sudo 1.6, now with a BSD license

1 files changed, 1062 insertions, 0 deletions

diff --git a/usr.bin/sudo/sudo.c b/usr.bin/sudo/sudo.c
new file mode 100644
index 00000000000..0a4c908f6ee
--- /dev/null
+++ b/usr.bin/sudo/sudo.c
@@ -0,0 +1,1062 @@
+/*
+ * Copyright (c) 1994-1996,1998-1999 Todd C. Miller <Todd.Miller@courtesan.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * 4. Products derived from this software may not be called "Sudo" nor
+ *    may "Sudo" appear in their names without specific prior written
+ *    permission from the author.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * For a brief history of sudo, please see the HISTORY file included
+ * with this distribution.
+ */
+
+#define _SUDO_SUDO_C
+
+#include "config.h"
+
+#include <stdio.h>
+#ifdef STDC_HEADERS
+#include <stdlib.h>
+#endif /* STDC_HEADERS */
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <pwd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <grp.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#ifdef HAVE_SETRLIMIT
+#include <sys/time.h>
+#include <sys/resource.h>
+#endif
+#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 */
+
+#include "sudo.h"
+#include "interfaces.h"
+#include "version.h"
+
+#ifndef STDC_HEADERS
+extern char *getenv	__P((char *));
+#endif /* STDC_HEADERS */
+
+#ifndef lint
+static const char rcsid[] = "$Sudo: sudo.c,v 1.258 1999/11/16 06:09:23 millert Exp $";
+#endif /* lint */
+
+/*
+ * Local type declarations
+ */
+struct env_table {
+    char *name;
+    int len;
+};
+
+/*
+ * Prototypes
+ */
+static int  parse_args			__P((void));
+static void usage			__P((int));
+static void usage_excl			__P((int));
+static void check_sudoers		__P((void));
+static int init_vars			__P((int));
+static void add_env			__P((int));
+static void clean_env			__P((char **, struct env_table *));
+static void initial_setup		__P((void));
+extern int  user_is_exempt		__P((void));
+extern struct passwd *sudo_getpwuid	__P((uid_t));
+extern void list_matches		__P((void));
+
+/*
+ * Globals
+ */
+int Argc;
+char **Argv;
+int NewArgc = 0;
+char **NewArgv = NULL;
+struct sudo_user sudo_user;
+FILE *sudoers_fp = NULL;
+static char *runas_homedir = NULL;	/* XXX */
+struct interface *interfaces;
+int num_interfaces;
+extern int errorlineno;
+
+/*
+ * Table of "bad" envariables to remove and len for strncmp()
+ */
+static struct env_table badenv_table[] = {
+    { "IFS=", 4 },
+    { "LOCALDOMAIN=", 12 },
+    { "RES_OPTIONS=", 12 },
+    { "HOSTALIASES=", 12 },
+    { "LD_", 3 },
+    { "_RLD", 4 },
+#ifdef __hpux
+    { "SHLIB_PATH=", 11 },
+#endif /* __hpux */
+#ifdef _AIX
+    { "LIBPATH=", 8 },
+#endif /* _AIX */
+#ifdef HAVE_KERB4
+    { "KRB_CONF", 8 },
+#endif /* HAVE_KERB4 */
+#ifdef HAVE_KERB5
+    { "KRB5_CONFIG", 11 },
+#endif /* HAVE_KERB5 */
+    { "ENV=", 4 },
+    { "BASH_ENV=", 9 },
+    { (char *) NULL, 0 }
+};
+
+
+int
+main(argc, argv)
+    int argc;
+    char **argv;
+{
+    int validated;
+    int fd;
+    int cmnd_status;
+    int sudo_mode;
+#ifdef POSIX_SIGNALS
+    sigset_t set, oset;
+#else
+    int omask;
+#endif /* POSIX_SIGNALS */
+    extern char **environ;
+    extern int printmatches;
+
+    /* 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 */
+
+    Argv = argv;
+    Argc = argc;
+
+    if (geteuid() != 0) {
+	(void) fprintf(stderr, "Sorry, %s must be setuid root.\n", Argv[0]);
+	exit(1);
+    }
+
+    /*
+     * Block signals so the user cannot interrupt us at some point and
+     * avoid the logging.
