new files for general aliasing

servers/slapd/back-ldbm/alias.c

+/*
+ * Copyright (c) 1998 Will Ballantyne, ITSD, Government of BC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and that due credit is given
+ * to ITSD, Government of BC. The name of ITSD
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission. This software
+ * is provided ``as is'' without express or implied warranty.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include "slap.h"
+#include "back-ldbm.h"
+
+extern Attribute	*attr_find();
+
+/*
+ * given an alias object, dereference it to its end point.
+ */
+Entry *derefAlias ( Backend     *be,
+		    Connection	*conn,
+		    Operation	*op,
+		    Entry       *e
+		    )
+{
+  struct ldbminfo	*li = (struct ldbminfo *) be->be_private;
+  Attribute *a;
+  ID        id;
+  int       depth;
+  char      **pastAliases;
+
+  Debug( LDAP_DEBUG_TRACE, 
+	 "<= checking for alias for dn %s\n", e->e_dn, 0, 0 );
+
+  /*
+   * try to deref fully, up to a maximum depth.  If the max depth exceeded
+   * then send an error
+   */
+  for ( depth = 0;
+	( ( a = attr_find( e->e_attrs, "aliasedobjectname" ) ) != NULL) &&
+	  ( depth < be->be_maxDerefDepth );
+	++depth) {
+
+    /* 
+     * make sure there is a defined aliasedobjectname.  
+     * can only have one value so just use first value (0) in the attr list. 
+     */	    
+    if (a->a_vals[0] && a->a_vals[0]->bv_val) {
+      char *newDN, *oldDN;
+
+      Debug( LDAP_DEBUG_TRACE, "<= %s is an alias for %s\n", 
+	     e->e_dn, a->a_vals[0]->bv_val, 0 );
+      newDN = strdup (a->a_vals[0]->bv_val);
+      oldDN = strdup (e->e_dn);
+
+	/* free reader lock */
+	cache_return_entry_r( &li->li_cache, e );
+	e = NULL;
+
+      /*
+       * ok, so what happens if there is an alias in the DN of a dereferenced
+       * alias object?  
+       */
+      if ( (id = dn2id( be, newDN )) == NOID ||
+	   (e = id2entry_r( be, id )) == NULL ) {
+
+	/* could not deref return error  */
+	Debug( LDAP_DEBUG_TRACE, 
+	       "<= %s is a dangling alias to %s\n", 
+	       oldDN, newDN, 0 );
+	send_ldap_result( conn, op, LDAP_ALIAS_PROBLEM, "",
+			  "Dangling Alias" );
+      }
+      free (newDN);
+      free (oldDN);
+    }
+    else {
+      /*
+       * there was an aliasedobjectname defined but no data.
+       * this can't happen, right?
+       */
+	Debug( LDAP_DEBUG_TRACE, 
+	       "<= %s has no data in aliasedobjectname attribute\n", 
+	       e->e_dn, 0, 0 );
+	send_ldap_result( conn, op, LDAP_ALIAS_PROBLEM, "",
+			  "Alias missing aliasedobjectname" );
+    }
+  }
+
+  /*
+   * warn if we pulled out due to exceeding the maximum deref depth
+   */
+  if ( depth >= be->be_maxDerefDepth ) {
+    Debug( LDAP_DEBUG_TRACE, 
+	   "<= %s exceeded maximum deref depth %d\n", 
+	   e->e_dn, be->be_maxDerefDepth, 0 );
+    send_ldap_result( conn, op, LDAP_ALIAS_PROBLEM, "",
+			"Maximum alias dereference depth exceeded" );
+  }
+
+  return e;
+}
+
+/*
+ * given a DN fully deref it and return the real DN or original DN if it fails
+ */
+char *derefDN ( Backend     *be,
+                Connection  *conn,
+                Operation   *op,
+                char        *dn
+)
+{
+  struct ldbminfo	*li = (struct ldbminfo *) be->be_private;
+  char 	*matched;
+  char 	*newDN;
+  int	depth;
+  Entry 	*e = NULL;
+  
+
+  Debug( LDAP_DEBUG_TRACE, 
+	 "<= dereferencing dn %s\n", 
+	 dn, 0, 0 );
+  
+  newDN = strdup ( dn );
+  
+  /* while we don't have a matched dn, deref the DN */
+  for ( depth = 0;
+	( (e = dn2entry_r( be, newDN, &matched )) == NULL) &&
+	  (depth < be->be_maxDerefDepth);
+	++depth ) {
+    
+    if (*matched) {	
+      char *submatch;
+      
+	if( e != NULL ) {
+		/* free reader lock */
+		cache_return_entry_r( &li->li_cache, e );
+		e = NULL;
+	}
+
+      /* 
+       * make sure there actually is an entry for the matched part 
+       */
+      if ( (e = dn2entry_r( be, matched, &submatch )) != NULL) {
+	char  *remainder; /* part before the aliased part */
+	Entry *newE;
+	int  rlen = strlen(newDN) - strlen(matched);
+	
+	Debug( LDAP_DEBUG_TRACE, 
+	       "<= matched %s\n", 
+	       matched, 0, 0 );
+	
+	remainder = ch_malloc (rlen + 1);
+	strncpy ( remainder, newDN, rlen );
+	remainder[rlen]	= '\0';
+	
+	Debug( LDAP_DEBUG_TRACE, 
+	       "<= remainder %s\n",
+	       remainder, 0, 0 );
+	
+	if ((newE = derefAlias (be, conn, op, e)) == NULL) {
+	  free (matched);
+	  free (newDN);
+	  break; /*  no associated entry, dont deref */
+	}
+	else {
+
+	  Debug( LDAP_DEBUG_TRACE, 
+		 "<= l&g we have %s vs %s \n",
+		 matched, newE->e_dn, 0 );
+
+	  if (!strcasecmp (matched, newE->e_dn)) {
+	    /* newDN same as old so not an alias, no need to go further */
+	    free (newDN);
+	    free (matched);
+	    break;
+	  }
+
+	  /* 
+	   * we have dereferenced the aliased part so put
+	   * the new dn together
+	   */
+	  free (newDN);
+	  free (matched);
+	  
+	  newDN = ch_malloc (strlen(e->e_dn) + rlen + 1);
+	  strcpy (newDN, remainder);
+	  strcat (newDN, e->e_dn);
+	  Debug( LDAP_DEBUG_TRACE, "<= expanded to %s\n", newDN, 0, 0 );
+	}
+      }
+      else {
+	break; /* there was no entry for the matched part */
+      }
+    }
+    else {
+      break; /* there was no matched part */
+    }
+
+	if( e != NULL ) {
+		/* free reader lock */
+		cache_return_entry_r( &li->li_cache, e );
+		e = NULL;
+	}
+  }
+  
+  if( e != NULL ) {
+	/* free reader lock */
+	cache_return_entry_r( &li->li_cache, e );
+	e = NULL;
+  }
+
+  /*
+   * the final part of the DN might be an alias 
+   * so try to dereference it.
+   */
+
+  if ( (e = dn2entry_r( be, newDN, &matched )) != NULL) {
+    if ((e = derefAlias (be, conn, op, e)) != NULL) {
+      free (newDN);
+      newDN = strdup (e->e_dn);
+    }
+  }
+  
+  /*
+   * warn if we exceeded the max depth as the resulting DN may not be dereferenced
+   */
+  if (depth >= be->be_maxDerefDepth) {
+    Debug( LDAP_DEBUG_TRACE, 
+	   "<= max deref depth exceeded in derefDN for %s, result %s\n", 
+	   dn, newDN, 0 );
+    send_ldap_result( conn, op, LDAP_ALIAS_PROBLEM, "",
+		      "Maximum alias dereference depth exceeded for base" );
+  }
+  
+  Debug( LDAP_DEBUG_TRACE, "<= returning deref DN of  %s\n", newDN, 0, 0 ); 
+
+  return newDN;
+}

