diff options
Diffstat (limited to 'UNIX/UXPTY.C')
| -rw-r--r-- | UNIX/UXPTY.C | 1612 |
1 files changed, 0 insertions, 1612 deletions
diff --git a/UNIX/UXPTY.C b/UNIX/UXPTY.C deleted file mode 100644 index bfd0de57..00000000 --- a/UNIX/UXPTY.C +++ /dev/null @@ -1,1612 +0,0 @@ -/* - * Pseudo-tty backend for pterm. - */ - -#define _GNU_SOURCE - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include <signal.h> -#include <assert.h> -#include <fcntl.h> -#include <termios.h> -#include <grp.h> -#include <utmp.h> -#include <pwd.h> -#include <time.h> -#include <sys/types.h> -#include <sys/stat.h> -#include <sys/wait.h> -#include <sys/ioctl.h> -#include <errno.h> -#include <termios.h> - -#include "putty.h" -#include "ssh.h" -#include "sshserver.h" /* to check the prototypes of server-needed things */ -#include "tree234.h" - -#ifndef OMIT_UTMP -#include <utmpx.h> -#endif - -/* updwtmpx() needs the name of the wtmp file. Try to find it. */ -#ifndef WTMPX_FILE -#ifdef _PATH_WTMPX -#define WTMPX_FILE _PATH_WTMPX -#else -#define WTMPX_FILE "/var/log/wtmpx" -#endif -#endif - -#ifndef LASTLOG_FILE -#ifdef _PATH_LASTLOG -#define LASTLOG_FILE _PATH_LASTLOG -#else -#define LASTLOG_FILE "/var/log/lastlog" -#endif -#endif - -/* - * Set up a default for vaguely sane systems. The idea is that if - * OMIT_UTMP is not defined, then at least one of the symbols which - * enable particular forms of utmp processing should be, if only so - * that a link error can warn you that you should have defined - * OMIT_UTMP if you didn't want any. Currently HAVE_PUTUTLINE is - * the only such symbol. - */ -#ifndef OMIT_UTMP -#if !defined HAVE_PUTUTLINE -#define HAVE_PUTUTLINE -#endif -#endif - -typedef struct Pty Pty; - -/* - * The pty_signal_pipe, along with the SIGCHLD handler, must be - * process-global rather than session-specific. - */ -static int pty_signal_pipe[2] = { -1, -1 }; /* obviously bogus initial val */ - -typedef struct PtyFd { - int fd; - Pty *pty; -} PtyFd; - -struct Pty { - Conf *conf; - - int master_fd, slave_fd; - int pipefds[6]; - PtyFd fds[3]; - int master_i, master_o, master_e; - - Seat *seat; - char name[FILENAME_MAX]; - pid_t child_pid; - int term_width, term_height; - bool child_dead, finished; - int exit_code; - bufchain output_data; - bool pending_eof; - Backend backend; -}; - -/* - * We store all the (active) PtyFd structures in a tree sorted by fd, - * so that when we get an uxsel notification we know which backend - * instance is the owner of the pty that caused it, and then we can - * find out which fd is the relevant one too. - */ -static int ptyfd_compare(void *av, void *bv) -{ - PtyFd *a = (PtyFd *)av; - PtyFd *b = (PtyFd *)bv; - - if (a->fd < b->fd) - return -1; - else if (a->fd > b->fd) - return +1; - return 0; -} - -static int ptyfd_find(void *av, void *bv) -{ - int a = *(int *)av; - PtyFd *b = (PtyFd *)bv; - - if (a < b->fd) - return -1; - else if (a > b->fd) - return +1; - return 0; -} - -static tree234 *ptyfds = NULL; - -/* - * We also have a tree of Pty structures themselves, sorted by child - * pid, so that when we wait() in response to the signal we know which - * backend instance is the owner of the process that caused the - * signal. - */ -static int pty_compare_by_pid(void *av, void *bv) -{ - Pty *a = (Pty *)av; - Pty *b = (Pty *)bv; - - if (a->child_pid < b->child_pid) - return -1; - else if (a->child_pid > b->child_pid) - return +1; - return 0; -} - -static int pty_find_by_pid(void *av, void *bv) -{ - pid_t a = *(pid_t *)av; - Pty *b = (Pty *)bv; - - if (a < b->child_pid) - return -1; - else if (a > b->child_pid) - return +1; - return 0; -} - -static tree234 *ptys_by_pid = NULL; - -/* - * If we are using pty_pre_init(), it will need to have already - * allocated a pty structure, which we must then return from - * pty_init() rather than allocating a new one. Here we store that - * structure between allocation and use. - * - * Note that although most of this module is entirely capable of - * handling multiple ptys in a single process, pty_pre_init() is - * fundamentally _dependent_ on there being at most one pty per - * process, so the normal static-data constraints don't apply. - * - * Likewise, since utmp is only used via pty_pre_init, it too must - * be single-instance, so we can declare utmp-related variables - * here. - */ -static Pty *single_pty = NULL; - -#ifndef OMIT_UTMP -static pid_t pty_utmp_helper_pid = -1; -static int pty_utmp_helper_pipe = -1; -static bool pty_stamped_utmp; -static struct utmpx utmp_entry; -#endif - -/* - * pty_argv is a grievous hack to allow a proper argv to be passed - * through from the Unix command line. Again, it doesn't really - * make sense outside a one-pty-per-process setup. - */ -char **pty_argv; - -char *pty_osx_envrestore_prefix; - -static void pty_close(Pty *pty); -static void pty_try_write(Pty *pty); - -#ifndef OMIT_UTMP -static void setup_utmp(char *ttyname, char *location) -{ -#ifdef HAVE_LASTLOG - struct lastlog lastlog_entry; - FILE *lastlog; -#endif - struct passwd *pw; - struct timeval tv; - - pw = getpwuid(getuid()); - if (!pw) - return; /* can't stamp utmp if we don't have a username */ - memset(&utmp_entry, 0, sizeof(utmp_entry)); - utmp_entry.ut_type = USER_PROCESS; - utmp_entry.ut_pid = getpid(); -#if __GNUC__ >= 8 -# pragma GCC diagnostic push -# pragma GCC diagnostic ignored "-Wstringop-truncation" -#endif // __GNUC__ >= 8 - strncpy(utmp_entry.ut_line, ttyname+5, lenof(utmp_entry.ut_line)); - strncpy(utmp_entry.ut_id, ttyname+8, lenof(utmp_entry.ut_id)); - strncpy(utmp_entry.ut_user, pw->pw_name, lenof(utmp_entry.ut_user)); - strncpy(utmp_entry.ut_host, location, lenof(utmp_entry.ut_host)); -#if __GNUC__ >= 8 -# pragma GCC diagnostic pop -#endif // __GNUC__ >= 8 - /* - * Apparently there are some architectures where (struct - * utmpx).ut_tv is not essentially struct timeval (e.g. Linux - * amd64). Hence the temporary. - */ - gettimeofday(&tv, NULL); - utmp_entry.ut_tv.tv_sec = tv.tv_sec; - utmp_entry.ut_tv.tv_usec = tv.tv_usec; - - setutxent(); - pututxline(&utmp_entry); - endutxent(); - - updwtmpx(WTMPX_FILE, &utmp_entry); - -#ifdef HAVE_LASTLOG - memset(&lastlog_entry, 0, sizeof(lastlog_entry)); - strncpy(lastlog_entry.ll_line, ttyname+5, lenof(lastlog_entry.ll_line)); - strncpy(lastlog_entry.ll_host, location, lenof(lastlog_entry.ll_host)); - time(&lastlog_entry.ll_time); - if ((lastlog = fopen(LASTLOG_FILE, "r+")) != NULL) { - fseek(lastlog, sizeof(lastlog_entry) * getuid(), SEEK_SET); - fwrite(&lastlog_entry, 1, sizeof(lastlog_entry), lastlog); - fclose(lastlog); - } -#endif - - pty_stamped_utmp = true; - -} - -static void cleanup_utmp(void) -{ - struct timeval tv; - - if (!pty_stamped_utmp) - return; - - utmp_entry.ut_type = DEAD_PROCESS; - memset(utmp_entry.ut_user, 0, lenof(utmp_entry.ut_user)); - gettimeofday(&tv, NULL); - utmp_entry.ut_tv.tv_sec = tv.tv_sec; - utmp_entry.ut_tv.tv_usec = tv.tv_usec; - - updwtmpx(WTMPX_FILE, &utmp_entry); - - memset(utmp_entry.ut_line, 0, lenof(utmp_entry.ut_line)); - utmp_entry.ut_tv.tv_sec = 0; - utmp_entry.ut_tv.tv_usec = 0; - - setutxent(); - pututxline(&utmp_entry); - endutxent(); - - pty_stamped_utmp = false; /* ensure we never double-cleanup */ -} -#endif - -static void sigchld_handler(int signum) -{ - if (write(pty_signal_pipe[1], "x", 1) <= 0) - /* not much we can do about it */; -} - -static void pty_setup_sigchld_handler(void) -{ - static bool setup = false; - if (!setup) { - putty_signal(SIGCHLD, sigchld_handler); - setup = true; - } -} - -#ifndef OMIT_UTMP -static void fatal_sig_handler(int signum) -{ - putty_signal(signum, SIG_DFL); - cleanup_utmp(); - raise(signum); -} -#endif - -static int pty_open_slave(Pty *pty) -{ - if (pty->slave_fd < 0) { - pty->slave_fd = open(pty->name, O_RDWR); - cloexec(pty->slave_fd); - } - - return pty->slave_fd; -} - -static void pty_open_master(Pty *pty) -{ -#ifdef BSD_PTYS - const char chars1[] = "pqrstuvwxyz"; - const char chars2[] = "0123456789abcdef"; - const char *p1, *p2; - char master_name[20]; - struct group *gp; - - for (p1 = chars1; *p1; p1++) - for (p2 = chars2; *p2; p2++) { - sprintf(master_name, "/dev/pty%c%c", *p1, *p2); - pty->master_fd = open(master_name, O_RDWR); - if (pty->master_fd >= 0) { - if (geteuid() == 0 || - access(master_name, R_OK | W_OK) == 0) { - /* - * We must also check at this point that we are - * able to open the slave side of the pty. We - * wouldn't want to allocate the wrong master, - * get all the way down to forking, and _then_ - * find we're unable to open the slave. - */ - strcpy(pty->name, master_name); - pty->name[5] = 't'; /* /dev/ptyXX -> /dev/ttyXX */ - - cloexec(pty->master_fd); - - if (pty_open_slave(pty) >= 0 && - access(pty->name, R_OK | W_OK) == 0) - goto got_one; - if (pty->slave_fd > 0) - close(pty->slave_fd); - pty->slave_fd = -1; - } - close(pty->master_fd); - } - } - - /* If we get here, we couldn't get a tty at all. */ - fprintf(stderr, "pterm: unable to open a pseudo-terminal device\n"); - exit(1); - - got_one: - - /* We need to chown/chmod the /dev/ttyXX device. */ - gp = getgrnam("tty"); - chown(pty->name, getuid(), gp ? gp->gr_gid : -1); - chmod(pty->name, 0600); -#else - - const int flags = O_RDWR -#ifdef O_NOCTTY - | O_NOCTTY -#endif - ; - -#ifdef HAVE_POSIX_OPENPT -#ifdef SET_NONBLOCK_VIA_OPENPT - /* - * OS X, as of 10.10 at least, doesn't permit me to set O_NONBLOCK - * on pty master fds via the usual fcntl mechanism. Fortunately, - * it does let me work around this by adding O_NONBLOCK to the - * posix_openpt flags parameter, which isn't a documented use of - * the API but seems to work. So we'll do that for now. - */ - pty->master_fd = posix_openpt(flags | O_NONBLOCK); -#else - pty->master_fd = posix_openpt(flags); -#endif - - if (pty->master_fd < 0) { - perror("posix_openpt"); - exit(1); - } -#else - pty->master_fd = open("/dev/ptmx", flags); - - if (pty->master_fd < 0) { - perror("/dev/ptmx: open"); - exit(1); - } -#endif - - if (grantpt(pty->master_fd) < 0) { - perror("grantpt"); - exit(1); - } - - if (unlockpt(pty->master_fd) < 0) { - perror("unlockpt"); - exit(1); - } - - cloexec(pty->master_fd); - - pty->name[FILENAME_MAX-1] = '\0'; - strncpy(pty->name, ptsname(pty->master_fd), FILENAME_MAX-1); -#endif - -#ifndef SET_NONBLOCK_VIA_OPENPT - nonblock(pty->master_fd); -#endif -} - -static Pty *new_pty_struct(void) -{ - Pty *pty = snew(Pty); - pty->conf = NULL; - pty->pending_eof = false; - bufchain_init(&pty->output_data); - return pty; -} - -/* - * Pre-initialisation. This is here to get around the fact that GTK - * doesn't like being run in setuid/setgid programs (probably - * sensibly). So before we initialise GTK - and therefore before we - * even process the command line - we check to see if we're running - * set[ug]id. If so, we open our pty master _now_, chown it as - * necessary, and drop privileges. We can always close it again - * later. If we're potentially going to be doing utmp as well, we - * also fork off a utmp helper process and communicate with it by - * means of a pipe; the utmp helper will keep privileges in order - * to clean up utmp when we exit (i.e. when its end of our pipe - * closes). - */ -void pty_pre_init(void) -{ -#ifndef NO_PTY_PRE_INIT - - Pty *pty; - -#ifndef OMIT_UTMP - pid_t pid; - int pipefd[2]; -#endif - - pty = single_pty = new_pty_struct(); - - /* set the child signal handler straight away; it needs to be set - * before we ever fork. */ - pty_setup_sigchld_handler(); - pty->master_fd = pty->slave_fd = -1; -#ifndef OMIT_UTMP - pty_stamped_utmp = false; -#endif - - if (geteuid() != getuid() || getegid() != getgid()) { - pty_open_master(pty); - -#ifndef OMIT_UTMP - /* - * Fork off the utmp helper. - */ - if (pipe(pipefd) < 0) { - perror("pterm: pipe"); - exit(1); - } - cloexec(pipefd[0]); - cloexec(pipefd[1]); - pid = fork(); - if (pid < 0) { - perror("pterm: fork"); - exit(1); - } else if (pid == 0) { - char display[128], buffer[128]; - int dlen, ret; - - close(pipefd[1]); - /* - * Now sit here until we receive a display name from the - * other end of the pipe, and then stamp utmp. Unstamp utmp - * again, and exit, when the pipe closes. - */ - - dlen = 0; - while (1) { - - ret = read(pipefd[0], buffer, lenof(buffer)); - if (ret <= 0) { - cleanup_utmp(); - _exit(0); - } else if (!pty_stamped_utmp) { - if (dlen < lenof(display)) - memcpy(display+dlen, buffer, - min(ret, lenof(display)-dlen)); - if (buffer[ret-1] == '\0') { - /* - * Now we have a display name. NUL-terminate - * it, and stamp utmp. - */ - display[lenof(display)-1] = '\0'; - /* - * Trap as many fatal signals as we can in the - * hope of having the best possible chance to - * clean up utmp before termination. We are - * unfortunately unprotected against SIGKILL, - * but that's life. - */ - putty_signal(SIGHUP, fatal_sig_handler); - putty_signal(SIGINT, fatal_sig_handler); - putty_signal(SIGQUIT, fatal_sig_handler); - putty_signal(SIGILL, fatal_sig_handler); - putty_signal(SIGABRT, fatal_sig_handler); - putty_signal(SIGFPE, fatal_sig_handler); - putty_signal(SIGPIPE, fatal_sig_handler); - putty_signal(SIGALRM, fatal_sig_handler); - putty_signal(SIGTERM, fatal_sig_handler); - putty_signal(SIGSEGV, fatal_sig_handler); - putty_signal(SIGUSR1, fatal_sig_handler); - putty_signal(SIGUSR2, fatal_sig_handler); -#ifdef SIGBUS - putty_signal(SIGBUS, fatal_sig_handler); -#endif -#ifdef SIGPOLL - putty_signal(SIGPOLL, fatal_sig_handler); -#endif -#ifdef SIGPROF - putty_signal(SIGPROF, fatal_sig_handler); -#endif -#ifdef SIGSYS - putty_signal(SIGSYS, fatal_sig_handler); -#endif -#ifdef SIGTRAP - putty_signal(SIGTRAP, fatal_sig_handler); -#endif -#ifdef SIGVTALRM - putty_signal(SIGVTALRM, fatal_sig_handler); -#endif -#ifdef SIGXCPU - putty_signal(SIGXCPU, fatal_sig_handler); -#endif -#ifdef SIGXFSZ - putty_signal(SIGXFSZ, fatal_sig_handler); -#endif -#ifdef SIGIO - putty_signal(SIGIO, fatal_sig_handler); -#endif - setup_utmp(pty->name, display); - } - } - } - } else { - close(pipefd[0]); - pty_utmp_helper_pid = pid; - pty_utmp_helper_pipe = pipefd[1]; - } -#endif - } - - /* Drop privs. */ - { -#ifndef HAVE_NO_SETRESUID - int gid = getgid(), uid = getuid(); - int setresgid(gid_t, gid_t, gid_t); - int setresuid(uid_t, uid_t, uid_t); - if (setresgid(gid, gid, gid) < 0) { - perror("setresgid"); - exit(1); - } - if (setresuid(uid, uid, uid) < 0) { - perror("setresuid"); - exit(1); - } -#else - if (setgid(getgid()) < 0) { - perror("setgid"); - exit(1); - } - if (setuid(getuid()) < 0) { - perror("setuid"); - exit(1); - } -#endif - } - -#endif /* NO_PTY_PRE_INIT */ - -} - -static void pty_try_wait(void); - -static void pty_real_select_result(Pty *pty, int fd, int event, int status) -{ - char buf[4096]; - int ret; - bool finished = false; - - if (event < 0) { - /* - * We've been called because our child process did - * something. `status' tells us what. - */ - if ((WIFEXITED(status) || WIFSIGNALED(status))) { - /* - * The primary child process