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b43b13ac UD |
1 | /* |
2 | * Copyright (c) 1995-1999 by Internet Software Consortium. | |
3 | * | |
4 | * Permission to use, copy, modify, and distribute this software for any | |
5 | * purpose with or without fee is hereby granted, provided that the above | |
6 | * copyright notice and this permission notice appear in all copies. | |
7 | * | |
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS | |
9 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES | |
10 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE | |
11 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL | |
12 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR | |
13 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS | |
14 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS | |
15 | * SOFTWARE. | |
16 | */ | |
17 | ||
b43b13ac | 18 | #include <sys/types.h> |
b43b13ac | 19 | #include <netinet/in.h> |
b43b13ac | 20 | #include <arpa/nameser.h> |
b43b13ac | 21 | #include <resolv.h> |
b43b13ac | 22 | |
b43b13ac | 23 | |
e685e07d UD |
24 | /* The following bit is copied from res_data.c (where it is #ifdef'ed |
25 | out) since res_init() should go into libc.so but the rest of that | |
26 | file should not. */ | |
b43b13ac UD |
27 | |
28 | int | |
29 | res_init(void) { | |
30 | extern int __res_vinit(res_state, int); | |
31 | ||
32 | /* | |
33 | * These three fields used to be statically initialized. This made | |
34 | * it hard to use this code in a shared library. It is necessary, | |
35 | * now that we're doing dynamic initialization here, that we preserve | |
36 | * the old semantics: if an application modifies one of these three | |
37 | * fields of _res before res_init() is called, res_init() will not | |
38 | * alter them. Of course, if an application is setting them to | |
39 | * _zero_ before calling res_init(), hoping to override what used | |
40 | * to be the static default, we can't detect it and unexpected results | |
41 | * will follow. Zero for any of these fields would make no sense, | |
42 | * so one can safely assume that the applications were already getting | |
43 | * unexpected results. | |
44 | * | |
45 | * _res.options is tricky since some apps were known to diddle the bits | |
46 | * before res_init() was first called. We can't replicate that semantic | |
47 | * with dynamic initialization (they may have turned bits off that are | |
48 | * set in RES_DEFAULT). Our solution is to declare such applications | |
49 | * "broken". They could fool us by setting RES_INIT but none do (yet). | |
50 | */ | |
51 | if (!_res.retrans) | |
52 | _res.retrans = RES_TIMEOUT; | |
53 | if (!_res.retry) | |
54 | _res.retry = 4; | |
55 | if (!(_res.options & RES_INIT)) | |
56 | _res.options = RES_DEFAULT; | |
2ed2dc18 UD |
57 | else if (_res.nscount > 0) { |
58 | __res_nclose (&_res); /* Close any VC sockets. */ | |
59 | ||
60 | for (int ns = 0; ns < MAXNS; ns++) { | |
61 | free (_res._u._ext.nsaddrs[ns]); | |
62 | _res._u._ext.nsaddrs[ns] = NULL; | |
63 | } | |
64 | } | |
b43b13ac UD |
65 | |
66 | /* | |
67 | * This one used to initialize implicitly to zero, so unless the app | |
68 | * has set it to something in particular, we can randomize it now. | |
69 | */ | |
70 | if (!_res.id) | |
71 | _res.id = res_randomid(); | |
72 | ||
73 | return (__res_vinit(&_res, 1)); | |
74 | } | |
e685e07d | 75 | \f |
4aeb650e RM |
76 | /* This needs to be after the use of _res in res_init, above. */ |
77 | #undef _res | |
78 | ||
1f503475 UD |
79 | /* The resolver state for use by single-threaded programs. |
80 | This differs from plain `struct __res_state _res;' in that it doesn't | |
81 | create a common definition, but a plain symbol that resides in .bss, | |
82 | which can have an alias. */ | |
83 | struct __res_state _res __attribute__((section (".bss"))); | |
4aeb650e | 84 | |
0e9d6240 UD |
85 | #include <tls.h> |
86 | ||
87 | #if USE___THREAD | |
88 | #undef __resp | |
89 | __thread struct __res_state *__resp = &_res; | |
90 | extern __thread struct __res_state *__libc_resp | |
91 | __attribute__ ((alias ("__resp"))) attribute_hidden; | |
92 | #endif | |
93 | ||
4aeb650e RM |
94 | /* We declare this with compat_symbol so that it's not |
95 | visible at link time. Programs must use the accessor functions. */ | |
0e9d6240 UD |
96 | #if defined HAVE_ELF && defined SHARED && defined DO_VERSIONING |
97 | # include <shlib-compat.h> | |
4aeb650e | 98 | compat_symbol (libc, _res, _res, GLIBC_2_0); |
4aeb650e | 99 | #endif |
b43b13ac | 100 | |
e685e07d | 101 | #include <shlib-compat.h> |
66ac0abe | 102 | |
e685e07d UD |
103 | #if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_2) |
104 | # undef res_init | |
1cb990bc | 105 | extern int __res_init_weak (void); |
0e3af135 | 106 | weak_extern (__res_init_weak); |
1cb990bc | 107 | strong_alias (__res_init, __res_init_weak); |
0e3af135 | 108 | compat_symbol (libc, __res_init_weak, res_init, GLIBC_2_0); |
e685e07d | 109 | #endif |