1 /* Copyright (C) 1998-2005, 2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
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
29 #include <arpa/nameser.h>
30 #include <not-cancel.h>
32 #include "nscd-client.h"
33 #include "nscd_proto.h"
35 int __nss_not_use_nscd_hosts;
37 static int nscd_gethst_r (const char *key, size_t keylen, request_type type,
38 struct hostent *resultbuf, char *buffer,
39 size_t buflen, struct hostent **result,
40 int *h_errnop) internal_function;
44 __nscd_gethostbyname_r (const char *name, struct hostent *resultbuf,
45 char *buffer, size_t buflen, struct hostent **result,
50 reqtype = (_res.options & RES_USE_INET6) ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
52 return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
53 buffer, buflen, result, h_errnop);
58 __nscd_gethostbyname2_r (const char *name, int af, struct hostent *resultbuf,
59 char *buffer, size_t buflen, struct hostent **result,
64 reqtype = af == AF_INET6 ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
66 return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
67 buffer, buflen, result, h_errnop);
72 __nscd_gethostbyaddr_r (const void *addr, socklen_t len, int type,
73 struct hostent *resultbuf, char *buffer, size_t buflen,
74 struct hostent **result, int *h_errnop)
78 if (!((len == INADDRSZ && type == AF_INET)
79 || (len == IN6ADDRSZ && type == AF_INET6)))
80 /* LEN and TYPE do not match. */
83 reqtype = type == AF_INET6 ? GETHOSTBYADDRv6 : GETHOSTBYADDR;
85 return nscd_gethst_r (addr, len, reqtype, resultbuf, buffer, buflen, result,
90 libc_locked_map_ptr (, __hst_map_handle) attribute_hidden;
91 /* Note that we only free the structure if necessary. The memory
92 mapping is not removed since it is not visible to the malloc
94 libc_freeres_fn (hst_map_free)
96 if (__hst_map_handle.mapped != NO_MAPPING)
98 void *p = __hst_map_handle.mapped;
99 __hst_map_handle.mapped = NO_MAPPING;
107 nscd_gethst_r (const char *key, size_t keylen, request_type type,
108 struct hostent *resultbuf, char *buffer, size_t buflen,
109 struct hostent **result, int *h_errnop)
114 /* If the mapping is available, try to search there instead of
115 communicating with the nscd. */
116 struct mapped_database *mapped;
117 mapped = __nscd_get_map_ref (GETFDHST, "hosts", &__hst_map_handle,
121 const hst_response_header *hst_resp = NULL;
122 const char *h_name = NULL;
123 const uint32_t *aliases_len = NULL;
124 const char *addr_list = NULL;
125 size_t addr_list_len = 0;
127 const char *recend = (const char *) ~UINTMAX_C (0);
129 if (mapped != NO_MAPPING)
131 const struct datahead *found = __nscd_cache_search (type, key, keylen,
135 hst_resp = &found->data[0].hstdata;
136 h_name = (char *) (hst_resp + 1);
137 aliases_len = (uint32_t *) (h_name + hst_resp->h_name_len);
138 addr_list = ((char *) aliases_len
139 + hst_resp->h_aliases_cnt * sizeof (uint32_t));
140 addr_list_len = hst_resp->h_addr_list_cnt * INADDRSZ;
142 #ifndef _STRING_ARCH_unaligned
143 /* The aliases_len array in the mapped database might very
144 well be unaligned. We will access it word-wise so on
145 platforms which do not tolerate unaligned accesses we
146 need to make an aligned copy. */
147 if (((uintptr_t) aliases_len & (__alignof__ (*aliases_len) - 1))
150 uint32_t *tmp = alloca (hst_resp->h_aliases_cnt
151 * sizeof (uint32_t));
152 aliases_len = memcpy (tmp, aliases_len,
153 hst_resp->h_aliases_cnt
154 * sizeof (uint32_t));
157 if (type != GETHOSTBYADDR && type != GETHOSTBYNAME)
159 if (hst_resp->h_length == INADDRSZ)
160 addr_list += addr_list_len;
161 addr_list_len = hst_resp->h_addr_list_cnt * IN6ADDRSZ;
163 recend = (const char *) found->data + found->recsize;
164 if (__builtin_expect ((const char *) addr_list + addr_list_len
170 hst_response_header hst_resp_mem;
171 if (hst_resp == NULL)
173 sock = __nscd_open_socket (key, keylen, type, &hst_resp_mem,
174 sizeof (hst_resp_mem));
177 __nss_not_use_nscd_hosts = 1;
181 hst_resp = &hst_resp_mem;
184 /* No value found so far. */
187 if (__builtin_expect (hst_resp->found == -1, 0))
189 /* The daemon does not cache this database. */
190 __nss_not_use_nscd_hosts = 1;
194 if (hst_resp->found == 1)
