rexecd.tproj/rexecd.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1983, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  */
  55
  56 #ifndef lint
  57 static char copyright[] =
  58 "@(#) Copyright (c) 1983, 1993\n\
  59         The Regents of the University of California.  All rights reserved.\n";
  60 #endif /* not lint */
  61
  62 #ifndef lint
  63 static char sccsid[] = "@(#)rexecd.c    8.1 (Berkeley) 6/4/93";
  64 #endif /* not lint */
  65
  66 #include <sys/param.h>
  67 #include <sys/ioctl.h>
  68 #include <sys/socket.h>
  69 #include <sys/time.h>
  70
  71 #include <netinet/in.h>
  72
  73 #include <errno.h>
  74 #include <netdb.h>
  75 #include <paths.h>
  76 #include <pwd.h>
  77 #include <signal.h>
  78 #include <stdio.h>
  79 #include <stdlib.h>
  80 #include <string.h>
  81 #include <unistd.h>
  82
  83 /*VARARGS1*/
  84 int error();
  85
  86 /*
  87  * remote execute server:
  88  *      username\0
  89  *      password\0
  90  *      command\0
  91  *      data
  92  */
  93 /*ARGSUSED*/
  94 main(argc, argv)
  95         int argc;
  96         char **argv;
  97 {
  98         struct sockaddr_in from;
  99         int fromlen;
 100
 101         fromlen = sizeof (from);
 102         if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
 103                 (void)fprintf(stderr,
 104                     "rexecd: getpeername: %s\n", strerror(errno));
 105                 exit(1);
 106         }
 107         doit(0, &from);
 108 }
 109
 110 char    username[20] = "USER=";
 111 char    homedir[64] = "HOME=";
 112 char    shell[64] = "SHELL=";
 113 char    path[sizeof(_PATH_DEFPATH) + sizeof("PATH=")] = "PATH=";
 114 char    *envinit[] =
 115             {homedir, shell, path, username, 0};
 116 #ifdef __APPLE__
 117 extern
 118 #endif
 119 char    **environ;
 120
 121 struct  sockaddr_in asin = { AF_INET };
 122
 123 doit(f, fromp)
 124         int f;
 125         struct sockaddr_in *fromp;
 126 {
 127         char cmdbuf[NCARGS+1], *cp, *namep;
 128         char user[16], pass[16];
 129         struct passwd *pwd;
 130         int s;
 131         u_short port;
 132         int pv[2], pid, ready, readfrom, cc;
 133         char buf[BUFSIZ], sig;
 134         int one = 1;
 135
 136         (void) signal(SIGINT, SIG_DFL);
 137         (void) signal(SIGQUIT, SIG_DFL);
 138         (void) signal(SIGTERM, SIG_DFL);
 139 #ifdef DEBUG
 140         { int t = open(_PATH_TTY, 2);
 141           if (t >= 0) {
 142                 ioctl(t, TIOCNOTTY, (char *)0);
 143                 (void) close(t);
 144           }
 145         }
 146 #endif
 147         dup2(f, 0);
 148         dup2(f, 1);
 149         dup2(f, 2);
 150         (void) alarm(60);
 151         port = 0;
 152         for (;;) {
 153                 char c;
 154                 if (read(f, &c, 1) != 1)
 155                         exit(1);
 156                 if (c == 0)
 157                         break;
 158                 port = port * 10 + c - '0';
 159         }
 160         (void) alarm(0);
 161         if (port != 0) {
 162                 s = socket(AF_INET, SOCK_STREAM, 0);
 163                 if (s < 0)
 164                         exit(1);
 165                 if (bind(s, (struct sockaddr *)&asin, sizeof (asin)) < 0)
 166                         exit(1);
 167                 (void) alarm(60);
 168                 fromp->sin_port = htons(port);
 169                 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0)
 170                         exit(1);
 171                 (void) alarm(0);
 172         }
 173         getstr(user, sizeof(user), "username");
 174         getstr(pass, sizeof(pass), "password");
 175         getstr(cmdbuf, sizeof(cmdbuf), "command");
 176         setpwent();
 177         pwd = getpwnam(user);
 178         if (pwd == NULL) {
 179                 error("Login incorrect.\n");
 180                 exit(1);
 181         }
 182         endpwent();
 183         if (*pwd->pw_passwd != '\0') {
 184                 namep = crypt(pass, pwd->pw_passwd);
