path: root/usr.bin/sudo/sudo.c

/*
 * Copyright (c) 1993-1996,1998-2007 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.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 *
 * For a brief history of sudo, please see the HISTORY file included
 * with this distribution.
 */

#define _SUDO_MAIN

#ifdef __TANDEM
# include <floss.h>
#endif

#include <config.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/socket.h>
#ifdef HAVE_SETRLIMIT
# include <sys/time.h>
# include <sys/resource.h>
#endif
#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
# if defined(HAVE_MEMORY_H) && !defined(STDC_HEADERS)
#  include <memory.h>
# endif
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
#  include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_ERR_H
# include <err.h>
#else
# include "emul/err.h"
#endif /* HAVE_ERR_H */
#include <pwd.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <grp.h>
#if TIME_WITH_SYS_TIME
# include <time.h>
#endif
#ifdef HAVE_SETLOCALE
# include <locale.h>
#endif
#include <netinet/in.h>
#include <netdb.h>
#if defined(HAVE_GETPRPWNAM) && defined(HAVE_SET_AUTH_PARAMETERS)
# ifdef __hpux
#  undef MAXINT
#  include <hpsecurity.h>
# else
#  include <sys/security.h>
# endif /* __hpux */
# include <prot.h>
#endif /* HAVE_GETPRPWNAM && HAVE_SET_AUTH_PARAMETERS */
#ifdef HAVE_LOGIN_CAP_H
# include <login_cap.h>
# ifndef LOGIN_DEFROOTCLASS
#  define LOGIN_DEFROOTCLASS	"daemon"
# endif
#endif
#ifdef HAVE_PROJECT_H
# include <project.h>
# include <sys/task.h>
#endif
#ifdef HAVE_SELINUX
# include <selinux/selinux.h>
#endif

#include "sudo.h"
#include "interfaces.h"
#include "version.h"

#ifndef lint
__unused __unused static const char rcsid[] = "$Sudo: sudo.c,v 1.369.2.43 2008/07/02 10:28:43 millert Exp $";
#endif /* lint */

/*
 * Prototypes
 */
static int init_vars			__P((int, char **));
static int parse_args			__P((int, char **));
static void check_sudoers		__P((void));
static void initial_setup		__P((void));
static void set_loginclass		__P((struct passwd *));
static void set_project			__P((struct passwd *));
static void usage			__P((int))
					    __attribute__((__noreturn__));
static void usage_excl			__P((int))
					    __attribute__((__noreturn__));
static void usage_excl			__P((int));
static struct passwd *get_authpw	__P((void));
extern int sudo_edit			__P((int, char **, char **));
extern void list_matches		__P((void));
extern char **rebuild_env		__P((char **, int, int));
extern void validate_env_vars		__P((struct list_member *));
extern char **insert_env_vars		__P((char **, struct list_member *));
extern struct passwd *sudo_getpwnam	__P((const char *));
extern struct passwd *sudo_getpwuid	__P((uid_t));
extern struct passwd *sudo_pwdup	__P((const struct passwd *));

/*
 * Globals
 */
int Argc, NewArgc;
char **Argv, **NewArgv;
char *prev_user;
struct sudo_user sudo_user;
struct passwd *auth_pw;
FILE *sudoers_fp;
struct interface *interfaces;
int num_interfaces;
int tgetpass_flags;
uid_t timestamp_uid;
extern int errorlineno;
#if defined(RLIMIT_CORE) && !defined(SUDO_DEVEL)
static struct rlimit corelimit;
#endif /* RLIMIT_CORE && !SUDO_DEVEL */
#ifdef HAVE_LOGIN_CAP_H
login_cap_t *lc;
#endif /* HAVE_LOGIN_CAP_H */
#ifdef HAVE_BSD_AUTH_H
char *login_style;
#endif /* HAVE_BSD_AUTH_H */
sigaction_t saved_sa_int, saved_sa_quit, saved_sa_tstp;


int
main(argc, argv, envp)
    int argc;
    char **argv;
    char **envp;
{
    int validated;
    int fd;
    int cmnd_status;
    int sudo_mode;
    int pwflag;
    sigaction_t sa;
    extern int printmatches;
    extern char **environ;

#ifdef HAVE_SETLOCALE
    setlocale(LC_ALL, "");
#endif

    Argv = argv;
    if ((Argc = argc) < 1)
	usage(1);

    /* Must be done as the first thing... */
#if defined(HAVE_GETPRPWNAM) && defined(HAVE_SET_AUTH_PARAMETERS)
    (void) set_auth_parameters(Argc, Argv);
# ifdef HAVE_INITPRIVS
    initprivs();
# endif
#endif /* HAVE_GETPRPWNAM && HAVE_SET_AUTH_PARAMETERS */

    if (geteuid() != 0)
	errx(1, "must be setuid root");

    /*
     * Signal setup:
     *	Ignore keyboard-generated signals so the user cannot interrupt
     *  us at some point and avoid the logging.
     *  Install handler to wait for children when they exit.
     */
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = SA_RESTART;
    sa.sa_handler = SIG_IGN;
    (void) sigaction(SIGINT, &sa, &saved_sa_int);
    (void) sigaction(SIGQUIT, &sa, &saved_sa_quit);
    (void) sigaction(SIGTSTP, &sa, &saved_sa_tstp);

    /*
     * Turn off core dumps and close open files.
     */
    initial_setup();
    setpwent();

    /* Parse our arguments. */
    sudo_mode = parse_args(Argc, Argv);

    /* Setup defaults data structures. */
    init_defaults();

