interfaceiter.c revision 290001 
1/*
2 * Copyright (C) 2004, 2005, 2007, 2008  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003  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: interfaceiter.c,v 1.45 2008/12/01 03:51:47 marka Exp $ */
19
20/*! \file */
21
22#include <config.h>
23
24#include <sys/types.h>
25#include <sys/ioctl.h>
26#ifdef HAVE_SYS_SOCKIO_H
27#include <sys/sockio.h>		/* Required for ifiter_ioctl.c. */
28#endif
29
30#include <stdio.h>
31#include <stdlib.h>
32#include <unistd.h>
33#include <errno.h>
34
35#include <isc/interfaceiter.h>
36#include <isc/log.h>
37#include <isc/magic.h>
38#include <isc/mem.h>
39#include <isc/msgs.h>
40#include <isc/net.h>
41#include <isc/print.h>
42#include <isc/result.h>
43#include <isc/strerror.h>
44#include <isc/string.h>
45#include <isc/types.h>
46#include <isc/util.h>
47
48/* Must follow <isc/net.h>. */
49#ifdef HAVE_NET_IF6_H
50#include <net/if6.h>
51#endif
52#include <net/if.h>
53
54#ifdef HAVE_LINUX_IF_ADDR_H
55# include <linux/if_addr.h>
56#endif
57
58/* Common utility functions */
59
60/*%
61 * Extract the network address part from a "struct sockaddr".
62 * \brief
63 * The address family is given explicitly
64 * instead of using src->sa_family, because the latter does not work
65 * for copying a network mask obtained by SIOCGIFNETMASK (it does
66 * not have a valid address family).
67 */
68
69static void
70get_addr(unsigned int family, isc_netaddr_t *dst, struct sockaddr *src,
71	 char *ifname)
72{
73	struct sockaddr_in6 *sa6;
74
75#if !defined(ISC_PLATFORM_HAVEIFNAMETOINDEX) || \
76    !defined(ISC_PLATFORM_HAVESCOPEID)
77	UNUSED(ifname);
78#endif
79
80	/* clear any remaining value for safety */
81	memset(dst, 0, sizeof(*dst));
82
83	dst->family = family;
84	switch (family) {
85	case AF_INET:
86		memcpy(&dst->type.in,
87		       &((struct sockaddr_in *)(void *)src)->sin_addr,
88		       sizeof(struct in_addr));
89		break;
90	case AF_INET6:
91		sa6 = (struct sockaddr_in6 *)(void *)src;
92		memcpy(&dst->type.in6, &sa6->sin6_addr,
93		       sizeof(struct in6_addr));
94#ifdef ISC_PLATFORM_HAVESCOPEID
95		if (sa6->sin6_scope_id != 0)
96			isc_netaddr_setzone(dst, sa6->sin6_scope_id);
97		else {
98			/*
99			 * BSD variants embed scope zone IDs in the 128bit
100			 * address as a kernel internal form.  Unfortunately,
101			 * the embedded IDs are not hidden from applications
102			 * when getting access to them by sysctl or ioctl.
103			 * We convert the internal format to the pure address
104			 * part and the zone ID part.
105			 * Since multicast addresses should not appear here
106			 * and they cannot be distinguished from netmasks,
107			 * we only consider unicast link-local addresses.
108			 */
109			if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) {
110				isc_uint16_t zone16;
111
112				memcpy(&zone16, &sa6->sin6_addr.s6_addr[2],
113				       sizeof(zone16));
114				zone16 = ntohs(zone16);
115				if (zone16 != 0) {
116					/* the zone ID is embedded */
117					isc_netaddr_setzone(dst,
118							    (isc_uint32_t)zone16);
119					dst->type.in6.s6_addr[2] = 0;
120					dst->type.in6.s6_addr[3] = 0;
121#ifdef ISC_PLATFORM_HAVEIFNAMETOINDEX
122				} else if (ifname != NULL) {
123					unsigned int zone;
124
125					/*
126					 * sin6_scope_id is still not provided,
127					 * but the corresponding interface name
128					 * is know.  Use the interface ID as
129					 * the link ID.
130					 */
131					zone = if_nametoindex(ifname);
132					if (zone != 0) {
133						isc_netaddr_setzone(dst,
134								    (isc_uint32_t)zone);
135					}
136#endif
137				}
138			}
139		}
140#endif
141		break;
142	default:
143		INSIST(0);
144		break;
145	}
146}
147
148/*
149 * Include system-dependent code.
