Add initgroups lookups to nss_db

1 files changed, 138 insertions, 0 deletions

diff --git a/nss/nss_db/db-initgroups.c b/nss/nss_db/db-initgroups.c
new file mode 100644
index 0000000..aa8163b
--- /dev/null
+++ b/nss/nss_db/db-initgroups.c
@@ -0,0 +1,138 @@
+/* Initgroups handling in nss_db module.
+   Copyright (C) 2011 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,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <ctype.h>
+#include <errno.h>
+#include <grp.h>
+#include <paths.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;
+}