    /* Load the list of local ip addresses and netmasks.  */
    load_interfaces();

    pwflag = 0;
    if (ISSET(sudo_mode, MODE_SHELL))
	user_cmnd = "shell";
    else if (ISSET(sudo_mode, MODE_EDIT))
	user_cmnd = "sudoedit";
    else
	switch (sudo_mode) {
	    case MODE_VERSION:
		(void) printf("Sudo version %s\n", version);
		if (getuid() == 0) {
		    putchar('\n');
		    (void) printf("Sudoers path: %s\n", _PATH_SUDOERS);
		    dump_auth_methods();
		    dump_defaults();
		    dump_interfaces();
		}
		exit(0);
		break;
	    case MODE_HELP:
		usage(0);
		break;
	    case MODE_VALIDATE:
		user_cmnd = "validate";
		pwflag = I_VERIFYPW;
		break;
	    case MODE_KILL:
	    case MODE_INVALIDATE:
		user_cmnd = "kill";
		pwflag = -1;
		break;
	    case MODE_LISTDEFS:
		list_options();
		exit(0);
		break;
	    case MODE_LIST:
		user_cmnd = "list";
		pwflag = I_LISTPW;
		printmatches = 1;
		break;
	}

    /* Must have a command to run... */
    if (user_cmnd == NULL && NewArgc == 0)
	usage(1);

    cmnd_status = init_vars(sudo_mode, environ);

#ifdef HAVE_LDAP
    validated = sudo_ldap_check(pwflag);

    /* Skip reading /etc/sudoers if LDAP told us to */
    if (!def_ignore_local_sudoers) {
	int v;

	check_sudoers();	/* check mode/owner on _PATH_SUDOERS */

	/* Local sudoers file overrides LDAP if we have a match. */
	v = sudoers_lookup(pwflag);
	if (validated == VALIDATE_ERROR || ISSET(v, VALIDATE_OK))
	    validated = v;
    }
#else
    check_sudoers();	/* check mode/owner on _PATH_SUDOERS */

    /* Validate the user but don't search for pseudo-commands. */
    validated = sudoers_lookup(pwflag);
#endif
    if (safe_cmnd == NULL)
	safe_cmnd = estrdup(user_cmnd);

    /*
     * Look up the timestamp dir owner if one is specified.
     */
    if (def_timestampowner) {
	struct passwd *pw;

	if (*def_timestampowner == '#')
	    pw = getpwuid(atoi(def_timestampowner + 1));
	else
	    pw = getpwnam(def_timestampowner);
	if (!pw)
	    log_error(0, "timestamp owner (%s): No such user",
		def_timestampowner);
	timestamp_uid = pw->pw_uid;
    }

    /* This goes after the sudoers parse since we honor sudoers options. */
    if (sudo_mode == MODE_KILL || sudo_mode == MODE_INVALIDATE) {
	remove_timestamp((sudo_mode == MODE_KILL));
	exit(0);
    }

    if (ISSET(validated, VALIDATE_ERROR))
	log_error(0, "parse error in %s near line %d", _PATH_SUDOERS,
	    errorlineno);

    /* Is root even allowed to run sudo? */
    if (user_uid == 0 && !def_root_sudo) {
	(void) fprintf(stderr,
	    "Sorry, %s has been configured to not allow root to run it.\n",
	    getprogname());
	exit(1);
    }

    /* If given the -P option, set the "preserve_groups" flag. */
    if (ISSET(sudo_mode, MODE_PRESERVE_GROUPS))
	def_preserve_groups = TRUE;

    /* If no command line args and "set_home" is not set, error out. */
    if (ISSET(sudo_mode, MODE_IMPLIED_SHELL) && !def_shell_noargs)
	usage(1);

    /* Bail if a tty is required and we don't have one.  */
    if (def_requiretty) {
	if ((fd = open(_PATH_TTY, O_RDWR|O_NOCTTY)) == -1)
	    log_error(NO_MAIL, "sorry, you must have a tty to run sudo");
	else
	    (void) close(fd);
    }

    /* User may have overriden environment resetting via the -E flag. */
    if (ISSET(sudo_mode, MODE_PRESERVE_ENV) && ISSET(validated, FLAG_SETENV))
	def_env_reset = FALSE;

    /* Build a new environment that avoids any nasty bits. */
    environ = rebuild_env(environ, sudo_mode, ISSET(validated, FLAG_NOEXEC));

    /* Fill in passwd struct based on user we are authenticating as.  */
    auth_pw = get_authpw();

    /* Require a password if sudoers says so.  */
    if (!ISSET(validated, FLAG_NOPASS))
	check_user(validated);

    /* If run as root with SUDO_USER set, set sudo_user.pw to that user. */
    if (user_uid == 0 && prev_user != NULL && strcmp(prev_user, "root") != 0) {
	    struct passwd *pw;

	    if ((pw = sudo_getpwnam(prev_user)) != NULL) {
		    efree(sudo_user.pw);
		    sudo_user.pw = pw;
	    }
    }

    if (ISSET(validated, VALIDATE_OK)) {
	/* Finally tell the user if the command did not exist. */
	if (cmnd_status == NOT_FOUND_DOT) {
	    warnx("ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.", user_cmnd, user_cmnd, user_cmnd);
	    exit(1);
	} else if (cmnd_status == NOT_FOUND) {
	    warnx("%s: command not found", user_cmnd);
	    exit(1);
	}

	/* If user specified env vars make sure sudoers allows it. */
	if (ISSET(sudo_mode, MODE_RUN) && !ISSET(validated, FLAG_SETENV)) {
	    if (ISSET(sudo_mode, MODE_PRESERVE_ENV))
		log_error(NO_MAIL,
		    "sorry, you are not allowed to preserve the environment");
	    else
		validate_env_vars(sudo_user.env_vars);
	}

	log_auth(validated, 1);
	if (sudo_mode == MODE_VALIDATE)
	    exit(0);
	else if (sudo_mode == MODE_LIST) {
	    list_matches();
#ifdef HAVE_LDAP
	    sudo_ldap_list_matches();
#endif
	    exit(0);
	}

