--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/extensions/acl_wl/aw_tree.c	Mon Jan 25 19:07:29 2010 +0900
@@ -0,0 +1,412 @@
+/*********************************************************************************************************
+* Software License Agreement (BSD License)                                                               *
+* Author: Sebastien Decugis <sdecugis@nict.go.jp>							 *
+*													 *
+* Copyright (c) 2009, WIDE Project and NICT								 *
+* All rights reserved.											 *
+* 													 *
+* Redistribution and use of this software in source and binary forms, with or without modification, are  *
+* permitted provided that the following conditions are met:						 *
+* 													 *
+* * Redistributions of source code must retain the above 						 *
+*   copyright notice, this list of conditions and the 							 *
+*   following disclaimer.										 *
+*    													 *
+* * Redistributions in binary form must reproduce the above 						 *
+*   copyright notice, this list of conditions and the 							 *
+*   following disclaimer in the documentation and/or other						 *
+*   materials provided with the distribution.								 *
+* 													 *
+* * Neither the name of the WIDE Project or NICT nor the 						 *
+*   names of its contributors may be used to endorse or 						 *
+*   promote products derived from this software without 						 *
+*   specific prior written permission of WIDE Project and 						 *
+*   NICT.												 *
+* 													 *
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED *
+* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *
+* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR *
+* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 	 *
+* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 	 *
+* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR *
+* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF   *
+* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.								 *
+*********************************************************************************************************/
+
+#include "acl_wl.h"
+
+/* The configuration simply contains the allowed fqdn and/or domains (*.example.net)
+ * It is represented similarly to the DNS tree:
+ *              (root)--___
+ *              /    \     \
+ *            tld1  tld2   (tld3...)
+ *             /      |
+ *          label1   label2
+ *                    /   \
+ *                 lbl21 lbl22
+ *                  /       \
+ *               lbl211      *
+ *
+ * This tree would whitelist:
+ *   - label1.tld1
+ *   - lbl211.lbl21.label2.tld2
+ *   - *.lbl22.label2.tld2
+ *
+ * The functions to add and search the tree are in aw_tree.c.
+ *
+ */
+ 
+/* Maximum depth of the tree. We set a static size to avoid dynamic allocations. We report an error if this is not sufficient. */
+#define AW_TREE_MAXDEPTH 10
+
+/* An element of the tree */
+struct tree_item {
+	struct fd_list	chain;		/* Link to elements at the same level. Ordered alphabetically. */
+	struct fd_list	children;	/* Sentinel for the subtree. */
+	char *		str;	/* the \0 terminated label, or NULL if it is a generic container ("*") */
+	int		flags;	/* PI_SEC_* flags */
+	int		leaf;	/* true if this item can be a leaf of the tree */
+};
+
+/* The root of the tree */
+static struct fd_list tree_root = FD_LIST_INITIALIZER(tree_root);
+
+/* Note: we don't need to lock, since we add only when parsing the conf, and then read only */
+
+
+/* The parsed name */
+struct split_name {
+	struct {
+		char * str;	/* start of this label */
+		size_t len;	/* length of this label. It does not include the final "." or "\0" */
+	}   label[AW_TREE_MAXDEPTH];
+	int last_lbl;	/* idx of last label defined */
+};
+
+/* The following function explodes a name into a split_name structure */
+static int parse_name(char * name, struct split_name * result)
+{
+	int i, l, prev_offset;
+	char * c;
+	
+	TRACE_ENTRY("%p %p", name, result);
+	
+	/* First, initialize the result array */
+	memset(result, 0, sizeof(struct split_name));
+	result->label[0].str = name;
+	l = 0; prev_offset = 0;
+	
+	for (i=0; name[i] != '\0'; i++) {
+		if (name[i]=='.') {
+			l++;
+			CHECK_PARAMS( l < AW_TREE_MAXDEPTH );
