Add ARP tables and reply function

include/net/arp.h

@@ -4,6 +4,9 @@
 #define ARP_H_ETH           1
 #define ARP_P_IP            0x0800
 
+#define ARP_OP_REQUEST      1
+#define ARP_OP_REPLY        2
+
 struct arp_frame {
     uint16_t htype;
     uint16_t ptype;

include/net/eth.h

@@ -11,5 +11,8 @@ struct eth_frame {
     uint16_t ethertype;
 } __attribute__((packed));
 
+struct netdev;
 struct packet;
 void eth_handle_frame(struct packet *p);
+
+int eth_send_wrapped(struct netdev *src, const uint8_t *dst, uint16_t et, void *data, size_t len);

include/net/if.h

@@ -6,6 +6,7 @@
 #define IF_T_ETH        1
 
 struct netdev;
+struct arp_ent;
 
 typedef int (*netdev_send_func_t) (struct netdev *, const void *, size_t);
 
@@ -17,7 +18,8 @@ struct netdev {
     uint32_t flags;
     int type;
 
-    // TODO: arp table here?
+    // ARP entry list
+    struct arp_ent *arp_ent_head;
 
     netdev_send_func_t send;
 

include/net/util.h

@@ -9,6 +9,14 @@
 
 void strmac(char *dst, const uint8_t *hw);
 
+static inline uint32_t ntohl(uint32_t w) {
+    uint8_t *s = (uint8_t *)&w;
+    return (uint32_t) (s[0] << 24 | s[1] << 16 | s[2] << 8 | s[3]);
+}
+
 static inline uint16_t ntohs(uint16_t w) {
     return (w >> 8) | (w << 8);
 }
+static inline uint16_t htons(uint16_t w) {
+    return (w >> 8) | (w << 8);
+}