	/* Override user's umask if configured to do so. */
	if (def_umask != 0777)
	    (void) umask(def_umask);

	/* Restore coredumpsize resource limit. */
#if defined(RLIMIT_CORE) && !defined(SUDO_DEVEL)
	(void) setrlimit(RLIMIT_CORE, &corelimit);
#endif /* RLIMIT_CORE && !SUDO_DEVEL */

	/* Become specified user or root if executing a command. */
	if (ISSET(sudo_mode, MODE_RUN))
	    set_perms(PERM_FULL_RUNAS);

	/* Close the password and group files */
	endpwent();
	endgrent();

	if (ISSET(sudo_mode, MODE_LOGIN_SHELL)) {
	    char *p;

	    /* Convert /bin/sh -> -sh so shell knows it is a login shell */
	    if ((p = strrchr(NewArgv[0], '/')) == NULL)
		p = NewArgv[0];
	    *p = '-';
	    NewArgv[0] = p;

	    /* Change to target user's homedir. */
	    if (chdir(runas_pw->pw_dir) == -1)
		warn("unable to change directory to %s", runas_pw->pw_dir);
	}

	if (ISSET(sudo_mode, MODE_EDIT))
	    exit(sudo_edit(NewArgc, NewArgv, envp));

	/* Insert user-specified environment variables. */
	environ = insert_env_vars(environ, sudo_user.env_vars);

	/* Restore signal handlers before we exec. */
	(void) sigaction(SIGINT, &saved_sa_int, NULL);
	(void) sigaction(SIGQUIT, &saved_sa_quit, NULL);
	(void) sigaction(SIGTSTP, &saved_sa_tstp, NULL);

#ifndef PROFILING
	if (ISSET(sudo_mode, MODE_BACKGROUND) && fork() > 0)
	    exit(0);
	else {
#ifdef HAVE_SELINUX
	    if (is_selinux_enabled() > 0 && user_role != NULL)
		selinux_exec(user_role, user_type, NewArgv, environ,
		    ISSET(sudo_mode, MODE_LOGIN_SHELL));
#endif
	    execve(safe_cmnd, NewArgv, environ);
	}
#else
	exit(0);
#endif /* PROFILING */
	/*
	 * If we got here then the exec() failed...
	 */
	if (errno == ENOEXEC) {
	    NewArgv--;			/* at least one extra slot... */
	    NewArgv[0] = "sh";
	    NewArgv[1] = safe_cmnd;
	    execve(_PATH_BSHELL, NewArgv, environ);
	}
	warn("unable to execute %s", safe_cmnd);
	exit(127);
    } else if (ISSET(validated, FLAG_NO_USER) || (validated & FLAG_NO_HOST)) {
	log_auth(validated, 1);
	exit(1);
    } else if (ISSET(validated, VALIDATE_NOT_OK)) {
	if (def_path_info) {
	    /*
	     * We'd like to not leak path info at all here, but that can
	     * *really* confuse the users.  To really close the leak we'd
	     * have to say "not allowed to run foo" even when the problem
	     * is just "no foo in path" since the user can trivially set
	     * their path to just contain a single dir.
	     */
	    log_auth(validated,
		!(cmnd_status == NOT_FOUND_DOT || cmnd_status == NOT_FOUND));
	    if (cmnd_status == NOT_FOUND)
		warnx("%s: command not found", user_cmnd);
	    else if (cmnd_status == NOT_FOUND_DOT)
		warnx("ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.", user_cmnd, user_cmnd, user_cmnd);
	} else {
	    /* Just tell the user they are not allowed to run foo. */
	    log_auth(validated, 1);
	}
	exit(1);
    } else {
	/* should never get here */
	log_auth(validated, 1);
	exit(1);
    }
    exit(0);	/* not reached */
}

/*
 * Initialize timezone, set umask, fill in ``sudo_user'' struct and
 * load the ``interfaces'' array.
 */
static int
init_vars(sudo_mode, envp)
    int sudo_mode;
    char **envp;
{
    char *p, **ep, thost[MAXHOSTNAMELEN];
    int nohostname, rval;

    /* Sanity check command from user. */
    if (user_cmnd == NULL && strlen(NewArgv[0]) >= PATH_MAX)
	errx(1, "%s: File name too long", NewArgv[0]);

#ifdef HAVE_TZSET
    (void) tzset();		/* set the timezone if applicable */
#endif /* HAVE_TZSET */

    /* Default value for cmnd and cwd, overridden later. */
    if (user_cmnd == NULL)
	user_cmnd = NewArgv[0];
    (void) strlcpy(user_cwd, "unknown", sizeof(user_cwd));

    /*
     * We avoid gethostbyname() if possible since we don't want
     * sudo to block if DNS or NIS is hosed.
     * "host" is the (possibly fully-qualified) hostname and
     * "shost" is the unqualified form of the hostname.
     */
    nohostname = gethostname(thost, sizeof(thost));
    if (nohostname)
	user_host = user_shost = "localhost";
    else {
	user_host = estrdup(thost);
	if (def_fqdn) {
	    /* Defer call to set_fqdn() until log_error() is safe. */
	    user_shost = user_host;
	} else {
	    if ((p = strchr(user_host, '.'))) {
		*p = '\0';
		user_shost = estrdup(user_host);
		*p = '.';
	    } else {
		user_shost = user_host;
	    }
	}
    }

    if ((p = ttyname(STDIN_FILENO)) || (p = ttyname(STDOUT_FILENO))) {
	user_tty = user_ttypath = estrdup(p);
	if (strncmp(user_tty, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
	    user_tty += sizeof(_PATH_DEV) - 1;
    } else
	user_tty = "unknown";

    for (ep = envp; *ep; ep++) {
	switch (**ep) {
	    case 'P':
		if (strncmp("PATH=", *ep, 5) == 0)
		    user_path = *ep + 5;
		break;
	    case 'S':
		if (strncmp("SHELL=", *ep, 6) == 0)
		    user_shell = *ep + 6;
		else if (!user_prompt && strncmp("SUDO_PROMPT=", *ep, 12) == 0)
		    user_prompt = *ep + 12;
		else if (strncmp("SUDO_USER=", *ep, 10) == 0)
		    prev_user = *ep + 10;
		break;

