utun2/!/packet_dump.h

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <arpa/inet.h>
#include <netinet/in.h>

// Packet dump function for debugging
static void dump_packet(const char* direction, const uint8_t* data, size_t len, struct sockaddr_storage* addr) {
    printf("[DUMP] %s packet: %zd bytes ", direction, len);
    
    // Print address if provided
    if (addr) {
        if (addr->ss_family == AF_INET) {
            struct sockaddr_in* sin = (struct sockaddr_in*)addr;
            printf("to/from %s:%d ", 
                   inet_ntoa(sin->sin_addr), 
                   ntohs(sin->sin_port));
        }
    }
    
    // Print first 64 bytes
    printf("data: ");
    for (size_t i = 0; i < len && i < 64; i++) {
        printf("%02x", data[i]);
        if (i % 4 == 3) printf(" ");
    }
    if (len > 64) printf("...");
    
    // If it's INIT packet, parse fields
    if (len > 0 && data[0] == 0x02) { // ETCP_INIT_REQUEST
        if (len >= 15) { // Minimum INIT size: code(1) + node_id(8) + mtu(2) + keepalive(2) + pubkey(2 at least)
            uint64_t node_id = 0;
            memcpy(&node_id, data + 1, 8);
            uint16_t mtu = (data[9] << 8) | data[10];
            uint16_t keepalive = (data[11] << 8) | data[12];
            printf(" | INIT: node_id=%llu mtu=%d keepalive=%d", 
                   (unsigned long long)node_id, mtu, keepalive);
        }
    }
    
    printf("\n");
}