net/icmp.h


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//http://www.saminiir.com/lets-code-tcp-ip-stack-2-ipv4-icmpv4/
#include <stdint.h>
#include <stdbool.h>

#include "netdev.h"

struct icmp_v4 {
    uint8_t type;	    // purpose 0-echo reply, 3- unreachable, 8- echo request, etc...
    uint8_t code;	    // reason (type=3,code=0 net unreachable, etc..)
    uint16_t csum;	    // checksum (Same as in ipv4 header)
    uint8_t data[];	    // payload (example icmp_v4_echo)
} __attribute__((packed));

// payload
struct icmp_v4_echo {
    uint16_t id;	    // set by sender
    uint16_t seq;	    // starting at 0
    uint8_t data[];	    // optinal (example timestamp)
} __attribute__((packed));

struct icmp_v4_dst_unreachable {
    uint8_t unused;	    
    uint8_t len;	    // lenght of original datagramm
    uint16_t var;	    // depends on icmp code
    uint8_t data[];
} __attribute__((packed));

bool icmp_incoming(struct netdev *dev,struct icmp_v4 *data, uint32_t count_bytes);