	    }
    }

    /*
     * Get a local copy of the user's struct passwd with the shadow password
     * if necessary.  It is assumed that euid is 0 at this point so we
     * can read the shadow passwd file if necessary.
     */
    if ((sudo_user.pw = sudo_getpwuid(getuid())) == NULL) {
	/* Need to make a fake struct passwd for logging to work. */
	struct passwd pw;
	char pw_name[MAX_UID_T_LEN + 1];

	pw.pw_uid = getuid();
	(void) snprintf(pw_name, sizeof(pw_name), "%lu",
	    (unsigned long) pw.pw_uid);
	pw.pw_name = pw_name;
	sudo_user.pw = &pw;

	/*
	 * If we are in -k/-K mode, just spew to stderr.  It is not unusual for
	 * users to place "sudo -k" in a .logout file which can cause sudo to
	 * be run during reboot after the YP/NIS/NIS+/LDAP/etc daemon has died.
	 */
	if (sudo_mode & (MODE_INVALIDATE|MODE_KILL))
	    errx(1, "uid %s does not exist in the passwd file!", pw_name);
	log_error(0, "uid %s does not exist in the passwd file!", pw_name);
    }
    if (user_shell == NULL || *user_shell == '\0')
	user_shell = sudo_user.pw->pw_shell;

    /* It is now safe to use log_error() and set_perms() */

#ifdef HAVE_GETGROUPS
    if ((user_ngroups = getgroups(0, NULL)) > 0) {
	user_groups = emalloc2(user_ngroups, sizeof(GETGROUPS_T));
	if (getgroups(user_ngroups, user_groups) < 0)
	    log_error(USE_ERRNO|MSG_ONLY, "can't get group vector");
    } else
	user_ngroups = 0;
#endif

    if (def_fqdn)
	set_fqdn();			/* may call log_error() */

    if (nohostname)
	log_error(USE_ERRNO|MSG_ONLY, "can't get hostname");

    set_runaspw(*user_runas);		/* may call log_error() */
    if (*user_runas[0] == '#') {
	if (runas_pw->pw_name != *user_runas && runas_pw->pw_name[0])
	    *user_runas = estrdup(runas_pw->pw_name);
    }

    /*
     * Get current working directory.  Try as user, fall back to root.
     */
    set_perms(PERM_USER);
    if (!getcwd(user_cwd, sizeof(user_cwd))) {
	set_perms(PERM_ROOT);
	if (!getcwd(user_cwd, sizeof(user_cwd))) {
	    warnx("cannot get working directory");
	    (void) strlcpy(user_cwd, "unknown", sizeof(user_cwd));
	}
    } else
	set_perms(PERM_ROOT);

    /*
     * If we were given the '-e', '-i' or '-s' options we need to redo
     * NewArgv and NewArgc.
     */
    if ((sudo_mode & (MODE_SHELL | MODE_EDIT))) {
	char **dst, **src = NewArgv;

	/* Allocate an extra slot for execve() failure (ENOEXEC). */
	NewArgv = (char **) emalloc2((++NewArgc + 2), sizeof(char *));
	NewArgv++;
	if (ISSET(sudo_mode, MODE_EDIT))
	    NewArgv[0] = "sudoedit";
	else if (ISSET(sudo_mode, MODE_LOGIN_SHELL))
	    NewArgv[0] = runas_pw->pw_shell;
	else if (user_shell && *user_shell)
	    NewArgv[0] = user_shell;
	else
	    errx(1, "unable to determine shell");

	/* copy the args from NewArgv */
	for (dst = NewArgv + 1; (*dst = *src) != NULL; ++src, ++dst)
	    continue;
    }

    /* Set login class if applicable. */
    set_loginclass(sudo_user.pw);

    /* Set project if applicable. */
    set_project(runas_pw);

    /* Resolve the path and return. */
    rval = FOUND;
    user_stat = emalloc(sizeof(struct stat));
    if (sudo_mode & (MODE_RUN | MODE_EDIT)) {
	if (ISSET(sudo_mode, MODE_RUN)) {
	    /* XXX - default_runas may be modified during parsing of sudoers */
	    set_perms(PERM_RUNAS);
	    rval = find_path(NewArgv[0], &user_cmnd, user_stat, user_path);
	    set_perms(PERM_ROOT);
	    if (rval != FOUND) {
		/* Failed as root, try as invoking user. */
		set_perms(PERM_USER);
		rval = find_path(NewArgv[0], &user_cmnd, user_stat, user_path);
		set_perms(PERM_ROOT);
	    }
	}

	/* set user_args */
	if (NewArgc > 1) {
	    char *to, **from;
	    size_t size, n;

	    /* If we didn't realloc NewArgv it is contiguous so just count. */
	    if (!(sudo_mode & (MODE_SHELL | MODE_EDIT))) {
		size = (size_t) (NewArgv[NewArgc-1] - NewArgv[1]) +
			strlen(NewArgv[NewArgc-1]) + 1;
	    } else {
		for (size = 0, from = NewArgv + 1; *from; from++)
		    size += strlen(*from) + 1;
	    }

