net: Process received ICMPv4 messages

Call ICMPv4 handler when receiving ICMP v4 packet.
Currently only echo-request msg is handled.

Change-Id: Ib59c65b38f13c484f1842485118dad32fb6a6f36
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

include/net/yaip/net_ip.h

@@ -44,6 +44,7 @@ extern "C" {
 
 /** Protocol numbers from IANA */
 enum ip_protocol {
+	IPPROTO_ICMP = 1,
 	IPPROTO_TCP = 6,
 	IPPROTO_UDP = 17,
 	IPPROTO_ICMPV6 = 58,

net/ip/Kconfig.debug

@@ -141,13 +141,6 @@ config NETWORK_IP_STACK_DEBUG_ICMPV6
 	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
-
 config NETWORK_IP_STACK_DEBUG_ICMPV4
 	bool "Debug ICMPv4"
 	depends on NET_IPV4

net/yaip/Makefile

@@ -6,3 +6,4 @@ obj-y = net_core.o \
 	utils.o
 
 obj-$(CONFIG_NET_IPV6) += icmpv6.o
+obj-$(CONFIG_NET_IPV4) += icmpv4.o

net/yaip/icmpv4.c

@@ -0,0 +1,87 @@
+/** @file
+ * @brief ICMPv4 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_ICMPV4
+#define SYS_LOG_DOMAIN "net/icmpv4"
+#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 "icmpv4.h"
+
+static inline 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.
+	 */
+	struct in_addr addr;
+
+#if NET_DEBUG > 0
+	char out[sizeof("xxx.xxx.xxx.xxx")];
+
+	snprintf(out, sizeof(out),
+		 net_sprint_ipv4_addr(&NET_IPV4_BUF(buf)->dst));
+	NET_DBG("Received Echo Request from %s to %s",
+		net_sprint_ipv4_addr(&NET_IPV4_BUF(buf)->src), out);
+#endif /* NET_DEBUG > 0 */
+
+	net_ipaddr_copy(&addr, &NET_IPV4_BUF(buf)->src);
+	net_ipaddr_copy(&NET_IPV4_BUF(buf)->src,
+			&NET_IPV4_BUF(buf)->dst);
+	net_ipaddr_copy(&NET_IPV4_BUF(buf)->dst, &addr);
+
+	NET_ICMP_BUF(buf)->type = NET_ICMPV4_ECHO_REPLY;
+	NET_ICMP_BUF(buf)->code = 0;
+	NET_ICMP_BUF(buf)->chksum = 0;
+	NET_ICMP_BUF(buf)->chksum = ~net_calc_chksum_icmpv4(buf);
+
+#if NET_DEBUG > 0
+	snprintf(out, sizeof(out),
+		 net_sprint_ipv4_addr(&NET_IPV4_BUF(buf)->dst));
+	NET_DBG("Sending Echo Reply from %s to %s",
+		net_sprint_ipv4_addr(&NET_IPV4_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_icmpv4_input(struct net_buf *buf, uint16_t len,
+				  uint8_t type, uint8_t code)
+{
+	switch (type) {
+	case NET_ICMPV4_ECHO_REQUEST:
+		return handle_echo_request(buf);
+	}
+
+	return NET_DROP;
+}

net/yaip/icmpv4.h

@@ -0,0 +1,37 @@
+/** @file
+ @brief ICMPv4 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 __ICMPV4_H
+#define __ICMPV4_H
+
+#include <stdint.h>
+
+#include <net/net_ip.h>
+#include <net/nbuf.h>
+
+#define NET_ICMPV4_ECHO_REQUEST 8
+#define NET_ICMPV4_ECHO_REPLY   0
+
+enum net_verdict net_icmpv4_input(struct net_buf *buf, uint16_t len,
+				  uint8_t type, uint8_t code);
+
+#endif /* __ICMPV4_H */

net/yaip/net_core.c

@@ -45,6 +45,10 @@
 #include "icmpv6.h"
 #endif
 
+#if defined(CONFIG_NET_IPV4)
+#include "icmpv4.h"
+#endif
+
 /* Stack for the rx fiber.
  */
 #if !defined(CONFIG_NET_RX_STACK_SIZE)
@@ -205,6 +209,20 @@ drop:
 }
 #endif /* CONFIG_NET_IPV6 */
 
+#if defined(CONFIG_NET_IPV4)
+static inline enum net_verdict process_icmpv4_pkt(struct net_buf *buf,
+						  struct net_ipv4_hdr *ipv4)
+{
+	struct net_icmp_hdr *hdr = NET_ICMP_BUF(buf);
+	uint16_t len = (ipv4->len[0] << 8) + ipv4->len[1];
+
+	NET_DBG("ICMPv4 packet received length %d type %d code %d",
+		len, hdr->type, hdr->code);
+
+	return net_icmpv4_input(buf, len, hdr->type, hdr->code);
+}
+#endif /* CONFIG_NET_IPV4 */
+
 #if defined(CONFIG_NET_IPV4)
 static inline enum net_verdict process_ipv4_pkt(struct net_buf *buf)
 {
@@ -238,6 +256,12 @@ static inline enum net_verdict process_ipv4_pkt(struct net_buf *buf)
 		goto drop;
 	}
 
+	switch (hdr->proto) {
+	case IPPROTO_ICMP:
+		net_nbuf_ip_hdr_len(buf) = sizeof(struct net_ipv4_hdr);
+		return process_icmpv4_pkt(buf, hdr);
+	}
+
 drop:
 	return NET_DROP;
 }

net/yaip/net_private.h

@@ -38,6 +38,11 @@ static inline uint16_t net_calc_chksum_icmpv6(struct net_buf *buf)
 	return net_calc_chksum(buf, IPPROTO_ICMPV6);
 }
 
+static inline uint16_t net_calc_chksum_icmpv4(struct net_buf *buf)
+{
+	return net_calc_chksum(buf, IPPROTO_ICMP);
+}
+
 #if NET_DEBUG > 0
 static inline char *net_sprint_ll_addr(uint8_t *ll, uint8_t ll_len)
 {