1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1994, Garrett Wollman
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31#include "namespace.h"
32#include "reentrant.h"
33#include <sys/param.h>
34#include <sys/socket.h>
35#include <netinet/in.h>
36#include <arpa/inet.h>
37#include <netdb.h>
38#include <stdio.h>
39#include <ctype.h>
40#include <errno.h>
41#include <stdlib.h>
42#include <string.h>
43#include <stdarg.h>
44#include <nsswitch.h>
45#include "un-namespace.h"
46#include "netdb_private.h"
47#ifdef NS_CACHING
48#include "nscache.h"
49#endif
50
51/* Network lookup order if nsswitch.conf is broken or nonexistent */
52static const ns_src default_src[] = {
53	{ NSSRC_FILES, NS_SUCCESS },
54	{ NSSRC_DNS, NS_SUCCESS },
55	{ 0 }
56};
57
58NETDB_THREAD_ALLOC(netent_data)
59NETDB_THREAD_ALLOC(netdata)
60
61#ifdef NS_CACHING
62static int
63net_id_func(char *buffer, size_t *buffer_size, va_list ap, void *cache_mdata)
64{
65	char *name;
66	uint32_t net;
67	int type;
68
69	size_t desired_size, size;
70	enum nss_lookup_type lookup_type;
71	int res = NS_UNAVAIL;
72
73	lookup_type = (enum nss_lookup_type)(uintptr_t)cache_mdata;
74	switch (lookup_type) {
75	case nss_lt_name:
76		name = va_arg(ap, char *);
77
78		size = strlen(name);
79		desired_size = sizeof(enum nss_lookup_type) + size + 1;
80		if (desired_size > *buffer_size) {
81			res = NS_RETURN;
82			goto fin;
83		}
84
85		memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
86		memcpy(buffer + sizeof(enum nss_lookup_type), name, size + 1);
87
88		res = NS_SUCCESS;
89		break;
90	case nss_lt_id:
91		net = va_arg(ap, uint32_t);
92		type = va_arg(ap, int);
93
94		desired_size = sizeof(enum nss_lookup_type) +
95		    sizeof(uint32_t) + sizeof(int);
96		if (desired_size > *buffer_size) {
97			res = NS_RETURN;
98			goto fin;
99		}
100
101		memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
102		memcpy(buffer + sizeof(enum nss_lookup_type), &net,
103		    sizeof(uint32_t));
104		memcpy(buffer + sizeof(enum nss_lookup_type) + sizeof(uint32_t),
105		    &type, sizeof(int));
106
107		res = NS_SUCCESS;
108		break;
109	default:
110		/* should be unreachable */
111		return (NS_UNAVAIL);
112	}
113
114fin:
115	*buffer_size = desired_size;
116	return (res);
117}
118
119
120static int
121net_marshal_func(char *buffer, size_t *buffer_size, void *retval, va_list ap,
122    void *cache_mdata)
123{
124	char *name;
125	uint32_t net;
126	int type;
127	struct netent *ne;
128	char *orig_buf;
129	size_t orig_buf_size;
130
131	struct netent new_ne;
132	size_t desired_size, size, aliases_size;
133	char *p;
134	char **alias;
135
136	switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) {
137	case nss_lt_name:
138		name = va_arg(ap, char *);
139		break;
140	case nss_lt_id:
141		net = va_arg(ap, uint32_t);
142		type = va_arg(ap, int);
143	break;
144	case nss_lt_all:
145		break;
146	default:
147		/* should be unreachable */
148		return (NS_UNAVAIL);
149	}
150
151	ne = va_arg(ap, struct netent *);
152	orig_buf = va_arg(ap, char *);
153	orig_buf_size = va_arg(ap, size_t);
154
155	desired_size = _ALIGNBYTES + sizeof(struct netent) + sizeof(char *);
156	if (ne->n_name != NULL)
157		desired_size += strlen(ne->n_name) + 1;
158
159	if (ne->n_aliases != NULL) {
160		aliases_size = 0;
161		for (alias = ne->n_aliases; *alias; ++alias) {
162			desired_size += strlen(*alias) + 1;
163			++aliases_size;
164		}
165
166		desired_size += _ALIGNBYTES +
167		    (aliases_size + 1) * sizeof(char *);
168	}
169
170	if (*buffer_size < desired_size) {
