glibc/inet/getnetgrent_r.c

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/* Copyright (C) 1996, 1997, 1998, 1999, 2002 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <bits/libc-lock.h>
#include <errno.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include "netgroup.h"
#include "nsswitch.h"
/* Protect above variable against multiple uses at the same time. */
__libc_lock_define_initialized (static, lock)
/* This handle for the NSS data base is shared between all
set/get/endXXXent functions. */
static service_user *nip;
/* The whole information for the set/get/endnetgrent functions are
kept in this structure. */
static struct __netgrent dataset;
/* The lookup function for the first entry of this service. */
extern int __nss_netgroup_lookup (service_user **nip, const char *name,
void **fctp) internal_function;
/* Set up NIP to run through the services. If ALL is zero, use NIP's
current location if it's not nil. Return nonzero if there are no
services (left). */
static enum nss_status
setup (void **fctp, const char *func_name, int all)
{
/* Remember the first service_entry, it's always the same. */
static service_user *startp;
int no_more;
if (startp == NULL)
{
no_more = __nss_netgroup_lookup (&nip, func_name, fctp);
startp = no_more ? (service_user *) -1 : nip;
}
else if (startp == (service_user *) -1)
/* No services at all. */
return 1;
else
{
if (all || !nip)
/* Reset to the beginning of the service list. */
nip = startp;
/* Look up the first function. */
no_more = __nss_lookup (&nip, func_name, fctp);
}
return no_more;
}
/* Free used memory. */
static void
free_memory (struct __netgrent *data)
{
while (data->known_groups != NULL)
{
struct name_list *tmp = data->known_groups;
data->known_groups = data->known_groups->next;
free ((void *) tmp->name);
free (tmp);
}
while (data->needed_groups != NULL)
{
struct name_list *tmp = data->needed_groups;
data->needed_groups = data->needed_groups->next;
free ((void *) tmp->name);
free (tmp);
}
}
static int
internal_function
__internal_setnetgrent_reuse (const char *group, struct __netgrent *datap,
int *errnop)
{
enum nss_status (*fct) (const char *, struct __netgrent *);
enum nss_status status = NSS_STATUS_UNAVAIL;
struct name_list *new_elem;
int no_more;
/* Cycle through all the services and run their setnetgrent functions. */
no_more = setup ((void **) &fct, "setnetgrent", 1);
while (! no_more)
{
/* Ignore status, we force check in `__nss_next'. */
status = (*fct) (group, datap);
no_more = __nss_next (&nip, "setnetgrent", (void **) &fct, status, 0);
}
/* Add the current group to the list of known groups. */
new_elem = (struct name_list *) malloc (sizeof (struct name_list));
if (new_elem == NULL || (new_elem->name = __strdup (group)) == NULL)
{
if (new_elem != NULL)
free (new_elem);
*errnop = errno;
status = NSS_STATUS_TRYAGAIN;
}
else
{
new_elem->next = datap->known_groups;
datap->known_groups = new_elem;
}
return status == NSS_STATUS_SUCCESS;
}
int
__internal_setnetgrent (const char *group, struct __netgrent *datap)
{
/* Free list of all netgroup names from last run. */
free_memory (datap);
return __internal_setnetgrent_reuse (group, datap, &errno);
}
int
setnetgrent (const char *group)
{
int result;
__libc_lock_lock (lock);
result = __internal_setnetgrent (group, &dataset);
__libc_lock_unlock (lock);
return result;
}
void
__internal_endnetgrent (struct __netgrent *datap)
{
service_user *old_nip;
enum nss_status (*fct) (struct __netgrent *);
int no_more;
/* Remember which was the last used service. */
old_nip = nip;
/* Cycle through all the services and run their endnetgrent functions. */
no_more = setup ((void **) &fct, "endnetgrent", 1);
while (! no_more)
{
/* Ignore status, we force check in `__nss_next'. */
(void) (*fct) (datap);
no_more = (nip == old_nip
|| __nss_next (&nip, "endnetgrent", (void **) &fct, 0, 1));
}
/* Now free list of all netgroup names from last run. */
free_memory (datap);
}
void
endnetgrent (void)
{
__libc_lock_lock (lock);
__internal_endnetgrent (&dataset);
__libc_lock_unlock (lock);
}
int
__internal_getnetgrent_r (char **hostp, char **userp, char **domainp,
struct __netgrent *datap,
char *buffer, size_t buflen, int *errnop)
{
enum nss_status (*fct) (struct __netgrent *, char *, size_t, int *);
int no_more;
/* Initialize status to return if no more functions are found. */
enum nss_status status = NSS_STATUS_NOTFOUND;
/* Run through available functions, starting with the same function last
run. We will repeat each function as long as it succeeds, and then go
on to the next service action. */
no_more = setup ((void **) &fct, "getnetgrent_r", 0);
while (! no_more)
{
status = (*fct) (datap, buffer, buflen, &errno);
if (status == NSS_STATUS_RETURN)
