1 | /* Copyright (C) 1997-2016 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.h> |
26 | #include <netdb.h> |
27 | #include <arpa/inet.h> |
28 | #include "nsswitch.h" |
29 | |
30 | #ifdef USE_NSCD |
31 | # define inet_aton __inet_aton |
32 | # include <nscd/nscd_proto.h> |
33 | #endif |
34 | |
35 | int |
36 | __nss_hostname_digits_dots (const char *name, struct hostent *resbuf, |
37 | char **buffer, size_t *buffer_size, |
38 | size_t buflen, struct hostent **result, |
39 | enum nss_status *status, int af, int *h_errnop) |
40 | { |
41 | int save; |
42 | |
43 | /* We have to test for the use of IPv6 which can only be done by |
44 | examining `_res'. */ |
45 | if (__res_maybe_init (&_res, 0) == -1) |
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 | |
56 | /* |
57 | * disallow names consisting only of digits/dots, unless |
58 | * they end in a dot. |
59 | */ |
60 | if (isdigit (name[0]) || isxdigit (name[0]) || name[0] == ':') |
61 | { |
62 | const char *cp; |
63 | char *hostname; |
64 | typedef unsigned char host_addr_t[16]; |
65 | host_addr_t *host_addr; |
66 | typedef char *host_addr_list_t[2]; |
67 | host_addr_list_t *h_addr_ptrs; |
68 | char **h_alias_ptr; |
69 | size_t size_needed; |
70 | int addr_size; |
71 | |
72 | switch (af) |
73 | { |
74 | case AF_INET: |
75 | addr_size = INADDRSZ; |
76 | break; |
77 | |
78 | case AF_INET6: |
79 | addr_size = IN6ADDRSZ; |
80 | break; |
81 | |
82 | default: |
83 | af = (_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET; |
84 | addr_size = af == AF_INET6 ? IN6ADDRSZ : INADDRSZ; |
85 | break; |
86 | } |
87 | |
88 | size_needed = (sizeof (*host_addr) |
89 | + sizeof (*h_addr_ptrs) |
90 | + sizeof (*h_alias_ptr) + strlen (name) + 1); |
91 | |
92 | if (buffer_size == NULL) |
93 | { |
94 | if (buflen < size_needed) |
95 | { |
96 | *status = NSS_STATUS_TRYAGAIN; |
97 | if (h_errnop != NULL) |
98 | *h_errnop = NETDB_INTERNAL; |
99 | __set_errno (ERANGE); |
100 | goto done; |
101 | } |
102 | } |
103 | else if (buffer_size != NULL && *buffer_size < size_needed) |
104 | { |
105 | char *new_buf; |
106 | *buffer_size = size_needed; |
107 | new_buf = (char *) realloc (*buffer, *buffer_size); |
108 | |
109 | if (new_buf == NULL) |
110 | { |
111 | save = errno; |
112 | free (*buffer); |
113 | *buffer = NULL; |
114 | *buffer_size = 0; |
115 | __set_errno (save); |
116 | if (h_errnop != NULL) |
117 | *h_errnop = NETDB_INTERNAL; |
118 | *result = NULL; |
119 | goto done; |
120 | } |
121 | *buffer = new_buf; |
122 | } |
123 | |
124 | memset (*buffer, '\0', size_needed); |
125 | |
126 | host_addr = (host_addr_t *) *buffer; |
127 | h_addr_ptrs = (host_addr_list_t *) |
128 | ((char *) host_addr + sizeof (*host_addr)); |
129 | h_alias_ptr = (char **) ((char *) h_addr_ptrs + sizeof (*h_addr_ptrs)); |
130 | hostname = (char *) h_alias_ptr + sizeof (*h_alias_ptr); |
131 | |
132 | if (isdigit (name[0])) |
133 | { |
134 | for (cp = name;; ++cp) |
135 | { |
136 | if (*cp == '\0') |
137 | { |
138 | int ok; |
139 | |
140 | if (*--cp == '.') |
141 | break; |
142 | |
143 | /* All-numeric, no dot at the end. Fake up a hostent as if |
144 | we'd actually done a lookup. What if someone types |
145 | 255.255.255.255? The test below will succeed |
146 | spuriously... ??? */ |
147 | if (af == AF_INET) |
148 | ok = __inet_aton (name, (struct in_addr *) host_addr); |
149 | else |
150 | { |
151 | assert (af == AF_INET6); |
152 | ok = inet_pton (af, name, host_addr) > 0; |
153 | } |
