1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 */ 40 41 #include "lp.cdefs.h" /* A cross-platform version of <sys/cdefs.h> */ 42 #include <sys/param.h> 43 #include <sys/socket.h> 44 #include <sys/stat.h> 45 #include <sys/time.h> 46 #include <sys/uio.h> 47 48 #include <netinet/in.h> 49 #include <arpa/inet.h> 50 #include <netdb.h> 51 52 #include <dirent.h> /* required for lp.h, not used here */ 53 #include <err.h> 54 #include <errno.h> 55 #include <stdarg.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 #include "lp.h" 62 #include "lp.local.h" 63 #include "pathnames.h" 64 65 /* 66 * 'local_host' is always the hostname of the machine which is running 67 * lpr (lpd, whatever), while 'from_host' either points at 'local_host' 68 * or points at a different buffer when receiving a job from a remote 69 * machine (and that buffer has the hostname of that remote machine). 70 */ 71 char local_host[MAXHOSTNAMELEN]; /* host running lpd/lpr */ 72 const char *from_host = local_host; /* client's machine name */ 73 const char *from_ip = ""; /* client machine's IP address */ 74 75 #ifdef INET6 76 u_char family = PF_UNSPEC; 77 #else 78 u_char family = PF_INET; 79 #endif 80 81 /* 82 * Create a TCP connection to host "rhost" at port "rport". 83 * If rport == 0, then use the printer service port. 84 * Most of this code comes from rcmd.c. 85 */ 86 int 87 getport(const struct printer *pp, const char *rhost, int rport) 88 { 89 struct addrinfo hints, *res, *ai; 90 int s, timo = 1, lport = IPPORT_RESERVED - 1; 91 int error, refused = 0; 92 93 /* 94 * Get the host address and port number to connect to. 95 */ 96 if (rhost == NULL) 97 fatal(pp, "no remote host to connect to"); 98 memset(&hints, 0, sizeof(hints)); 99 hints.ai_family = family; 100 hints.ai_socktype = SOCK_STREAM; 101 hints.ai_protocol = 0; 102 error = getaddrinfo(rhost, (rport == 0 ? "printer" : NULL), 103 &hints, &res); 104 if (error) 105 fatal(pp, "%s\n", gai_strerror(error)); 106 if (rport != 0) 107 ((struct sockaddr_in *) res->ai_addr)->sin_port = htons(rport); 108 109 /* 110 * Try connecting to the server. 111 */ 112 ai = res; 113 retry: 114 PRIV_START 115 s = rresvport_af(&lport, ai->ai_family); 116 PRIV_END 117 if (s < 0) { 118 if (errno != EAGAIN) { 119 if (ai->ai_next) { 120 ai = ai->ai_next; 121 goto retry; 122 } 123 if (refused && timo <= 16) { 124 sleep(timo); 125 timo *= 2; 126 refused = 0; 127 ai = res; 128 goto retry; 129 } 130 } 131 freeaddrinfo(res); 132 return(-1); 133 } 134 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) { 135 error = errno; 136 (void) close(s); 137 errno = error; 138 /* 139 * This used to decrement lport, but the current semantics 140 * of rresvport do not provide such a function (in fact, 141 * rresvport should guarantee that the chosen port will 142 * never result in an EADDRINUSE). 143 */ 144 if (errno == EADDRINUSE) { 145 goto retry; 146 } 147 148 if (errno == ECONNREFUSED) 149 refused++; 150 151 if (ai->ai_next != NULL) { 152 ai = ai->ai_next; 153 goto retry; 154 } 155 if (refused && timo <= 16) { 156 sleep(timo); 157 timo *= 2; 158 refused = 0; 159 ai = res; 160 goto retry; 161 } 162 freeaddrinfo(res); 163 return(-1); 164 } 165 freeaddrinfo(res); 166 return(s); 167 } 168 169 /* 170 * Figure out whether the local machine is the same 171 * as the remote machine (RM) entry (if it exists). 