/* * PLink - a command-line (stdin/stdout) variant of PuTTY. */ #include #include #include #include #include #include #include #include #include #include #include #include #ifndef HAVE_NO_SYS_SELECT_H #include #endif #define PUTTY_DO_GLOBALS /* actually _define_ globals */ #include "putty.h" #include "storage.h" #include "tree234.h" #define MAX_STDIN_BACKLOG 4096 static LogContext *logctx; static struct termios orig_termios; void modalfatalbox(const char *p, ...) { struct termios cf; va_list ap; premsg(&cf); fprintf(stderr, "FATAL ERROR: "); va_start(ap, p); vfprintf(stderr, p, ap); va_end(ap); fputc('\n', stderr); postmsg(&cf); if (logctx) { log_free(logctx); logctx = NULL; } cleanup_exit(1); } void nonfatal(const char *p, ...) { struct termios cf; va_list ap; premsg(&cf); fprintf(stderr, "ERROR: "); va_start(ap, p); vfprintf(stderr, p, ap); va_end(ap); fputc('\n', stderr); postmsg(&cf); } void connection_fatal(Frontend *frontend, const char *p, ...) { struct termios cf; va_list ap; premsg(&cf); fprintf(stderr, "FATAL ERROR: "); va_start(ap, p); vfprintf(stderr, p, ap); va_end(ap); fputc('\n', stderr); postmsg(&cf); if (logctx) { log_free(logctx); logctx = NULL; } cleanup_exit(1); } void cmdline_error(const char *p, ...) { struct termios cf; va_list ap; premsg(&cf); fprintf(stderr, "plink: "); va_start(ap, p); vfprintf(stderr, p, ap); va_end(ap); fputc('\n', stderr); postmsg(&cf); exit(1); } static int local_tty = FALSE; /* do we have a local tty? */ static Backend *backend; static Conf *conf; /* * Default settings that are specific to Unix plink. */ char *platform_default_s(const char *name) { if (!strcmp(name, "TermType")) return dupstr(getenv("TERM")); if (!strcmp(name, "SerialLine")) return dupstr("/dev/ttyS0"); return NULL; } int platform_default_i(const char *name, int def) { return def; } FontSpec *platform_default_fontspec(const char *name) { return fontspec_new(""); } Filename *platform_default_filename(const char *name) { if (!strcmp(name, "LogFileName")) return filename_from_str("putty.log"); else return filename_from_str(""); } char *x_get_default(const char *key) { return NULL; /* this is a stub */ } int term_ldisc(Terminal *term, int mode) { return FALSE; } void frontend_echoedit_update(Frontend *frontend, int echo, int edit) { /* Update stdin read mode to reflect changes in line discipline. */ struct termios mode; if (!local_tty) return; mode = orig_termios; if (echo) mode.c_lflag |= ECHO; else mode.c_lflag &= ~ECHO; if (edit) { mode.c_iflag |= ICRNL; mode.c_lflag |= ISIG | ICANON; mode.c_oflag |= OPOST; } else { mode.c_iflag &= ~ICRNL; mode.c_lflag &= ~(ISIG | ICANON); mode.c_oflag &= ~OPOST; /* Solaris sets these to unhelpful values */ mode.c_cc[VMIN] = 1; mode.c_cc[VTIME] = 0; /* FIXME: perhaps what we do with IXON/IXOFF should be an * argument to frontend_echoedit_update(), to allow * implementation of SSH-2 "xon-xoff" and Rlogin's * equivalent? */ mode.c_iflag &= ~IXON; mode.c_iflag &= ~IXOFF; } /* * Mark parity errors and (more important) BREAK on input. This * is more complex than it need be because POSIX-2001 suggests * that escaping of valid 0xff in the input stream is dependent on * IGNPAR being clear even though marking of BREAK isn't. NetBSD * 2.0 goes one worse and makes it dependent on INPCK too. We * deal with this by forcing these flags into a useful state and * then faking the