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b168057a | 1 | /* Copyright (C) 2007-2015 Free Software Foundation, Inc. |
b21fa963 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2007. | |
4 | ||
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. | |
9 | ||
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. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
b21fa963 | 18 | |
f2962a71 | 19 | #include <assert.h> |
b21fa963 UD |
20 | #include <errno.h> |
21 | #include <string.h> | |
22 | #include <not-cancel.h> | |
eb96ffb0 | 23 | #include <_itoa.h> |
e054f494 | 24 | #include <stdint.h> |
b21fa963 UD |
25 | |
26 | #include "nscd-client.h" | |
27 | #include "nscd_proto.h" | |
28 | ||
29 | ||
30 | int __nss_not_use_nscd_services; | |
31 | ||
32 | ||
33 | static int nscd_getserv_r (const char *crit, size_t critlen, const char *proto, | |
34 | request_type type, struct servent *resultbuf, | |
35 | char *buf, size_t buflen, struct servent **result); | |
36 | ||
37 | ||
38 | int | |
39 | __nscd_getservbyname_r (const char *name, const char *proto, | |
40 | struct servent *result_buf, char *buf, size_t buflen, | |
41 | struct servent **result) | |
42 | { | |
43 | return nscd_getserv_r (name, strlen (name), proto, GETSERVBYNAME, result_buf, | |
44 | buf, buflen, result); | |
45 | } | |
46 | ||
47 | ||
48 | int | |
49 | __nscd_getservbyport_r (int port, const char *proto, | |
50 | struct servent *result_buf, char *buf, size_t buflen, | |
51 | struct servent **result) | |
52 | { | |
53 | char portstr[3 * sizeof (int) + 2]; | |
54 | portstr[sizeof (portstr) - 1] = '\0'; | |
55 | char *cp = _itoa_word (port, portstr + sizeof (portstr) - 1, 10, 0); | |
56 | ||
8ec3f656 | 57 | return nscd_getserv_r (cp, portstr + sizeof (portstr) - 1 - cp, proto, |
b21fa963 UD |
58 | GETSERVBYPORT, result_buf, buf, buflen, result); |
59 | } | |
60 | ||
61 | ||
62 | libc_locked_map_ptr (, __serv_map_handle) attribute_hidden; | |
63 | /* Note that we only free the structure if necessary. The memory | |
64 | mapping is not removed since it is not visible to the malloc | |
65 | handling. */ | |
66 | libc_freeres_fn (serv_map_free) | |
67 | { | |
68 | if (__serv_map_handle.mapped != NO_MAPPING) | |
69 | { | |
70 | void *p = __serv_map_handle.mapped; | |
71 | __serv_map_handle.mapped = NO_MAPPING; | |
72 | free (p); | |
73 | } | |
74 | } | |
75 | ||
76 | ||
77 | static int | |
78 | nscd_getserv_r (const char *crit, size_t critlen, const char *proto, | |
79 | request_type type, struct servent *resultbuf, | |
80 | char *buf, size_t buflen, struct servent **result) | |
81 | { | |
82 | int gc_cycle; | |
83 | int nretries = 0; | |
f2962a71 | 84 | size_t alloca_used = 0; |
b21fa963 UD |
85 | |
86 | /* If the mapping is available, try to search there instead of | |
87 | communicating with the nscd. */ | |
88 | struct mapped_database *mapped; | |
89 | mapped = __nscd_get_map_ref (GETFDSERV, "services", &__serv_map_handle, | |
90 | &gc_cycle); | |
91 | size_t protolen = proto == NULL ? 0 : strlen (proto); | |
92 | size_t keylen = critlen + 1 + protolen + 1; | |
f2962a71 UD |
93 | int alloca_key = __libc_use_alloca (keylen); |
94 | char *key; | |
95 | if (alloca_key) | |
96 | key = alloca_account (keylen, alloca_used); | |
97 | else | |
98 | { | |
99 | key = malloc (keylen); | |
100 | if (key == NULL) | |
101 | return -1; | |
102 | } | |
b21fa963 UD |
103 | memcpy (__mempcpy (__mempcpy (key, crit, critlen), |
