nscd/nscd_getgr_r.c - nest-cam/v366/glibc - Git at Google

 /* Copyright (C) 1998-2000, 2002-2005, 2006, 2007, 2009
    Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1998.

    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 <alloca.h>
 #include <assert.h>
 #include <errno.h>
 #include <grp.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
 #include <sys/uio.h>
 #include <sys/un.h>
 #include <not-cancel.h>
 #include <stdio-common/_itoa.h>

 #include "nscd-client.h"
 #include "nscd_proto.h"

 int __nss_not_use_nscd_group;

 static int nscd_getgr_r (const char *key, size_t keylen, request_type type,
 			 struct group *resultbuf, char *buffer,
 			 size_t buflen, struct group **result)
      internal_function;


 int
 __nscd_getgrnam_r (const char *name, struct group *resultbuf, char *buffer,
 		   size_t buflen, struct group **result)
 {
   return nscd_getgr_r (name, strlen (name) + 1, GETGRBYNAME, resultbuf,
 		       buffer, buflen, result);
 }


 int
 __nscd_getgrgid_r (gid_t gid, struct group *resultbuf, char *buffer,
 		   size_t buflen, struct group **result)
 {
   char buf[3 * sizeof (gid_t)];
   buf[sizeof (buf) - 1] = '\0';
   char *cp = _itoa_word (gid, buf + sizeof (buf) - 1, 10, 0);

   return nscd_getgr_r (cp, buf + sizeof (buf) - cp, GETGRBYGID, resultbuf,
 		       buffer, buflen, result);
 }


 libc_locked_map_ptr (,__gr_map_handle) attribute_hidden;
 /* Note that we only free the structure if necessary.  The memory
    mapping is not removed since it is not visible to the malloc
    handling.  */
 libc_freeres_fn (gr_map_free)
 {
   if (__gr_map_handle.mapped != NO_MAPPING)
     {
       void *p = __gr_map_handle.mapped;
       __gr_map_handle.mapped = NO_MAPPING;
       free (p);
     }
 }


 static int
 internal_function
 nscd_getgr_r (const char *key, size_t keylen, request_type type,
 	      struct group *resultbuf, char *buffer, size_t buflen,
 	      struct group **result)
 {
   int gc_cycle;
   int nretries = 0;
   const uint32_t *len = NULL;
   size_t lensize = 0;

   /* If the mapping is available, try to search there instead of
      communicating with the nscd.  */
   struct mapped_database *mapped = __nscd_get_map_ref (GETFDGR, "group",
 						       &__gr_map_handle,
 						       &gc_cycle);
  retry:;
   const char *gr_name = NULL;
   size_t gr_name_len = 0;
   int retval = -1;
   const char *recend = (const char *) ~UINTMAX_C (0);
   gr_response_header gr_resp;

   if (mapped != NO_MAPPING)
     {
       struct datahead *found = __nscd_cache_search (type, key, keylen, mapped,
 						    sizeof gr_resp);
       if (found != NULL)
 	{
 	  len = (const uint32_t *) (&found->data[0].grdata + 1);
 	  gr_resp = found->data[0].grdata;
 	  gr_name = ((const char *) len
 		     + gr_resp.gr_mem_cnt * sizeof (uint32_t));
 	  gr_name_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 	  recend = (const char *) found->data + found->recsize;
 	  /* Now check if we can trust gr_resp fields.  If GC is
 	     in progress, it can contain anything.  */
 	  if (mapped->head->gc_cycle != gc_cycle)
 	    {
 	      retval = -2;
 	      goto out;
 	    }

 	  /* The alignment is always sufficient, unless GC is in progress.  */
 	  assert (((uintptr_t) len & (__alignof__ (*len) - 1)) == 0);
 	}
     }

   int sock = -1;
   if (gr_name == NULL)
     {
       sock = __nscd_open_socket (key, keylen, type, &gr_resp,
 				 sizeof (gr_resp));
       if (sock == -1)
 	{
 	  __nss_not_use_nscd_group = 1;
 	  goto out;
 	}
     }

