X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/5188ba17523a6e5e1ac4b55f910f79610070f9d8..3bcced4c9a1f6c605179089cff82e0aae8d16898:/clientloop.c diff --git a/clientloop.c b/clientloop.c index 9398dc98..c87aa5a0 100644 --- a/clientloop.c +++ b/clientloop.c @@ -1,4 +1,4 @@ -/* $OpenBSD: clientloop.c,v 1.169 2006/07/17 01:31:09 stevesk Exp $ */ +/* $OpenBSD: clientloop.c,v 1.192 2008/05/09 14:18:44 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -62,11 +62,15 @@ #include "includes.h" #include +#include +#include #ifdef HAVE_SYS_STAT_H # include #endif +#ifdef HAVE_SYS_TIME_H +# include +#endif #include -#include #include #include @@ -74,21 +78,26 @@ #include #endif #include +#include +#include +#include +#include #include +#include #include +#include "openbsd-compat/sys-queue.h" +#include "xmalloc.h" #include "ssh.h" #include "ssh1.h" #include "ssh2.h" -#include "xmalloc.h" #include "packet.h" #include "buffer.h" #include "compat.h" #include "channels.h" #include "dispatch.h" -#include "buffer.h" -#include "bufaux.h" #include "key.h" +#include "cipher.h" #include "kex.h" #include "log.h" #include "readconf.h" @@ -112,7 +121,7 @@ extern int stdin_null_flag; extern int no_shell_flag; /* Control socket */ -extern int control_fd; +extern int muxserver_sock; /* * Name of the host we are connecting to. This is the name given on the @@ -149,20 +158,13 @@ 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; -struct confirm_ctx { - int want_tty; - int want_subsys; - int want_x_fwd; - int want_agent_fwd; - Buffer cmd; - char *term; - struct termios tio; - char **env; +struct channel_reply_ctx { + const char *request_type; + int id, do_close; }; /*XXX*/ @@ -282,19 +284,29 @@ client_x11_get_proto(const char *display, const char *xauth_path, generated = 1; } } - snprintf(cmd, sizeof(cmd), - "%s %s%s list %s 2>" _PATH_DEVNULL, - xauth_path, - generated ? "-f " : "" , - generated ? xauthfile : "", - display); - debug2("x11_get_proto: %s", cmd); - f = popen(cmd, "r"); - if (f && fgets(line, sizeof(line), f) && - sscanf(line, "%*s %511s %511s", proto, data) == 2) - got_data = 1; - if (f) - pclose(f); + + /* + * When in untrusted mode, we read the cookie only if it was + * successfully generated as an untrusted one in the step + * above. + */ + if (trusted || generated) { + snprintf(cmd, sizeof(cmd), + "%s %s%s list %s 2>" _PATH_DEVNULL, + xauth_path, + generated ? "-f " : "" , + generated ? xauthfile : "", + display); + debug2("x11_get_proto: %s", cmd); + f = popen(cmd, "r"); + if (f && fgets(line, sizeof(line), f) && + sscanf(line, "%*s %511s %511s", proto, data) == 2) + got_data = 1; + if (f) + pclose(f); + } else + error("Warning: untrusted X11 forwarding setup failed: " + "xauth key data not generated"); } if (do_unlink) { @@ -449,15 +461,17 @@ client_check_window_change(void) static void client_global_request_reply(int type, u_int32_t seq, void *ctxt) { - server_alive_timeouts = 0; + keep_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."); + if (++keep_alive_timeouts > options.server_alive_count_max) { + logit("Timeout, server not responding."); + cleanup_exit(255); + } packet_start(SSH2_MSG_GLOBAL_REQUEST); packet_put_cstring("keepalive@openssh.com"); packet_put_char(1); /* boolean: want reply */ @@ -513,8 +527,8 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, if (packet_have_data_to_write()) FD_SET(connection_out, *writesetp); - if (control_fd != -1) - FD_SET(control_fd, *readsetp); + if (muxserver_sock != -1) + FD_SET(muxserver_sock, *readsetp); /* * Wait for something to happen. This will suspend the process until @@ -625,283 +639,60 @@ client_process_net_input(fd_set *readset) } static void -client_subsystem_reply(int type, u_int32_t seq, void *ctxt) +client_status_confirm(int type, Channel *c, void *ctx) { - 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); + struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; + char errmsg[256]; + int tochan; + + /* XXX supress on mux _client_ quietmode */ + tochan = options.log_level >= SYSLOG_LEVEL_ERROR && + c->ctl_fd != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; + + if (type == SSH2_MSG_CHANNEL_SUCCESS) { + debug2("%s request accepted on channel %d", + cr->request_type, c->self); + } else if (type == SSH2_MSG_CHANNEL_FAILURE) { + if (tochan) { + snprintf(errmsg, sizeof(errmsg), + "%s request failed\r\n", cr->request_type); + } else { + snprintf(errmsg, sizeof(errmsg), + "%s request failed on channel %d", + cr->request_type, c->self); + } + /* If error occurred on primary session channel, then exit */ + if (cr->do_close && c->self == session_ident) + fatal("%s", errmsg); + /* If error occurred on mux client, append to their stderr */ + if (tochan) + buffer_append(&c->extended, errmsg, strlen(errmsg)); + else + error("%s", errmsg); + if (cr->do_close) { + chan_read_failed(c); + chan_write_failed(c); + } } + xfree(cr); } static void -client_extra_session2_setup(int id, void *arg) +client_abandon_status_confirm(Channel *c, void *ctx) { - struct confirm_ctx *cctx = arg; - const char *display; - 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); - - display = getenv("DISPLAY"); - if (cctx->want_x_fwd && options.forward_x11 && display != NULL) { - char *proto, *data; - /* Get reasonable local authentication information. */ - client_x11_get_proto(display, options.xauth_location, - options.forward_x11_trusted, &proto, &data); - /* Request forwarding with authentication spoofing. */ - debug("Requesting X11 forwarding with authentication spoofing."); - x11_request_forwarding_with_spoofing(id, display, proto, data); - /* XXX wait for reply */ - } - - if (cctx->want_agent_fwd && options.forward_agent) { - debug("Requesting authentication agent forwarding."); - channel_request_start(id, "auth-agent-req@openssh.com", 0); - packet_send(); - } - - 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); + xfree(ctx); } static void -client_process_control(fd_set *readset) +client_expect_confirm(int id, const char *request, int do_close) { - Buffer m; - Channel *c; - int client_fd, new_fd[3], ver, allowed; - socklen_t addrlen; - struct sockaddr_storage addr; - struct confirm_ctx *cctx; - char *cmd; - u_int i, len, env_len, command, flags; - uid_t euid; - gid_t egid; - - /* - * Accept connection on control socket - */ - if (control_fd == -1 || !FD_ISSET(control_fd, readset)) - return; + struct channel_reply_ctx *cr = xmalloc(sizeof(*cr)); - 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; - } + cr->request_type = request; + cr->do_close = do_close; - 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; - } - - unset_nonblock(client_fd); - - /* Read command */ - buffer_init(&m); - 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)) != SSHMUX_VER) { - error("%s: wrong client version %d", __func__, ver); - buffer_free(&m); - close(client_fd); - return; - } - - allowed = 1; - command = buffer_get_int(&m); - flags = buffer_get_int(&m); - - buffer_clear(&m); - - switch (command) { - case SSHMUX_COMMAND_OPEN: - if (options.control_master == SSHCTL_MASTER_ASK || - options.control_master == SSHCTL_MASTER_AUTO_ASK) - allowed = ask_permission("Allow shared connection " - "to %s? ", host); - /* continue below */ - break; - case SSHMUX_COMMAND_TERMINATE: - if (options.control_master == SSHCTL_MASTER_ASK || - options.control_master == SSHCTL_MASTER_AUTO_ASK) - allowed = ask_permission("Terminate shared connection " - "to %s? ", host); - if (allowed) - quit_pending = 1; - /* FALLTHROUGH */ - case SSHMUX_COMMAND_ALIVE_CHECK: - /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */ - buffer_clear(&m); - buffer_put_int(&m, allowed); - buffer_put_int(&m, getpid()); - if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { - error("%s: client msg_send failed", __func__); - close(client_fd); - buffer_free(&m); - return; - } - buffer_free(&m); - close(client_fd); - return; - default: - error("Unsupported command %d", command); - buffer_free(&m); - close(client_fd); - return; - } - - /* Reply for SSHMUX_COMMAND_OPEN */ - buffer_clear(&m); - buffer_put_int(&m, allowed); - buffer_put_int(&m, getpid()); - if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { - error("%s: client msg_send failed", __func__); - close(client_fd); - buffer_free(&m); - return; - } - - if (!allowed) { - error("Refused control connection"); - close(client_fd); - buffer_free(&m); - return; - } - - buffer_clear(&m); - 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)) != SSHMUX_VER) { - error("%s: wrong client version %d", __func__, ver); - buffer_free(&m); - close(client_fd); - return; - } - - cctx = xcalloc(1, sizeof(*cctx)); - cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0; - cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0; - cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0; - cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0; - 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 = xcalloc(env_len + 1, sizeof(*cctx->env)); - 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); - xfree(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)); - - /* This roundtrip is just for synchronisation of ttymodes */ - buffer_clear(&m); - if (ssh_msg_send(client_fd, SSHMUX_VER, &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); - xfree(cctx->term); - if (env_len != 0) { - for (i = 0; i < env_len; i++) - xfree(cctx->env[i]); - xfree(cctx->env); - } - 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); + channel_register_status_confirm(id, client_status_confirm, + client_abandon_status_confirm, cr); } static void @@ -914,12 +705,15 @@ process_cmdline(void) u_short cancel_port; Forward fwd; + bzero(&fwd, sizeof(fwd)); + fwd.listen_host = fwd.connect_host = NULL; + 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)) + while (isspace(*s)) s++; if (*s == '-') s++; /* Skip cmdline '-', if any */ @@ -966,9 +760,8 @@ process_cmdline(void) goto out; } - s++; - while (*s && isspace(*s)) - s++; + while (isspace(*++s)) + ; if (delete) { cancel_port = 0; @@ -1014,6 +807,10 @@ out: enter_raw_mode(); if (cmd) xfree(cmd); + if (fwd.listen_host != NULL) + xfree(fwd.listen_host); + if (fwd.connect_host != NULL) + xfree(fwd.connect_host); } /* process the characters one by one */ @@ -1319,7 +1116,9 @@ client_process_buffered_input_packets(void) static int simple_escape_filter(Channel *c, char *buf, int len) { - /* XXX we assume c->extended is writeable */ + if (c->extended_usage != CHAN_EXTENDED_WRITE) + return 0; + return process_escapes(&c->input, &c->output, &c->extended, buf, len); } @@ -1360,8 +1159,8 @@ 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 (muxserver_sock != -1) + max_fd = MAX(max_fd, muxserver_sock); if (!compat20) { /* enable nonblocking unless tty */ @@ -1481,7 +1280,10 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id) client_process_net_input(readset); /* Accept control connections. */ - client_process_control(readset); + if (muxserver_sock != -1 &&FD_ISSET(muxserver_sock, readset)) { + if (muxserver_accept_control()) + quit_pending = 1; + } if (quit_pending) break; @@ -1674,7 +1476,6 @@ client_request_forwarded_tcpip(const char *request_type, int rchan) Channel *c = NULL; char *listen_address, *originator_address; int listen_port, originator_port; - int sock; /* Get rest of the packet */ listen_address = packet_get_string(NULL); @@ -1683,19 +1484,13 @@ client_request_forwarded_tcpip(const char *request_type, int rchan) originator_port = packet_get_int(); packet_check_eom(); - debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d", - listen_address, listen_port, originator_address, originator_port); + debug("client_request_forwarded_tcpip: listen %s port %d, " + "originator %s port %d", listen_address, listen_port, + originator_address, originator_port); + + c = channel_connect_by_listen_address(listen_port, + "forwarded-tcpip", originator_address); - 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; @@ -1747,17 +1542,61 @@ client_request_agent(const char *request_type, int rchan) error("Warning: this is probably a break-in attempt by a malicious server."); return NULL; } - sock = ssh_get_authentication_socket(); + sock = ssh_get_authentication_socket(); 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, + CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "authentication agent connection", 1); c->force_drain = 1; return c; } +int +client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun) +{ + Channel *c; + int fd; + + if (tun_mode == SSH_TUNMODE_NO) + return 0; + + if (!compat20) { + error("Tunnel forwarding is not support for protocol 1"); + return -1; + } + + debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); + + /* Open local tunnel device */ + if ((fd = tun_open(local_tun, tun_mode)) == -1) { + error("Tunnel device open failed."); + return -1; + } + + c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, + CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); + c->datagram = 1; + +#if defined(SSH_TUN_FILTER) + if (options.tun_open == SSH_TUNMODE_POINTOPOINT) + channel_register_filter(c->self, sys_tun_infilter, + sys_tun_outfilter); +#endif + + packet_start(SSH2_MSG_CHANNEL_OPEN); + packet_put_cstring("tun@openssh.com"); + packet_put_int(c->self); + packet_put_int(c->local_window_max); + packet_put_int(c->local_maxpacket); + packet_put_int(tun_mode); + packet_put_int(remote_tun); + packet_send(); + + return 0; +} + /* XXXX move to generic input handler */ static void client_input_channel_open(int type, u_int32_t seq, void *ctxt) @@ -1871,8 +1710,7 @@ client_input_global_request(int type, u_int32_t seq, void *ctxt) 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) + const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env) { int len; Channel *c = NULL; @@ -1890,7 +1728,8 @@ client_session2_setup(int id, int want_tty, int want_subsystem, if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0) memset(&ws, 0, sizeof(ws)); - channel_request_start(id, "pty-req", 0); + channel_request_start(id, "pty-req", 1); + client_expect_confirm(id, "PTY allocation", 0); packet_put_cstring(term != NULL ? term : ""); packet_put_int((u_int)ws.ws_col); packet_put_int((u_int)ws.ws_row); @@ -1945,22 +1784,21 @@ client_session2_setup(int id, int want_tty, int want_subsystem, 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); - } + debug("Sending subsystem: %.*s", + len, (u_char*)buffer_ptr(cmd)); + channel_request_start(id, "subsystem", 1); + client_expect_confirm(id, "subsystem", 1); } else { - debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd)); - channel_request_start(id, "exec", 0); + debug("Sending command: %.*s", + len, (u_char*)buffer_ptr(cmd)); + channel_request_start(id, "exec", 1); + client_expect_confirm(id, "exec", 1); } packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); packet_send(); } else { - channel_request_start(id, "shell", 0); + channel_request_start(id, "shell", 1); + client_expect_confirm(id, "shell", 1); packet_send(); } } @@ -1979,6 +1817,8 @@ 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_CHANNEL_SUCCESS, &channel_input_status_confirm); + dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); /* rekeying */ @@ -2031,7 +1871,7 @@ cleanup_exit(int i) { leave_raw_mode(); leave_non_blocking(); - if (options.control_path != NULL && control_fd != -1) + if (options.control_path != NULL && muxserver_sock != -1) unlink(options.control_path); _exit(i); }