| 1 | /* Copyright (C) 1996-2002, 2003, 2004 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, write to the Free |
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| 17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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| 18 | 02111-1307 USA. */ |
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| 19 | |
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| 20 | #include <assert.h> |
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| 21 | #include <errno.h> |
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| 22 | #include <stdbool.h> |
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| 23 | #include "nsswitch.h" |
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| 24 | #ifdef USE_NSCD |
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| 25 | # include <nscd/nscd_proto.h> |
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| 26 | #endif |
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| 27 | #ifdef NEED__RES_HCONF |
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| 28 | # include "res_hconf.h" |
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| 29 | #endif |
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| 30 | #ifdef NEED__RES |
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| 31 | # include <resolv.h> |
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| 32 | #endif |
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| 33 | /*******************************************************************\ |
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| 34 | |* Here we assume several symbols to be defined: *| |
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| 35 | |* *| |
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| 36 | |* LOOKUP_TYPE - the return type of the function *| |
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| 37 | |* *| |
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| 38 | |* FUNCTION_NAME - name of the non-reentrant function *| |
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| 39 | |* *| |
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| 40 | |* DATABASE_NAME - name of the database the function accesses *| |
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| 41 | |* (e.g., host, services, ...) *| |
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| 42 | |* *| |
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| 43 | |* ADD_PARAMS - additional parameter, can vary in number *| |
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| 44 | |* *| |
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| 45 | |* ADD_VARIABLES - names of additional parameter *| |
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| 46 | |* *| |
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| 47 | |* Optionally the following vars can be defined: *| |
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| 48 | |* *| |
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| 49 | |* NEED_H_ERRNO - an extra parameter will be passed to point to *| |
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| 50 | |* the global `h_errno' variable. *| |
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| 51 | |* *| |
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| 52 | |* NEED__RES - the global _res variable might be used so we *| |
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| 53 | |* will have to initialize it if necessary *| |
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| 54 | |* *| |
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| 55 | |* PREPROCESS - code run before anything else *| |
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| 56 | |* *| |
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| 57 | |* POSTPROCESS - code run after the lookup *| |
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| 58 | |* *| |
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| 59 | \*******************************************************************/ |
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| 60 | |
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| 61 | /* To make the real sources a bit prettier. */ |
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| 62 | #define REENTRANT_NAME APPEND_R (FUNCTION_NAME) |
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| 63 | #define APPEND_R(name) APPEND_R1 (name) |
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| 64 | #define APPEND_R1(name) name##_r |
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| 65 | #define INTERNAL(name) INTERNAL1 (name) |
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| 66 | #define INTERNAL1(name) __##name |
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| 67 | #define NEW(name) NEW1 (name) |
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| 68 | #define NEW1(name) __new_##name |
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| 69 | |
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| 70 | #ifdef USE_NSCD |
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| 71 | # define NSCD_NAME ADD_NSCD (REENTRANT_NAME) |
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| 72 | # define ADD_NSCD(name) ADD_NSCD1 (name) |
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| 73 | # define ADD_NSCD1(name) __nscd_##name |
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| 74 | # define NOT_USENSCD_NAME ADD_NOT_NSCDUSE (DATABASE_NAME) |
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| 75 | # define ADD_NOT_NSCDUSE(name) ADD_NOT_NSCDUSE1 (name) |
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| 76 | # define ADD_NOT_NSCDUSE1(name) __nss_not_use_nscd_##name |
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| 77 | #endif |
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| 78 | |
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| 79 | #define FUNCTION_NAME_STRING STRINGIZE (FUNCTION_NAME) |
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| 80 | #define REENTRANT_NAME_STRING STRINGIZE (REENTRANT_NAME) |
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| 81 | #define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME) |
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| 82 | #define STRINGIZE(name) STRINGIZE1 (name) |
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| 83 | #define STRINGIZE1(name) #name |
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| 84 | |
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| 85 | #ifndef DB_LOOKUP_FCT |
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| 86 | # define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup) |
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| 87 | # define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post) |
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| 88 | # define CONCAT3_2(Pre, Name, Post) Pre##Name##Post |
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| 89 | #endif |
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| 90 | |
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| 91 | /* Sometimes we need to store error codes in the `h_errno' variable. */ |
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| 92 | #ifdef NEED_H_ERRNO |
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| 93 | # define H_ERRNO_PARM , int *h_errnop |
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| 94 | # define H_ERRNO_VAR , h_errnop |
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| 95 | # define H_ERRNO_VAR_P h_errnop |
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| 96 | #else |
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| 97 | # define H_ERRNO_PARM |
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| 98 | # define H_ERRNO_VAR |
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| 99 | # define H_ERRNO_VAR_P NULL |
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| 100 | #endif |
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| 101 | |
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| 102 | #ifdef HAVE_AF |
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| 103 | # define AF_VAL af |