+			
+			/* The previous label is complete, write its size */
+			result->label[l - 1].len = i - prev_offset;
+			prev_offset = i + 1;
+			
+			/* Write the start of the new label */
+			result->label[l].str = name + i + 1;
+		}
+	}
+	
+	/* Finally, write the size of the last label */
+	result->label[l].len = i - prev_offset;
+	
+	result->last_lbl = l;
+	
+#if 0
+	fd_log_debug("Parsed name %s as:\n", name);
+	for (i=0; i<=l; i++)
+		fd_log_debug("  str[%d] len: %d, v:%.*s\n", i, result->label[i].len, result->label[i].len, result->label[i].str);
+#endif /* 0 */
+	return 0;
+}
+
+/* Create a new tree_item structure */
+static struct tree_item * new_ti(char * str, size_t len, int flags, int leaf)
+{
+	struct tree_item * ti;
+	char * s = NULL;
+	
+	TRACE_ENTRY("%p %d %x", str, len, flags);
+	
+	if (str) {
+		CHECK_MALLOC_DO(s = malloc(len + 1), return NULL);
+		memcpy(s, str, len);
+		s[len] = '\0';
+	}
+	
+	CHECK_MALLOC_DO( ti = malloc(sizeof(struct tree_item)), {free(s); return NULL; } );
+	memset(ti, 0, sizeof(struct tree_item));
+	
+	fd_list_init(&ti->chain, ti);
+	fd_list_init(&ti->children, ti);
+	ti->str = s;
+	ti->flags = flags;
+	ti->leaf = leaf;
+	
+	return ti;
+}
+
+/* Recursively delete a subtree */
+static void delete_tree(struct fd_list * senti)
+{
+	while (!FD_IS_LIST_EMPTY(senti)) {
+		struct tree_item * ti = (struct tree_item *)(senti->next);
+		
+		/* Delete recursively its children first */
+		delete_tree(&ti->children);
+		
+		/* Now, unlink from the sentinel list */
+		fd_list_unlink(&ti->chain);
+		
+		/* destroy this tree item */
+		free(ti->str);
+		free(ti);
+	}
+}
+
+/* Top-level destroy function */
+void aw_tree_destroy(void)
+{
+	delete_tree(&tree_root);
+}
+
+/* Display the content of a subtree */
+static void tree_dump(struct fd_list * sub, int indent)
+{
+	struct fd_list * li;
+	for (li = sub->next; li != sub; li = li->next) {
+		struct tree_item * ti = (struct tree_item *)li;
+		fd_log_debug("%*s%s", indent * 2, "", ti->str?:"*");
+		if (ti->leaf)
+			fd_log_debug(" (flag:%x)", ti->flags);
+		fd_log_debug("\n");
+		tree_dump(&ti->children, indent + 1);
+	}
+}
+
+/* Top-level function */
+void aw_tree_dump(void)
+{
+	fd_log_debug("[acl_wl] tree dump:\n(root)\n");
+	tree_dump(&tree_root, 1);
+	fd_log_debug("[acl_wl] end of dump\n");
+}
+
+/* Function to add a new entry in the tree */
+int aw_tree_add(char * name, int flags)
+{
+	struct split_name sn;
+	struct tree_item * ti;
+	struct fd_list * li, *senti;
+	int lbl, found;
+	
+	TRACE_ENTRY("%p %x", name, flags);
+	CHECK_PARAMS(name && *name);
+	
+	CHECK_FCT_DO( parse_name(name, &sn), 
+		{ 
+			fd_log_debug("The name '%s' contains too many labels, try a generic (*) or recompile with bigger AW_TREE_MAXDEPTH value (cur: %d)\n", name, AW_TREE_MAXDEPTH); 
+			return EINVAL; 
+		} );
+		
+	senti = &tree_root;
+	
+	for (lbl = sn.last_lbl; lbl > 0; lbl--) {
+		/* Check if the list is empty, we can directly create the new entry */
+		if (FD_IS_LIST_EMPTY(senti)) {
+			CHECK_MALLOC( ti = new_ti(sn.label[lbl].str, sn.label[lbl].len, 0, 0 /* flags are only set in the terminals */) );
+			/* Insert this label in the sentinel sublist */
+			fd_list_insert_after(senti, &ti->chain);
+			/* Update the sentinel */
+			senti = &ti->children;
+			/* loop to the next label */
+			continue;
+		}
+		
+		/* Check if we have a '*' element already that overlapses */
+		ti = (struct tree_item *)(senti->next);
+		if (ti->str == NULL) {
+			fd_log_debug("[acl_wl] Warning: entry '%s' is superseeded by a generic entry at level %d, ignoring.\n", name, lbl);
+			return 0;
+		}
+		
+		/* Search this label in the ordered list */
+		found = 0;
+		for (li = senti->next; li != senti; li=li->next) {
+			int cmp, len;
+			ti = (struct tree_item *)li;
+			
+			cmp = strncasecmp(ti->str, sn.label[lbl].str, sn.label[lbl].len);
+			if (cmp > 0)
+				break;	/* the new label must be inserted before li */
+			if (cmp < 0)
+				continue;
+			
+			/* Check the lengths */
+			len = strlen(ti->str);
+			if (len > sn.label[lbl].len)
+				break;	/* the new label must be inserted before li */
+			if (len < sn.label[lbl].len)
+				continue;
+			
+			/* We already had this label */
+			found = 1;
