1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
|
/* Hosts file parser in nss_files module.
Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <assert.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv.h>
/* Get implementation for some internal functions. */
#include "../resolv/mapv4v6addr.h"
#include "../resolv/res_hconf.h"
#define ENTNAME hostent
#define DATABASE "hosts"
#define NEED_H_ERRNO
#define EXTRA_ARGS , af, flags
#define EXTRA_ARGS_DECL , int af, int flags
#define ENTDATA hostent_data
struct hostent_data
{
unsigned char host_addr[16]; /* IPv4 or IPv6 address. */
char *h_addr_ptrs[2]; /* Points to that and null terminator. */
};
#define TRAILING_LIST_MEMBER h_aliases
#define TRAILING_LIST_SEPARATOR_P isspace
#include "files-parse.c"
LINE_PARSER
("#",
{
char *addr;
STRING_FIELD (addr, isspace, 1);
/* Parse address. */
if (inet_pton (af, addr, entdata->host_addr) <= 0
&& (af != AF_INET6 || (flags & AI_V4MAPPED) == 0
|| inet_pton (AF_INET, addr, entdata->host_addr) <= 0
|| (map_v4v6_address ((char *) entdata->host_addr,
(char *) entdata->host_addr),
0)))
/* Illegal address: ignore line. */
return 0;
/* We always return entries of the requested form. */
result->h_addrtype = af;
result->h_length = af == AF_INET ? INADDRSZ : IN6ADDRSZ;
/* Store a pointer to the address in the expected form. */
entdata->h_addr_ptrs[0] = entdata->host_addr;
entdata->h_addr_ptrs[1] = NULL;
result->h_addr_list = entdata->h_addr_ptrs;
STRING_FIELD (result->h_name, isspace, 1);
})
#define HOST_DB_LOOKUP(name, keysize, keypattern, break_if_match, proto...) \
enum nss_status \
_nss_files_get##name##_r (proto, \
struct STRUCTURE *result, char *buffer, \
size_t buflen, int *errnop H_ERRNO_PROTO) \
{ \
enum nss_status status; \
\
__libc_lock_lock (lock); \
\
/* Reset file pointer to beginning or open file. */ \
status = internal_setent (keep_stream); \
\
if (status == NSS_STATUS_SUCCESS) \
{ \
/* Tell getent function that we have repositioned the file pointer. */ \
last_use = getby; \
\
while ((status = internal_getent (result, buffer, buflen, errnop \
H_ERRNO_ARG EXTRA_ARGS_VALUE)) \
== NSS_STATUS_SUCCESS) \
{ break_if_match } \
\
if (status == NSS_STATUS_SUCCESS \
&& _res_hconf.flags & HCONF_FLAG_MULTI) \
{ \
/* We have to get all host entries from the file. */ \
const size_t tmp_buflen = MIN (buflen, 4096); \
char tmp_buffer[tmp_buflen]; \
struct hostent tmp_result_buf; \
int naddrs = 1; \
int naliases = 0; \
char *bufferend; \
\
while (result->h_aliases[naliases] != NULL) \
++naliases; \
\
bufferend = (char *) &result->h_aliases[naliases + 1]; \
\
while ((status = internal_getent (&tmp_result_buf, tmp_buffer, \
tmp_buflen, errnop H_ERRNO_ARG \
EXTRA_ARGS_VALUE)) \
== NSS_STATUS_SUCCESS) \
{ \
int matches = 1; \
struct hostent *old_result = result; \
result = &tmp_result_buf; \
/* The following piece is a bit clumsy but we want to use the \
`break_if_match' value. The optimizer should do its \
job. */ \
do \
{ \
break_if_match \
result = old_result; \
} \
while ((matches = 0)); \
\
if (matches) \
{ \
/* We could be very clever and try to recycle a few bytes \
in the buffer instead of generating new arrays. But \
we are not doing this here since it's more work than \
it's worth. Simply let the user provide a bit bigger \
buffer. */ \
char **new_h_addr_list; \
char **new_h_aliases; \
