glibc/nis/nss_nis/nis-alias.c

282 lines
6.4 KiB
C

/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.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
<https://www.gnu.org/licenses/>. */
#include <nss.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <aliases.h>
#include <libc-lock.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>
#include "nss-nis.h"
__libc_lock_define_initialized (static, lock)
static bool_t new_start = 1;
static char *oldkey;
static int oldkeylen;
static int
_nss_nis_parse_aliasent (const char *key, char *alias, struct aliasent *result,
char *buffer, size_t buflen, int *errnop)
{
char *first_unused = buffer + strlen (alias) + 1;
size_t room_left =
buflen - (buflen % __alignof__ (char *)) - strlen (alias) - 2;
char *line;
char *cp;
result->alias_members_len = 0;
*first_unused = '\0';
first_unused++;
strcpy (first_unused, key);
if (first_unused[room_left - 1] != '\0')
{
/* The line is too long for our buffer. */
no_more_room:
*errnop = ERANGE;
return -1;
}
result->alias_name = first_unused;
/* Terminate the line for any case. */
cp = strpbrk (alias, "#\n");
if (cp != NULL)
*cp = '\0';
first_unused += strlen (result->alias_name) + 1;
/* Adjust the pointer so it is aligned for
storing pointers. */
first_unused += __alignof__ (char *) - 1;
first_unused -= ((first_unused - (char *) 0) % __alignof__ (char *));
result->alias_members = (char **) first_unused;
line = alias;
while (*line != '\0')
{
/* Skip leading blanks. */
while (isspace (*line))
line++;
if (*line == '\0')
break;
if (room_left < sizeof (char *))
goto no_more_room;
room_left -= sizeof (char *);
result->alias_members[result->alias_members_len] = line;
while (*line != '\0' && *line != ',')
line++;
if (line != result->alias_members[result->alias_members_len])
{
*line = '\0';
line++;
result->alias_members_len++;
}
}
return result->alias_members_len == 0 ? 0 : 1;
}
enum nss_status
_nss_nis_setaliasent (void)
{
__libc_lock_lock (lock);
new_start = 1;
if (oldkey != NULL)
{
free (oldkey);
oldkey = NULL;
oldkeylen = 0;
}
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
/* The 'endaliasent' function is identical. */
strong_alias (_nss_nis_setaliasent, _nss_nis_endaliasent)
static enum nss_status
internal_nis_getaliasent_r (struct aliasent *alias, char *buffer,
size_t buflen, int *errnop)
{
char *domain;
if (__glibc_unlikely (yp_get_default_domain (&domain)))
return NSS_STATUS_UNAVAIL;
alias->alias_local = 0;
/* Get the next entry until we found a correct one. */
int parse_res;
do
{
char *result;
int len;
char *outkey;
int keylen;
int yperr;
if (new_start)
yperr = yp_first (domain, "mail.aliases", &outkey, &keylen, &result,
&len);
else
yperr = yp_next (domain, "mail.aliases", oldkey, oldkeylen, &outkey,
&keylen, &result, &len);
if (__glibc_unlikely (yperr != YPERR_SUCCESS))
{
enum nss_status retval = yperr2nss (yperr);
if (retval == NSS_STATUS_TRYAGAIN)
*errnop = errno;
return retval;
}
if (__glibc_unlikely ((size_t) (len + 1) > buflen))
{
free (result);
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
char *p = strncpy (buffer, result, len);
buffer[len] = '\0';
while (isspace (*p))
++p;
free (result);
parse_res = _nss_nis_parse_aliasent (outkey, p, alias, buffer,
buflen, errnop);
if (__glibc_unlikely (parse_res == -1))
{
free (outkey);
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
free (oldkey);
oldkey = outkey;
oldkeylen = keylen;
new_start = 0;
}
while (!parse_res);
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_nis_getaliasent_r (struct aliasent *alias, char *buffer, size_t buflen,
int *errnop)
{
enum nss_status status;
__libc_lock_lock (lock);
status = internal_nis_getaliasent_r (alias, buffer, buflen, errnop);
__libc_lock_unlock (lock);
return status;
}
enum nss_status
_nss_nis_getaliasbyname_r (const char *name, struct aliasent *alias,
char *buffer, size_t buflen, int *errnop)
{
if (name == NULL)
{
*errnop = EINVAL;
return NSS_STATUS_UNAVAIL;
}
char *domain;
if (__glibc_unlikely (yp_get_default_domain (&domain)))
return NSS_STATUS_UNAVAIL;
size_t namlen = strlen (name);
char *name2;
int use_alloca = __libc_use_alloca (namlen + 1);
if (use_alloca)
name2 = __alloca (namlen + 1);
else
{
name2 = malloc (namlen + 1);
if (name2 == NULL)
{
*errnop = ENOMEM;
return NSS_STATUS_TRYAGAIN;
}
}
/* Convert name to lowercase. */
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, "mail.aliases", name2, namlen, &result, &len);
if (!use_alloca)
free (name2);
if (__glibc_unlikely (yperr != YPERR_SUCCESS))
{
enum nss_status retval = yperr2nss (yperr);
if (retval == NSS_STATUS_TRYAGAIN)
*errnop = errno;
return retval;
}
if (__glibc_unlikely ((size_t) (len + 1) > buflen))
{
free (result);
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
char *p = strncpy (buffer, result, len);
buffer[len] = '\0';
while (isspace (*p))
++p;
free (result);
alias->alias_local = 0;
int parse_res = _nss_nis_parse_aliasent (name, p, alias, buffer, buflen,
errnop);
if (__glibc_unlikely (parse_res < 1))
{
if (parse_res == -1)
return NSS_STATUS_TRYAGAIN;
else
return NSS_STATUS_NOTFOUND;
}
return NSS_STATUS_SUCCESS;
}