ippool: Add IP pool layer

This is based on Guillaume Zajac intial IP pool patches.

1 files changed, 289 insertions, 0 deletions

diff --git a/src/ippool.c b/src/ippool.c
new file mode 100644
index 00000000..085d06c5
--- /dev/null
+++ b/src/ippool.c
@@ -0,0 +1,289 @@
+/*
+ *
+ *  Connection Manager
+ *
+ *  Copyright (C) 2007-2012  Intel Corporation. All rights reserved.
+ *  Copyright (C) 2012  BMW Car IT GmbH. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <getopt.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/errno.h>
+#include <sys/socket.h>
+
+#include "connman.h"
+
+struct connman_ippool {
+	unsigned int refcount;
+
+	uint32_t block;
+
+	char *gateway;
+	char *broadcast;
+	char *start_ip;
+	char *end_ip;
+	char *subnet_mask;
+};
+
+static GHashTable *hash_pool;
+static uint32_t last_block;
+static uint32_t block_16_bits;
+static uint32_t block_20_bits;
+static uint32_t block_24_bits;
+static uint32_t subnet_mask_24;
+
+struct connman_ippool *
+__connman_ippool_ref_debug(struct connman_ippool *pool,
+				const char *file, int line, const char *caller)
+{
+	DBG("%p ref %d by %s:%d:%s()", pool, pool->refcount + 1,
+		file, line, caller);
+
+	__sync_fetch_and_add(&pool->refcount, 1);
+
+	return pool;
+}
+
+void __connman_ippool_unref_debug(struct connman_ippool *pool,
+				const char *file, int line, const char *caller)
+{
+	if (pool == NULL)
+		return;
+
+	DBG("%p ref %d by %s:%d:%s()", pool, pool->refcount - 1,
+		file, line, caller);
+
+	if (__sync_fetch_and_sub(&pool->refcount, 1) != 1)
+		return;
+
+	g_hash_table_remove(hash_pool, GUINT_TO_POINTER(pool->block));
+}
+
+static char *get_ip(uint32_t ip)
+{
+	struct in_addr addr;
+
+	addr.s_addr = htonl(ip);
+
+	return g_strdup(inet_ntoa(addr));
+}
+
+static uint32_t next_block(uint32_t block)
+{
+	uint32_t next;
+
+	/*
+	 * Return the next IP block within the private IP range
+	 *
+	 * 16-bit block 192.168.0.0 – 192.168.255.255
+	 * 20-bit block  172.16.0.0 –  172.31.255.255
+	 * 24-bit block    10.0.0.0 –  10.255.255.255
+	 */
+
+	next = (block & 0x0000ff00) >> 8;
+	next += 1;
+
+	if (next == 255) {
+		if ((block & 0xffffff00) == block_16_bits) {
+			/*
+			 * Reached the end of the 16 bit block, switch
+			 * to the 20-bit block.
+			 */
+			return block_20_bits;
+		}
+
+		if ((block & 0xffff0000) >= block_20_bits) {
+			next = (block & 0x00ff0000) >> 16;
+			if (next >= 16 && next < 32)
+				next += 1;
+
+			if (next == 32) {
+				/*
+				 * Reached the end of the 20 bit
+				 * block, switch to the 24-bit block.
+				 */
+				return block_24_bits;
+			}
+
+			return (block & 0xff000000) |
+				((next << 16) & 0x00ff0000);
+		}
+
+		if ((block & 0xff000000) == block_24_bits) {
+			next = (block & 0x00ff0000) >> 16;
+			if (next < 255)
+				next += 1;
+
+			if (next == 255) {
+				/*
+				 * Reached the end of the 24 bit
+				 * block, switch to the 16-bit block.
+				 */
+				return block_16_bits;
+			}
+
+			return (block & 0xff000000) |
+				((next << 16) & 0x00ff0000);
+		}
+	}
+
+	return (block & 0xffff0000) | ((next << 8) & 0x0000ff00);
+}
+
+static uint32_t find_free_block()
+{
+	struct connman_ippool *pool;
+	uint32_t start;
+	uint32_t block;
+
+	if (last_block == 0)
+		return block_16_bits;
+
+	/*
+	 * Instead starting always from the 16 bit block, we start
+	 * from the last assigned block. This is a simple optimimazion
+	 * for the case where a lot of blocks have been assigned, e.g.
+	 * the first half of the private IP pool is in use and a new
+	 * we need to find a new block.
+	 *
+	 * To only thing we have to make sure is that we terminated if
+	 * there is no block left.
+	 */
+	start = last_block;
+
+	block = next_block(start);
+	while (start != block) {
+		block = next_block(block);
+
+		pool = g_hash_table_lookup(hash_pool, GUINT_TO_POINTER(block));
+		if (pool != NULL)
+			continue;
+
+		return block;
+	}
+
+	return 0;
+}
+
+struct connman_ippool *__connman_ippool_create(unsigned int start,
+						unsigned int range)
+{
+	struct connman_ippool *pool;
+	uint32_t block;
+
+	/*
+	 * The range is at max 255 and we don't support overlapping
+	 * blocks.
+	 */
+	if (start + range > 254)
+		return NULL;
+
+	block = find_free_block();
+	if (block == 0)
+		return NULL;
+
+	pool = g_try_new0(struct connman_ippool, 1);
+	if (pool == NULL)
+		return NULL;
+
+	pool->refcount = 1;
+	pool->block = block;
+
+	last_block = block;
+
+	if (range == 0)
+		range = 1;
+
+	pool->gateway = get_ip(block + 1);
+	pool->broadcast = get_ip(block + 255);
+	pool->subnet_mask = get_ip(subnet_mask_24);
+	pool->start_ip = get_ip(block + start);
+	pool->end_ip = get_ip(block + start + range);
+
+	g_hash_table_insert(hash_pool, GUINT_TO_POINTER(pool->block), pool);
+
+	return pool;
+}
+
+const char *__connman_ippool_get_gateway(struct connman_ippool *pool)
+{
+	return pool->gateway;
+}
+
+const char *__connman_ippool_get_broadcast(struct connman_ippool *pool)
+{
+	return pool->broadcast;
+}
+
+const char *__connman_ippool_get_start_ip(struct connman_ippool *pool)
+{
+	return pool->start_ip;
+}
+
+const char *__connman_ippool_get_end_ip(struct connman_ippool *pool)
+{
+	return pool->end_ip;
+}
+
+const char *__connman_ippool_get_subnet_mask(struct connman_ippool *pool)
+{
+	return pool->subnet_mask;
+}
+
+static void pool_free(gpointer data)
+{
+	struct connman_ippool *pool = data;
+
+	g_free(pool->gateway);
+	g_free(pool->broadcast);
+	g_free(pool->start_ip);
+	g_free(pool->end_ip);
+	g_free(pool->subnet_mask);
+
+	g_free(pool);
+}
+
+int __connman_ippool_init(void)
+{
+	DBG("");
+
+	/* We start at 254 by default to avoid common addresses */
+	block_16_bits = ntohl(inet_addr("192.168.254.0"));
+	block_20_bits = ntohl(inet_addr("172.16.0.0"));
+	block_24_bits = ntohl(inet_addr("10.0.0.0"));
+	subnet_mask_24 = ntohl(inet_addr("255.255.255.0"));
+
+	hash_pool = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL,
+						pool_free);
+
+	return 0;
+}
+
+void __connman_ippool_cleanup(void)
+{
+	DBG("");
+
+	g_hash_table_destroy(hash_pool);
+	hash_pool = NULL;
+}