1/*
2   Unix SMB/CIFS implementation.
3   return a list of network interfaces
4   Copyright (C) Andrew Tridgell 1998
5   Copyright (C) Jeremy Allison 2007
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "includes.h"
22
23/****************************************************************************
24 Create a struct sockaddr_storage with the netmask bits set to 1.
25****************************************************************************/
26
27bool make_netmask(struct sockaddr_storage *pss_out,
28			const struct sockaddr_storage *pss_in,
29			unsigned long masklen)
30{
31	*pss_out = *pss_in;
32	/* Now apply masklen bits of mask. */
33#if defined(HAVE_IPV6)
34	if (pss_in->ss_family == AF_INET6) {
35		char *p = (char *)&((struct sockaddr_in6 *)pss_out)->sin6_addr;
36		unsigned int i;
37
38		if (masklen > 128) {
39			return false;
40		}
41		for (i = 0; masklen >= 8; masklen -= 8, i++) {
42			*p++ = 0xff;
43		}
44		/* Deal with the partial byte. */
45		*p++ &= (0xff & ~(0xff>>masklen));
46		i++;
47		for (;i < sizeof(struct in6_addr); i++) {
48			*p++ = '\0';
49		}
50		return true;
51	}
52#endif
53	if (pss_in->ss_family == AF_INET) {
54		if (masklen > 32) {
55			return false;
56		}
57		((struct sockaddr_in *)pss_out)->sin_addr.s_addr =
58			htonl(((0xFFFFFFFFL >> masklen) ^ 0xFFFFFFFFL));
59		return true;
60	}
61	return false;
62}
63
64/****************************************************************************
65 Create a struct sockaddr_storage set to the broadcast or network adress from
66 an incoming sockaddr_storage.
67****************************************************************************/
68
69static void make_bcast_or_net(struct sockaddr_storage *pss_out,
70			const struct sockaddr_storage *pss_in,
71			const struct sockaddr_storage *nmask,
72			bool make_bcast_p)
73{
74	unsigned int i = 0, len = 0;
75	char *pmask = NULL;
76	char *p = NULL;
77	*pss_out = *pss_in;
78
79	/* Set all zero netmask bits to 1. */
80#if defined(HAVE_IPV6)
81	if (pss_in->ss_family == AF_INET6) {
82		p = (char *)&((struct sockaddr_in6 *)pss_out)->sin6_addr;
83		pmask = (char *)&((struct sockaddr_in6 *)nmask)->sin6_addr;
84		len = 16;
85	}
86#endif
87	if (pss_in->ss_family == AF_INET) {
88		p = (char *)&((struct sockaddr_in *)pss_out)->sin_addr;
89		pmask = (char *)&((struct sockaddr_in *)nmask)->sin_addr;
90		len = 4;
91	}
92
93	for (i = 0; i < len; i++, p++, pmask++) {
94		if (make_bcast_p) {
95			*p = (*p & *pmask) | (*pmask ^ 0xff);
96		} else {
97			/* make_net */
98			*p = (*p & *pmask);
99		}
100	}
101}
102
103void make_bcast(struct sockaddr_storage *pss_out,
104			const struct sockaddr_storage *pss_in,
105			const struct sockaddr_storage *nmask)
106{
107	make_bcast_or_net(pss_out, pss_in, nmask, true);
108}
109
110void make_net(struct sockaddr_storage *pss_out,
111			const struct sockaddr_storage *pss_in,
112			const struct sockaddr_storage *nmask)
113{
114	make_bcast_or_net(pss_out, pss_in, nmask, false);
