esp-firewall/ESPTest/src/lwip_hooks.c

#include "lwip_hooks.h"

const char *get_protocol(u16_t type)
{
    switch (type)
    {
    case 1:
        return "ICMP";
    case 6:
        return "TCP";
    case 17:
        return "UDP";
    default:
        return "-";
    }
}

int lwip_hook_ip4_input(struct pbuf *pbuf, struct netif *input_netif)
{
    const struct ip_hdr *iphdr;
    char ip_address[IP_HLEN];

    iphdr = (struct ip_hdr *)pbuf->payload;
    sprintf(ip_address, "%d.%d.%d.%d", ip4_addr1_16_val(iphdr->src), ip4_addr2_16_val(iphdr->src), ip4_addr3_16_val(iphdr->src), ip4_addr4_16_val(iphdr->src));
    ESP_LOGI("HOOK", "%s: %s",
             get_protocol((u16_t)IPH_PROTO(iphdr)), ip_address);
    return ESP_OK;
}