rexecd.c revision 1.6.2.1
1 /* $NetBSD: rexecd.c,v 1.6.2.1 2000/10/10 21:48:10 he Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #if 0 41 static char sccsid[] = "from: @(#)rexecd.c 8.1 (Berkeley) 6/4/93"; 42 #else 43 __RCSID("$NetBSD: rexecd.c,v 1.6.2.1 2000/10/10 21:48:10 he Exp $"); 44 #endif 45 #endif /* not lint */ 46 47 #include <sys/param.h> 48 #include <sys/ioctl.h> 49 #include <sys/poll.h> 50 #include <sys/socket.h> 51 #include <sys/syslog.h> 52 #include <sys/time.h> 53 54 #include <netinet/in.h> 55 56 #include <err.h> 57 #include <errno.h> 58 #include <netdb.h> 59 #include <paths.h> 60 #include <pwd.h> 61 #include <signal.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <unistd.h> 66 67 void error __P((const char *, ...)) 68 __attribute__((__format__(__printf__, 1, 2))); 69 int main __P((int, char **)); 70 void doit __P((int, struct sockaddr_in *)); 71 void getstr __P((char *, int, char *)); 72 73 char username[32 + 1] = "USER="; 74 char homedir[PATH_MAX + 1] = "HOME="; 75 char shell[PATH_MAX + 1] = "SHELL="; 76 char path[sizeof(_PATH_DEFPATH) + sizeof("PATH=")] = "PATH="; 77 char *envinit[] = { homedir, shell, path, username, 0 }; 78 char **environ; 79 int log; 80 struct sockaddr_in asin = { AF_INET }; 81 82 /* 83 * remote execute server: 84 * username\0 85 * password\0 86 * command\0 87 * data 88 */ 89 int 90 main(argc, argv) 91 int argc; 92 char **argv; 93 { 94 struct sockaddr_in from; 95 int fromlen, ch; 96 97 while ((ch = getopt(argc, argv, "l")) != -1) 98 switch (ch) { 99 case 'l': 100 log = 1; 101 openlog("rexecd", LOG_PID, LOG_DAEMON); 102 break; 103 default: 104 exit(1); 105 } 106 107 fromlen = sizeof (from); 108 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) 109 err(1, "getpeername"); 110 111 doit(0, &from); 112 exit(0); 113 } 114 115 void 116 doit(f, fromp) 117 int f; 118 struct sockaddr_in *fromp; 119 { 120 struct pollfd fds[2]; 121 char cmdbuf[NCARGS+1], *namep; 122 const char *cp; 123 char user[16], pass[16]; 124 char buf[BUFSIZ], sig; 125 struct passwd *pwd; 126 int s = -1; /* XXX gcc */ 127 int pv[2], pid, cc; 128 int one = 1; 129 in_port_t port; 130 131 (void)signal(SIGINT, SIG_DFL); 132 (void)signal(SIGQUIT, SIG_DFL); 133 (void)signal(SIGTERM, SIG_DFL); 134 dup2(f, 0); 135 dup2(f, 1); 136 dup2(f, 2); 137 (void)alarm(60); 138 port = 0; 139 for (;;) { 140 char c; 141 if (read(f, &c, 1) != 1) { 142 if (log) 143 syslog(LOG_ERR, 144 "initial read failed"); 145 exit(1); 146 } 147 if (c == 0) 148 break; 149 port = port * 10 + c - '0'; 150 } 151 (void)alarm(0); 152 if (port != 0) { 153 s = socket(AF_INET, SOCK_STREAM, 0); 154 if (s < 0) { 155 if (log) 156 syslog(LOG_ERR, "socket: %m"); 157 exit(1); 158 } 159 if (bind(s, (struct sockaddr *)&asin, sizeof (asin)) < 0) { 160 if (log) 161 syslog(LOG_ERR, "bind: %m"); 162 exit(1); 163 } 164 (void)alarm(60); 165 fromp->sin_port = htons(port); 166 if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) { 167 if (log) 168 syslog(LOG_ERR, "connect: %m"); 169 exit(1); 170 } 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 if (log) 181 syslog(LOG_ERR, "no such user %s", user); 182 exit(1); 183 } 184 endpwent(); 185 if (*pwd->pw_passwd != '\0') { 186 namep = crypt(pass, pwd->pw_passwd); 187 if (strcmp(namep, pwd->pw_passwd)) { 188 error("Password incorrect.