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/**
 * @file datatop_ip_table_poll.c
 * @brief Adds ability for TP Tables, Rules and Routes data collection
          Unlike other polls, this is intended for running as a separate
          thread as it can cause delays of > 3sec per poll
 *
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <pthread.h>
#include "datatop_interface.h"
#include "datatop_fileops.h"
#include "datatop_str.h"
#include "datatop_polling.h"

#define DTOP_IPTRR_POLL_PERIOD  5.00

/**
* @struct dtop_ip_table_vars
* @brief Struct used to hold necessary variables for /proc/stat dpg
*
* @var dtop_ip_table_vars::line
* Array of strings where necessary dp names and values are held.
* @var dtop_ip_table_vars::line_count
* Number of lines the file is that the dpg represents.
*/
struct dtop_ip_table_vars {
	char *out_dir;
}dtop_ip_table_storage;

struct dtop_linked_list *ip_dpg_list = NULL;

pthread_mutex_t dtop_ip_table_lock;

/**
 * @brief Perform IP table command and store it in a file
 *
 * @param dpg Struct that polled data is added to.
 * @return DTOP_POLL_IO_ERR - Poll of dpg unsuccessful.
 * @return DTOP_POLL_OK - Poll of dpg successful.
 */
int dtop_ip_table_poll(struct dtop_data_point_gatherer *dpg)
{
  FILE *fd;
  FILE *fo = (FILE *)dpg->file;
  char buf[1001];

  time_t rawtime;
  struct tm * timeinfo;

  if(fo == NULL)
  {
    fprintf(stderr, "Could not fopen: %s\n", dpg->file);
	  return DTOP_POLL_IO_ERR;
  }

  time ( &rawtime );
  timeinfo = gmtime ( &rawtime );

  fprintf ( fo, "============\nStart: %s==========\n", asctime (timeinfo) );
  fflush(fo);

  /* redirect stderr to output file */
  dup2(fileno(fo), 2);

  fd = popen((char *)dpg->priv, "r");
  if(fd == NULL)
  {
    fprintf(stderr, "Could not popen: %s\n", (char *)dpg->priv);
	  return DTOP_POLL_IO_ERR;
  }

  while(fgets(buf, 1000, fd) != NULL)
  {
    fputs(buf, fo);
  }

  fprintf ( fo, "============\nEnd: %s==========\n\n", asctime (timeinfo) );
  fflush(fo);
  pclose(fd);
	return DTOP_POLL_OK;
}

/**
 * @brief Frees dynamically allocated IP table dpg.
 *
 * Frees the memory of the dpg along with it's data_points
 * and other malloc'd memory no longer needed.
 *
 * @param dpg Dpg to deconstruct and deallocate memory for.
 */
static void dtop_ip_table_dpg_deconstructor
			(struct dtop_data_point_gatherer *dpset)
{
	free(dpset->prefix);
  if(dpset->file)
  {
     fclose((FILE *)dpset->file);
  }

	free(dpset);
}

/**
 * @brief Registers a new IP table dpg to the list.
 *
 * @param dpg Dpg to construct and allocate memory for.
 */
void dtop_ip_table_register(struct dtop_data_point_gatherer *dpg)
{
  if (dpg)
    ip_dpg_list = dtop_add_linked_list(dpg, ip_dpg_list);
}

/**
 * @brief Open the files for writing the output for each dpg.
 *
 * @param None
 */
int dtop_ip_table_init_files()
{
  struct dtop_data_point_gatherer *dpset;
  struct dtop_linked_list *curr_ptr = ip_dpg_list;
  FILE *fd;

  while(curr_ptr)
  {
    dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
    fd = fopen(dpset->prefix, "a+");
    if(!fd)
    {
      fprintf(stderr, "Could not fopen: %s\n", dpset->prefix);
      return DTOP_POLL_IO_ERR;
    }
    dpset->file = (char *)fd;
    curr_ptr = curr_ptr->next_ptr;
  }
  return DTOP_POLL_OK;
}

/**
 * @brief Perform cleanup of IP table dgp list at exit.
 *
 * @param None
 */
void dtop_ip_table_poll_cleanup()
{
  pthread_mutex_lock(&dtop_ip_table_lock);
  deconstruct_dpgs(ip_dpg_list);
  dtop_rem_linked_list(ip_dpg_list);
  pthread_mutex_unlock(&dtop_ip_table_lock);