150 */
151
152#ifdef __linux
153#define ISC_IF_INET6_SZ \
154    sizeof("00000000000000000000000000000001 01 80 10 80 XXXXXXloXXXXXXXX\n")
155static isc_result_t linux_if_inet6_next(isc_interfaceiter_t *);
156static isc_result_t linux_if_inet6_current(isc_interfaceiter_t *);
157static void linux_if_inet6_first(isc_interfaceiter_t *iter);
158#endif
159
160#if HAVE_GETIFADDRS
161#include "ifiter_getifaddrs.c"
162#elif HAVE_IFLIST_SYSCTL
163#include "ifiter_sysctl.c"
164#else
165#include "ifiter_ioctl.c"
166#endif
167
168#ifdef __linux
169static void
170linux_if_inet6_first(isc_interfaceiter_t *iter) {
171	if (iter->proc != NULL) {
172		rewind(iter->proc);
173		(void)linux_if_inet6_next(iter);
174	} else
175		iter->valid = ISC_R_NOMORE;
176}
177
178static isc_result_t
179linux_if_inet6_next(isc_interfaceiter_t *iter) {
180	if (iter->proc != NULL &&
181	    fgets(iter->entry, sizeof(iter->entry), iter->proc) != NULL)
182		iter->valid = ISC_R_SUCCESS;
183	else
184		iter->valid = ISC_R_NOMORE;
185	return (iter->valid);
186}
187
188static isc_result_t
189linux_if_inet6_current(isc_interfaceiter_t *iter) {
190	char address[33];
191	char name[IF_NAMESIZE+1];
192	struct in6_addr addr6;
193	unsigned int ifindex;
194	int prefix, scope, flags;
195	int res;
196	unsigned int i;
197
198	if (iter->valid != ISC_R_SUCCESS)
199		return (iter->valid);
200	if (iter->proc == NULL) {
201		isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
202			      ISC_LOGMODULE_INTERFACE, ISC_LOG_ERROR,
203			      "/proc/net/if_inet6:iter->proc == NULL");
204		return (ISC_R_FAILURE);
205	}
206
207	res = sscanf(iter->entry, "%32[a-f0-9] %x %x %x %x %16s\n",
208		     address, &ifindex, &prefix, &scope, &flags, name);
209	if (res != 6) {
210		isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
211			      ISC_LOGMODULE_INTERFACE, ISC_LOG_ERROR,
212			      "/proc/net/if_inet6:sscanf() -> %d (expected 6)",
213			      res);
214		return (ISC_R_FAILURE);
215	}
216	if (strlen(address) != 32) {
217		isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
218			      ISC_LOGMODULE_INTERFACE, ISC_LOG_ERROR,
219			      "/proc/net/if_inet6:strlen(%s) != 32", address);
220		return (ISC_R_FAILURE);
221	}
222	/*
223	** Ignore DAD addresses --
224	** we can't bind to them until they are resolved
225	*/
226#ifdef IFA_F_TENTATIVE
227	if (flags & IFA_F_TENTATIVE)
228		return (ISC_R_IGNORE);
229#endif
230
231	for (i = 0; i < 16; i++) {
232		unsigned char byte;
233		static const char hex[] = "0123456789abcdef";
234		byte = ((strchr(hex, address[i * 2]) - hex) << 4) |
235		       (strchr(hex, address[i * 2 + 1]) - hex);
236		addr6.s6_addr[i] = byte;
237	}
238	iter->current.af = AF_INET6;
239	iter->current.flags = INTERFACE_F_UP;
240	isc_netaddr_fromin6(&iter->current.address, &addr6);
241	iter->current.ifindex = ifindex;
242	if (isc_netaddr_islinklocal(&iter->current.address)) {
243		isc_netaddr_setzone(&iter->current.address,
244				    (isc_uint32_t)ifindex);
245	}
246	for (i = 0; i < 16; i++) {
247		if (prefix > 8) {
248			addr6.s6_addr[i] = 0xff;
249			prefix -= 8;
250		} else {
251			addr6.s6_addr[i] = (0xff << (8 - prefix)) & 0xff;
252			prefix = 0;
253		}
254	}
255	isc_netaddr_fromin6(&iter->current.netmask, &addr6);
256	strncpy(iter->current.name, name, sizeof(iter->current.name));
257	return (ISC_R_SUCCESS);
258}
259#endif
260
261/*
262 * The remaining code is common to the sysctl and ioctl case.
263 */
264
265isc_result_t
266isc_interfaceiter_current(isc_interfaceiter_t *iter,
267			  isc_interface_t *ifdata)
268{
269	REQUIRE(iter->result == ISC_R_SUCCESS);
270	memcpy(ifdata, &iter->current, sizeof(*ifdata));
271	return (ISC_R_SUCCESS);
272}
273
274isc_result_t
275isc_interfaceiter_first(isc_interfaceiter_t *iter) {
276	isc_result_t result;
277
278	REQUIRE(VALID_IFITER(iter));
279
280	internal_first(iter);
281	for (;;) {
282		result = internal_current(iter);
283		if (result != ISC_R_IGNORE)
284			break;
285		result = internal_next(iter);
286		if (result != ISC_R_SUCCESS)
287			break;
288	}
289	iter->result = result;
290	return (result);
291}
292
293isc_result_t
294isc_interfaceiter_next(isc_interfaceiter_t *iter) {
295	isc_result_t result;
296
297	REQUIRE(VALID_IFITER(iter));
298	REQUIRE(iter->result == ISC_R_SUCCESS);
299
300	for (;;) {
301		result = internal_next(iter);
302		if (result != ISC_R_SUCCESS)
303			break;
304		result = internal_current(iter);
305		if (result != ISC_R_IGNORE)
306			break;
307	}
308	iter->result = result;
309	return (result);
310}
311
312void
313isc_interfaceiter_destroy(isc_interfaceiter_t **iterp)
314{
315	isc_interfaceiter_t *iter;
316	REQUIRE(iterp != NULL);
317	iter = *iterp;
318	REQUIRE(VALID_IFITER(iter));
319
320	internal_destroy(iter);
321	if (iter->buf != NULL)
322		isc_mem_put(iter->mctx, iter->buf, iter->bufsize);
323
324	iter->magic = 0;
325	isc_mem_put(iter->mctx, iter, sizeof(*iter));
326	*iterp = NULL;
327}
328