died. - */ - pty->child_dead = true; - del234(ptys_by_pid, pty); - pty->exit_code = status; - - /* - * If this is an ordinary pty session, this is also the - * moment to terminate the whole backend. - * - * We _could_ instead keep the terminal open for remaining - * subprocesses to output to, but conventional wisdom - * seems to feel that that's the Wrong Thing for an - * xterm-alike, so we bail out now (though we don't - * necessarily _close_ the window, depending on the state - * of Close On Exit). This would be easy enough to change - * or make configurable if necessary. - */ - if (pty->master_fd >= 0) - finished = true; - } - } else { - if (event == SELECT_R) { - bool is_stdout = (fd == pty->master_o); - - ret = read(fd, buf, sizeof(buf)); - - /* - * Treat EIO on a pty master as equivalent to EOF (because - * that's how the kernel seems to report the event where - * the last process connected to the other end of the pty - * went away). - */ - if (fd == pty->master_fd && ret < 0 && errno == EIO) - ret = 0; - - if (ret == 0) { - /* - * EOF on this input fd, so to begin with, we may as - * well close it, and remove all references to it in - * the pty's fd fields. - */ - uxsel_del(fd); - close(fd); - if (pty->master_fd == fd) - pty->master_fd = -1; - if (pty->master_o == fd) - pty->master_o = -1; - if (pty->master_e == fd) - pty->master_e = -1; - - if (is_stdout) { - /* - * We assume a clean exit if the pty (or stdout - * pipe) has closed, but the actual child process - * hasn't. The only way I can imagine this - * happening is if it detaches itself from the pty - * and goes daemonic - in which case the expected - * usage model would precisely _not_ be for the - * pterm window to hang around! - */ - finished = true; - pty_try_wait(); /* one last effort to collect exit code */ - if (!pty->child_dead) - pty->exit_code = 0; - } - } else if (ret < 0) { - perror("read pty master"); - exit(1); - } else if (ret > 0) { - seat_output(pty->seat, !is_stdout, buf, ret); - } - } else if (event == SELECT_W) { - /* - * Attempt to send data down the pty. - */ - pty_try_write(pty); - } - } - - if (finished && !pty->finished) { - int close_on_exit; - int i; - - for (i = 0; i < 3; i++) - if (pty->fds[i].fd >= 0) - uxsel_del(pty->fds[i].fd); - - pty_close(pty); - - pty->finished = true; - - /* - * This is a slight layering-violation sort of hack: only - * if we're not closing on exit (COE is set to Never, or to - * Only On Clean and it wasn't a clean exit) do we output a - * `terminated' message. - */ - close_on_exit = conf_get_int(pty->conf, CONF_close_on_exit); - if (close_on_exit == FORCE_OFF || - (close_on_exit == AUTO && pty->exit_code != 0)) { - char *message; - if (WIFEXITED(pty->exit_code)) { - message = dupprintf( - "\r\n[pterm: process terminated with exit code %d]\r\n", - WEXITSTATUS(pty->exit_code)); - } else if (WIFSIGNALED(pty->exit_code)) { -#ifdef HAVE_NO_STRSIGNAL - message = dupprintf( - "\r\n[pterm: process terminated on signal %d]\r\n", - WTERMSIG(pty->exit_code)); -#else - message = dupprintf( - "\r\n[pterm: process terminated on signal %d (%s)]\r\n", - WTERMSIG(pty->exit_code), - strsignal(WTERMSIG(pty->exit_code))); -#endif - } else { - /* _Shouldn't_ happen, but if it does, a vague message - * is better than no message at all */ - message = dupprintf("\r\n[pterm: process terminated]\r\n"); - } - seat_stdout_pl(pty->seat, ptrlen_from_asciz(message)); - sfree(message); - } - - seat_eof(pty->seat); - seat_notify_remote_exit(pty->seat); - } -} - -static void pty_try_wait(void) -{ - Pty *pty; - pid_t pid; - int status; - - do { - pid = waitpid(-1, &status, WNOHANG); - - pty = find234(ptys_by_pid, &pid, pty_find_by_pid); - - if (pty) - pty_real_select_result(pty, -1, -1, status); - } while (pid > 0); -} - -void pty_select_result(int fd, int event) -{ - if (fd == pty_signal_pipe[0]) { - char c[1]; - - if (read(pty_signal_pipe[0], c, 1) <= 0) - /* ignore error */; - /* ignore its value; it'll be `x' */ - - pty_try_wait(); - } else { - PtyFd *ptyfd = find234(ptyfds, &fd, ptyfd_find); - - if (ptyfd) - pty_real_select_result(ptyfd->pty, fd, event, 0); - } -} - -static void pty_uxsel_setup_fd(Pty *pty, int fd) -{ - int rwx = 0; - - if (fd < 0) - return; - - /* read from standard output and standard error pipes */ - if (pty->master_o == fd || pty->master_e == fd) - rwx |= SELECT_R; - /* write to standard input pipe if we have any data */ - if (pty->master_i == fd && bufchain_size(&pty->output_data)) - rwx |= SELECT_W; - - uxsel_set(fd, rwx, pty_select_result); -} - -static void pty_uxsel_setup(Pty *pty) -{ - /* - * We potentially have three separate fds here, but on the other - * hand, some of them might be the same (if they're a pty master). - * So we can't just call uxsel_set(master_o, SELECT_R) and then - * uxsel_set(master_i, SELECT_W), without the latter potentially - * undoing the work of the former if master_o == master_i. - * - * Instead, here we call a single uxsel on each one of