glibc/nis/nss_nis/nis-hosts.c

568 lines
14 KiB
C

/* Copyright (C) 1996-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@suse.de>, 1996.
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 <assert.h>
#include <nss.h>
#include <ctype.h>
/* The following is an ugly trick to avoid a prototype declaration for
_nss_nis_endgrent. */
#define _nss_nis_endhostent _nss_nis_endhostent_XXX
#include <netdb.h>
#undef _nss_nis_endhostent
#include <string.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <resolv/resolv-internal.h>
#include <libc-lock.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>
#include "nss-nis.h"
/* Get implementation for some internal functions. */
#include <resolv/mapv4v6addr.h>
#define ENTNAME hostent
#define DATABASE "hosts"
#define NEED_H_ERRNO
#define EXTRA_ARGS , af, flags
#define EXTRA_ARGS_DECL , int af, int flags
#define ENTDATA hostent_data
struct hostent_data
{
unsigned char host_addr[16]; /* IPv4 or IPv6 address. */
char *h_addr_ptrs[2]; /* Points to that and null terminator. */
};
#define TRAILING_LIST_MEMBER h_aliases
#define TRAILING_LIST_SEPARATOR_P isspace
#include <nss/nss_files/files-parse.c>
LINE_PARSER
("#",
{
char *addr;
STRING_FIELD (addr, isspace, 1);
assert (af == AF_INET || af == AF_INET6 || af == AF_UNSPEC);
/* Parse address. */
if (af != AF_INET6 && inet_pton (AF_INET, addr, entdata->host_addr) > 0)
{
assert ((flags & AI_V4MAPPED) == 0 || af != AF_UNSPEC);
if (flags & AI_V4MAPPED)
{
map_v4v6_address ((char *) entdata->host_addr,
(char *) entdata->host_addr);
result->h_addrtype = AF_INET6;
result->h_length = IN6ADDRSZ;
}
else
{
result->h_addrtype = AF_INET;
result->h_length = INADDRSZ;
}
}
else if (af != AF_INET
&& inet_pton (AF_INET6, addr, entdata->host_addr) > 0)
{
result->h_addrtype = AF_INET6;
result->h_length = IN6ADDRSZ;
}
else
/* Illegal address: ignore line. */
return 0;
/* Store a pointer to the address in the expected form. */
entdata->h_addr_ptrs[0] = (char *) entdata->host_addr;
entdata->h_addr_ptrs[1] = NULL;
result->h_addr_list = entdata->h_addr_ptrs;
STRING_FIELD (result->h_name, isspace, 1);
})
__libc_lock_define_initialized (static, lock)
static bool_t new_start = 1;
static char *oldkey = NULL;
static int oldkeylen = 0;
enum nss_status
_nss_nis_sethostent (int stayopen)
{
__libc_lock_lock (lock);
new_start = 1;
if (oldkey != NULL)
{
free (oldkey);
oldkey = NULL;
oldkeylen = 0;
}
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
/* Make _nss_nis_endhostent an alias of _nss_nis_sethostent. We do this
even though the prototypes don't match. The argument of sethostent
is used so this makes no difference. */
strong_alias (_nss_nis_sethostent, _nss_nis_endhostent)
/* The calling function always need to get a lock first. */
static enum nss_status
internal_nis_gethostent_r (struct hostent *host, char *buffer,
size_t buflen, int *errnop, int *h_errnop,
int af, int flags)
{
char *domain;
if (__glibc_unlikely (yp_get_default_domain (&domain)))
return NSS_STATUS_UNAVAIL;
uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
buffer += pad;
struct parser_data *data = (void *) buffer;
if (__glibc_unlikely (buflen < sizeof *data + 1 + pad))
{
*errnop = ERANGE;
*h_errnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
buflen -= pad;
/* Get the next entry until we found a correct one. */
const size_t linebuflen = buffer + buflen - data->linebuffer;
int parse_res;
do
{
char *result;
int len;
char *outkey;
int keylen;
int yperr;
if (new_start)
yperr = yp_first (domain, "hosts.byname", &outkey, &keylen, &result,
&len);
else
yperr = yp_next (domain, "hosts.byname", oldkey, oldkeylen, &outkey,
&keylen, &result, &len);
if (__glibc_unlikely (yperr != YPERR_SUCCESS))
{
enum nss_status retval = yperr2nss (yperr);
switch (retval)
{
case NSS_STATUS_TRYAGAIN:
*errnop = errno;
*h_errnop = TRY_AGAIN;
break;
case NSS_STATUS_NOTFOUND:
