]> andersk Git - openssh.git/blobdiff - clientloop.c
- (tim) [regress/README.regress] Document ssh-rand-helper issue. ok bal
[openssh.git] / clientloop.c
index cd2eab77a9c057d7ac5012636f435f73089865be..626b29a5a24fd1a4af6a2b736aa2f907a5084cae 100644 (file)
@@ -59,7 +59,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.102 2002/06/24 14:33:27 markus Exp $");
+RCSID("$OpenBSD: clientloop.c,v 1.117 2003/12/16 15:49:51 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -89,6 +89,9 @@ extern Options 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
@@ -124,6 +127,7 @@ static int connection_in;   /* Connection to server (input). */
 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;
@@ -139,7 +143,6 @@ leave_non_blocking(void)
        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);
        }
 }
 
@@ -150,7 +153,6 @@ enter_non_blocking(void)
 {
        in_non_blocking_mode = 1;
        (void) fcntl(fileno(stdin), F_SETFL, O_NONBLOCK);
-       fatal_add_cleanup((void (*) (void *)) leave_non_blocking, NULL);
 }
 
 /*
@@ -312,6 +314,24 @@ client_check_window_change(void)
        }
 }
 
+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).
@@ -321,6 +341,9 @@ static void
 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);
 
@@ -362,13 +385,18 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
        /*
         * 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];
 
                /*
@@ -385,7 +413,8 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
                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
@@ -395,9 +424,9 @@ client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 
        /* 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();
 
@@ -490,13 +519,13 @@ process_cmdline(void)
        if (*s == 0)
                goto out;
        if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) {
-               log("Invalid command.");
+               logit("Invalid command.");
                goto out;
        }
        if (s[1] == 'L')
                local = 1;
        if (!local && !compat20) {
-               log("Not supported for SSH protocol version 1.");
+               logit("Not supported for SSH protocol version 1.");
                goto out;
        }
        s += 2;
@@ -507,24 +536,24 @@ process_cmdline(void)
            sfwd_port, buf, sfwd_host_port) != 3 &&
            sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
            sfwd_port, buf, sfwd_host_port) != 3) {
-               log("Bad forwarding specification.");
+               logit("Bad forwarding specification.");
                goto out;
        }
        if ((fwd_port = a2port(sfwd_port)) == 0 ||
            (fwd_host_port = a2port(sfwd_host_port)) == 0) {
-               log("Bad forwarding port(s).");
+               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) {
-                       log("Port forwarding failed.");
+                       logit("Port forwarding failed.");
                        goto out;
                }
        } else
                channel_request_remote_forwarding(fwd_port, buf,
                    fwd_host_port);
-       log("Forwarding port.");
+       logit("Forwarding port.");
 out:
        signal(SIGINT, handler);
        enter_raw_mode();
@@ -574,10 +603,23 @@ 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;
                                }
@@ -635,16 +677,19 @@ process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
                                snprintf(string, sizeof string,
 "%c?\r\n\
 Supported escape sequences:\r\n\
-~.  - terminate connection\r\n\
-~C  - open a command line\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;
 
@@ -828,8 +873,7 @@ client_channel_closed(int id, void *arg)
                    id, session_ident);
        channel_cancel_cleanup(id);
        session_closed = 1;
-       if (in_raw_mode())
-               leave_raw_mode();
+       leave_raw_mode();
 }
 
 /*
@@ -886,10 +930,16 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 
        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);
 
@@ -960,9 +1010,8 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
                /* 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;
@@ -1013,12 +1062,19 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
        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.
@@ -1110,11 +1166,51 @@ client_input_exit_status(int type, u_int32_t seq, void *ctxt)
        /* 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)
 {
-       Channelc = NULL;
+       Channel *c = NULL;
        char *listen_address, *originator_address;
        int listen_port, originator_port;
        int sock;
@@ -1138,13 +1234,13 @@ client_request_forwarded_tcpip(const char *request_type, int rchan)
        c = channel_new("forwarded-tcpip",
            SSH_CHANNEL_CONNECTING, sock, sock, -1,
            CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
-           xstrdup(originator_address), 1);
+           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;
@@ -1174,13 +1270,12 @@ client_request_x11(const char *request_type, int rchan)
                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);
+           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;
@@ -1197,7 +1292,7 @@ client_request_agent(const char *request_type, int rchan)
        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);
+           "authentication agent connection", 1);
        c->force_drain = 1;
        return c;
 }
@@ -1298,7 +1393,8 @@ client_input_global_request(int type, u_int32_t seq, void *ctxt)
 
        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);
@@ -1346,7 +1442,7 @@ 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);
 }
@@ -1367,3 +1463,12 @@ client_init_dispatch(void)
        else
                client_init_dispatch_15();
 }
+
+/* client specific fatal cleanup */
+void
+cleanup_exit(int i)
+{
+       leave_raw_mode();
+       leave_non_blocking();
+       _exit(i);
+}
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