1/*
2 * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and 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_sysctl.c,v 1.14.12.7 2004/03/08 09:04:56 marka Exp $ */
19
20/*
21 * Obtain the list of network interfaces using sysctl.
22 * See TCP/IP Illustrated Volume 2, sections 19.8, 19.14,
23 * and 19.16.
24 */
25
26#include <sys/param.h>
27#include <sys/sysctl.h>
28
29#include <net/route.h>
30#include <net/if_dl.h>
31
32/* XXX what about Alpha? */
33#ifdef sgi
34#define ROUNDUP(a) ((a) > 0 ? \
35		(1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \
36		sizeof(__uint64_t))
37#else
38#define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \
39                    : sizeof(long))
40#endif
41
42#define IFITER_MAGIC		ISC_MAGIC('I', 'F', 'I', 'S')
43#define VALID_IFITER(t)		ISC_MAGIC_VALID(t, IFITER_MAGIC)
44
45struct isc_interfaceiter {
46	unsigned int		magic;		/* Magic number. */
47	isc_mem_t		*mctx;
48	void			*buf;		/* Buffer for sysctl data. */
49	unsigned int		bufsize;	/* Bytes allocated. */
50	unsigned int		bufused;	/* Bytes used. */
51	unsigned int		pos;		/* Current offset in
52						   sysctl data. */
53	isc_interface_t		current;	/* Current interface data. */
54	isc_result_t		result;		/* Last result code. */
55};
56
57static int mib[6] = {
58	CTL_NET,
59	PF_ROUTE,
60        0,
61	0, 			/* Any address family. */
62        NET_RT_IFLIST,
63	0 			/* Flags. */
64};
65
66isc_result_t
67isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
68	isc_interfaceiter_t *iter;
69	isc_result_t result;
70	size_t bufsize;
71	size_t bufused;
72	char strbuf[ISC_STRERRORSIZE];
73
74	REQUIRE(iterp != NULL);
75	REQUIRE(*iterp == NULL);
76
77	iter = isc_mem_get(mctx, sizeof(*iter));
78	if (iter == NULL)
79		return (ISC_R_NOMEMORY);
80
81	iter->mctx = mctx;
82	iter->buf = 0;
83
84	/*
85	 * Determine the amount of memory needed.
86	 */
87	bufsize = 0;
88	if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) {
89		isc__strerror(errno, strbuf, sizeof(strbuf));
90		UNEXPECTED_ERROR(__FILE__, __LINE__,
91				 isc_msgcat_get(isc_msgcat,
92						ISC_MSGSET_IFITERSYSCTL,
93						ISC_MSG_GETIFLISTSIZE,
94						"getting interface "
95						"list size: sysctl: %s"),
96				 strbuf);
97		result = ISC_R_UNEXPECTED;
98		goto failure;
99	}
100	iter->bufsize = bufsize;
101
102	iter->buf = isc_mem_get(iter->mctx, iter->bufsize);
103	if (iter->buf == NULL) {
104		result = ISC_R_NOMEMORY;
105		goto failure;
106	}
107
108	bufused = bufsize;
109	if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) {
110		isc__strerror(errno, strbuf, sizeof(strbuf));
111		UNEXPECTED_ERROR(__FILE__, __LINE__,
112				 isc_msgcat_get(isc_msgcat,
113						ISC_MSGSET_IFITERSYSCTL,
114						ISC_MSG_GETIFLIST,
115						"getting interface list: "
116						"sysctl: %s"),
117				 strbuf);
118		result = ISC_R_UNEXPECTED;
119		goto failure;
120	}
121	iter->bufused = bufused;
122	INSIST(iter->bufused <= iter->bufsize);
123
124	/*
125	 * A newly created iterator has an undefined position
126	 * until isc_interfaceiter_first() is called.
127	 */
128	iter->pos = (unsigned int) -1;
129	iter->result = ISC_R_FAILURE;
130
131	iter->magic = IFITER_MAGIC;
132	*iterp = iter;
133	return (ISC_R_SUCCESS);
134
135 failure:
136	if (iter->buf != NULL)
137		isc_mem_put(mctx, iter->buf, iter->bufsize);
138	isc_mem_put(mctx, iter, sizeof(*iter));
139	return (result);
140}
141
142/*
143 * Get information about the current interface to iter->current.
144 * If successful, return ISC_R_SUCCESS.
145 * If the interface has an unsupported address family,
146 * return ISC_R_IGNORE.  In case of other failure,
147 * return ISC_R_UNEXPECTED.
