text: /* Initgroups handling in nss_db module.
     Copyright (C) 2011-2015 Free Software Foundation, Inc.
     This file is part of the GNU C Library.
     Contributed by Ulrich Drepper <drepper@gmail.com>.
  
     The GNU C Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public License as
     published by the Free Software Foundation; either version 2 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
     Library General Public License for more details.
  
     You should have received a copy of the GNU Library General Public
     License along with the GNU C Library; see the file COPYING.LIB.  If
     not, see <http://www.gnu.org/licenses/>.  */
  
  #include <ctype.h>
  #include <errno.h>
  #include <grp.h>
  #include <limits.h>
  #include <paths.h>
  #include <stdlib.h>
  #include <string.h>
  #include <stdint.h>
  #include <sys/param.h>
  
  #include "nss_db.h"
  
  /* The hashing function we use.  */
  #include "../intl/hash-string.h"
  
  
  enum nss_status
  _nss_db_initgroups_dyn (const char *user, gid_t group, long int *start,
  			long int *size, gid_t **groupsp, long int limit,
  			int *errnop)
  {
    struct nss_db_map state = { NULL, 0 };
    enum nss_status status = internal_setent (_PATH_VARDB "group.db", &state);
    if (status != NSS_STATUS_SUCCESS)
      {
        *errnop = errno;
        return status;
      }
  
    const struct nss_db_header *header = state.header;
    int i;
    for (i = 0; i < header->ndbs; ++i)
      if (header->dbs[i].id == ':')
        break;
    if (i == header->ndbs)
      {
        status = NSS_STATUS_UNAVAIL;
        goto out;
      }
  
    const stridx_t *hashtable
      = (const stridx_t *) ((const char *) header
  			  + header->dbs[i].hashoffset);
    const char *valstrtab = (const char *) header + header->valstroffset;
    size_t userlen = strlen (user);
    uint32_t hashval = __hash_string (user);
    size_t hidx = hashval % header->dbs[i].hashsize;
    size_t hval2 = 1 + hashval % (header->dbs[i].hashsize - 2);
  
    gid_t *groups = *groupsp;
  
    status = NSS_STATUS_NOTFOUND;
    while (hashtable[hidx] != ~((stridx_t) 0))
      {
        const char *valstr = valstrtab + hashtable[hidx];
        while (isblank (*valstr))
  	++valstr;
  
        if (strncmp (valstr, user, userlen) == 0 && isblank (valstr[userlen]))
  	{
  	  valstr += userlen + 1;
  	  while (isblank (*valstr))
  	    ++valstr;
  
  	  while (*valstr != '\0')
  	    {
  	      errno = 0;
  	      char *endp;
  	      unsigned long int n = strtoul (valstr, &endp, 10);
  	      if (*endp != ',' && *endp != '\0')
  		break;
  	      valstr = *endp == '\0' ? endp : endp + 1;
  
  	      if (n != ULONG_MAX || errno != ERANGE)
  		{
  		  /* Insert the group.  */
  		  if (*start == *size)
  		    {
  		      /* Need a bigger buffer.  */
  		      if (limit > 0 && *size == limit)
  			{
  			  /* We reached the maximum.  */
  			  status = NSS_STATUS_SUCCESS;
  			  goto out;
  			}
  
  		      long int newsize;
  		      if (limit <= 0)
  			newsize = 2 * *size;
  		      else
  			newsize = MIN (limit, 2 * *size);
  
  		      gid_t *newgroups = realloc (groups,
  						  newsize * sizeof (*groups));
  		      if (newgroups == NULL)
  			{
  			  *errnop = ENOMEM;
  			  status = NSS_STATUS_TRYAGAIN;
  			  goto out;
  			}
  
  		      *groupsp = groups = newgroups;
  		      *size = newsize;
  		    }
  
  		  groups[*start] = n;
  		  *start += 1;
  		}
  	    }
  
  	  status = NSS_STATUS_SUCCESS;
  	  break;
  	}
  
        if ((hidx += hval2) >= header->dbs[i].hashsize)
  	hidx -= header->dbs[i].hashsize;
      }
  
   out:
    internal_endent (&state);
  
    return status;
  }
  