net: Receive IPv4 packet

Check if we have received IPv4 packet and call a handler
function to process it.

Change-Id: I9f9e5f0888d2c3b91401c98f4925647ddce09962
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

drivers/slip/slip.c

@@ -192,11 +192,6 @@ static void process_msg(struct slip_context *slip)
 		return;
 	}
 
-#if defined(CONFIG_NET_IPV4)
-#error "FIXME - TBDL"
-#endif /* IPv4 */
-
-#if defined(CONFIG_NET_IPV6)
 	if (buf->frags) {
 		if (net_recv(net_if_get_by_link_addr(&slip->ll_addr),
 			     buf) < 0) {
@@ -204,7 +199,6 @@ static void process_msg(struct slip_context *slip)
 		}
 		slip->rx = slip->last = NULL;
 	}
-#endif /* CONFIG_NET_IPV6 */
 }
 
 static inline int slip_input_byte(struct slip_context *slip,

include/net/yaip/net_ip.h

@@ -168,6 +168,19 @@ struct net_ipv6_hdr {
 	struct in6_addr dst;
 } __attribute__((__packed__));
 
+struct net_ipv4_hdr {
+	uint8_t vhl;
+	uint8_t tos;
+	uint8_t len[2];
+	uint8_t id[2];
+	uint8_t offset[2];
+	uint8_t ttl;
+	uint8_t proto;
+	uint16_t chksum;
+	struct in_addr src;
+	struct in_addr dst;
+} __attribute__((__packed__));
+
 #define NET_UDPH_LEN	8			/* Size of UDP header */
 #define NET_TCPH_LEN	20			/* Size of TCP header */
 #define NET_ICMPH_LEN	4			/* Size of ICMP header */

net/yaip/net_core.c

@@ -162,6 +162,44 @@ drop:
 }
 #endif /* CONFIG_NET_IPV6 */
 
+#if defined(CONFIG_NET_IPV4)
+static inline enum net_verdict process_ipv4_pkt(struct net_buf *buf)
+{
+	struct net_ipv4_hdr *hdr = NET_IPV4_BUF(buf);
+	int real_len = net_buf_frags_len(buf);
+	int pkt_len = (hdr->len[0] << 8) + hdr->len[1];
+
+	if (real_len > pkt_len) {
+		NET_DBG("IPv4 adjust pkt len to %d (was %d)",
+			pkt_len, real_len);
+		net_buf_frag_last(buf)->len -= real_len - pkt_len;
+		real_len -= pkt_len;
+	} else if (real_len < pkt_len) {
+		NET_DBG("IPv4 packet size %d buf len %d", pkt_len, real_len);
+		NET_STATS(++net_stats.ipv4.drop);
+		return NET_DROP;
+	}
+
+#if NET_DEBUG > 0
+	do {
+		char out[sizeof("xxx.xxx.xxx.xxx")];
+		snprintf(out, sizeof(out), net_sprint_ipv4_addr(&hdr->dst));
+		NET_DBG("IPv4 packet received from %s to %s",
+			net_sprint_ipv4_addr(&hdr->src), out);
+	} while (0);
+#endif /* NET_DEBUG > 0 */
+
+	if (!net_is_my_ipv4_addr(&hdr->dst)) {
+		NET_DBG("IPv4 packet in buf %p not for me", buf);
+		NET_STATS(++net_stats.ipv4.drop);
+		goto drop;
+	}
+
+drop:
+	return NET_DROP;
+}
+#endif /* CONFIG_NET_IPV4 */
+
 static inline enum net_verdict process_data(struct net_buf *buf)
 {
 	/* If there is no data, then drop the packet. Also if
@@ -182,10 +220,15 @@ static inline enum net_verdict process_data(struct net_buf *buf)
 		NET_STATS(++net_stats.ipv6.recv);
 		net_nbuf_family(buf) = PF_INET6;
 		return process_ipv6_pkt(buf);
+#endif
+#if defined(CONFIG_NET_IPV4)
+	case 0x40:
+		NET_STATS(++net_stats.ipv4.recv);
+		net_nbuf_family(buf) = PF_INET;
+		return process_ipv4_pkt(buf);
 #endif
 	}
 
-drop:
 	NET_STATS(++net_stats.ip_errors.protoerr);
 	NET_STATS(++net_stats.ip_errors.vhlerr);
 	return NET_DROP;

samples/net/echo_server/src/echo-server-yaip.c

@@ -42,29 +42,30 @@
 
 #if defined(CONFIG_NET_IPV6)
 /* admin-local, dynamically allocated multicast address */
-#define MCAST_IPADDR { { { 0xff, 0x84, 0, 0, 0, 0, 0, 0, \
+#define MCAST_IP6ADDR { { { 0xff, 0x84, 0, 0, 0, 0, 0, 0, \
-			   0, 0, 0, 0, 0, 0, 0, 0x2 } } }
+			    0, 0, 0, 0, 0, 0, 0, 0x2 } } }
 
 /* Define my IP address where to expect messages */
 #if !defined(CONFIG_NET_TESTING)
-#define MY_IPADDR { { { 0x20, 0x01, 0x0d, 0xb8, 0, 0, 0, 0, \
+#define MY_IP6ADDR { { { 0x20, 0x01, 0x0d, 0xb8, 0, 0, 0, 0, \
-			0, 0, 0, 0, 0, 0, 0, 0x1 } } }
+			 0, 0, 0, 0, 0, 0, 0, 0x1 } } }
 #define MY_PREFIX_LEN 64
 #endif
 
 #if defined(CONFIG_NET_TESTING)
 static const struct in6_addr in6addr_my = IN6ADDR_ANY_INIT;
 #else
-static const struct in6_addr in6addr_my = MY_IPADDR;
+static const struct in6_addr in6addr_my = MY_IP6ADDR;
 #endif
 
-#else /* IPv6 */
-
-/* Organization-local 239.192.0.0/14 */
-#define MCAST_IPADDR { { { 239, 192, 0, 2 } } }
-
 #endif /* IPv6 */
 
+#if defined(CONFIG_NET_IPV4)
+/* Organization-local 239.192.0.0/14 */
+#define MCAST_IP4ADDR { { { 239, 192, 0, 2 } } }
+#define MY_IP4ADDR { { { 192, 168, 0, 1 } } }
+#endif /* IPv4 */
+
 #define MY_PORT 4242
 
 static inline void init_app(void)
@@ -97,7 +98,7 @@ static inline bool get_context(struct net_context **udp_recv4,
 	static struct net_addr any_addr6;
 	static struct net_addr my_addr6;
 	static const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
-	static const struct in6_addr in6addr_mcast = MCAST_IPADDR;
+	static const struct in6_addr in6addr_mcast = MCAST_IP6ADDR;
 #endif
 
 #if defined(CONFIG_NET_IPV4)
@@ -105,8 +106,8 @@ static inline bool get_context(struct net_context **udp_recv4,
 	static struct net_addr any_addr4;
 	static struct net_addr my_addr4;
 	static const struct in_addr in4addr_any = { { { 0 } } };
-	static struct in_addr in4addr_my = MY_IPADDR;
+	static struct in_addr in4addr_my = MY_IP4ADDR;
-	static struct in_addr in4addr_mcast = MCAST_IPADDR;
+	static struct in_addr in4addr_mcast = MCAST_IP4ADDR;
 #endif
 
 #if defined(CONFIG_NET_IPV6)