1 /*
2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * From: @(#)common.c 8.5 (Berkeley) 4/28/95
39 */
40
41 #include "lp.cdefs.h" /* A cross-platform version of <sys/cdefs.h> */
42 __FBSDID("$FreeBSD$");
43
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
getport(const struct printer * pp,const char * rhost,int rport)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 *
checkremote(struct printer * pp)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
writel(int strm,...)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 == 0)
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