   /* No value found so far.  */
   *result = NULL;

   if (__builtin_expect (gr_resp.found == -1, 0))
     {
       /* The daemon does not cache this database.  */
       __nss_not_use_nscd_group = 1;
       goto out_close;
     }

   if (gr_resp.found == 1)
     {
       struct iovec vec[2];
       char *p = buffer;
       size_t total_len;
       uintptr_t align;
       nscd_ssize_t cnt;

       /* Now allocate the buffer the array for the group members.  We must
 	 align the pointer.  */
       align = ((__alignof__ (char *) - (p - ((char *) 0)))
 	       & (__alignof__ (char *) - 1));
       total_len = (align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *)
 		   + gr_resp.gr_name_len + gr_resp.gr_passwd_len);
       if (__builtin_expect (buflen < total_len, 0))
 	{
 	no_room:
 	  __set_errno (ERANGE);
 	  retval = ERANGE;
 	  goto out_close;
 	}
       buflen -= total_len;

       p += align;
       resultbuf->gr_mem = (char **) p;
       p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *);

       /* Set pointers for strings.  */
       resultbuf->gr_name = p;
       p += gr_resp.gr_name_len;
       resultbuf->gr_passwd = p;
       p += gr_resp.gr_passwd_len;

       /* Fill in what we know now.  */
       resultbuf->gr_gid = gr_resp.gr_gid;

       /* Read the length information, group name, and password.  */
       if (gr_name == NULL)
 	{
 	  /* Handle a simple, usual case: no group members.  */
 	  if (__builtin_expect (gr_resp.gr_mem_cnt == 0, 1))
 	    {
 	      size_t n = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 	      if (__builtin_expect (__readall (sock, resultbuf->gr_name, n)
 				    != (ssize_t) n, 0))
 		goto out_close;
 	    }
 	  else
 	    {
 	      /* Allocate array to store lengths.  */
 	      if (lensize == 0)
 		{
 		  lensize = gr_resp.gr_mem_cnt * sizeof (uint32_t);
 		  len = (uint32_t *) alloca (lensize);
 		}
 	      else if (gr_resp.gr_mem_cnt * sizeof (uint32_t) > lensize)
 		len = extend_alloca (len, lensize,
 				     gr_resp.gr_mem_cnt * sizeof (uint32_t));

 	      vec[0].iov_base = (void *) len;
 	      vec[0].iov_len = gr_resp.gr_mem_cnt * sizeof (uint32_t);
 	      vec[1].iov_base = resultbuf->gr_name;
 	      vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
 	      total_len = vec[0].iov_len + vec[1].iov_len;

 	      /* Get this data.  */
 	      size_t n = __readvall (sock, vec, 2);
 	      if (__builtin_expect (n != total_len, 0))
 		goto out_close;
 	    }
 	}
       else
 	/* We already have the data.  Just copy the group name and
 	   password.  */
 	memcpy (resultbuf->gr_name, gr_name,
 		gr_resp.gr_name_len + gr_resp.gr_passwd_len);

       /* Clear the terminating entry.  */
       resultbuf->gr_mem[gr_resp.gr_mem_cnt] = NULL;

       /* Prepare reading the group members.  */
       total_len = 0;
       for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
 	{
 	  resultbuf->gr_mem[cnt] = p;
 	  total_len += len[cnt];
 	  p += len[cnt];
 	}

       if (__builtin_expect (gr_name + gr_name_len + total_len > recend, 0))
 	{
 	  /* len array might contain garbage during nscd GC cycle,
 	     retry rather than fail in that case.  */
 	  if (gr_name != NULL && mapped->head->gc_cycle != gc_cycle)
 	    retval = -2;
 	  goto out_close;
 	}
       if (__builtin_expect (total_len > buflen, 0))
 	{
 	  /* len array might contain garbage during nscd GC cycle,
 	     retry rather than fail in that case.  */
 	  if (gr_name != NULL && mapped->head->gc_cycle != gc_cycle)
 	    {
 	      retval = -2;
 	      goto out_close;
 	    }
 	  else
 	    goto no_room;
 	}

       retval = 0;

