1 | /* Copyright (C) 1997-2018 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. |
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 |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <assert.h> |
20 | #include <errno.h> |
21 | #include <string.h> |
22 | #include <stdlib.h> |
23 | #include <ctype.h> |
24 | #include <wctype.h> |
25 | #include <resolv/resolv-internal.h> |
26 | #include <resolv/resolv_context.h> |
27 | #include <netdb.h> |
28 | #include <arpa/inet.h> |
29 | #include "nsswitch.h" |
30 | |
31 | #ifdef USE_NSCD |
32 | # define inet_aton __inet_aton |
33 | # include <nscd/nscd_proto.h> |
34 | #endif |
35 | |
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) |
41 | { |
42 | /* We have to test for the use of IPv6 which can only be done by |
43 | examining `_res'. */ |
44 | struct resolv_context *ctx = __resolv_context_get (); |
45 | if (ctx == NULL) |
46 | { |
47 | if (h_errnop) |
48 | *h_errnop = NETDB_INTERNAL; |
49 | if (buffer_size == NULL) |
50 | *status = NSS_STATUS_TRYAGAIN; |
51 | else |
52 | *result = NULL; |
53 | return -1; |
54 | } |
55 | int ret = __nss_hostname_digits_dots_context |
56 | (ctx, name, resbuf, buffer, buffer_size, buflen, |
57 | result, status, af, h_errnop); |
58 | __resolv_context_put (ctx); |
59 | return ret; |
60 | } |
61 | |
62 | int |
63 | __nss_hostname_digits_dots_context (struct resolv_context *ctx, |
64 | const char *name, struct hostent *resbuf, |
65 | char **buffer, size_t *buffer_size, |
66 | size_t buflen, struct hostent **result, |
67 | enum nss_status *status, int af, int *h_errnop) |
68 | { |
69 | int save; |
70 | |
71 | /* |
72 | * disallow names consisting only of digits/dots, unless |
73 | * they end in a dot. |
74 | */ |
75 | if (isdigit (name[0]) || isxdigit (name[0]) || name[0] == ':') |
76 | { |
77 | const char *cp; |
78 | char *hostname; |
79 | typedef unsigned char host_addr_t[16]; |
80 | host_addr_t *host_addr; |
81 | typedef char *host_addr_list_t[2]; |
82 | host_addr_list_t *h_addr_ptrs; |
83 | char **h_alias_ptr; |
84 | size_t size_needed; |
85 | int addr_size; |
86 | |
87 | switch (af) |
88 | { |
89 | case AF_INET: |
90 | addr_size = INADDRSZ; |
91 | break; |
92 | |
93 | case AF_INET6: |
94 | addr_size = IN6ADDRSZ; |
95 | break; |
96 | |
97 | default: |
98 | af = res_use_inet6 () ? AF_INET6 : AF_INET; |
99 | addr_size = af == AF_INET6 ? IN6ADDRSZ : INADDRSZ; |
100 | break; |
101 | } |
102 | |
103 | size_needed = (sizeof (*host_addr) |
104 | + sizeof (*h_addr_ptrs) |
105 | + sizeof (*h_alias_ptr) + strlen (name) + 1); |
106 | |
107 | if (buffer_size == NULL) |
108 | { |
109 | if (buflen < size_needed) |
110 | { |
111 | *status = NSS_STATUS_TRYAGAIN; |
112 | if (h_errnop != NULL) |
113 | *h_errnop = NETDB_INTERNAL; |
114 | __set_errno (ERANGE); |
115 | goto done; |
116 | } |
117 | } |
118 | else if (buffer_size != NULL && *buffer_size < size_needed) |
119 | { |
120 | char *new_buf; |
121 | *buffer_size = size_needed; |
122 | new_buf = (char *) realloc (*buffer, *buffer_size); |
123 | |
124 | if (new_buf == NULL) |
125 | { |
126 | save = errno; |
127 | free (*buffer); |
128 | *buffer = NULL; |
129 | *buffer_size = 0; |
130 | __set_errno (save); |
131 | if (h_errnop != NULL) |
132 | *h_errnop = NETDB_INTERNAL; |
133 | *result = NULL; |
134 | goto done; |
135 | } |
136 | *buffer = new_buf; |
137 | } |
138 | |
139 | memset (*buffer, '\0', size_needed); |
140 | |
141 | host_addr = (host_addr_t *) *buffer; |
142 | h_addr_ptrs = (host_addr_list_t *) |
143 | ((char *) host_addr + sizeof (*host_addr)); |
144 | h_alias_ptr = (char **) ((char *) h_addr_ptrs + sizeof (*h_addr_ptrs)); |
145 | hostname = (char *) h_alias_ptr + sizeof (*h_alias_ptr); |
146 | |
147 | if (isdigit (name[0])) |
148 | { |
149 | for (cp = name;; ++cp) |
150 | { |
151 | if (*cp == '\0') |
152 | { |
153 | int ok; |
154 | |
155 | if (*--cp == '.') |