+			senti = &ti->children;
+			break;
+		}
+		
+		if (found)
+			continue;
+		
+		/* Otherwise, we have to create a new ti, and add it before li */
+		CHECK_MALLOC( ti = new_ti(sn.label[lbl].str, sn.label[lbl].len, 0, 0 /* flags are only set in the terminals */) );
+		/* Insert this label in the sentinel sublist */
+		fd_list_insert_before(li, &ti->chain);
+		/* Update the sentinel */
+		senti = &ti->children;
+	}
+	
+	ti = NULL;
+	li = senti;
+	
+	/* At this point, senti points to the list where we are supposed to insert our last label. */
+	if (sn.label[0].str[0] == '*') {
+		if (!FD_IS_LIST_EMPTY(senti)) {
+			fd_log_debug("[acl_wl] Warning: entry '%s' overwrites previous more detailed entries, these are deleted.\n", name);
+			delete_tree(senti);
+		}
+		
+		/* Create the new entry */
+		CHECK_MALLOC( ti = new_ti(NULL, 0, flags, 1) );
+	} else {
+		if (!FD_IS_LIST_EMPTY(senti)) {
+			/* Check we don't have a '*' entry already */
+			ti = (struct tree_item *)(senti->next);
+			if (ti->str == NULL) {
+				fd_log_debug("[acl_wl] Warning: entry '%s' is superseeded by a generic entry at level 0, ignoring.\n", name);
+				return 0;
+			}
+			
+			/* Search the place for the new label */
+			for (li = senti->next; li != senti; li=li->next) {
+				int cmp, len;
+				ti = (struct tree_item *)li;
+
+				cmp = strncasecmp(ti->str, sn.label[0].str, sn.label[0].len);
+				if (cmp > 0)
+					break;	/* the new label must be inserted before li */
+				if (cmp < 0)
+					continue;
+
+				/* Check the lengths */
+				len = strlen(ti->str);
+				if (len > sn.label[0].len)
+					break;	/* the new label must be inserted before li */
+				if (len < sn.label[0].len)
+					continue;
+
+				/* We already had this label */
+				if (ti->leaf) {
+					fd_log_debug("[acl_wl] Warning: entry '%s' is duplicated, merging the flags.\n", name);
+					ti->flags |= flags;
+					return 0;
+				} else {
+					/* Just mark this entry as a valid leaf also */
+					ti->leaf = 1;
+					ti->flags = flags;
+					return 0;
+				}
+			}
+		}
+		
+		/* Create the new entry */
+		CHECK_MALLOC( ti = new_ti(sn.label[0].str, sn.label[0].len, flags, 1) );
+	}
+	
+	/* The new label is "ti", it is inserted before "li" */
+	fd_list_insert_before(li, &ti->chain);
+	
+	/* Done! */
+	return 0;
+}
+
+/* Search in the tree. On return, *result =  -1: not found; >=0: found with PI_SEC_* flags */
+int aw_tree_lookup(char * name, int * result)
+{
+	struct split_name sn;
+	int lbl, found;
+	struct tree_item * ti;
+	struct fd_list * senti, *li;
+	
+	TRACE_ENTRY("%p %p", name, result);
+	CHECK_PARAMS(name && result);
+	
+	/* Initialize */
+	*result = -1;
+	
+	/* Parse the name into labels */
+	CHECK_FCT_DO( parse_name(name, &sn), 
+		{ 
+			TRACE_DEBUG(INFO, "Too many labels in this name, it cannot be found in the tree, skipping."); 
+			return 0;
+		} );
+	
+	senti = &tree_root;
+	
+	for (lbl = sn.last_lbl; lbl >= 0; lbl--) {
+		/* Check if the list is empty, we can directly return */
+		if (FD_IS_LIST_EMPTY(senti)) {
+			/* The item is not found */
+			return 0;
+		}
+		
+		/* Check if we have a '*' element */
+		ti = (struct tree_item *)(senti->next);
+		if (ti->str == NULL) {
+			TRACE_DEBUG(FULL, "[acl_wl] %s matched at level %d with a generic entry.", name, lbl);
+			*result = ti->flags;
+			return 0;
+		}
+
+		/* Search this label in the ordered list */
+		found = 0;
+		for (li = senti->next; li != senti; li=li->next) {
+			int cmp, len;
+			ti = (struct tree_item *)li;
+			
+			cmp = strncasecmp(ti->str, sn.label[lbl].str, sn.label[lbl].len);
+			if (cmp > 0)
+				return 0;	/* the label was not found */
+			if (cmp < 0)
+				continue;
+			
+			/* Check the lengths */
+			len = strlen(ti->str);
+			if (len > sn.label[lbl].len)
+				return 0;	/* the label was not found */
+			if (len < sn.label[lbl].len)
+				continue;
+			
+			/* We found the label */
+			found = 1;
+			senti = &ti->children;
+			break;
+		}
+		
+		if (!found)
+			return 0; /* label not found */
+		
+		/* otherwise, continue, sentinel has been updated */
+	}
+	
+	/* At the end, ti points to the correct leaf */
+	if (!ti->leaf)
+		return 0;
+	
+	TRACE_DEBUG(FULL, "[acl_wl] %s matched exactly.", name);
+	*result = ti->flags;
+	return 0;
+}