xref: /illumos-gate/usr/src/lib/libslp/clib/slp_net_utils.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 1999 by Sun Microsystems, Inc.
24  * All rights reserved.
25  */
26 
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <syslog.h>
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <sys/sockio.h>
33 #include <arpa/inet.h>
34 #include <net/if.h>
35 #include <unistd.h>
36 #include <netdb.h>
37 #include <nss_dbdefs.h>
38 #include <slp-internal.h>
39 #include <slp_net_utils.h>
40 
41 typedef struct slp_ifinfo {
42 	struct sockaddr_in addr;
43 	struct sockaddr_in netmask;
44 	struct sockaddr_in bc_addr;
45 	short flags;
46 } slp_ifinfo_t;
47 
48 typedef struct slp_handle_ifinfo {
49 	slp_ifinfo_t *all_ifs;
50 	int numifs;
51 } slp_handle_ifinfo_t;
52 
53 
54 static SLPError get_all_interfaces(slp_handle_ifinfo_t *info);
55 
56 /*
57  * Obtains the broadcast addresses for all local interfaces given in
58  * addrs.
59  *
60  * hp		IN / OUT holds cached-per-handle if info
61  * given_ifs	IN	an array of local interfaces
62  * num_givenifs	IN	number of addresses in given_ifs
63  * bc_addrs	OUT	an array of broadcast addresses for local interfaces
64  * num_addrs	OUT	number of addrs returned in bc_addrs
65  *
66  * Returns SLP_OK if at least one broadcast address was found; if none
67  * were found, returns err != SLP_OK and *bc_addrs = NULL;
68  * Caller must free *bc_addrs when done.
69  */
70 SLPError slp_broadcast_addrs(slp_handle_impl_t *hp, struct in_addr *given_ifs,
71 				int num_givenifs,
72 				struct sockaddr_in *bc_addrs[],
73 				int *num_addrs) {
74 
75 	SLPError err;
76 	int i, j;
77 	slp_ifinfo_t *all_ifs;
78 	slp_handle_ifinfo_t *ifinfo;
79 	int numifs;
80 
81 	if (!hp->ifinfo) {
82 		if (!(ifinfo = malloc(sizeof (*ifinfo)))) {
83 			slp_err(LOG_CRIT, 0, "slp_broadcast_addrs",
84 				"out of memory");
85 			return (SLP_MEMORY_ALLOC_FAILED);
86 		}
87 		if ((err = get_all_interfaces(ifinfo)) != SLP_OK) {
88 			free(ifinfo);
89 			return (err);
90 		}
91 		hp->ifinfo = ifinfo;
92 	}
93 	all_ifs = ((slp_handle_ifinfo_t *)hp->ifinfo)->all_ifs;
94 	numifs = ((slp_handle_ifinfo_t *)hp->ifinfo)->numifs;
95 
96 	/* allocate memory for reply */
97 	if (!(*bc_addrs = calloc(num_givenifs, sizeof (**bc_addrs)))) {
98 		slp_err(LOG_CRIT, 0, "slp_broadcast_addrs", "out of memory");
99 		return (SLP_MEMORY_ALLOC_FAILED);
100 	}
101 
102 	/* copy bc addrs for all desired interfaces which are bc-enabled */
103 	*num_addrs = 0;
104 	for (j = 0; j < num_givenifs; j++) {
105 	    for (i = 0; i < numifs; i++) {
106 
107 		if (!(all_ifs[i].flags & IFF_BROADCAST)) {
108 			continue;
109 		}
110 
111 		if (memcmp(&(all_ifs[i].addr.sin_addr.s_addr),
112 			    &(given_ifs[j].s_addr),
113 			    sizeof (given_ifs[j].s_addr)) == 0 &&
114 		    all_ifs[i].bc_addr.sin_addr.s_addr != 0) {
115 
116 		    /* got it, so copy it to bc_addrs */
117 		    (void) memcpy(
118 				    *bc_addrs + *num_addrs,
119 				    &(all_ifs[i].bc_addr),
120 				    sizeof (all_ifs[i].bc_addr));
121 		    (*num_addrs)++;
122 
123 		    break;
124 		}
125 	    }
126 	}
127 
128 	if (*num_addrs == 0) {
129 		/* none found */
130 		free (*bc_addrs);
131 		bc_addrs = NULL;
132 		return (SLP_INTERNAL_SYSTEM_ERROR);
133 	}
134 	return (SLP_OK);
135 }
136 
137 /*
138  * Returns true if addr is on a subnet local to the local host.
