summaryrefslogtreecommitdiff
path: root/libbb/inet_common.c
blob: d9e54514852eab2264d08c17ccbe1f09907fd6de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/*
 * stolen from net-tools-1.59 and stripped down for busybox by
 *                      Erik Andersen <andersen@codepoet.org>
 *
 * Heavily modified by Manuel Novoa III       Mar 12, 2001
 *
 * Version:     $Id: inet_common.c,v 1.8 2004/03/10 07:42:38 mjn3 Exp $
 *
 */

#include "libbb.h"
#include "inet_common.h"
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#ifdef DEBUG
# include <resolv.h>
#endif


const char bb_INET_default[] = "default";

int INET_resolve(const char *name, struct sockaddr_in *s_in, int hostfirst)
{
	struct hostent *hp;
	struct netent *np;

	/* Grmpf. -FvK */
	s_in->sin_family = AF_INET;
	s_in->sin_port = 0;

	/* Default is special, meaning 0.0.0.0. */
	if (!strcmp(name, bb_INET_default)) {
		s_in->sin_addr.s_addr = INADDR_ANY;
		return (1);
	}
	/* Look to see if it's a dotted quad. */
	if (inet_aton(name, &s_in->sin_addr)) {
		return 0;
	}
	/* If we expect this to be a hostname, try hostname database first */
#ifdef DEBUG
	if (hostfirst) {
		bb_error_msg("gethostbyname (%s)", name);
	}
#endif
	if (hostfirst && (hp = gethostbyname(name)) != (struct hostent *) NULL) {
		memcpy((char *) &s_in->sin_addr, (char *) hp->h_addr_list[0],
			   sizeof(struct in_addr));
		return 0;
	}
	/* Try the NETWORKS database to see if this is a known network. */
#ifdef DEBUG
	bb_error_msg("getnetbyname (%s)", name);
#endif
	if ((np = getnetbyname(name)) != (struct netent *) NULL) {
		s_in->sin_addr.s_addr = htonl(np->n_net);
		return 1;
	}
	if (hostfirst) {
		/* Don't try again */
		return -1;
	}
#ifdef DEBUG
	res_init();
	_res.options |= RES_DEBUG;
#endif

#ifdef DEBUG
	bb_error_msg("gethostbyname (%s)", name);
#endif
	if ((hp = gethostbyname(name)) == (struct hostent *) NULL) {
		return -1;
	}
	memcpy((char *) &s_in->sin_addr, (char *) hp->h_addr_list[0],
		   sizeof(struct in_addr));

	return 0;
}

/* cache */
struct addr {
	struct sockaddr_in addr;
	char *name;
	int host;
	struct addr *next;
};

static struct addr *INET_nn = NULL;	/* addr-to-name cache           */

/* numeric: & 0x8000: default instead of *,
 *          & 0x4000: host instead of net,
 *          & 0x0fff: don't resolve
 */
int INET_rresolve(char *name, size_t len, struct sockaddr_in *s_in,
				  int numeric, unsigned int netmask)
{
	struct hostent *ent;
	struct netent *np;
	struct addr *pn;
	unsigned long ad, host_ad;
	int host = 0;

	/* Grmpf. -FvK */
	if (s_in->sin_family != AF_INET) {
#ifdef DEBUG
		bb_error_msg("rresolve: unsupport address family %d !",
				  s_in->sin_family);
#endif
		errno = EAFNOSUPPORT;
		return (-1);
	}
	ad = (unsigned long) s_in->sin_addr.s_addr;
#ifdef DEBUG
	bb_error_msg("rresolve: %08lx, mask %08x, num %08x", ad, netmask, numeric);
#endif
	if (ad == INADDR_ANY) {
		if ((numeric & 0x0FFF) == 0) {
			if (numeric & 0x8000)
				safe_strncpy(name, bb_INET_default, len);
			else
				safe_strncpy(name, "*", len);
			return (0);
		}
	}
	if (numeric & 0x0FFF) {
		safe_strncpy(name, inet_ntoa(s_in->sin_addr), len);
		return (0);
	}

	if ((ad & (~netmask)) != 0 || (numeric & 0x4000))
		host = 1;
	pn = INET_nn;
	while (pn != NULL) {
		if (pn->addr.sin_addr.s_addr == ad && pn->host == host) {
			safe_strncpy(name, pn->name, len);
#ifdef DEBUG
			bb_error_msg("rresolve: found %s %08lx in cache",
					  (host ? "host" : "net"), ad);
#endif
			return (0);
		}
		pn = pn->next;
	}

	host_ad = ntohl(ad);
	np = NULL;
	ent = NULL;
	if (host) {
#ifdef DEBUG
		bb_error_msg("gethostbyaddr (%08lx)", ad);
#endif
		ent = gethostbyaddr((char *) &ad, 4, AF_INET);
		if (ent != NULL) {
			safe_strncpy(name, ent->h_name, len);
		}
	} else {
#ifdef DEBUG
		bb_error_msg("getnetbyaddr (%08lx)", host_ad);
#endif
		np = getnetbyaddr(host_ad, AF_INET);
		if (np != NULL) {
			safe_strncpy(name, np->n_name, len);
		}
	}
	if ((ent == NULL) && (np == NULL)) {
		safe_strncpy(name, inet_ntoa(s_in->sin_addr), len);
	}
	pn = (struct addr *) xmalloc(sizeof(struct addr));
	pn->addr = *s_in;
	pn->next = INET_nn;
	pn->host = host;
	pn->name = bb_xstrdup(name);
	INET_nn = pn;

	return (0);
}

#ifdef CONFIG_FEATURE_IPV6

int INET6_resolve(const char *name, struct sockaddr_in6 *sin6)
{
	struct addrinfo req, *ai;
	int s;

	memset(&req, '\0', sizeof req);
	req.ai_family = AF_INET6;
	if ((s = getaddrinfo(name, NULL, &req, &ai))) {
		bb_error_msg("getaddrinfo: %s: %d", name, s);
		return -1;
	}
	memcpy(sin6, ai->ai_addr, sizeof(struct sockaddr_in6));

	freeaddrinfo(ai);

	return (0);
}

#ifndef IN6_IS_ADDR_UNSPECIFIED
# define IN6_IS_ADDR_UNSPECIFIED(a) \
	(((uint32_t *) (a))[0] == 0 && ((uint32_t *) (a))[1] == 0 && \
	 ((uint32_t *) (a))[2] == 0 && ((uint32_t *) (a))[3] == 0)
#endif


int INET6_rresolve(char *name, size_t len, struct sockaddr_in6 *sin6,
				   int numeric)
{
	int s;

	/* Grmpf. -FvK */
	if (sin6->sin6_family != AF_INET6) {
#ifdef DEBUG
		bb_error_msg(_("rresolve: unsupport address family %d !\n"),
				  sin6->sin6_family);
#endif
		errno = EAFNOSUPPORT;
		return (-1);
	}
	if (numeric & 0x7FFF) {
		inet_ntop(AF_INET6, &sin6->sin6_addr, name, len);
		return (0);
	}
	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
		if (numeric & 0x8000) {
			strcpy(name, "default");
		} else {
			strcpy(name, "*");
		}
		return (0);
	}

	s = getnameinfo((struct sockaddr *) sin6, sizeof(struct sockaddr_in6), name, len, NULL, 0, 0);
	if (s) {
		bb_error_msg("getnameinfo failed");
		return -1;
	}
	return (0);
}

#endif							/* CONFIG_FEATURE_IPV6 */