+     */
+#ifdef POSIX_SIGNALS
+    (void) sigemptyset(&set);
+    (void) sigaddset(&set, SIGINT);
+    (void) sigaddset(&set, SIGQUIT);
+    (void) sigaddset(&set, SIGTSTP);
+    (void) sigprocmask(SIG_BLOCK, &set, &oset);
+#else
+    omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGTSTP));
+#endif /* POSIX_SIGNALS */
+
+    /*
+     * Setup signal handlers, turn off core dumps, and close open files.
+     */
+    initial_setup();
+
+    /*
+     * Set the prompt based on $SUDO_PROMPT (can be overridden by `-p')
+     */
+    user_prompt = getenv("SUDO_PROMPT");
+
+    /* Parse our arguments. */
+    sudo_mode = parse_args();
+
+    /* Setup defaults data structures. */
+    init_defaults();
+
+    /* Initialize syslog(3) if we are using it. */
+    if (def_str(I_LOGFACSTR)) {
+#ifdef LOG_NFACILITIES
+	openlog("sudo", 0, def_ival(I_LOGFAC));
+#else
+	openlog("sudo", 0);
+#endif /* LOG_NFACILITIES */
+    }
+
+    if (sudo_mode & MODE_SHELL)
+	user_cmnd = "shell";
+    else
+	switch (sudo_mode) {
+	    case MODE_VERSION:
+		(void) printf("Sudo version %s\n", version);
+		if (getuid() == 0) {
+		    putchar('\n');
+		    dump_auth_methods();
+		    dump_defaults();
+		}
+		exit(0);
+		break;
+	    case MODE_HELP:
+		usage(0);
+		break;
+	    case MODE_VALIDATE:
+		user_cmnd = "validate";
+		break;
+	    case MODE_KILL:
+	    case MODE_INVALIDATE:
+		user_cmnd = "kill";
+		break;
+	    case MODE_LISTDEFS:
+		list_options();
+		exit(0);
+		break;
+	    case MODE_LIST:
+		user_cmnd = "list";
+		printmatches = 1;
+		break;
+	}
+
+    /* Must have a command to run... */
+    if (user_cmnd == NULL && NewArgc == 0)
+	usage(1);
+
+    clean_env(environ, badenv_table);
+
+    cmnd_status = init_vars(sudo_mode);
+
+    /* At this point, ruid == euid == 0 */
+
+    check_sudoers();	/* check mode/owner on _PATH_SUDOERS */
+
+    if (sudo_mode == MODE_KILL || sudo_mode == MODE_INVALIDATE) {
+	remove_timestamp((sudo_mode == MODE_KILL));
+	exit(0);
+    }
+
+    add_env(!(sudo_mode & MODE_SHELL));	/* add in SUDO_* envariables */
+
+    /* Validate the user but don't search for pseudo-commands. */
+    validated =
+	sudoers_lookup((sudo_mode != MODE_VALIDATE && sudo_mode != MODE_LIST));
+
+    if (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_flag(I_ROOT_SUDO)) {
+	(void) fputs("You are already root, you don't need to use sudo.\n",
+	    stderr);
+	exit(1);
+    }
+
+    /* Bail if a tty is required and we don't have one.  */
+    if (def_flag(I_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);
+    }
+
+    /* Require a password unless the NOPASS tag was set.  */
+    if (!(validated & FLAG_NOPASS))
+	check_user();
+
+    if (validated & VALIDATE_OK) {
+	/* Finally tell the user if the command did not exist. */
+	if (cmnd_status == NOT_FOUND_DOT) {
+	    (void) fprintf(stderr, "%s: ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.\n", Argv[0], user_cmnd, user_cmnd, user_cmnd);
+	    exit(1);
+	} else if (cmnd_status == NOT_FOUND) {
+	    (void) fprintf(stderr, "%s: %s: command not found\n", Argv[0],
+		user_cmnd);
+	    exit(1);
+	}
+
+	log_auth(validated, 1);
+	if (sudo_mode == MODE_VALIDATE)
+	    exit(0);
+	else if (sudo_mode == MODE_LIST) {
+	    list_matches();
+	    exit(0);
+	}
+
+	/* Become specified user or root. */
+	set_perms(PERM_RUNAS, sudo_mode);
+
+	/* Set $HOME for `sudo -H' */
