1 files changed, 25 insertions, 0 deletions
diff --git a/net/ipv4.h b/net/ipv4.h
new file mode 100644
index 0000000..e3cbc36
--- /dev/null
+++ b/net/ipv4.h
@@ -0,0 +1,25 @@
+// http://www.saminiir.com/lets-code-tcp-ip-stack-2-ipv4-icmpv4/
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "eth.h"
+#include "netdev.h"
+
+struct ipv4_hdr {
+    uint8_t ihl : 4;		 // 4bit / number of 32 bit words in header
+    uint8_t version : 4;	 // 4bit /  4 - ipv4
+    uint8_t tos;		 // type of service
+    uint16_t len;		 // total length of ip datagramm
+    uint16_t id;		 // index of datagram for fragmentation
+    uint16_t flags : 3;		 // various control flags
+    uint16_t frag_offset : 13;	 // fragment offset 0 - first
+    uint8_t ttl;		 // time to live - countdown decreased by each receiver
+    uint8_t proto;		 // payload protocol / 1-icmp, 16 - udp , 6 -tcp
+    uint16_t csum;		 // header checksum
+    uint32_t saddr;		 // source ip address
+    uint32_t daddr;		 // destination ip address
+} __attribute__((packed));
+
+uint16_t ipv4_checksum(void *addr, int count);
+bool ipv4_incoming(struct netdev *,struct eth_hdr *);
+uint16_t ipv4_checksum(void *addr, int count);