state in which we found them in from_tty() if * we get passed a parity or framing error. */ mode.c_iflag = (mode.c_iflag | INPCK | PARMRK) & ~IGNPAR; tcsetattr(STDIN_FILENO, TCSANOW, &mode); } /* Helper function to extract a special character from a termios. */ static char *get_ttychar(struct termios *t, int index) { cc_t c = t->c_cc[index]; #if defined(_POSIX_VDISABLE) if (c == _POSIX_VDISABLE) return dupstr(""); #endif return dupprintf("^<%d>", c); } char *get_ttymode(Frontend *frontend, const char *mode) { /* * Propagate appropriate terminal modes from the local terminal, * if any. */ if (!local_tty) return NULL; #define GET_CHAR(ourname, uxname) \ do { \ if (strcmp(mode, ourname) == 0) \ return get_ttychar(&orig_termios, uxname); \ } while(0) #define GET_BOOL(ourname, uxname, uxmemb, transform) \ do { \ if (strcmp(mode, ourname) == 0) { \ int b = (orig_termios.uxmemb & uxname) != 0; \ transform; \ return dupprintf("%d", b); \ } \ } while (0) /* * Modes that want to be the same on all terminal devices involved. */ /* All the special characters supported by SSH */ #if defined(VINTR) GET_CHAR("INTR", VINTR); #endif #if defined(VQUIT) GET_CHAR("QUIT", VQUIT); #endif #if defined(VERASE) GET_CHAR("ERASE", VERASE); #endif #if defined(VKILL) GET_CHAR("KILL", VKILL); #endif #if defined(VEOF) GET_CHAR("EOF", VEOF); #endif #if defined(VEOL) GET_CHAR("EOL", VEOL); #endif #if defined(VEOL2) GET_CHAR("EOL2", VEOL2); #endif #if defined(VSTART) GET_CHAR("START", VSTART); #endif #if defined(VSTOP) GET_CHAR("STOP", VSTOP); #endif #if defined(VSUSP) GET_CHAR("SUSP", VSUSP); #endif #if defined(VDSUSP) GET_CHAR("DSUSP", VDSUSP); #endif #if defined(VREPRINT) GET_CHAR("REPRINT", VREPRINT); #endif #if defined(VWERASE) GET_CHAR("WERASE", VWERASE); #endif #if defined(VLNEXT) GET_CHAR("LNEXT", VLNEXT); #endif #if defined(VFLUSH) GET_CHAR("FLUSH", VFLUSH); #endif #if defined(VSWTCH) GET_CHAR("SWTCH", VSWTCH); #endif #if defined(VSTATUS) GET_CHAR("STATUS", VSTATUS); #endif #if defined(VDISCARD) GET_CHAR("DISCARD", VDISCARD); #endif /* Modes that "configure" other major modes. These should probably be * considered as user preferences. */ /* Configuration of ICANON */ #if defined(ECHOK) GET_BOOL("ECHOK", ECHOK, c_lflag, ); #endif #if defined(ECHOKE) GET_BOOL("ECHOKE", ECHOKE, c_lflag, ); #endif #if defined(ECHOE) GET_BOOL("ECHOE", ECHOE, c_lflag, ); #endif #if defined(ECHONL) GET_BOOL("ECHONL", ECHONL, c_lflag, ); #endif #if defined(XCASE) GET_BOOL("XCASE", XCASE, c_lflag, ); #endif #if defined(IUTF8) GET_BOOL("IUTF8", IUTF8, c_iflag, ); #endif /* Configuration of ECHO */ #if defined(ECHOCTL) GET_BOOL("ECHOCTL", ECHOCTL, c_lflag, ); #endif /* Configuration of IXON/IXOFF */ #if defined(IXANY) GET_BOOL("IXANY", IXANY, c_iflag, ); #endif /* Configuration of OPOST */ #if defined(OLCUC) GET_BOOL("OLCUC", OLCUC, c_oflag, ); #endif #if defined(ONLCR) GET_BOOL("ONLCR", ONLCR, c_oflag, ); #endif #if defined(OCRNL) GET_BOOL("OCRNL", OCRNL, c_oflag, ); #endif #if defined(ONOCR) GET_BOOL("ONOCR", ONOCR, c_oflag, ); #endif #if defined(ONLRET) GET_BOOL("ONLRET", ONLRET, c_oflag, ); #endif /* * Modes that want to be set in only one place, and that we have * squashed locally. */ #if defined(ISIG) GET_BOOL("ISIG", ISIG, c_lflag, ); #endif #if defined(ICANON) GET_BOOL("ICANON", ICANON, c_lflag, ); #endif #if defined(ECHO) GET_BOOL("ECHO", ECHO, c_lflag, ); #endif #if defined(IXON) GET_BOOL("IXON", IXON, c_iflag, ); #endif #if defined(IXOFF) GET_BOOL("IXOFF", IXOFF, c_iflag, ); #endif #if defined(OPOST) GET_BOOL("OPOST", OPOST, c_oflag, ); #endif /* * We do not propagate the following modes: * - Parity/serial settings, which are a local affair and don't * make sense propagated over SSH's 8-bit byte-stream. * IGNPAR PARMRK INPCK CS7 CS8 PARENB PARODD * - Things that want to be enabled in one place that we don't * squash locally. * IUCLC * - Status bits. * PENDIN * - Things I don't know what to do with. (FIXME) * ISTRIP IMAXBEL NOFLSH TOSTOP IEXTEN * INLCR IGNCR ICRNL */ #undef GET_CHAR #undef GET_BOOL /* Fall through to here for unrecognised names, or ones that are * unsupported on this platform */ return NULL; } void cleanup_termios(void) { if (local_tty) tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios); } bufchain stdout_data, stderr_data; enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof; int try_output(int is_stderr) { bufchain *chain = (is_stderr ? &stderr_data : &stdout_data); int fd = (is_stderr ? STDERR_FILENO : STDOUT_FILENO); void *senddata; int sendlen, ret; if (bufchain_size(chain) > 0) { int prev_nonblock = nonblock(fd); do { bufchain_prefix(chain, &senddata, &sendlen); ret = write(fd, senddata, sendlen); if (ret > 0) bufchain_consume(chain, ret); } while (ret == sendlen && bufchain_size(chain) != 0); if (!prev_nonblock) no_nonblock(fd); if (ret < 0 && errno != EAGAIN) { perror(is_stderr ? "stderr: write" : "stdout: write"); exit(1); } } if (outgoingeof == EOF_PENDING && bufchain_size(&stdout_data) == 0) { close(STDOUT_FILENO); outgoingeof = EOF_SENT; } return bufchain_size(&stdout_data) + bufchain_size(&stderr_data); } int from_backend(Frontend *frontend, int is_stderr, const void *data, int len) { if (is_stderr) { bufchain_add(&stderr_data, data, len); return try_output(TRUE); } else { assert(outgoingeof == EOF_NO); bufchain_add(&stdout_data, data, len); return try_output(FALSE); } } int from_backend_eof(Frontend *frontend) { assert(outgoingeof == EOF_NO); outgoingeof = EOF_PENDING; try_output(FALSE); return FALSE; /* do not respond to incoming EOF with outgoing */ } int get_userpass_input(prompts_t *p, bufchain *input) { int ret; ret = cmdline_get_passwd_input(p); if (ret == -1) ret = console_get_userpass_input(p); return ret; } /* * Handle data from a local tty in PARMRK format. */ static void from_tty(void *vbuf, unsigned len) { char *p, *q, *end, *buf = vbuf; static enum {NORMAL, FF, FF00} state = NORMAL; p = buf; end = buf + len; while (p < end) { switch (state) { case NORMAL: if (*p == '\xff') { p++; state = FF; } else { q = memchr(p, '\xff', end - p); if (q == NULL) q = end; backend_send(backend, p, q - p); p = q; } break; case FF: if (*p == '\xff') { backend_send(backend, p, 1); p++; state = NORMAL; } else if (*p == '\0') { p++; state = FF00; } else abort(); break; case FF00: if (*p == '\0') { backend_special(backend, SS_BRK, 0); } else { /* * Pretend that PARMRK wasn't set. This involves * faking what INPCK and IGNPAR would have done if * we hadn't overridden them. Unfortunately, we * can't do this entirely correctly because INPCK * distinguishes between framing and parity * errors, but PARMRK format represents both in * the same way. We assume that parity errors are * more common than framing errors, and hence * treat all input errors as being subject to * INPCK. */ if (orig_termios.c_iflag & INPCK) { /* If IGNPAR is set, we throw away the character. */ if (!