first commit

src/ip.h

@@ -0,0 +1,67 @@
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <endian.h>
+#include "defs.h"
+#include "icmp.h"
+
+#define IP_PLUGGED_PROTOCOLS_MAX 4
+
+typedef struct {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+    uint8_t  header_length: 4;
+    uint8_t  version: 4;
+#endif
+#if __BYTE_ORDER == __BIG_ENDIAN
+    uint8_t  version: 4;
+    uint8_t  header_length: 4;
+#endif
+    uint8_t  type_of_service;
+    uint16_t total_length;
+    uint16_t id;
+    uint16_t fragment_offset;
+    uint8_t  time_to_live;
+    uint8_t  protocol;
+    uint16_t checksum;
+    uint32_t src_ip;
+    uint32_t dst_ip;
+    char     payload[];
+} ip_packet_t;
+static_assert(sizeof(ip_packet_t) == 20);
+
+typedef enum {
+    IP_PROTOCOL_ICMP = 1,
+    IP_PROTOCOL_TCP  = 6,
+    IP_PROTOCOL_UDP  = 17,
+} ip_protocol_t;
+
+typedef struct {
+    uint8_t protocol;
+    void *data;
+    void (*process_packet)(void*, ip_address_t, const void*, size_t);
+} ip_plugged_protocol_t;
+
+typedef struct {
+    ip_address_t ip;
+    
+    uint32_t next_id;
+
+    void  *output_ptr;
+    size_t output_max;
+
+    icmp_state_t icmp_state;
+
+    void *send_data;
+    void (*send)(void*, ip_address_t, size_t);
+
+    size_t plugged_protocols_count;
+    ip_plugged_protocol_t plugged_protocols[IP_PLUGGED_PROTOCOLS_MAX];
+} ip_state_t;
+
+void ip_seconds_passed(ip_state_t *state, size_t seconds);
+void ip_change_output_buffer(ip_state_t *state, void *ptr, size_t max);
+void ip_init(ip_state_t *state, ip_address_t ip, void *send_data, void (*send)(void*, ip_address_t, size_t));
+void ip_free(ip_state_t *state);
+int  ip_send(ip_state_t *state, ip_protocol_t protocol, ip_address_t dst, bool no_fragm, const void *src, size_t len);
+void ip_process_packet(ip_state_t *state, const void *packet, size_t len);
+bool ip_plug_protocol(ip_state_t *ip_state, uint8_t protocol, void *data, void (*process_packet)(void *data, ip_address_t sender, const void *packet, size_t len));