these fds - * (if it exists at all), and for each one, check it against all - * three to see which bits to set. - */ - pty_uxsel_setup_fd(pty, pty->master_o); - pty_uxsel_setup_fd(pty, pty->master_e); - pty_uxsel_setup_fd(pty, pty->master_i); - - /* - * In principle this only needs calling once for all pty - * backend instances, but it's simplest just to call it every - * time; uxsel won't mind. - */ - uxsel_set(pty_signal_pipe[0], SELECT_R, pty_select_result); -} - -static void copy_ttymodes_into_termios( - struct termios *attrs, struct ssh_ttymodes modes) -{ -#define TTYMODE_CHAR(name, ssh_opcode, cc_index) { \ - if (modes.have_mode[ssh_opcode]) { \ - unsigned value = modes.mode_val[ssh_opcode]; \ - /* normalise wire value of 255 to local _POSIX_VDISABLE */ \ - attrs->c_cc[cc_index] = (value == 255 ? \ - _POSIX_VDISABLE : value); \ - } \ - } - -#define TTYMODE_FLAG(flagval, ssh_opcode, field, flagmask) { \ - if (modes.have_mode[ssh_opcode]) { \ - attrs->c_##field##flag &= ~flagmask; \ - if (modes.mode_val[ssh_opcode]) \ - attrs->c_##field##flag |= flagval; \ - } \ - } - -#define TTYMODES_LOCAL_ONLY /* omit any that this platform doesn't know */ -#include "sshttymodes.h" - -#undef TTYMODES_LOCAL_ONLY -#undef TTYMODE_CHAR -#undef TTYMODE_FLAG - - if (modes.have_mode[TTYMODE_ISPEED]) - cfsetispeed(attrs, modes.mode_val[TTYMODE_ISPEED]); - if (modes.have_mode[TTYMODE_OSPEED]) - cfsetospeed(attrs, modes.mode_val[TTYMODE_OSPEED]); -} - -/* - * The main setup function for the pty back end. This doesn't match - * the signature of backend_init(), partly because it has to be able - * to take extra arguments such as an argv array, and also because - * once we're changing the type signature _anyway_ we can discard the - * stuff that's not really applicable to this backend like host names - * and port numbers. - */ -Backend *pty_backend_create( - Seat *seat, LogContext *logctx, Conf *conf, char **argv, const char *cmd, - struct ssh_ttymodes ttymodes, bool pipes_instead, const char *dir, - const char *const *env_vars_to_unset) -{ - int slavefd; - pid_t pid, pgrp; -#ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */ - bool got_windowid; - long windowid; -#endif - Pty *pty; - int i; - - /* No local authentication phase in this protocol */ - seat_set_trust_status(seat, false); - - if (single_pty) { - pty = single_pty; - assert(pty->conf == NULL); - } else { - pty = new_pty_struct(); - pty->master_fd = pty->slave_fd = -1; -#ifndef OMIT_UTMP - pty_stamped_utmp = false; -#endif - } - for (i = 0; i < 6; i++) - pty->pipefds[i] = -1; - for (i = 0; i < 3; i++) { - pty->fds[i].fd = -1; - pty->fds[i].pty = pty; - } - - if (pty_signal_pipe[0] < 0) { - if (pipe(pty_signal_pipe) < 0) { - perror("pipe"); - exit(1); - } - cloexec(pty_signal_pipe[0]); - cloexec(pty_signal_pipe[1]); - } - - pty->seat = seat; - pty->backend.vt = &pty_backend; - - pty->conf = conf_copy(conf); - pty->term_width = conf_get_int(conf, CONF_width); - pty->term_height = conf_get_int(conf, CONF_height); - - if (!ptyfds) - ptyfds = newtree234(ptyfd_compare); - - if (pipes_instead) { - if (pty->master_fd >= 0) { - /* If somehow we've got a pty master already and don't - * need it, throw it away! */ - close(pty->master_fd); -#ifndef OMIT_UTMP - if (pty_utmp_helper_pipe >= 0) { - close(pty_utmp_helper_pipe); /* don't need this either */ - pty_utmp_helper_pipe = -1; - } -#endif - } - - - for (i = 0; i < 6; i += 2) { - if (pipe(pty->pipefds + i) < 0) { - backend_free(&pty->backend); - return NULL; - } - } - - pty->fds[0].fd = pty->master_i = pty->pipefds[1]; - pty->fds[1].fd = pty->master_o = pty->pipefds[2]; - pty->fds[2].fd = pty->master_e = pty->pipefds[4]; - - add234(ptyfds, &pty->fds[0]); - add234(ptyfds, &pty->fds[1]); - add234(ptyfds, &pty->fds[2]); - } else { - if (pty->master_fd < 0) - pty_open_master(pty); - -#ifndef OMIT_UTMP - /* - * Stamp utmp (that is, tell the utmp helper process to do so), - * or not. - */ - if (pty_utmp_helper_pipe >= 0) { /* if it's < 0, we can't anyway */ - if (!conf_get_bool(conf, CONF_stamp_utmp)) { - /* We're not stamping utmp, so just let the child - * process die that was waiting to unstamp it later. */ - close(pty_utmp_helper_pipe); - pty_utmp_helper_pipe = -1; - } else { - const char *location = seat_get_x_display(pty->seat); - int len = strlen(location)+1, pos = 0; /* +1 to include NUL */ - while (pos < len) { - int ret = write(pty_utmp_helper_pipe, - location + pos, len - pos); - if (ret < 0) { - perror("pterm: writing to utmp helper process"); - close(pty_utmp_helper_pipe); /* arrgh, just give up */ - pty_utmp_helper_pipe = -1; - break; - } - pos += ret; - } - } - } -#endif - - pty->master_i = pty->master_fd; - pty->master_o = pty->master_fd; - pty->master_e = -1; - - pty->fds[0].fd = pty->master_fd; - add234(ptyfds, &pty->fds[0]); - } - -#ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */ - got_windowid = seat_get_windowid(pty->seat, &windowid); -#endif - - /* - * Set up the signal handler to catch SIGCHLD, if pty_pre_init - * didn't already do it. - */ - pty_setup_sigchld_handler(); - - /* - * Fork and execute the command. - */ - pid = fork(); - if (pid < 0) { - perror("fork"); - exit(1); - } - - if (pid == 0) { - struct termios attrs; - - /* - * We are the child. - */ - - if (pty_osx_envrestore_prefix) { - int plen = strlen(pty_osx_envrestore_prefix); - extern char **environ; - char **ep; - - restart_osx_env_restore: - for (ep = environ; *ep; ep++) { - char *e = *ep; - - if (!strncmp(e, pty_osx_envrestore_prefix, plen)) { - bool unset = (e[plen] == 'u'); - char *pname = dupprintf("%.