1/* vi: set sw=4 ts=4: */
2/*
3 * stolen from net-tools-1.59 and stripped down for busybox by
4 *                      Erik Andersen <andersen@codepoet.org>
5 *
6 * Heavily modified by Manuel Novoa III       Mar 12, 2001
7 *
8 * Licensed under GPLv2, see file LICENSE in this tarball for details.
9 */
10
11#include "libbb.h"
12#include "inet_common.h"
13
14int FAST_FUNC INET_resolve(const char *name, struct sockaddr_in *s_in, int hostfirst)
15{
16	struct hostent *hp;
17#if ENABLE_FEATURE_ETC_NETWORKS
18	struct netent *np;
19#endif
20
21	/* Grmpf. -FvK */
22	s_in->sin_family = AF_INET;
23	s_in->sin_port = 0;
24
25	/* Default is special, meaning 0.0.0.0. */
26	if (!strcmp(name, bb_str_default)) {
27		s_in->sin_addr.s_addr = INADDR_ANY;
28		return 1;
29	}
30	/* Look to see if it's a dotted quad. */
31	if (inet_aton(name, &s_in->sin_addr)) {
32		return 0;
33	}
34	/* If we expect this to be a hostname, try hostname database first */
35#ifdef DEBUG
36	if (hostfirst) {
37		bb_error_msg("gethostbyname(%s)", name);
38	}
39#endif
40	if (hostfirst) {
41		hp = gethostbyname(name);
42		if (hp != NULL) {
43			memcpy(&s_in->sin_addr, hp->h_addr_list[0],
44				sizeof(struct in_addr));
45			return 0;
46		}
47	}
48#if ENABLE_FEATURE_ETC_NETWORKS
49	/* Try the NETWORKS database to see if this is a known network. */
50#ifdef DEBUG
51	bb_error_msg("getnetbyname(%s)", name);
52#endif
53	np = getnetbyname(name);
54	if (np != NULL) {
55		s_in->sin_addr.s_addr = htonl(np->n_net);
56		return 1;
57	}
58#endif
59	if (hostfirst) {
60		/* Don't try again */
61		return -1;
62	}
63#ifdef DEBUG
64	res_init();
65	_res.options |= RES_DEBUG;
66	bb_error_msg("gethostbyname(%s)", name);
67#endif
68	hp = gethostbyname(name);
69	if (hp == NULL) {
70		return -1;
71	}
72	memcpy(&s_in->sin_addr, hp->h_addr_list[0], sizeof(struct in_addr));
73	return 0;
74}
75
76
77/* numeric: & 0x8000: default instead of *,
78 *          & 0x4000: host instead of net,
79 *          & 0x0fff: don't resolve
80 */
81char* FAST_FUNC INET_rresolve(struct sockaddr_in *s_in, int numeric, uint32_t netmask)
82{
83	/* addr-to-name cache */
84	struct addr {
85		struct addr *next;
86		struct sockaddr_in addr;
87		int host;
88		char name[1];
89	};
90	static struct addr *cache = NULL;
91
92	struct addr *pn;
93	char *name;
94	uint32_t ad, host_ad;
95	int host = 0;
96
97	if (s_in->sin_family != AF_INET) {
98#ifdef DEBUG
99		bb_error_msg("rresolve: unsupported address family %d!",
100				  s_in->sin_family);
101#endif
102		errno = EAFNOSUPPORT;
103		return NULL;
104	}
105	ad = s_in->sin_addr.s_addr;
106#ifdef DEBUG
107	bb_error_msg("rresolve: %08x, mask %08x, num %08x", (unsigned)ad, netmask, numeric);
108#endif
109	if (ad == INADDR_ANY) {
110		if ((numeric & 0x0FFF) == 0) {
111			if (numeric & 0x8000)
112				return xstrdup(bb_str_default);
113			return xstrdup("*");