servers/slapd/suffixalias.c

+/*
+ * Copyright (c) 1998 Will Ballantyne, ITSD, Government of BC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and that due credit is given
+ * to ITSD, Government of BC. The name of ITSD
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission. This software
+ * is provided ``as is'' without express or implied warranty.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include "slap.h"
+
+/* 
+ * given a dn (or root part), return an aliased dn if any of the 
+ * alias suffixes match
+ */
+char *suffixAlias ( dn, op, be )
+	char *dn;
+	Operation *op;
+	Backend *be;
+{
+	int 	i, dnLength;
+
+	dnLength = strlen ( dn );
+        op->o_suffix = NULL;
+        op->o_suffixAliased = NULL;
+        for ( i = 0;
+              be->be_suffixAlias != NULL && be->be_suffixAlias[i] != NULL;
+              i += 2) {
+                int aliasLength = strlen (be->be_suffixAlias[i]);
+                if (aliasLength > dnLength) {
+                        continue;
+                }
+
+                if (!strcasecmp(be->be_suffixAlias[i], 
+				dn + (dnLength - aliasLength))) {
+                        char *oldDN = dn;
+                        op->o_suffixAliased = strdup ( be->be_suffixAlias[i] );
+                        dn = ch_malloc ( (dnLength - aliasLength) +
+                                          strlen (be->be_suffixAlias[ i+1 ]) + 1);
+                        strncpy (dn, oldDN, dnLength - aliasLength);
+                        strcpy  (dn + (dnLength - aliasLength), be->be_suffixAlias[ i+1 ]);
+                        op->o_suffix = strdup (dn);
+                        Debug( LDAP_DEBUG_ARGS, "ALIAS: converted %s to %s", oldDN, dn, 0);
+                        free (oldDN);
+			break;
+		}
+	}
+	return dn;
+}