rexecd.tproj/rexecd.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1983, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  */
  56
  57 #ifndef lint
  58 static char copyright[] =
  59 "@(#) Copyright (c) 1983, 1993\n\
  60         The Regents of the University of California.  All rights reserved.\n";
  61 #endif /* not lint */
  62
  63 #ifndef lint
  64 static char sccsid[] = "@(#)rexecd.c    8.1 (Berkeley) 6/4/93";
  65 #endif /* not lint */
  66
  67 #include <sys/param.h>
  68 #include <sys/ioctl.h>
  69 #include <sys/socket.h>
  70 #include <sys/time.h>
  71
  72 #include <netinet/in.h>
  73
  74 #include <errno.h>
  75 #include <netdb.h>
  76 #include <paths.h>
  77 #include <pwd.h>
  78 #include <signal.h>
  79 #include <stdio.h>
  80 #include <stdlib.h>
  81 #include <string.h>
  82 #include <unistd.h>
  83
  84 /*VARARGS1*/
  85 int error();
  86
  87 /*
  88  * remote execute server:
  89  *      username\0
  90  *      password\0
  91  *      command\0
  92  *      data
  93  */
  94 /*ARGSUSED*/
  95 main(argc, argv)
  96         int argc;
  97         char **argv;
  98 {
  99         struct sockaddr_in from;
 100         int fromlen;
 101
 102         fromlen = sizeof (from);
 103         if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
 104                 (void)fprintf(stderr,
 105                     "rexecd: getpeername: %s\n", strerror(errno));
 106                 exit(1);
 107         }
 108         doit(0, &from);
 109 }
 110
 111 char    username[20] = "USER=";
 112 char    homedir[64] = "HOME=";
 113 char    shell[64] = "SHELL=";
 114 char    path[sizeof(_PATH_DEFPATH) + sizeof("PATH=")] = "PATH=";
 115 char    *envinit[] =
 116             {homedir, shell, path, username, 0};
 117 #ifdef __APPLE__
 118 extern
 119 #endif
 120 char    **environ;
 121
 122 struct  sockaddr_in asin = { AF_INET };
 123
 124 doit(f, fromp)
 125         int f;
 126         struct sockaddr_in *fromp;
 127 {
 128         char cmdbuf[NCARGS+1], *cp, *namep;
 129         char user[16], pass[16];
 130         struct passwd *pwd;
 131         int s;
 132         u_short port;
 133         int pv[2], pid, ready, readfrom, cc;
 134         char buf[BUFSIZ], sig;
 135         int one = 1;
 136
 137         (void) signal(SIGINT, SIG_DFL);
 138         (void) signal(SIGQUIT, SIG_DFL);
 139         (void) signal(SIGTERM, SIG_DFL);
 140 #ifdef DEBUG
 141         { int t = open(_PATH_TTY, 2);
 142           if (t >= 0) {
 143                 ioctl(t, TIOCNOTTY, (char *)0);
 144                 (void) close(t);
 145           }
 146         }
 147 #endif
 148         dup2(f, 0);
 149         dup2(f, 1);
 150         dup2(f, 2);
 151         (void) alarm(60);
 152         port = 0;
 153         for (;;) {
 154                 char c;
 155                 if (read(f, &c, 1) != 1)
 156                         exit(1);
 157                 if (c == 0)
 158                         break;
 159                 port = port * 10 + c - '0';
 160         }
 161         (void) alarm(0);
 162         if (port != 0) {
 163                 s = socket(AF_INET, SOCK_STREAM, 0);
 164                 if (s < 0)
 165                         exit(1);
 166                 if (bind(s, (struct sockaddr *)&asin, sizeof (asin)) < 0)
 167                         exit(1);
 168                 (void) alarm(60);
 169                 fromp->sin_port = htons(port);
 170                 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0)
 171                         exit(1);
 172                 (void) alarm(0);
 173         }
 174         getstr(user, sizeof(user), "username");
 175         getstr(pass, sizeof(pass), "password");
 176         getstr(cmdbuf, sizeof(cmdbuf), "command");
 177         setpwent();
 178         pwd = getpwnam(user);
 179         if (pwd == NULL) {
 180                 error("Login incorrect.\n");
 181                 exit(1);
 182         }
 183         endpwent();
 184         if (*pwd->pw_passwd != '\0') {
 185                 namep = crypt(pass, pwd->pw_passwd);
