+/*
+ * Pseudo-tty backend for pterm.
+ *
+ * Unlike the other backends, data for this one is not neatly
+ * encapsulated into a data structure, because it wouldn't make
+ * sense to do so - the utmp stuff has to be done before a backend
+ * is initialised, and starting a second pterm from the same
+ * process would therefore be infeasible because privileges would
+ * already have been dropped. Hence, I haven't bothered to keep the
+ * data dynamically allocated: instead, the backend handle is just
+ * a null pointer and ignored everywhere.
+ */
+
#define _XOPEN_SOURCE
#define _XOPEN_SOURCE_EXTENDED
#include <features.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
+#include <errno.h>
#include "putty.h"
#endif
int pty_master_fd;
+static void *pty_frontend;
static char pty_name[FILENAME_MAX];
static int pty_stamped_utmp = 0;
static int pty_child_pid;
static int pty_utmp_helper_pid, pty_utmp_helper_pipe;
static int pty_term_width, pty_term_height;
-static sig_atomic_t pty_child_dead;
-static int pty_exit_code;
+static volatile sig_atomic_t pty_child_dead;
+static volatile int pty_exit_code;
#ifndef OMIT_UTMP
static struct utmp utmp_entry;
#endif
static void sigchld_handler(int signum)
{
+ int save_errno = errno;
pid_t pid;
int status;
- pid = waitpid(-1, &status, WNOHANG);
- if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status))) {
- pty_exit_code = status;
- pty_child_dead = TRUE;
- }
+
+ do {
+ pid = waitpid(-1, &status, WNOHANG);
+ if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status))) {
+ pty_exit_code = status;
+ pty_child_dead = TRUE;
+ }
+ } while(pid > 0);
+ errno = save_errno;
}
static void fatal_sig_handler(int signum)
{
- signal(signum, SIG_DFL);
+ putty_signal(signum, SIG_DFL);
cleanup_utmp();
setuid(getuid());
raise(signum);
pid_t pid;
int pipefd[2];
+ /* set the child signal handler straight away; it needs to be set
+ * before we ever fork. */
+ putty_signal(SIGCHLD, sigchld_handler);
pty_master_fd = -1;
if (geteuid() != getuid() || getegid() != getgid()) {
ret = read(pipefd[0], buffer, lenof(buffer));
if (ret <= 0) {
cleanup_utmp();
- exit(0);
+ _exit(0);
} else if (!pty_stamped_utmp) {
if (dlen < lenof(display))
memcpy(display+dlen, buffer,
* unfortunately unprotected against SIGKILL,
* but that's life.
*/
- signal(SIGHUP, fatal_sig_handler);
- signal(SIGINT, fatal_sig_handler);
- signal(SIGQUIT, fatal_sig_handler);
- signal(SIGILL, fatal_sig_handler);
- signal(SIGABRT, fatal_sig_handler);
- signal(SIGFPE, fatal_sig_handler);
- signal(SIGPIPE, fatal_sig_handler);
- signal(SIGALRM, fatal_sig_handler);
- signal(SIGTERM, fatal_sig_handler);
- signal(SIGSEGV, fatal_sig_handler);
- signal(SIGUSR1, fatal_sig_handler);
- signal(SIGUSR2, fatal_sig_handler);
+ 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
- signal(SIGBUS, fatal_sig_handler);
+ putty_signal(SIGBUS, fatal_sig_handler);
#endif
#ifdef SIGPOLL
- signal(SIGPOLL, fatal_sig_handler);
+ putty_signal(SIGPOLL, fatal_sig_handler);
#endif
#ifdef SIGPROF
- signal(SIGPROF, fatal_sig_handler);
+ putty_signal(SIGPROF, fatal_sig_handler);
#endif
#ifdef SIGSYS
- signal(SIGSYS, fatal_sig_handler);
+ putty_signal(SIGSYS, fatal_sig_handler);
#endif
#ifdef SIGTRAP
- signal(SIGTRAP, fatal_sig_handler);
+ putty_signal(SIGTRAP, fatal_sig_handler);
#endif
#ifdef SIGVTALRM
- signal(SIGVTALRM, fatal_sig_handler);
+ putty_signal(SIGVTALRM, fatal_sig_handler);
#endif
#ifdef SIGXCPU
- signal(SIGXCPU, fatal_sig_handler);
+ putty_signal(SIGXCPU, fatal_sig_handler);
#endif
#ifdef SIGXFSZ
- signal(SIGXFSZ, fatal_sig_handler);
+ putty_signal(SIGXFSZ, fatal_sig_handler);
#endif
#ifdef SIGIO
- signal(SIGIO, fatal_sig_handler);
+ putty_signal(SIGIO, fatal_sig_handler);
#endif
- /* Also clean up utmp on normal exit. */
- atexit(cleanup_utmp);
setup_utmp(pty_name, display);
}
}
close(pipefd[0]);
pty_utmp_helper_pid = pid;
pty_utmp_helper_pipe = pipefd[1];
- signal(SIGCHLD, sigchld_handler);
}
#endif
* Also places the canonical host name into `realhost'. It must be
* freed by the caller.
