Add spl's around queue manipulation

[unix-history] / usr / src / usr.bin / passwd / chsh.sh

#ifndef lint
static char *sccsid = "@(#)chsh.sh      4.9 (Berkeley) %G%";
#endif

/*
* chsh
*/
#include <stdio.h>
#include <signal.h>
#include <pwd.h>
#include <ndbm.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/resource.h>

char    temp[] = "/etc/ptmp";
char    passwd[] = "/etc/passwd";
struct  passwd *pwd;
struct  passwd *getpwent();
int     endpwent();
char    *crypt();
char    *getpass();
char    *strcat();
char    buf[BUFSIZ];

main(argc, argv)
register char *argv[];
{
       register int u, fd;
       register FILE *tf;
       DBM *dp;

       if (argc < 2 || argc > 3) {
               printf("Usage: chsh user [ /bin/csh ]\n");
               exit(1);
       }
       if (argc == 2)
               argv[2] = "";
       else {
               if (argv[2][0] != '/')
                       argv[2] = strcat(
                           "/bin/\0 12345678901234567890123456789", argv[2]);
               if (strcmp(argv[2], "/bin/csh") &&
                   strcmp(argv[2], "/bin/oldcsh") &&
                   strcmp(argv[2], "/bin/newcsh") &&
                   strcmp(argv[2], "/usr/new/csh") &&
                       /* and, for cretins who can't read the manual */
                   strcmp(argv[2], "/bin/sh") &&
                   getuid()) {
                       printf(
                           "Only /bin/csh may be specified\n"
                       );
                       exit(1);
               }
               if (access(argv[2], 1) < 0) {
                       printf("%s is not available\n", argv[2]);
                       exit(1);
               }
       }
       unlimit(RLIMIT_CPU);
       unlimit(RLIMIT_FSIZE);
       u = getuid();
       if (u != 0 && ((pwd = getpwnam(argv[1])) == NULL || u != pwd->pw_uid)) {
               printf("Permission denied.\n");
               exit(1);
       }

       signal(SIGHUP, SIG_IGN);
       signal(SIGINT, SIG_IGN);
       signal(SIGQUIT, SIG_IGN);
       signal(SIGTSTP, SIG_IGN);
       (void) umask(0);
       if ((fd = open(temp, O_CREAT|O_EXCL|O_RDWR, 0644)) < 0) {
               printf("Temporary file busy -- try again\n");
               exit(1);
       }
       if ((tf = fdopen(fd, "w")) == NULL) {
               printf("Absurd fdopen failure - seek help\n");
               goto out;
       }
       if ((dp = ndbmopen(passwd, O_RDWR, 0644)) == NULL) {
               fprintf(stderr, "Warning: dbminit failed: ");
               perror(passwd);
       } else if (flock(dp->db_dirf, LOCK_EX) < 0) {
               perror("Warning: lock failed");
               ndbmclose(dp);
               dp = NULL;
       }
       /*
        * Copy passwd to temp, replacing matching lines
        * with new shell.
        */
       while ((pwd = getpwent()) != NULL) {
               if (strcmp(pwd->pw_name, argv[1]) == 0) {
                       if (u != 0 && u != pwd->pw_uid) {
                               printf("Permission denied.\n");
                               goto out;
                       }
                       pwd->pw_shell = argv[2];
                       replace(dp, pwd);
               }
               if (strcmp(pwd->pw_shell, "/bin/sh") == 0)
                       pwd->pw_shell = "";
               fprintf(tf, "%s:%s:%d:%d:%s:%s:%s\n"
                       , pwd->pw_name
                       , pwd->pw_passwd
                       , pwd->pw_uid
                       , pwd->pw_gid
                       , pwd->pw_gecos
                       , pwd->pw_dir
                       , pwd->pw_shell
               );
       }
       endpwent();
       (void) fclose(tf);
       ndbmclose(dp);
       if (rename(temp, passwd) < 0) {
               fprintf(stderr, "chsh: "), perror("rename");
       out:
               (void) unlink(temp);
               exit(1);
       }
       exit(0);
}

unlimit(lim)
{
       struct rlimit rlim;

       rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
       setrlimit(lim, &rlim);
}

/*
* Replace the password entry in the dbm data base with pwd.
*/
replace(dp, pwd)
       DBM *dp;
       struct passwd *pwd;
{
       datum key, content;
       register char *cp, *tp;
       char buf[BUFSIZ];

       if (dp == NULL)
               return;

       cp = buf;
#define COMPACT(e)      tp = pwd->pw_/**/e; while (*cp++ = *tp++);
       COMPACT(name);
       COMPACT(passwd);
       *(int *)cp = pwd->pw_uid; cp += sizeof (int);
       *(int *)cp = pwd->pw_gid; cp += sizeof (int);
       *(int *)cp = pwd->pw_quota; cp += sizeof (int);
       COMPACT(comment);
       COMPACT(gecos);
       COMPACT(dir);
       COMPACT(shell);
       content.dptr = buf;
       content.dsize = cp - buf;
       key.dptr = pwd->pw_name;
       key.dsize = strlen(pwd->pw_name);
       dbmstore(dp, key, content, DB_REPLACE);
       key.dptr = (char *)&pwd->pw_uid;
       key.dsize = sizeof (int);
       dbmstore(dp, key, content, DB_REPLACE);
}