154 | if (! ok) |
155 | { |
156 | *h_errnop = HOST_NOT_FOUND; |
157 | if (buffer_size == NULL) |
158 | *status = NSS_STATUS_NOTFOUND; |
159 | else |
160 | *result = NULL; |
161 | goto done; |
162 | } |
163 | |
164 | resbuf->h_name = strcpy (hostname, name); |
165 | h_alias_ptr[0] = NULL; |
166 | resbuf->h_aliases = h_alias_ptr; |
167 | (*h_addr_ptrs)[0] = (char *) host_addr; |
168 | (*h_addr_ptrs)[1] = NULL; |
169 | resbuf->h_addr_list = *h_addr_ptrs; |
170 | if (af == AF_INET && (_res.options & RES_USE_INET6)) |
171 | { |
172 | /* We need to change the IP v4 address into the |
173 | IP v6 address. */ |
174 | char tmp[INADDRSZ]; |
175 | char *p = (char *) host_addr; |
176 | int i; |
177 | |
178 | /* Save a copy of the IP v4 address. */ |
179 | memcpy (tmp, host_addr, INADDRSZ); |
180 | /* Mark this ipv6 addr as a mapped ipv4. */ |
181 | for (i = 0; i < 10; i++) |
182 | *p++ = 0x00; |
183 | *p++ = 0xff; |
184 | *p++ = 0xff; |
185 | /* Copy the IP v4 address. */ |
186 | memcpy (p, tmp, INADDRSZ); |
187 | resbuf->h_addrtype = AF_INET6; |
188 | resbuf->h_length = IN6ADDRSZ; |
189 | } |
190 | else |
191 | { |
192 | resbuf->h_addrtype = af; |
193 | resbuf->h_length = addr_size; |
194 | } |
195 | if (h_errnop != NULL) |
196 | *h_errnop = NETDB_SUCCESS; |
197 | if (buffer_size == NULL) |
198 | *status = NSS_STATUS_SUCCESS; |
199 | else |
200 | *result = resbuf; |
201 | goto done; |
202 | } |
203 | |
204 | if (!isdigit (*cp) && *cp != '.') |
205 | break; |
206 | } |
207 | } |
208 | |
209 | if ((isxdigit (name[0]) && strchr (name, ':') != NULL) || name[0] == ':') |
210 | { |
211 | switch (af) |
212 | { |
213 | default: |
214 | af = (_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET; |
215 | if (af == AF_INET6) |
216 | { |
217 | addr_size = IN6ADDRSZ; |
218 | break; |
219 | } |
220 | /* FALLTHROUGH */ |
221 | |
222 | case AF_INET: |
223 | /* This is not possible. We cannot represent an IPv6 address |
224 | in an `struct in_addr' variable. */ |
225 | *h_errnop = HOST_NOT_FOUND; |
226 | if (buffer_size == NULL) |
227 | *status = NSS_STATUS_NOTFOUND; |
228 | else |
229 | *result = NULL; |
230 | goto done; |
231 | |
232 | case AF_INET6: |
233 | addr_size = IN6ADDRSZ; |
234 | break; |
235 | } |
236 | |
237 | for (cp = name;; ++cp) |
238 | { |
239 | if (!*cp) |
240 | { |
241 | if (*--cp == '.') |
242 | break; |
243 | |
244 | /* All-IPv6-legal, no dot at the end. Fake up a |
245 | hostent as if we'd actually done a lookup. */ |
246 | if (inet_pton (AF_INET6, name, host_addr) <= 0) |
247 | { |
248 | *h_errnop = HOST_NOT_FOUND; |
249 | if (buffer_size == NULL) |
250 | *status = NSS_STATUS_NOTFOUND; |
251 | else |
252 | *result = NULL; |
253 | goto done; |
254 | } |
255 | |
256 | resbuf->h_name = strcpy (hostname, name); |
257 | h_alias_ptr[0] = NULL; |
258 | resbuf->h_aliases = h_alias_ptr; |
259 | (*h_addr_ptrs)[0] = (char *) host_addr; |
260 | (*h_addr_ptrs)[1] = (char *) 0; |
261 | resbuf->h_addr_list = *h_addr_ptrs; |
262 | resbuf->h_addrtype = AF_INET6; |
263 | resbuf->h_length = addr_size; |
264 | *h_errnop = NETDB_SUCCESS; |
265 | if (buffer_size == NULL) |
266 | *status = NSS_STATUS_SUCCESS; |
267 | else |
268 | *result = resbuf; |
269 | goto done; |
270 | } |
271 | |
272 | if (!isxdigit (*cp) && *cp != ':' && *cp != '.') |
273 | break; |
274 | } |
275 | } |
276 | } |
277 | |
278 | return 0; |
279 | |
280 | done: |
281 | return 1; |
282 | } |
283 | libc_hidden_def (__nss_hostname_digits_dots) |
284 | |