1/*-
2 * Copyright (c) 1994, Garrett Wollman
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD: stable/11/lib/libc/net/getnetnamadr.c 360415 2020-04-27 23:49:13Z brooks $");
28
29#include "namespace.h"
30#include "reentrant.h"
31#include <sys/param.h>
32#include <sys/socket.h>
33#include <netinet/in.h>
34#include <arpa/inet.h>
35#include <netdb.h>
36#include <stdio.h>
37#include <ctype.h>
38#include <errno.h>
39#include <stdlib.h>
40#include <string.h>
41#include <stdarg.h>
42#include <nsswitch.h>
43#include "un-namespace.h"
44#include "netdb_private.h"
45#ifdef NS_CACHING
46#include "nscache.h"
47#endif
48
49/* Network lookup order if nsswitch.conf is broken or nonexistent */
50static const ns_src default_src[] = {
51	{ NSSRC_FILES, NS_SUCCESS },
52	{ NSSRC_DNS, NS_SUCCESS },
53	{ 0 }
54};
55
56NETDB_THREAD_ALLOC(netent_data)
57NETDB_THREAD_ALLOC(netdata)
58
59#ifdef NS_CACHING
60static int
61net_id_func(char *buffer, size_t *buffer_size, va_list ap, void *cache_mdata)
62{
63	char *name;
64	uint32_t net;
65	int type;
66
67	size_t desired_size, size;
68	enum nss_lookup_type lookup_type;
69	int res = NS_UNAVAIL;
70
71	lookup_type = (enum nss_lookup_type)(uintptr_t)cache_mdata;
72	switch (lookup_type) {
73	case nss_lt_name:
74		name = va_arg(ap, char *);
75
76		size = strlen(name);
77		desired_size = sizeof(enum nss_lookup_type) + size + 1;
78		if (desired_size > *buffer_size) {
79			res = NS_RETURN;
80			goto fin;
81		}
82
83		memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
84		memcpy(buffer + sizeof(enum nss_lookup_type), name, size + 1);
85
86		res = NS_SUCCESS;
87		break;
88	case nss_lt_id:
89		net = va_arg(ap, uint32_t);
90		type = va_arg(ap, int);
91
92		desired_size = sizeof(enum nss_lookup_type) +
93		    sizeof(uint32_t) + sizeof(int);
94		if (desired_size > *buffer_size) {
95			res = NS_RETURN;
96			goto fin;
97		}
98
99		memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
100		memcpy(buffer + sizeof(enum nss_lookup_type), &net,
101		    sizeof(uint32_t));
102		memcpy(buffer + sizeof(enum nss_lookup_type) + sizeof(uint32_t),
103		    &type, sizeof(int));
104
105		res = NS_SUCCESS;
106		break;
107	default:
108		/* should be unreachable */
109		return (NS_UNAVAIL);
110	}
111
112fin:
113	*buffer_size = desired_size;
114	return (res);
115}
116
117
118static int
119net_marshal_func(char *buffer, size_t *buffer_size, void *retval, va_list ap,
120    void *cache_mdata)
121{
122	char *name;
123	uint32_t net;
124	int type;
125	struct netent *ne;
126	char *orig_buf;
127	size_t orig_buf_size;
128
129	struct netent new_ne;
130	size_t desired_size, size, aliases_size;
131	char *p;
132	char **alias;
133
134	switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) {
135	case nss_lt_name:
136		name = va_arg(ap, char *);
137		break;
138	case nss_lt_id:
139		net = va_arg(ap, uint32_t);
140		type = va_arg(ap, int);
141	break;
142	case nss_lt_all:
143		break;
144	default:
145		/* should be unreachable */
146		return (NS_UNAVAIL);
147	}
148
149	ne = va_arg(ap, struct netent *);
150	orig_buf = va_arg(ap, char *);
151	orig_buf_size = va_arg(ap, size_t);
152
153	desired_size = _ALIGNBYTES + sizeof(struct netent) + sizeof(char *);
154	if (ne->n_name != NULL)
155		desired_size += strlen(ne->n_name) + 1;
156
157	if (ne->n_aliases != NULL) {
158		aliases_size = 0;
159		for (alias = ne->n_aliases; *alias; ++alias) {
160			desired_size += strlen(*alias) + 1;
161			++aliases_size;
162		}
163
164		desired_size += _ALIGNBYTES +
165		    (aliases_size + 1) * sizeof(char *);
166	}
167