171		/* this assignment is here for future use */
172		*buffer_size = desired_size;
173		return (NS_RETURN);
174	}
175
176	memcpy(&new_ne, ne, sizeof(struct netent));
177
178	*buffer_size = desired_size;
179	memset(buffer, 0, desired_size);
180	p = buffer + sizeof(struct netent) + sizeof(char *);
181	memcpy(buffer + sizeof(struct netent), &p, sizeof(char *));
182	p = (char *)_ALIGN(p);
183
184	if (new_ne.n_name != NULL) {
185		size = strlen(new_ne.n_name);
186		memcpy(p, new_ne.n_name, size);
187		new_ne.n_name = p;
188		p += size + 1;
189	}
190
191	if (new_ne.n_aliases != NULL) {
192		p = (char *)_ALIGN(p);
193		memcpy(p, new_ne.n_aliases, sizeof(char *) * aliases_size);
194		new_ne.n_aliases = (char **)p;
195		p += sizeof(char *) * (aliases_size + 1);
196
197		for (alias = new_ne.n_aliases; *alias; ++alias) {
198			size = strlen(*alias);
199			memcpy(p, *alias, size);
200			*alias = p;
201			p += size + 1;
202		}
203	}
204
205	memcpy(buffer, &new_ne, sizeof(struct netent));
206	return (NS_SUCCESS);
207}
208
209static int
210net_unmarshal_func(char *buffer, size_t buffer_size, void *retval, va_list ap,
211    void *cache_mdata)
212{
213	char *name;
214	uint32_t net;
215	int type;
216	struct netent *ne;
217	char *orig_buf;
218	size_t orig_buf_size;
219	int *ret_errno;
220
221	char *p;
222	char **alias;
223
224	switch ((enum nss_lookup_type)(uintptr_t)cache_mdata) {
225	case nss_lt_name:
226		name = va_arg(ap, char *);
227		break;
228	case nss_lt_id:
229		net = va_arg(ap, uint32_t);
230		type = va_arg(ap, int);
231		break;
232	case nss_lt_all:
233		break;
234	default:
235		/* should be unreachable */
236		return (NS_UNAVAIL);
237	}
238
239	ne = va_arg(ap, struct netent *);
240	orig_buf = va_arg(ap, char *);
241	orig_buf_size = va_arg(ap, size_t);
242	ret_errno = va_arg(ap, int *);
243
244	if (orig_buf_size <
245	    buffer_size - sizeof(struct netent) - sizeof(char *)) {
246		*ret_errno = ERANGE;
247		return (NS_RETURN);
248	}
249
250	memcpy(ne, buffer, sizeof(struct netent));
251	memcpy(&p, buffer + sizeof(struct netent), sizeof(char *));
252
253	orig_buf = (char *)_ALIGN(orig_buf);
254	memcpy(orig_buf, buffer + sizeof(struct netent) + sizeof(char *) +
255	    _ALIGN(p) - (size_t)p,
256	    buffer_size - sizeof(struct netent) - sizeof(char *) -
257	    _ALIGN(p) + (size_t)p);
258	p = (char *)_ALIGN(p);
259
260	NS_APPLY_OFFSET(ne->n_name, orig_buf, p, char *);
261	if (ne->n_aliases != NULL) {
262		NS_APPLY_OFFSET(ne->n_aliases, orig_buf, p, char **);
263
264		for (alias = ne->n_aliases; *alias; ++alias)
265			NS_APPLY_OFFSET(*alias, orig_buf, p, char *);
266	}
267
268	if (retval != NULL)
269		*((struct netent **)retval) = ne;
270
271	return (NS_SUCCESS);
272}
273#endif /* NS_CACHING */
274
275static void
276netent_data_free(void *ptr)
277{
278	struct netent_data *ned = ptr;
279
280	if (ned == NULL)
281		return;
282	ned->stayopen = 0;
283	_endnethtent(ned);
284	free(ned);
285}
286
287static void
288netdata_free(void *ptr)
289{
290	free(ptr);
291}
292
293int
294__copy_netent(struct netent *ne, struct netent *nptr, char *buf, size_t buflen)
295{
296	char *cp;
297	int i, n;
298	int numptr, len;
299
300	/* Find out the amount of space required to store the answer. */
301	numptr = 1; /* NULL ptr */
302	len = (char *)ALIGN(buf) - buf;
303	for (i = 0; ne->n_aliases[i]; i++, numptr++) {
304		len += strlen(ne->n_aliases[i]) + 1;
305	}
306	len += strlen(ne->n_name) + 1;
307	len += numptr * sizeof(char*);
308
309	if (len > (int)buflen) {
310		errno = ERANGE;
311		return (-1);
312	}
313