       /* If there are no group members TOTAL_LEN is zero.  */
       if (gr_name == NULL)
 	{
 	  if (total_len > 0
 	      && __builtin_expect (__readall (sock, resultbuf->gr_mem[0],
 					      total_len) != total_len, 0))
 	    {
 	      /* The `errno' to some value != ERANGE.  */
 	      __set_errno (ENOENT);
 	      retval = ENOENT;
 	    }
 	  else
 	    *result = resultbuf;
 	}
       else
 	{
 	  /* Copy the group member names.  */
 	  memcpy (resultbuf->gr_mem[0], gr_name + gr_name_len, total_len);

 	  /* Try to detect corrupt databases.  */
 	  if (resultbuf->gr_name[gr_name_len - 1] != '\0'
 	      || resultbuf->gr_passwd[gr_resp.gr_passwd_len - 1] != '\0'
 	      || ({for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
 		    if (resultbuf->gr_mem[cnt][len[cnt] - 1] != '\0')
 		      break;
 		  cnt < gr_resp.gr_mem_cnt; }))
 	    {
 	      /* We cannot use the database.  */
 	      retval = mapped->head->gc_cycle != gc_cycle ? -2 : -1;
 	      goto out_close;
 	    }

 	  *result = resultbuf;
 	}
     }
   else
     {
       /* Set errno to 0 to indicate no error, just no found record.  */
       __set_errno (0);
       /* Even though we have not found anything, the result is zero.  */
       retval = 0;
     }

  out_close:
   if (sock != -1)
     close_not_cancel_no_status (sock);
  out:
   if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)
     {
       /* When we come here this means there has been a GC cycle while we
 	 were looking for the data.  This means the data might have been
 	 inconsistent.  Retry if possible.  */
       if ((gc_cycle & 1) != 0 || ++nretries == 5 || retval == -1)
 	{
 	  /* nscd is just running gc now.  Disable using the mapping.  */
 	  if (atomic_decrement_val (&mapped->counter) == 0)
 	    __nscd_unmap (mapped);
 	  mapped = NO_MAPPING;
 	}

       if (retval != -1)
 	goto retry;
     }

   return retval;
 }
	/* Copyright (C) 1998-2000, 2002-2005, 2006, 2007, 2009
	Free Software Foundation, Inc.
	This file is part of the GNU C Library.
	Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1998.

	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 <alloca.h>
	#include <assert.h>
	#include <errno.h>
	#include <grp.h>
	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>
	#include <sys/mman.h>
	#include <sys/socket.h>
	#include <sys/uio.h>
	#include <sys/un.h>
	#include <not-cancel.h>
	#include <stdio-common/_itoa.h>

	#include "nscd-client.h"
	#include "nscd_proto.h"

	int __nss_not_use_nscd_group;

	static int nscd_getgr_r (const char *key, size_t keylen, request_type type,
	struct group resultbuf, char buffer,
	size_t buflen, struct group **result)
	internal_function;


	int
	__nscd_getgrnam_r (const char name, struct group resultbuf, char *buffer,
	size_t buflen, struct group **result)
	{
	return nscd_getgr_r (name, strlen (name) + 1, GETGRBYNAME, resultbuf,
	buffer, buflen, result);
	}


	int
	__nscd_getgrgid_r (gid_t gid, struct group resultbuf, char buffer,
	size_t buflen, struct group **result)
	{
	char buf[3 * sizeof (gid_t)];
	buf[sizeof (buf) - 1] = '\0';
	char *cp = _itoa_word (gid, buf + sizeof (buf) - 1, 10, 0);

	return nscd_getgr_r (cp, buf + sizeof (buf) - cp, GETGRBYGID, resultbuf,
	buffer, buflen, result);
	}


	libc_locked_map_ptr (,__gr_map_handle) attribute_hidden;
	/* Note that we only free the structure if necessary. The memory
	mapping is not removed since it is not visible to the malloc
	handling. */
	libc_freeres_fn (gr_map_free)
	{
	if (__gr_map_handle.mapped != NO_MAPPING)
	{
	void *p = __gr_map_handle.mapped;
	__gr_map_handle.mapped = NO_MAPPING;
	free (p);
	}
	}


	static int
	internal_function
	nscd_getgr_r (const char *key, size_t keylen, request_type type,
	struct group resultbuf, char buffer, size_t buflen,
	struct group **result)
	{
	int gc_cycle;
	int nretries = 0;
	const uint32_t *len = NULL;
	size_t lensize = 0;

