sudo-1.7.4p4/exec.c - nest-learning-thermostat/5.0.1/sudo - Git at Google

 /*
  * Copyright (c) 2009-2010 Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */

 #include <config.h>

 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/wait.h>
 #ifdef HAVE_TERMIOS_H
 # include <termios.h>
 #else
 # include <termio.h>
 #endif /* HAVE_TERMIOS_H */
 #include <sys/ioctl.h>
 #ifdef HAVE_SYS_SELECT_H
 # include <sys/select.h>
 #endif /* HAVE_SYS_SELECT_H */
 #include <stdio.h>
 #ifdef STDC_HEADERS
 # include <stdlib.h>
 # include <stddef.h>
 #else
 # ifdef HAVE_STDLIB_H
 #  include <stdlib.h>
 # endif
 #endif /* STDC_HEADERS */
 #ifdef HAVE_STRING_H
 # include <string.h>
 #endif /* HAVE_STRING_H */
 #ifdef HAVE_STRINGS_H
 # include <strings.h>
 #endif /* HAVE_STRINGS_H */
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif /* HAVE_UNISTD_H */
 #if TIME_WITH_SYS_TIME
 # include <time.h>
 #endif
 #ifdef HAVE_SETLOCALE
 # include <locale.h>
 #endif
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #ifdef HAVE_SELINUX
 # include <selinux/selinux.h>
 #endif

 #include "sudo.h"
 #include "sudo_exec.h"

 /* shared with exec_pty.c */
 sig_atomic_t recvsig[NSIG];
 void handler __P((int s));

 /*
  * Like execve(2) but falls back to running through /bin/sh
  * ala execvp(3) if we get ENOEXEC.
  */
 int
 my_execve(path, argv, envp)
     const char *path;
     char *argv[];
     char *envp[];
 {
     execve(path, argv, envp);
     if (errno == ENOEXEC) {
 	argv--;			/* at least one extra slot... */
 	argv[0] = "sh";
 	argv[1] = (char *)path;
 	execve(_PATH_BSHELL, argv, envp);
     }
     return -1;
 }

 /*
  * Fork and execute a command, returns the child's pid.
  * Sends errno back on sv[1] if execve() fails.
  */
 static int fork_cmnd(path, argv, envp, sv, rbac_enabled)
     const char *path;
     char *argv[];
     char *envp[];
     int sv[2];
     int rbac_enabled;
 {
     struct command_status cstat;
     sigaction_t sa;
     int pid;

     zero_bytes(&sa, sizeof(sa));
     sigemptyset(&sa.sa_mask);
     sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */
     sa.sa_handler = handler;
     sigaction(SIGCONT, &sa, NULL);

     pid = fork();
     switch (pid) {
     case -1:
 	error(1, "fork");
 	break;
     case 0:
 	/* child */
 	close(sv[0]);
 	fcntl(sv[1], F_SETFD, FD_CLOEXEC);
 	if (exec_setup(rbac_enabled, user_ttypath, -1) == TRUE) {
 	    /* headed for execve() */
 	    closefrom(def_closefrom);
 #ifdef HAVE_SELINUX
 	    if (rbac_enabled)
 		selinux_execve(path, argv, envp);
 	    else
 #endif
 		my_execve(path, argv, envp);
 	}
 	cstat.type = CMD_ERRNO;
 	cstat.val = errno;
 	send(sv[1], &cstat, sizeof(cstat), 0);
 	_exit(1);
     }
     return pid;
 }

 /*
  * Execute a command, potentially in a pty with I/O loggging.
  * This is a little bit tricky due to how POSIX job control works and
  * we fact that we have two different controlling terminals to deal with.
  */
 int
 sudo_execve(path, argv, envp, uid, cstat, dowait, bgmode)
     const char *path;
     char *argv[];
     char *envp[];
     uid_t uid;
     struct command_status *cstat;
     int dowait;
     int bgmode;
 {
     sigaction_t sa;
     fd_set *fdsr, *fdsw;
     int maxfd, n, nready, status, sv[2];
     int rbac_enabled = 0;
     int log_io;
     pid_t child;

