// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Routing table test
 * Copyright (C) 2012 OSR.
 *
 * This file is part of Quagga
 */

#include <zebra.h>
#include "printfrr.h"
#include "prefix.h"
#include "table.h"

/*
 * test_node_t
 *
 * Information that is kept for each node in the radix tree.
 */
typedef struct test_node_t_ {

	/*
	 * Human readable representation of the string. Allocated using
	 * malloc()/dup().
	 */
	char *prefix_str;
} test_node_t;

struct event_loop *master;

/*
 * add_node
 *
 * Add the given prefix (passed in as a string) to the given table.
 */
static void add_node(struct route_table *table, const char *prefix_str)
{
	struct prefix_ipv4 p;
	test_node_t *node;
	struct route_node *rn;

	assert(prefix_str);

	if (str2prefix_ipv4(prefix_str, &p) <= 0) {
		assert(0);
	}

	rn = route_node_get(table, (struct prefix *)&p);
	if (rn->info) {
		assert(0);
		return;
	}

	node = malloc(sizeof(test_node_t));
	assert(node);
	node->prefix_str = strdup(prefix_str);
	assert(node->prefix_str);
	rn->info = node;
}

/*
 * add_nodes
 *
 * Convenience function to add a bunch of nodes together.
 *
 * The arguments must be prefixes in string format, with a NULL as the
 * last argument.
 */
static void add_nodes(struct route_table *table, ...)
{
	va_list arglist;
	char *prefix;

	va_start(arglist, table);

	prefix = va_arg(arglist, char *);
	while (prefix) {
		add_node(table, prefix);
		prefix = va_arg(arglist, char *);
	}

	va_end(arglist);
}

/*
 * print_subtree
 *
 * Recursive function to print a route node and its children.
 *
 * @see print_table
 */
static void print_subtree(struct route_node *rn, const char *legend,
			  int indent_level)
{
	int i;

	/*
	 * Print this node first.
	 */
	for (i = 0; i < indent_level; i++) {
		printf("  ");
	}

	printfrr("%s: %pFX", legend, &rn->p);
	if (!rn->info) {
		printf(" (internal)");
	}
	printf("\n");
	if (rn->l_left) {
		print_subtree(rn->l_left, "Left", indent_level + 1);
	}
	if (rn->l_right) {
		print_subtree(rn->l_right, "Right", indent_level + 1);
	}
}

/*
 * print_table
 *
 * Function that prints out the internal structure of a route table.
 */
static void print_table(struct route_table *table)
{
	struct route_node *rn;

	rn = table->top;

	if (!rn) {
		printf("<Empty Table>\n");
		return;
	}

	print_subtree(rn, "Top", 0);
}

/*
 * clear_table
 *
 * Remove all nodes from the given table.
 */
static void clear_table(struct route_table *table)
{
	route_table_iter_t iter;
	struct route_node *rn;
	test_node_t *node;

	route_table_iter_init(&iter, table);

	while ((rn = route_table_iter_next(&iter))) {
		node = rn->info;
		if (!node) {
			continue;
		}
		rn->info = NULL;
		route_unlock_node(rn);
		free(node->prefix_str);
		free(node);
	}

	route_table_iter_cleanup(&iter);

	assert(table->top == NULL);
}

/*
 * verify_next_by_iterating
 *
 * Iterate over the tree to make sure that the first prefix after
 * target_pfx is the expected one. Note that target_pfx may not be
 * present in the tree.
 */
static void verify_next_by_iterating(struct route_table *table,
				     struct prefix *target_pfx,
				     struct prefix *next_pfx)
{
	route_table_iter_t iter;
	struct route_node *rn;

	route_table_iter_init(&iter, table);
	while ((rn = route_table_iter_next(&iter))) {
		if (route_table_prefix_iter_cmp(&rn->p, target_pfx) > 0) {
			assert(!prefix_cmp(&rn->p, next_pfx));
			break;
		}
	}

	if (!rn) {
		assert(!next_pfx);
	}

	route_table_iter_cleanup(&iter);
}

/*
 * verify_next
 *
 * Verifies that route_table_get_next() returns the expected result
 * (result) for the prefix string 'target'.
 */
static void verify_next(struct route_table *table, const char *target,
			const char *next)
{
	struct prefix_ipv4 target_pfx, next_pfx;
	struct route_node *rn;
	char result_buf[PREFIX2STR_BUFFER];