	/* If the mapping is available, try to search there instead of
	communicating with the nscd. */
	struct mapped_database *mapped = __nscd_get_map_ref (GETFDGR, "group",
	&__gr_map_handle,
	&gc_cycle);
	retry:;
	const char *gr_name = NULL;
	size_t gr_name_len = 0;
	int retval = -1;
	const char recend = (const char ) ~UINTMAX_C (0);
	gr_response_header gr_resp;

	if (mapped != NO_MAPPING)
	{
	struct datahead *found = __nscd_cache_search (type, key, keylen, mapped,
	sizeof gr_resp);
	if (found != NULL)
	{
	len = (const uint32_t *) (&found->data[0].grdata + 1);
	gr_resp = found->data[0].grdata;
	gr_name = ((const char *) len
	+ gr_resp.gr_mem_cnt * sizeof (uint32_t));
	gr_name_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
	recend = (const char *) found->data + found->recsize;
	/* Now check if we can trust gr_resp fields. If GC is
	in progress, it can contain anything. */
	if (mapped->head->gc_cycle != gc_cycle)
	{
	retval = -2;
	goto out;
	}

	/* The alignment is always sufficient, unless GC is in progress. */
	assert (((uintptr_t) len & (__alignof__ (*len) - 1)) == 0);
	}
	}

	int sock = -1;
	if (gr_name == NULL)
	{
	sock = __nscd_open_socket (key, keylen, type, &gr_resp,
	sizeof (gr_resp));
	if (sock == -1)
	{
	__nss_not_use_nscd_group = 1;
	goto out;
	}
	}

	/* No value found so far. */
	*result = NULL;

	if (__builtin_expect (gr_resp.found == -1, 0))
	{
	/* The daemon does not cache this database. */
	__nss_not_use_nscd_group = 1;
	goto out_close;
	}

	if (gr_resp.found == 1)
	{
	struct iovec vec[2];
	char *p = buffer;
	size_t total_len;
	uintptr_t align;
	nscd_ssize_t cnt;

	/* Now allocate the buffer the array for the group members. We must
	align the pointer. */
	align = ((__alignof__ (char ) - (p - ((char ) 0)))
	& (__alignof__ (char *) - 1));
	total_len = (align + (1 + gr_resp.gr_mem_cnt) * sizeof (char *)
	+ gr_resp.gr_name_len + gr_resp.gr_passwd_len);
	if (__builtin_expect (buflen < total_len, 0))
	{
	no_room:
	__set_errno (ERANGE);
	retval = ERANGE;
	goto out_close;
	}
	buflen -= total_len;

	p += align;
	resultbuf->gr_mem = (char **) p;
	p += (1 + gr_resp.gr_mem_cnt) * sizeof (char *);

	/* Set pointers for strings. */
	resultbuf->gr_name = p;
	p += gr_resp.gr_name_len;
	resultbuf->gr_passwd = p;
	p += gr_resp.gr_passwd_len;

	/* Fill in what we know now. */
	resultbuf->gr_gid = gr_resp.gr_gid;