*h_errnop = HOST_NOT_FOUND;
break;
default:
*h_errnop = NO_RECOVERY;
break;
}
return retval;
}
if (__glibc_unlikely ((size_t) (len + 1) > linebuflen))
{
free (result);
*h_errnop = NETDB_INTERNAL;
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
char *p = strncpy (data->linebuffer, result, len);
data->linebuffer[len] = '\0';
while (isspace (*p))
++p;
free (result);
parse_res = parse_line (p, host, data, buflen, errnop, af, flags);
if (__glibc_unlikely (parse_res == -1))
{
free (outkey);
*h_errnop = NETDB_INTERNAL;
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
free (oldkey);
oldkey = outkey;
oldkeylen = keylen;
new_start = 0;
}
while (!parse_res);
*h_errnop = NETDB_SUCCESS;
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_nis_gethostent_r (struct hostent *host, char *buffer, size_t buflen,
int *errnop, int *h_errnop)
{
enum nss_status status;
__libc_lock_lock (lock);
status = internal_nis_gethostent_r (host, buffer, buflen, errnop, h_errnop,
(res_use_inet6 () ? AF_INET6 : AF_INET),
(res_use_inet6 () ? AI_V4MAPPED : 0 ));
__libc_lock_unlock (lock);
return status;
}
static enum nss_status
internal_gethostbyname2_r (const char *name, int af, struct hostent *host,
char *buffer, size_t buflen, int *errnop,
int *h_errnop, int flags)
{
uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
buffer += pad;
struct parser_data *data = (void *) buffer;
if (name == NULL)
{
*errnop = EINVAL;
return NSS_STATUS_UNAVAIL;
}
char *domain;
if (yp_get_default_domain (&domain))
return NSS_STATUS_UNAVAIL;
if (buflen < sizeof *data + 1 + pad)
{
*h_errnop = NETDB_INTERNAL;
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
buflen -= pad;
/* Convert name to lowercase. */
size_t namlen = strlen (name);
/* Limit name length to the maximum size of an RPC packet. */
if (namlen > UDPMSGSIZE)
{
*errnop = ERANGE;
return NSS_STATUS_UNAVAIL;
}
char name2[namlen + 1];
size_t i;
for (i = 0; i < namlen; ++i)
name2[i] = tolower (name[i]);
name2[i] = '\0';
char *result;
int len;
int yperr = yp_match (domain, "hosts.byname", name2, namlen, &result, &len);
if (__glibc_unlikely (yperr != YPERR_SUCCESS))
{
enum nss_status retval = yperr2nss (yperr);
if (retval == NSS_STATUS_TRYAGAIN)
{
*h_errnop = TRY_AGAIN;
*errnop = errno;
}
if (retval == NSS_STATUS_NOTFOUND)
*h_errnop = HOST_NOT_FOUND;
return retval;
}
const size_t linebuflen = buffer + buflen - data->linebuffer;
if (__glibc_unlikely ((size_t) (len + 1) > linebuflen))
{
free (result);
*h_errnop = NETDB_INTERNAL;
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
char *p = strncpy (data->linebuffer, result, len);
data->linebuffer[len] = '\0';
while (isspace (*p))
++p;
free (result);
int parse_res = parse_line (p, host, data, buflen, errnop, af, flags);
if (__glibc_unlikely (parse_res < 1 || host->h_addrtype != af))
{
if (parse_res == -1)
{
*h_errnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
else
{
*h_errnop = HOST_NOT_FOUND;
return NSS_STATUS_NOTFOUND;
}
}
*h_errnop = NETDB_SUCCESS;
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_nis_gethostbyname2_r (const char *name, int af, struct hostent *host,
char *buffer, size_t buflen, int *errnop,
int *h_errnop)
{
if (af != AF_INET && af != AF_INET6)
{
*h_errnop = HOST_NOT_FOUND;
return NSS_STATUS_NOTFOUND;
}
return internal_gethostbyname2_r (name, af, host, buffer, buflen, errnop,
h_errnop,
(res_use_inet6 () ? AI_V4MAPPED : 0));
}
enum nss_status
_nss_nis_gethostbyname_r (const char *name, struct hostent *host, char *buffer,
size_t buflen, int *errnop, int *h_errnop)
{
if (res_use_inet6 ())
{
enum nss_status status;
status = internal_gethostbyname2_r (name, AF_INET6, host, buffer, buflen,
errnop, h_errnop, AI_V4MAPPED);
if (status == NSS_STATUS_SUCCESS)
return status;
}
return internal_gethostbyname2_r (name, AF_INET, host, buffer, buflen,
errnop, h_errnop, 0);
}
enum nss_status
_nss_nis_gethostbyaddr_r (const void *addr, socklen_t addrlen, int af,
