4.3BSD - /usr/src/etc/rexecd.c

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: char copyright[] =
   9: "@(#) Copyright (c) 1983 Regents of the University of California.\n\
  10:  All rights reserved.\n";
  11: #endif not lint
  12: 
  13: #ifndef lint
  14: static char sccsid[] = "@(#)rexecd.c	5.4 (Berkeley) 5/9/86";
  15: #endif not lint
  16: 
  17: #include <sys/ioctl.h>
  18: #include <sys/param.h>
  19: #include <sys/socket.h>
  20: #include <sys/time.h>
  21: 
  22: #include <netinet/in.h>
  23: 
  24: #include <stdio.h>
  25: #include <errno.h>
  26: #include <pwd.h>
  27: #include <signal.h>
  28: #include <netdb.h>
  29: 
  30: extern  errno;
  31: struct  passwd *getpwnam();
  32: char    *crypt(), *rindex(), *strncat(), *sprintf();
  33: /*VARARGS1*/
  34: int error();
  35: 
  36: /*
  37:  * remote execute server:
  38:  *	username\0
  39:  *	password\0
  40:  *	command\0
  41:  *	data
  42:  */
  43: /*ARGSUSED*/
  44: main(argc, argv)
  45:     int argc;
  46:     char **argv;
  47: {
  48:     struct sockaddr_in from;
  49:     int fromlen;
  50: 
  51:     fromlen = sizeof (from);
  52:     if (getpeername(0, &from, &fromlen) < 0) {
  53:         fprintf(stderr, "%s: ", argv[0]);
  54:         perror("getpeername");
  55:         exit(1);
  56:     }
  57:     doit(0, &from);
  58: }
  59: 
  60: char    username[20] = "USER=";
  61: char    homedir[64] = "HOME=";
  62: char    shell[64] = "SHELL=";
  63: char    *envinit[] =
  64:         {homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", username, 0};
  65: char    **environ;
  66: 
  67: struct  sockaddr_in asin = { AF_INET };
  68: 
  69: doit(f, fromp)
  70:     int f;
  71:     struct sockaddr_in *fromp;
  72: {
  73:     char cmdbuf[NCARGS+1], *cp, *namep;
  74:     char user[16], pass[16];
  75:     struct passwd *pwd;
  76:     int s;
  77:     short port;
  78:     int pv[2], pid, ready, readfrom, cc;
  79:     char buf[BUFSIZ], sig;
  80:     int one = 1;
  81: 
  82:     (void) signal(SIGINT, SIG_DFL);
  83:     (void) signal(SIGQUIT, SIG_DFL);
  84:     (void) signal(SIGTERM, SIG_DFL);
  85: #ifdef DEBUG
  86:     { int t = open("/dev/tty", 2);
  87:       if (t >= 0) {
  88:         ioctl(t, TIOCNOTTY, (char *)0);
  89:         (void) close(t);
  90:       }
  91:     }
  92: #endif
  93:     dup2(f, 0);
  94:     dup2(f, 1);
  95:     dup2(f, 2);
  96:     (void) alarm(60);
  97:     port = 0;
  98:     for (;;) {
  99:         char c;
 100:         if (read(f, &c, 1) != 1)
 101:             exit(1);
 102:         if (c == 0)
 103:             break;
 104:         port = port * 10 + c - '0';
 105:     }
 106:     (void) alarm(0);
 107:     if (port != 0) {
 108:         s = socket(AF_INET, SOCK_STREAM, 0);
 109:         if (s < 0)
 110:             exit(1);
 111:         if (bind(s, &asin, sizeof (asin)) < 0)
 112:             exit(1);
 113:         (void) alarm(60);
 114:         fromp->sin_port = htons((u_short)port);
 115:         if (connect(s, fromp, sizeof (*fromp)) < 0)
 116:             exit(1);
 117:         (void) alarm(0);
 118:     }
 119:     getstr(user, sizeof(user), "username");
 120:     getstr(pass, sizeof(pass), "password");
 121:     getstr(cmdbuf, sizeof(cmdbuf), "command");
 122:     setpwent();
 123:     pwd = getpwnam(user);
 124:     if (pwd == NULL) {
 125:         error("Login incorrect.\n");