	if (str2prefix_ipv4(target, &target_pfx) <= 0) {
		assert(0);
	}

	rn = route_table_get_next(table, (struct prefix *)&target_pfx);
	if (rn) {
		prefix2str(&rn->p, result_buf, sizeof(result_buf));
	} else {
		snprintf(result_buf, sizeof(result_buf), "(Null)");
	}

	printf("\n");
	print_table(table);
	printf("Verifying successor of %s. Expected: %s, Result: %s\n", target,
	       next ? next : "(Null)", result_buf);

	if (!rn) {
		assert(!next);
		verify_next_by_iterating(table, (struct prefix *)&target_pfx,
					 NULL);
		return;
	}

	assert(next);

	if (str2prefix_ipv4(next, &next_pfx) <= 0) {
		assert(0);
	}

	if (prefix_cmp(&rn->p, (struct prefix *)&next_pfx)) {
		assert(0);
	}
	route_unlock_node(rn);

	verify_next_by_iterating(table, (struct prefix *)&target_pfx,
				 (struct prefix *)&next_pfx);
}

/*
 * test_get_next
 */
static void test_get_next(void)
{
	struct route_table *table;

	printf("\n\nTesting route_table_get_next()\n");
	table = route_table_init();

	/*
	 * Target exists in tree, but has no successor.
	 */
	add_nodes(table, "1.0.1.0/24", NULL);
	verify_next(table, "1.0.1.0/24", NULL);
	clear_table(table);

	/*
	 * Target exists in tree, and there is a node in its left subtree.
	 */
	add_nodes(table, "1.0.1.0/24", "1.0.1.0/25", NULL);
	verify_next(table, "1.0.1.0/24", "1.0.1.0/25");
	clear_table(table);

	/*
	 * Target exists in tree, and there is a node in its right subtree.
	 */
	add_nodes(table, "1.0.1.0/24", "1.0.1.128/25", NULL);
	verify_next(table, "1.0.1.0/24", "1.0.1.128/25");
	clear_table(table);

	/*
	 * Target exists in the tree, next node is outside subtree.
	 */
	add_nodes(table, "1.0.1.0/24", "1.1.0.0/16", NULL);
	verify_next(table, "1.0.1.0/24", "1.1.0.0/16");
	clear_table(table);

	/*
	 * The target node does not exist in the tree for all the test cases
	 * below this point.
	 */

	/*
	 * There is no successor in the tree.
	 */
	add_nodes(table, "1.0.0.0/16", NULL);
	verify_next(table, "1.0.1.0/24", NULL);
	clear_table(table);

	/*
	 * There exists a node that would be in the target's left subtree.
	 */
	add_nodes(table, "1.0.0.0/16", "1.0.1.0/25", NULL);
	verify_next(table, "1.0.1.0/24", "1.0.1.0/25");
	clear_table(table);

	/*
	 * There exists a node would be in the target's right subtree.
	 */
	add_nodes(table, "1.0.0.0/16", "1.0.1.128/25", NULL);
	verify_next(table, "1.0.1.0/24", "1.0.1.128/25");
	clear_table(table);

	/*
	 * A search for the target reaches a node where there are no child
	 * nodes in the direction of the target (left), but the node has a
	 * right child.
	 */
	add_nodes(table, "1.0.0.0/16", "1.0.128.0/17", NULL);
	verify_next(table, "1.0.0.0/17", "1.0.128.0/17");
	clear_table(table);

	/*
	 * A search for the target reaches a node with no children. We have
	 * to go upwards in the tree to find a successor.
	 */
	add_nodes(table, "1.0.0.0/16", "1.0.0.0/24", "1.0.1.0/24",
		  "1.0.128.0/17", NULL);
	verify_next(table, "1.0.1.0/25", "1.0.128.0/17");
	clear_table(table);

