1 /*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996,1999 by Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and 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
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #if !defined(LINT) && !defined(CODECENTER)
19 static const char rcsid[] = "$Id: getnetent.c,v 1.7 2005/04/27 04:56:25 sra Exp $";
20 #endif
21
22 /* Imports */
23
24 #include "port_before.h"
25
26 #if !defined(__BIND_NOSTATIC)
27
28 #include <sys/types.h>
29 #include <sys/socket.h>
30
31 #include <netinet/in.h>
32 #include <arpa/nameser.h>
33 #include <arpa/inet.h>
34
35 #include <ctype.h>
36 #include <errno.h>
37 #include <netdb.h>
38 #include <resolv.h>
39 #include <stdlib.h>
40 #include <string.h>
41
42 #include <irs.h>
43
44 #include "port_after.h"
45
46 #include "irs_p.h"
47 #include "irs_data.h"
48
49 /* Definitions */
50
51 struct pvt {
52 struct netent netent;
53 char * aliases[1];
54 char name[MAXDNAME + 1];
55 };
56
57 /* Forward */
58
59 static struct net_data *init(void);
60 static struct netent *nw_to_net(struct nwent *, struct net_data *);
61 static void freepvt(struct net_data *);
62 static struct netent *fakeaddr(const char *, int af, struct net_data *);
63
64 /* Portability */
65
66 #ifndef INADDR_NONE
67 # define INADDR_NONE 0xffffffff
68 #endif
69
70 /* Public */
71
72 struct netent *
getnetent()73 getnetent() {
74 struct net_data *net_data = init();
75
76 return (getnetent_p(net_data));
77 }
78
79 struct netent *
getnetbyname(const char * name)80 getnetbyname(const char *name) {
81 struct net_data *net_data = init();
82
83 return (getnetbyname_p(name, net_data));
84 }
85
86 struct netent *
getnetbyaddr(unsigned long net,int type)87 getnetbyaddr(unsigned long net, int type) {
88 struct net_data *net_data = init();
89
90 return (getnetbyaddr_p(net, type, net_data));
91 }
92
93 void
setnetent(int stayopen)94 setnetent(int stayopen) {
95 struct net_data *net_data = init();
96
97 setnetent_p(stayopen, net_data);
98 }
99
100
101 void
endnetent()102 endnetent() {
103 struct net_data *net_data = init();
104
105 endnetent_p(net_data);
106 }
107
108 /* Shared private. */
109
110 struct netent *
getnetent_p(struct net_data * net_data)111 getnetent_p(struct net_data *net_data) {
112 struct irs_nw *nw;
113
114 if (!net_data || !(nw = net_data->nw))
115 return (NULL);
116 net_data->nww_last = (*nw->next)(nw);
117 net_data->nw_last = nw_to_net(net_data->nww_last, net_data);
118 return (net_data->nw_last);
119 }
120
121 struct netent *
getnetbyname_p(const char * name,struct net_data * net_data)122 getnetbyname_p(const char *name, struct net_data *net_data) {
123 struct irs_nw *nw;
124 struct netent *np;
125 char **nap;
126
127 if (!net_data || !(nw = net_data->nw))
128 return (NULL);
129 if (net_data->nw_stayopen && net_data->nw_last) {
130 if (!strcmp(net_data->nw_last->n_name, name))
131 return (net_data->nw_last);
132 for (nap = net_data->nw_last->n_aliases; nap && *nap; nap++)
133 if (!strcmp(name, *nap))
134 return (net_data->nw_last);
135 }
136 if ((np = fakeaddr(name, AF_INET, net_data)) != NULL)
137 return (np);
138 net_data->nww_last = (*nw->byname)(nw, name, AF_INET);
139 net_data->nw_last = nw_to_net(net_data->nww_last, net_data);
140 if (!net_data->nw_stayopen)
141 endnetent();
142 return (net_data->nw_last);
143 }
144
145 struct netent *
getnetbyaddr_p(unsigned long net,int type,struct net_data * net_data)146 getnetbyaddr_p(unsigned long net, int type, struct net_data *net_data) {
147 struct irs_nw *nw;
148 u_char addr[4];
149 int bits;
150
151 if (!net_data || !(nw = net_data->nw))
152 return (NULL);
153 if (net_data->nw_stayopen && net_data->nw_last)
154 if (type == net_data->nw_last->n_addrtype &&
155 net == net_data->nw_last->n_net)
156 return (net_data->nw_last);
157
158 /* cannonize net(host order) */
159 if (net < 256UL) {
160 net <<= 24;
161 bits = 8;
162 } else if (net < 65536UL) {
163 net <<= 16;
164 bits = 16;
165 } else if (net < 16777216UL) {
166 net <<= 8;
167 bits = 24;
168 } else
169 bits = 32;
170
171 /* convert to net order */
172 addr[0] = (0xFF000000 & net) >> 24;
173 addr[1] = (0x00FF0000 & net) >> 16;
174 addr[2] = (0x0000FF00 & net) >> 8;
175 addr[3] = (0x000000FF & net);
176
177 /* reduce bits to as close to natural number as possible */
178 if ((bits == 32) && (addr[0] < 224) && (addr[3] == 0)) {
179 if ((addr[0] < 192) && (addr[2] == 0)) {
180 if ((addr[0] < 128) && (addr[1] == 0))
