(_nss_dns_getcanonname_r): Don't use CNAME records, we better follow the chain of...
[glibc.git] / nss / digits_dots.c
blob9576dd53b74b1cc3298f034b68ccefe5b948069f
1 /* Copyright (C) 1997, 1999, 2000, 2001, 2004 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by H.J. Lu <hjl@gnu.ai.mit.edu>, 1997.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <assert.h>
21 #include <errno.h>
22 #include <string.h>
23 #include <stdlib.h>
24 #include <ctype.h>
25 #include <wctype.h>
26 #include <resolv.h>
27 #include <netdb.h>
28 #include <arpa/inet.h>
29 #include "nsswitch.h"
31 #ifdef USE_NSCD
32 # define inet_aton __inet_aton
33 # include <nscd/nscd_proto.h>
34 #endif
36 int
37 __nss_hostname_digits_dots (const char *name, struct hostent *resbuf,
38 char **buffer, size_t *buffer_size,
39 size_t buflen, struct hostent **result,
40 enum nss_status *status, int af, int *h_errnop)
42 int save;
44 /* We have to test for the use of IPv6 which can only be done by
45 examining `_res'. */
46 if (__res_maybe_init (&_res, 0) == -1)
48 if (h_errnop)
49 *h_errnop = NETDB_INTERNAL;
50 *result = NULL;
51 return -1;
55 * disallow names consisting only of digits/dots, unless
56 * they end in a dot.
58 if (isdigit (name[0]) || isxdigit (name[0]) || name[0] == ':')
60 const char *cp;
61 char *hostname;
62 typedef unsigned char host_addr_t[16];
63 host_addr_t *host_addr;
64 typedef char *host_addr_list_t[2];
65 host_addr_list_t *h_addr_ptrs;
66 char **h_alias_ptr;
67 size_t size_needed;
68 int addr_size;
70 switch (af)
72 case AF_INET:
73 addr_size = INADDRSZ;
74 break;
76 case AF_INET6:
77 addr_size = IN6ADDRSZ;
78 break;
80 default:
81 af = (_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET;
82 addr_size = af == AF_INET6 ? IN6ADDRSZ : INADDRSZ;
83 break;
86 size_needed = (sizeof (*host_addr)
87 + sizeof (*h_addr_ptrs) + strlen (name) + 1);
89 if (buffer_size == NULL)
91 if (buflen < size_needed)
93 if (h_errnop != NULL)
94 *h_errnop = TRY_AGAIN;
95 __set_errno (ERANGE);
96 goto done;
99 else if (buffer_size != NULL && *buffer_size < size_needed)
101 char *new_buf;
102 *buffer_size = size_needed;
103 new_buf = (char *) realloc (*buffer, *buffer_size);
105 if (new_buf == NULL)
107 save = errno;
108 free (*buffer);
109 *buffer = NULL;
110 *buffer_size = 0;
111 __set_errno (save);
112 if (h_errnop != NULL)
113 *h_errnop = TRY_AGAIN;
114 *result = NULL;
115 goto done;
117 *buffer = new_buf;
120 memset (*buffer, '\0', size_needed);
122 host_addr = (host_addr_t *) *buffer;
123 h_addr_ptrs = (host_addr_list_t *)
124 ((char *) host_addr + sizeof (*host_addr));
125 h_alias_ptr = (char **) ((char *) h_addr_ptrs + sizeof (*h_addr_ptrs));
126 hostname = (char *) h_alias_ptr + sizeof (*h_alias_ptr);
128 if (isdigit (name[0]))
130 for (cp = name;; ++cp)
132 if (*cp == '\0')
134 int ok;
136 if (*--cp == '.')