+	if ((sudo_mode & MODE_RESET_HOME) && runas_homedir)
+	    (void) sudo_setenv("HOME", runas_homedir);
+
+	/* This *must* have been set if we got a match but... */
+	if (safe_cmnd == NULL) {
+	    log_error(MSG_ONLY,
+		"internal error, cmnd_safe never got set for %s; %s",
+		user_cmnd,
+		"please report this error at http://courtesan.com/sudo/bugs/");
+	}
+
+	if (def_ival(I_LOGFACSTR))
+	    closelog();
+
+	/* Reset signal mask before we exec. */
+#ifdef POSIX_SIGNALS
+	(void) sigprocmask(SIG_SETMASK, &oset, NULL);
+#else
+	(void) sigsetmask(omask);
+#endif /* POSIX_SIGNALS */
+
+	/* Override user's umask if configured to do so. */
+	if (def_ival(I_UMASK) != 0777)
+	    (void) umask(def_mode(I_UMASK));
+
+	/* Replace the PATH envariable with a secure one. */
+	if (def_str(I_SECURE_PATH) && !user_is_exempt())
+	    if (sudo_setenv("PATH", def_str(I_SECURE_PATH))) {
+		(void) fprintf(stderr, "%s: cannot allocate memory!\n",
+		    Argv[0]);
+		exit(1);
+	    }
+
+#ifndef PROFILING
+	if ((sudo_mode & MODE_BACKGROUND) && fork() > 0)
+	    exit(0);
+	else
+	    EXEC(safe_cmnd, NewArgv);	/* run the command */
+#else
+	exit(0);
+#endif /* PROFILING */
+	/*
+	 * If we got here then the exec() failed...
+	 */
+	(void) fprintf(stderr, "%s: unable to exec %s: %s\n",
+	    Argv[0], safe_cmnd, strerror(errno));
+	exit(-1);
+    } else if ((validated & FLAG_NO_USER) || (validated & FLAG_NO_HOST)) {
+	log_auth(validated, 1);
+	exit(1);
+    } else if (validated & VALIDATE_NOT_OK) {
+	if (def_flag(I_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)
+		(void) fprintf(stderr, "%s: %s: command not found\n", Argv[0],
+		    user_cmnd);
+	    else if (cmnd_status == NOT_FOUND_DOT)
+		(void) fprintf(stderr, "%s: ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.\n", Argv[0], 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)
+    int sudo_mode;
+{
+    char *p, thost[MAXHOSTNAMELEN];
+    struct hostent *hp;
+
+    /* Sanity check command from user. */
+    if (user_cmnd == NULL && strlen(NewArgv[0]) >= MAXPATHLEN) {
+	(void) fprintf(stderr, "%s: %s: Pathname too long\n", Argv[0],
+	    NewArgv[0]);
+	exit(1);
+    }
+
+#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) strcpy(user_cwd, "unknown");
+
+    /*
+     * 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.
+     */
+    if ((gethostname(thost, sizeof(thost)))) {
+	user_host = "localhost";
+	log_error(USE_ERRNO|MSG_ONLY, "can't get hostname");
+    } else
+	user_host = estrdup(thost);
+    if (def_flag(I_FQDN)) {
+	if (!(hp = gethostbyname(user_host))) {
+	    log_error(USE_ERRNO|MSG_ONLY|NO_EXIT,
+		"unable to lookup %s via gethostbyname()", user_host);
+	} else {
+	    free(user_host);
+	    user_host = estrdup(hp->h_name);
+	}
+    }
+    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))) {
+	if (strncmp(p, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
+	    p += sizeof(_PATH_DEV) - 1;
+	user_tty = estrdup(p);
+    } else
+	user_tty = "unknown";
+
+    /*
+     * 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) sprintf(pw_name, "%ld", (long) pw.pw_uid);
+	pw.pw_name = pw_name;
+	sudo_user.pw = &pw;
+
+	log_error(0, "uid %ld does not exist in the passwd file!",
+	    (long) pw.pw_uid);
+    }
+
+    /* It is now safe to use log_error() and set_perms() */
+
+    /*
+     * Get current working directory.  Try as user, fall back to root.
