glibc/nss/getnetgrent_r.c
Arjun Shankar 3f7c7ac887 Move 'netgroup' routines from 'inet' into 'nss'
These netgroup routines are entry points for nss functionality.
This commit moves them along with netgroup.h from the 'inet'
subdirectory to 'nss', and adjusts any references accordingly.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-10-24 12:30:59 +02:00

500 lines
13 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Copyright (C) 1996-2023 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 <atomic.h>
#include <libc-lock.h>
#include <errno.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include "netgroup.h"
#include "nsswitch.h"
#include <sysdep.h>
#include <nscd/nscd_proto.h>
/* Protect above variable against multiple uses at the same time. */
__libc_lock_define_initialized (static, lock)
/* The whole information for the set/get/endnetgrent functions are
kept in this structure. */
static struct __netgrent dataset;
/* Set up NIP to run through the services. Return nonzero if there are no
services (left). */
static int
setup (void **fctp, nss_action_list *nipp)
{
int no_more;
no_more = __nss_netgroup_lookup2 (nipp, "setnetgrent", NULL, 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 (tmp);
}
while (data->needed_groups != NULL)
{
struct name_list *tmp = data->needed_groups;
data->needed_groups = data->needed_groups->next;
free (tmp);
}
}
static void
endnetgrent_hook (struct __netgrent *datap)
{
enum nss_status (*endfct) (struct __netgrent *);
if (datap->nip == NULL || datap->nip == (nss_action_list) -1l)
return;
endfct = __nss_lookup_function (datap->nip, "endnetgrent");
if (endfct != NULL)
(void) (*endfct) (datap);
datap->nip = NULL;
}
static int
__internal_setnetgrent_reuse (const char *group, struct __netgrent *datap,
int *errnop)
{
union
{
enum nss_status (*f) (const char *, struct __netgrent *);
void *ptr;
} fct;
enum nss_status status = NSS_STATUS_UNAVAIL;
struct name_list *new_elem;
/* Free data from previous service. */
endnetgrent_hook (datap);
/* Cycle through all the services and run their setnetgrent functions. */
int no_more = setup (&fct.ptr, &datap->nip);
while (! no_more)
{
assert (datap->data == NULL);
/* Ignore status, we force check in `__nss_next2'. */
status = DL_CALL_FCT (*fct.f, (group, datap));
nss_action_list old_nip = datap->nip;
no_more = __nss_next2 (&datap->nip, "setnetgrent", NULL, &fct.ptr,
status, 0);
if (status == NSS_STATUS_SUCCESS && ! no_more)
{
enum nss_status (*endfct) (struct __netgrent *);
endfct = __nss_lookup_function (old_nip, "endnetgrent");
if (endfct != NULL)
(void) DL_CALL_FCT (*endfct, (datap));
}
}
/* Add the current group to the list of known groups. */
size_t group_len = strlen (group) + 1;
new_elem = (struct name_list *) malloc (sizeof (struct name_list)
+ group_len);
if (new_elem == NULL)
{
*errnop = errno;
status = NSS_STATUS_TRYAGAIN;
}
else
{
new_elem->next = datap->known_groups;
memcpy (new_elem->name, group, group_len);
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);
}
libc_hidden_def (__internal_setnetgrent)
static int
nscd_setnetgrent (const char *group)
{
#ifdef USE_NSCD
if (__nss_not_use_nscd_netgroup > 0
&& ++__nss_not_use_nscd_netgroup > NSS_NSCD_RETRY)
__nss_not_use_nscd_netgroup = 0;
if (!__nss_not_use_nscd_netgroup
&& !__nss_database_custom[NSS_DBSIDX_netgroup])
return __nscd_setnetgrent (group, &dataset);
#endif
return -1;
}
int
setnetgrent (const char *group)
{
int result;
__libc_lock_lock (lock);
result = nscd_setnetgrent (group);
if (result < 0)
result = __internal_setnetgrent (group, &dataset);
__libc_lock_unlock (lock);
return result;
}
void
__internal_endnetgrent (struct __netgrent *datap)
{
endnetgrent_hook (datap);
/* Now free list of all netgroup names from last run. */
free_memory (datap);
}
libc_hidden_def (__internal_endnetgrent)
void
endnetgrent (void)
{
__libc_lock_lock (lock);
__internal_endnetgrent (&dataset);
__libc_lock_unlock (lock);
}
#ifdef USE_NSCD
static const char *
get_nonempty_val (const char *in)
{
if (*in == '\0')
return NULL;
return in;
}
static enum nss_status
nscd_getnetgrent (struct __netgrent *datap, char *buffer, size_t buflen,
int *errnop)
{
if (datap->cursor >= datap->data + datap->data_size)
return NSS_STATUS_UNAVAIL;
datap->type = triple_val;
datap->val.triple.host = get_nonempty_val (datap->cursor);
datap->cursor = strchr (datap->cursor, '\0') + 1;