172 * We do this by counting the intersection of our 173 * address list and theirs. This is better than the 174 * old method (comparing the canonical names), as it 175 * allows load-sharing between multiple print servers. 176 * The return value is an error message which must be 177 * free()d. 178 */ 179 char * 180 checkremote(struct printer *pp) 181 { 182 char lclhost[MAXHOSTNAMELEN]; 183 struct addrinfo hints, *local_res, *remote_res, *lr, *rr; 184 char *error; 185 int ncommonaddrs, errno; 186 char h1[NI_MAXHOST], h2[NI_MAXHOST]; 187 188 if (!pp->rp_matches_local) { /* Remote printer doesn't match local */ 189 pp->remote = 1; 190 return NULL; 191 } 192 193 pp->remote = 0; /* assume printer is local */ 194 if (pp->remote_host == NULL) 195 return NULL; 196 197 /* get the addresses of the local host */ 198 gethostname(lclhost, sizeof(lclhost)); 199 lclhost[sizeof(lclhost) - 1] = '\0'; 200 201 memset(&hints, 0, sizeof(hints)); 202 hints.ai_family = family; 203 hints.ai_socktype = SOCK_STREAM; 204 hints.ai_flags = AI_PASSIVE; 205 if ((errno = getaddrinfo(lclhost, NULL, &hints, &local_res)) != 0) { 206 asprintf(&error, "unable to get official name " 207 "for local machine %s: %s", 208 lclhost, gai_strerror(errno)); 209 return error; 210 } 211 212 /* get the official name of RM */ 213 memset(&hints, 0, sizeof(hints)); 214 hints.ai_family = family; 215 hints.ai_socktype = SOCK_STREAM; 216 hints.ai_flags = AI_PASSIVE; 217 if ((errno = getaddrinfo(pp->remote_host, NULL, 218 &hints, &remote_res)) != 0) { 219 asprintf(&error, "unable to get address list for " 220 "remote machine %s: %s", 221 pp->remote_host, gai_strerror(errno)); 222 freeaddrinfo(local_res); 223 return error; 224 } 225 226 ncommonaddrs = 0; 227 for (lr = local_res; lr; lr = lr->ai_next) { 228 h1[0] = '\0'; 229 if (getnameinfo(lr->ai_addr, lr->ai_addrlen, h1, sizeof(h1), 230 NULL, 0, NI_NUMERICHOST) != 0) 231 continue; 232 for (rr = remote_res; rr; rr = rr->ai_next) { 233 h2[0] = '\0'; 234 if (getnameinfo(rr->ai_addr, rr->ai_addrlen, 235 h2, sizeof(h2), NULL, 0, 236 NI_NUMERICHOST) != 0) 237 continue; 238 if (strcmp(h1, h2) == 0) 239 ncommonaddrs++; 240 } 241 } 242 243 /* 244 * if the two hosts do not share at least one IP address 245 * then the printer must be remote. 246 */ 247 if (ncommonaddrs == 0) 248 pp->remote = 1; 249 freeaddrinfo(local_res); 250 freeaddrinfo(remote_res); 251 return NULL; 252 } 253 254 /* 255 * This isn't really network-related, but it's used here to write 256 * multi-part strings onto sockets without using stdio. Return 257 * values are as for writev(2). 258 */ 259 ssize_t 260 writel(int strm, ...) 261 { 262 va_list ap; 263 int i, n; 264 const char *cp; 265 #define NIOV 12 266 struct iovec iov[NIOV], *iovp = iov; 267 ssize_t retval; 268 269 /* first count them */ 270 va_start(ap, strm); 271 n = 0; 272 do { 273 cp = va_arg(ap, char *); 274 n++; 275 } while (cp); 276 va_end(ap); 277 n--; /* correct for count of trailing null */ 278 279 if (n > NIOV) { 280 iovp = malloc(n * sizeof *iovp); 281 if (iovp == NULL) 282 return -1; 283 } 284 285 /* now make up iovec and send */ 286 va_start(ap, strm); 287 for (i = 0; i < n; i++) { 288 iovp[i].iov_base = va_arg(ap, char *); 289 iovp[i].iov_len = strlen(iovp[i].iov_base); 290 } 291 va_end(ap); 292 retval = writev(strm, iovp, n); 293 if (iovp != iov) 294 free(iovp); 295 return retval; 296 } 297