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| 104 | #else |
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| 105 | # define AF_VAL AF_INET |
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| 106 | #endif |
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| 107 | |
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| 108 | /* Type of the lookup function we need here. */ |
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| 109 | typedef enum nss_status (*lookup_function) (ADD_PARAMS, LOOKUP_TYPE *, char *, |
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| 110 | size_t, int * H_ERRNO_PARM); |
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| 111 | |
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| 112 | /* The lookup function for the first entry of this service. */ |
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| 113 | extern int DB_LOOKUP_FCT (service_user **nip, const char *name, void **fctp) |
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| 114 | internal_function; |
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| 115 | libc_hidden_proto (DB_LOOKUP_FCT) |
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| 116 | |
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| 117 | |
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| 118 | int |
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| 119 | INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer, |
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| 120 | size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM) |
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| 121 | { |
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| 122 | static service_user *startp; |
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| 123 | static lookup_function start_fct; |
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| 124 | service_user *nip; |
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| 125 | union |
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| 126 | { |
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| 127 | lookup_function l; |
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| 128 | void *ptr; |
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| 129 | } fct; |
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| 130 | |
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| 131 | int no_more; |
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| 132 | enum nss_status status = NSS_STATUS_UNAVAIL; |
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| 133 | #ifdef USE_NSCD |
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| 134 | int nscd_status; |
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| 135 | #endif |
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| 136 | #ifdef NEED_H_ERRNO |
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| 137 | bool any_service = false; |
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| 138 | #endif |
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| 139 | |
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| 140 | #ifdef PREPROCESS |
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| 141 | PREPROCESS; |
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| 142 | #endif |
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| 143 | |
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| 144 | #ifdef HANDLE_DIGITS_DOTS |
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| 145 | switch (__nss_hostname_digits_dots (name, resbuf, &buffer, NULL, |
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| 146 | buflen, result, &status, AF_VAL, |
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| 147 | H_ERRNO_VAR_P)) |
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| 148 | { |
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| 149 | case -1: |
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| 150 | return errno; |
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| 151 | case 1: |
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| 152 | goto done; |
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| 153 | } |
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| 154 | #endif |
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| 155 | |
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| 156 | #ifdef USE_NSCD |
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| 157 | if (NOT_USENSCD_NAME > 0 && ++NOT_USENSCD_NAME > NSS_NSCD_RETRY) |
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| 158 | NOT_USENSCD_NAME = 0; |
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| 159 | |
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| 160 | if (!NOT_USENSCD_NAME) |
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| 161 | { |
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| 162 | nscd_status = NSCD_NAME (ADD_VARIABLES, resbuf, buffer, buflen, result |
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| 163 | H_ERRNO_VAR); |
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| 164 | if (nscd_status >= 0) |
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| 165 | return nscd_status; |
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| 166 | } |
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| 167 | #endif |
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| 168 | |
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| 169 | if (startp == NULL) |
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| 170 | { |
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| 171 | no_more = DB_LOOKUP_FCT (&nip, REENTRANT_NAME_STRING, &fct.ptr); |
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| 172 | if (no_more) |
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| 173 | startp = (service_user *) -1l; |
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| 174 | else |
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| 175 | { |
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| 176 | startp = nip; |
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| 177 | start_fct = fct.l; |
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| 178 | |
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| 179 | #ifdef NEED__RES |
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| 180 | /* The resolver code will really be used so we have to |
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| 181 | initialize it. */ |
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| 182 | if (__res_maybe_init (&_res, 0) == -1) |
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| 183 | { |
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| 184 | *h_errnop = NETDB_INTERNAL; |
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| 185 | *result = NULL; |
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| 186 | return errno; |
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| 187 | } |
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| 188 | #endif /* need _res */ |
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| 189 | #ifdef NEED__RES_HCONF |
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| 190 | if (!_res_hconf.initialized) |
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| 191 | _res_hconf_init (); |
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| 192 | #endif /* need _res_hconf */ |
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| 193 | } |
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| 194 | } |
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| 195 | else |
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| 196 | { |
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| 197 | fct.l = start_fct; |
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| 198 | no_more = (nip = startp) == (service_user *) -1l; |
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| 199 | } |
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| 200 | |
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| 201 | while (no_more == 0) |
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| 202 | { |
