1 /*
2 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6 #include <port_before.h>
7 #include <thread.h>
8 #include <errno.h>
9 #include <netdb.h>
10 #include <malloc.h>
11 #include <string.h>
12 #include <resolv_mt.h>
13 #include <irs.h>
14 #include <port_after.h>
15
16 /*
17 * much of the original version of sunw_mtxtxres.c was incorporated into
18 * ISC libbind as resolv/mtctxres.c. The following bits have not yet made
19 * it into ISC libbind.
20 */
21
22 /*
23 * There used to be a private, MT-safe resolver interface that used TSD
24 * to store per-thread _res, h_errno, etc. We continue to provide the
25 * access functions __res_get_res() and __res_get_h_errno() so that binaries
26 * that used the private interface will continue to work.
27 */
28
29 #ifdef _res
30 #undef _res
31 #endif
32
33 extern struct __res_state *__res_state(void);
34
35 struct __res_state *
__res_get_res(void)36 __res_get_res(void) {
37 return (__res_state());
38 }
39
40
41 #ifdef h_errno
42 #undef h_errno
43 #endif
44
45 extern int *__h_errno(void);
46
47 int *
__res_get_h_errno(void)48 __res_get_h_errno(void) {
49 return (__h_errno());
50 }
51
52
53 #ifdef SUNW_HOSTS_FALLBACK
54
55 /*
56 * When the name service switch calls libresolv, it doesn't want fallback
57 * to /etc/hosts, so we provide a method to turn it off.
58 */
59
60 void
__res_set_no_hosts_fallback(void)61 __res_set_no_hosts_fallback(void) {
62 ___mtctxres()->no_hosts_fallback_private = 1;
63 }
64
65 void
__res_unset_no_hosts_fallback(void)66 __res_unset_no_hosts_fallback(void) {
67 ___mtctxres()->no_hosts_fallback_private = 0;
68 }
69
70 int
__res_no_hosts_fallback(void)71 __res_no_hosts_fallback(void) {
72 return (___mtctxres()->no_hosts_fallback_private);
73 }
74
75 #endif /* SUNW_HOSTS_FALLBACK */
76
77 #ifdef SUNW_OVERRIDE_RETRY
78
79 /*
80 * The NS switch wants to be able to override the number of retries.
81 */
82
83 int
__res_override_retry(int retry)84 __res_override_retry(int retry) {
85 ___mtctxres()->retry_private = retry;
86 /*
87 * This function doesn't really need a return value; saving the
88 * old retry setting, and restoring it, is handled by __res_retry()
89 * and __res_retry_reset() below. However, the nss_dns library
90 * must have a private version of this function to be used when
91 * running with an old libresolv. That private nss_dns function
92 * needs a return value, and a function pointer is used to select
93 * the right function at runtime. Thus, __res_override_retry
94 * must have a function prototype consistent with the private
95 * nss_dns function, i.e., one that returns an int.
96 *
97 * Given that we do have a return value, that value must be zero.
98 * That's because retry_private == 0 is used to indicate that
99 * no override retry value is in effect, and the way we expect
100 * nss_dns to call us is:
101 *
102 * int oldretry = __res_override_retry(N);
103 * <whatever>
104 * (void)__res_override_retry(old_retry);
105 */
106 return (0);
107 }
108
109 int
__res_retry(int retry)110 __res_retry(int retry) {
111 mtctxres_t *mt = ___mtctxres();
112
113 mt->retry_save = retry;
114 return ((mt->retry_private != 0) ? mt->retry_private : retry);
115 }
116
117 int
__res_retry_reset(void)118 __res_retry_reset(void) {
119 mtctxres_t *mt = ___mtctxres();
120
121 return (mt->retry_save);
122 }
123
124 #endif /* SUNW_OVERRIDE_RETRY */
125