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 * From: @(#)common.c 8.5 (Berkeley) 4/28/95 41 */ 42 43 #include "lp.cdefs.h" /* A cross-platform version of <sys/cdefs.h> */ 44 #include <sys/param.h> 45 #include <sys/socket.h> 46 #include <sys/stat.h> 47 #include <sys/time.h> 48 #include <sys/uio.h> 49 50 #include <netinet/in.h> 51 #include <arpa/inet.h> 52 #include <netdb.h> 53 54 #include <dirent.h> /* required for lp.h, not used here */ 55 #include <err.h> 56 #include <errno.h> 57 #include <stdarg.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "lp.h" 64 #include "lp.local.h" 65 #include "pathnames.h" 66 67 /* 68 * 'local_host' is always the hostname of the machine which is running 69 * lpr (lpd, whatever), while 'from_host' either points at 'local_host' 70 * or points at a different buffer when receiving a job from a remote 71 * machine (and that buffer has the hostname of that remote machine). 72 */ 73 char local_host[MAXHOSTNAMELEN]; /* host running lpd/lpr */ 74 const char *from_host = local_host; /* client's machine name */ 75 const char *from_ip = ""; /* client machine's IP address */ 76 77 #ifdef INET6 78 u_char family = PF_UNSPEC; 79 #else 80 u_char family = PF_INET; 81 #endif 82 83 /* 84 * Create a TCP connection to host "rhost" at port "rport". 85 * If rport == 0, then use the printer service port. 86 * Most of this code comes from rcmd.c. 87 */ 88 int 89 getport(const struct printer *pp, const char *rhost, int rport) 90 { 91 struct addrinfo hints, *res, *ai; 92 int s, timo = 1, lport = IPPORT_RESERVED - 1; 93 int error, refused = 0; 94 95 /* 96 * Get the host address and port number to connect to. 97 */ 98 if (rhost == NULL) 99 fatal(pp, "no remote host to connect to"); 100 memset(&hints, 0, sizeof(hints)); 101 hints.ai_family = family; 102 hints.ai_socktype = SOCK_STREAM; 103 hints.ai_protocol = 0; 104 error = getaddrinfo(rhost, (rport == 0 ? "printer" : NULL), 105 &hints, &res); 106 if (error) 107 fatal(pp, "%s\n", gai_strerror(error)); 108 if (rport != 0) 109 ((struct sockaddr_in *) res->ai_addr)->sin_port = htons(rport); 110 111 /* 112 * Try connecting to the server. 113 */ 114 ai = res; 115 retry: 116 PRIV_START 117 s = rresvport_af(&lport, ai->ai_family); 118 PRIV_END 119 if (s < 0) { 120 if (errno != EAGAIN) { 121 if (ai->ai_next) { 122 ai = ai->ai_next; 123 goto retry; 124 } 125 if (refused && timo <= 16) { 126 sleep(timo); 127 timo *= 2; 128 refused = 0; 129 ai = res; 130 goto retry; 131 } 132 } 133 freeaddrinfo(res); 134 return(-1); 135 } 136 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) { 137 error = errno; 138 (void) close(s); 139 errno = error; 140 /* 141 * This used to decrement lport, but the current semantics 142 * of rresvport do not provide such a function (in fact, 143 * rresvport should guarantee that the chosen port will 144 * never result in an EADDRINUSE). 145 */ 146 if (errno == EADDRINUSE) { 147 goto retry; 148 } 149 150 if (errno == ECONNREFUSED) 151 refused++; 152 153 if (ai->ai_next != NULL) { 154 ai = ai->ai_next; 155 goto retry; 156 } 157 if (refused && timo <= 16) { 158 sleep(timo); 159 timo *= 2; 160 refused = 0; 161 ai = res; 162 goto retry; 163 } 164 freeaddrinfo(res); 165 return(-1); 166 } 167 freeaddrinfo(res); 168 return(s); 169 } 170 171 /* 172 * Figure out whether the local machine is the same 173 * as the remote machine (RM) entry (if it exists). 