156 | break; |
157 | |
158 | /* All-numeric, no dot at the end. Fake up a hostent as if |
159 | we'd actually done a lookup. What if someone types |
160 | 255.255.255.255? The test below will succeed |
161 | spuriously... ??? */ |
162 | if (af == AF_INET) |
163 | ok = __inet_aton (name, (struct in_addr *) host_addr); |
164 | else |
165 | { |
166 | assert (af == AF_INET6); |
167 | ok = inet_pton (af, name, host_addr) > 0; |
168 | } |
169 | if (! ok) |
170 | { |
171 | *h_errnop = HOST_NOT_FOUND; |
172 | if (buffer_size == NULL) |
173 | *status = NSS_STATUS_NOTFOUND; |
174 | else |
175 | *result = NULL; |
176 | goto done; |
177 | } |
178 | |
179 | resbuf->h_name = strcpy (hostname, name); |
180 | h_alias_ptr[0] = NULL; |
181 | resbuf->h_aliases = h_alias_ptr; |
182 | (*h_addr_ptrs)[0] = (char *) host_addr; |
183 | (*h_addr_ptrs)[1] = NULL; |
184 | resbuf->h_addr_list = *h_addr_ptrs; |
185 | if (af == AF_INET && res_use_inet6 ()) |
186 | { |
187 | /* We need to change the IP v4 address into the |
188 | IP v6 address. */ |
189 | char tmp[INADDRSZ]; |
190 | char *p = (char *) host_addr; |
191 | int i; |
192 | |
193 | /* Save a copy of the IP v4 address. */ |
194 | memcpy (tmp, host_addr, INADDRSZ); |
195 | /* Mark this ipv6 addr as a mapped ipv4. */ |
196 | for (i = 0; i < 10; i++) |
197 | *p++ = 0x00; |
198 | *p++ = 0xff; |
199 | *p++ = 0xff; |
200 | /* Copy the IP v4 address. */ |
201 | memcpy (p, tmp, INADDRSZ); |
202 | resbuf->h_addrtype = AF_INET6; |
203 | resbuf->h_length = IN6ADDRSZ; |
204 | } |
205 | else |
206 | { |
207 | resbuf->h_addrtype = af; |
208 | resbuf->h_length = addr_size; |
209 | } |
210 | if (h_errnop != NULL) |
211 | *h_errnop = NETDB_SUCCESS; |
212 | if (buffer_size == NULL) |
213 | *status = NSS_STATUS_SUCCESS; |
214 | else |
215 | *result = resbuf; |
216 | goto done; |
217 | } |
218 | |
219 | if (!isdigit (*cp) && *cp != '.') |
220 | break; |
221 | } |
222 | } |
223 | |
224 | if ((isxdigit (name[0]) && strchr (name, ':') != NULL) || name[0] == ':') |
225 | { |
226 | switch (af) |
227 | { |
228 | default: |
229 | af = res_use_inet6 () ? AF_INET6 : AF_INET; |
230 | if (af == AF_INET6) |
231 | { |
232 | addr_size = IN6ADDRSZ; |
233 | break; |
234 | } |
235 | /* FALLTHROUGH */ |
236 | |
237 | case AF_INET: |
238 | /* This is not possible. We cannot represent an IPv6 address |
239 | in an `struct in_addr' variable. */ |
240 | *h_errnop = HOST_NOT_FOUND; |
241 | if (buffer_size == NULL) |
242 | *status = NSS_STATUS_NOTFOUND; |
243 | else |
244 | *result = NULL; |
245 | goto done; |
246 | |
247 | case AF_INET6: |
248 | addr_size = IN6ADDRSZ; |
249 | break; |
250 | } |
251 | |
252 | for (cp = name;; ++cp) |
253 | { |
254 | if (!*cp) |
255 | { |
256 | if (*--cp == '.') |
257 | break; |
258 | |
259 | /* All-IPv6-legal, no dot at the end. Fake up a |
260 | hostent as if we'd actually done a lookup. */ |
261 | if (inet_pton (AF_INET6, name, host_addr) <= 0) |
262 | { |
263 | *h_errnop = HOST_NOT_FOUND; |
264 | if (buffer_size == NULL) |
265 | *status = NSS_STATUS_NOTFOUND; |
266 | else |
267 | *result = NULL; |
268 | goto done; |
269 | } |
270 | |
271 | resbuf->h_name = strcpy (hostname, name); |
272 | h_alias_ptr[0] = NULL; |
273 | resbuf->h_aliases = h_alias_ptr; |
274 | (*h_addr_ptrs)[0] = (char *) host_addr; |
275 | (*h_addr_ptrs)[1] = (char *) 0; |
276 | resbuf->h_addr_list = *h_addr_ptrs; |
277 | resbuf->h_addrtype = AF_INET6; |
278 | resbuf->h_length = addr_size; |
279 | *h_errnop = NETDB_SUCCESS; |
280 | if (buffer_size == NULL) |
281 | *status = NSS_STATUS_SUCCESS; |
282 | else |
283 | *result = resbuf; |
284 | goto done; |
285 | } |
286 | |
287 | if (!isxdigit (*cp) && *cp != ':' && *cp != '.') |
288 | break; |
289 | } |
290 | } |
291 | } |
292 | |
293 | return 0; |
294 | |
295 | done: |
296 | return 1; |
297 | } |
298 | libc_hidden_def (__nss_hostname_digits_dots) |
299 | |