     /* If running in background mode, fork and exit. */
     if (bgmode) {
 	switch (fork()) {
 	    case -1:
 		cstat->type = CMD_ERRNO;
 		cstat->val = errno;
 		return -1;
 	    case 0:
 		/* child continues */
 		break;
 	    default:
 		/* parent exits */
 		exit(0);
 	}
     }

 #ifdef _PATH_SUDO_IO_LOGDIR
     log_io = def_log_output || def_log_input || def_use_pty;
     if (log_io) {
 	if (!bgmode)
 	    pty_setup(uid);
 	io_log_open();
 	dowait = TRUE;
     }
 #endif /* _PATH_SUDO_IO_LOGDIR */

 #ifdef HAVE_SELINUX
     rbac_enabled = is_selinux_enabled() > 0 && user_role != NULL;
     if (rbac_enabled)
 	dowait = TRUE;
 #endif

     /*
      * If we don't need to wait for the command to finish, just exec it.
      */
     if (!dowait) {
 	exec_setup(FALSE, NULL, -1);
 	closefrom(def_closefrom);
 	my_execve(path, argv, envp);
 	cstat->type = CMD_ERRNO;
 	cstat->val = errno;
 	return(127);
     }

     /*
      * We communicate with the child over a bi-directional pair of sockets.
      * Parent sends signal info to child and child sends back wait status.
      */
     if (socketpair(PF_UNIX, SOCK_DGRAM, 0, sv) != 0)
 	error(1, "cannot create sockets");

     zero_bytes(&sa, sizeof(sa));
     sigemptyset(&sa.sa_mask);

     /* Note: HP-UX select() will not be interrupted if SA_RESTART set */
     sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */
     sa.sa_handler = handler;
     sigaction(SIGCHLD, &sa, NULL);
     sigaction(SIGHUP, &sa, NULL);
     sigaction(SIGINT, &sa, NULL);
     sigaction(SIGPIPE, &sa, NULL);
     sigaction(SIGQUIT, &sa, NULL);
     sigaction(SIGTERM, &sa, NULL);

     /* Max fd we will be selecting on. */
     maxfd = sv[0];

     /*
      * Child will run the command in the pty, parent will pass data
      * to and from pty.  Adjusts maxfd as needed.
      */
 #ifdef _PATH_SUDO_IO_LOGDIR
     if (log_io)
 	child = fork_pty(path, argv, envp, sv, rbac_enabled, &maxfd);
     else
 #endif
 	child = fork_cmnd(path, argv, envp, sv, rbac_enabled);
     close(sv[1]);

 #ifdef HAVE_SETLOCALE
     /*
      * I/O logging must be in the C locale for floating point numbers
      * to be logged consistently.
      */
     setlocale(LC_ALL, "C");
 #endif

     /*
      * In the event loop we pass input from user tty to master
      * and pass output from master to stdout and IO plugin.
      */
     fdsr = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
     fdsw = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
     for (;;) {
 	if (recvsig[SIGCHLD]) {
 	    pid_t pid;

 	    /*
 	     * If logging I/O, child is the intermediate process,
 	     * otherwise it is the command itself.
 	     */
 	    recvsig[SIGCHLD] = FALSE;
 	    do {
 #ifdef sudo_waitpid
 		pid = sudo_waitpid(child, &status, WUNTRACED|WNOHANG);
 #else
 		pid = wait(&status);
 #endif
 	    } while (pid == -1 && errno == EINTR);
 	    if (pid == child) {
 		/* If not logging I/O and child has exited we are done. */
 		if (!log_io) {
 		    if (WIFSTOPPED(status)) {
 			/* Child may not have privs to suspend us itself. */
 			kill(getpid(), WSTOPSIG(status));
 		    } else {
 			/* Child has exited, we are done. */
 			cstat->type = CMD_WSTATUS;
 			cstat->val = status;
 			return 0;
 		    }
 		}
 		/* Else we get ECONNRESET on sv[0] if child dies. */
 	    }
 	}

 	zero_bytes(fdsw, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
 	zero_bytes(fdsr, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));