	    /* Alloc and build up user_args. */
	    user_args = (char *) emalloc(size);
	    for (to = user_args, from = NewArgv + 1; *from; from++) {
		n = strlcpy(to, *from, size - (to - user_args));
		if (n >= size - (to - user_args))
		    errx(1, "internal error, init_vars() overflow");
		to += n;
		*to++ = ' ';
	    }
	    *--to = '\0';
	}
    }
    if ((user_base = strrchr(user_cmnd, '/')) != NULL)
	user_base++;
    else
	user_base = user_cmnd;

    return(rval);
}

/*
 * Command line argument parsing, can't use getopt(3).
 */
static int
parse_args(argc, argv)
    int argc;
    char **argv;
{
    int rval = MODE_RUN;		/* what mode is sudo to be run in? */
    int excl = 0;			/* exclusive arg, no others allowed */

    NewArgv = argv + 1;
    NewArgc = argc - 1;

    /* First, check to see if we were invoked as "sudoedit". */
    if (strcmp(getprogname(), "sudoedit") == 0) {
	rval = MODE_EDIT;
	excl = 'e';
    } else
	rval = MODE_RUN;

    while (NewArgc > 0) {
	if (NewArgv[0][0] == '-') {
	    if (NewArgv[0][1] != '\0' && NewArgv[0][2] != '\0') {
		warnx("please use single character options");
		usage(1);
	    }

	    switch (NewArgv[0][1]) {
		case 'p':
		    /* Must have an associated prompt. */
		    if (NewArgv[1] == NULL)
			usage(1);

		    user_prompt = NewArgv[1];
		    def_passprompt_override = TRUE;

		    NewArgc--;
		    NewArgv++;
		    break;
		case 'u':
		    /* Must have an associated runas user. */
		    if (NewArgv[1] == NULL)
			usage(1);

		    user_runas = &NewArgv[1];

		    NewArgc--;
		    NewArgv++;
		    break;
#ifdef HAVE_BSD_AUTH_H
		case 'a':
		    /* Must have an associated authentication style. */
		    if (NewArgv[1] == NULL)
			usage(1);

		    login_style = NewArgv[1];

		    NewArgc--;
		    NewArgv++;
		    break;
#endif
#ifdef HAVE_LOGIN_CAP_H
		case 'c':
		    /* Must have an associated login class. */
		    if (NewArgv[1] == NULL)
			usage(1);

		    login_class = NewArgv[1];
		    def_use_loginclass = TRUE;

		    NewArgc--;
		    NewArgv++;
		    break;
#endif
		case 'b':
		    SET(rval, MODE_BACKGROUND);
		    break;
		case 'e':
		    rval = MODE_EDIT;
		    if (excl && excl != 'e')
			usage_excl(1);
		    excl = 'e';
		    break;
		case 'v':
		    rval = MODE_VALIDATE;
		    if (excl && excl != 'v')
			usage_excl(1);
		    excl = 'v';
		    break;
		case 'i':
		    SET(rval, (MODE_LOGIN_SHELL | MODE_SHELL));
		    def_env_reset = TRUE;
		    if (excl && excl != 'i')
			usage_excl(1);
		    excl = 'i';
		    break;
		case 'k':
		    rval = MODE_INVALIDATE;
		    if (excl && excl != 'k')
			usage_excl(1);
		    excl = 'k';
		    break;
		case 'K':
		    rval = MODE_KILL;
		    if (excl && excl != 'K')
			usage_excl(1);
		    excl = 'K';
		    break;
		case 'L':
		    rval = MODE_LISTDEFS;
		    if (excl && excl != 'L')
			usage_excl(1);
		    excl = 'L';
		    break;
		case 'l':
		    rval = MODE_LIST;
		    if (excl && excl != 'l')
			usage_excl(1);
		    excl = 'l';
		    break;
		case 'V':
		    rval = MODE_VERSION;
		    if (excl && excl != 'V')
			usage_excl(1);
		    excl = 'V';
		    break;
		case 'h':
		    rval = MODE_HELP;
		    if (excl && excl != 'h')
			usage_excl(1);
		    excl = 'h';
		    break;
		case 's':
		    SET(rval, MODE_SHELL);
		    if (excl && excl != 's')
			usage_excl(1);
		    excl = 's';
		    break;
		case 'H':
		    SET(rval, MODE_RESET_HOME);
		    break;
		case 'P':
		    SET(rval, MODE_PRESERVE_GROUPS);
		    break;
		case 'S':
		    SET(tgetpass_flags, TGP_STDIN);
		    break;
		case 'E':
		    SET(rval, MODE_PRESERVE_ENV);
		    break;
#ifdef HAVE_SELINUX
		case 'r':
		    /* Must have an associated SELinux role. */
		    if (NewArgv[1] == NULL)
			usage(1);

		    user_role = NewArgv[1];

		    NewArgc--;
		    NewArgv++;
		    break;
		case 't':
		    /* Must have an associated SELinux type. */
		    if (NewArgv[1] == NULL)
			usage(1);

		    user_type = NewArgv[1];