168	if (*buffer_size < desired_size) {
169		/* this assignment is here for future use */
170		*buffer_size = desired_size;
171		return (NS_RETURN);
172	}
173
174	memcpy(&new_ne, ne, sizeof(struct netent));
175
176	*buffer_size = desired_size;
177	memset(buffer, 0, desired_size);
178	p = buffer + sizeof(struct netent) + sizeof(char *);
179	memcpy(buffer + sizeof(struct netent), &p, sizeof(char *));
180	p = (char *)_ALIGN(p);
181
182	if (new_ne.n_name != NULL) {
183		size = strlen(new_ne.n_name);
184		memcpy(p, new_ne.n_name, size);
185		new_ne.n_name = p;
186		p += size + 1;
187	}
188
189	if (new_ne.n_aliases != NULL) {
190		p = (char *)_ALIGN(p);
191		memcpy(p, new_ne.n_aliases, sizeof(char *) * aliases_size);
192		new_ne.n_aliases = (char **)p;
193		p += sizeof(char *) * (aliases_size + 1);
194
195		for (alias = new_ne.n_aliases; *alias; ++alias) {
196			size = strlen(*alias);
197			memcpy(p, *alias, size);
198			*alias = p;
199			p += size + 1;
200		}
201	}
202
203	memcpy(buffer, &new_ne, sizeof(struct netent));
204	return (NS_SUCCESS);
205}
206
207static int
208net_unmarshal_func(char *buffer, size_t buffer_size, void *retval, va_list ap,
209    void *cache_mdata)
210{
211	char *name;
212	uint32_t net;
213	int type;
214	struct netent *ne;
215	char *orig_buf;
216	size_t orig_buf_size;
217	int *ret_errno;
218
219	char *p;
220	char **alias;
221
222	switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) {
223	case nss_lt_name:
224		name = va_arg(ap, char *);
225		break;
226	case nss_lt_id:
227		net = va_arg(ap, uint32_t);
228		type = va_arg(ap, int);
229		break;
230	case nss_lt_all:
231		break;
232	default:
233		/* should be unreachable */
234		return (NS_UNAVAIL);
235	}
236
237	ne = va_arg(ap, struct netent *);
238	orig_buf = va_arg(ap, char *);
239	orig_buf_size = va_arg(ap, size_t);
240	ret_errno = va_arg(ap, int *);
241
242	if (orig_buf_size <
243	    buffer_size - sizeof(struct netent) - sizeof(char *)) {
244		*ret_errno = ERANGE;
245		return (NS_RETURN);
246	}
247
248	memcpy(ne, buffer, sizeof(struct netent));
249	memcpy(&p, buffer + sizeof(struct netent), sizeof(char *));
250
251	orig_buf = (char *)_ALIGN(orig_buf);
252	memcpy(orig_buf, buffer + sizeof(struct netent) + sizeof(char *) +
253	    _ALIGN(p) - (size_t)p,
254	    buffer_size - sizeof(struct netent) - sizeof(char *) -
255	    _ALIGN(p) + (size_t)p);
256	p = (char *)_ALIGN(p);
257
258	NS_APPLY_OFFSET(ne->n_name, orig_buf, p, char *);
259	if (ne->n_aliases != NULL) {
260		NS_APPLY_OFFSET(ne->n_aliases, orig_buf, p, char **);
261
262		for (alias = ne->n_aliases; *alias; ++alias)
263			NS_APPLY_OFFSET(*alias, orig_buf, p, char *);
264	}
265
266	if (retval != NULL)
267		*((struct netent **)retval) = ne;
268
269	return (NS_SUCCESS);
270}
271#endif /* NS_CACHING */
272
273static void
274netent_data_free(void *ptr)
275{
276	struct netent_data *ned = ptr;
277
278	if (ned == NULL)
279		return;
280	ned->stayopen = 0;
281	_endnethtent(ned);
282	free(ned);
283}
284
285static void
286netdata_free(void *ptr)
287{
288	free(ptr);
289}
290
291int
292__copy_netent(struct netent *ne, struct netent *nptr, char *buf, size_t buflen)
293{
294	char *cp;
295	int i, n;
296	int numptr, len;
297
298	/* Find out the amount of space required to store the answer. */
299	numptr = 1; /* NULL ptr */
300	len = (char *)ALIGN(buf) - buf;
301	for (i = 0; ne->n_aliases[i]; i++, numptr++) {
302		len += strlen(ne->n_aliases[i]) + 1;
303	}
304	len += strlen(ne->n_name) + 1;
305	len += numptr * sizeof(char*);
306
307	if (len > (int)buflen) {
308		errno = ERANGE;
309		return (-1);
310	}
