1/*
2 * Copyright (C) 2004, 2005, 2007-2009  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2003  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: ifiter_getifaddrs.c,v 1.13 2009/09/24 23:48:13 tbox Exp $ */
19
20/*! \file
21 * \brief
22 * Obtain the list of network interfaces using the getifaddrs(3) library.
23 */
24
25#include <ifaddrs.h>
26
27/*% Iterator Magic */
28#define IFITER_MAGIC		ISC_MAGIC('I', 'F', 'I', 'G')
29/*% Valid Iterator */
30#define VALID_IFITER(t)		ISC_MAGIC_VALID(t, IFITER_MAGIC)
31
32#ifdef __linux
33static isc_boolean_t seenv6 = ISC_FALSE;
34#endif
35
36/*% Iterator structure */
37struct isc_interfaceiter {
38	unsigned int		magic;		/*%< Magic number. */
39	isc_mem_t		*mctx;
40	void			*buf;		/*%< (unused) */
41	unsigned int		bufsize;	/*%< (always 0) */
42	struct ifaddrs		*ifaddrs;	/*%< List of ifaddrs */
43	struct ifaddrs		*pos;		/*%< Ptr to current ifaddr */
44	isc_interface_t		current;	/*%< Current interface data. */
45	isc_result_t		result;		/*%< Last result code. */
46#ifdef  __linux
47	FILE *                  proc;
48	char                    entry[ISC_IF_INET6_SZ];
49	isc_result_t            valid;
50#endif
51};
52
53isc_result_t
54isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
55	isc_interfaceiter_t *iter;
56	isc_result_t result;
57	char strbuf[ISC_STRERRORSIZE];
58
59	REQUIRE(mctx != NULL);
60	REQUIRE(iterp != NULL);
61	REQUIRE(*iterp == NULL);
62
63	iter = isc_mem_get(mctx, sizeof(*iter));
64	if (iter == NULL)
65		return (ISC_R_NOMEMORY);
66
67	iter->mctx = mctx;
68	iter->buf = NULL;
69	iter->bufsize = 0;
70	iter->ifaddrs = NULL;
71#ifdef __linux
72	/*
73	 * Only open "/proc/net/if_inet6" if we have never seen a IPv6
74	 * address returned by getifaddrs().
75	 */
76	if (!seenv6)
77		iter->proc = fopen("/proc/net/if_inet6", "r");
78	else
79		iter->proc = NULL;
80	iter->valid = ISC_R_FAILURE;
81#endif
82
83	if (getifaddrs(&iter->ifaddrs) < 0) {
84		isc__strerror(errno, strbuf, sizeof(strbuf));
85		UNEXPECTED_ERROR(__FILE__, __LINE__,
86				 isc_msgcat_get(isc_msgcat,
87						ISC_MSGSET_IFITERGETIFADDRS,
88						ISC_MSG_GETIFADDRS,
89						"getting interface "
90						"addresses: getifaddrs: %s"),
91				 strbuf);
92		result = ISC_R_UNEXPECTED;
93		goto failure;
94	}
95
96	/*
97	 * A newly created iterator has an undefined position
98	 * until isc_interfaceiter_first() is called.
99	 */
100	iter->pos = NULL;
101	iter->result = ISC_R_FAILURE;
102
103	iter->magic = IFITER_MAGIC;
104	*iterp = iter;
105	return (ISC_R_SUCCESS);
106
107 failure:
108#ifdef __linux
109	if (iter->proc != NULL)
110		fclose(iter->proc);
111#endif
112	if (iter->ifaddrs != NULL) /* just in case */
113		freeifaddrs(iter->ifaddrs);
114	isc_mem_put(mctx, iter, sizeof(*iter));
115	return (result);
116}
117
118/*
119 * Get information about the current interface to iter->current.
120 * If successful, return ISC_R_SUCCESS.
121 * If the interface has an unsupported address family,
122 * return ISC_R_IGNORE.
123 */
124
125static isc_result_t
126internal_current(isc_interfaceiter_t *iter) {
127	struct ifaddrs *ifa;
128	int family;
129	unsigned int namelen;
130
131	REQUIRE(VALID_IFITER(iter));
132
133	ifa = iter->pos;
134
135#ifdef __linux
136	if (iter->pos == NULL)
137		return (linux_if_inet6_current(iter));
138#endif
139
140	INSIST(ifa != NULL);
141	INSIST(ifa->ifa_name != NULL);
142
143	if (ifa->ifa_addr == NULL)
144		return (ISC_R_IGNORE);
145
146	family = ifa->ifa_addr->sa_family;
147	if (family != AF_INET && family != AF_INET6)
148		return (ISC_R_IGNORE);
149
150#ifdef __linux
151	if (family == AF_INET6)
152		seenv6 = ISC_TRUE;
153#endif
154
155	memset(&iter->current, 0, sizeof(iter->current));
156
157	namelen = strlen(ifa->ifa_name);
158	if (namelen > sizeof(iter->current.name) - 1)
159		namelen = sizeof(iter->current.name) - 1;
160
161	memset(iter->current.name, 0, sizeof(iter->current.name));
162	memcpy(iter->current.name, ifa->ifa_name, namelen);
163
164	iter->current.flags = 0;
165
166	if ((ifa->ifa_flags & IFF_UP) != 0)
167		iter->current.flags |= INTERFACE_F_UP;
168
169	if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
170		iter->current.flags |= INTERFACE_F_POINTTOPOINT;
171
172	if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
173		iter->current.flags |= INTERFACE_F_LOOPBACK;
174
175	iter->current.af = family;
176
177	get_addr(family, &iter->current.address, ifa->ifa_addr, ifa->ifa_name);
178
179	if (ifa->ifa_netmask != NULL)
180		get_addr(family, &iter->current.netmask, ifa->ifa_netmask,
181			 ifa->ifa_name);
182
183	if (ifa->ifa_dstaddr != NULL &&
184	    (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
185		get_addr(family, &iter->current.dstaddress, ifa->ifa_dstaddr,
186			 ifa->ifa_name);
187
188	return (ISC_R_SUCCESS);
189}
190
191/*
192 * Step the iterator to the next interface.  Unlike
193 * isc_interfaceiter_next(), this may leave the iterator
194 * positioned on an interface that will ultimately
195 * be ignored.  Return ISC_R_NOMORE if there are no more
196 * interfaces, otherwise ISC_R_SUCCESS.
197 */
198static isc_result_t
199internal_next(isc_interfaceiter_t *iter) {
200
201	if (iter->pos != NULL)
202		iter->pos = iter->pos->ifa_next;
203	if (iter->pos == NULL) {
204#ifdef __linux
205		if (!seenv6)
206			return (linux_if_inet6_next(iter));
207#endif
208		return (ISC_R_NOMORE);
209	}
210
211	return (ISC_R_SUCCESS);
212}
213
214static void
215internal_destroy(isc_interfaceiter_t *iter) {
216
217#ifdef __linux
218	if (iter->proc != NULL)
219		fclose(iter->proc);
220	iter->proc = NULL;
221#endif
222	if (iter->ifaddrs)
223		freeifaddrs(iter->ifaddrs);
224	iter->ifaddrs = NULL;
225}
226
227static
228void internal_first(isc_interfaceiter_t *iter) {
229
230#ifdef __linux
231	linux_if_inet6_first(iter);
232#endif
233	iter->pos = iter->ifaddrs;
234}
235