X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/fbe90f7b3589b3fb14a51ca06acddfd0f756ce5c..34f2baf0f5d9dad08aaed92f16ee660b9c150d65:/clientloop.c diff --git a/clientloop.c b/clientloop.c index d7618973..def4d8a7 100644 --- a/clientloop.c +++ b/clientloop.c @@ -35,7 +35,7 @@ * * * SSH2 support added by Markus Friedl. - * Copyright (c) 1999,2000 Markus Friedl. All rights reserved. + * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -59,7 +59,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: clientloop.c,v 1.66 2001/04/29 19:16:52 markus Exp $"); +RCSID("$OpenBSD: clientloop.c,v 1.129 2004/07/11 17:48:47 deraadt Exp $"); #include "ssh.h" #include "ssh1.h" @@ -79,8 +79,11 @@ RCSID("$OpenBSD: clientloop.c,v 1.66 2001/04/29 19:16:52 markus Exp $"); #include "clientloop.h" #include "authfd.h" #include "atomicio.h" -#include "sshtty.h" +#include "sshpty.h" #include "misc.h" +#include "monitor_fdpass.h" +#include "match.h" +#include "msg.h" /* import options */ extern Options options; @@ -88,6 +91,12 @@ 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; + +/* Control socket */ +extern int control_fd; + /* * 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 @@ -101,7 +110,8 @@ extern char *host; * window size to be sent to the server a little later. This is volatile * because this is updated in a signal handler. */ -static volatile int received_window_change_signal = 0; +static volatile sig_atomic_t received_window_change_signal = 0; +static volatile sig_atomic_t received_signal = 0; /* Flag indicating whether the user\'s terminal is in non-blocking mode. */ static int in_non_blocking_mode = 0; @@ -122,33 +132,43 @@ 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; -void client_init_dispatch(void); +static void client_init_dispatch(void); int session_ident = -1; +struct confirm_ctx { + int want_tty; + int want_subsys; + Buffer cmd; + char *term; + struct termios tio; + char **env; +}; + /*XXX*/ extern Kex *xxx_kex; +void ssh_process_session2_setup(int, int, int, Buffer *); + /* Restores stdin to blocking mode. */ -void +static void leave_non_blocking(void) { if (in_non_blocking_mode) { - (void) fcntl(fileno(stdin), F_SETFL, 0); + unset_nonblock(fileno(stdin)); in_non_blocking_mode = 0; - fatal_remove_cleanup((void (*) (void *)) leave_non_blocking, NULL); } } /* Puts stdin terminal in non-blocking mode. */ -void +static void 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); + set_nonblock(fileno(stdin)); } /* @@ -156,7 +176,7 @@ enter_non_blocking(void) * flag indicating that the window has changed. */ -void +static void window_change_handler(int sig) { received_window_change_signal = 1; @@ -168,16 +188,11 @@ window_change_handler(int sig) * signals must be trapped to restore terminal modes. */ -void +static void signal_handler(int sig) { - if (in_raw_mode()) - leave_raw_mode(); - if (in_non_blocking_mode) - leave_non_blocking(); - channel_stop_listening(); - packet_close(); - fatal("Killed by signal %d.", sig); + received_signal = sig; + quit_pending = 1; } /* @@ -185,7 +200,7 @@ signal_handler(int sig) * available resolution. */ -double +static double get_current_time(void) { struct timeval tv; @@ -199,7 +214,7 @@ get_current_time(void) * not appear to wake up when redirecting from /dev/null. */ -void +static void client_check_initial_eof_on_stdin(void) { int len; @@ -251,14 +266,14 @@ client_check_initial_eof_on_stdin(void) * connection. */ -void +static void client_make_packets_from_stdin_data(void) { u_int len; /* Send buffered stdin data to the server. */ while (buffer_len(&stdin_buffer) > 0 && - packet_not_very_much_data_to_write()) { + packet_not_very_much_data_to_write()) { len = buffer_len(&stdin_buffer); /* Keep the packets at reasonable size. */ if (len > packet_get_maxsize()) @@ -283,7 +298,7 @@ client_make_packets_from_stdin_data(void) * appropriate. */ -void +static void client_check_window_change(void) { struct winsize ws; @@ -293,19 +308,13 @@ client_check_window_change(void) /** XXX race */ received_window_change_signal = 0; - if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) - return; - debug2("client_check_window_change: changed"); if (compat20) { - channel_request_start(session_ident, "window-change", 