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| 203 | #ifdef NEED_H_ERRNO |
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| 204 | any_service = true; |
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| 205 | #endif |
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| 206 | |
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| 207 | status = DL_CALL_FCT (fct.l, (ADD_VARIABLES, resbuf, buffer, buflen, |
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| 208 | &errno H_ERRNO_VAR)); |
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| 209 | |
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| 210 | /* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the |
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| 211 | provided buffer is too small. In this case we should give |
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| 212 | the user the possibility to enlarge the buffer and we should |
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| 213 | not simply go on with the next service (even if the TRYAGAIN |
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| 214 | action tells us so). */ |
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| 215 | if (status == NSS_STATUS_TRYAGAIN |
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| 216 | #ifdef NEED_H_ERRNO |
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| 217 | && *h_errnop == NETDB_INTERNAL |
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| 218 | #endif |
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| 219 | && errno == ERANGE) |
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| 220 | break; |
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| 221 | |
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| 222 | no_more = __nss_next (&nip, REENTRANT_NAME_STRING, |
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| 223 | &fct.ptr, status, 0); |
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| 224 | } |
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| 225 | |
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| 226 | #ifdef HANDLE_DIGITS_DOTS |
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| 227 | done: |
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| 228 | #endif |
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| 229 | *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL; |
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| 230 | #ifdef NEED_H_ERRNO |
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| 231 | if (status != NSS_STATUS_SUCCESS && ! any_service) |
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| 232 | /* We were not able to use any service. */ |
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| 233 | *h_errnop = NO_RECOVERY; |
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| 234 | #endif |
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| 235 | #ifdef POSTPROCESS |
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| 236 | POSTPROCESS; |
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| 237 | #endif |
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| 238 | |
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| 239 | int res; |
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| 240 | if (status == NSS_STATUS_SUCCESS || status == NSS_STATUS_NOTFOUND) |
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| 241 | res = 0; |
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| 242 | /* Don't pass back ERANGE if this is not for a too-small buffer. */ |
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| 243 | else if (errno == ERANGE && status != NSS_STATUS_TRYAGAIN) |
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| 244 | res = EINVAL; |
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| 245 | #ifdef NEED_H_ERRNO |
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| 246 | /* These functions only set errno if h_errno is NETDB_INTERNAL. */ |
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| 247 | else if (status == NSS_STATUS_TRYAGAIN && *h_errnop != NETDB_INTERNAL) |
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| 248 | res = EAGAIN; |
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| 249 | #endif |
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| 250 | else |
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| 251 | return errno; |
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| 252 | |
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| 253 | __set_errno (res); |
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| 254 | return res; |
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| 255 | } |
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| 256 | |
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| 257 | |
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| 258 | #include <shlib-compat.h> |
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| 259 | #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2) |
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| 260 | #define OLD(name) OLD1 (name) |
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| 261 | #define OLD1(name) __old_##name |
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| 262 | |
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| 263 | int |
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| 264 | attribute_compat_text_section |
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| 265 | OLD (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer, |
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| 266 | size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM) |
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| 267 | { |
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| 268 | int ret = INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, resbuf, buffer, |
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| 269 | buflen, result H_ERRNO_VAR); |
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| 270 | |
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| 271 | if (ret != 0 || result == NULL) |
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| 272 | ret = -1; |
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| 273 | |
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| 274 | return ret; |
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| 275 | } |
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| 276 | |
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| 277 | #define do_symbol_version(real, name, version) \ |
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| 278 | compat_symbol (libc, real, name, version) |
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| 279 | do_symbol_version (OLD (REENTRANT_NAME), REENTRANT_NAME, GLIBC_2_0); |
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| 280 | #endif |
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| 281 | |
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| 282 | /* As INTERNAL (REENTRANT_NAME) may be hidden, we need an alias |
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| 283 | in between so that the REENTRANT_NAME@@GLIBC_2.1.2 is not |
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| 284 | hidden too. */ |
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| 285 | strong_alias (INTERNAL (REENTRANT_NAME), NEW (REENTRANT_NAME)); |
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| 286 | |
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| 287 | #define do_default_symbol_version(real, name, version) \ |
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| 288 | versioned_symbol (libc, real, name, version) |
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| 289 | do_default_symbol_version (NEW (REENTRANT_NAME), |
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| 290 | REENTRANT_NAME, GLIBC_2_1_2); |
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| 291 | |
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| 292 | static_link_warning (REENTRANT_NAME) |
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