(orig_termios.c_iflag & IGNPAR)) { /* PE/FE get passed on as NUL. */ *p = 0; backend_send(backend, p, 1); } } else { /* INPCK not set. Assume we got a parity error. */ backend_send(backend, p, 1); } } p++; state = NORMAL; } } } int signalpipe[2]; void sigwinch(int signum) { if (write(signalpipe[1], "x", 1) <= 0) /* not much we can do about it */; } /* * In Plink our selects are synchronous, so these functions are * empty stubs. */ uxsel_id *uxsel_input_add(int fd, int rwx) { return NULL; } void uxsel_input_remove(uxsel_id *id) { } /* * Short description of parameters. */ static void usage(void) { printf("Plink: command-line connection utility\n"); printf("%s\n", ver); printf("Usage: plink [options] [user@]host [command]\n"); printf(" (\"host\" can also be a PuTTY saved session name)\n"); printf("Options:\n"); printf(" -V print version information and exit\n"); printf(" -pgpfp print PGP key fingerprints and exit\n"); printf(" -v show verbose messages\n"); printf(" -load sessname Load settings from saved session\n"); printf(" -ssh -telnet -rlogin -raw -serial\n"); printf(" force use of a particular protocol\n"); printf(" -P port connect to specified port\n"); printf(" -l user connect with specified username\n"); printf(" -batch disable all interactive prompts\n"); printf(" -proxycmd command\n"); printf(" use 'command' as local proxy\n"); printf(" -sercfg configuration-string (e.g. 19200,8,n,1,X)\n"); printf(" Specify the serial configuration (serial only)\n"); printf("The following options only apply to SSH connections:\n"); printf(" -pw passw login with specified password\n"); printf(" -D [listen-IP:]listen-port\n"); printf(" Dynamic SOCKS-based port forwarding\n"); printf(" -L [listen-IP:]listen-port:host:port\n"); printf(" Forward local port to remote address\n"); printf(" -R [listen-IP:]listen-port:host:port\n"); printf(" Forward remote port to local address\n"); printf(" -X -x enable / disable X11 forwarding\n"); printf(" -A -a enable / disable agent forwarding\n"); printf(" -t -T enable / disable pty allocation\n"); printf(" -1 -2 force use of particular protocol version\n"); printf(" -4 -6 force use of IPv4 or IPv6\n"); printf(" -C enable compression\n"); printf(" -i key private key file for user authentication\n"); printf(" -noagent disable use of Pageant\n"); printf(" -agent enable use of Pageant\n"); printf(" -noshare disable use of connection sharing\n"); printf(" -share enable use of connection sharing\n"); printf(" -hostkey aa:bb:cc:...\n"); printf(" manually specify a host key (may be repeated)\n"); printf(" -m file read remote command(s) from file\n"); printf(" -s remote command is an SSH subsystem (SSH-2 only)\n"); printf(" -N don't start a shell/command (SSH-2 only)\n"); printf(" -nc host:port\n"); printf(" open tunnel in place of session (SSH-2 only)\n"); printf(" -sshlog file\n"); printf(" -sshrawlog file\n"); printf(" log protocol details to a file\n"); printf(" -shareexists\n"); printf(" test whether a connection-sharing upstream exists\n"); exit(1); } static void version(void) { char *buildinfo_text = buildinfo("\n"); printf("plink: %s\n%s\n", ver, buildinfo_text); sfree(buildinfo_text); exit(0); } void frontend_net_error_pending(void) {} const