139  */
140 SLPBoolean slp_on_subnet(slp_handle_impl_t *hp, struct in_addr addr) {
141 	int i;
142 	struct in_addr netmask, net_addr, masked_addr;
143 	slp_ifinfo_t *all_ifs;
144 	slp_handle_ifinfo_t *ifinfo;
145 	int numifs;
146 
147 	if (!hp->ifinfo) {
148 		if (!(ifinfo = malloc(sizeof (*ifinfo)))) {
149 			slp_err(LOG_CRIT, 0, "slp_broadcast_addrs",
150 				"out of memory");
151 			return (SLP_FALSE);
152 		}
153 		if (get_all_interfaces(ifinfo) != SLP_OK) {
154 			free(ifinfo);
155 			return (SLP_FALSE);
156 		}
157 		hp->ifinfo = ifinfo;
158 	}
159 	all_ifs = ((slp_handle_ifinfo_t *)hp->ifinfo)->all_ifs;
160 	numifs = ((slp_handle_ifinfo_t *)hp->ifinfo)->numifs;
161 
162 	for (i = 0; i < numifs; i++) {
163 		/* get netmask */
164 		netmask.s_addr = all_ifs[i].netmask.sin_addr.s_addr;
165 		/* get network address */
166 		net_addr.s_addr =
167 			all_ifs[i].addr.sin_addr.s_addr & netmask.s_addr;
168 		/* apply netmask to input addr */
169 		masked_addr.s_addr = addr.s_addr & netmask.s_addr;
170 
171 		if (memcmp(&(masked_addr.s_addr), &(net_addr.s_addr),
172 				sizeof (net_addr.s_addr)) == 0) {
173 			return (SLP_TRUE);
174 		}
175 	}
176 
177 	return (SLP_FALSE);
178 }
179 
180 /*
181  * Returns true if any local interface if configured with addr.
182  */
183 SLPBoolean slp_on_localhost(slp_handle_impl_t *hp, struct in_addr addr) {
184 	int i;
185 	slp_ifinfo_t *all_ifs;
186 	slp_handle_ifinfo_t *ifinfo;
187 	int numifs;
188 
189 	if (!hp->ifinfo) {
190 		if (!(ifinfo = malloc(sizeof (*ifinfo)))) {
191 			slp_err(LOG_CRIT, 0, "slp_broadcast_addrs",
192 				"out of memory");
193 			return (SLP_FALSE);
194 		}
195 		if (get_all_interfaces(ifinfo) != SLP_OK) {
196 			free(ifinfo);
197 			return (SLP_FALSE);
198 		}
199 		hp->ifinfo = ifinfo;
200 	}
201 	all_ifs = ((slp_handle_ifinfo_t *)hp->ifinfo)->all_ifs;
202 	numifs = ((slp_handle_ifinfo_t *)hp->ifinfo)->numifs;
203 
204 	for (i = 0; i < numifs; i++) {
205 		if (memcmp(&(addr.s_addr), &(all_ifs[i].addr.sin_addr.s_addr),
206 				sizeof (addr)) == 0) {
207 
208 			return (SLP_TRUE);
209 		}
210 	}
211 
212 	return (SLP_FALSE);
213 }
214 
215 void slp_free_ifinfo(void *hi) {
216 	free(((slp_handle_ifinfo_t *)hi)->all_ifs);
217 }
218 
219 /*
220  * Populates all_ifs.
