*/
#include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.94 2001/12/28 15:06:00 markus Exp $");
+RCSID("$OpenBSD: clientloop.c,v 1.122 2004/05/22 06:32:12 djm Exp $");
#include "ssh.h"
#include "ssh1.h"
#include "clientloop.h"
#include "authfd.h"
#include "atomicio.h"
-#include "sshtty.h"
+#include "sshpty.h"
#include "misc.h"
/* import options */
/* Flag indicating that stdin should be redirected from /dev/null. */
extern int stdin_null_flag;
+/* Flag indicating that no shell has been requested */
+extern int no_shell_flag;
+
/*
* Name of the host we are connecting to. This is the name given on the
* command line, or the HostName specified for the user-supplied name in a
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;
if (in_non_blocking_mode) {
(void) fcntl(fileno(stdin), F_SETFL, 0);
in_non_blocking_mode = 0;
- fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL);
}
}
{
in_non_blocking_mode = 1;
(void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
- fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
}
/*
}
}
+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).
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);
/*
* 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];
/*
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
/* Flush stdout and stderr buffers. */
if (buffer_len(bout) > 0)
- atomicio(write, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
+ atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
if (buffer_len(berr) > 0)
- atomicio(write, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
+ atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
leave_raw_mode();
}
}
+static void
+process_cmdline(void)
+{
+ void (*handler)(int);
+ char *s, *cmd;
+ u_short fwd_port, fwd_host_port;
+ char buf[1024], sfwd_port[6], sfwd_host_port[6];
+ int delete = 0;
+ int local = 0;
+
+ leave_raw_mode();
+ handler = signal(SIGINT, SIG_IGN);
+ cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
+ if (s == NULL)
+ goto out;
+ while (*s && isspace(*s))
+ s++;
+ if (*s == '-')
+ s++; /* Skip cmdline '-', if any */
+ if (*s == '\0')
+ goto out;
+
+ if (*s == 'h' || *s == 'H' || *s == '?') {
+ logit("Commands:");
+ logit(" -Lport:host:hostport Request local forward");
+ logit(" -Rport:host:hostport Request remote forward");
+ logit(" -KRhostport Cancel remote forward");
+ goto out;
+ }
+
+ if (*s == 'K') {
+ delete = 1;
+ s++;
+ }
+ if (*s != 'L' && *s != 'R') {
+ logit("Invalid command.");
+ goto out;
+ }
+ if (*s == 'L')
+ local = 1;
+ if (local && delete) {
+ logit("Not supported.");
+ goto out;
+ }
+ if ((!local || delete) && !compat20) {
+ logit("Not supported for SSH protocol version 1.");
+ goto out;
+ }
+
+ s++;
+ while (*s && isspace(*s))
+ s++;
+
+ if (delete) {
+ if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
+ logit("Bad forwarding specification.");
+ goto out;
+ }
+ if ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
+ logit("Bad forwarding port(s).");
+ goto out;
+ }
+ channel_request_rforward_cancel(fwd_host_port);
+ } else {
+ if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
+ sfwd_port, buf, sfwd_host_port) != 3 &&
+ sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
+ sfwd_port, buf, sfwd_host_port) != 3) {
+ logit("Bad forwarding specification.");
+ goto out;
+ }
+ if ((fwd_port = a2port(sfwd_port)) == 0 ||
+ (fwd_host_port = a2port(sfwd_host_port)) == 0) {
+ logit("Bad forwarding port(s).");
+ goto out;
+ }
+ if (local) {
+ if (channel_setup_local_fwd_listener(fwd_port, buf,
+ fwd_host_port, options.gateway_ports) < 0) {
+ logit("Port forwarding failed.");
+ goto out;
+ }
+ } else
+ channel_request_remote_forwarding(fwd_port, buf,