+     */
+    set_perms(PERM_USER, sudo_mode);
+    if (!getcwd(user_cwd, sizeof(user_cwd))) {
+	set_perms(PERM_ROOT, sudo_mode);
+	if (!getcwd(user_cwd, sizeof(user_cwd))) {
+	    (void) fprintf(stderr, "%s: Can't get working directory!\n",
+			   Argv[0]);
+	    (void) strcpy(user_cwd, "unknown");
+	}
+    } else
+	set_perms(PERM_ROOT, sudo_mode);
+
+    /*
+     * Load the list of local ip addresses and netmasks into
+     * the interfaces array.
+     */
+    load_interfaces();
+
+    /*
+     * If we were given the '-s' option (run shell) we need to redo
+     * NewArgv and NewArgc.
+     */
+    if ((sudo_mode & MODE_SHELL)) {
+	char **dst, **src = NewArgv;
+
+	NewArgv = (char **) emalloc (sizeof(char *) * (++NewArgc + 1));
+	if (user_shell && *user_shell) {
+	    NewArgv[0] = user_shell;
+	} else {
+	    (void) fprintf(stderr, "%s: Unable to determine shell.", Argv[0]);
+	    exit(1);
+	}
+
+	/* copy the args from Argv */
+	for (dst = NewArgv + 1; (*dst = *src) != NULL; ++src, ++dst)
+	    ;
+    }
+
+    /* Resolve the path and return. */
+    if ((sudo_mode & MODE_RUN))
+	return(find_path(NewArgv[0], &user_cmnd));
+    else
+	return(FOUND);
+}
+
+/*
+ * Command line argument parsing, can't use getopt(3).
+ */
+static int
+parse_args()
+{
+    int rval = MODE_RUN;		/* what mode is suod to be run in? */
+    int excl = 0;			/* exclusive arg, no others allowed */
+
+    NewArgv = Argv + 1;
+    NewArgc = Argc - 1;
+
+    if (Argc < 2) {			/* no options and no command */
+	if (!def_flag(I_SHELL_NOARGS))
+	    usage(1);
+	rval |= MODE_SHELL;
+	return(rval);
+    }
+
+    while (NewArgc > 0 && NewArgv[0][0] == '-') {
+	if (NewArgv[0][1] != '\0' && NewArgv[0][2] != '\0') {
+	    (void) fprintf(stderr, "%s: Please use single character options\n",
+		Argv[0]);
+	    usage(1);
+	}
+
+	switch (NewArgv[0][1]) {
+	    case 'p':
+		/* Must have an associated prompt. */
+		if (NewArgv[1] == NULL)
+		    usage(1);
+
+		user_prompt = NewArgv[1];
+
+		/* Shift Argv over and adjust Argc. */
+		NewArgc--;
+		NewArgv++;
+		break;
+	    case 'u':
+		/* Must have an associated runas user. */
+		if (NewArgv[1] == NULL)
+		    usage(1);
+
+		user_runas = &NewArgv[1];
+
+		/* Shift Argv over and adjust Argc. */
+		NewArgc--;
+		NewArgv++;
+		break;
+	    case 'b':
+		rval |= MODE_BACKGROUND;
+		break;
+	    case 'v':
+		rval = MODE_VALIDATE;
+		if (excl && excl != 'v')
+		    usage_excl(1);
+		excl = 'v';
+		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':
+		rval |= MODE_SHELL;
+		if (def_flag(I_SET_HOME))
+		    rval |= MODE_RESET_HOME;
+		break;
+	    case 'H':
+		rval |= MODE_RESET_HOME;
+		break;
+	    case '-':
+		NewArgc--;
+		NewArgv++;
+		if (def_flag(I_SHELL_NOARGS) && rval == MODE_RUN)
+		    rval |= MODE_SHELL;
+		return(rval);
+	    case '\0':
+		(void) fprintf(stderr, "%s: '-' requires an argument\n",
+		    Argv[0]);
+		usage(1);
+	    default:
+		(void) fprintf(stderr, "%s: Illegal option %s\n", Argv[0],
+		    NewArgv[0]);
+		usage(1);
+	}
+	NewArgc--;
+	NewArgv++;
+    }
+
+    if (NewArgc > 0 && !(rval & MODE_RUN))
+	usage(1);
+
+    return(rval);
+}
+
+/*
+ * Add sudo-specific variables into the environment.
