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 * 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 * 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 61 __res_set_no_hosts_fallback(void) { 62 ___mtctxres()->no_hosts_fallback_private = 1; 63 } 64 65 void 66 __res_unset_no_hosts_fallback(void) { 67 ___mtctxres()->no_hosts_fallback_private = 0; 68 } 69 70 int 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 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 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 118 __res_retry_reset(void) { 119 mtctxres_t *mt = ___mtctxres(); 120 121 return (mt->retry_save); 122 } 123 124 #endif /* SUNW_OVERRIDE_RETRY */ 125