/*
 * ktcpdump.c
 * libpcap を使った TCP パケット解析サンプルコード
 * Ctrl-C で終了。
 */

#define PROG_NAME "ktcpdump"

#include "mystab_pcap.h"
#include "apr_getopt.h"

static const apr_getopt_option_t opt_option[] = {
  /* long-option, short-option, has-arg flag, description */
  { "port_number", 'p', TRUE, "[MUST] port_number" },
  { "interface", 'i', TRUE, "[MUST] network device to use" },
  { "help", 'h', FALSE, "[OPTION] show help" },    /* -h or --help */

#if defined(WIN32) || defined(WINDOWS) || defined(MSVC)

  { "disp_interfaces", 'D', FALSE,
    "[OPTION] displays avalable interfaces (Windows Only)" },

#endif


  { NULL, 0, 0, NULL }, /* SENTINEL */
};

void print_usage (apr_file_t *out) {
  apr_getopt_option_t *ptr = (apr_getopt_option_t *)opt_option;
  
  apr_file_printf(out, "Usage: %s ", PROG_NAME);
  while (ptr && ptr->name) {
    if (ptr->has_arg) {
      apr_file_printf(out, "[ -%c <arg> | --%s <arg> ] ", ptr->optch,
       ptr->name);
    } else {
      apr_file_printf(out, "[ -%c | --%s ] ", ptr->optch, ptr->name);
    }
    ptr++;
  }
  apr_file_printf(out, "\n");
  ptr = (apr_getopt_option_t *)opt_option;
  while (ptr && ptr->name) {
    apr_file_printf(out, "\t-%c, --%s\t: %s\n", ptr->optch, ptr->name,
      ptr->description);
    ptr++;
  }
  
}

int my_pcap_init (
  int ac
  , char **av
  , my_pcap_params *params
  , apr_file_t *astderr
  , apr_pool_t *pool
) {
  apr_status_t rv = APR_SUCCESS;

  apr_getopt_t *opt = NULL;
  int opt_ch = 0;
  const char *opt_arg = NULL;

  apr_uint16_t port_number = 0;
  const char * interface_str = NULL;

  if (ac < 2) {
    print_usage(astderr);
    return 0;
  }
  
  rv = apr_getopt_init(&opt, pool, ac, (const char * const *)av);
  
  if (rv != APR_SUCCESS) {
    apr_file_printf(astderr, "ERROR: apr_getopt_init\n");
    return 0;
  }
  
  while ((rv = apr_getopt_long(opt, opt_option, &opt_ch, &opt_arg))
    == APR_SUCCESS) {

    switch (opt_ch) {
      case 'p':
        port_number = atoi(opt_arg);
      break;
      case 'i':
        interface_str = opt_arg;
      break;

#if defined(WIN32) || defined(WINDOWS) || defined(MSVC)

      case 'D':
        {
          char errbuf[80];
          if (! disp_devices(astderr, errbuf, sizeof(errbuf))) {
            apr_file_printf(astderr, "ERROR: disp_devices: %s\n", errbuf);
          }
        }
        return 0;
      break;

#endif

      case 'h':
        print_usage(astderr);
        return 0;
    }

  }
  
  if (rv != APR_EOF || port_number<=0 || !interface_str) {
    print_usage(astderr);
    return 0;
  }
  
  params->device = interface_str;
  params->filter = apr_psprintf(pool, "tcp port %d", port_number);
  
  return 1;
}

void my_pcap_main(
  apr_pool_t *pool
  , apr_file_t *out
  , my_tcp_pkt *d
) {
  if (!d || !pool || !out) {
    return;
  }
  
  apr_file_printf(out, "[%s:%d-%s:%d] seq_no=%d ack_no=%d size=%d\n",
    d->ip_src_addr, d->tcp_src_port, d->ip_dst_addr, d->tcp_dst_port,
    d->tcp_seq_no, d->tcp_ack_no,
    d->tcp_payload_size);
  apr_file_printf(out, "\turg=%d ack=%d psh=%d rst=%d syn=%d fin=%d",
    d->tcp_urg_bit, d->tcp_ack_bit, d->tcp_psh_bit, d->tcp_rst_bit,
    d->tcp_syn_bit, d->tcp_fin_bit);

  if (d->tcp_payload_size > 0) {
    int i=0;
    for (i=0; i<d->tcp_payload_size; i++) {
      if (i%32 == 0) {
        apr_file_printf(out, "\n");
      }
      apr_file_printf(out, "%02X", d->tcp_payload_pos[i]);
    }
    apr_file_printf(out, "\n");
  }

  apr_file_printf(out, "\n");
}

void my_pcap_finally (
  apr_file_t *out
) {
  apr_file_printf(out, "done.\n");
}