314	/* copy net value and type */
315	nptr->n_addrtype = ne->n_addrtype;
316	nptr->n_net = ne->n_net;
317
318	cp = (char *)ALIGN(buf) + numptr * sizeof(char *);
319
320	/* copy official name */
321	n = strlen(ne->n_name) + 1;
322	strcpy(cp, ne->n_name);
323	nptr->n_name = cp;
324	cp += n;
325
326	/* copy aliases */
327	nptr->n_aliases = (char **)ALIGN(buf);
328	for (i = 0 ; ne->n_aliases[i]; i++) {
329		n = strlen(ne->n_aliases[i]) + 1;
330		strcpy(cp, ne->n_aliases[i]);
331		nptr->n_aliases[i] = cp;
332		cp += n;
333	}
334	nptr->n_aliases[i] = NULL;
335
336	return (0);
337}
338
339int
340getnetbyname_r(const char *name, struct netent *ne, char *buffer,
341    size_t buflen, struct netent **result, int *h_errorp)
342{
343#ifdef NS_CACHING
344	static const nss_cache_info cache_info =
345    		NS_COMMON_CACHE_INFO_INITIALIZER(
346		networks, (void *)nss_lt_name,
347		net_id_func, net_marshal_func, net_unmarshal_func);
348#endif
349	static const ns_dtab dtab[] = {
350		NS_FILES_CB(_ht_getnetbyname, NULL)
351		{ NSSRC_DNS, _dns_getnetbyname, NULL },
352		NS_NIS_CB(_nis_getnetbyname, NULL) /* force -DHESIOD */
353#ifdef NS_CACHING
354		NS_CACHE_CB(&cache_info)
355#endif
356		{ 0 }
357	};
358	int rval, ret_errno = 0;
359
360	rval = _nsdispatch((void *)result, dtab, NSDB_NETWORKS,
361	    "getnetbyname_r", default_src, name, ne, buffer, buflen,
362	    &ret_errno, h_errorp);
363
364	if (rval != NS_SUCCESS) {
365		errno = ret_errno;
366		return ((ret_errno != 0) ? ret_errno : -1);
367	}
368	return (0);
369}
370
371int
372getnetbyaddr_r(uint32_t addr, int af, struct netent *ne, char *buffer,
373    size_t buflen, struct netent **result, int *h_errorp)
374{
375#ifdef NS_CACHING
376	static const nss_cache_info cache_info =
377    		NS_COMMON_CACHE_INFO_INITIALIZER(
378		networks, (void *)nss_lt_id,
379		net_id_func, net_marshal_func, net_unmarshal_func);
380#endif
381	static const ns_dtab dtab[] = {
382		NS_FILES_CB(_ht_getnetbyaddr, NULL)
383		{ NSSRC_DNS, _dns_getnetbyaddr, NULL },
384		NS_NIS_CB(_nis_getnetbyaddr, NULL) /* force -DHESIOD */
385#ifdef NS_CACHING
386		NS_CACHE_CB(&cache_info)
387#endif
388		{ 0 }
389	};
390	int rval, ret_errno = 0;
391
392	rval = _nsdispatch((void *)result, dtab, NSDB_NETWORKS,
393	    "getnetbyaddr_r", default_src, addr, af, ne, buffer, buflen,
394	    &ret_errno, h_errorp);
395
396	if (rval != NS_SUCCESS) {
397		errno = ret_errno;
398		return ((ret_errno != 0) ? ret_errno : -1);
399	}
400	return (0);
401}
402
403struct netent *
404getnetbyname(const char *name)
405{
406	struct netdata *nd;
407	struct netent *rval;
408	int ret_h_errno;
409
410	if ((nd = __netdata_init()) == NULL)
411		return (NULL);
412	if (getnetbyname_r(name, &nd->net, nd->data, sizeof(nd->data), &rval,
413	    &ret_h_errno) != 0)
414		return (NULL);
415	return (rval);
416}
417
418struct netent *
419getnetbyaddr(uint32_t addr, int af)
420{
421	struct netdata *nd;
422	struct netent *rval;
423	int ret_h_errno;
424
425	if ((nd = __netdata_init()) == NULL)
426		return (NULL);
427	if (getnetbyaddr_r(addr, af, &nd->net, nd->data, sizeof(nd->data),
428	    &rval, &ret_h_errno) != 0)
429		return (NULL);
430	return (rval);
431}
432
433void
434setnetent(int stayopen)
435{
436	struct netent_data *ned;
437
438	if ((ned = __netent_data_init()) == NULL)
439		return;
440	_setnethtent(stayopen, ned);
441	_setnetdnsent(stayopen);
442}
443
444void
445endnetent(void)
446{
447	struct netent_data *ned;
448
449	if ((ned = __netent_data_init()) == NULL)
450		return;
451	_endnethtent(ned);
452	_endnetdnsent();
453}
454