 	FD_SET(sv[0], fdsr);
 #ifdef _PATH_SUDO_IO_LOGDIR
 	if (log_io)
 	    fd_set_iobs(fdsr, fdsw); /* XXX - better name */
 #endif
 	for (n = 0; n < NSIG; n++) {
 	    if (recvsig[n] && n != SIGCHLD) {
 		if (log_io) {
 		    FD_SET(sv[0], fdsw);
 		    break;
 		} else {
 		    /* nothing listening on sv[0], send directly */
 		    kill(child, n);
 		}
 	    }
 	}

 	if (recvsig[SIGCHLD])
 	    continue;
 	nready = select(maxfd + 1, fdsr, fdsw, NULL, NULL);
 	if (nready == -1) {
 	    if (errno == EINTR)
 		continue;
 	    error(1, "select failed");
 	}
 	if (FD_ISSET(sv[0], fdsr)) {
 	    /* read child status */
 	    n = recv(sv[0], cstat, sizeof(*cstat), 0);
 	    if (n == -1) {
 		if (errno == EINTR)
 		    continue;
 		/*
 		 * If not logging I/O we will receive ECONNRESET when
 		 * the command is executed.  It is safe to ignore this.
 		 */
 		if (log_io && errno != EAGAIN) {
 		    cstat->type = CMD_ERRNO;
 		    cstat->val = errno;
 		    break;
 		}
 	    }
 #ifdef _PATH_SUDO_IO_LOGDIR /* XXX */
 	    if (cstat->type == CMD_WSTATUS) {
 		if (WIFSTOPPED(cstat->val)) {
 		    /* Suspend parent and tell child how to resume on return. */
 		    n = suspend_parent(WSTOPSIG(cstat->val));
 		    recvsig[n] = TRUE;
 		    continue;
 		} else {
 		    /* Child exited or was killed, either way we are done. */
 		    break;
 		}
 	    } else
 #endif /* _PATH_SUDO_IO_LOGDIR */
 	    if (cstat->type == CMD_ERRNO) {
 		/* Child was unable to execute command or broken pipe. */
 		break;
 	    }
 	}

 #ifdef _PATH_SUDO_IO_LOGDIR
 	/* XXX - move this too */
 	if (FD_ISSET(sv[0], fdsw)) {
 	    for (n = 0; n < NSIG; n++) {
 		if (!recvsig[n])
 		    continue;
 		recvsig[n] = FALSE;
 		cstat->type = CMD_SIGNO;
 		cstat->val = n;
 		do {
 		    n = send(sv[0], cstat, sizeof(*cstat), 0);
 		} while (n == -1 && errno == EINTR);
 		if (n != sizeof(*cstat)) {
 		    recvsig[n] = TRUE;
 		    break;
 		}
 	    }
 	}
 	if (perform_io(fdsr, fdsw, cstat) != 0)
 	    break;
 #endif /* _PATH_SUDO_IO_LOGDIR */
     }

 #ifdef _PATH_SUDO_IO_LOGDIR
     if (log_io) {
 	/* Flush any remaining output and free pty-related memory. */
 	pty_close(cstat);
     }
 #endif /* _PATH_SUDO_IO_LOGDIR */

 #ifdef HAVE_SELINUX
     if (rbac_enabled) {
 	/* This is probably not needed in log_io mode. */
 	if (selinux_restore_tty() != 0)
 	    warningx("unable to restore tty label");
     }
 #endif

     efree(fdsr);
     efree(fdsw);

     return cstat->type == CMD_ERRNO ? -1 : 0;
 }

 /*
  * Generic handler for signals passed from parent -> child.
  * The recvsig[] array is checked in the main event loop.
  */
 void
 handler(s)
     int s;
 {
     recvsig[s] = TRUE;
 }
	/*
	* Copyright (c) 2009-2010 Todd C. Miller <Todd.Miller@courtesan.com>
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	#include <config.h>