*s", (int)strcspn(e, "="), e); - char *name = pname + plen + 1; - char *value = e + strcspn(e, "="); - if (*value) value++; - value = dupstr(value); - if (unset) - unsetenv(name); - else - setenv(name, value, 1); - unsetenv(pname); - sfree(pname); - sfree(value); - goto restart_osx_env_restore; - } - } - } - - pgrp = getpid(); - - if (pipes_instead) { - int i; - dup2(pty->pipefds[0], 0); - dup2(pty->pipefds[3], 1); - dup2(pty->pipefds[5], 2); - for (i = 0; i < 6; i++) - close(pty->pipefds[i]); - - setsid(); - } else { - slavefd = pty_open_slave(pty); - if (slavefd < 0) { - perror("slave pty: open"); - _exit(1); - } - - close(pty->master_fd); - noncloexec(slavefd); - dup2(slavefd, 0); - dup2(slavefd, 1); - dup2(slavefd, 2); - close(slavefd); - setsid(); -#ifdef TIOCSCTTY - ioctl(0, TIOCSCTTY, 1); -#endif - tcsetpgrp(0, pgrp); - - /* - * Set up configuration-dependent termios settings on the new - * pty. Linux would have let us do this on the pty master - * before we forked, but that fails on OS X, so we do it here - * instead. - */ - if (tcgetattr(0, &attrs) == 0) { - /* - * Set the backspace character to be whichever of ^H and - * ^? is specified by bksp_is_delete. - */ - attrs.c_cc[VERASE] = conf_get_bool(conf, CONF_bksp_is_delete) - ? '\177' : '\010'; - - /* - * Set the IUTF8 bit iff the character set is UTF-8. - */ -#ifdef IUTF8 - if (seat_is_utf8(seat)) - attrs.c_iflag |= IUTF8; - else - attrs.c_iflag &= ~IUTF8; -#endif - - copy_ttymodes_into_termios(&attrs, ttymodes); - - tcsetattr(0, TCSANOW, &attrs); - } - } - - setpgid(pgrp, pgrp); - if (!pipes_instead) { - int ptyfd = open(pty->name, O_WRONLY, 0); - if (ptyfd >= 0) - close(ptyfd); - } - setpgid(pgrp, pgrp); - - if (env_vars_to_unset) - for (const char *const *p = env_vars_to_unset; *p; p++) - unsetenv(*p); - - if (!pipes_instead) { - char *term_env_var = dupprintf("TERM=%s", - conf_get_str(conf, CONF_termtype)); - putenv(term_env_var); - /* We mustn't free term_env_var, as putenv links it into the - * environment in place. - */ - } -#ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */ - if (got_windowid) { - char *windowid_env_var = dupprintf("WINDOWID=%ld", windowid); - putenv(windowid_env_var); - /* We mustn't free windowid_env_var, as putenv links it into the - * environment in place. - */ - } - { - /* - * In case we were invoked with a --display argument that - * doesn't match DISPLAY in our actual environment, we - * should set DISPLAY for processes running inside the - * terminal to match the display the terminal itself is - * on. - */ - const char *x_display = seat_get_x_display(pty->seat); - if (x_display) { - char *x_display_env_var = dupprintf("DISPLAY=%s", x_display); - putenv(x_display_env_var); - /* As above, we don't free this. */ - } else { - unsetenv("DISPLAY"); - } - } -#endif - { - char *key, *val; - - for (val = conf_get_str_strs(conf, CONF_environmt, NULL, &key); - val != NULL; - val = conf_get_str_strs(conf, CONF_environmt, key, &key)) { - char *varval = dupcat(key, "=", val); - putenv(varval); - /* - * We must not free varval, since putenv links it - * into the environment _in place_. Weird, but - * there we go. Memory usage will be rationalised - * as soon as we exec anyway. - */ - } - } - - if (dir) { - if (chdir(dir) < 0) { - /* Ignore the error - nothing we can sensibly do about it, - * and our existing cwd is as good a fallback as any. */ - } - } - - /* - * SIGINT, SIGQUIT and SIGPIPE may have been set to ignored by - * our parent, particularly by things like sh -c 'pterm &' and - * some window or session managers. SIGPIPE was also - * (potentially) blocked by us during startup. Reverse all - * this for our child process. - */ - putty_signal(SIGINT, SIG_DFL); - putty_signal(SIGQUIT, SIG_DFL); - putty_signal(SIGPIPE, SIG_DFL); - block_signal(SIGPIPE, false); - if (argv || cmd) { - /* - * If we were given a separated argument list, try to exec - * it. - */ - if (argv) { - execvp(argv[0], argv); - } - /* - * Otherwise, if we were given a single command string, - * try passing that to $SHELL -c. - * - * In the case of pterm, this system of fallbacks arranges - * that we can _either_ follow 'pterm -e' with a list of - * argv elements to be fed directly to exec, _or_ with a - * single argument containing a command to be parsed by a - * shell (but, in cases of doubt, the former is more - * reliable). We