 186                 if (strcmp(namep, pwd->pw_passwd)) {
 187                         error("Password incorrect.\n");
 188                         exit(1);
 189                 }
 190         }
 191         if (chdir(pwd->pw_dir) < 0) {
 192                 error("No remote directory.\n");
 193                 exit(1);
 194         }
 195         (void) write(2, "\0", 1);
 196         if (port) {
 197                 (void) pipe(pv);
 198                 pid = fork();
 199                 if (pid == -1)  {
 200                         error("Try again.\n");
 201                         exit(1);
 202                 }
 203                 if (pid) {
 204                         (void) close(0); (void) close(1); (void) close(2);
 205                         (void) close(f); (void) close(pv[1]);
 206                         readfrom = (1<<s) | (1<<pv[0]);
 207                         ioctl(pv[1], FIONBIO, (char *)&one);
 208                         /* should set s nbio! */
 209                         do {
 210                                 ready = readfrom;
 211                                 (void) select(16, (fd_set *)&ready,
 212                                     (fd_set *)NULL, (fd_set *)NULL,
 213                                     (struct timeval *)NULL);
 214                                 if (ready & (1<<s)) {
 215                                         if (read(s, &sig, 1) <= 0)
 216                                                 readfrom &= ~(1<<s);
 217                                         else
 218                                                 killpg(pid, sig);
 219                                 }
 220                                 if (ready & (1<<pv[0])) {
 221                                         cc = read(pv[0], buf, sizeof (buf));
 222                                         if (cc <= 0) {
 223                                                 shutdown(s, 1+1);
 224                                                 readfrom &= ~(1<<pv[0]);
 225                                         } else
 226                                                 (void) write(s, buf, cc);
 227                                 }
 228                         } while (readfrom);
 229                         exit(0);
 230                 }
 231                 setpgrp(0, getpid());
 232                 (void) close(s); (void)close(pv[0]);
 233                 dup2(pv[1], 2);
 234         }
 235         if (*pwd->pw_shell == '\0')
 236                 pwd->pw_shell = _PATH_BSHELL;
 237         if (f > 2)
 238                 (void) close(f);
 239         (void) setgid((gid_t)pwd->pw_gid);
 240         initgroups(pwd->pw_name, pwd->pw_gid);
 241         (void) setuid((uid_t)pwd->pw_uid);
 242         (void)strcat(path, _PATH_DEFPATH);
 243         environ = envinit;
 244         strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
 245         strncat(shell, pwd->pw_shell, sizeof(shell)-7);
 246         strncat(username, pwd->pw_name, sizeof(username)-6);
 247         cp = strrchr(pwd->pw_shell, '/');
 248         if (cp)
 249                 cp++;
 250         else
 251                 cp = pwd->pw_shell;
 252         execl(pwd->pw_shell, cp, "-c", cmdbuf, 0);
 253         perror(pwd->pw_shell);
 254         exit(1);
 255 }
 256
 257 /*VARARGS1*/
 258 error(fmt, a1, a2, a3)
 259         char *fmt;
 260         int a1, a2, a3;
 261 {
 262         char buf[BUFSIZ];
 263
 264         buf[0] = 1;
 265         (void) sprintf(buf+1, fmt, a1, a2, a3);
 266         (void) write(2, buf, strlen(buf));
 267 }
 268
 269 getstr(buf, cnt, err)
 270         char *buf;
 271         int cnt;
 272         char *err;
 273 {
 274         char c;
 275
 276         do {
 277                 if (read(0, &c, 1) != 1)
 278                         exit(1);
 279                 *buf++ = c;
 280                 if (--cnt == 0) {
 281                         error("%s too long\n", err);
 282                         exit(1);
 283                 }
 284         } while (c != 0);
 285 }