205 /* A first check whether the buffer is sufficiently large is possible. */
206 /* Now allocate the buffer the array for the group members. We must
207 align the pointer and the base of the h_addr_list pointers. */
208 align1 = ((__alignof__ (char *) - (cp - ((char *) 0)))
209 & (__alignof__ (char *) - 1));
210 align2 = ((__alignof__ (char *) - ((cp + align1 + hst_resp->h_name_len)
212 & (__alignof__ (char *) - 1));
213 if (buflen < (align1 + hst_resp->h_name_len + align2
214 + ((hst_resp->h_aliases_cnt + hst_resp->h_addr_list_cnt
217 + hst_resp->h_addr_list_cnt * (type == AF_INET
218 ? INADDRSZ : IN6ADDRSZ)))
221 *h_errnop = NETDB_INTERNAL;
222 __set_errno (ERANGE);
228 /* Prepare the result as far as we can. */
229 resultbuf->h_aliases = (char **) cp;
230 cp += (hst_resp->h_aliases_cnt + 1) * sizeof (char *);
231 resultbuf->h_addr_list = (char **) cp;
232 cp += (hst_resp->h_addr_list_cnt + 1) * sizeof (char *);
234 resultbuf->h_name = cp;
235 cp += hst_resp->h_name_len + align2;
237 if (type == GETHOSTBYADDR || type == GETHOSTBYNAME)
239 resultbuf->h_addrtype = AF_INET;
240 resultbuf->h_length = INADDRSZ;
244 resultbuf->h_addrtype = AF_INET6;
245 resultbuf->h_length = IN6ADDRSZ;
247 for (cnt = 0; cnt < hst_resp->h_addr_list_cnt; ++cnt)
249 resultbuf->h_addr_list[cnt] = cp;
250 cp += resultbuf->h_length;
252 resultbuf->h_addr_list[cnt] = NULL;
256 vec[0].iov_base = resultbuf->h_name;
257 vec[0].iov_len = hst_resp->h_name_len;
258 total_len = hst_resp->h_name_len;
261 if (hst_resp->h_aliases_cnt > 0)
263 aliases_len = alloca (hst_resp->h_aliases_cnt
264 * sizeof (uint32_t));
265 vec[n].iov_base = (void *) aliases_len;
266 vec[n].iov_len = hst_resp->h_aliases_cnt * sizeof (uint32_t);
268 total_len += hst_resp->h_aliases_cnt * sizeof (uint32_t);
272 if (type == GETHOSTBYADDR || type == GETHOSTBYNAME)
274 vec[n].iov_base = resultbuf->h_addr_list[0];
275 vec[n].iov_len = hst_resp->h_addr_list_cnt * INADDRSZ;
277 total_len += hst_resp->h_addr_list_cnt * INADDRSZ;
283 if (hst_resp->h_length == INADDRSZ)
285 ignore = alloca (hst_resp->h_addr_list_cnt * INADDRSZ);
286 vec[n].iov_base = ignore;
287 vec[n].iov_len = hst_resp->h_addr_list_cnt * INADDRSZ;
289 total_len += hst_resp->h_addr_list_cnt * INADDRSZ;
294 vec[n].iov_base = resultbuf->h_addr_list[0];
295 vec[n].iov_len = hst_resp->h_addr_list_cnt * IN6ADDRSZ;
297 total_len += hst_resp->h_addr_list_cnt * IN6ADDRSZ;
302 if ((size_t) __readvall (sock, vec, n) != total_len)
307 memcpy (resultbuf->h_name, h_name, hst_resp->h_name_len);
308 memcpy (resultbuf->h_addr_list[0], addr_list, addr_list_len);
311 /* Now we also can read the aliases. */
313 for (cnt = 0; cnt < hst_resp->h_aliases_cnt; ++cnt)
315 resultbuf->h_aliases[cnt] = cp;
316 cp += aliases_len[cnt];
317 total_len += aliases_len[cnt];
319 resultbuf->h_aliases[cnt] = NULL;
321 if (__builtin_expect ((const char *) addr_list + addr_list_len
322 + total_len > recend, 0))
324 /* See whether this would exceed the buffer capacity. */
325 if (__builtin_expect (cp > buffer + buflen, 0))
328 /* And finally read the aliases. */
329 if (addr_list == NULL)
332 || ((size_t) __readall (sock, resultbuf->h_aliases[0], total_len)
341 memcpy (resultbuf->h_aliases[0],
342 (const char *) addr_list + addr_list_len, total_len);
344 /* Try to detect corrupt databases. */
345 if (resultbuf->h_name[hst_resp->h_name_len - 1] != '\0'
346 || ({for (cnt = 0; cnt < hst_resp->h_aliases_cnt; ++cnt)
347 if (resultbuf->h_aliases[cnt][aliases_len[cnt] - 1]
350 cnt < hst_resp->h_aliases_cnt; }))
351 /* We cannot use the database. */
360 /* Store the error number. */
361 *h_errnop = hst_resp->error;
363 /* The `errno' to some value != ERANGE. */
364 __set_errno (ENOENT);
365 /* Even though we have not found anything, the result is zero. */
371 close_not_cancel_no_status (sock);
373 if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0 && retval != -1)
375 /* When we come here this means there has been a GC cycle while we
376 were looking for the data. This means the data might have been
377 inconsistent. Retry if possible. */
378 if ((gc_cycle & 1) != 0 || ++nretries == 5)
380 /* nscd is just running gc now. Disable using the mapping. */
381 __nscd_unmap (mapped);