148 */
149
150static isc_result_t
151internal_current(isc_interfaceiter_t *iter) {
152	struct ifa_msghdr *ifam, *ifam_end;
153
154	REQUIRE(VALID_IFITER(iter));
155	REQUIRE (iter->pos < (unsigned int) iter->bufused);
156
157	ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
158	ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused);
159
160	if (ifam->ifam_type == RTM_IFINFO) {
161		struct if_msghdr *ifm = (struct if_msghdr *) ifam;
162		struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1);
163		unsigned int namelen;
164
165		memset(&iter->current, 0, sizeof(iter->current));
166
167		namelen = sdl->sdl_nlen;
168		if (namelen > sizeof(iter->current.name) - 1)
169			namelen = sizeof(iter->current.name) - 1;
170
171		memset(iter->current.name, 0, sizeof(iter->current.name));
172		memcpy(iter->current.name, sdl->sdl_data, namelen);
173
174		iter->current.flags = 0;
175
176		if ((ifam->ifam_flags & IFF_UP) != 0)
177			iter->current.flags |= INTERFACE_F_UP;
178
179		if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0)
180			iter->current.flags |= INTERFACE_F_POINTTOPOINT;
181
182		if ((ifam->ifam_flags & IFF_LOOPBACK) != 0)
183			iter->current.flags |= INTERFACE_F_LOOPBACK;
184
185		if ((ifam->ifam_flags & IFF_BROADCAST) != 0) {
186			iter->current.flags |= INTERFACE_F_BROADCAST;
187		}
188#ifdef IFF_MULTICAST
189		if ((ifam->ifam_flags & IFF_MULTICAST) != 0) {
190			iter->current.flags |= INTERFACE_F_MULTICAST;
191		}
192#endif
193
194		/*
195		 * This is not an interface address.
196		 * Force another iteration.
197		 */
198		return (ISC_R_IGNORE);
199	} else if (ifam->ifam_type == RTM_NEWADDR) {
200		int i;
201		int family;
202		struct sockaddr *mask_sa = NULL;
203		struct sockaddr *addr_sa = NULL;
204		struct sockaddr *dst_sa = NULL;
205
206		struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
207		family = sa->sa_family;
208
209		for (i = 0; i < RTAX_MAX; i++)
210		{
211			if ((ifam->ifam_addrs & (1 << i)) == 0)
212				continue;
213
214			INSIST(sa < (struct sockaddr *) ifam_end);
215
216			switch (i) {
217			case RTAX_NETMASK: /* Netmask */
218				mask_sa = sa;
219				break;
220			case RTAX_IFA: /* Interface address */
221				addr_sa = sa;
222				break;
223			case RTAX_BRD: /* Broadcast or destination address */
224				dst_sa = sa;
225				break;
226			}
227#ifdef ISC_PLATFORM_HAVESALEN
228			sa = (struct sockaddr *)((char*)(sa)
229					 + ROUNDUP(sa->sa_len));
230#else
231#ifdef sgi
232			/*
233			 * Do as the contributed SGI code does.
234			 */
235			sa = (struct sockaddr *)((char*)(sa)
236					 + ROUNDUP(_FAKE_SA_LEN_DST(sa)));
237#else
238			/* XXX untested. */
239			sa = (struct sockaddr *)((char*)(sa)
240					 + ROUNDUP(sizeof(struct sockaddr)));
241#endif
242#endif
243		}
244
245		if (addr_sa == NULL)
246			return (ISC_R_IGNORE);
247
248		family = addr_sa->sa_family;
249		if (family != AF_INET && family != AF_INET6)
250			return (ISC_R_IGNORE);
251
252		iter->current.af = family;
253
254		get_addr(family, &iter->current.address, addr_sa,
255			 iter->current.name);
256
257		if (mask_sa != NULL)
258			get_addr(family, &iter->current.netmask, mask_sa,
259				 iter->current.name);
260
261		if (dst_sa != NULL &&
262		    (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
263			get_addr(family, &iter->current.dstaddress, dst_sa,
264				 iter->current.name);
265
266		if (dst_sa != NULL &&
267		    (iter->current.flags & INTERFACE_F_BROADCAST) != 0)
268			get_addr(family, &iter->current.broadcast, dst_sa,
269				 iter->current.name);
270
271
272		return (ISC_R_SUCCESS);
273	} else {
274		printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
275				      ISC_MSG_UNEXPECTEDTYPE,
276				      "warning: unexpected interface list "
277				      "message type\n"));
278		return (ISC_R_IGNORE);
279	}
280}
281
282/*
283 * Step the iterator to the next interface.  Unlike
284 * isc_interfaceiter_next(), this may leave the iterator
285 * positioned on an interface that will ultimately
286 * be ignored.  Return ISC_R_NOMORE if there are no more
287 * interfaces, otherwise ISC_R_SUCCESS.
288 */
289static isc_result_t
290internal_next(isc_interfaceiter_t *iter) {
291	struct ifa_msghdr *ifam;
292	REQUIRE (iter->pos < (unsigned int) iter->bufused);
293
294	ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
295
296	iter->pos += ifam->ifam_msglen;
297
298	if (iter->pos >= iter->bufused)
299		return (ISC_R_NOMORE);
300
301	return (ISC_R_SUCCESS);
302}
303
304static void
305internal_destroy(isc_interfaceiter_t *iter) {
306	UNUSED(iter); /* Unused. */
307	/*
308	 * Do nothing.
309	 */
310}
311
312static
313void internal_first(isc_interfaceiter_t *iter) {
314	iter->pos = 0;
315}
316