+ fwd_host_port);
+ logit("Forwarding port.");
+ }
+
+out:
+ signal(SIGINT, handler);
+ enter_raw_mode();
+ if (cmd)
+ xfree(cmd);
+}
+
/* process the characters one by one */
static int
process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
/* We have been continued. */
continue;
+ case 'B':
+ if (compat20) {
+ snprintf(string, sizeof string,
+ "%cB\r\n", escape_char);
+ buffer_append(berr, string,
+ strlen(string));
+ channel_request_start(session_ident,
+ "break", 0);
+ packet_put_int(1000);
+ packet_send();
+ }
+ continue;
+
case 'R':
if (compat20) {
if (datafellows & SSH_BUG_NOREKEY)
- log("Server does not support re-keying");
+ logit("Server does not support re-keying");
else
need_rekeying = 1;
}
snprintf(string, sizeof string,
"%c?\r\n\
Supported escape sequences:\r\n\
-~. - terminate connection\r\n\
-~R - Request rekey (SSH protocol 2 only)\r\n\
-~^Z - suspend ssh\r\n\
-~# - list forwarded connections\r\n\
-~& - background ssh (when waiting for connections to terminate)\r\n\
-~? - this message\r\n\
-~~ - send the escape character by typing it twice\r\n\
+%c. - terminate connection\r\n\
+%cB - send a BREAK to the remote system\r\n\
+%cC - open a command line\r\n\
+%cR - Request rekey (SSH protocol 2 only)\r\n\
+%c^Z - suspend ssh\r\n\
+%c# - list forwarded connections\r\n\
+%c& - background ssh (when waiting for connections to terminate)\r\n\
+%c? - this message\r\n\
+%c%c - send the escape character by typing it twice\r\n\
(Note that escapes are only recognized immediately after newline.)\r\n",
- escape_char);
+ escape_char, escape_char, escape_char, escape_char,
+ escape_char, escape_char, escape_char, escape_char,
+ escape_char, escape_char, escape_char);
buffer_append(berr, string, strlen(string));
continue;
xfree(s);
continue;
+ case 'C':
+ process_cmdline();
+ continue;
+
default:
if (ch != escape_char) {
buffer_put_char(bin, escape_char);
id, session_ident);
channel_cancel_cleanup(id);
session_closed = 1;
- if (in_raw_mode())
- leave_raw_mode();
+ leave_raw_mode();
}
/*
client_init_dispatch();
- /* Set signal handlers to restore non-blocking mode. */
- signal(SIGINT, signal_handler);
- signal(SIGQUIT, signal_handler);
- signal(SIGTERM, signal_handler);
+ /*
+ * Set signal handlers, (e.g. to restore non-blocking mode)
+ * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
+ */
+ if (signal(SIGINT, SIG_IGN) != SIG_IGN)
+ signal(SIGINT, signal_handler);
+ if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
+ signal(SIGQUIT, signal_handler);
+ if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
+ signal(SIGTERM, signal_handler);
if (have_pty)
signal(SIGWINCH, window_change_handler);
/* Do channel operations unless rekeying in progress. */
if (!rekeying) {
channel_after_select(readset, writeset);
-
- if (need_rekeying) {
- debug("user requests rekeying");
+ if (need_rekeying || packet_need_rekeying()) {
+ debug("need rekeying");
xxx_kex->done = 0;
kex_send_kexinit(xxx_kex);
need_rekeying = 0;
if (!isatty(fileno(stderr)))
unset_nonblock(fileno(stderr));
- if (received_signal) {
- if (in_non_blocking_mode) /* XXX */
- leave_non_blocking();
- fatal("Killed by signal %d.", (int) received_signal);
+ /*
+ * If there was no shell or command requested, there will be no remote
+ * exit status to be returned. In that case, clear error code if the
+ * connection was deliberately terminated at this end.
+ */
+ if (no_shell_flag && received_signal == SIGTERM) {
+ received_signal = 0;
+ exit_status = 0;
}
+ if (received_signal)
+ fatal("Killed by signal %d.", (int) received_signal);
+
/*
* In interactive mode (with pseudo tty) display a message indicating
* that the connection has been closed.