0); - packet_put_int(ws.ws_col); - packet_put_int(ws.ws_row); - packet_put_int(ws.ws_xpixel); - packet_put_int(ws.ws_ypixel); - packet_send(); + channel_send_window_changes(); } else { + if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) + return; packet_start(SSH_CMSG_WINDOW_SIZE); packet_put_int(ws.ws_row); packet_put_int(ws.ws_col); @@ -315,17 +324,37 @@ 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). */ - -void +static void client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, - int *maxfdp, int rekeying) + 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, rekeying); + channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying); if (!compat20) { /* Read from the connection, unless our buffers are full. */ @@ -346,23 +375,40 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, if (buffer_len(&stderr_buffer) > 0) FD_SET(fileno(stderr), *writesetp); } else { - FD_SET(connection_in, *readsetp); + /* channel_prepare_select could have closed the last channel */ + if (session_closed && !channel_still_open() && + !packet_have_data_to_write()) { + /* clear mask since we did not call select() */ + memset(*readsetp, 0, *nallocp); + memset(*writesetp, 0, *nallocp); + return; + } else { + FD_SET(connection_in, *readsetp); + } } /* Select server connection if have data to write to the server. */ if (packet_have_data_to_write()) FD_SET(connection_out, *writesetp); + if (control_fd != -1) + FD_SET(control_fd, *readsetp); + /* * 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]; /* @@ -370,8 +416,8 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, * We have to return, because the mainloop checks for the flags * set by the signal handlers. */ - memset(*readsetp, 0, *maxfdp); - memset(*writesetp, 0, *maxfdp); + memset(*readsetp, 0, *nallocp); + memset(*writesetp, 0, *nallocp); if (errno == EINTR) return; @@ -379,19 +425,20 @@ 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(); } -void +static void client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) { struct winsize oldws, newws; /* 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(); @@ -412,9 +459,9 @@ client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) /* Check if the window size has changed. */ if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 && (oldws.ws_row != newws.ws_row || - oldws.ws_col != newws.ws_col || - oldws.ws_xpixel != newws.ws_xpixel || - oldws.ws_ypixel != newws.ws_ypixel)) + oldws.ws_col != newws.ws_col || + oldws.ws_xpixel != newws.ws_xpixel || + oldws.ws_ypixel != newws.ws_ypixel)) received_window_change_signal = 1; /* OK, we have been continued by the user. Reinitialize buffers. */ @@ -425,7 +472,7 @@ client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr) enter_raw_mode(); } -void +static void client_process_net_input(fd_set * readset) { int len; @@ -465,8 +512,319 @@ client_process_net_input(fd_set * readset) } } +static void +client_subsystem_reply(int type, u_int32_t seq, void *ctxt) +{ + int id; + Channel *c; + + id = packet_get_int(); + packet_check_eom(); + + if ((c = channel_lookup(id)) == NULL) { + error("%s: no channel for id %d", __func__, id); + return; + } + + if (type == SSH2_MSG_CHANNEL_SUCCESS) + debug2("Request suceeded on channel %d", id); + else if (type == SSH2_MSG_CHANNEL_FAILURE) { + error("Request failed on channel %d", id); + channel_free(c); + } +} + +static void +client_extra_session2_setup(int id, void *arg) +{ + struct confirm_ctx *cctx = arg; + Channel *c; + int i; + + if (cctx == NULL) + fatal("%s: cctx == NULL", __func__); + if ((c = channel_lookup(id)) == NULL) + fatal("%s: no channel for id %d", __func__, id); + + client_session2_setup(id, cctx->want_tty, cctx->want_subsys, + cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env, + client_subsystem_reply); + + c->confirm_ctx = NULL; + buffer_free(&cctx->cmd); + xfree(cctx->term); + if (cctx->env != NULL) { + for (i = 0; cctx->env[i] != NULL; i++) + xfree(cctx->env[i]); + xfree(cctx->env); + } + xfree(cctx); +} + +static void +client_process_control(fd_set * readset) +{ + Buffer m; + Channel *c; + int client_fd, new_fd[3], ver, i, allowed; + socklen_t addrlen; + struct sockaddr_storage addr; + struct confirm_ctx *cctx; + char *cmd; + u_int len, env_len; + uid_t euid; + gid_t egid; + + /* + * Accept connection on control socket + */ + if (control_fd == -1 || !FD_ISSET(control_fd, readset)) + return; + + memset(&addr, 0, sizeof(addr)); + addrlen = sizeof(addr); + if ((client_fd = accept(control_fd, + (struct sockaddr*)&addr, &addrlen)) == -1) { + error("%s accept: %s", __func__, strerror(errno)); + return; + } + + if (getpeereid(client_fd, &euid, &egid) < 0) { + error("%s getpeereid failed: %s", __func__, strerror(errno)); + close(client_fd); + return; + } + if ((euid != 0) && (getuid() != euid)) { + error("control mode uid mismatch: peer euid %u != uid %u", + (u_int) euid, (u_int) getuid()); + close(client_fd); + return; + } + + allowed = 1; + if (options.control_master == 2) { + char *p, prompt[1024]; + + allowed = 0; + snprintf(prompt, sizeof(prompt), + "Allow shared connection to %s? ", host); + p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF); + if (p != NULL) { + /* + * Accept empty responses and responses consisting + * of the word "yes" as affirmative. + */ + if (*p == '\0' || *p == '\n' || + strcasecmp(p, "yes") == 0) + allowed = 1; + xfree(p); + } + } + + unset_nonblock(client_fd); + + buffer_init(&m); + + buffer_put_int(&m, allowed); + buffer_put_int(&m, getpid()); + if (ssh_msg_send(client_fd, /* version */0, &m) == -1) { + error("%s: client msg_send failed", __func__); + close(client_fd); + buffer_free(&m); + return; + } + buffer_clear(&m); + + if (!allowed) { + error("Refused control connection"); + close(client_fd); + buffer_free(&m); + return; + } + + if (ssh_msg_recv(client_fd, &m) == -1) { + error("%s: client msg_recv failed", __func__); + close(client_fd); + buffer_free(&m); + return; + } + + if ((ver = buffer_get_char(&m)) != 0) { + error("%s: wrong client version %d", __func__, ver); + buffer_free(&m); + close(client_fd); + return; + } + + cctx = xmalloc(sizeof(*cctx)); + memset(cctx, 0, sizeof(*cctx)); + + cctx->want_tty = buffer_get_int(&m); + cctx->want_subsys = buffer_get_int(&m); + cctx->term = buffer_get_string(&m, &len); + + cmd = buffer_get_string(&m, &len); + buffer_init(&cctx->cmd); + buffer_append(&cctx->cmd, cmd, strlen(cmd)); + + env_len = buffer_get_int(&m); + env_len = MIN(env_len, 4096); + debug3("%s: receiving %d env vars", __func__, env_len); + if (env_len != 0) { + cctx->env = xmalloc(sizeof(*cctx->env) * (env_len + 1)); + for (i = 0; i < env_len; i++) + cctx->env[i] = buffer_get_string(&m, &len); + cctx->env[i] = NULL; + } + + debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__, + cctx->want_tty, cctx->want_subsys, cmd); + + /* Gather fds from client */ + new_fd[0] = mm_receive_fd(client_fd); + new_fd[1] = mm_receive_fd(client_fd); + new_fd[2] = mm_receive_fd(client_fd); + + debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__, + new_fd[0], new_fd[1], new_fd[2]); + + /* Try to pick up ttymodes from client before it goes raw */ + if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1) + error("%s: tcgetattr: %s", __func__, strerror(errno)); + + buffer_clear(&m); + if (ssh_msg_send(client_fd, /* version */0, &m) == -1) { + error("%s: client msg_send failed", __func__); + close(client_fd); + close(new_fd[0]); + close(new_fd[1]); + close(new_fd[2]); + buffer_free(&m); + return; + } + buffer_free(&m); + + /* enable nonblocking unless tty */ + if (!isatty(new_fd[0])) + set_nonblock(new_fd[0]); + if (!isatty(new_fd[1])) + set_nonblock(new_fd[1]); + if (!isatty(new_fd[2])) + set_nonblock(new_fd[2]); + + set_nonblock(client_fd); + + c = channel_new("session", SSH_CHANNEL_OPENING, + new_fd[0], new_fd[1], new_fd[2], + CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT, + CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0); + + /* XXX */ + c->ctl_fd = client_fd; + + debug3("%s: channel_new: %d", __func__, c->self); + + channel_send_open(c->self); + channel_register_confirm(c->self, client_extra_session2_setup, cctx); +} + +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 */ -int +static int process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len) { char string[1024]; @@ -507,46 +865,42 @@ 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; } continue; case '&': - /* XXX does not