104 | "/", 1), proto ?: "", protolen + 1); | |
105 | ||
106 | retry:; | |
b21fa963 UD |
107 | const char *s_name = NULL; |
108 | const char *s_proto = NULL; | |
f2962a71 | 109 | int alloca_aliases_len = 0; |
b21fa963 UD |
110 | const uint32_t *aliases_len = NULL; |
111 | const char *aliases_list = NULL; | |
112 | int retval = -1; | |
113 | const char *recend = (const char *) ~UINTMAX_C (0); | |
114 | int sock = -1; | |
1a77d37f JJ |
115 | serv_response_header serv_resp; |
116 | ||
b21fa963 UD |
117 | if (mapped != NO_MAPPING) |
118 | { | |
cfe1fc10 JJ |
119 | struct datahead *found = __nscd_cache_search (type, key, keylen, mapped, |
120 | sizeof serv_resp); | |
b21fa963 UD |
121 | |
122 | if (found != NULL) | |
123 | { | |
1a77d37f JJ |
124 | s_name = (char *) (&found->data[0].servdata + 1); |
125 | serv_resp = found->data[0].servdata; | |
126 | s_proto = s_name + serv_resp.s_name_len; | |
c8fc0c91 | 127 | alloca_aliases_len = 1; |
1a77d37f | 128 | aliases_len = (uint32_t *) (s_proto + serv_resp.s_proto_len); |
b21fa963 | 129 | aliases_list = ((char *) aliases_len |
1a77d37f JJ |
130 | + serv_resp.s_aliases_cnt * sizeof (uint32_t)); |
131 | recend = (const char *) found->data + found->recsize; | |
132 | /* Now check if we can trust serv_resp fields. If GC is | |
133 | in progress, it can contain anything. */ | |
134 | if (mapped->head->gc_cycle != gc_cycle) | |
135 | { | |
136 | retval = -2; | |
137 | goto out; | |
138 | } | |
3687a5a7 JJ |
139 | if (__builtin_expect ((const char *) aliases_len |
140 | + serv_resp.s_aliases_cnt * sizeof (uint32_t) | |
141 | > recend, 0)) | |
142 | goto out; | |
b21fa963 | 143 | |
27822ce6 | 144 | #if !_STRING_ARCH_unaligned |
b21fa963 UD |
145 | /* The aliases_len array in the mapped database might very |
146 | well be unaligned. We will access it word-wise so on | |
147 | platforms which do not tolerate unaligned accesses we | |
148 | need to make an aligned copy. */ | |
149 | if (((uintptr_t) aliases_len & (__alignof__ (*aliases_len) - 1)) | |
150 | != 0) | |
151 | { | |
f2962a71 UD |
152 | uint32_t *tmp; |
153 | alloca_aliases_len | |
154 | = __libc_use_alloca (alloca_used | |
155 | + (serv_resp.s_aliases_cnt | |
156 | * sizeof (uint32_t))); | |
157 | if (alloca_aliases_len) | |
c8fc0c91 UD |
158 | tmp = alloca_account (serv_resp.s_aliases_cnt |
159 | * sizeof (uint32_t), | |
160 | alloca_used); | |
f2962a71 UD |
161 | else |
162 | { | |
163 | tmp = malloc (serv_resp.s_aliases_cnt * sizeof (uint32_t)); | |
164 | if (tmp == NULL) | |
165 | { | |
166 | retval = ENOMEM; | |
167 | goto out; | |
168 | } | |
169 | } | |
b21fa963 | 170 | aliases_len = memcpy (tmp, aliases_len, |
1a77d37f | 171 | serv_resp.s_aliases_cnt |
b21fa963 UD |
172 | * sizeof (uint32_t)); |
173 | } | |
174 | #endif | |
b21fa963 UD |
175 | } |
176 | } | |
177 | ||
1a77d37f | 178 | if (s_name == NULL) |
b21fa963 | 179 | { |
1a77d37f JJ |
180 | sock = __nscd_open_socket (key, keylen, type, &serv_resp, |
181 | sizeof (serv_resp)); | |
b21fa963 UD |
182 | if (sock == -1) |
183 | { | |
184 | __nss_not_use_nscd_services = 1; | |
185 | goto out; | |
186 | } | |
b21fa963 UD |
187 | } |
188 | ||
189 | /* No value found so far. */ | |
190 | *result = NULL; | |
191 | ||
a1ffb40e | 192 | if (__glibc_unlikely (serv_resp.found == -1)) |
b21fa963 UD |
193 | { |
194 | /* The daemon does not cache this database. */ | |
195 | __nss_not_use_nscd_services = 1; | |
196 | goto out_close; | |