/* Flag that we want to exit. */
quit_pending = 1;
}
+static void
+client_input_agent_open(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c = NULL;
+ int remote_id, sock;
+
+ /* Read the remote channel number from the message. */
+ remote_id = packet_get_int();
+ packet_check_eom();
+
+ /*
+ * Get a connection to the local authentication agent (this may again
+ * get forwarded).
+ */
+ sock = ssh_get_authentication_socket();
+
+ /*
+ * If we could not connect the agent, send an error message back to
+ * the server. This should never happen unless the agent dies,
+ * because authentication forwarding is only enabled if we have an
+ * agent.
+ */
+ if (sock >= 0) {
+ c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
+ -1, 0, 0, 0, "authentication agent connection", 1);
+ c->remote_id = remote_id;
+ c->force_drain = 1;
+ }
+ if (c == NULL) {
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(remote_id);
+ } else {
+ /* Send a confirmation to the remote host. */
+ debug("Forwarding authentication connection.");
+ packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(remote_id);
+ packet_put_int(c->self);
+ }
+ packet_send();
+}
static Channel *
client_request_forwarded_tcpip(const char *request_type, int rchan)
{
- Channel* c = NULL;
+ Channel *c = NULL;
char *listen_address, *originator_address;
int listen_port, originator_port;
int sock;
c = channel_new("forwarded-tcpip",
SSH_CHANNEL_CONNECTING, sock, sock, -1,
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
- xstrdup(originator_address), 1);
- if (c == NULL) {
- error("client_request_forwarded_tcpip: channel_new failed");
- close(sock);
- }
+ originator_address, 1);
xfree(originator_address);
xfree(listen_address);
return c;
}
-static Channel*
+static Channel *
client_request_x11(const char *request_type, int rchan)
{
Channel *c = NULL;
return NULL;
c = channel_new("x11",
SSH_CHANNEL_X11_OPEN, sock, sock, -1,
- CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0,
- xstrdup("x11"), 1);
- if (c == NULL) {
- error("client_request_x11: channel_new failed");
- close(sock);
- }
+ CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
c->force_drain = 1;
return c;
}
-static Channel*
+static Channel *
client_request_agent(const char *request_type, int rchan)
{
Channel *c = NULL;
c = channel_new("authentication agent connection",
SSH_CHANNEL_OPEN, sock, sock, -1,
CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
- xstrdup("authentication agent connection"), 1);
- if (c == NULL) {
- error("client_request_agent: channel_new failed");
- close(sock);
- }
+ "authentication agent connection", 1);
c->force_drain = 1;
return c;
}
{
Channel *c = NULL;
char *ctype;
- u_int len;
int rchan;
- int rmaxpack;
- int rwindow;
+ u_int rmaxpack, rwindow, len;
ctype = packet_get_string(&len);
rchan = packet_get_int();
}
xfree(rtype);
}
+static void
+client_input_global_request(int type, u_int32_t seq, void *ctxt)
+{
+ char *rtype;
+ int want_reply;
+ int success = 0;
+
+ rtype = packet_get_string(NULL);
+ want_reply = packet_get_char();
+ 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);
+ packet_send();
+ packet_write_wait();
+ }
+ xfree(rtype);
+}
static void
client_init_dispatch_20(void)
{
dispatch_init(&dispatch_protocol_error);
+
dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
+ dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
/* rekeying */
dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+
+ /* global request reply messages */
+ dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
+ dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
}
static void
client_init_dispatch_13(void)
dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
- &auth_input_open_request : &deny_input_open);
+ &client_input_agent_open : &deny_input_open);
dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
&x11_input_open : &deny_input_open);
}
else
client_init_dispatch_15();
}
+
+/* client specific fatal cleanup */
+void
+cleanup_exit(int i)
+{
+ leave_raw_mode();
+ leave_non_blocking();
+ _exit(i);
+}