{
/* This was the last one for this group. Look at next group
if available. */
int found = 0;
while (datap->needed_groups != NULL && ! found)
{
struct name_list *tmp = datap->needed_groups;
datap->needed_groups = datap->needed_groups->next;
tmp->next = datap->known_groups;
datap->known_groups = tmp;
found = __internal_setnetgrent_reuse (datap->known_groups->name,
datap, errnop);
}
if (found)
continue;
}
else if (status == NSS_STATUS_SUCCESS && datap->type == group_val)
{
/* The last entry was a name of another netgroup. */
struct name_list *namep;
/* Ignore if we've seen the name before. */
for (namep = datap->known_groups; namep != NULL;
namep = namep->next)
if (strcmp (datap->val.group, namep->name) == 0)
break;
if (namep != NULL)
/* Really ignore. */
continue;
namep = (struct name_list *) malloc (sizeof (struct name_list));
if (namep == NULL
|| (namep->name = __strdup (datap->val.group)) == NULL)
{
/* We are out of memory. */
if (namep != NULL)
free (namep);
status = NSS_STATUS_RETURN;
}
else
{
namep->next = datap->needed_groups;
datap->needed_groups = namep;
/* And get the next entry. */
continue;
}
}
no_more = __nss_next (&nip, "getnetgrent_r", (void **) &fct, status, 0);
}
if (status == NSS_STATUS_SUCCESS)
{
*hostp = (char *) datap->val.triple.host;
*userp = (char *) datap->val.triple.user;
*domainp = (char *) datap->val.triple.domain;
}
return status == NSS_STATUS_SUCCESS ? 1 : 0;
}
/* The real entry point. */
int
__getnetgrent_r (char **hostp, char **userp, char **domainp,
char *buffer, size_t buflen)
{
enum nss_status status;
__libc_lock_lock (lock);
status = __internal_getnetgrent_r (hostp, userp, domainp, &dataset,
buffer, buflen, &errno);
__libc_lock_unlock (lock);
return status;
}
weak_alias (__getnetgrent_r, getnetgrent_r)
/* Test whether given (host,user,domain) triple is in NETGROUP. */
int
innetgr (const char *netgroup, const char *host, const char *user,
const char *domain)
{
int (*setfct) (const char *, struct __netgrent *);
void (*endfct) (struct __netgrent *);
int (*getfct) (struct __netgrent *, char *, size_t, int *);
struct name_list *known = NULL;
struct name_list *needed = NULL;
int result = 0;
int no_more;
const char *current_group = netgroup;
int real_entry = 0;
/* Walk through the services until we found an answer or we shall
not work further. We can do some optimization here. Since all
services must provide the `setnetgrent' function we can do all
the work during one walk through the service list. */
while (1)
{
no_more = setup ((void **) &setfct, "setnetgrent", 1);
while (! no_more)
{
enum nss_status status;
struct __netgrent entry;
/* Clear the space for the netgroup data. */
__bzero (&entry, sizeof (entry));
/* Open netgroup. */
status = (*setfct) (current_group, &entry);
if (status == NSS_STATUS_SUCCESS
&& __nss_lookup (&nip, "getnetgrent_r", (void **) &getfct) == 0)
{
char buffer[1024];
while ((*getfct) (&entry, buffer, sizeof buffer, &errno)
== NSS_STATUS_SUCCESS)
{
if (entry.type == group_val)
{
/* Make sure we haven't seen the name before. */
struct name_list *namep;
for (namep = known; namep != NULL; namep = namep->next)
if (strcmp (entry.val.group, namep->name) == 0)
break;
if (namep == NULL
&& strcmp (netgroup, entry.val.group) != 0)
{
namep =
(struct name_list *) malloc (sizeof (*namep));
if (namep == NULL
|| ((namep->name = __strdup (entry.val.group))
== NULL))
{
/* Out of memory, simply return. */
if (namep != NULL)
free (namep);
result = -1;
break;
}
namep->next = needed;
needed = namep;
}
}
else
{
real_entry = 1;
if ((entry.val.triple.host == NULL || host == NULL
|| __strcasecmp (entry.val.triple.host, host) == 0)
&& (entry.val.triple.user == NULL || user == NULL
|| strcmp (entry.val.triple.user, user) == 0)
&& (entry.val.triple.domain == NULL || domain == NULL
|| __strcasecmp (entry.val.triple.domain,
domain) == 0))
{
result = 1;
break;
}
}
}
if (result != 0)
break;
/* If we found one service which does know the given
netgroup we don't try further. */
status = NSS_STATUS_RETURN;
}
/* Free all resources of the service. */
if (__nss_lookup (&nip, "endnetgrent", (void **) &endfct) == 0)
(*endfct) (&entry);
/* Look for the next service. */
no_more = __nss_next (&nip, "setnetgrent",
(void **) &setfct, status, 0);
}
if (result == 0 && needed != NULL)
{
struct name_list *tmp = needed;
needed = tmp->next;
tmp->next = known;
known = tmp;
current_group = known->name;
continue;
}
/* No way out. */
break;
}
/* Free the memory. */
while (known != NULL)
{
struct name_list *tmp = known;
known = known->next;
free ((void *) tmp->name);
free (tmp);
}
while (needed != NULL)
{
struct name_list *tmp = needed;
needed = needed->next;
free ((void *) tmp->name);
free (tmp);
}
return result == 1;
}