rexecd.c revision 1.2
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[] = "from: @(#)rexecd.c 5.12 (Berkeley) 2/25/91";*/ 42 static char rcsid[] = "$Id: rexecd.c,v 1.2 1993/08/01 18:30:01 mycroft Exp $"; 43 #endif /* not lint */ 44 45 #include <sys/param.h> 46 #include <sys/ioctl.h> 47 #include <sys/socket.h> 48 #include <sys/time.h> 49 #include <netinet/in.h> 50 #include <signal.h> 51 #include <netdb.h> 52 #include <pwd.h> 53 #include <errno.h> 54 #include <unistd.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <paths.h> 59 60 /*VARARGS1*/ 61 int error(); 62 63 /* 64 * remote execute server: 65 * username\0 66 * password\0 67 * command\0 68 * data 69 */ 70 /*ARGSUSED*/ 71 main(argc, argv) 72 int argc; 73 char **argv; 74 { 75 struct sockaddr_in from; 76 int fromlen; 77 78 fromlen = sizeof (from); 79 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { 80 (void)fprintf(stderr, 81 "rexecd: getpeername: %s\n", strerror(errno)); 82 exit(1); 83 } 84 doit(0, &from); 85 } 86 87 char username[20] = "USER="; 88 char homedir[64] = "HOME="; 89 char shell[64] = "SHELL="; 90 char path[sizeof(_PATH_DEFPATH) + sizeof("PATH=")] = "PATH="; 91 char *envinit[] = 92 {homedir, shell, path, username, 0}; 93 char **environ; 94 95 struct sockaddr_in asin = { AF_INET }; 96 97 doit(f, fromp) 98 int f; 99 struct sockaddr_in *fromp; 100 { 101 char cmdbuf[NCARGS+1], *cp, *namep; 102 char user[16], pass[16]; 103 struct passwd *pwd; 104 int s; 105 u_short port; 106 int pv[2], pid, ready, readfrom, cc; 107 char buf[BUFSIZ], sig; 108 int one = 1; 109 110 (void) signal(SIGINT, SIG_DFL); 111 (void) signal(SIGQUIT, SIG_DFL); 112 (void) signal(SIGTERM, SIG_DFL); 113 #ifdef DEBUG 114 { int t = open(_PATH_TTY, 2); 115 if (t >= 0) { 116 ioctl(t, TIOCNOTTY, (char *)0); 117 (void) close(t); 118 } 119 } 120 #endif 121 dup2(f, 0); 122 dup2(f, 1); 123 dup2(f, 2); 124 (void) alarm(60); 125 port = 0; 126 for (;;) { 127 char c; 128 if (read(f, &c, 1) != 1) 129 exit(1); 130 if (c == 0) 131 break; 132 port = port * 10 + c - '0'; 133 } 134 (void) alarm(0); 135 if (port != 0) { 136 s = socket(AF_INET, SOCK_STREAM, 0); 137 if (s < 0) 138 exit(1); 139 if (bind(s, (struct sockaddr *)&asin, sizeof (asin)) < 0) 140 exit(1); 141 (void) alarm(60); 142 fromp->sin_port = htons(port); 143 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) 144 exit(1); 145 (void) alarm(0); 146 } 147 getstr(user, sizeof(user), "username"); 148 getstr(pass, sizeof(pass), "password"); 149 getstr(cmdbuf, sizeof(cmdbuf), "command"); 150 setpwent(); 151 pwd = getpwnam(user); 152 if (pwd == NULL) { 153 error("Login incorrect.\n"); 154 exit(1); 155 } 156 endpwent(); 157 if (*pwd->pw_passwd != '\0') { 158 namep = crypt(pass, pwd->pw_passwd); 159 if (strcmp(namep, pwd->pw_passwd)) { 160 error("Password incorrect.\n"); 161 exit(1); 162 } 163 } 164 if (chdir(pwd->pw_dir) < 0) { 165 error("No remote directory.\n"); 166 exit(1); 167 } 168 (void) write(2, "\0", 1); 169 if (port) { 170 (void) pipe(pv); 171 pid = fork(); 172 if (pid == -1) { 173 error("Try again.\n"); 174 exit(1); 175 } 176 if (pid) { 177 (void) close(0); (void) close(1); (void) close(2); 178 (void) close(f); (void) close(pv[1]); 179 readfrom = (1<<s) | (1<<pv[0]); 180 ioctl(pv[1], FIONBIO, (char *)&one); 181 /* should set s nbio! */ 182 do { 183 ready = readfrom; 184 (void) select(16, (fd_set *)&ready, 185 (fd_set *)NULL, (fd_set *)NULL, 186 (struct timeval *)NULL); 187 if (ready & (1<<s)) { 188 if (read(s, &sig, 1) <= 0) 189 readfrom &= ~(1<<s); 190 else 191 killpg(pid, sig); 192 } 193 if (ready & (1<<pv[0])) { 194 cc = read(pv[0], buf, sizeof (buf)); 195 if (cc <= 0) { 196 shutdown(s, 1+1); 197 readfrom &= ~(1<<pv[0]); 198 } else 199 (void) write(s, buf, cc); 200 } 201 } while (readfrom); 202 exit(0); 203 } 204 setpgrp(0, getpid()); 205 (void) close(s); (void)close(pv[0]); 206 dup2(pv[1], 2); 207 } 208 if (*pwd->pw_shell == '\0') 209 pwd->pw_shell = _PATH_BSHELL; 210 if (f > 2) 211 (void) close(f); 212 (void) setgid((gid_t)pwd->pw_gid); 213 initgroups(pwd->pw_name, pwd->pw_gid); 214 (void) setuid((uid_t)pwd->pw_uid); 215 (void)strcat(path, _PATH_DEFPATH); 216 environ = envinit; 217 strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); 218 strncat(shell, pwd->pw_shell, sizeof(shell)-7); 219 strncat(username, pwd->pw_name, sizeof(username)-6); 220 cp = rindex(pwd->pw_shell, '/'); 221 if (cp) 222 cp++; 223 else 224 cp = pwd->pw_shell; 225 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 226 perror(pwd->pw_shell); 227 exit(1); 228 } 229 230 /*VARARGS1*/ 231 error(fmt, a1, a2, a3) 232 char *fmt; 233 int a1, a2, a3; 234 { 235 char buf[BUFSIZ]; 236 237 buf[0] = 1; 238 (void) sprintf(buf+1, fmt, a1, a2, a3); 239 (void) write(2, buf, strlen(buf)); 240 } 241 242 getstr(buf, cnt, err) 243 char *buf; 244 int cnt; 245 char *err; 246 { 247 char c; 248 249 do { 250 if (read(0, &c, 1) != 1) 251 exit(1); 252 *buf++ = c; 253 if (--cnt == 0) { 254 error("%s too long\n", err); 255 exit(1); 256 } 257 } while (c != 0); 258 } 259
Indexes created Fri Oct 17 03:10:13 GMT 2025