		    NewArgc--;
		    NewArgv++;
		    break;
#endif
		case '-':
		    NewArgc--;
		    NewArgv++;
		    goto args_done;
		case '\0':
		    warnx("'-' requires an argument");
		    usage(1);
		default:
		    warnx("illegal option `%s'", NewArgv[0]);
		    usage(1);
	    }
	} else if (NewArgv[0][0] != '/' && strchr(NewArgv[0], '=') != NULL) {
	    /* Could be an environment variable. */
	    struct list_member *ev;
	    ev = emalloc(sizeof(*ev));
	    ev->value = NewArgv[0];
	    ev->next = sudo_user.env_vars;
	    sudo_user.env_vars = ev;
	} else {
	    /* Not an arg */
	    break;
	}
	NewArgc--;
	NewArgv++;
    }
args_done:

    if (ISSET(rval, MODE_EDIT) &&
	(ISSET(rval, MODE_PRESERVE_ENV) || sudo_user.env_vars != NULL)) {
	if (ISSET(rval, MODE_PRESERVE_ENV))
	    warnx("the `-E' option is not valid in edit mode");
	if (sudo_user.env_vars != NULL)
	    warnx("you may not specify environment variables in edit mode");
	usage(1);
    }
    if (ISSET(rval, MODE_PRESERVE_ENV) && ISSET(rval, MODE_LOGIN_SHELL)) {
	warnx("you may not specify both the `-i' and `-E' options");
	usage(1);
    }
    if (user_runas != NULL && !ISSET(rval, (MODE_EDIT|MODE_RUN))) {
	if (excl != '\0')
	    warnx("the `-u' and '-%c' options may not be used together", excl);
	usage(1);
    }
    if ((NewArgc == 0 && (rval & MODE_EDIT)) ||
	(NewArgc > 0 && !(rval & (MODE_RUN | MODE_EDIT))))
	usage(1);
    if (NewArgc == 0 && rval == MODE_RUN)
	SET(rval, (MODE_IMPLIED_SHELL | MODE_SHELL));

    return(rval);
}

/*
 * Sanity check sudoers mode/owner/type.
 * Leaves a file pointer to the sudoers file open in ``fp''.
 */
static void
check_sudoers()
{
    struct stat statbuf;
    int rootstat, i;

    /*
     * Fix the mode and group on sudoers file from old default.
     * Only works if file system is readable/writable by root.
     */
    if ((rootstat = stat_sudoers(_PATH_SUDOERS, &statbuf)) == 0 &&
	SUDOERS_UID == statbuf.st_uid && SUDOERS_MODE != 0400 &&
	(statbuf.st_mode & 0007777) == 0400) {

	if (chmod(_PATH_SUDOERS, SUDOERS_MODE) == 0) {
	    warnx("fixed mode on %s", _PATH_SUDOERS);
	    SET(statbuf.st_mode, SUDOERS_MODE);
	    if (statbuf.st_gid != SUDOERS_GID) {
		if (!chown(_PATH_SUDOERS,(uid_t) -1,SUDOERS_GID)) {
		    warnx("set group on %s", _PATH_SUDOERS);
		    statbuf.st_gid = SUDOERS_GID;
		} else
		    warn("unable to set group on %s", _PATH_SUDOERS);
	    }
	} else
	    warn("unable to fix mode on %s", _PATH_SUDOERS);
    }

    /*
     * Sanity checks on sudoers file.  Must be done as sudoers
     * file owner.  We already did a stat as root, so use that
     * data if we can't stat as sudoers file owner.
     */
    set_perms(PERM_SUDOERS);

    if (rootstat != 0 && stat_sudoers(_PATH_SUDOERS, &statbuf) != 0)
	log_error(USE_ERRNO, "can't stat %s", _PATH_SUDOERS);
    else if (!S_ISREG(statbuf.st_mode))
	log_error(0, "%s is not a regular file", _PATH_SUDOERS);
    else if (statbuf.st_size == 0)
	log_error(0, "%s is zero length", _PATH_SUDOERS);
    else if ((statbuf.st_mode & 07777) != SUDOERS_MODE)
	log_error(0, "%s is mode 0%o, should be 0%o", _PATH_SUDOERS,
	    (unsigned int) (statbuf.st_mode & 07777),
	    (unsigned int) SUDOERS_MODE);
    else if (statbuf.st_uid != SUDOERS_UID)
	log_error(0, "%s is owned by uid %lu, should be %lu", _PATH_SUDOERS,
	    (unsigned long) statbuf.st_uid, (unsigned long) SUDOERS_UID);
    else if (statbuf.st_gid != SUDOERS_GID)
	log_error(0, "%s is owned by gid %lu, should be %lu", _PATH_SUDOERS,
	    (unsigned long) statbuf.st_gid, (unsigned long) SUDOERS_GID);
    else {
	/* Solaris sometimes returns EAGAIN so try 10 times */
	for (i = 0; i < 10 ; i++) {
	    errno = 0;
	    if ((sudoers_fp = fopen(_PATH_SUDOERS, "r")) == NULL ||
		fgetc(sudoers_fp) == EOF) {
		if (sudoers_fp != NULL)
		    fclose(sudoers_fp);
		sudoers_fp = NULL;
		if (errno != EAGAIN && errno != EWOULDBLOCK)
		    break;
	    } else
		break;
	    sleep(1);
	}
	if (sudoers_fp == NULL)
	    log_error(USE_ERRNO, "can't open %s", _PATH_SUDOERS);
    }

    set_perms(PERM_ROOT);		/* change back to root */
}

/*
 * Close all open files (except std*) and turn off core dumps.
 */
static void
initial_setup()
{
    int miss[3], devnull = -1;
#if defined(__linux__) || (defined(RLIMIT_CORE) && !defined(SUDO_DEVEL))
    struct rlimit rl;
#endif

