1 /* 2 * Copyright (c) 1983 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 char copyright[] = 36 "@(#) Copyright (c) 1983 The Regents of the University of California.\n\ 37 All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 static char sccsid[] = "@(#)rexecd.c 5.12 (Berkeley) 2/25/91"; 42 #endif /* not lint */ 43 44 #include <sys/param.h> 45 #include <sys/ioctl.h> 46 #include <sys/socket.h> 47 #include <sys/time.h> 48 #include <netinet/in.h> 49 #include <signal.h> 50 #include <netdb.h> 51 #include <pwd.h> 52 #include <errno.h> 53 #include <unistd.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <paths.h> 58 59 /*VARARGS1*/ 60 int error(); 61 62 /* 63 * remote execute server: 64 * username\0 65 * password\0 66 * command\0 67 * data 68 */ 69 /*ARGSUSED*/ 70 main(argc, argv) 71 int argc; 72 char **argv; 73 { 74 struct sockaddr_in from; 75 int fromlen; 76 77 fromlen = sizeof (from); 78 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 79 (void)fprintf(stderr, 80 "rexecd: getpeername: %s\n", strerror(errno)); 81 exit(1); 82 } 83 doit(0, &from); 84 } 85 86 char username[20] = "USER="; 87 char homedir[64] = "HOME="; 88 char shell[64] = "SHELL="; 89 char path[sizeof(_PATH_DEFPATH) + sizeof("PATH=")] = "PATH="; 90 char *envinit[] = 91 {homedir, shell, path, username, 0}; 92 char **environ; 93 94 struct sockaddr_in asin = { AF_INET }; 95 96 doit(f, fromp) 97 int f; 98 struct sockaddr_in *fromp; 99 { 100 char cmdbuf[NCARGS+1], *cp, *namep; 101 char user[16], pass[16]; 102 struct passwd *pwd; 103 int s; 104 u_short port; 105 int pv[2], pid, ready, readfrom, cc; 106 char buf[BUFSIZ], sig; 107 int one = 1; 108 109 (void) signal(SIGINT, SIG_DFL); 110 (void) signal(SIGQUIT, SIG_DFL); 111 (void) signal(SIGTERM, SIG_DFL); 112 #ifdef DEBUG 113 { int t = open(_PATH_TTY, 2); 114 if (t >= 0) { 115 ioctl(t, TIOCNOTTY, (char *)0); 116 (void) close(t); 117 } 118 } 119 #endif 120 dup2(f, 0); 121 dup2(f, 1); 122 dup2(f, 2); 123 (void) alarm(60); 124 port = 0; 125 for (;;) { 126 char c; 127 if (read(f, &c, 1) != 1) 128 exit(1); 129 if (c == 0) 130 break; 131 port = port * 10 + c - '0'; 132 } 133 (void) alarm(0); 134 if (port != 0) { 135 s = socket(AF_INET, SOCK_STREAM, 0); 136 if (s < 0) 137 exit(1); 138 if (bind(s, (struct sockaddr *)&asin, sizeof (asin)) < 0) 139 exit(1); 140 (void) alarm(60); 141 fromp->sin_port = htons(port); 142 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) 143 exit(1); 144 (void) alarm(0); 145 } 146 getstr(user, sizeof(user), "username"); 147 getstr(pass, sizeof(pass), "password"); 148 getstr(cmdbuf, sizeof(cmdbuf), "command"); 149 setpwent(); 150 pwd = getpwnam(user); 151 if (pwd == NULL) { 152 error("Login incorrect.\n"); 153 exit(1); 154 } 155 endpwent(); 156 if (*pwd->pw_passwd != '\0') { 157 namep = crypt(pass, pwd->pw_passwd); 158 if (strcmp(namep, pwd->pw_passwd)) { 159 error("Password incorrect.\n"); 160 exit(1); 161 } 162 } 163 if (chdir(pwd->pw_dir) < 0) { 164 error("No remote directory.\n"); 165 exit(1); 166 } 167 (void) write(2, "\0", 1); 168 if (port) { 169 (void) pipe(pv); 170 pid = fork(); 171 if (pid == -1) { 172 error("Try again.\n"); 173 exit(1); 174 } 175 if (pid) { 176 (void) close(0); (void) close(1); (void) close(2); 177 (void) close(f); (void) close(pv[1]); 178 readfrom = (1<<s) | (1<<pv[0]); 179 ioctl(pv[1], FIONBIO, (char *)&one); 180 /* should set s nbio! */ 181 do { 182 ready = readfrom; 183 (void) select(16, (fd_set *)&ready, 184 (fd_set *)NULL, (fd_set *)NULL, 185 (struct timeval *)NULL); 186 if (ready & (1<<s)) { 187 if (read(s, &sig, 1) <= 0) 188 readfrom &= ~(1<<s); 189 else 190 killpg(pid, sig); 191 } 192 if (ready & (1<<pv[0])) { 193 cc = read(pv[0], buf, sizeof (buf)); 194 if (cc <= 0) { 195 shutdown(s, 1+1); 196 readfrom &= ~(1<<pv[0]); 197 } else 198 (void) write(s, buf, cc); 199 } 200 } while (readfrom); 201 exit(0); 202 } 203 setpgrp(0, getpid()); 204 (void) close(s); (void)close(pv[0]); 205 dup2(pv[1], 2); 206 } 207 if (*pwd->pw_shell == '\0') 208 pwd->pw_shell = _PATH_BSHELL; 209 if (f > 2) 210 (void) close(f); 211 (void) setgid((gid_t)pwd->pw_gid); 212 initgroups(pwd->pw_name, pwd->pw_gid); 213 (void) setuid((uid_t)pwd->pw_uid); 214 (void)strcat(path, _PATH_DEFPATH); 215 environ = envinit; 216 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 217 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 218 strncat(username, pwd->pw_name, sizeof(username)-6); 219 cp = rindex(pwd->pw_shell, '/'); 220 if (cp) 221 cp++; 222 else 223 cp = pwd->pw_shell; 224 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 225 perror(pwd->pw_shell); 226 exit(1); 227 } 228 229 /*VARARGS1*/ 230 error(fmt, a1, a2, a3) 231 char *fmt; 232 int a1, a2, a3; 233 { 234 char buf[BUFSIZ]; 235 236 buf[0] = 1; 237 (void) sprintf(buf+1, fmt, a1, a2, a3); 238 (void) write(2, buf, strlen(buf)); 239 } 240 241 getstr(buf, cnt, err) 242 char *buf; 243 int cnt; 244 char *err; 245 { 246 char c; 247 248 do { 249 if (read(0, &c, 1) != 1) 250 exit(1); 251 *buf++ = c; 252 if (--cnt == 0) { 253 error("%s too long\n", err); 254 exit(1); 255 } 256 } while (c != 0); 257 } 258