181 bits = 8;
182 else
183 bits = 16;
184 } else {
185 bits = 24;
186 }
187 }
188
189 net_data->nww_last = (*nw->byaddr)(nw, addr, bits, AF_INET);
190 net_data->nw_last = nw_to_net(net_data->nww_last, net_data);
191 if (!net_data->nw_stayopen)
192 endnetent();
193 return (net_data->nw_last);
194 }
195
196
197
198
199 void
setnetent_p(int stayopen,struct net_data * net_data)200 setnetent_p(int stayopen, struct net_data *net_data) {
201 struct irs_nw *nw;
202
203 if (!net_data || !(nw = net_data->nw))
204 return;
205 freepvt(net_data);
206 (*nw->rewind)(nw);
207 net_data->nw_stayopen = (stayopen != 0);
208 if (stayopen == 0)
209 net_data_minimize(net_data);
210 }
211
212 void
endnetent_p(struct net_data * net_data)213 endnetent_p(struct net_data *net_data) {
214 struct irs_nw *nw;
215
216 if ((net_data != NULL) && ((nw = net_data->nw) != NULL))
217 (*nw->minimize)(nw);
218 }
219
220 /* Private */
221
222 static struct net_data *
init()223 init() {
224 struct net_data *net_data;
225
226 if (!(net_data = net_data_init(NULL)))
227 goto error;
228 if (!net_data->nw) {
229 net_data->nw = (*net_data->irs->nw_map)(net_data->irs);
230
231 if (!net_data->nw || !net_data->res) {
232 error:
233 errno = EIO;
234 return (NULL);
235 }
236 (*net_data->nw->res_set)(net_data->nw, net_data->res, NULL);
237 }
238
239 return (net_data);
240 }
241
242 static void
freepvt(struct net_data * net_data)243 freepvt(struct net_data *net_data) {
244 if (net_data->nw_data) {
245 free(net_data->nw_data);
246 net_data->nw_data = NULL;
247 }
248 }
249
250 static struct netent *
fakeaddr(const char * name,int af,struct net_data * net_data)251 fakeaddr(const char *name, int af, struct net_data *net_data) {
252 struct pvt *pvt;
253 const char *cp;
254 u_long tmp;
255
256 if (af != AF_INET) {
257 /* XXX should support IPv6 some day */
258 errno = EAFNOSUPPORT;
259 RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
260 return (NULL);
261 }
262 if (!isascii((unsigned char)(name[0])) ||
263 !isdigit((unsigned char)(name[0])))
264 return (NULL);
265 for (cp = name; *cp; ++cp)
266 if (!isascii(*cp) || (!isdigit((unsigned char)*cp) && *cp != '.'))
267 return (NULL);
268 if (*--cp == '.')
269 return (NULL);
270
271 /* All-numeric, no dot at the end. */
272
273 tmp = inet_network(name);
274 if (tmp == INADDR_NONE) {
275 RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
276 return (NULL);
277 }
278
279 /* Valid network number specified.
280 * Fake up a netent as if we'd actually
281 * done a lookup.
282 */
283 freepvt(net_data);
284 net_data->nw_data = malloc(sizeof (struct pvt));
285 if (!net_data->nw_data) {
286 errno = ENOMEM;
287 RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
288 return (NULL);
289 }
290 pvt = net_data->nw_data;
291
292 strncpy(pvt->name, name, MAXDNAME);
293 pvt->name[MAXDNAME] = '\0';
294 pvt->netent.n_name = pvt->name;
295 pvt->netent.n_addrtype = AF_INET;
296 pvt->netent.n_aliases = pvt->aliases;
297 pvt->aliases[0] = NULL;
298 pvt->netent.n_net = tmp;
299
300 return (&pvt->netent);
301 }
302
303 static struct netent *
nw_to_net(struct nwent * nwent,struct net_data * net_data)304 nw_to_net(struct nwent *nwent, struct net_data *net_data) {
305 struct pvt *pvt;
306 u_long addr = 0;
307 int i;
308 int msbyte;
309
310 if (!nwent || nwent->n_addrtype != AF_INET)
311 return (NULL);
312 freepvt(net_data);
313 net_data->nw_data = malloc(sizeof (struct pvt));
314 if (!net_data->nw_data) {
315 errno = ENOMEM;
316 RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
317 return (NULL);
318 }
319 pvt = net_data->nw_data;
320 pvt->netent.n_name = nwent->n_name;
321 pvt->netent.n_aliases = nwent->n_aliases;
322 pvt->netent.n_addrtype = nwent->n_addrtype;
323
324 /*%
325 * What this code does: Converts net addresses from network to host form.
326 *
327 * msbyte: the index of the most significant byte in the n_addr array.
328 *
329 * Shift bytes in significant order into addr. When all signicant
330 * bytes are in, zero out bits in the LSB that are not part of the network.
331 */
332 msbyte = nwent->n_length / 8 +
333 ((nwent->n_length % 8) != 0 ? 1 : 0) - 1;
334 for (i = 0; i <= msbyte; i++)
335 addr = (addr << 8) | ((unsigned char *)nwent->n_addr)[i];
336 i = (32 - nwent->n_length) % 8;
337 if (i != 0)
338 addr &= ~((1 << (i + 1)) - 1);
339 pvt->netent.n_net = addr;
340 return (&pvt->netent);
341 }
342
343 #endif /*__BIND_NOSTATIC*/
344
345 /*! \file */
346