311
312	/* copy net value and type */
313	nptr->n_addrtype = ne->n_addrtype;
314	nptr->n_net = ne->n_net;
315
316	cp = (char *)ALIGN(buf) + numptr * sizeof(char *);
317
318	/* copy official name */
319	n = strlen(ne->n_name) + 1;
320	strcpy(cp, ne->n_name);
321	nptr->n_name = cp;
322	cp += n;
323
324	/* copy aliases */
325	nptr->n_aliases = (char **)ALIGN(buf);
326	for (i = 0 ; ne->n_aliases[i]; i++) {
327		n = strlen(ne->n_aliases[i]) + 1;
328		strcpy(cp, ne->n_aliases[i]);
329		nptr->n_aliases[i] = cp;
330		cp += n;
331	}
332	nptr->n_aliases[i] = NULL;
333
334	return (0);
335}
336
337int
338getnetbyname_r(const char *name, struct netent *ne, char *buffer,
339    size_t buflen, struct netent **result, int *h_errorp)
340{
341#ifdef NS_CACHING
342	static const nss_cache_info cache_info =
343    		NS_COMMON_CACHE_INFO_INITIALIZER(
344		networks, (void *)nss_lt_name,
345		net_id_func, net_marshal_func, net_unmarshal_func);
346#endif
347	static const ns_dtab dtab[] = {
348		NS_FILES_CB(_ht_getnetbyname, NULL)
349		{ NSSRC_DNS, _dns_getnetbyname, NULL },
350		NS_NIS_CB(_nis_getnetbyname, NULL) /* force -DHESIOD */
351#ifdef NS_CACHING
352		NS_CACHE_CB(&cache_info)
353#endif
354		{ 0 }
355	};
356	int rval, ret_errno = 0;
357
358	rval = _nsdispatch((void *)result, dtab, NSDB_NETWORKS,
359	    "getnetbyname_r", default_src, name, ne, buffer, buflen,
360	    &ret_errno, h_errorp);
361
362	if (rval != NS_SUCCESS) {
363		errno = ret_errno;
364		return ((ret_errno != 0) ? ret_errno : -1);
365	}
366	return (0);
367}
368
369int
370getnetbyaddr_r(uint32_t addr, int af, struct netent *ne, char *buffer,
371    size_t buflen, struct netent **result, int *h_errorp)
372{
373#ifdef NS_CACHING
374	static const nss_cache_info cache_info =
375    		NS_COMMON_CACHE_INFO_INITIALIZER(
376		networks, (void *)nss_lt_id,
377		net_id_func, net_marshal_func, net_unmarshal_func);
378#endif
379	static const ns_dtab dtab[] = {
380		NS_FILES_CB(_ht_getnetbyaddr, NULL)
381		{ NSSRC_DNS, _dns_getnetbyaddr, NULL },
382		NS_NIS_CB(_nis_getnetbyaddr, NULL) /* force -DHESIOD */
383#ifdef NS_CACHING
384		NS_CACHE_CB(&cache_info)
385#endif
386		{ 0 }
387	};
388	int rval, ret_errno = 0;
389
390	rval = _nsdispatch((void *)result, dtab, NSDB_NETWORKS,
391	    "getnetbyaddr_r", default_src, addr, af, ne, buffer, buflen,
392	    &ret_errno, h_errorp);
393
394	if (rval != NS_SUCCESS) {
395		errno = ret_errno;
396		return ((ret_errno != 0) ? ret_errno : -1);
397	}
398	return (0);
399}
400
401struct netent *
402getnetbyname(const char *name)
403{
404	struct netdata *nd;
405	struct netent *rval;
406	int ret_h_errno;
407
408	if ((nd = __netdata_init()) == NULL)
409		return (NULL);
410	if (getnetbyname_r(name, &nd->net, nd->data, sizeof(nd->data), &rval,
411	    &ret_h_errno) != 0)
412		return (NULL);
413	return (rval);
414}
415
416struct netent *
417getnetbyaddr(uint32_t addr, int af)
418{
419	struct netdata *nd;
420	struct netent *rval;
421	int ret_h_errno;
422
423	if ((nd = __netdata_init()) == NULL)
424		return (NULL);
425	if (getnetbyaddr_r(addr, af, &nd->net, nd->data, sizeof(nd->data),
426	    &rval, &ret_h_errno) != 0)
427		return (NULL);
428	return (rval);
429}
430
431void
432setnetent(int stayopen)
433{
434	struct netent_data *ned;
435
436	if ((ned = __netent_data_init()) == NULL)
437		return;
438	_setnethtent(stayopen, ned);
439	_setnetdnsent(stayopen);
440}
441
442void
443endnetent(void)
444{
445	struct netent_data *ned;
446
447	if ((ned = __netent_data_init()) == NULL)
448		return;
449	_endnethtent(ned);
450	_endnetdnsent();
451}
452