	/*
	 * A search for the target reaches a node where neither the node nor
	 * the target prefix contain each other.
	 *
	 * In first case below the node succeeds the target.
	 *
	 * In the second case, the node comes before the target, so we have
	 * to go up the tree looking for a successor.
	 */
	add_nodes(table, "1.0.0.0/16", "1.0.1.0/24", NULL);
	verify_next(table, "1.0.0.0/24", "1.0.1.0/24");
	clear_table(table);

	add_nodes(table, "1.0.0.0/16", "1.0.0.0/24", "1.0.1.0/25",
		  "1.0.128.0/17", NULL);
	verify_next(table, "1.0.1.128/25", "1.0.128.0/17");
	clear_table(table);

	route_table_finish(table);
}

/*
 * verify_prefix_iter_cmp
 */
static void verify_prefix_iter_cmp(const char *p1, const char *p2,
				   int exp_result)
{
	struct prefix_ipv4 p1_pfx, p2_pfx;
	int result;

	if (str2prefix_ipv4(p1, &p1_pfx) <= 0) {
		assert(0);
	}

	if (str2prefix_ipv4(p2, &p2_pfx) <= 0) {
		assert(0);
	}

	result = route_table_prefix_iter_cmp((struct prefix *)&p1_pfx,
					     (struct prefix *)&p2_pfx);

	printf("Verifying cmp(%s, %s) returns %d\n", p1, p2, exp_result);

	assert(exp_result == result);

	/*
	 * Also check the reverse comparison.
	 */
	result = route_table_prefix_iter_cmp((struct prefix *)&p2_pfx,
					     (struct prefix *)&p1_pfx);

	if (exp_result) {
		exp_result = -exp_result;
	}

	printf("Verifying cmp(%s, %s) returns %d\n", p1, p2, exp_result);
	assert(result == exp_result);
}

/*
 * test_prefix_iter_cmp
 *
 * Tests comparison of prefixes according to order of iteration.
 */
static void test_prefix_iter_cmp(void)
{
	printf("\n\nTesting route_table_prefix_iter_cmp()\n");

	verify_prefix_iter_cmp("1.0.0.0/8", "1.0.0.0/8", 0);

	verify_prefix_iter_cmp("1.0.0.0/8", "1.0.0.0/16", -1);

	verify_prefix_iter_cmp("1.0.0.0/16", "1.128.0.0/16", -1);
}

/*
 * verify_iter_with_pause
 *
 * Iterates over a tree using two methods: 'normal' iteration, and an
 * iterator that pauses at each node. Verifies that the two methods
 * yield the same results.
 */
static void verify_iter_with_pause(struct route_table *table)
{
	unsigned long num_nodes;
	struct route_node *rn, *iter_rn;
	route_table_iter_t iter_space;
	route_table_iter_t *iter = &iter_space;

	route_table_iter_init(iter, table);
	num_nodes = 0;

	for (rn = route_top(table); rn; rn = route_next(rn)) {
		num_nodes++;
		route_table_iter_pause(iter);

		assert(iter->current == NULL);
		if (route_table_iter_started(iter)) {
			assert(iter->state == RT_ITER_STATE_PAUSED);
		} else {
			assert(rn == table->top);
			assert(iter->state == RT_ITER_STATE_INIT);
		}

		iter_rn = route_table_iter_next(iter);

		/*
		 * Make sure both iterations return the same node.
		 */
		assert(rn == iter_rn);
	}

	assert(num_nodes == route_table_count(table));

	route_table_iter_pause(iter);
	iter_rn = route_table_iter_next(iter);

	assert(iter_rn == NULL);
	assert(iter->state == RT_ITER_STATE_DONE);

	assert(route_table_iter_next(iter) == NULL);
	assert(iter->state == RT_ITER_STATE_DONE);

	route_table_iter_cleanup(iter);

	print_table(table);
	printf("Verified pausing iteration on tree with %lu nodes\n",
	       num_nodes);
}

/*
 * test_iter_pause
 */
static void test_iter_pause(void)
{
	struct route_table *table;
	int i, num_prefixes;
	const char *prefixes[] = {"1.0.1.0/24", "1.0.1.0/25", "1.0.1.128/25",
				  "1.0.2.0/24", "2.0.0.0/8"};

	num_prefixes = array_size(prefixes);

	printf("\n\nTesting that route_table_iter_pause() works as expected\n");
	table = route_table_init();
	for (i = 0; i < num_prefixes; i++) {
		add_nodes(table, prefixes[i], NULL);
	}

	verify_iter_with_pause(table);

	clear_table(table);
	route_table_finish(table);
}

/*
 * run_tests
 */
static void run_tests(void)
{
	test_prefix_iter_cmp();
	test_get_next();
	test_iter_pause();
}

/*
 * main
 */
int main(void)
{
	run_tests();
}