#if defined(__linux__)
    /*
     * Unlimit the number of processes since Linux's setuid() will
     * apply resource limits when changing uid and return EAGAIN if
     * nproc would be violated by the uid switch.
     */
    rl.rlim_cur = rl.rlim_max = RLIM_INFINITY;
    if (setrlimit(RLIMIT_NPROC, &rl)) {
	if (getrlimit(RLIMIT_NPROC, &rl) == 0) {
	    rl.rlim_cur = rl.rlim_max;
	    (void)setrlimit(RLIMIT_NPROC, &rl);
	}
    }
#endif /* __linux__ */
#if defined(RLIMIT_CORE) && !defined(SUDO_DEVEL)
    /*
     * Turn off core dumps.
     */
    (void) getrlimit(RLIMIT_CORE, &corelimit);
    memcpy(&rl, &corelimit, sizeof(struct rlimit));
    rl.rlim_cur = 0;
    (void) setrlimit(RLIMIT_CORE, &rl);
#endif /* RLIMIT_CORE && !SUDO_DEVEL */

    /*
     * stdin, stdout and stderr must be open; set them to /dev/null
     * if they are closed and close all other fds.
     */
    miss[STDIN_FILENO] = fcntl(STDIN_FILENO, F_GETFL, 0) == -1;
    miss[STDOUT_FILENO] = fcntl(STDOUT_FILENO, F_GETFL, 0) == -1;
    miss[STDERR_FILENO] = fcntl(STDERR_FILENO, F_GETFL, 0) == -1;
    if (miss[STDIN_FILENO] || miss[STDOUT_FILENO] || miss[STDERR_FILENO]) {
	if ((devnull = open(_PATH_DEVNULL, O_RDWR, 0644)) != -1) {
	    if (miss[STDIN_FILENO])
		(void) dup2(devnull, STDIN_FILENO);
	    if (miss[STDOUT_FILENO])
		(void) dup2(devnull, STDOUT_FILENO);
	    if (miss[STDERR_FILENO])
		(void) dup2(devnull, STDERR_FILENO);
	}
    }
    closefrom(STDERR_FILENO + 1);
}

#ifdef HAVE_LOGIN_CAP_H
static void
set_loginclass(pw)
    struct passwd *pw;
{
    int errflags;

    /*
     * Don't make it a fatal error if the user didn't specify the login
     * class themselves.  We do this because if login.conf gets
     * corrupted we want the admin to be able to use sudo to fix it.
     */
    if (login_class)
	errflags = NO_MAIL|MSG_ONLY;
    else
	errflags = NO_MAIL|MSG_ONLY|NO_EXIT;

    if (login_class && strcmp(login_class, "-") != 0) {
	if (strcmp(*user_runas, "root") != 0 && user_uid != 0)
	    errx(1, "only root can use -c %s", login_class);
    } else {
	login_class = pw->pw_class;
	if (!login_class || !*login_class)
	    login_class =
		(pw->pw_uid == 0) ? LOGIN_DEFROOTCLASS : LOGIN_DEFCLASS;
    }

    lc = login_getclass(login_class);
    if (!lc || !lc->lc_class || strcmp(lc->lc_class, login_class) != 0) {
	log_error(errflags, "unknown login class: %s", login_class);
	if (!lc)
	    lc = login_getclass(NULL);	/* needed for login_getstyle() later */
    }
}
#else
static void
set_loginclass(pw)
    struct passwd *pw;
{
}
#endif /* HAVE_LOGIN_CAP_H */

#ifdef HAVE_PROJECT_H
static void
set_project(pw)
    struct passwd *pw;
{
    int errflags = NO_MAIL|MSG_ONLY|NO_EXIT;
    int errval;
    struct project proj;
    struct project *resultp = '\0';
    char buf[1024];

    /*
     * Collect the default project for the user and settaskid
     */
    setprojent();
    if (resultp = getdefaultproj(pw->pw_name, &proj, buf, sizeof(buf))) {
	errval = setproject(resultp->pj_name, pw->pw_name, TASK_NORMAL);
	if (errval != 0) {
	    switch(errval) {
	    case SETPROJ_ERR_TASK:
		if (errno == EAGAIN)
		    log_error(errflags, "resource control limit has been reached");
		else if (errno == ESRCH)
		    log_error(errflags, "user \"%s\" is not a member of "
			"project \"%s\"", pw->pw_name, resultp->pj_name);
		else if (errno == EACCES)
		    log_error(errflags, "the invoking task is final");
		else
		    log_error(errflags, "could not join project \"%s\"",
			resultp->pj_name);
		break;
	    case SETPROJ_ERR_POOL:
		if (errno == EACCES)
		    log_error(errflags, "no resource pool accepting "
			    "default bindings exists for project \"%s\"",
			    resultp->pj_name);
		else if (errno == ESRCH)
		    log_error(errflags, "specified resource pool does "
			    "not exist for project \"%s\"", resultp->pj_name);
		else
		    log_error(errflags, "could not bind to default "
			    "resource pool for project \"%s\"", resultp->pj_name);
		break;
	    default:
		if (errval <= 0) {
		    log_error(errflags, "setproject failed for project \"%s\"",
			resultp->pj_name);
		} else {
		    log_error(errflags, "warning, resource control assignment "
			"failed for project \"%s\"", resultp->pj_name);
		}
	    }
	}
    } else {
	log_error(errflags, "getdefaultproj() error: %s", strerror(errno));
    }
    endprojent();
}
#else
static void
set_project(pw)
    struct passwd *pw;
{
}
#endif /* HAVE_PROJECT_H */

/*
 * Look up the fully qualified domain name and set user_host and user_shost.
 */
void
set_fqdn()
{
#ifdef HAVE_GETADDRINFO
    struct addrinfo *res0, hint;
#else
    struct hostent *hp;
#endif
    char *p;

