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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * From: @(#)common.c 8.5 (Berkeley) 4/28/95
35 *
36 * $FreeBSD: src/usr.sbin/lpr/common_source/net.c,v 1.3.2.4 2001/06/25 01:00:56 gad Exp $
37 */
38
39 #include <sys/param.h>
40 #include <sys/socket.h>
41 #include <sys/stat.h>
42 #include <sys/time.h>
43 #include <sys/uio.h>
44
45 #include <netinet/in.h>
46 #include <arpa/inet.h>
47 #include <netdb.h>
48
49 #include <dirent.h> /* required for lp.h, not used here */
50 #include <errno.h>
51 #include <stdarg.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56
57 #include "lp.h"
58 #include "lp.local.h"
59 #include "pathnames.h"
60
61 /*
62 * 'local_host' is always the hostname of the machine which is running
63 * lpr (lpd, whatever), while 'from_host' either points at 'local_host'
64 * or points at a different buffer when receiving a job from a remote
65 * machine (and that buffer has the hostname of that remote machine).
66 */
67 char local_host[MAXHOSTNAMELEN]; /* host running lpd/lpr */
68 const char *from_host = local_host; /* client's machine name */
69 const char *from_ip = ""; /* client machine's IP address */
70
71 #ifdef INET6
72 u_char family = PF_UNSPEC;
73 #else
74 u_char family = PF_INET;
75 #endif
76
77 extern uid_t uid, euid;
78
79 /*
80 * Create a TCP connection to host "rhost" at port "rport".
81 * If rport == 0, then use the printer service port.
82 * Most of this code comes from rcmd.c.
83 */
84 int
getport(const struct printer * pp,const char * rhost,int rport)85 getport(const struct printer *pp, const char *rhost, int rport)
86 {
87 struct addrinfo hints, *res, *ai;
88 int s, timo = 1, lport = IPPORT_RESERVED - 1;
89 int err, refused = 0;
90
91 /*
92 * Get the host address and port number to connect to.
93 */
94 if (rhost == NULL)
95 fatal(pp, "no remote host to connect to");
96 memset(&hints, 0, sizeof(hints));
97 hints.ai_family = family;
98 hints.ai_socktype = SOCK_STREAM;
99 hints.ai_protocol = 0;
100 err = getaddrinfo(rhost, (rport == 0 ? "printer" : NULL),
101 &hints, &res);
102 if (err)
103 fatal(pp, "%s\n", gai_strerror(err));
104 if (rport != 0)
105 ((struct sockaddr_in *) res->ai_addr)->sin_port = htons(rport);
106
107 /*
108 * Try connecting to the server.
109 */
110 ai = res;
111 retry:
112 seteuid(euid);
113 s = rresvport_af(&lport, ai->ai_family);
114 seteuid(uid);
115 if (s < 0) {
116 if (errno != EAGAIN) {
117 if (ai->ai_next) {
118 ai = ai->ai_next;
119 goto retry;
120 }
121 if (refused && timo <= 16) {
122 sleep(timo);
123 timo *= 2;
124 refused = 0;
125 ai = res;
126 goto retry;
127 }
128 }
129 freeaddrinfo(res);
130 return(-1);
131 }
132 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
133 err = errno;
134 close(s);
135 errno = err;
136 /*
137 * This used to decrement lport, but the current semantics
138 * of rresvport do not provide such a function (in fact,
139 * rresvport should guarantee that the chosen port will
140 * never result in an EADDRINUSE).
141 */
142 if (errno == EADDRINUSE) {
143 goto retry;
144 }
145
146 if (errno == ECONNREFUSED)
147 refused++;
148
149 if (ai->ai_next != NULL) {
150 ai = ai->ai_next;
151 goto retry;
152 }
153 if (refused && timo <= 16) {
154 sleep(timo);
155 timo *= 2;
156 refused = 0;
157 ai = res;
158 goto retry;
159 }
160 freeaddrinfo(res);
161 return(-1);
162 }
163 freeaddrinfo(res);
164 return(s);
165 }
166
167 /*
168 * Figure out whether the local machine is the same
169 * as the remote machine (RM) entry (if it exists).