+ * Sets ``cmnd_args'' as a side effect.
+ */
+static void
+add_env(contiguous)
+    int contiguous;
+{
+    char idstr[MAX_UID_T_LEN + 1];
+    size_t size;
+    char *buf;
+
+    /* Add the SUDO_COMMAND envariable (cmnd + args). */
+    size = strlen(user_cmnd) + 1;
+    if (NewArgc > 1) {
+	char *to, **from;
+
+	if (contiguous) {
+	    size += (size_t) (NewArgv[NewArgc-1] - NewArgv[1]) +
+		    strlen(NewArgv[NewArgc-1]) + 1;
+	} else {
+	    for (from = &NewArgv[1]; *from; from++)
+		size += strlen(*from) + 1;
+	}
+
+	buf = (char *) emalloc(size);
+
+	/*
+	 * Copy the command and it's arguments info buf.
+	 */
+	(void) strcpy(buf, user_cmnd);
+	to = buf + strlen(user_cmnd);
+	for (from = &NewArgv[1]; *from; from++) {
+	    *to++ = ' ';
+	    (void) strcpy(to, *from);
+	    to += strlen(*from);
+	}
+    } else {
+	buf = user_cmnd;
+    }
+    if (sudo_setenv("SUDO_COMMAND", buf)) {
+	(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
+	exit(1);
+    }
+    if (NewArgc > 1)
+	free(buf);
+
+    /* Grab a pointer to the flat arg string from the environment. */
+    if (NewArgc > 1 && (user_args = getenv("SUDO_COMMAND"))) {
+	if ((user_args = strchr(user_args, ' ')))
+	    user_args++;
+	else
+	    user_args = NULL;
+    }
+
+    /* Add the SUDO_USER environment variable. */
+    if (sudo_setenv("SUDO_USER", user_name)) {
+	(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
+	exit(1);
+    }
+
+    /* Add the SUDO_UID environment variable. */
+    (void) sprintf(idstr, "%ld", (long) user_uid);
+    if (sudo_setenv("SUDO_UID", idstr)) {
+	(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
+	exit(1);
+    }
+
+    /* Add the SUDO_GID environment variable. */
+    (void) sprintf(idstr, "%ld", (long) user_gid);
+    if (sudo_setenv("SUDO_GID", idstr)) {
+	(void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
+	exit(1);
+    }
+
+    /* Set PS1 if SUDO_PS1 is set. */
+    if ((buf = getenv("SUDO_PS1")))
+	if (sudo_setenv("PS1", buf)) {
+	    (void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
+	    exit(1);
+	}
+}
+
+/*
+ * 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;
+    char c;
+
+    /*
+     * Fix the mode and group on sudoers file from old default.
+     * Only works if filesystem is readable/writable by root.