221  */
222 static SLPError get_all_interfaces(slp_handle_ifinfo_t *info) {
223 	int i, n, s = 0;
224 	int numifs;
225 	char *buf = NULL;
226 	size_t bufsize;
227 	struct ifconf ifc;
228 	struct ifreq *ifrp, ifr;
229 	slp_ifinfo_t *all_ifs = NULL;
230 	SLPError err = SLP_OK;
231 
232 	/* create a socket with which to get interface info */
233 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
234 		goto cleanup;
235 	}
236 
237 	/* how many interfaces are configured? */
238 	if (ioctl(s, SIOCGIFNUM, (char *)&numifs) < 0) {
239 		goto cleanup;
240 	}
241 
242 	/* allocate memory for ifinfo_t array */
243 	if (!(all_ifs = calloc(numifs, sizeof (*all_ifs)))) {
244 		slp_err(LOG_CRIT, 0, "get_all_interfaces", "out of memory");
245 		err = SLP_MEMORY_ALLOC_FAILED;
246 		goto cleanup;
247 	}
248 
249 	/* allocate memory for interface info */
250 	bufsize = numifs * sizeof (struct ifreq);
251 	if (!(buf = malloc(bufsize))) {
252 		slp_err(LOG_CRIT, 0, "get_all_interfaces", "out of memory");
253 		err = SLP_MEMORY_ALLOC_FAILED;
254 		goto cleanup;
255 	}
256 
257 	/* get if info */
258 	ifc.ifc_len = bufsize;
259 	ifc.ifc_buf = buf;
260 	if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) {
261 		goto cleanup;
262 	}
263 
264 	ifrp = ifc.ifc_req;
265 	i = 0;
266 	for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifrp++) {
267 
268 	    /* ignore if interface is not up */
269 	    (void) memset((char *)&ifr, 0, sizeof (ifr));
270 	    (void) strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof (ifr.ifr_name));
271 	    if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
272 		continue;
273 	    }
274 	    if (!(ifr.ifr_flags & IFF_UP)) {
275 		continue;
276 	    }
277 
278 	    all_ifs[i].flags = ifr.ifr_flags;
279 
280 	    /* get the interface's address */
281 	    if (ioctl(s, SIOCGIFADDR, (caddr_t)&ifr) < 0) {
282 		continue;
283 	    }
284 
285 	    (void) memcpy(&(all_ifs[i].addr), &ifr.ifr_addr,
286 				sizeof (all_ifs[i].addr));
287 
288 	    /* get the interface's broadcast address */
289 	    if (ioctl(s, SIOCGIFBRDADDR, (caddr_t)&ifr) < 0) {
290 		(void) memset(&(all_ifs[i].bc_addr), 0,
291 				sizeof (all_ifs[i].bc_addr));
292 	    } else {
293 		(void) memcpy(&(all_ifs[i].bc_addr), &ifr.ifr_addr,
294 				sizeof (all_ifs[i].bc_addr));
295 	    }
296 
297 	    /* get the interface's subnet mask */
298 	    if (ioctl(s, SIOCGIFNETMASK, (caddr_t)&ifr) < 0) {
299 		(void) memset(&(all_ifs[i].netmask), 0,
300 				sizeof (all_ifs[i].netmask));
301 	    } else {
302 		(void) memcpy(&(all_ifs[i].netmask), &ifr.ifr_addr,
303 				sizeof (all_ifs[i].netmask));
304 	    }
305 
306 	    i++;
307 	}
308 
309 	/* i contains the number we actually got info on */
310 	info->numifs = i;
311 	info->all_ifs = all_ifs;
312 
313 	if (i == 0) {
314 		err = SLP_INTERNAL_SYSTEM_ERROR;
315 		free(all_ifs);
316 		info->all_ifs = NULL;
317 	}
318 
319 cleanup:
320 	if (s) (void) close(s);
321 	if (buf) free(buf);
322 
323 	return (err);
324 }
325 
326 /*
327  * Converts a SLPSrvURL to a network address. 'sa' must have been
328  * allocated by the caller.