174 * We do this by counting the intersection of our 175 * address list and theirs. This is better than the 176 * old method (comparing the canonical names), as it 177 * allows load-sharing between multiple print servers. 178 * The return value is an error message which must be 179 * free()d. 180 */ 181 char * 182 checkremote(struct printer *pp) 183 { 184 char lclhost[MAXHOSTNAMELEN]; 185 struct addrinfo hints, *local_res, *remote_res, *lr, *rr; 186 char *error; 187 int ncommonaddrs, errno; 188 char h1[NI_MAXHOST], h2[NI_MAXHOST]; 189 190 if (!pp->rp_matches_local) { /* Remote printer doesn't match local */ 191 pp->remote = 1; 192 return NULL; 193 } 194 195 pp->remote = 0; /* assume printer is local */ 196 if (pp->remote_host == NULL) 197 return NULL; 198 199 /* get the addresses of the local host */ 200 gethostname(lclhost, sizeof(lclhost)); 201 lclhost[sizeof(lclhost) - 1] = '\0'; 202 203 memset(&hints, 0, sizeof(hints)); 204 hints.ai_family = family; 205 hints.ai_socktype = SOCK_STREAM; 206 hints.ai_flags = AI_PASSIVE; 207 if ((errno = getaddrinfo(lclhost, NULL, &hints, &local_res)) != 0) { 208 asprintf(&error, "unable to get official name " 209 "for local machine %s: %s", 210 lclhost, gai_strerror(errno)); 211 return error; 212 } 213 214 /* get the official name of RM */ 215 memset(&hints, 0, sizeof(hints)); 216 hints.ai_family = family; 217 hints.ai_socktype = SOCK_STREAM; 218 hints.ai_flags = AI_PASSIVE; 219 if ((errno = getaddrinfo(pp->remote_host, NULL, 220 &hints, &remote_res)) != 0) { 221 asprintf(&error, "unable to get address list for " 222 "remote machine %s: %s", 223 pp->remote_host, gai_strerror(errno)); 224 freeaddrinfo(local_res); 225 return error; 226 } 227 228 ncommonaddrs = 0; 229 for (lr = local_res; lr; lr = lr->ai_next) { 230 h1[0] = '\0'; 231 if (getnameinfo(lr->ai_addr, lr->ai_addrlen, h1, sizeof(h1), 232 NULL, 0, NI_NUMERICHOST) != 0) 233 continue; 234 for (rr = remote_res; rr; rr = rr->ai_next) { 235 h2[0] = '\0'; 236 if (getnameinfo(rr->ai_addr, rr->ai_addrlen, 237 h2, sizeof(h2), NULL, 0, 238 NI_NUMERICHOST) != 0) 239 continue; 240 if (strcmp(h1, h2) == 0) 241 ncommonaddrs++; 242 } 243 } 244 245 /* 246 * if the two hosts do not share at least one IP address 247 * then the printer must be remote. 248 */ 249 if (ncommonaddrs == 0) 250 pp->remote = 1; 251 freeaddrinfo(local_res); 252 freeaddrinfo(remote_res); 253 return NULL; 254 } 255 256 /* 257 * This isn't really network-related, but it's used here to write 258 * multi-part strings onto sockets without using stdio. Return 259 * values are as for writev(2). 260 */ 261 ssize_t 262 writel(int strm, ...) 263 { 264 va_list ap; 265 int i, n; 266 const char *cp; 267 #define NIOV 12 268 struct iovec iov[NIOV], *iovp = iov; 269 ssize_t retval; 270 271 /* first count them */ 272 va_start(ap, strm); 273 n = 0; 274 do { 275 cp = va_arg(ap, char *); 276 n++; 277 } while (cp); 278 va_end(ap); 279 n--; /* correct for count of trailing null */ 280 281 if (n > NIOV) { 282 iovp = malloc(n * sizeof *iovp); 283 if (iovp == NULL) 284 return -1; 285 } 286 287 /* now make up iovec and send */ 288 va_start(ap, strm); 289 for (i = 0; i < n; i++) { 290 iovp[i].iov_base = va_arg(ap, char *); 291 iovp[i].iov_len = strlen(iovp[i].iov_base); 292 } 293 va_end(ap); 294 retval = writev(strm, iovp, n); 295 if (iovp != iov) 296 free(iovp); 297 return retval; 298 } 299