	#include <sys/types.h>
	#include <sys/param.h>
	#include <sys/socket.h>
	#include <sys/stat.h>
	#include <sys/time.h>
	#include <sys/wait.h>
	#ifdef HAVE_TERMIOS_H
	# include <termios.h>
	#else
	# include <termio.h>
	#endif /* HAVE_TERMIOS_H */
	#include <sys/ioctl.h>
	#ifdef HAVE_SYS_SELECT_H
	# include <sys/select.h>
	#endif /* HAVE_SYS_SELECT_H */
	#include <stdio.h>
	#ifdef STDC_HEADERS
	# include <stdlib.h>
	# include <stddef.h>
	#else
	# ifdef HAVE_STDLIB_H
	# include <stdlib.h>
	# endif
	#endif /* STDC_HEADERS */
	#ifdef HAVE_STRING_H
	# include <string.h>
	#endif /* HAVE_STRING_H */
	#ifdef HAVE_STRINGS_H
	# include <strings.h>
	#endif /* HAVE_STRINGS_H */
	#ifdef HAVE_UNISTD_H
	# include <unistd.h>
	#endif /* HAVE_UNISTD_H */
	#if TIME_WITH_SYS_TIME
	# include <time.h>
	#endif
	#ifdef HAVE_SETLOCALE
	# include <locale.h>
	#endif
	#include <errno.h>
	#include <fcntl.h>
	#include <signal.h>
	#ifdef HAVE_SELINUX
	# include <selinux/selinux.h>
	#endif

	#include "sudo.h"
	#include "sudo_exec.h"

	/* shared with exec_pty.c */
	sig_atomic_t recvsig[NSIG];
	void handler __P((int s));

	/*
	* Like execve(2) but falls back to running through /bin/sh
	* ala execvp(3) if we get ENOEXEC.
	*/
	int
	my_execve(path, argv, envp)
	const char *path;
	char *argv[];
	char *envp[];
	{
	execve(path, argv, envp);
	if (errno == ENOEXEC) {
	argv--; /* at least one extra slot... */
	argv[0] = "sh";
	argv[1] = (char *)path;
	execve(_PATH_BSHELL, argv, envp);
	}
	return -1;
	}

	/*
	* Fork and execute a command, returns the child's pid.
	* Sends errno back on sv[1] if execve() fails.
	*/
	static int fork_cmnd(path, argv, envp, sv, rbac_enabled)
	const char *path;
	char *argv[];
	char *envp[];
	int sv[2];
	int rbac_enabled;
	{
	struct command_status cstat;
	sigaction_t sa;
	int pid;

	zero_bytes(&sa, sizeof(sa));
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */
	sa.sa_handler = handler;
	sigaction(SIGCONT, &sa, NULL);

	pid = fork();
	switch (pid) {
	case -1:
	error(1, "fork");
	break;
	case 0:
	/* child */
	close(sv[0]);
	fcntl(sv[1], F_SETFD, FD_CLOEXEC);
	if (exec_setup(rbac_enabled, user_ttypath, -1) == TRUE) {
	/* headed for execve() */
	closefrom(def_closefrom);
	#ifdef HAVE_SELINUX
	if (rbac_enabled)
	selinux_execve(path, argv, envp);
	else
	#endif
	my_execve(path, argv, envp);
	}
	cstat.type = CMD_ERRNO;
	cstat.val = errno;
	send(sv[1], &cstat, sizeof(cstat), 0);
	_exit(1);
	}
	return pid;
	}