	/* Read the length information, group name, and password. */
	if (gr_name == NULL)
	{
	/* Handle a simple, usual case: no group members. */
	if (__builtin_expect (gr_resp.gr_mem_cnt == 0, 1))
	{
	size_t n = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
	if (__builtin_expect (__readall (sock, resultbuf->gr_name, n)
	!= (ssize_t) n, 0))
	goto out_close;
	}
	else
	{
	/* Allocate array to store lengths. */
	if (lensize == 0)
	{
	lensize = gr_resp.gr_mem_cnt * sizeof (uint32_t);
	len = (uint32_t *) alloca (lensize);
	}
	else if (gr_resp.gr_mem_cnt * sizeof (uint32_t) > lensize)
	len = extend_alloca (len, lensize,
	gr_resp.gr_mem_cnt * sizeof (uint32_t));

	vec[0].iov_base = (void *) len;
	vec[0].iov_len = gr_resp.gr_mem_cnt * sizeof (uint32_t);
	vec[1].iov_base = resultbuf->gr_name;
	vec[1].iov_len = gr_resp.gr_name_len + gr_resp.gr_passwd_len;
	total_len = vec[0].iov_len + vec[1].iov_len;

	/* Get this data. */
	size_t n = __readvall (sock, vec, 2);
	if (__builtin_expect (n != total_len, 0))
	goto out_close;
	}
	}
	else
	/* We already have the data. Just copy the group name and
	password. */
	memcpy (resultbuf->gr_name, gr_name,
	gr_resp.gr_name_len + gr_resp.gr_passwd_len);

	/* Clear the terminating entry. */
	resultbuf->gr_mem[gr_resp.gr_mem_cnt] = NULL;

	/* Prepare reading the group members. */
	total_len = 0;
	for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
	{
	resultbuf->gr_mem[cnt] = p;
	total_len += len[cnt];
	p += len[cnt];
	}

	if (__builtin_expect (gr_name + gr_name_len + total_len > recend, 0))
	{
	/* len array might contain garbage during nscd GC cycle,
	retry rather than fail in that case. */
	if (gr_name != NULL && mapped->head->gc_cycle != gc_cycle)
	retval = -2;
	goto out_close;
	}
	if (__builtin_expect (total_len > buflen, 0))
	{
	/* len array might contain garbage during nscd GC cycle,
	retry rather than fail in that case. */
	if (gr_name != NULL && mapped->head->gc_cycle != gc_cycle)
	{
	retval = -2;
	goto out_close;
	}
	else
	goto no_room;
	}

	retval = 0;

	/* If there are no group members TOTAL_LEN is zero. */
	if (gr_name == NULL)
	{
	if (total_len > 0
	&& __builtin_expect (__readall (sock, resultbuf->gr_mem[0],
	total_len) != total_len, 0))
	{
	/* The `errno' to some value != ERANGE. */
	__set_errno (ENOENT);
	retval = ENOENT;
	}
	else
	*result = resultbuf;
	}
	else
	{
	/* Copy the group member names. */
	memcpy (resultbuf->gr_mem[0], gr_name + gr_name_len, total_len);

	/* Try to detect corrupt databases. */
	if (resultbuf->gr_name[gr_name_len - 1] != '\0'
	\|\| resultbuf->gr_passwd[gr_resp.gr_passwd_len - 1] != '\0'
	\|\| ({for (cnt = 0; cnt < gr_resp.gr_mem_cnt; ++cnt)
	if (resultbuf->gr_mem[cnt][len[cnt] - 1] != '\0')
	break;
	cnt < gr_resp.gr_mem_cnt; }))
	{
	/* We cannot use the database. */
	retval = mapped->head->gc_cycle != gc_cycle ? -2 : -1;
	goto out_close;
	}

	*result = resultbuf;
	}
	}
	else
	{
	/* Set errno to 0 to indicate no error, just no found record. */
	__set_errno (0);
	/* Even though we have not found anything, the result is zero. */
	retval = 0;
	}

	out_close:
	if (sock != -1)
	close_not_cancel_no_status (sock);
	out:
	if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0)
	{
	/* When we come here this means there has been a GC cycle while we
	were looking for the data. This means the data might have been
	inconsistent. Retry if possible. */
	if ((gc_cycle & 1) != 0 \|\| ++nretries == 5 \|\| retval == -1)
	{
	/* nscd is just running gc now. Disable using the mapping. */
	if (atomic_decrement_val (&mapped->counter) == 0)
	__nscd_unmap (mapped);
	mapped = NO_MAPPING;
	}

	if (retval != -1)
	goto retry;
	}

	return retval;
	}