+     */
+    if ((rootstat = lstat(_PATH_SUDOERS, &statbuf)) == 0 &&
+	SUDOERS_UID == statbuf.st_uid && SUDOERS_MODE != 0400 &&
+	(statbuf.st_mode & 0007777) == 0400) {
+
+	if (chmod(_PATH_SUDOERS, SUDOERS_MODE) == 0) {
+	    (void) fprintf(stderr, "%s: fixed mode on %s\n",
+		Argv[0], _PATH_SUDOERS);
+	    if (statbuf.st_gid != SUDOERS_GID) {
+		if (!chown(_PATH_SUDOERS,(uid_t) -1,SUDOERS_GID)) {
+		    (void) fprintf(stderr, "%s: set group on %s\n",
+			Argv[0], _PATH_SUDOERS);
+		    statbuf.st_gid = SUDOERS_GID;
+		} else {
+		    (void) fprintf(stderr,"%s: Unable to set group on %s: %s\n",
+			Argv[0], _PATH_SUDOERS, strerror(errno));
+		}
+	    }
+	} else {
+	    (void) fprintf(stderr, "%s: Unable to fix mode on %s: %s\n",
+		Argv[0], _PATH_SUDOERS, strerror(errno));
+	}
+    }
+
+    /*
+     * 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, 0);
+
+    if (rootstat != 0 && lstat(_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_mode & 07777) != SUDOERS_MODE)
+	log_error(0, "%s is mode 0%o, should be 0%o", _PATH_SUDOERS,
+	    (statbuf.st_mode & 07777), SUDOERS_MODE);
+    else if (statbuf.st_uid != SUDOERS_UID)
+	log_error(0, "%s is owned by uid %ld, should be %d", _PATH_SUDOERS,
+	    (long) statbuf.st_uid, SUDOERS_UID);
+    else if (statbuf.st_gid != SUDOERS_GID)
+	log_error(0, "%s is owned by gid %ld, should be %d", _PATH_SUDOERS,
+	    (long) statbuf.st_gid, 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 ||
+		fread(&c, sizeof(c), 1, sudoers_fp) != 1) {
+		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, 0);		/* change back to root */
+}
+
+/*
+ * Remove environment variables that match the entries in badenv_table.
+ */
+static void
+clean_env(envp, badenv_table)
+    char **envp;
+    struct env_table *badenv_table;
+{
+    struct env_table *bad;
+    char **cur;
+
+    /*
+     * Remove any envars that match entries in badenv_table.
+     */
+    for (cur = envp; *cur; cur++) {
+	for (bad = badenv_table; bad->name; bad++) {
+	    if (strncmp(*cur, bad->name, bad->len) == 0) {
+		/* Got a match so remove it. */
+		char **move;
+
+		for (move = cur; *move; move++)
+		    *move = *(move + 1);
+
+		cur--;
+
+		break;
+	    }
+	}
+    }
+}
+
+/*
+ * Set real and effective uids and gids based on perm.
+ */
+void
+set_perms(perm, sudo_mode)
+    int perm;
+    int sudo_mode;
+{
+    struct passwd *pw;
+
+    /*
+     * First, set real & effective uids to root.
+     * If perm is PERM_ROOT then we don't need to do anything else.
+     */
+    if (setuid(0)) {
+	perror("setuid(0)");
+	exit(1);
+    }
+
+    switch (perm) {
+	case PERM_USER:
+    	    	    	        (void) setgid(user_gid);
+
+    	    	    	        if (seteuid(user_uid)) {
+    	    	    	            perror("seteuid(user_uid)");
+    	    	    	            exit(1);
+    	    	    	        }
+			      	break;
+				
+	case PERM_FULL_USER:
+    	    	    	        (void) setgid(user_gid);
+
+				if (setuid(user_uid)) {
+				    perror("setuid(user_uid)");
+				    exit(1);
+				}
+			      	break;
+
+	case PERM_RUNAS:
+				/* XXX - add group/gid support */
+				if (**user_runas == '#') {
+				    if (setuid(atoi(*user_runas + 1))) {
+					(void) fprintf(stderr,
+					    "%s: cannot set uid to %s: %s\n",
+					    Argv[0], *user_runas, strerror(errno));
+					exit(1);
+				    }
+				} else {
+				    if (!(pw = getpwnam(*user_runas))) {
+					(void) fprintf(stderr,
+					    "%s: no passwd entry for %s!\n",
+					    Argv[0], *user_runas);
+					exit(1);
+				    }
+
+				    /* Set $USER and $LOGNAME to target user */
+				    if (sudo_setenv("USER", pw->pw_name)) {
+					(void) fprintf(stderr,
+					    "%s: cannot allocate memory!\n",
+					    Argv[0]);
+					exit(1);
+				    }
+				    if (sudo_setenv("LOGNAME", pw->pw_name)) {
+					(void) fprintf(stderr,
+					    "%s: cannot allocate memory!\n",
+					    Argv[0]);
+					exit(1);
+				    }
+
+				    if (setgid(pw->pw_gid)) {
+					(void) fprintf(stderr,
+					    "%s: cannot set gid to %ld: %s\n",
+					    Argv[0], (long) pw->pw_gid,
+					    strerror(errno));
+					exit(1);
+				    }
+
+				    /*
+				     * Initialize group vector only if are
+				     * going to run as a non-root user.
