added useful log messages

src/arp.c

@@ -695,6 +695,16 @@ arp_process_result_t arp_process_packet(arp_state_t *state, const void *packet,
         return ARP_PROCESS_RESULT_INVALID;
     }
 
+    ARP_DEBUG_LOG("ARP from %d.%d.%d.%d to %d.%d.%d.%d",
+        ((uint8_t*) &packet2->sender_protocol_address)[0],
+        ((uint8_t*) &packet2->sender_protocol_address)[1],
+        ((uint8_t*) &packet2->sender_protocol_address)[2],
+        ((uint8_t*) &packet2->sender_protocol_address)[3],
+        ((uint8_t*) &packet2->target_protocol_address)[0],
+        ((uint8_t*) &packet2->target_protocol_address)[1],
+        ((uint8_t*) &packet2->target_protocol_address)[2],
+        ((uint8_t*) &packet2->target_protocol_address)[3]);
+
     bool merge = arp_translation_table_update(&state->table, packet2->sender_hardware_address, 
                                               packet2->sender_protocol_address, state->cache_timeout);
 

src/ip.c

@@ -223,6 +223,16 @@ void ip_process_packet(ip_state_t *ip_state, const void *packet, size_t len)
         return;
     }
 
+    IP_DEBUG_LOG("Received packet for %d.%d.%d.%d (I'm %d.%d.%d.%d)", 
+        ((uint8_t*) &packet2->dst_ip)[0],
+        ((uint8_t*) &packet2->dst_ip)[1],
+        ((uint8_t*) &packet2->dst_ip)[2],
+        ((uint8_t*) &packet2->dst_ip)[3],
+        ((uint8_t*) &ip_state->ip)[0],
+        ((uint8_t*) &ip_state->ip)[1],
+        ((uint8_t*) &ip_state->ip)[2],
+        ((uint8_t*) &ip_state->ip)[3]);
+
     if (packet2->dst_ip != ip_state->ip) {
         IP_DEBUG_LOG("Packet not for me");
         return;

src/tcp.c

@@ -41,10 +41,6 @@ void tcp_seconds_passed(tcp_state_t *state, size_t seconds)
     (void) seconds;
 }
 
-typedef enum {
-    TCP_CONNECTION_
-} tcp_connection_state;
-
 static tcp_connection_t*
 connection_create_waiting_for_ack(tcp_listener_t *listener, 
                               uint32_t seq_no, uint32_t ack_no,

src/tcp.h

@@ -53,6 +53,19 @@ struct tcp_listener_t {
     void  *callback_data;
 };
 
+typedef enum {
+    TCP_STATE_CLOSED,
+    TCP_STATE_LISTEN,
+    TCP_STATE_SYN_SENT,
+    TCP_STATE_SYN_RCVD,
+    TCP_STATE_ESTAB,
+    TCP_STATE_FIN_WAIT_1,
+    TCP_STATE_FIN_WAIT_2,
+    TCP_STATE_CLOSE_WAIT,
+    TCP_STATE_LAST_ACK,
+    TCP_STATE_TIME_WAIT,
+} tcp_state_t;
+
 struct tcp_connection_t {
     tcp_listener_t   *listener; // Listener that accepted this connection
     tcp_connection_t *next;