#ifdef HAVE_GETADDRINFO
    memset(&hint, 0, sizeof(hint));
    hint.ai_family = PF_UNSPEC;
    hint.ai_flags = AI_CANONNAME;
    if (getaddrinfo(user_host, NULL, &hint, &res0) != 0) {
#else
    if (!(hp = gethostbyname(user_host))) {
#endif
	log_error(MSG_ONLY|NO_EXIT,
	    "unable to resolve host %s", user_host);
    } else {
	if (user_shost != user_host)
	    efree(user_shost);
	efree(user_host);
#ifdef HAVE_GETADDRINFO
	user_host = estrdup(res0->ai_canonname);
	freeaddrinfo(res0);
#else
	user_host = estrdup(hp->h_name);
#endif
    }
    if ((p = strchr(user_host, '.'))) {
	*p = '\0';
	user_shost = estrdup(user_host);
	*p = '.';
    } else {
	user_shost = user_host;
    }
}

/*
 * Get passwd entry for the user we are going to run commands as.
 * By default, this is "root".  Updates runas_pw as a side effect.
 */
int
set_runaspw(user)
    char *user;
{
    if (runas_pw != NULL) {
	if (user_runas != &def_runas_default)
	    return(TRUE);		/* don't override -u option */
	efree(runas_pw);
    }
    if (*user == '#') {
	runas_pw = sudo_getpwuid(atoi(user + 1));
	if (runas_pw == NULL) {
	    runas_pw = emalloc(sizeof(struct passwd));
	    (void) memset((VOID *)runas_pw, 0, sizeof(struct passwd));
	    runas_pw->pw_uid = atoi(user + 1);
	    runas_pw->pw_name = user;
	    runas_pw->pw_passwd = "*";
	    runas_pw->pw_gecos = user;
	    runas_pw->pw_dir = "/";
	    runas_pw->pw_shell = estrdup(_PATH_BSHELL);
	}
    } else {
	runas_pw = sudo_getpwnam(user);
	if (runas_pw == NULL)
	    log_error(NO_MAIL|MSG_ONLY, "no passwd entry for %s!", user);
    }
    return(TRUE);
}

/*
 * Get passwd entry for the user we are going to authenticate as.
 * By default, this is the user invoking sudo.  In the most common
 * case, this matches sudo_user.pw or runas_pw.
 */
static struct passwd *
get_authpw()
{
    struct passwd *pw;

    if (def_rootpw) {
	if (runas_pw->pw_uid == 0)
	    pw = runas_pw;
	else if ((pw = sudo_getpwuid(0)) == NULL)
	    log_error(0, "uid 0 does not exist in the passwd file!");
    } else if (def_runaspw) {
	if (strcmp(def_runas_default, *user_runas) == 0)
	    pw = runas_pw;
	else if ((pw = sudo_getpwnam(def_runas_default)) == NULL)
	    log_error(0, "user %s does not exist in the passwd file!",
		def_runas_default);
    } else if (def_targetpw) {
	if (runas_pw->pw_name == NULL)
	    log_error(NO_MAIL|MSG_ONLY, "no passwd entry for %lu!",
		(unsigned long) runas_pw->pw_uid);
	pw = runas_pw;
    } else
	pw = sudo_user.pw;

    return(pw);
}

/*
 * Tell which options are mutually exclusive and exit.
 */
static void
usage_excl(exit_val)
    int exit_val;
{
    warnx("Only one of the -e, -h, i, -k, -K, -l, -s, -v or -V options may be used");
    usage(exit_val);
}

/*
 * Give usage message and exit.
 */
static void
usage(exit_val)
    int exit_val;
{
    char **p, **uvec[4];
    int i, linelen, linemax, ulen, plen;
    static char *uvec1[] = {
	" -h |",
	" -K |",
	" -k |",
	" -L |",
	" -l |",
	" -V |",
	" -v",
	NULL
    };
    static char *uvec2[] = {
	" [-bEHPS]",
#ifdef HAVE_BSD_AUTH_H
	" [-a auth_type]",
#endif
#ifdef HAVE_LOGIN_CAP_H
	" [-c class|-]",
#endif
#ifdef HAVE_SELINUX
	" [-r role]",
#endif
	" [-p prompt]",
#ifdef HAVE_SELINUX
	" [-t type]",
#endif
	" [-u username|#uid]",
	" [VAR=value]",
	" {-i | -s | <command>}",
	NULL
    };
    static char *uvec3[] = {
	" -e",
	" [-S]",
#ifdef HAVE_BSD_AUTH_H
	" [-a auth_type]",
#endif
#ifdef HAVE_LOGIN_CAP_H
	" [-c class|-]",
#endif
	" [-p prompt]",
	" [-u username|#uid]",
	" file ...",
	NULL
    };

    /*
     * Use usage vectors appropriate to the progname.
     */
    if (strcmp(getprogname(), "sudoedit") == 0) {
	uvec[0] = uvec3 + 1;
	uvec[1] = NULL;
    } else {
	uvec[0] = uvec1;
	uvec[1] = uvec2;
	uvec[2] = uvec3;
	uvec[3] = NULL;
    }

    /*
     * Print usage and wrap lines as needed.
     * Assumes an 80-character wide terminal, which is kind of bogus...
     */
    ulen = (int)strlen(getprogname()) + 7;
    linemax = 80;
    for (i = 0; uvec[i] != NULL; i++) {
	printf("usage: %s", getprogname());
	linelen = linemax - ulen;
	for (p = uvec[i]; *p != NULL; p++) {
	    plen = (int)strlen(*p);
	    if (linelen >= plen || linelen == linemax - ulen) {
		fputs(*p, stdout);
		linelen -= plen;
	    } else {
		p--;
		linelen = linemax - ulen;
		printf("\n%*s", ulen, "");
	    }
	}
	putchar('\n');
    }
    exit(exit_val);
}