+				     */
+				    if (strcmp(*user_runas, "root") != 0 &&
+					initgroups(*user_runas, pw->pw_gid)
+					== -1) {
+					(void) fprintf(stderr,
+					    "%s: cannot set group vector: %s\n",
+					    Argv[0], strerror(errno));
+					exit(1);
+				    }
+
+				    if (setuid(pw->pw_uid)) {
+					(void) fprintf(stderr,
+					    "%s: cannot set uid to %ld: %s\n",
+					    Argv[0], (long) pw->pw_uid,
+					    strerror(errno));
+					exit(1);
+				    }
+				    if (sudo_mode & MODE_RESET_HOME)
+					runas_homedir = pw->pw_dir;
+				}
+				break;
+
+	case PERM_SUDOERS:
+				if (setgid(SUDOERS_GID)) {
+				    perror("setgid(SUDOERS_GID)");
+				    exit(1);
+				}
+
+				/*
+				 * If SUDOERS_UID == 0 and SUDOERS_MODE
+				 * is group readable we use a non-zero
+				 * uid in order to avoid NFS lossage.
+				 * Using uid 1 is a bit bogus but should
+				 * work on all OS's.
+				 */
+				if (SUDOERS_UID == 0) {
+				    if ((SUDOERS_MODE & 040) && seteuid(1)) {
+					perror("seteuid(1)");
+					exit(1);
+				    }
+				} else {
+				    if (seteuid(SUDOERS_UID)) {
+					perror("seteuid(SUDOERS_UID)");
+					exit(1);
+				    }
+				}
+			      	break;
+    }
+}
+
+/*
+ * Close all open files (except std*) and turn off core dumps.
+ */
+static void
+initial_setup()
+{
+    int fd, maxfd;
+#ifdef HAVE_SETRLIMIT
+    struct rlimit rl;
+#endif
+#ifdef POSIX_SIGNALS
+    struct sigaction sa;
+#endif
+
+#if defined(RLIMIT_CORE) && !defined(SUDO_DEVEL)
+    /*
+     * Turn off core dumps.
+     */
+    rl.rlim_cur = rl.rlim_max = 0;
+    (void) setrlimit(RLIMIT_CORE, &rl);
+#endif /* RLIMIT_CORE */
+
+    /*
+     * Close any open fd's other than stdin, stdout and stderr.
+     */
+#ifdef RLIMIT_NOFILE
+    if (getrlimit(RLIMIT_NOFILE, &rl) == 0)
+	maxfd = rl.rlim_max - 1;
+    else
+#endif /* RLIMIT_NOFILE */
+#ifdef HAVE_SYSCONF
+	maxfd = sysconf(_SC_OPEN_MAX) - 1;
+#else
+	maxfd = getdtablesize() - 1;
+#endif /* HAVE_SYSCONF */
+
+    for (fd = maxfd; fd > STDERR_FILENO; fd--)
+	(void) close(fd);
+
+    /* Catch children as they die... */
+#ifdef POSIX_SIGNALS
+    (void) memset((VOID *)&sa, 0, sizeof(sa));
+    sa.sa_handler = reapchild;
+    (void) sigaction(SIGCHLD, &sa, NULL);
+#else
+    (void) signal(SIGCHLD, reapchild);
+#endif /* POSIX_SIGNALS */
+}
+
+/*
+ * Tell which options are mutually exclusive and exit.
+ */
+static void
+usage_excl(exit_val)
+    int exit_val;
+{
+    (void) fprintf(stderr,
+	"Only one of the -v, -k, -K, -l, -V and -h options may be used\n");
+    usage(exit_val);
+}
+
+/*
+ * Give usage message and exit.
+ */
+static void
+usage(exit_val)
+    int exit_val;
+{
+    (void) fprintf(stderr,
+	"usage: %s -V | -h | -L | -l | -v | -k | -K | -H | [-b] [-p prompt]\n%*s",
+	Argv[0], (int) strlen(Argv[0]) + 8, " ");
+    (void) fprintf(stderr, "[-u username/#uid] -s | <command>\n");
+    exit(exit_val);
+}