+++ /dev/null
-/*
- * 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;
-}
projects / debian / sudo / blobdiff