datap->val.triple.user = get_nonempty_val (datap->cursor);
datap->cursor = strchr (datap->cursor, '\0') + 1;
datap->val.triple.domain = get_nonempty_val (datap->cursor);
datap->cursor = strchr (datap->cursor, '\0') + 1;
return NSS_STATUS_SUCCESS;
}
#endif
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 *);
/* 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. */
int no_more = datap->nip == NULL;
if (! no_more)
{
#ifdef USE_NSCD
/* This bogus function pointer is a special marker left by
__nscd_setnetgrent to tell us to use the data it left
before considering any modules. */
if (datap->nip == (nss_action_list) -1l)
fct = nscd_getnetgrent;
else
#endif
{
fct = __nss_lookup_function (datap->nip, "getnetgrent_r");
no_more = fct == NULL;
}
while (! no_more)
{
status = DL_CALL_FCT (*fct, (datap, buffer, buflen, &errno));
if (status == NSS_STATUS_RETURN
/* The service returned a NOTFOUND, but there are more groups that
we need to resolve before we give up. */
|| (status == NSS_STATUS_NOTFOUND && datap->needed_groups != NULL))
{
/* 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 && datap->nip != NULL)
{
fct = __nss_lookup_function (datap->nip, "getnetgrent_r");
if (fct != NULL)
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)
for (namep = datap->needed_groups; namep != NULL;
namep = namep->next)
if (strcmp (datap->val.group, namep->name) == 0)
break;
if (namep != NULL)
/* Really ignore. */
continue;
size_t group_len = strlen (datap->val.group) + 1;
namep = (struct name_list *) malloc (sizeof (struct name_list)
+ group_len);
if (namep == NULL)
/* We are out of memory. */
status = NSS_STATUS_RETURN;
else
{
namep->next = datap->needed_groups;
memcpy (namep->name, datap->val.group, group_len);
datap->needed_groups = namep;
/* And get the next entry. */
continue;
}
}
break;
}
}
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;
}
libc_hidden_def (__internal_getnetgrent_r)
/* 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)
{
#ifdef USE_NSCD
if (__nss_not_use_nscd_netgroup > 0
&& ++__nss_not_use_nscd_netgroup > NSS_NSCD_RETRY)
__nss_not_use_nscd_netgroup = 0;
if (!__nss_not_use_nscd_netgroup
&& !__nss_database_custom[NSS_DBSIDX_netgroup])
{
int result = __nscd_innetgr (netgroup, host, user, domain);
if (result >= 0)
return result;
}
#endif
union
{
enum nss_status (*f) (const char *, struct __netgrent *);
void *ptr;
} setfct;
void (*endfct) (struct __netgrent *);
int (*getfct) (struct __netgrent *, char *, size_t, int *);
struct __netgrent entry;
int result = 0;
const char *current_group = netgroup;
memset (&entry, '\0', sizeof (entry));
/* 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)
{
int no_more = setup (&setfct.ptr, &entry.nip);
while (! no_more)
{
assert (entry.data == NULL);
/* Open netgroup. */
enum nss_status status = DL_CALL_FCT (*setfct.f,
(current_group, &entry));
if (status == NSS_STATUS_SUCCESS
&& (getfct = __nss_lookup_function (entry.nip, "getnetgrent_r"))
!= NULL)
{
char buffer[1024];
while (DL_CALL_FCT (*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 = entry.known_groups; namep != NULL;
namep = namep->next)
if (strcmp (entry.val.group, namep->name) == 0)
break;
if (namep == NULL)
for (namep = entry.needed_groups; namep != NULL;
namep = namep->next)
if (strcmp (entry.val.group, namep->name) == 0)
break;
if (namep == NULL
&& strcmp (netgroup, entry.val.group) != 0)
{
size_t group_len = strlen (entry.val.group) + 1;
namep =
(struct name_list *) malloc (sizeof (*namep)
+ group_len);
if (namep == NULL)
{
/* Out of memory, simply return. */
result = -1;
break;
}
namep->next = entry.needed_groups;
memcpy (namep->name, entry.val.group, group_len);
entry.needed_groups = namep;
}
}
else
{
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 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. */
endfct = __nss_lookup_function (entry.nip, "endnetgrent");
if (endfct != NULL)
DL_CALL_FCT (*endfct, (&entry));
if (result != 0)
break;
/* Look for the next service. */
no_more = __nss_next2 (&entry.nip, "setnetgrent", NULL,
&setfct.ptr, status, 0);
}
if (result == 0 && entry.needed_groups != NULL)
{
struct name_list *tmp = entry.needed_groups;
entry.needed_groups = tmp->next;
tmp->next = entry.known_groups;
entry.known_groups = tmp;
current_group = tmp->name;
continue;
}
/* No way out. */
break;
}
/* Free the memory. */
free_memory (&entry);
return result == 1;
}
libc_hidden_def (innetgr)