int share_can_be_downstream = TRUE; const int share_can_be_upstream = TRUE; const int buildinfo_gtk_relevant = FALSE; int main(int argc, char **argv) { int sending; int *fdlist; int fd; int i, fdcount, fdsize, fdstate; int exitcode; int errors; int use_subsystem = 0; int just_test_share_exists = FALSE; unsigned long now; struct winsize size; const struct Backend_vtable *backvt; fdlist = NULL; fdcount = fdsize = 0; /* * Initialise port and protocol to sensible defaults. (These * will be overridden by more or less anything.) */ default_protocol = PROT_SSH; default_port = 22; bufchain_init(&stdout_data); bufchain_init(&stderr_data); outgoingeof = EOF_NO; flags = FLAG_STDERR_TTY; cmdline_tooltype |= (TOOLTYPE_HOST_ARG | TOOLTYPE_HOST_ARG_CAN_BE_SESSION | TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX | TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD); stderr_tty_init(); /* * Process the command line. */ conf = conf_new(); do_defaults(NULL, conf); loaded_session = FALSE; default_protocol = conf_get_int(conf, CONF_protocol); default_port = conf_get_int(conf, CONF_port); errors = 0; { /* * Override the default protocol if PLINK_PROTOCOL is set. */ char *p = getenv("PLINK_PROTOCOL"); if (p) { const struct Backend_vtable *vt = backend_vt_from_name(p); if (vt) { default_protocol = vt->protocol; default_port = vt->default_port; conf_set_int(conf, CONF_protocol, default_protocol); conf_set_int(conf, CONF_port, default_port); } } } while (--argc) { char *p = *++argv; int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL), 1, conf); if (ret == -2) { fprintf(stderr, "plink: option \"%s\" requires an argument\n", p); errors = 1; } else if (ret == 2) { --argc, ++argv; } else if (ret == 1) { continue; } else if (!strcmp(p, "-batch")) { console_batch_mode = 1; } else if (!strcmp(p, "-s")) { /* Save status to write to conf later. */ use_subsystem = 1; } else if (!strcmp(p, "-V") || !strcmp(p, "--version")) { version(); } else if (!strcmp(p, "--help")) { usage(); exit(0); } else if (!strcmp(p, "-pgpfp")) { pgp_fingerprints(); exit(1); } else if (!strcmp(p, "-o")) { if (argc <= 1) { fprintf(stderr, "plink: option \"-o\" requires an argument\n"); errors = 1; } else { --argc; provide_xrm_string(*++argv); } } else if (!strcmp(p, "-shareexists")) { just_test_share_exists = TRUE; } else if (!strcmp(p, "-fuzznet")) { conf_set_int(conf, CONF_proxy_type, PROXY_FUZZ); conf_set_str(conf, CONF_proxy_telnet_command, "%host"); } else if (*p != '-') { char *command; int cmdlen, cmdsize; cmdlen = cmdsize = 0; command = NULL; while (argc) { while (*p) { if (cmdlen >= cmdsize) { cmdsize = cmdlen + 512; command = sresize(command, cmdsize, char); } command[cmdlen++]=*p++; } if (cmdlen >= cmdsize) { cmdsize = cmdlen + 512; command = sresize(command, cmdsize, char); } command[cmdlen++]=' '; /* always add trailing space */ if (--argc) p = *++argv; } if (cmdlen) command[--cmdlen]='\0'; /* change trailing blank to NUL */ conf_set_str(conf, CONF_remote_cmd, command); conf_set_str(conf, CONF_remote_cmd2, ""); conf_set_int(conf, CONF_nopty, TRUE); /* command => no tty */ break; /* done with cmdline */ } else { fprintf(stderr, "plink: unknown option \"%s\"\n", p); errors = 1; } } if (errors) return 1; if (!cmdline_host_ok(conf)) { usage(); } prepare_session(conf); /* * Perform command-line overrides on session configuration. */ cmdline_run_saved(conf); /* * If we have no better ideas for the remote username, use the local * one, as 'ssh' does. */ if (conf_get_str(conf, CONF_username)[0] == '\0') { char *user = get_username(); if (user) { conf_set_str(conf, CONF_username, user); sfree(user); } } /* * Apply subsystem status. */ if (use_subsystem) conf_set_int(conf, CONF_ssh_subsys, TRUE); if (!