UNIX 7th Ed. - /usr/src/cmd/login.c

   1: /*
   2:  * login [ name ]
   3:  */
   4: 
   5: #include <sys/types.h>
   6: #include <sgtty.h>
   7: #include <utmp.h>
   8: #include <signal.h>
   9: #include <pwd.h>
  10: #include <stdio.h>
  11: #include <sys/stat.h>
  12: #define SCPYN(a, b) strncpy(a, b, sizeof(a))
  13: 
  14: char    maildir[30] =   "/usr/spool/mail/";
  15: struct  passwd nouser = {"", "nope"};
  16: struct  sgttyb ttyb;
  17: struct  utmp utmp;
  18: char    minusnam[16] = "-";
  19: char    homedir[64] = "HOME=";
  20: char    *envinit[] = {homedir, "PATH=:/bin:/usr/bin", 0};
  21: struct  passwd *pwd;
  22: 
  23: struct  passwd *getpwnam();
  24: char    *strcat();
  25: int setpwent();
  26: char    *ttyname();
  27: char    *crypt();
  28: char    *getpass();
  29: char    *rindex(), *index();
  30: extern  char **environ;
  31: 
  32: main(argc, argv)
  33: char **argv;
  34: {
  35:     register char *namep;
  36:     int t, f, c;
  37:     char *ttyn;
  38: 
  39:     alarm(60);
  40:     signal(SIGQUIT, SIG_IGN);
  41:     signal(SIGINT, SIG_IGN);
  42:     nice(-100);
  43:     nice(20);
  44:     nice(0);
  45:     gtty(0, &ttyb);
  46:     ttyb.sg_erase = '#';
  47:     ttyb.sg_kill = '@';
  48:     stty(0, &ttyb);
  49:     for (t=3; t<20; t++)
  50:         close(t);
  51:     ttyn = ttyname(0);
  52:     if (ttyn==0)
  53:         ttyn = "/dev/tty??";
  54: 
  55:     loop:
  56:     SCPYN(utmp.ut_name, "");
  57:     if (argc>1) {
  58:         SCPYN(utmp.ut_name, argv[1]);
  59:         argc = 0;
  60:     }
  61:     while (utmp.ut_name[0] == '\0') {
  62:         namep = utmp.ut_name;
  63:         printf("login: ");
  64:         while ((c = getchar()) != '\n') {
  65:             if(c == ' ')
  66:                 c = '_';
  67:             if (c == EOF)
  68:                 exit(0);
  69:             if (namep < utmp.ut_name+8)
  70:                 *namep++ = c;
  71:         }
  72:     }
  73:     setpwent();
  74:     if ((pwd = getpwnam(utmp.ut_name)) == NULL)
  75:         pwd = &nouser;
  76:     endpwent();
  77:     if (*pwd->pw_passwd != '\0') {
  78:         namep = crypt(getpass("Password:"),pwd->pw_passwd);
  79:         if (strcmp(namep, pwd->pw_passwd)) {
  80:             printf("Login incorrect\n");
  81:             goto loop;
  82:         }
  83:     }
  84:     if(chdir(pwd->pw_dir) < 0) {
  85:         printf("No directory\n");
  86:         goto loop;
  87:     }
  88:     time(&utmp.ut_time);
  89:     t = ttyslot();
  90:     if (t>0 && (f = open("/etc/utmp", 1)) >= 0) {
  91:         lseek(f, (long)(t*sizeof(utmp)), 0);
  92:         SCPYN(utmp.ut_line, index(ttyn+1, '/')+1);
  93:         write(f, (char *)&utmp, sizeof(utmp));
  94:         close(f);
  95:     }
  96:     if (t>0 && (f = open("/usr/adm/wtmp", 1)) >= 0) {
  97:         lseek(f, 0L, 2);
  98:         write(f, (char *)&utmp, sizeof(utmp));
  99:         close(f);
 100:     }
 101:     chown(ttyn, pwd->pw_uid, pwd->pw_gid);
 102:     setgid(pwd->pw_gid);
 103:     setuid(pwd->pw_uid);
 104:     if (*pwd->pw_shell == '\0')
 105:         pwd->pw_shell = "/bin/sh";
 106:     environ = envinit;
 107:     strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
 108:     if ((namep = rindex(pwd->pw_shell, '/')) == NULL)
 109:         namep = pwd->pw_shell;
 110:     else
 111:         namep++;
 112:     strcat(minusnam, namep);
 113:     alarm(0);
 114:     umask(02);
 115:     showmotd();
 116:     strcat(maildir, pwd->pw_name);
 117:     if(access(maildir,4)==0) {
 118:         struct stat statb;
 119:         stat(maildir, &statb);
 120:         if (statb.st_size)
 121:             printf("You have mail.\n");
 122:     }
 123:     signal(SIGQUIT, SIG_DFL);
 124:     signal(SIGINT, SIG_DFL);
 125:     execlp(pwd->pw_shell, minusnam, 0);
 126:     printf("No shell\n");
 127:     exit(0);
 128: }
 129: 
 130: int stopmotd;
 131: catch()
 132: {
 133:     signal(SIGINT, SIG_IGN);
 134:     stopmotd++;
 135: }
 136: 
 137: showmotd()
 138: {
 139:     FILE *mf;
 140:     register c;
 141: 
 142:     signal(SIGINT, catch);
 143:     if((mf = fopen("/etc/motd","r")) != NULL) {
 144:         while((c = getc(mf)) != EOF && stopmotd == 0)
 145:             putchar(c);
 146:         fclose(mf);
 147:     }
 148:     signal(SIGINT, SIG_IGN);
 149: }

Defined functions

Defined variables

Defined macros