114		}
115	}
116	if (numeric & 0x0FFF)
117		return xstrdup(inet_ntoa(s_in->sin_addr));
118
119	if ((ad & (~netmask)) != 0 || (numeric & 0x4000))
120		host = 1;
121	pn = cache;
122	while (pn) {
123		if (pn->addr.sin_addr.s_addr == ad && pn->host == host) {
124#ifdef DEBUG
125			bb_error_msg("rresolve: found %s %08x in cache",
126					  (host ? "host" : "net"), (unsigned)ad);
127#endif
128			return xstrdup(pn->name);
129		}
130		pn = pn->next;
131	}
132
133	host_ad = ntohl(ad);
134	name = NULL;
135	if (host) {
136		struct hostent *ent;
137#ifdef DEBUG
138		bb_error_msg("gethostbyaddr (%08x)", (unsigned)ad);
139#endif
140		ent = gethostbyaddr((char *) &ad, 4, AF_INET);
141		if (ent)
142			name = xstrdup(ent->h_name);
143	} else if (ENABLE_FEATURE_ETC_NETWORKS) {
144		struct netent *np;
145#ifdef DEBUG
146		bb_error_msg("getnetbyaddr (%08x)", (unsigned)host_ad);
147#endif
148		np = getnetbyaddr(host_ad, AF_INET);
149		if (np)
150			name = xstrdup(np->n_name);
151	}
152	if (!name)
153		name = xstrdup(inet_ntoa(s_in->sin_addr));
154	pn = xmalloc(sizeof(*pn) + strlen(name)); /* no '+ 1', it's already accounted for */
155	pn->next = cache;
156	pn->addr = *s_in;
157	pn->host = host;
158	strcpy(pn->name, name);
159	cache = pn;
160	return name;
161}
162
163#if ENABLE_FEATURE_IPV6
164
165int FAST_FUNC INET6_resolve(const char *name, struct sockaddr_in6 *sin6)
166{
167	struct addrinfo req, *ai = NULL;
168	int s;
169
170	memset(&req, 0, sizeof(req));
171	req.ai_family = AF_INET6;
172	s = getaddrinfo(name, NULL, &req, &ai);
173	if (s != 0) {
174		bb_error_msg("getaddrinfo: %s: %d", name, s);
175		return -1;
176	}
177	memcpy(sin6, ai->ai_addr, sizeof(*sin6));
178	freeaddrinfo(ai);
179	return 0;
180}
181
182#ifndef IN6_IS_ADDR_UNSPECIFIED
183# define IN6_IS_ADDR_UNSPECIFIED(a) \
184	(((uint32_t *) (a))[0] == 0 && ((uint32_t *) (a))[1] == 0 && \
185	 ((uint32_t *) (a))[2] == 0 && ((uint32_t *) (a))[3] == 0)
186#endif
187
188
189char* FAST_FUNC INET6_rresolve(struct sockaddr_in6 *sin6, int numeric)
190{
191	char name[128];
192	int s;
193
194	if (sin6->sin6_family != AF_INET6) {
195#ifdef DEBUG
196		bb_error_msg("rresolve: unsupported address family %d!",
197				  sin6->sin6_family);
198#endif
199		errno = EAFNOSUPPORT;
200		return NULL;
201	}
202	if (numeric & 0x7FFF) {
203		inet_ntop(AF_INET6, &sin6->sin6_addr, name, sizeof(name));
204		return xstrdup(name);
205	}
206	if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
207		if (numeric & 0x8000)
208			return xstrdup(bb_str_default);
209		return xstrdup("*");
210	}
211
212	s = getnameinfo((struct sockaddr *) sin6, sizeof(*sin6),
213				name, sizeof(name),
214				/*serv,servlen:*/ NULL, 0,
215				0);
216	if (s != 0) {
217		bb_error_msg("getnameinfo failed");
218		return NULL;
219	}
220	return xstrdup(name);
221}
222
223#endif		/* CONFIG_FEATURE_IPV6 */
224