170 * We do this by counting the intersection of our
171 * address list and theirs. This is better than the
172 * old method (comparing the canonical names), as it
173 * allows load-sharing between multiple print servers.
174 * The return value is an error message which must be
175 * free()d.
176 */
177 char *
checkremote(struct printer * pp)178 checkremote(struct printer *pp)
179 {
180 char lclhost[MAXHOSTNAMELEN];
181 struct addrinfo hints, *local_res, *remote_res, *lr, *rr;
182 char *err;
183 int ncommonaddrs, error;
184 char h1[NI_MAXHOST], h2[NI_MAXHOST];
185
186 if (!pp->rp_matches_local) { /* Remote printer doesn't match local */
187 pp->remote = 1;
188 return NULL;
189 }
190
191 pp->remote = 0; /* assume printer is local */
192 if (pp->remote_host == NULL)
193 return NULL;
194
195 /* get the addresses of the local host */
196 gethostname(lclhost, sizeof(lclhost));
197 lclhost[sizeof(lclhost) - 1] = '\0';
198
199 memset(&hints, 0, sizeof(hints));
200 hints.ai_family = family;
201 hints.ai_socktype = SOCK_STREAM;
202 hints.ai_flags = AI_PASSIVE;
203 if ((error = getaddrinfo(lclhost, NULL, &hints, &local_res)) != 0) {
204 asprintf(&err, "unable to get official name "
205 "for local machine %s: %s",
206 lclhost, gai_strerror(error));
207 return err;
208 }
209
210 /* get the official name of RM */
211 memset(&hints, 0, sizeof(hints));
212 hints.ai_family = family;
213 hints.ai_socktype = SOCK_STREAM;
214 hints.ai_flags = AI_PASSIVE;
215 if ((error = getaddrinfo(pp->remote_host, NULL,
216 &hints, &remote_res)) != 0) {
217 asprintf(&err, "unable to get address list for "
218 "remote machine %s: %s",
219 pp->remote_host, gai_strerror(error));
220 freeaddrinfo(local_res);
221 return err;
222 }
223
224 ncommonaddrs = 0;
225 for (lr = local_res; lr; lr = lr->ai_next) {
226 h1[0] = '\0';
227 if (getnameinfo(lr->ai_addr, lr->ai_addrlen, h1, sizeof(h1),
228 NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
229 continue;
230 for (rr = remote_res; rr; rr = rr->ai_next) {
231 h2[0] = '\0';
232 if (getnameinfo(rr->ai_addr, rr->ai_addrlen,
233 h2, sizeof(h2), NULL, 0,
234 NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
235 continue;
236 if (strcmp(h1, h2) == 0)
237 ncommonaddrs++;
238 }
239 }
240
241 /*
242 * if the two hosts do not share at least one IP address
243 * then the printer must be remote.
244 */
245 if (ncommonaddrs == 0)
246 pp->remote = 1;
247 freeaddrinfo(local_res);
248 freeaddrinfo(remote_res);
249 return NULL;
250 }
251
252 /*
253 * This isn't really network-related, but it's used here to write
254 * multi-part strings onto sockets without using stdio. Return
255 * values are as for writev(2).
256 */
257 ssize_t
writel(int strm,...)258 writel(int strm, ...)
259 {
260 va_list ap;
261 int i, n;
262 const char *cp;
263 #define NIOV 12
264 struct iovec iov[NIOV], *iovp = iov;
265 ssize_t retval;
266
267 /* first count them */
268 va_start(ap, strm);
269 n = 0;
270 do {
271 cp = va_arg(ap, char *);
272 n++;
273 } while (cp);
274 va_end(ap);
275 n--; /* correct for count of trailing null */
276
277 if (n > NIOV) {
278 iovp = malloc(n * sizeof *iovp);
279 if (iovp == NULL)
280 return -1;
281 }
282
283 /* now make up iovec and send */
284 va_start(ap, strm);
285 for (i = 0; i < n; i++) {
286 iovp[i].iov_base = va_arg(ap, char *);
287 iovp[i].iov_len = strlen(iovp[i].iov_base);
288 }
289 va_end(ap);
290 retval = writev(strm, iovp, n);
291 if (iovp != iov)
292 free(iovp);
293 return retval;
294 }
295