*conf_get_str(conf, CONF_remote_cmd) && !*conf_get_str(conf, CONF_remote_cmd2) && !*conf_get_str(conf, CONF_ssh_nc_host)) flags |= FLAG_INTERACTIVE; /* * Select protocol. This is farmed out into a table in a * separate file to enable an ssh-free variant. */ backvt = backend_vt_from_proto(conf_get_int(conf, CONF_protocol)); if (!backvt) { fprintf(stderr, "Internal fault: Unsupported protocol found\n"); return 1; } /* * Block SIGPIPE, so that we'll get EPIPE individually on * particular network connections that go wrong. */ putty_signal(SIGPIPE, SIG_IGN); /* * Set up the pipe we'll use to tell us about SIGWINCH. */ if (pipe(signalpipe) < 0) { perror("pipe"); exit(1); } /* We don't want the signal handler to block if the pipe's full. */ nonblock(signalpipe[0]); nonblock(signalpipe[1]); cloexec(signalpipe[0]); cloexec(signalpipe[1]); putty_signal(SIGWINCH, sigwinch); /* * Now that we've got the SIGWINCH handler installed, try to find * out the initial terminal size. */ if (ioctl(STDIN_FILENO, TIOCGWINSZ, &size) >= 0) { conf_set_int(conf, CONF_width, size.ws_col); conf_set_int(conf, CONF_height, size.ws_row); } sk_init(); uxsel_init(); /* * Plink doesn't provide any way to add forwardings after the * connection is set up, so if there are none now, we can safely set * the "simple" flag. */ if (conf_get_int(conf, CONF_protocol) == PROT_SSH && !conf_get_int(conf, CONF_x11_forward) && !conf_get_int(conf, CONF_agentfwd) && !conf_get_str_nthstrkey(conf, CONF_portfwd, 0)) conf_set_int(conf, CONF_ssh_simple, TRUE); if (just_test_share_exists) { if (!backvt->test_for_upstream) { fprintf(stderr, "Connection sharing not supported for connection " "type '%s'\n", backvt->name); return 1; } if (backvt->test_for_upstream(conf_get_str(conf, CONF_host), conf_get_int(conf, CONF_port), conf)) return 0; else return 1; } /* * Start up the connection. */ logctx = log_init(NULL, conf); console_provide_logctx(logctx); { const char *error; char *realhost; /* nodelay is only useful if stdin is a terminal device */ int nodelay = conf_get_int(conf, CONF_tcp_nodelay) && isatty(0); /* This is a good place for a fuzzer to fork us. */ #ifdef __AFL_HAVE_MANUAL_CONTROL __AFL_INIT(); #endif error = backend_init(backvt, NULL, &backend, conf, conf_get_str(conf, CONF_host), conf_get_int(conf, CONF_port), &realhost, nodelay, conf_get_int(conf, CONF_tcp_keepalives)); if (error) { fprintf(stderr, "Unable to open connection:\n%s\n", error); return 1; } backend_provide_logctx(backend, logctx); ldisc_create(conf, NULL, backend, NULL); sfree(realhost); } /* * Set up the initial console mode. We don't care if this call * fails, because we know we aren't necessarily running in a * console. */ local_tty = (tcgetattr(STDIN_FILENO, &orig_termios) == 0); atexit(cleanup_termios); frontend_echoedit_update(NULL, 1, 1); sending = FALSE; now = GETTICKCOUNT(); while (1) { fd_set rset, wset, xset; int maxfd; int rwx; int ret; unsigned long next; FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&xset); maxfd = 0; FD_SET_MAX(signalpipe[0], maxfd, rset); if (!sending && backend_connected(backend) && backend_sendok(backend) && backend_sendbuffer(backend) < MAX_STDIN_BACKLOG) { /* If we're OK to send, then try to read from stdin. */ FD_SET_MAX(STDIN_FILENO, maxfd, rset); } if (bufchain_size(&stdout_data) > 0) { /* If we have data for stdout, try to write to stdout. */ FD_SET_MAX(STDOUT_FILENO, maxfd, wset); } if (bufchain_size(&stderr_data) > 0) { /* If we have data for stderr, try to write to stderr. */ FD_SET_MAX(STDERR_FILENO, maxfd, wset); } /* Count the currently active fds. */ i = 0; for (fd = first_fd(&fdstate, &rwx); fd >= 0; fd = next_fd(&fdstate, &rwx)) i++; /* Expand the fdlist buffer if necessary. */ if (i > fdsize) { fdsize = i + 16; fdlist = sresize(fdlist, fdsize, int); } /* * Add all currently open fds to the select sets, and store * them in fdlist as well. */ fdcount = 0; for (fd = first_fd(&fdstate, &rwx); fd >= 0; fd = next_fd(&fdstate, &rwx)) { fdlist[fdcount++] = fd; if (rwx & 1) FD_SET_MAX(fd, maxfd, rset); if (rwx & 2) FD_SET_MAX(fd, maxfd, wset); if (rwx & 4) FD_SET_MAX(fd, maxfd, xset); } if (toplevel_callback_pending()) { struct timeval tv; tv.tv_sec = 0; tv.tv_usec = 0; ret = select(maxfd, &rset, &wset, &xset, &tv); } else if (run_timers(now, &next)) { do { unsigned long then; long ticks; struct timeval tv; then = now; now = GETTICKCOUNT(); if (now - then > next - then) ticks = 0; else ticks = next - now; tv.tv_sec = ticks / 1000; tv.tv_usec = ticks % 1000 * 1000; ret = select(maxfd, &rset, &wset, &xset, &tv); if (ret == 0) now = next; else now = GETTICKCOUNT(); } while (ret < 0 && errno == EINTR); } else { ret = select(maxfd, &rset, &wset, &xset, NULL); } if (ret < 0 && errno == EINTR) continue; if (ret < 0) { perror("select"); exit(1); } for (i = 0; i < fdcount; i++) { fd = fdlist[i]; /* * We must process exceptional notifications before * ordinary readability ones, or we may go straight * past the urgent marker. */ if (FD_ISSET(fd, &xset)) select_result(fd, 4); if (FD_ISSET(fd, &rset)) select_result(fd, 1); if (FD_ISSET(fd, &wset)) select_result(fd, 2); } if (FD_ISSET(signalpipe[0], &rset)) { char c[1]; struct winsize size; if (read(signalpipe[0], c, 1) <= 0) /* ignore error */; /* ignore its value; it'll be `x' */ if (ioctl(STDIN_FILENO, TIOCGWINSZ, (void *)&size) >= 0) backend_size(backend, size.ws_col, size.ws_row); } if (FD_ISSET(STDIN_FILENO, &rset)) { char buf[4096]; int ret; if (backend_connected(backend)) { ret = read(STDIN_FILENO, buf, sizeof(buf)); if (ret < 0) { perror("stdin: read"); exit(1); } else if (ret == 0) { backend_special(backend, SS_EOF, 0); sending = FALSE; /* send nothing further after this */ } else { if (local_tty) from_tty(buf, ret); else backend_send(backend, buf, ret); } } } if (FD_ISSET(STDOUT_FILENO, &wset)) { backend_unthrottle(backend, try_output(FALSE)); } if (FD_ISSET(STDERR_FILENO, &wset)) { backend_unthrottle(backend, try_output(TRUE)); } run_toplevel_callbacks(); if (!backend_connected(backend) && bufchain_size(&stdout_data) == 0 && bufchain_size(&stderr_data) == 0) break; /* we closed the connection */ } exitcode = backend_exitcode(backend); if (exitcode < 0) { fprintf(stderr, "Remote process exit code unavailable\n"); exitcode = 1; /* this is an error condition */ } cleanup_exit(exitcode); return exitcode; /* shouldn't happen, but placates gcc */ }