197 | } | |
198 | ||
1a77d37f | 199 | if (serv_resp.found == 1) |
b21fa963 UD |
200 | { |
201 | char *cp = buf; | |
202 | uintptr_t align1; | |
203 | uintptr_t align2; | |
204 | size_t total_len; | |
205 | ssize_t cnt; | |
206 | int n; | |
207 | ||
208 | /* A first check whether the buffer is sufficiently large is possible. */ | |
209 | /* Now allocate the buffer the array for the group members. We must | |
210 | align the pointer and the base of the h_addr_list pointers. */ | |
211 | align1 = ((__alignof__ (char *) - (cp - ((char *) 0))) | |
212 | & (__alignof__ (char *) - 1)); | |
1a77d37f JJ |
213 | align2 = ((__alignof__ (char *) - ((cp + align1 + serv_resp.s_name_len |
214 | + serv_resp.s_proto_len) | |
b21fa963 UD |
215 | - ((char *) 0))) |
216 | & (__alignof__ (char *) - 1)); | |
1a77d37f | 217 | if (buflen < (align1 + serv_resp.s_name_len + serv_resp.s_proto_len |
b21fa963 | 218 | + align2 |
1a77d37f | 219 | + (serv_resp.s_aliases_cnt + 1) * sizeof (char *))) |
b21fa963 UD |
220 | { |
221 | no_room: | |
222 | __set_errno (ERANGE); | |
223 | retval = ERANGE; | |
224 | goto out_close; | |
225 | } | |
226 | cp += align1; | |
227 | ||
228 | /* Prepare the result as far as we can. */ | |
229 | resultbuf->s_aliases = (char **) cp; | |
1a77d37f | 230 | cp += (serv_resp.s_aliases_cnt + 1) * sizeof (char *); |
b21fa963 UD |
231 | |
232 | resultbuf->s_name = cp; | |
1a77d37f | 233 | cp += serv_resp.s_name_len; |
b21fa963 | 234 | resultbuf->s_proto = cp; |
1a77d37f JJ |
235 | cp += serv_resp.s_proto_len + align2; |
236 | resultbuf->s_port = serv_resp.s_port; | |
b21fa963 UD |
237 | |
238 | if (s_name == NULL) | |
239 | { | |
240 | struct iovec vec[2]; | |
241 | ||
242 | vec[0].iov_base = resultbuf->s_name; | |
1a77d37f | 243 | vec[0].iov_len = serv_resp.s_name_len + serv_resp.s_proto_len; |
b21fa963 UD |
244 | total_len = vec[0].iov_len; |
245 | n = 1; | |
246 | ||
1a77d37f | 247 | if (serv_resp.s_aliases_cnt > 0) |
b21fa963 | 248 | { |
f2962a71 UD |
249 | assert (alloca_aliases_len == 0); |
250 | alloca_aliases_len | |
251 | = __libc_use_alloca (alloca_used | |
252 | + (serv_resp.s_aliases_cnt | |
253 | * sizeof (uint32_t))); | |
254 | if (alloca_aliases_len) | |
c8fc0c91 UD |
255 | aliases_len = alloca_account (serv_resp.s_aliases_cnt |
256 | * sizeof (uint32_t), | |
257 | alloca_used); | |
f2962a71 UD |
258 | else |
259 | { | |
260 | aliases_len = malloc (serv_resp.s_aliases_cnt | |
261 | * sizeof (uint32_t)); | |
262 | if (aliases_len == NULL) | |
263 | { | |
264 | retval = ENOMEM; | |
265 | goto out_close; | |
266 | } | |
267 | } | |
b21fa963 | 268 | vec[n].iov_base = (void *) aliases_len; |
1a77d37f | 269 | vec[n].iov_len = serv_resp.s_aliases_cnt * sizeof (uint32_t); |
b21fa963 | 270 | |
1a77d37f | 271 | total_len += serv_resp.s_aliases_cnt * sizeof (uint32_t); |
b21fa963 UD |
272 | ++n; |
273 | } | |
274 | ||
275 | if ((size_t) __readvall (sock, vec, n) != total_len) | |
276 | goto out_close; | |
277 | } | |
278 | else | |
279 | memcpy (resultbuf->s_name, s_name, | |
1a77d37f | 280 | serv_resp.s_name_len + serv_resp.s_proto_len); |
b21fa963 UD |
281 | |
282 | /* Now we also can read the aliases. */ | |
283 | total_len = 0; | |
1a77d37f | 284 | for (cnt = 0; cnt < serv_resp.s_aliases_cnt; ++cnt) |
b21fa963 UD |
285 | { |
286 | resultbuf->s_aliases[cnt] = cp; | |
287 | cp += aliases_len[cnt]; | |
288 | total_len += aliases_len[cnt]; | |
289 | } | |
290 | resultbuf->s_aliases[cnt] = NULL; | |