int newaliases = 0; \
size_t newstrlen = 0; \
int cnt; \
\
/* Count the new aliases and the length of the strings. */ \
while (tmp_result_buf.h_aliases[newaliases] != NULL) \
{ \
char *cp = tmp_result_buf.h_aliases[newaliases]; \
++newaliases; \
newstrlen += strlen (cp) + 1; \
} \
/* If the real name is different add it also to the \
aliases. This means that there is a duplication \
in the alias list but this is really the users \
problem. */ \
if (strcmp (old_result->h_name, \
tmp_result_buf.h_name) != 0) \
{ \
++newaliases; \
newstrlen += strlen (tmp_result_buf.h_name) + 1; \
} \
\
/* Now we can check whether the buffer is large enough. */ \
if (bufferend + 16 + (naddrs + 2) * sizeof (char *) \
+ roundup (newstrlen, sizeof (char *)) \
+ (naliases + newaliases + 1) * sizeof (char *) \
>= buffer + buflen) \
{ \
*errnop = ERANGE; \
*herrnop = NETDB_INTERNAL; \
status = NSS_STATUS_TRYAGAIN; \
break; \
} \
\
new_h_addr_list = \
(char **) (bufferend \
+ roundup (newstrlen, sizeof (char *)) \
+ 16); \
new_h_aliases = \
(char **) ((char *) new_h_addr_list \
+ (naddrs + 2) * sizeof (char *)); \
\
/* Copy the old data in the new arrays. */ \
for (cnt = 0; cnt < naddrs; ++cnt) \
new_h_addr_list[cnt] = old_result->h_addr_list[cnt]; \
\
for (cnt = 0; cnt < naliases; ++cnt) \
new_h_aliases[cnt] = old_result->h_aliases[cnt]; \
\
/* Store the new strings. */ \
cnt = 0; \
while (tmp_result_buf.h_aliases[cnt] != NULL) \
{ \
new_h_aliases[naliases++] = bufferend; \
bufferend = (__stpcpy (bufferend, \
tmp_result_buf.h_aliases[cnt]) \
+ 1); \
++cnt; \
} \
\
if (cnt < newaliases) \
{ \
new_h_aliases[naliases++] = bufferend; \
bufferend = __stpcpy (bufferend, \
tmp_result_buf.h_name) + 1; \
} \
\
/* Final NULL pointer. */ \
new_h_aliases[naliases] = NULL; \
\
/* Round up the buffer end address. */ \
bufferend += (sizeof (char *) \
- ((bufferend - (char *) 0) \
% sizeof (char *))); \
\
/* Now the new address. */ \
new_h_addr_list[naddrs++] = \
memcpy (bufferend, tmp_result_buf.h_addr, \
tmp_result_buf.h_length); \
\
/* Also here a final NULL pointer. */ \
new_h_addr_list[naddrs] = NULL; \
\
/* Store the new array pointers. */ \
old_result->h_aliases = new_h_aliases; \
old_result->h_addr_list = new_h_addr_list; \
\
/* Compute the new buffer end. */ \
bufferend = (char *) &new_h_aliases[naliases + 1]; \
assert (bufferend <= buffer + buflen); \
\
result = old_result; \
} \
} \
\
if (status != NSS_STATUS_TRYAGAIN) \
status = NSS_STATUS_SUCCESS; \
} \
\
\
if (! keep_stream) \
internal_endent (); \
} \
\
__libc_lock_unlock (lock); \
\
return status; \
}
#define EXTRA_ARGS_VALUE \
, ((_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET), \
((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0)
#include "files-XXX.c"
HOST_DB_LOOKUP (hostbyname, ,,
{
LOOKUP_NAME_CASE (h_name, h_aliases)
}, const char *name)
#undef EXTRA_ARGS_VALUE
/* XXX Is using _res to determine whether we want to convert IPv4 addresses
to IPv6 addresses really the right thing to do? */
#define EXTRA_ARGS_VALUE \
, af, ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0)
HOST_DB_LOOKUP (hostbyname2, ,,
{
LOOKUP_NAME_CASE (h_name, h_aliases)
}, const char *name, int af)
DB_LOOKUP (hostbyaddr, ,,
{
if (result->h_length == len
&& ! memcmp (addr, result->h_addr_list[0], len))
break;
}, const void *addr, socklen_t len, int af)
|