\n"); /* XXX: wrong! */ 189 if (log) 190 syslog(LOG_ERR, "incorrect password for %s", 191 user); 192 exit(1); 193 } 194 } else 195 (void)crypt("dummy password", "PA"); /* must always crypt */ 196 if (chdir(pwd->pw_dir) < 0) { 197 error("No remote directory.\n"); 198 if (log) 199 syslog(LOG_ERR, "%s does not exist for %s", pwd->pw_dir, 200 user); 201 exit(1); 202 } 203 (void)write(2, "\0", 1); 204 if (port) { 205 if (pipe(pv) < 0 || (pid = fork()) == -1) { 206 error("Try again.\n"); 207 if (log) 208 syslog(LOG_ERR,"pipe or fork failed for %s: %m", 209 user); 210 exit(1); 211 } 212 if (pid) { 213 (void)close(0); 214 (void)close(1); 215 (void)close(2); 216 (void)close(f); 217 (void)close(pv[1]); 218 fds[0].fd = s; 219 fds[1].fd = pv[0]; 220 fds[0].events = fds[1].events = POLLIN; 221 if (ioctl(pv[1], FIONBIO, (char *)&one) < 0) 222 _exit(-1); 223 /* should set s nbio! */ 224 do { 225 if (poll(fds, 2, 0) < 0) { 226 close(s); 227 close(pv[0]); 228 _exit(-1); 229 } 230 if (fds[0].revents & POLLIN) { 231 if (read(s, &sig, 1) <= 0) 232 fds[0].events = 0; 233 else 234 killpg(pid, sig); 235 } 236 if (fds[1].revents & POLLIN) { 237 cc = read(pv[0], buf, sizeof (buf)); 238 if (cc <= 0) { 239 shutdown(s, 1+1); 240 fds[1].events = 0; 241 } else 242 (void)write(s, buf, cc); 243 } 244 } while ((fds[0].events | fds[1].events) & POLLIN); 245 _exit(0); 246 } 247 (void)setpgrp(0, getpid()); 248 (void)close(s); 249 (void)close(pv[0]); 250 if (dup2(pv[1], 2) < 0) { 251 error("Try again.\n"); 252 if (log) 253 syslog(LOG_ERR, "dup2 failed for %s", user); 254 exit(1); 255 } 256 } 257 if (*pwd->pw_shell == '\0') 258 pwd->pw_shell = _PATH_BSHELL; 259 if (f > 2) 260 (void)close(f); 261 if (setlogin(pwd->pw_name) < 0 || 262 initgroups(pwd->pw_name, pwd->pw_gid) < 0 || 263 setgid((gid_t)pwd->pw_gid) < 0 || 264 setuid((uid_t)pwd->pw_uid) < 0) { 265 error("Try again.\n"); 266 if (log) 267 syslog(LOG_ERR, "could not set permissions for %s: %m", 268 user); 269 exit(1); 270 } 271 (void)strcat(path, _PATH_DEFPATH); 272 environ = envinit; 273 strncat(homedir, pwd->pw_dir, sizeof(homedir) - 6); 274 strncat(shell, pwd->pw_shell, sizeof(shell) - 7); 275 strncat(username, pwd->pw_name, sizeof(username) - 6); 276 cp = strrchr(pwd->pw_shell, '/'); 277 if (cp) 278 cp++; 279 else 280 cp = pwd->pw_shell; 281 if (log) 282 syslog(LOG_INFO, "running command for %s: %s", user, cmdbuf); 283 execl(pwd->pw_shell, cp, "-c", cmdbuf, 0); 284 perror(pwd->pw_shell); 285 if (log) 286 syslog(LOG_ERR, "execl failed for %s: %m", user); 287 exit(1); 288 } 289 290 #ifdef __STDC__ 291 #include <stdarg.h> 292 #else 293 #include <varargs.h> 294 #endif 295 296 void 297 #ifdef __STDC__ 298 error(const char *fmt, ...) 299 #else 300 error(fmt, va_alist) 301 char *fmt; 302 va_dcl 303 #endif 304 { 305 char buf[BUFSIZ]; 306 va_list ap; 307 308 #ifdef __STDC__ 309 va_start(ap, fmt); 310 #else 311 va_start(ap); 312 #endif 313 314 buf[0] = 1; 315 (void)vsnprintf(buf+1, sizeof(buf) - 1, fmt, ap); 316 (void)write(2, buf, strlen(buf)); 317 } 318 319 void 320 getstr(buf, cnt, err) 321 char *buf; 322 int cnt; 323 char *err; 324 { 325 char c; 326 327 do { 328 if (read(0, &c, 1) != 1) 329 exit(1); 330 *buf++ = c; 331 if (--cnt == 0) { 332 error("%s too long\n", err); 333 exit(1); 334 } 335 } while (c != 0); 336 } 337
Indexes created Wed Oct 15 16:09:53 GMT 2025