291 | ||
292 | if (__builtin_expect ((const char *) aliases_list + total_len > recend, | |
293 | 0)) | |
1a77d37f JJ |
294 | { |
295 | /* aliases_len array might contain garbage during nscd GC cycle, | |
296 | retry rather than fail in that case. */ | |
297 | if (aliases_list != NULL && mapped->head->gc_cycle != gc_cycle) | |
298 | retval = -2; | |
299 | goto out_close; | |
300 | } | |
301 | ||
b21fa963 | 302 | /* See whether this would exceed the buffer capacity. */ |
a1ffb40e | 303 | if (__glibc_unlikely (cp > buf + buflen)) |
1a77d37f JJ |
304 | { |
305 | /* aliases_len array might contain garbage during nscd GC cycle, | |
306 | retry rather than fail in that case. */ | |
307 | if (aliases_list != NULL && mapped->head->gc_cycle != gc_cycle) | |
308 | { | |
309 | retval = -2; | |
310 | goto out_close; | |
311 | } | |
312 | goto no_room; | |
313 | } | |
b21fa963 UD |
314 | |
315 | /* And finally read the aliases. */ | |
316 | if (aliases_list == NULL) | |
317 | { | |
318 | if (total_len == 0 | |
319 | || ((size_t) __readall (sock, resultbuf->s_aliases[0], total_len) | |
320 | == total_len)) | |
321 | { | |
322 | retval = 0; | |
323 | *result = resultbuf; | |
324 | } | |
325 | } | |
326 | else | |
327 | { | |
328 | memcpy (resultbuf->s_aliases[0], aliases_list, total_len); | |
329 | ||
330 | /* Try to detect corrupt databases. */ | |
1a77d37f JJ |
331 | if (resultbuf->s_name[serv_resp.s_name_len - 1] != '\0' |
332 | || resultbuf->s_proto[serv_resp.s_proto_len - 1] != '\0' | |
333 | || ({for (cnt = 0; cnt < serv_resp.s_aliases_cnt; ++cnt) | |
b21fa963 UD |
334 | if (resultbuf->s_aliases[cnt][aliases_len[cnt] - 1] |
335 | != '\0') | |
336 | break; | |
1a77d37f JJ |
337 | cnt < serv_resp.s_aliases_cnt; })) |
338 | { | |
339 | /* We cannot use the database. */ | |
340 | if (mapped->head->gc_cycle != gc_cycle) | |
341 | retval = -2; | |
342 | goto out_close; | |
343 | } | |
b21fa963 UD |
344 | |
345 | retval = 0; | |
346 | *result = resultbuf; | |
347 | } | |
348 | } | |
349 | else | |
350 | { | |
cfca0aa3 UD |
351 | /* Set errno to 0 to indicate no error, just no found record. */ |
352 | __set_errno (0); | |
b21fa963 UD |
353 | /* Even though we have not found anything, the result is zero. */ |
354 | retval = 0; | |
355 | } | |
356 | ||
357 | out_close: | |
358 | if (sock != -1) | |
359 | close_not_cancel_no_status (sock); | |
360 | out: | |
1a77d37f | 361 | if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0) |
b21fa963 UD |
362 | { |
363 | /* When we come here this means there has been a GC cycle while we | |
364 | were looking for the data. This means the data might have been | |
365 | inconsistent. Retry if possible. */ | |
1a77d37f | 366 | if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1) |
b21fa963 UD |
367 | { |
368 | /* nscd is just running gc now. Disable using the mapping. */ | |
1a77d37f JJ |
369 | if (atomic_decrement_val (&mapped->counter) == 0) |
370 | __nscd_unmap (mapped); | |
b21fa963 UD |
371 | mapped = NO_MAPPING; |
372 | } | |
373 | ||
1a77d37f | 374 | if (retval != -1) |
c8fc0c91 UD |
375 | { |
376 | if (!alloca_aliases_len) | |
f15f1e45 | 377 | free ((void *) aliases_len); |
c8fc0c91 UD |
378 | goto retry; |
379 | } | |
b21fa963 UD |
380 | } |
381 | ||
f2962a71 UD |
382 | if (!alloca_aliases_len) |
383 | free ((void *) aliases_len); | |
384 | if (!alloca_key) | |
385 | free (key); | |
386 | ||
b21fa963 UD |
387 | return retval; |
388 | } |