*/
-static char *pty_init(void *frontend,
+static char *pty_init(void *frontend, void **backend_handle, Config *cfg,
char *host, int port, char **realhost, int nodelay)
{
int slavefd;
pid_t pid, pgrp;
- pty_term_width = cfg.width;
- pty_term_height = cfg.height;
+ pty_frontend = frontend;
+ *backend_handle = NULL; /* we can't sensibly use this, sadly */
+
+ pty_term_width = cfg->width;
+ pty_term_height = cfg->height;
if (pty_master_fd < 0)
pty_open_master();
{
struct termios attrs;
tcgetattr(pty_master_fd, &attrs);
- attrs.c_cc[VERASE] = cfg.bksp_is_delete ? '\177' : '\010';
+ attrs.c_cc[VERASE] = cfg->bksp_is_delete ? '\177' : '\010';
tcsetattr(pty_master_fd, TCSANOW, &attrs);
}
* Stamp utmp (that is, tell the utmp helper process to do so),
* or not.
*/
- if (!cfg.stamp_utmp)
+ if (!cfg->stamp_utmp)
close(pty_utmp_helper_pipe); /* just let the child process die */
else {
- char *location = get_x_display();
+ char *location = get_x_display(pty_frontend);
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);
slavefd = open(pty_name, O_RDWR);
if (slavefd < 0) {
perror("slave pty: open");
- exit(1);
+ _exit(1);
}
close(pty_master_fd);
for (i = 3; i < 1024; i++)
close(i);
{
- char term_env_var[10 + sizeof(cfg.termtype)];
- sprintf(term_env_var, "TERM=%s", cfg.termtype);
+ char term_env_var[10 + sizeof(cfg->termtype)];
+ sprintf(term_env_var, "TERM=%s", cfg->termtype);
putenv(term_env_var);
}
/*
* parent, particularly by things like sh -c 'pterm &' and
* some window managers. Reverse this for our child process.
*/
- signal(SIGINT, SIG_DFL);
- signal(SIGQUIT, SIG_DFL);
+ putty_signal(SIGINT, SIG_DFL);
+ putty_signal(SIGQUIT, SIG_DFL);
if (pty_argv)
execvp(pty_argv[0], pty_argv);
else {
char *shell = getenv("SHELL");
char *shellname;
- if (cfg.login_shell) {
+ if (cfg->login_shell) {
char *p = strrchr(shell, '/');
shellname = smalloc(2+strlen(shell));
p = p ? p+1 : shell;
* If we're here, exec has gone badly foom.
*/
perror("exec");
- exit(127);
+ _exit(127);
} else {
- close(slavefd);
pty_child_pid = pid;
pty_child_dead = FALSE;
- signal(SIGCHLD, sigchld_handler);
- }
+ }
return NULL;
}
/*
+ * Stub routine (we don't have any need to reconfigure this backend).
+ */
+static void pty_reconfig(void *handle, Config *cfg)
+{
+}
+
+/*
+ * Stub routine (never called in pterm
+ */
+static void pty_free(void *handle)
+{
+}
+
+
+/*
* Called to send data down the pty.
*/
-static int pty_send(char *buf, int len)
+static int pty_send(void *handle, char *buf, int len)
{
if (pty_master_fd < 0)
return 0; /* ignore all writes if fd closed */
/*
* Called to query the current socket sendability status.
*/
-static int pty_sendbuffer(void)
+static int pty_sendbuffer(void *handle)
{
return 0;
}
/*
* Called to set the size of the window
*/
-static void pty_size(int width, int height)
+static void pty_size(void *handle, int width, int height)
{
struct winsize size;
size.ws_row = (unsigned short)pty_term_height;
size.ws_col = (unsigned short)pty_term_width;
- size.ws_xpixel = (unsigned short) pty_term_width * font_dimension(0);
- size.ws_ypixel = (unsigned short) pty_term_height * font_dimension(1);
+ size.ws_xpixel = (unsigned short) pty_term_width *
+ font_dimension(pty_frontend, 0);
+ size.ws_ypixel = (unsigned short) pty_term_height *
+ font_dimension(pty_frontend, 1);
ioctl(pty_master_fd, TIOCSWINSZ, (void *)&size);
return;
}
/*
* Send special codes.
*/
-static void pty_special(Telnet_Special code)
+static void pty_special(void *handle, Telnet_Special code)
{
/* Do nothing! */
return;
}
-static Socket pty_socket(void)
+static Socket pty_socket(void *handle)
{
return NULL; /* shouldn't ever be needed */
}
-static int pty_sendok(void)
+static int pty_sendok(void *handle)
{
return 1;
}
-static void pty_unthrottle(int backlog)
+static void pty_unthrottle(void *handle, int backlog)
{
/* do nothing */
}
-static int pty_ldisc(int option)
+static int pty_ldisc(void *handle, int option)
{
return 0; /* neither editing nor echoing */
}
-static int pty_exitcode(void)
+static void pty_provide_ldisc(void *handle, void *ldisc)
+{
+ /* This is a stub. */
+}
+
+static void pty_provide_logctx(void *handle, void *logctx)
+{
+ /* This is a stub. */
+}
+
+static int pty_exitcode(void *handle)
{
if (!pty_child_dead)
return -1; /* not dead yet */
Backend pty_backend = {
pty_init,
+ pty_free,
+ pty_reconfig,
pty_send,
pty_sendbuffer,
pty_size,
pty_exitcode,
pty_sendok,
pty_ldisc,
+ pty_provide_ldisc,
+ pty_provide_logctx,
pty_unthrottle,
1
};