 126:         exit(1);
 127:     }
 128:     endpwent();
 129:     if (*pwd->pw_passwd != '\0') {
 130:         namep = crypt(pass, pwd->pw_passwd);
 131:         if (strcmp(namep, pwd->pw_passwd)) {
 132:             error("Password incorrect.\n");
 133:             exit(1);
 134:         }
 135:     }
 136:     if (chdir(pwd->pw_dir) < 0) {
 137:         error("No remote directory.\n");
 138:         exit(1);
 139:     }
 140:     (void) write(2, "\0", 1);
 141:     if (port) {
 142:         (void) pipe(pv);
 143:         pid = fork();
 144:         if (pid == -1)  {
 145:             error("Try again.\n");
 146:             exit(1);
 147:         }
 148:         if (pid) {
 149:             (void) close(0); (void) close(1); (void) close(2);
 150:             (void) close(f); (void) close(pv[1]);
 151:             readfrom = (1<<s) | (1<<pv[0]);
 152:             ioctl(pv[1], FIONBIO, (char *)&one);
 153:             /* should set s nbio! */
 154:             do {
 155:                 ready = readfrom;
 156:                 (void) select(16, &ready, (fd_set *)0,
 157:                     (fd_set *)0, (struct timeval *)0);
 158:                 if (ready & (1<<s)) {
 159:                     if (read(s, &sig, 1) <= 0)
 160:                         readfrom &= ~(1<<s);
 161:                     else
 162:                         killpg(pid, sig);
 163:                 }
 164:                 if (ready & (1<<pv[0])) {
 165:                     cc = read(pv[0], buf, sizeof (buf));
 166:                     if (cc <= 0) {
 167:                         shutdown(s, 1+1);
 168:                         readfrom &= ~(1<<pv[0]);
 169:                     } else
 170:                         (void) write(s, buf, cc);
 171:                 }
 172:             } while (readfrom);
 173:             exit(0);
 174:         }
 175:         setpgrp(0, getpid());
 176:         (void) close(s); (void)close(pv[0]);
 177:         dup2(pv[1], 2);
 178:     }
 179:     if (*pwd->pw_shell == '\0')
 180:         pwd->pw_shell = "/bin/sh";
 181:     if (f > 2)
 182:         (void) close(f);
 183:     (void) setgid((gid_t)pwd->pw_gid);
 184:     initgroups(pwd->pw_name, pwd->pw_gid);
 185:     (void) setuid((uid_t)pwd->pw_uid);
 186:     environ = envinit;
 187:     strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
 188:     strncat(shell, pwd->pw_shell, sizeof(shell)-7);
 189:     strncat(username, pwd->pw_name, sizeof(username)-6);
 190:     cp = rindex(pwd->pw_shell, '/');
 191:     if (cp)
 192:         cp++;
 193:     else
 194:         cp = pwd->pw_shell;
 195:     execl(pwd->pw_shell, cp, "-c", cmdbuf, 0);
 196:     perror(pwd->pw_shell);
 197:     exit(1);
 198: }
 199: 
 200: /*VARARGS1*/
 201: error(fmt, a1, a2, a3)
 202:     char *fmt;
 203:     int a1, a2, a3;
 204: {
 205:     char buf[BUFSIZ];
 206: 
 207:     buf[0] = 1;
 208:     (void) sprintf(buf+1, fmt, a1, a2, a3);
 209:     (void) write(2, buf, strlen(buf));
 210: }
 211: 
 212: getstr(buf, cnt, err)
 213:     char *buf;
 214:     int cnt;
 215:     char *err;
 216: {
 217:     char c;
 218: 
 219:     do {
 220:         if (read(0, &c, 1) != 1)
 221:             exit(1);
 222:         *buf++ = c;
 223:         if (--cnt == 0) {
 224:             error("%s too long\n", err);
 225:             exit(1);
 226:         }
 227:     } while (c != 0);
 228: }

Defined functions

Defined variables