struct hostent *host, char *buffer, size_t buflen,
int *errnop, int *h_errnop)
{
char *domain;
if (__glibc_unlikely (yp_get_default_domain (&domain)))
return NSS_STATUS_UNAVAIL;
uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
buffer += pad;
struct parser_data *data = (void *) buffer;
if (__glibc_unlikely (buflen < sizeof *data + 1 + pad))
{
*errnop = ERANGE;
*h_errnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
buflen -= pad;
char *buf = inet_ntoa (*(const struct in_addr *) addr);
char *result;
int len;
int yperr = yp_match (domain, "hosts.byaddr", buf, strlen (buf), &result,
&len);
if (__glibc_unlikely (yperr != YPERR_SUCCESS))
{
enum nss_status retval = yperr2nss (yperr);
if (retval == NSS_STATUS_TRYAGAIN)
{
*h_errnop = TRY_AGAIN;
*errnop = errno;
}
else if (retval == NSS_STATUS_NOTFOUND)
*h_errnop = HOST_NOT_FOUND;
return retval;
}
const size_t linebuflen = buffer + buflen - data->linebuffer;
if (__glibc_unlikely ((size_t) (len + 1) > linebuflen))
{
free (result);
*errnop = ERANGE;
*h_errnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
char *p = strncpy (data->linebuffer, result, len);
data->linebuffer[len] = '\0';
while (isspace (*p))
++p;
free (result);
int parse_res = parse_line (p, host, data, buflen, errnop, af,
(res_use_inet6 () ? AI_V4MAPPED : 0));
if (__glibc_unlikely (parse_res < 1))
{
if (parse_res == -1)
{
*h_errnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
else
{
*h_errnop = HOST_NOT_FOUND;
return NSS_STATUS_NOTFOUND;
}
}
*h_errnop = NETDB_SUCCESS;
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_nis_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
char *buffer, size_t buflen, int *errnop,
int *herrnop, int32_t *ttlp)
{
char *domain;
if (yp_get_default_domain (&domain))
{
*herrnop = NO_DATA;
return NSS_STATUS_UNAVAIL;
}
/* Convert name to lowercase. */
size_t namlen = strlen (name);
/* Limit name length to the maximum size of an RPC packet. */
if (namlen > UDPMSGSIZE)
{
*errnop = ERANGE;
return NSS_STATUS_UNAVAIL;
}
char name2[namlen + 1];
size_t i;
for (i = 0; i < namlen; ++i)
name2[i] = tolower (name[i]);
name2[i] = '\0';
char *result;
int len;
int yperr = yp_match (domain, "hosts.byname", name2, namlen, &result, &len);
if (__glibc_unlikely (yperr != YPERR_SUCCESS))
{
enum nss_status retval = yperr2nss (yperr);
if (retval == NSS_STATUS_TRYAGAIN)
{
*herrnop = TRY_AGAIN;
*errnop = errno;
}
if (retval == NSS_STATUS_NOTFOUND)
*herrnop = HOST_NOT_FOUND;
return retval;
}
if (*pat == NULL)
{
uintptr_t pad = (-(uintptr_t) buffer
% __alignof__ (struct gaih_addrtuple));
buffer += pad;
buflen = buflen > pad ? buflen - pad : 0;
if (__glibc_unlikely (buflen < sizeof (struct gaih_addrtuple)))
{
erange:
free (result);
*errnop = ERANGE;
*herrnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
*pat = (struct gaih_addrtuple *) buffer;
buffer += sizeof (struct gaih_addrtuple);
buflen -= sizeof (struct gaih_addrtuple);
}
uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
buffer += pad;
struct parser_data *data = (void *) buffer;
if (__glibc_unlikely (buflen < sizeof *data + 1 + pad))
goto erange;
buflen -= pad;
struct hostent host;
int parse_res = parse_line (result, &host, data, buflen, errnop, AF_UNSPEC,
0);
if (__glibc_unlikely (parse_res < 1))
{
if (parse_res == -1)
{
*herrnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
else
{
*herrnop = HOST_NOT_FOUND;
return NSS_STATUS_NOTFOUND;
}
}
(*pat)->next = NULL;
(*pat)->family = host.h_addrtype;
memcpy ((*pat)->addr, host.h_addr_list[0], host.h_length);
(*pat)->scopeid = 0;
assert (host.h_addr_list[1] == NULL);
/* Undo the alignment for parser_data. */
buffer -= pad;
buflen += pad;
size_t h_name_len = strlen (host.h_name) + 1;
if (h_name_len >= buflen)
goto erange;
(*pat)->name = memcpy (buffer, host.h_name, h_name_len);
free (result);
return NSS_STATUS_SUCCESS;
}