net: Add ICMPv6 handler

The host will be able to respond to ICMPv6 messages.
An echo-request handler is implemented and it will send
echo-reply when needed.

Change-Id: I08f4703bab5cf3e95d3ae722ebc7a386d22fe17e
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

net/ip/Kconfig.debug

@@ -129,7 +129,14 @@ config NETWORK_IP_STACK_DEBUG_IPV6_DS
 
 config NETWORK_IP_STACK_DEBUG_IPV6_ICMPV6
 	bool "Debug ICMPv6"
-	depends on NETWORKING_WITH_IPV6 || NET_IPV6
+	depends on NETWORKING_WITH_IPV6
+	default n
+	help
+	  Enables ICMPv6 code part to output debug messages
+
+config NETWORK_IP_STACK_DEBUG_ICMPV6
+	bool "Debug ICMPv6"
+	depends on NET_IPV6
 	default n
 	help
 	  Enables ICMPv6 code part to output debug messages

net/yaip/Makefile

@@ -4,3 +4,5 @@ obj-y = net_core.o \
 	net_context.o \
 	nbuf.o \
 	utils.o
+
+obj-$(CONFIG_NET_IPV6) += icmpv6.o

net/yaip/icmpv6.c

@@ -0,0 +1,136 @@
+/** @file
+ * @brief ICMPv6 related functions
+ */
+
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifdef CONFIG_NETWORK_IP_STACK_DEBUG_ICMPV6
+#define SYS_LOG_DOMAIN "net/icmpv6"
+#define NET_DEBUG 1
+#endif
+
+#include <errno.h>
+#include <misc/slist.h>
+#include <net/net_core.h>
+#include <net/nbuf.h>
+#include <net/net_if.h>
+#include <net/net_stats.h>
+#include "net_private.h"
+#include "icmpv6.h"
+
+static sys_slist_t handlers;
+
+void net_icmpv6_register_handler(struct net_icmpv6_handler *handler)
+{
+	sys_slist_prepend(&handlers, &handler->node);
+}
+
+static enum net_verdict handle_echo_request(struct net_buf *buf)
+{
+	/* Note that we send the same data buffers back and just swap
+	 * the addresses etc.
+	 */
+#if NET_DEBUG > 0
+	char out[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx")];
+
+	snprintf(out, sizeof(out),
+		 net_sprint_ipv6_addr(&NET_IPV6_BUF(buf)->dst));
+	NET_DBG("Received Echo Request from %s to %s",
+		net_sprint_ipv6_addr(&NET_IPV6_BUF(buf)->src), out);
+#endif /* NET_DEBUG > 0 */
+
+	if (net_is_ipv6_addr_mcast(&NET_IPV6_BUF(buf)->dst)) {
+		net_ipaddr_copy(&NET_IPV6_BUF(buf)->dst,
+				&NET_IPV6_BUF(buf)->src);
+
+		net_ipaddr_copy(&NET_IPV6_BUF(buf)->src,
+				net_if_ipv6_select_src_addr(net_nbuf_iface(buf),
+						&NET_IPV6_BUF(buf)->dst));
+	} else {
+		struct in6_addr addr;
+
+		net_ipaddr_copy(&addr, &NET_IPV6_BUF(buf)->src);
+		net_ipaddr_copy(&NET_IPV6_BUF(buf)->src,
+				&NET_IPV6_BUF(buf)->dst);
+		net_ipaddr_copy(&NET_IPV6_BUF(buf)->dst, &addr);
+	}
+
+	NET_IPV6_BUF(buf)->hop_limit =
+		net_if_ipv6_get_hop_limit(net_nbuf_iface(buf));
+
+	NET_ICMP_BUF(buf)->type = NET_ICMPV6_ECHO_REPLY;
+	NET_ICMP_BUF(buf)->code = 0;
+	NET_ICMP_BUF(buf)->chksum = 0;
+	NET_ICMP_BUF(buf)->chksum = ~net_calc_chksum_icmpv6(buf);
+
+#if NET_DEBUG > 0
+	snprintf(out, sizeof(out),
+		 net_sprint_ipv6_addr(&NET_IPV6_BUF(buf)->dst));
+	NET_DBG("Sending Echo Reply from %s to %s",
+		net_sprint_ipv6_addr(&NET_IPV6_BUF(buf)->src), out);
+#endif /* NET_DEBUG > 0 */
+
+	if (net_send_data(buf) < 0) {
+		NET_STATS(++net_stats.icmp.drop);
+		return NET_DROP;
+	}
+
+	NET_STATS(++net_stats.icmp.sent);
+
+	return NET_OK;
+}
+
+enum net_verdict net_icmpv6_input(struct net_buf *buf, uint16_t len,
+				  uint8_t type, uint8_t code)
+{
+	sys_snode_t *node;
+	struct net_icmpv6_handler *cb;
+
+	SYS_SLIST_FOR_EACH_NODE(&handlers, node) {
+		cb = (struct net_icmpv6_handler *)node;
+
+		if (!cb) {
+			continue;
+		}
+
+		if (cb->type == type && (cb->code == code || cb->code == 0)) {
+			NET_STATS(++net_stats.icmp.recv);
+			return cb->handler(buf);
+		}
+	}
+
+	return NET_DROP;
+}
+
+static struct net_icmpv6_handler echo_request_handler = {
+	.type = NET_ICMPV6_ECHO_REQUEST,
+	.code = 0,
+	.handler = handle_echo_request,
+};
+
+void net_icmpv6_init(void)
+{
+	static bool is_initialized;
+
+	if (is_initialized) {
+		return;
+	}
+
+	net_icmpv6_register_handler(&echo_request_handler);
+
+	is_initialized = true;
+}