work yet with proto 2 */ - if (compat20) - continue; /* * Detach the program (continue to serve connections, * but put in background and no more new connections). */ - if (!stdin_eof) { - /* - * Sending SSH_CMSG_EOF alone does not always appear - * to be enough. So we try to send an EOF character - * first. - */ - packet_start(SSH_CMSG_STDIN_DATA); - packet_put_string("\004", 1); - packet_send(); - /* Close stdin. */ - stdin_eof = 1; - if (buffer_len(bin) == 0) { - packet_start(SSH_CMSG_EOF); - packet_send(); - } - } /* Restore tty modes. */ leave_raw_mode(); /* Stop listening for new connections. */ channel_stop_listening(); - printf("%c& [backgrounded]\n", escape_char); + snprintf(string, sizeof string, + "%c& [backgrounded]\n", escape_char); + buffer_append(berr, string, strlen(string)); /* Fork into background. */ pid = fork(); @@ -559,21 +913,45 @@ process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len) exit(0); } /* The child continues serving connections. */ - continue; /*XXX ? */ + if (compat20) { + buffer_append(bin, "\004", 1); + /* fake EOF on stdin */ + return -1; + } else if (!stdin_eof) { + /* + * Sending SSH_CMSG_EOF alone does not always appear + * to be enough. So we try to send an EOF character + * first. + */ + packet_start(SSH_CMSG_STDIN_DATA); + packet_put_string("\004", 1); + packet_send(); + /* Close stdin. */ + stdin_eof = 1; + if (buffer_len(bin) == 0) { + packet_start(SSH_CMSG_EOF); + packet_send(); + } + } + continue; case '?': 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; @@ -585,6 +963,10 @@ Supported escape sequences:\r\n\ xfree(s); continue; + case 'C': + process_cmdline(); + continue; + default: if (ch != escape_char) { buffer_put_char(bin, escape_char); @@ -616,7 +998,7 @@ Supported escape sequences:\r\n\ return bytes; } -void +static void client_process_input(fd_set * readset) { int len; @@ -651,7 +1033,7 @@ client_process_input(fd_set * readset) packet_start(SSH_CMSG_EOF); packet_send(); } - } else if (escape_char == -1) { + } else if (escape_char == SSH_ESCAPECHAR_NONE) { /* * Normal successful read, and no escape character. * Just append the data to buffer. @@ -669,7 +1051,7 @@ client_process_input(fd_set * readset) } } -void +static void client_process_output(fd_set * writeset) { int len; @@ -730,7 +1112,7 @@ client_process_output(fd_set * writeset) * preparatory phase. */ -void +static void client_process_buffered_input_packets(void) { dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL); @@ -738,29 +1120,26 @@ client_process_buffered_input_packets(void) /* scan buf[] for '~' before sending data to the peer */ -int +static int simple_escape_filter(Channel *c, char *buf, int len) { /* XXX we assume c->extended is writeable */ return process_escapes(&c->input, &c->output, &c->extended, buf, len); } -void +static void client_channel_closed(int id, void *arg) { - if (id != session_ident) - error("client_channel_closed: id %d != session_ident %d", - id, session_ident); + channel_cancel_cleanup(id); session_closed = 1; - if (in_raw_mode()) - leave_raw_mode(); + leave_raw_mode(); } /* * Implements the interactive session with the server. This is called after * the user has been authenticated, and a command has been started on the - * remote host. If escape_char != -1, it is the character used as an escape - * character for terminating or suspending the session. + * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character + * used as an escape character for terminating or suspending the session. */ int @@ -768,7 +1147,7 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) { fd_set *readset = NULL, *writeset = NULL; double start_time, total_time; - int max_fd = 0, len, rekeying = 0; + int max_fd = 0, max_fd2 = 0, len, rekeying = 0, nalloc = 0; char buf[100]; debug("Entering interactive session."); @@ -784,6 +1163,8 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) connection_in = packet_get_connection_in(); connection_out = packet_get_connection_out(); max_fd = MAX(connection_in, connection_out); + if (control_fd != -1) + max_fd = MAX(max_fd, control_fd); if (!compat20) { /* enable nonblocking unless tty */ @@ -810,11 +1191,16 @@ 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); - signal(SIGPIPE, SIG_IGN); + /* + * 