 185                 if (strcmp(namep, pwd->pw_passwd)) {
 186                         error("Password incorrect.\n");
 187                         exit(1);
 188                 }
 189         }
 190         if (chdir(pwd->pw_dir) < 0) {
 191                 error("No remote directory.\n");
 192                 exit(1);
 193         }
 194         (void) write(2, "\0", 1);
 195         if (port) {
 196                 (void) pipe(pv);
 197                 pid = fork();
 198                 if (pid == -1)  {
 199                         error("Try again.\n");
 200                         exit(1);
 201                 }
 202                 if (pid) {
 203                         (void) close(0); (void) close(1); (void) close(2);
 204                         (void) close(f); (void) close(pv[1]);
 205                         readfrom = (1<<s) | (1<<pv[0]);
 206                         ioctl(pv[1], FIONBIO, (char *)&one);
 207                         /* should set s nbio! */
 208                         do {
 209                                 ready = readfrom;
 210                                 (void) select(16, (fd_set *)&ready,
 211                                     (fd_set *)NULL, (fd_set *)NULL,
 212                                     (struct timeval *)NULL);
 213                                 if (ready & (1<<s)) {
 214                                         if (read(s, &sig, 1) <= 0)
 215                                                 readfrom &= ~(1<<s);
 216                                         else
 217                                                 killpg(pid, sig);
 218                                 }
 219                                 if (ready & (1<<pv[0])) {
 220                                         cc = read(pv[0], buf, sizeof (buf));
 221                                         if (cc <= 0) {
 222                                                 shutdown(s, 1+1);
 223                                                 readfrom &= ~(1<<pv[0]);
 224                                         } else
 225                                                 (void) write(s, buf, cc);
 226                                 }
 227                         } while (readfrom);
 228                         exit(0);
 229                 }
 230                 setpgrp(0, getpid());
 231                 (void) close(s); (void)close(pv[0]);
 232                 dup2(pv[1], 2);
 233         }
 234         if (*pwd->pw_shell == '\0')
 235                 pwd->pw_shell = _PATH_BSHELL;
 236         if (f > 2)
 237                 (void) close(f);
 238         (void) setgid((gid_t)pwd->pw_gid);
 239         initgroups(pwd->pw_name, pwd->pw_gid);
 240         (void) setuid((uid_t)pwd->pw_uid);
 241         (void)strcat(path, _PATH_DEFPATH);
 242         environ = envinit;
 243         strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
 244         strncat(shell, pwd->pw_shell, sizeof(shell)-7);
 245         strncat(username, pwd->pw_name, sizeof(username)-6);
 246         cp = strrchr(pwd->pw_shell, '/');
 247         if (cp)
 248                 cp++;
 249         else
 250                 cp = pwd->pw_shell;
 251         execl(pwd->pw_shell, cp, "-c", cmdbuf, 0);
 252         perror(pwd->pw_shell);
 253         exit(1);
 254 }
 255
 256 /*VARARGS1*/
 257 error(fmt, a1, a2, a3)
 258         char *fmt;
 259         int a1, a2, a3;
 260 {
 261         char buf[BUFSIZ];
 262
 263         buf[0] = 1;
 264         (void) sprintf(buf+1, fmt, a1, a2, a3);
 265         (void) write(2, buf, strlen(buf));
 266 }
 267
 268 getstr(buf, cnt, err)
 269         char *buf;
 270         int cnt;
 271         char *err;
 272 {
 273         char c;
 274
 275         do {
 276                 if (read(0, &c, 1) != 1)
 277                         exit(1);
 278                 *buf++ = c;
 279                 if (--cnt == 0) {
 280                         error("%s too long\n", err);
 281                         exit(1);
 282                 }
 283         } while (c != 0);
 284 }