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 source tree.
9 */
10 #include "libbb.h"
11 #include "inet_common.h"
12
13 #if 0
14 # define dbg(...) bb_error_msg(__VA_ARGS__)
15 #else
16 # define dbg(...) ((void)0)
17 #endif
18
INET_resolve(const char * name,struct sockaddr_in * s_in,int hostfirst)19 int FAST_FUNC INET_resolve(const char *name, struct sockaddr_in *s_in, int hostfirst)
20 {
21 struct hostent *hp;
22 #if ENABLE_FEATURE_ETC_NETWORKS
23 struct netent *np;
24 #endif
25
26 /* Grmpf. -FvK */
27 s_in->sin_family = AF_INET;
28 s_in->sin_port = 0;
29
30 /* Default is special, meaning 0.0.0.0. */
31 if (strcmp(name, "default") == 0) {
32 s_in->sin_addr.s_addr = INADDR_ANY;
33 return 1;
34 }
35 /* Look to see if it's a dotted quad. */
36 if (inet_aton(name, &s_in->sin_addr)) {
37 return 0;
38 }
39 /* If we expect this to be a hostname, try hostname database first */
40 if (hostfirst) {
41 dbg("gethostbyname(%s)", name);
42 hp = gethostbyname(name);
43 if (hp) {
44 memcpy(&s_in->sin_addr, hp->h_addr_list[0],
45 sizeof(struct in_addr));
46 return 0;
47 }
48 }
49 #if ENABLE_FEATURE_ETC_NETWORKS
50 /* Try the NETWORKS database to see if this is a known network. */
51 dbg("getnetbyname(%s)", name);
52 np = getnetbyname(name);
53 if (np) {
54 s_in->sin_addr.s_addr = htonl(np->n_net);
55 return 1;
56 }
57 #endif
58 if (hostfirst) {
59 /* Don't try again */
60 return -1;
61 }
62 #ifdef DEBUG
63 res_init();
64 _res.options |= RES_DEBUG;
65 #endif
66 dbg("gethostbyname(%s)", name);
67 hp = gethostbyname(name);
68 if (!hp) {
69 return -1;
70 }
71 memcpy(&s_in->sin_addr, hp->h_addr_list[0], sizeof(struct in_addr));
72 return 0;
73 }
74
75
76 /* numeric: & 0x8000: "default" instead of "*",
77 * & 0x4000: host instead of net,
78 * & 0x0fff: don't resolve
79 */
INET_rresolve(struct sockaddr_in * s_in,int numeric,uint32_t netmask)80 char* FAST_FUNC INET_rresolve(struct sockaddr_in *s_in, int numeric, uint32_t netmask)
81 {
82 /* addr-to-name cache */
83 struct addr {
84 struct addr *next;
85 uint32_t nip;
86 smallint is_host;
87 char name[1];
88 };
89 static struct addr *cache = NULL;
90
91 struct addr *pn;
92 char *name;
93 uint32_t nip;
94 smallint is_host;
95
96 if (s_in->sin_family != AF_INET) {
97 dbg("rresolve: unsupported address family %d!", s_in->sin_family);
98 errno = EAFNOSUPPORT;
99 return NULL;
100 }
101 nip = s_in->sin_addr.s_addr;
102 dbg("rresolve: %08x mask:%08x num:%08x", (unsigned)nip, netmask, numeric);
103 if (numeric & 0x0FFF)
104 return xmalloc_sockaddr2dotted_noport((void*)s_in);
105 if (nip == INADDR_ANY) {
106 if (numeric & 0x8000)
107 return xstrdup("default");
108 return xstrdup("*");
109 }
110
111 is_host = ((nip & (~netmask)) != 0 || (numeric & 0x4000));
112
113 pn = cache;
114 while (pn) {
115 if (pn->nip == nip && pn->is_host == is_host) {
116 dbg("rresolve: found %s %08x in cache",
117 (is_host ? "host" : "net"), (unsigned)nip);
118 return xstrdup(pn->name);
119 }
120 pn = pn->next;
121 }
122
123 name = NULL;
124 if (is_host) {
125 dbg("sockaddr2host_noport(%08x)", (unsigned)nip);
126 name = xmalloc_sockaddr2host_noport((void*)s_in);
127 }
128 #if ENABLE_FEATURE_ETC_NETWORKS
129 else {
130 struct netent *np;
131 dbg("getnetbyaddr(%08x)", (unsigned)ntohl(nip));
132 np = getnetbyaddr(ntohl(nip), AF_INET);
133 if (np)
134 name = xstrdup(np->n_name);
135 }
136 #endif
137 if (!name)
138 name = xmalloc_sockaddr2dotted_noport((void*)s_in);
139
140 pn = xmalloc(sizeof(*pn) + strlen(name)); /* no '+ 1', it's already accounted for */
141 pn->next = cache;
142 pn->nip = nip;
143 pn->is_host = is_host;
144 strcpy(pn->name, name);
145 cache = pn;
146
147 return name;
148 }
149
150 #if ENABLE_FEATURE_IPV6
151
INET6_resolve(const char * name,struct sockaddr_in6 * sin6)152 int FAST_FUNC INET6_resolve(const char *name, struct sockaddr_in6 *sin6)
153 {
154 struct addrinfo req, *ai = NULL;
155 int s;
156
157 memset(&req, 0, sizeof(req));
158 req.ai_family = AF_INET6;
159 s = getaddrinfo(name, NULL, &req, &ai);
160 if (s != 0) {
161 bb_error_msg("getaddrinfo: %s: %d", name, s);
162 return -1;
163 }
164 memcpy(sin6, ai->ai_addr, sizeof(*sin6));
165 freeaddrinfo(ai);
166 return 0;
167 }
168
169 #ifndef IN6_IS_ADDR_UNSPECIFIED
170 # define IN6_IS_ADDR_UNSPECIFIED(a) \
171 (((uint32_t *) (a))[0] == 0 && ((uint32_t *) (a))[1] == 0 && \
172 ((uint32_t *) (a))[2] == 0 && ((uint32_t *) (a))[3] == 0)
173 #endif
174
175
INET6_rresolve(struct sockaddr_in6 * sin6,int numeric)176 char* FAST_FUNC INET6_rresolve(struct sockaddr_in6 *sin6, int numeric)
177 {
178 if (sin6->sin6_family != AF_INET6) {
179 dbg("rresolve: unsupported address family %d!",
180 sin6->sin6_family);
181 errno = EAFNOSUPPORT;
182 return NULL;
183 }
184 if (numeric & 0x7FFF) {
185 return xmalloc_sockaddr2dotted_noport((void*)sin6);
186 }
187 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
188 if (numeric & 0x8000)
189 return xstrdup("default");
190 return xstrdup("*");
191 }
192
193 return xmalloc_sockaddr2host_noport((void*)sin6);
194 }
195
196 #endif /* CONFIG_FEATURE_IPV6 */
197