arrange this by setting argv to the full - * argument list, and also setting cmd to the single - * element of argv if it's a length-1 list. - * - * A quick survey of other terminal emulators' -e options - * (as of Debian squeeze) suggests that: - * - * - xterm supports both modes, more or less like this - * - gnome-terminal will only accept a one-string shell command - * - Eterm, kterm and rxvt will only accept a list of - * argv elements (as did older versions of pterm). - * - * It therefore seems important to support both usage - * modes in order to be a drop-in replacement for either - * xterm or gnome-terminal, and hence for anyone's - * plausible uses of the Debian-style alias - * 'x-terminal-emulator'. - * - * In other use cases, a caller can set only one of argv - * and cmd to get a fixed handling of the input. - */ - if (cmd) { - char *shell = getenv("SHELL"); - if (shell) - execl(shell, shell, "-c", cmd, (void *)NULL); - } - } else { - const char *shell = getenv("SHELL"); - if (!shell) - shell = "/bin/sh"; - char *shellname; - if (conf_get_bool(conf, CONF_login_shell)) { - const char *p = strrchr(shell, '/'); - shellname = snewn(2+strlen(shell), char); - p = p ? p+1 : shell; - sprintf(shellname, "-%s", p); - } else - shellname = (char *)shell; - execl(shell, shellname, (void *)NULL); - } - - /* - * If we're here, exec has gone badly foom. - */ - perror("exec"); - _exit(127); - } else { - pty->child_pid = pid; - pty->child_dead = false; - pty->finished = false; - if (pty->slave_fd > 0) - close(pty->slave_fd); - if (!ptys_by_pid) - ptys_by_pid = newtree234(pty_compare_by_pid); - if (pty->pipefds[0] >= 0) { - close(pty->pipefds[0]); - pty->pipefds[0] = -1; - } - if (pty->pipefds[3] >= 0) { - close(pty->pipefds[3]); - pty->pipefds[3] = -1; - } - if (pty->pipefds[5] >= 0) { - close(pty->pipefds[5]); - pty->pipefds[5] = -1; - } - add234(ptys_by_pid, pty); - } - - pty_uxsel_setup(pty); - - return &pty->backend; -} - -/* - * This is the pty backend's _official_ init method, for BackendVtable - * purposes. Its job is just to be an API converter, ignoring the - * irrelevant input parameters and making up auxiliary outputs. Also - * it gets the argv array from the global variable pty_argv, expecting - * that it will have been invoked by pterm. - */ -static char *pty_init(const BackendVtable *vt, Seat *seat, - Backend **backend_handle, LogContext *logctx, - Conf *conf, const char *host, int port, - char **realhost, bool nodelay, bool keepalive) -{ - const char *cmd = NULL; - struct ssh_ttymodes modes; - - memset(&modes, 0, sizeof(modes)); - - if (pty_argv && pty_argv[0] && !pty_argv[1]) - cmd = pty_argv[0]; - - assert(vt == &pty_backend); - *backend_handle = pty_backend_create( - seat, logctx, conf, pty_argv, cmd, modes, false, NULL, NULL); - *realhost = dupstr(""); - return NULL; -} - -static void pty_reconfig(Backend *be, Conf *conf) -{ - Pty *pty = container_of(be, Pty, backend); - /* - * We don't have much need to reconfigure this backend, but - * unfortunately we do need to pick up the setting of Close On - * Exit so we know whether to give a `terminated' message. - */ - conf_copy_into(pty->conf, conf); -} - -/* - * Stub routine (never called in pterm). - */ -static void pty_free(Backend *be) -{ - Pty *pty = container_of(be, Pty, backend); - int i; - - pty_close(pty); - - /* Either of these may fail `not found'. That's fine with us. */ - del234(ptys_by_pid, pty); - for (i = 0; i < 3; i++) - if (pty->fds[i].fd >= 0) - del234(ptyfds, &pty->fds[i]); - - bufchain_clear(&pty->output_data); - - conf_free(pty->conf); - pty->conf = NULL; - - if (pty == single_pty) { - /* - * Leave this structure around in case we need to Restart - * Session. - */ - } else { - sfree(pty); - } -} - -static void pty_try_write(Pty *pty) -{ - ssize_t ret; - - assert(pty->master_i >= 0); - - while (bufchain_size(&pty->output_data) > 0) { - ptrlen data = bufchain_prefix(&pty->output_data); - ret = write(pty->master_i, data.ptr, data.len); - - if (ret < 0 && (errno == EWOULDBLOCK)) { - /* - * We've sent all we can for the moment. - */ - break; - } - if (ret < 0) { - perror("write pty master"); - exit(1); - } - bufchain_consume(&pty->output_data, ret); - } - - if (pty->pending_eof && bufchain_size(&pty->output_data) == 0) { - /* This should only happen if pty->master_i is a pipe that - * doesn't alias either output fd */ - assert(pty->master_i != pty->master_o); - assert(pty->master_i != pty->master_e); - uxsel_del(pty->master_i); - close(pty->master_i); - pty->master_i = -1; - pty->pending_eof = false; - } - - pty_uxsel_setup(pty); -} - -/* - * Called to send data down the pty. - */ -static size_t pty_send(Backend *be, const char *buf, size_t len) -{ - Pty *pty = container_of(be, Pty, backend); - - if (pty->master_i < 0 || pty->pending_eof) - return 0; /* ignore all writes if fd closed */ - - bufchain_add(&pty->output_data, buf, len); - pty_try_write(pty); - - return bufchain_size(&pty->output_data); -} - -static void