137 break;
139 /* All-numeric, no dot at the end. Fake up a hostent as if
140 we'd actually done a lookup. What if someone types
141 255.255.255.255? The test below will succeed
142 spuriously... ??? */
143 if (af == AF_INET)
144 ok = __inet_aton (name, (struct in_addr *) host_addr);
145 else
147 assert (af == AF_INET6);
148 ok = inet_pton (af, name, host_addr) > 0;
150 if (! ok)
152 *h_errnop = HOST_NOT_FOUND;
153 if (buffer_size)
154 *result = NULL;
155 goto done;
158 resbuf->h_name = strcpy (hostname, name);
159 h_alias_ptr[0] = NULL;
160 resbuf->h_aliases = h_alias_ptr;
161 (*h_addr_ptrs)[0] = (char *) host_addr;
162 (*h_addr_ptrs)[1] = NULL;
163 resbuf->h_addr_list = *h_addr_ptrs;
164 if (af == AF_INET && (_res.options & RES_USE_INET6))
166 /* We need to change the IP v4 address into the
167 IP v6 address. */
168 char tmp[INADDRSZ];
169 char *p = (char *) host_addr;
170 int i;
172 /* Save a copy of the IP v4 address. */
173 memcpy (tmp, host_addr, INADDRSZ);
174 /* Mark this ipv6 addr as a mapped ipv4. */
175 for (i = 0; i < 10; i++)
176 *p++ = 0x00;
177 *p++ = 0xff;
178 *p++ = 0xff;
179 /* Copy the IP v4 address. */
180 memcpy (p, tmp, INADDRSZ);
181 resbuf->h_addrtype = AF_INET6;
182 resbuf->h_length = IN6ADDRSZ;
184 else
186 resbuf->h_addrtype = af;
187 resbuf->h_length = addr_size;
189 if (h_errnop != NULL)
190 *h_errnop = NETDB_SUCCESS;
191 if (buffer_size == NULL)
192 *status = NSS_STATUS_SUCCESS;
193 else
194 *result = resbuf;
195 goto done;
198 if (!isdigit (*cp) && *cp != '.')
199 break;
203 if ((isxdigit (name[0]) && strchr (name, ':') != NULL) || name[0] == ':')
205 const char *cp;
206 char *hostname;
207 typedef unsigned char host_addr_t[16];
208 host_addr_t *host_addr;
209 typedef char *host_addr_list_t[2];
210 host_addr_list_t *h_addr_ptrs;
211 size_t size_needed;
212 int addr_size;
214 switch (af)
216 default:
217 af = (_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET;
218 if (af == AF_INET6)
220 addr_size = IN6ADDRSZ;
221 break;
223 /* FALLTHROUGH */
225 case AF_INET:
226 /* This is not possible. We cannot represent an IPv6 address
227 in an `struct in_addr' variable. */
228 *h_errnop = HOST_NOT_FOUND;
229 *result = NULL;
230 goto done;
232 case AF_INET6:
233 addr_size = IN6ADDRSZ;
234 break;
237 size_needed = (sizeof (*host_addr)
238 + sizeof (*h_addr_ptrs) + strlen (name) + 1);
240 if (buffer_size == NULL && buflen < size_needed)
242 if (h_errnop != NULL)
243 *h_errnop = TRY_AGAIN;
244 __set_errno (ERANGE);
245 goto done;
247 else if (buffer_size != NULL && *buffer_size < size_needed)
249 char *new_buf;
250 *buffer_size = size_needed;
251 new_buf = realloc (*buffer, *buffer_size);
253 if (new_buf == NULL)
255 save = errno;
256 free (*buffer);
257 __set_errno (save);
258 *buffer = NULL;
259 *buffer_size = 0;
260 *result = NULL;
261 goto done;
263 *buffer = new_buf;
266 memset (*buffer, '\0', size_needed);
268 host_addr = (host_addr_t *) *buffer;
269 h_addr_ptrs = (host_addr_list_t *)
270 ((char *) host_addr + sizeof (*host_addr));
271 hostname = (char *) h_addr_ptrs + sizeof (*h_addr_ptrs);
273 for (cp = name;; ++cp)
275 if (!*cp)
277 if (*--cp == '.')
278 break;
280 /* All-IPv6-legal, no dot at the end. Fake up a
281 hostent as if we'd actually done a lookup. */
282 if (inet_pton (AF_INET6, name, host_addr) <= 0)
284 *h_errnop = HOST_NOT_FOUND;
285 if (buffer_size)
286 *result = NULL;
287 goto done;
290 resbuf->h_name = strcpy (hostname, name);
291 h_alias_ptr[0] = NULL;
292 resbuf->h_aliases = h_alias_ptr;
293 (*h_addr_ptrs)[0] = (char *) host_addr;
294 (*h_addr_ptrs)[1] = (char *) 0;
295 resbuf->h_addr_list = *h_addr_ptrs;
296 resbuf->h_addrtype = AF_INET6;
297 resbuf->h_length = addr_size;
298 *h_errnop = NETDB_SUCCESS;
299 if (buffer_size == NULL)
300 *status = NSS_STATUS_SUCCESS;
301 else
302 *result = resbuf;
303 goto done;
306 if (!isxdigit (*cp) && *cp != ':' && *cp != '.')
307 break;
312 return 0;
314 done:
315 return 1;
317 libc_hidden_def (__nss_hostname_digits_dots)