1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182
|
/* Copyright (C) 1996-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <assert.h>
#include <errno.h>
#include <libc-lock.h>
#include <stdlib.h>
#include <resolv.h>
#include <set-freeres.h>
#include "nsswitch.h"
/*******************************************************************\
|* Here we assume several symbols to be defined: *|
|* *|
|* LOOKUP_TYPE - the return type of the function *|
|* *|
|* FUNCTION_NAME - name of the non-reentrant function *|
|* *|
|* DATABASE_NAME - name of the database the function accesses *|
|* (e.g., host, services, ...) *|
|* *|
|* ADD_PARAMS - additional parameter, can vary in number *|
|* *|
|* ADD_VARIABLES - names of additional parameter *|
|* *|
|* BUFLEN - length of buffer allocated for the non *|
|* reentrant version *|
|* *|
|* Optionally the following vars can be defined: *|
|* *|
|* NEED_H_ERRNO - an extra parameter will be passed to point to *|
|* the global `h_errno' variable. *|
|* *|
\*******************************************************************/
#ifdef HANDLE_DIGITS_DOTS
# include <resolv/resolv_context.h>
#endif
/* To make the real sources a bit prettier. */
#define REENTRANT_NAME APPEND_R (FUNCTION_NAME)
#define APPEND_R(name) APPEND_R1 (name)
#define APPEND_R1(name) name##_r
#define INTERNAL(name) INTERNAL1 (name)
#define INTERNAL1(name) __##name
#define APPEND_FREEMEM_NAME1(name) __libc_##name##_freemem_ptr
#define APPEND_FREEMEM_NAME(name) APPEND_FREEMEM_NAME1(name)
#define FREEMEM_NAME APPEND_FREEMEM_NAME (FUNCTION_NAME)
/* Sometimes we need to store error codes in the `h_errno' variable. */
#ifdef NEED_H_ERRNO
# define H_ERRNO_PARM , int *h_errnop
# define H_ERRNO_VAR , &h_errno_tmp
# define H_ERRNO_VAR_P &h_errno_tmp
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR
# define H_ERRNO_VAR_P NULL
#endif
#ifdef HAVE_AF
# define AF_VAL af
#else
# define AF_VAL AF_INET
#endif
/* Prototype for reentrant version we use here. */
extern int INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf,
char *buffer, size_t buflen,
LOOKUP_TYPE **result H_ERRNO_PARM)
attribute_hidden;
/* We need to protect the dynamic buffer handling. */
__libc_lock_define_initialized (static, lock);
/* This points to the static buffer used. */
static char *buffer;
weak_alias (buffer, FREEMEM_NAME)
LOOKUP_TYPE *
FUNCTION_NAME (ADD_PARAMS)
{
static size_t buffer_size;
static LOOKUP_TYPE resbuf;
LOOKUP_TYPE *result;
#ifdef NEED_H_ERRNO
int h_errno_tmp = 0;
#endif
#ifdef HANDLE_DIGITS_DOTS
/* Wrap both __nss_hostname_digits_dots and the actual lookup
function call in the same context. */
struct resolv_context *res_ctx = __resolv_context_get ();
if (res_ctx == NULL)
{
# if NEED_H_ERRNO
__set_h_errno (NETDB_INTERNAL);
# endif
return NULL;
}
#endif
/* Get lock. */
__libc_lock_lock (lock);
if (buffer == NULL)
{
buffer_size = BUFLEN;
buffer = (char *) malloc (buffer_size);
}
#ifdef HANDLE_DIGITS_DOTS
if (buffer != NULL)
{
if (__nss_hostname_digits_dots_context
(res_ctx, name, &resbuf, &buffer, &buffer_size, 0, &result, NULL,
AF_VAL, H_ERRNO_VAR_P))
goto done;
}
#endif
while (buffer != NULL
&& (INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, &resbuf, buffer,
buffer_size, &result H_ERRNO_VAR)
== ERANGE)
#ifdef NEED_H_ERRNO
&& h_errno_tmp == NETDB_INTERNAL
#endif
)
{
char *new_buf;
buffer_size *= 2;
new_buf = (char *) realloc (buffer, buffer_size);
if (new_buf == NULL)
{
/* We are out of memory. Free the current buffer so that the
process gets a chance for a normal termination. */
free (buffer);
__set_errno (ENOMEM);
}
buffer = new_buf;
}
if (buffer == NULL)
result = NULL;
#ifdef HANDLE_DIGITS_DOTS
done:
#endif
/* Release lock. */
__libc_lock_unlock (lock);
#ifdef HANDLE_DIGITS_DOTS
__resolv_context_put (res_ctx);
#endif
#ifdef NEED_H_ERRNO
if (h_errno_tmp != 0)
__set_h_errno (h_errno_tmp);
#endif
return result;
}
nss_interface_function (FUNCTION_NAME)
|