isolate editor variable, only pass line numbers to vi

[unix-history] / usr / src / usr.bin / su / su.c

/*
* Copyright (c) 1988 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)su.c        5.6 (Berkeley) %G%";
#endif /* not lint */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <syslog.h>
#include <stdio.h>
#include <pwd.h>
#include <grp.h>

main(argc, argv)
       int argc;
       char **argv;
{
       extern char **environ;
       extern int errno, optind;
       char *cleanenv[2];
       register struct passwd *pwd;
       register char *p, **g;
       struct group *gr;
       int ch, fulllogin, fastlogin, prio;
       char *user, *shell, *username, nbuf[50];
       char *crypt(), *getpass(), *getenv(), *getlogin(), *strcpy();

       user = "root";
       shell = "/bin/sh";
       fulllogin = fastlogin = 0;

       while ((ch = getopt(argc, argv, "-fl")) != EOF)
               switch((char)ch) {
               case '-':
               case 'l':
                       fulllogin = 1;
                       break;
               case 'f':
                       fastlogin = 1;
                       break;
               case '?':
               default:
                       fprintf(stderr, "usage: su [-fl] [login]\n");
                       exit(1);
               }
       argv += optind;

       if ((pwd = getpwuid(getuid())) == NULL) {
               fprintf(stderr, "su: who are you?\n");
               exit(1);
       }
       username = strcpy(nbuf, pwd->pw_name);

       if (*argv)
               user = *argv++;
       if ((pwd = getpwnam(user)) == NULL) {
               fprintf(stderr, "su: unknown login %s\n", user);
               exit(1);
       }

       /* only allow those in group zero to su to root. */
       if (pwd->pw_uid == 0 && (gr = getgrgid(0)))
               for (g = gr->gr_mem;; ++g) {
                       if (!*g) {
                               fprintf(stderr, "su: you are not in the correct group to su %s.\n", user);
                               exit(1);
                       }
                       if (!strcmp(username, *g))
                               break;
               }

       openlog("su", LOG_ODELAY, LOG_AUTH);

       errno = 0;
       prio = getpriority(PRIO_PROCESS, 0);
       if (errno)
               prio = 0;
       (void)setpriority(PRIO_PROCESS, 0, -2);

       if ((p = getlogin()) && *p)
               username = p;

       if (pwd->pw_passwd[0] && getuid()) {
               p = getpass("Password:");
               if (strcmp(pwd->pw_passwd, crypt(p, pwd->pw_passwd))) {
                       fprintf(stderr, "Sorry\n");
                       if (pwd->pw_uid == 0)
                               syslog(LOG_CRIT, "BAD SU %s on %s",
                                       username, ttyname(2));
                       exit(1);
               }
       }
       if (setgid(pwd->pw_gid) < 0) {
               perror("su: setgid");
               exit(1);
       }
       if (initgroups(user, pwd->pw_gid)) {
               fprintf(stderr, "su: initgroups failed\n");
               exit(1);
       }
       if (setuid(pwd->pw_uid) < 0) {
               perror("su: setuid");
               exit(1);
       }
       if (pwd->pw_shell && *pwd->pw_shell)
               shell = pwd->pw_shell;

       if (fulllogin) {
               p = getenv("TERM");
               cleanenv[0] = "PATH=:/usr/ucb:/bin:/usr/bin";
               cleanenv[1] = NULL;
               environ = cleanenv;
               (void)setenv("TERM", p, 1);
               if (chdir(pwd->pw_dir) < 0) {
                       fprintf(stderr, "su: no directory\n");
                       exit(1);
               }
               (void)setenv("USER", pwd->pw_name, 1);
       }
       else if (strcmp(user, "root"))
               (void)setenv("USER", pwd->pw_name, 1);
       (void)setenv("SHELL", shell, 1);
       (void)setenv("HOME", pwd->pw_dir, 1);

       --argv;
       if (fastlogin)
               *argv-- = "-f";
       *argv = fulllogin ? "-su" : "su";

       if (pwd->pw_uid == 0)
               syslog(LOG_NOTICE, "%s on %s", username, ttyname(2));

       (void)setpriority(PRIO_PROCESS, 0, prio);

       execv(shell, argv);
       fprintf(stderr, "su: no shell\n");
       exit(1);
}