reply = packet_get_char();
- debug("client_input_global_request: rtype %s want_reply %d", rtype, want_reply);
+ debug("client_input_global_request: rtype %s want_reply %d",
+ rtype, want_reply);
if (want_reply) {
packet_start(success ?
SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);