329  * Assumes that addresses are given as specified in the protocol spec,
330  * i.e. as IP addresses and not host names.
331  */
332 SLPError slp_surl2sin(SLPSrvURL *surl, struct sockaddr_in *sa) {
333 	struct sockaddr_in *sin = (struct sockaddr_in *)sa;
334 
335 	if (slp_pton(surl->s_pcHost, &(sin->sin_addr)) < 1)
336 		return (SLP_PARAMETER_BAD);
337 	sin->sin_family = AF_INET;
338 	/* port number */
339 	sin->sin_port = htons(
340 		(surl->s_iPort == 0 ? SLP_PORT : surl->s_iPort));
341 
342 	return (SLP_OK);
343 }
344 
345 /*
346  * A wrapper around gethostbyaddr_r. This checks the useGetXXXbyYYY
347  * property first to determine whether a name service lookup should
348  * be used. If not, it converts the address in 'addr' to a string
349  * and just returns that.
350  *
351  * The core functionality herein will be replaced with getaddrinfo
352  * when it becomes available.
353  */
354 
355 char *slp_gethostbyaddr(const char *addr, int size) {
356 	char storebuf[SLP_NETDB_BUFSZ], addrbuf[INET6_ADDRSTRLEN], *cname;
357 	const char *use_xbyy;
358 	struct hostent namestruct[1], *name;
359 	int herrno;
360 
361 	/* default: copy in the IP address */
362 	cname = slp_ntop(addrbuf, INET6_ADDRSTRLEN, (const void *) addr);
363 	if (cname && !(cname = strdup(cname))) {
364 		slp_err(LOG_CRIT, 0, "slp_gethostbyaddr", "out of memory");
365 		return (NULL);
366 	}
367 
368 	if ((use_xbyy = SLPGetProperty(SLP_CONFIG_USEGETXXXBYYYY)) != NULL &&
369 	    strcasecmp(use_xbyy, "false") == 0) {
370 		return (cname);
371 	}
372 
373 	while (!(name = gethostbyaddr_r(addr, size,
374 					AF_INET,
375 					namestruct,
376 					storebuf,
377 					SLP_NETDB_BUFSZ,
378 					&herrno))) {
379 		switch (herrno) {
380 		case NO_RECOVERY:
381 		case NO_DATA:
382 			return (cname);
383 		case TRY_AGAIN:
384 			continue;
385 		default:
386 			return (cname);	/* IP address */
387 		}
388 	}
389 
390 	free(cname);
391 	if (!(cname = strdup(name->h_name))) {
392 		slp_err(LOG_CRIT, 0, "slp_gethostbyaddr", "out of memory");
393 		return (NULL);
394 	}
395 
396 	return (cname);
397 }
398 
399 /* @@@ currently getting these from libresolv2 -> change? */
400 
401 /*
402  * Converts the address pointed to by 'addr' to a string. Currently
403  * just calls inet_ntoa, but is structured to be a wrapper to
404  * inet_ntop. Returns NULL on failure.
405  *
406  * This wrapper allows callers to be protocol agnostic. Right now it
407  * only handles IPv4.
408  */
409 /*ARGSUSED*/
410 char *slp_ntop(char *buf, int buflen, const void *addr) {
411 	return (inet_ntoa(*(struct in_addr *)addr));
412 }
413 
414 /*
415  * convert from presentation format (which usually means ASCII printable)
416  * to network format (which is usually some kind of binary format).
417  * return:
418  *	1 if the address was valid for the specified address family
419  *	0 if the address wasn't valid (`dst' is untouched in this case)
420  *	-1 if some other error occurred (`dst' is untouched in this case, too)
421  *
422  * This wrapper allows callers to be protocol agnostic. Right now it
423  * only handles IPv4.
424  */
425 int slp_pton(const char *addrstr, void *addr) {
426 	return (inet_pton(AF_INET, addrstr, addr));
427 }
428