	/*
	* Execute a command, potentially in a pty with I/O loggging.
	* This is a little bit tricky due to how POSIX job control works and
	* we fact that we have two different controlling terminals to deal with.
	*/
	int
	sudo_execve(path, argv, envp, uid, cstat, dowait, bgmode)
	const char *path;
	char *argv[];
	char *envp[];
	uid_t uid;
	struct command_status *cstat;
	int dowait;
	int bgmode;
	{
	sigaction_t sa;
	fd_set fdsr, fdsw;
	int maxfd, n, nready, status, sv[2];
	int rbac_enabled = 0;
	int log_io;
	pid_t child;

	/* If running in background mode, fork and exit. */
	if (bgmode) {
	switch (fork()) {
	case -1:
	cstat->type = CMD_ERRNO;
	cstat->val = errno;
	return -1;
	case 0:
	/* child continues */
	break;
	default:
	/* parent exits */
	exit(0);
	}
	}

	#ifdef _PATH_SUDO_IO_LOGDIR
	log_io = def_log_output \|\| def_log_input \|\| def_use_pty;
	if (log_io) {
	if (!bgmode)
	pty_setup(uid);
	io_log_open();
	dowait = TRUE;
	}
	#endif /* _PATH_SUDO_IO_LOGDIR */

	#ifdef HAVE_SELINUX
	rbac_enabled = is_selinux_enabled() > 0 && user_role != NULL;
	if (rbac_enabled)
	dowait = TRUE;
	#endif

	/*
	* If we don't need to wait for the command to finish, just exec it.
	*/
	if (!dowait) {
	exec_setup(FALSE, NULL, -1);
	closefrom(def_closefrom);
	my_execve(path, argv, envp);
	cstat->type = CMD_ERRNO;
	cstat->val = errno;
	return(127);
	}

	/*
	* We communicate with the child over a bi-directional pair of sockets.
	* Parent sends signal info to child and child sends back wait status.
	*/
	if (socketpair(PF_UNIX, SOCK_DGRAM, 0, sv) != 0)
	error(1, "cannot create sockets");

	zero_bytes(&sa, sizeof(sa));
	sigemptyset(&sa.sa_mask);

	/* Note: HP-UX select() will not be interrupted if SA_RESTART set */
	sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */
	sa.sa_handler = handler;
	sigaction(SIGCHLD, &sa, NULL);
	sigaction(SIGHUP, &sa, NULL);
	sigaction(SIGINT, &sa, NULL);
	sigaction(SIGPIPE, &sa, NULL);
	sigaction(SIGQUIT, &sa, NULL);
	sigaction(SIGTERM, &sa, NULL);

	/* Max fd we will be selecting on. */
	maxfd = sv[0];

	/*
	* Child will run the command in the pty, parent will pass data
	* to and from pty. Adjusts maxfd as needed.
	*/
	#ifdef _PATH_SUDO_IO_LOGDIR
	if (log_io)
	child = fork_pty(path, argv, envp, sv, rbac_enabled, &maxfd);
	else
	#endif
	child = fork_cmnd(path, argv, envp, sv, rbac_enabled);
	close(sv[1]);

	#ifdef HAVE_SETLOCALE
	/*
	* I/O logging must be in the C locale for floating point numbers
	* to be logged consistently.
	*/
	setlocale(LC_ALL, "C");
	#endif

	/*
	* In the event loop we pass input from user tty to master
	* and pass output from master to stdout and IO plugin.
	*/
	fdsr = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
	fdsw = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
	for (;;) {
	if (recvsig[SIGCHLD]) {
	pid_t pid;

	/*
	* If logging I/O, child is the intermediate process,
	* otherwise it is the command itself.
	*/
	recvsig[SIGCHLD] = FALSE;
	do {
	#ifdef sudo_waitpid
	pid = sudo_waitpid(child, &status, WUNTRACED\|WNOHANG);
	#else
	pid = wait(&status);
	#endif
	} while (pid == -1 && errno == EINTR);
	if (pid == child) {
	/* If not logging I/O and child has exited we are done. */
	if (!log_io) {
	if (WIFSTOPPED(status)) {
	/* Child may not have privs to suspend us itself. */
	kill(getpid(), WSTOPSIG(status));
	} else {
	/* Child has exited, we are done. */
	cstat->type = CMD_WSTATUS;
	cstat->val = status;
	return 0;
	}
	}
	/* Else we get ECONNRESET on sv[0] if child dies. */
	}
	}

	zero_bytes(fdsw, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
	zero_bytes(fdsr, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));