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); @@ -823,7 +1209,7 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) if (compat20) { session_ident = ssh2_chan_id; - if (escape_char != -1) + if (escape_char != SSH_ESCAPECHAR_NONE) channel_register_filter(session_ident, simple_escape_filter); if (session_ident != -1) @@ -875,8 +1261,9 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) * Wait until we have something to do (something becomes * available on one of the descriptors). */ + max_fd2 = max_fd; client_wait_until_can_do_something(&readset, &writeset, - &max_fd, rekeying); + &max_fd2, &nalloc, rekeying); if (quit_pending) break; @@ -884,9 +1271,8 @@ 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; @@ -896,6 +1282,9 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) /* Buffer input from the connection. */ client_process_net_input(readset); + /* Accept control connections. */ + client_process_control(readset); + if (quit_pending) break; @@ -924,8 +1313,31 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) if (have_pty) signal(SIGWINCH, SIG_DFL); - /* Stop listening for connections. */ - channel_stop_listening(); + channel_free_all(); + + if (have_pty) + leave_raw_mode(); + + /* restore blocking io */ + if (!isatty(fileno(stdin))) + unset_nonblock(fileno(stdin)); + if (!isatty(fileno(stdout))) + unset_nonblock(fileno(stdout)); + if (!isatty(fileno(stderr))) + unset_nonblock(fileno(stderr)); + + /* + * 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 @@ -935,6 +1347,7 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host); buffer_append(&stderr_buffer, buf, strlen(buf)); } + /* Output any buffered data for stdout. */ while (buffer_len(&stdout_buffer) > 0) { len = write(fileno(stdout), buffer_ptr(&stdout_buffer), @@ -959,9 +1372,6 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) stderr_bytes += len; } - if (have_pty) - leave_raw_mode(); - /* Clear and free any buffers. */ memset(buf, 0, sizeof(buf)); buffer_free(&stdin_buffer); @@ -971,11 +1381,11 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) /* Report bytes transferred, and transfer rates. */ total_time = get_current_time() - start_time; debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds", - stdin_bytes, stdout_bytes, stderr_bytes, total_time); + stdin_bytes, stdout_bytes, stderr_bytes, total_time); if (total_time > 0) debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f", - stdin_bytes / total_time, stdout_bytes / total_time, - stderr_bytes / total_time); + stdin_bytes / total_time, stdout_bytes / total_time, + stderr_bytes / total_time); /* Return the exit status of the program. */ debug("Exit status %d", exit_status); @@ -984,31 +1394,31 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) /*********/ -void -client_input_stdout_data(int type, int plen, void *ctxt) +static void +client_input_stdout_data(int type, u_int32_t seq, void *ctxt) { u_int data_len; char *data = packet_get_string(&data_len); - packet_integrity_check(plen, 4 + data_len, type); + packet_check_eom(); buffer_append(&stdout_buffer, data, data_len); memset(data, 0, data_len); xfree(data); } -void -client_input_stderr_data(int type, int plen, void *ctxt) +static void +client_input_stderr_data(int type, u_int32_t seq, void *ctxt) { u_int data_len; char *data = packet_get_string(&data_len); - packet_integrity_check(plen, 4 + data_len, type); + packet_check_eom(); buffer_append(&stderr_buffer, data, data_len); memset(data, 0, data_len); xfree(data); } -void -client_input_exit_status(int type, int plen, void *ctxt) +static void +client_input_exit_status(int type, u_int32_t seq, void *ctxt) { - packet_integrity_check(plen, 4, type); exit_status = packet_get_int(); + packet_check_eom(); /* Acknowledge the exit. */ packet_start(SSH_CMSG_EXIT_CONFIRMATION); packet_send(); @@ -1020,45 +1430,87 @@ client_input_exit_status(int type, int plen, 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(); +} -Channel * +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, newch; + int sock; /* Get rest of the packet */ listen_address = packet_get_string(NULL); listen_port = packet_get_int(); originator_address = packet_get_string(NULL); originator_port = packet_get_int(); - packet_done(); + packet_check_eom(); debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d", listen_address, listen_port, originator_address, originator_port); - sock = channel_connect_by_listen_adress(listen_port); - if (sock >= 0) { - newch = channel_new("forwarded-tcpip", - SSH_CHANNEL_CONNECTING, sock, sock, -1, - CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, - xstrdup(originator_address), 1); - c = channel_lookup(newch); + sock = channel_connect_by_listen_address(listen_port); + if (sock < 0) { + xfree(originator_address); + xfree(listen_address); + return NULL; } + c = channel_new("forwarded-tcpip", + SSH_CHANNEL_CONNECTING, sock, sock, -1, + CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, + originator_address, 1); xfree(originator_address); xfree(listen_address); return c; } -Channel* +static Channel * client_request_x11(const char *request_type, int rchan) { Channel *c = NULL; char *originator; int originator_port; - int sock, newch; + int sock; if (!options.forward_x11) { error("Warning: ssh server tried X11 forwarding."); @@ -1072,27 +1524,26 @@ client_request_x11(const char *request_type, int rchan) } else { originator_port = packet_get_int(); } - packet_done(); + packet_check_eom(); /* XXX check permission */ debug("client_request_x11: request from %s %d", originator, originator_port); - sock = x11_connect_display(); - if (sock >= 0) { - newch = channel_new("x11", - SSH_CHANNEL_X11_OPEN, sock, sock, -1, - CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, - xstrdup("x11"), 1); - c = channel_lookup(newch); - } xfree(originator); + sock = x11_connect_display(); + if (sock < 0) + return NULL; + c = channel_new("x11", + SSH_CHANNEL_X11_OPEN, sock, sock, -1, + CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); + c->force_drain = 1; return c; } -Channel* +static Channel * client_request_agent(const char *request_type, int rchan) { Channel *c = NULL; - int sock, newch; + int sock; if (!options.forward_agent) { error("Warning: ssh server tried agent forwarding."); @@ -1100,26 +1551,24 @@ client_request_agent(const char *request_type, int rchan) return NULL; } sock = ssh_get_authentication_socket(); - if (sock >= 0) { - newch = 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); - c = channel_lookup(newch); - } + if (sock < 0) + return NULL; + c = channel_new("authentication agent connection", + SSH_CHANNEL_OPEN, sock, sock, -1, + CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0, + "authentication agent connection", 1); + c->force_drain = 1; return c; } /* XXXX move to generic input handler */ -void -client_input_channel_open(int type, int plen, void *ctxt) +static void +client_input_channel_open(int type, u_int32_t seq, void *ctxt) { 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(); @@ -1142,31 +1591,32 @@ client_input_channel_open(int type, int plen, void *ctxt) c->remote_id = rchan; c->remote_window = rwindow; c->remote_maxpacket = rmaxpack; - - packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(c->remote_id); - packet_put_int(c->self); - packet_put_int(c->local_window); - packet_put_int(c->local_maxpacket); - packet_send(); + if (c->type != SSH_CHANNEL_CONNECTING) { + packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); + packet_put_int(c->remote_id); + packet_put_int(c->self); + packet_put_int(c->local_window); + packet_put_int(c->local_maxpacket); + packet_send(); + } } else { debug("failure %s", ctype); packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); packet_put_int(rchan); packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); if (!