pty_close(Pty *pty) -{ - int i; - - if (pty->master_o >= 0) - uxsel_del(pty->master_o); - if (pty->master_e >= 0) - uxsel_del(pty->master_e); - if (pty->master_i >= 0) - uxsel_del(pty->master_i); - - if (pty->master_fd >= 0) { - close(pty->master_fd); - pty->master_fd = -1; - } - for (i = 0; i < 6; i++) { - if (pty->pipefds[i] >= 0) - close(pty->pipefds[i]); - pty->pipefds[i] = -1; - } - pty->master_i = pty->master_o = pty->master_e = -1; -#ifndef OMIT_UTMP - if (pty_utmp_helper_pipe >= 0) { - close(pty_utmp_helper_pipe); /* this causes utmp to be cleaned up */ - pty_utmp_helper_pipe = -1; - } -#endif -} - -/* - * Called to query the current socket sendability status. - */ -static size_t pty_sendbuffer(Backend *be) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - return 0; -} - -/* - * Called to set the size of the window - */ -static void pty_size(Backend *be, int width, int height) -{ - Pty *pty = container_of(be, Pty, backend); - struct winsize size; - int xpixel = 0, ypixel = 0; - - pty->term_width = width; - pty->term_height = height; - - if (pty->master_fd < 0) - return; - - seat_get_window_pixel_size(pty->seat, &xpixel, &ypixel); - - size.ws_row = (unsigned short)pty->term_height; - size.ws_col = (unsigned short)pty->term_width; - size.ws_xpixel = (unsigned short)xpixel; - size.ws_ypixel = (unsigned short)ypixel; - ioctl(pty->master_fd, TIOCSWINSZ, (void *)&size); - return; -} - -/* - * Send special codes. - */ -static void pty_special(Backend *be, SessionSpecialCode code, int arg) -{ - Pty *pty = container_of(be, Pty, backend); - - if (code == SS_BRK) { - if (pty->master_fd >= 0) - tcsendbreak(pty->master_fd, 0); - return; - } - - if (code == SS_EOF) { - if (pty->master_i >= 0 && pty->master_i != pty->master_fd) { - pty->pending_eof = true; - pty_try_write(pty); - } - return; - } - - { - int sig = -1; - - #define SIGNAL_SUB(name) if (code == SS_SIG ## name) sig = SIG ## name; - #define SIGNAL_MAIN(name, text) SIGNAL_SUB(name) - #define SIGNALS_LOCAL_ONLY - #include "sshsignals.h" - #undef SIGNAL_SUB - #undef SIGNAL_MAIN - #undef SIGNALS_LOCAL_ONLY - - if (sig != -1) { - if (!pty->child_dead) - kill(pty->child_pid, sig); - return; - } - } - - return; -} - -/* - * Return a list of the special codes that make sense in this - * protocol. - */ -static const SessionSpecial *pty_get_specials(Backend *be) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - /* - * Hmm. When I get round to having this actually usable, it - * might be quite nice to have the ability to deliver a few - * well chosen signals to the child process - SIGINT, SIGTERM, - * SIGKILL at least. - */ - return NULL; -} - -static bool pty_connected(Backend *be) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - return true; -} - -static bool pty_sendok(Backend *be) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - return true; -} - -static void pty_unthrottle(Backend *be, size_t backlog) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - /* do nothing */ -} - -static bool pty_ldisc(Backend *be, int option) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - return false; /* neither editing nor echoing */ -} - -static void pty_provide_ldisc(Backend *be, Ldisc *ldisc) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - /* This is a stub. */ -} - -static int pty_exitcode(Backend *be) -{ - Pty *pty = container_of(be, Pty, backend); - if (!pty->finished) - return -1; /* not dead yet */ - else if (WIFSIGNALED(pty->exit_code)) - return 128 + WTERMSIG(pty->exit_code); - else - return WEXITSTATUS(pty->exit_code); -} - -int pty_backend_exit_signum(Backend *be) -{ - Pty *pty = container_of(be, Pty, backend); - - if (!pty->finished || !WIFSIGNALED(pty->exit_code)) - return -1; - - return WTERMSIG(pty->exit_code); -} - -ptrlen pty_backend_exit_signame(Backend *be, char **aux_msg) -{ - *aux_msg = NULL; - - int sig = pty_backend_exit_signum(be); - if (sig < 0) - return PTRLEN_LITERAL(""); - - #define SIGNAL_SUB(s) { \ - if (sig == SIG ## s) \ - return PTRLEN_LITERAL(#s); \ - } - #define SIGNAL_MAIN(s, desc) SIGNAL_SUB(s) - #define SIGNALS_LOCAL_ONLY - #include "sshsignals.h" - #undef SIGNAL_MAIN - #undef SIGNAL_SUB - #undef SIGNALS_LOCAL_ONLY - - *aux_msg = dupprintf("untranslatable signal number %d: %s", - sig, strsignal(sig)); - return PTRLEN_LITERAL("HUP"); /* need some kind of default */ -} - -static int pty_cfg_info(Backend *be) -{ - /* Pty *pty = container_of(be, Pty, backend); */ - return 0; -} - -const BackendVtable pty_backend = { - .init = pty_init, - .free = pty_free, - .reconfig = pty_reconfig, - .send = pty_send, - .sendbuffer = pty_sendbuffer, - .size = pty_size, - .special = pty_special, - .get_specials = pty_get_specials, - .connected = pty_connected, - .exitcode = pty_exitcode, - .sendok = pty_sendok, - .ldisc_option_state = pty_ldisc, - .provide_ldisc = pty_provide_ldisc, - .unthrottle = pty_unthrottle, - .cfg_info = pty_cfg_info, - .id = "pty", - .displayname = "pty", - .protocol = -1, -}; |