115}
116
117/****************************************************************************
118 Try the "standard" getifaddrs/freeifaddrs interfaces.
119 Also gets IPv6 interfaces.
120****************************************************************************/
121
122/****************************************************************************
123 Get the netmask address for a local interface.
124****************************************************************************/
125
126static int _get_interfaces(TALLOC_CTX *mem_ctx, struct iface_struct **pifaces)
127{
128	struct iface_struct *ifaces;
129	struct ifaddrs *iflist = NULL;
130	struct ifaddrs *ifptr = NULL;
131	int count;
132	int total = 0;
133	size_t copy_size;
134#ifndef HAVE_GETIFADDRS
135	if (getifaddrs_local(&iflist) < 0) {
136#else
137	if (getifaddrs(&iflist) < 0) {
138#endif
139		return -1;
140	}
141
142	count = 0;
143	for (ifptr = iflist; ifptr != NULL; ifptr = ifptr->ifa_next) {
144		if (!ifptr->ifa_addr || !ifptr->ifa_netmask) {
145			continue;
146		}
147		if (!(ifptr->ifa_flags & IFF_UP)) {
148			continue;
149		}
150		count += 1;
151	}
152
153	ifaces = talloc_array(mem_ctx, struct iface_struct, count);
154	if (ifaces == NULL) {
155		errno = ENOMEM;
156		return -1;
157	}
158
159	/* Loop through interfaces, looking for given IP address */
160	for (ifptr = iflist; ifptr != NULL; ifptr = ifptr->ifa_next) {
161
162		if (!ifptr->ifa_addr || !ifptr->ifa_netmask) {
163			continue;
164		}
165
166		/* Check the interface is up. */
167		if (!(ifptr->ifa_flags & IFF_UP)) {
168			continue;
169		}
170
171		memset(&ifaces[total], '\0', sizeof(ifaces[total]));
172
173		copy_size = sizeof(struct sockaddr_in);
174
175		ifaces[total].flags = ifptr->ifa_flags;
176
177#if defined(HAVE_IPV6)
178		if (ifptr->ifa_addr->sa_family == AF_INET6) {
179			copy_size = sizeof(struct sockaddr_in6);
180		}
181#endif
182
183		memcpy(&ifaces[total].ip, ifptr->ifa_addr, copy_size);
184		memcpy(&ifaces[total].netmask, ifptr->ifa_netmask, copy_size);
185
186		if (ifaces[total].flags & (IFF_BROADCAST|IFF_LOOPBACK)) {
187			make_bcast(&ifaces[total].bcast,
188				&ifaces[total].ip,
189				&ifaces[total].netmask);
190		} else if ((ifaces[total].flags & IFF_POINTOPOINT) &&
191			       ifptr->ifa_dstaddr ) {
192			memcpy(&ifaces[total].bcast,
193				ifptr->ifa_dstaddr,
194				copy_size);
195		} else {
196			continue;
197		}
198
199		strlcpy(ifaces[total].name, ifptr->ifa_name,
200			sizeof(ifaces[total].name));
201		total++;
202	}
203#ifndef HAVE_GETIFADDRS
204	freeifaddrs_local(iflist);
205#else
206	freeifaddrs(iflist);
207#endif
208
209	*pifaces = ifaces;
210	return total;
211}
212
213static int iface_comp(struct iface_struct *i1, struct iface_struct *i2)
214{
215	int r;
216
217#if defined(HAVE_IPV6)
218	/*
219	 * If we have IPv6 - sort these interfaces lower
220	 * than any IPv4 ones.
221	 */
222	if (i1->ip.ss_family == AF_INET6 &&
223			i2->ip.ss_family == AF_INET) {
224		return -1;
225	} else if (i1->ip.ss_family == AF_INET &&
226			i2->ip.ss_family == AF_INET6) {
227		return 1;
228	}
229
230	if (i1->ip.ss_family == AF_INET6) {
231		struct sockaddr_in6 *s1 = (struct sockaddr_in6 *)&i1->ip;
232		struct sockaddr_in6 *s2 = (struct sockaddr_in6 *)&i2->ip;
233
234		r = memcmp(&s1->sin6_addr,
235				&s2->sin6_addr,
236				sizeof(struct in6_addr));
237		if (r) {
238			return r;
239		}
240
241		s1 = (struct sockaddr_in6 *)&i1->netmask;
242		s2 = (struct sockaddr_in6 *)&i2->netmask;
243
244		r = memcmp(&s1->sin6_addr,
245				&s2->sin6_addr,
246				sizeof(struct in6_addr));
247		if (r) {
248			return r;
249		}
250	}
251#endif
252
253	/* AIX uses __ss_family instead of ss_family inside of
254	   sockaddr_storage. Instead of trying to figure out which field to
255	   use, we can just cast it to a sockaddr.
256	 */
257
258	if (((struct sockaddr *)&i1->ip)->sa_family == AF_INET) {
259		struct sockaddr_in *s1 = (struct sockaddr_in *)&i1->ip;
260		struct sockaddr_in *s2 = (struct sockaddr_in *)&i2->ip;
261
262		r = ntohl(s1->sin_addr.s_addr) -
263			ntohl(s2->sin_addr.s_addr);
264		if (r) {
265			return r;
266		}
267
268		s1 = (struct sockaddr_in *)&i1->netmask;
269		s2 = (struct sockaddr_in *)&i2->netmask;
270
271		return ntohl(s1->sin_addr.s_addr) -
272			ntohl(s2->sin_addr.s_addr);
273	}
274	return 0;
275}
276
277/* this wrapper is used to remove duplicates from the interface list generated
278   above */
279int get_interfaces(TALLOC_CTX *mem_ctx, struct iface_struct **pifaces)
280{
281	struct iface_struct *ifaces;
282	int total, i, j;
283
284	total = _get_interfaces(mem_ctx, &ifaces);
285	if (total <= 0) return total;
286
287	/* now we need to remove duplicates */
288	qsort(ifaces, total, sizeof(ifaces[0]), QSORT_CAST iface_comp);
289
290	for (i=1;i<total;) {
291		if (iface_comp(&ifaces[i-1], &ifaces[i]) == 0) {
292			for (j=i-1;j<total-1;j++) {
293				ifaces[j] = ifaces[j+1];
294			}
295			total--;
296		} else {
297			i++;
298		}
299	}
300
301	*pifaces = ifaces;
302	return total;
303}
304
305