(datafellows & SSH_BUG_OPENFAILURE)) { - packet_put_cstring("bla bla"); + packet_put_cstring("open failed"); packet_put_cstring(""); } packet_send(); } xfree(ctype); } -void -client_input_channel_req(int type, int plen, void *ctxt) +static void +client_input_channel_req(int type, u_int32_t seq, void *ctxt) { Channel *c = NULL; - int id, reply, success = 0; + int exitval, id, reply, success = 0; char *rtype; id = packet_get_int(); @@ -1176,33 +1626,148 @@ client_input_channel_req(int type, int plen, void *ctxt) debug("client_input_channel_req: channel %d rtype %s reply %d", id, rtype, reply); - if (session_ident == -1) { - error("client_input_channel_req: no channel %d", session_ident); - } else if (id != session_ident) { - error("client_input_channel_req: channel %d: wrong channel: %d", - session_ident, id); - } - c = channel_lookup(id); - if (c == NULL) { + if (id == -1) { + error("client_input_channel_req: request for channel -1"); + } else if ((c = channel_lookup(id)) == NULL) { error("client_input_channel_req: channel %d: unknown channel", id); } else if (strcmp(rtype, "exit-status") == 0) { - success = 1; - exit_status = packet_get_int(); - packet_done(); + exitval = packet_get_int(); + if (id == session_ident) { + success = 1; + exit_status = exitval; + } else if (c->ctl_fd == -1) { + error("client_input_channel_req: unexpected channel %d", + session_ident); + } else { + atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval)); + success = 1; + } + packet_check_eom(); } if (reply) { packet_start(success ? SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); - packet_put_int(c->remote_id); + packet_put_int(id); packet_send(); } 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); +} void +client_session2_setup(int id, int want_tty, int want_subsystem, + const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env, + dispatch_fn *subsys_repl) +{ + int len; + + debug2("%s: id %d", __func__, id); + + if (want_tty) { + struct winsize ws; + struct termios tio; + + /* Store window size in the packet. */ + if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) + memset(&ws, 0, sizeof(ws)); + + channel_request_start(id, "pty-req", 0); + packet_put_cstring(term != NULL ? term : ""); + packet_put_int(ws.ws_col); + packet_put_int(ws.ws_row); + packet_put_int(ws.ws_xpixel); + packet_put_int(ws.ws_ypixel); + tio = get_saved_tio(); + tty_make_modes(-1, tiop != NULL ? tiop : &tio); + packet_send(); + /* XXX wait for reply */ + } + + /* Transfer any environment variables from client to server */ + if (options.num_send_env != 0 && env != NULL) { + int i, j, matched; + char *name, *val; + + debug("Sending environment."); + for (i = 0; env[i] != NULL; i++) { + /* Split */ + name = xstrdup(env[i]); + if ((val = strchr(name, '=')) == NULL) { + free(name); + continue; + } + *val++ = '\0'; + + matched = 0; + for (j = 0; j < options.num_send_env; j++) { + if (match_pattern(name, options.send_env[j])) { + matched = 1; + break; + } + } + if (!matched) { + debug3("Ignored env %s", name); + free(name); + continue; + } + + debug("Sending env %s = %s", name, val); + channel_request_start(id, "env", 0); + packet_put_cstring(name); + packet_put_cstring(val); + packet_send(); + free(name); + } + } + + len = buffer_len(cmd); + if (len > 0) { + if (len > 900) + len = 900; + if (want_subsystem) { + debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd)); + channel_request_start(id, "subsystem", subsys_repl != NULL); + if (subsys_repl != NULL) { + /* register callback for reply */ + /* XXX we assume that client_loop has already been called */ + dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl); + dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl); + } + } else { + debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd)); + channel_request_start(id, "exec", 0); + } + packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); + packet_send(); + } else { + channel_request_start(id, "shell", 0); + packet_send(); + } +} + +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); @@ -1212,11 +1777,16 @@ client_init_dispatch_20(void) 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); } -void +static void client_init_dispatch_13(void) { dispatch_init(NULL); @@ -1231,18 +1801,18 @@ 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); } -void +static void client_init_dispatch_15(void) { client_init_dispatch_13(); dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose); } -void +static void client_init_dispatch(void) { if (compat20) @@ -1252,3 +1822,14 @@ client_init_dispatch(void) else client_init_dispatch_15(); } + +/* client specific fatal cleanup */ +void +cleanup_exit(int i) +{ + leave_raw_mode(); + leave_non_blocking(); + if (options.control_path != NULL && control_fd != -1) + unlink(options.control_path); + _exit(i); +}