	FD_SET(sv[0], fdsr);
	#ifdef _PATH_SUDO_IO_LOGDIR
	if (log_io)
	fd_set_iobs(fdsr, fdsw); /* XXX - better name */
	#endif
	for (n = 0; n < NSIG; n++) {
	if (recvsig[n] && n != SIGCHLD) {
	if (log_io) {
	FD_SET(sv[0], fdsw);
	break;
	} else {
	/* nothing listening on sv[0], send directly */
	kill(child, n);
	}
	}
	}

	if (recvsig[SIGCHLD])
	continue;
	nready = select(maxfd + 1, fdsr, fdsw, NULL, NULL);
	if (nready == -1) {
	if (errno == EINTR)
	continue;
	error(1, "select failed");
	}
	if (FD_ISSET(sv[0], fdsr)) {
	/* read child status */
	n = recv(sv[0], cstat, sizeof(*cstat), 0);
	if (n == -1) {
	if (errno == EINTR)
	continue;
	/*
	* If not logging I/O we will receive ECONNRESET when
	* the command is executed. It is safe to ignore this.
	*/
	if (log_io && errno != EAGAIN) {
	cstat->type = CMD_ERRNO;
	cstat->val = errno;
	break;
	}
	}
	#ifdef _PATH_SUDO_IO_LOGDIR /* XXX */
	if (cstat->type == CMD_WSTATUS) {
	if (WIFSTOPPED(cstat->val)) {
	/* Suspend parent and tell child how to resume on return. */
	n = suspend_parent(WSTOPSIG(cstat->val));
	recvsig[n] = TRUE;
	continue;
	} else {
	/* Child exited or was killed, either way we are done. */
	break;
	}
	} else
	#endif /* _PATH_SUDO_IO_LOGDIR */
	if (cstat->type == CMD_ERRNO) {
	/* Child was unable to execute command or broken pipe. */
	break;
	}
	}

	#ifdef _PATH_SUDO_IO_LOGDIR
	/* XXX - move this too */
	if (FD_ISSET(sv[0], fdsw)) {
	for (n = 0; n < NSIG; n++) {
	if (!recvsig[n])
	continue;
	recvsig[n] = FALSE;
	cstat->type = CMD_SIGNO;
	cstat->val = n;
	do {
	n = send(sv[0], cstat, sizeof(*cstat), 0);
	} while (n == -1 && errno == EINTR);
	if (n != sizeof(*cstat)) {
	recvsig[n] = TRUE;
	break;
	}
	}
	}
	if (perform_io(fdsr, fdsw, cstat) != 0)
	break;
	#endif /* _PATH_SUDO_IO_LOGDIR */
	}

	#ifdef _PATH_SUDO_IO_LOGDIR
	if (log_io) {
	/* Flush any remaining output and free pty-related memory. */
	pty_close(cstat);
	}
	#endif /* _PATH_SUDO_IO_LOGDIR */

	#ifdef HAVE_SELINUX
	if (rbac_enabled) {
	/* This is probably not needed in log_io mode. */
	if (selinux_restore_tty() != 0)
	warningx("unable to restore tty label");
	}
	#endif

	efree(fdsr);
	efree(fdsw);

	return cstat->type == CMD_ERRNO ? -1 : 0;
	}

	/*
	* Generic handler for signals passed from parent -> child.
	* The recvsig[] array is checked in the main event loop.
	*/
	void
	handler(s)
	int s;
	{
	recvsig[s] = TRUE;
	}