1 | /* Copyright (C) 1996-2001,2003, 2004 Free Software Foundation, Inc. |
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2 | This file is part of the GNU C Library. |
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3 | |
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4 | The GNU C Library is free software; you can redistribute it and/or |
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5 | modify it under the terms of the GNU Lesser General Public |
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6 | License as published by the Free Software Foundation; either |
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7 | version 2.1 of the License, or (at your option) any later version. |
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8 | |
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9 | The GNU C Library is distributed in the hope that it will be useful, |
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10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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12 | Lesser General Public License for more details. |
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13 | |
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14 | You should have received a copy of the GNU Lesser General Public |
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15 | License along with the GNU C Library; if not, write to the Free |
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16 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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17 | 02111-1307 USA. */ |
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18 | |
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19 | #include <assert.h> |
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20 | #include <errno.h> |
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21 | #define _IO_MTSAFE_IO |
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22 | #include <bits/libc-lock.h> |
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23 | #include <stdlib.h> |
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24 | #include <resolv.h> |
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25 | |
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26 | #include "nsswitch.h" |
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27 | |
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28 | /*******************************************************************\ |
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29 | |* Here we assume several symbols to be defined: *| |
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30 | |* *| |
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31 | |* LOOKUP_TYPE - the return type of the function *| |
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32 | |* *| |
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33 | |* FUNCTION_NAME - name of the non-reentrant function *| |
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34 | |* *| |
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35 | |* DATABASE_NAME - name of the database the function accesses *| |
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36 | |* (e.g., host, services, ...) *| |
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37 | |* *| |
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38 | |* ADD_PARAMS - additional parameter, can vary in number *| |
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39 | |* *| |
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40 | |* ADD_VARIABLES - names of additional parameter *| |
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41 | |* *| |
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42 | |* BUFLEN - length of buffer allocated for the non *| |
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43 | |* reentrant version *| |
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44 | |* *| |
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45 | |* Optionally the following vars can be defined: *| |
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46 | |* *| |
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47 | |* NEED_H_ERRNO - an extra parameter will be passed to point to *| |
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48 | |* the global `h_errno' variable. *| |
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49 | |* *| |
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50 | \*******************************************************************/ |
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51 | |
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52 | /* To make the real sources a bit prettier. */ |
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53 | #define REENTRANT_NAME APPEND_R (FUNCTION_NAME) |
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54 | #define APPEND_R(name) APPEND_R1 (name) |
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55 | #define APPEND_R1(name) name##_r |
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56 | #define INTERNAL(name) INTERNAL1 (name) |
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57 | #define INTERNAL1(name) __##name |
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58 | |
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59 | /* Sometimes we need to store error codes in the `h_errno' variable. */ |
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60 | #ifdef NEED_H_ERRNO |
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61 | # define H_ERRNO_PARM , int *h_errnop |
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62 | # define H_ERRNO_VAR , &h_errno_tmp |
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63 | # define H_ERRNO_VAR_P &h_errno_tmp |
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64 | #else |
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65 | # define H_ERRNO_PARM |
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66 | # define H_ERRNO_VAR |
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67 | # define H_ERRNO_VAR_P NULL |
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68 | #endif |
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69 | |
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70 | #ifdef HAVE_AF |
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71 | # define AF_VAL af |
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72 | #else |
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73 | # define AF_VAL AF_INET |
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74 | #endif |
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75 | |
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76 | /* Prototype for reentrant version we use here. */ |
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77 | extern int INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, |
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78 | char *buffer, size_t buflen, |
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79 | LOOKUP_TYPE **result H_ERRNO_PARM); |
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80 | |
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81 | /* We need to protect the dynamic buffer handling. */ |
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82 | __libc_lock_define_initialized (static, lock); |
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83 | |
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84 | /* This points to the static buffer used. */ |
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85 | libc_freeres_ptr (static char *buffer); |
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86 | |
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87 | |
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88 | LOOKUP_TYPE * |
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89 | FUNCTION_NAME (ADD_PARAMS) |
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90 | { |
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91 | static size_t buffer_size; |
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92 | static LOOKUP_TYPE resbuf; |
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93 | LOOKUP_TYPE *result; |
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94 | #ifdef NEED_H_ERRNO |
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95 | int h_errno_tmp = 0; |
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96 | #endif |
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97 | |
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98 | /* Get lock. */ |
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99 | __libc_lock_lock (lock); |
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100 | |
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101 | if (buffer == NULL) |
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102 | { |
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103 | buffer_size = BUFLEN; |
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104 | buffer = (char *) malloc (buffer_size); |
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105 | } |
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106 | |
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107 | #ifdef HANDLE_DIGITS_DOTS |
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108 | if (buffer != NULL) |
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109 | { |
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110 | if (__nss_hostname_digits_dots (name, &resbuf, &buffer, |
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111 | &buffer_size, 0, &result, NULL, AF_VAL, |
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112 | H_ERRNO_VAR_P)) |
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113 | goto done; |
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114 | } |
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115 | #endif |
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116 | |
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117 | while (buffer != NULL |
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118 | && (INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, &resbuf, buffer, |
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119 | buffer_size, &result H_ERRNO_VAR) |
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120 | == ERANGE) |
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121 | #ifdef NEED_H_ERRNO |
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122 | && h_errno_tmp == NETDB_INTERNAL |
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123 | #endif |
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124 | ) |
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125 | { |
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126 | char *new_buf; |
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127 | buffer_size *= 2; |
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128 | new_buf = (char *) realloc (buffer, buffer_size); |
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129 | if (new_buf == NULL) |
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130 | { |
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131 | /* We are out of memory. Free the current buffer so that the |
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132 | process gets a chance for a normal termination. */ |
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133 | free (buffer); |
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134 | errno = (ENOMEM); |
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135 | } |
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136 | buffer = new_buf; |
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137 | } |
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138 | |
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139 | if (buffer == NULL) |
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140 | result = NULL; |
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141 | |
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142 | #ifdef HANDLE_DIGITS_DOTS |
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143 | done: |
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144 | #endif |
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145 | /* Release lock. */ |
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146 | __libc_lock_unlock (lock); |
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147 | |
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148 | #ifdef NEED_H_ERRNO |
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149 | if (h_errno_tmp != 0) |
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150 | h_errno = (h_errno_tmp); |
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151 | #endif |
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152 | |
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153 | return result; |
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154 | } |
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155 | |
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156 | static_link_warning (FUNCTION_NAME) |
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