glibc/hesiod/nss_hesiod/hesiod-proto.c
Florian Weimer 5018f16c62 hesiod: Always use thread-local resolver state [BZ #19573]
The Hesiod implementation imported into glibc was enhanced
to support caller-supplied resolver states.  But its only
consumer is nss_hesiod, and it supplies the thread-local
resolver state.  Therefore, this commit changes the Hesiod
implementation to use the thread-local resolver state (_res)
directly.  This fixes bug 19573 because the Hesiod
implementation no longer has to initialize and free any
resolver state.

To avoid any risk of interposition of ABI-incompatible Hesiod
function implementations, this commit marks the Hesiod functions
as hidden.  (They were already hidden using a linker version
script.)
2016-05-02 15:25:20 +02:00

143 lines
3.5 KiB
C

/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
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
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <hesiod.h>
#include <netdb.h>
#include <netinet/in.h>
#include <nss.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* Declare a parser for Hesiod protocol entries. Although the format
of the entries is identical to those in /etc/protocols, here is no
predefined parser for us to use. */
#define ENTNAME protoent
struct protoent_data {};
#define TRAILING_LIST_MEMBER p_aliases
#define TRAILING_LIST_SEPARATOR_P isspace
#include <nss/nss_files/files-parse.c>
LINE_PARSER
("#",
STRING_FIELD (result->p_name, isspace, 1);
INT_FIELD (result->p_proto, isspace, 1, 10,);
)
enum nss_status
_nss_hesiod_setprotoent (int stayopen)
{
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_hesiod_endprotoent (void)
{
return NSS_STATUS_SUCCESS;
}
static enum nss_status
lookup (const char *name, const char *type, struct protoent *proto,
char *buffer, size_t buflen, int *errnop)
{
struct parser_data *data = (void *) buffer;
size_t linebuflen;
void *context;
char **list, **item;
int parse_res;
int found;
int olderr = errno;
if (hesiod_init (&context) < 0)
return NSS_STATUS_UNAVAIL;
list = hesiod_resolve (context, name, type);
if (list == NULL)
{
int err = errno;
hesiod_end (context);
__set_errno (olderr);
return err == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;
}
linebuflen = buffer + buflen - data->linebuffer;
item = list;
found = 0;
do
{
size_t len = strlen (*item) + 1;
if (linebuflen < len)
{
hesiod_free_list (context, list);
hesiod_end (context);
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
memcpy (data->linebuffer, *item, len);
parse_res = parse_line (buffer, proto, data, buflen, errnop);
if (parse_res == -1)
{
hesiod_free_list (context, list);
hesiod_end (context);
return NSS_STATUS_TRYAGAIN;
}
if (parse_res > 0)
found = 1;
++item;
}
while (*item != NULL && !found);
hesiod_free_list (context, list);
hesiod_end (context);
if (found == 0)
{
__set_errno (olderr);
return NSS_STATUS_NOTFOUND;
}
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_hesiod_getprotobyname_r (const char *name, struct protoent *proto,
char *buffer, size_t buflen, int *errnop)
{
return lookup (name, "protocol", proto, buffer, buflen, errnop);
}
enum nss_status
_nss_hesiod_getprotobynumber_r (const int protocol, struct protoent *proto,
char *buffer, size_t buflen, int *errnop)
{
char protostr[21];
snprintf (protostr, sizeof protostr, "%d", protocol);
return lookup (protostr, "protonum", proto, buffer, buflen, errnop);
}