net/yaip/icmpv6.h

@@ -0,0 +1,49 @@
+/** @file
+ @brief ICMPv6 handler
+
+ This is not to be included by the application.
+ */
+
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __ICMPV6_H
+#define __ICMPV6_H
+
+#include <misc/slist.h>
+#include <stdint.h>
+
+#include <net/net_ip.h>
+#include <net/nbuf.h>
+
+#define NET_ICMPV6_ECHO_REQUEST 128
+#define NET_ICMPV6_ECHO_REPLY   129
+
+typedef enum net_verdict (*icmpv6_callback_handler_t)(struct net_buf *buf);
+
+struct net_icmpv6_handler {
+	sys_snode_t node;
+	uint8_t type;
+	uint8_t code;
+	icmpv6_callback_handler_t handler;
+};
+
+void net_icmpv6_register_handler(struct net_icmpv6_handler *handler);
+enum net_verdict net_icmpv6_input(struct net_buf *buf, uint16_t len,
+				  uint8_t type, uint8_t code);
+void net_icmpv6_init(void);
+
+#endif /* __ICMPV6_H */

net/yaip/net_core.c

@@ -41,6 +41,10 @@
 
 #include "net_private.h"
 
+#if defined(CONFIG_NET_IPV6)
+#include "icmpv6.h"
+#endif
+
 /* Stack for the rx fiber.
  */
 #if !defined(CONFIG_NET_RX_STACK_SIZE)
@@ -323,7 +327,9 @@ int net_recv_data(struct net_if *iface, struct net_buf *buf)
 
 static int network_initialization(void)
 {
-
+#if defined(CONFIG_NET_IPV6)
+	net_icmpv6_init();
+#endif
 	return 0;
 }
 

net/yaip/net_private.h

@@ -33,6 +33,11 @@ extern char *net_sprint_ip_addr_buf(uint8_t *ip, int ip_len,
 				    char *buf, int buflen);
 extern uint16_t net_calc_chksum(struct net_buf *buf, uint8_t proto);
 
+static inline uint16_t net_calc_chksum_icmpv6(struct net_buf *buf)
+{
+	return net_calc_chksum(buf, IPPROTO_ICMPV6);
+}
+
 #if NET_DEBUG > 0
 static inline char *net_sprint_ll_addr(uint8_t *ll, uint8_t ll_len)
 {