}

/**
 * @brief The thread to poll for IP table data.
 *
 * @param arg ptr
 */
void *dtop_ip_table_start_poll(void *arg)
{
  time_t start_t, curr_t;
  double diff_t = 9999999.00; /* some high # > DTOP_IPTRR_POLL_PERIOD */
  int ret = DTOP_POLL_OK;

  (void) arg;

  if (pthread_mutex_init(&dtop_ip_table_lock, NULL) != 0)
  {
      printf("\n mutex init failed\n");
      return NULL;
  }

  atexit(dtop_ip_table_poll_cleanup);

  if(DTOP_POLL_OK != ( ret = dtop_ip_table_init_files()))
  {
    return NULL;
  }

  while(1)
  {
    struct dtop_linked_list *curr_ptr = ip_dpg_list;
    struct dtop_data_point_gatherer *dpset;

    pthread_mutex_lock(&dtop_ip_table_lock);

    if (diff_t >= DTOP_IPTRR_POLL_PERIOD)
    {
      printf("Poll for IP Tables, Rules & Routes\n");
      time(&start_t);
      while (curr_ptr)
      {
        dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
        dpset->poll(dpset);
        curr_ptr = curr_ptr->next_ptr;
      }
    }
    pthread_mutex_unlock(&dtop_ip_table_lock);

    /* sleep for 500 milliseconds */
    usleep(500 * 1000);
    time(&curr_t);
    diff_t = difftime(curr_t, start_t);
  }
  return NULL;
}

/**
 * @brief Creates a dpg for ip table command
 *
 * Dynamically allocates memory for dpg which is then added to a linked list
 * via the dtop_register(dpg) function call.
 *
 * @param data_points dtop_data_point struct that dpg points to.
 * @param storage dtop_ip_table_vars struct that holds relevant dpg variables.
 */
/*static void construct_ip_table_dpg(struct dtop_data_point
		*data_points, struct dtop_ip_table_vars *command, int dp_count)
*/
static void construct_ip_table_dpg(char *command)
{
	struct dtop_data_point_gatherer *dpg = malloc
		(sizeof(struct dtop_data_point_gatherer));
  char *file_name = (char *)malloc(strlen(command)+ 1 + 1 + strlen(dtop_ip_table_storage.out_dir) + 4);
  int i, fname_start_ind;

  strcpy(file_name, dtop_ip_table_storage.out_dir);
  strcat(file_name, "/");

  fname_start_ind = strlen(file_name);
  strcat(file_name, command);
  strcat(file_name, ".txt");

  for(i=fname_start_ind; file_name[i]; i++)
  {
    if(file_name[i] == ' ')
      file_name[i] = '_';
    if(file_name[i] == '/')
      file_name[i] = '-';
  }

	dpg->prefix = file_name;
	dpg->poll = dtop_ip_table_poll;
	dpg->priv = (char *)command;
  dpg->file = NULL;
	dpg->deconstruct = dtop_ip_table_dpg_deconstructor;

	dtop_ip_table_register(dpg);
}

/*
 * @brief Scans "/proc/stat" in order to autodetect dps.
 *
 * Searches through "/proc/stat" file for all available data
 * points to create as dp structs.
 *
 * @param storage dtop_ip_table_vars struct where relevant variables are stored.
 */

/**
 * @brief Calls dtop_search for "/proc/stat" file.
 */
void dtop_ip_table_init(char *out_dir)
{
	dtop_ip_table_storage.out_dir = out_dir;
  construct_ip_table_dpg("ip xfrm state show");
  construct_ip_table_dpg("ip xfrm policy show");
  construct_ip_table_dpg("ip addr");
  construct_ip_table_dpg("iptables -t raw -L -n -v");
  construct_ip_table_dpg("iptables -t mangle -L -n -v");
  construct_ip_table_dpg("iptables -L -n -v");
  construct_ip_table_dpg("iptables -t nat -L -n -v");
  construct_ip_table_dpg("ip6tables -t raw -L -n -v");
  construct_ip_table_dpg("ip6tables -t mangle -L -n -v");
  construct_ip_table_dpg("ip6tables -L -n -v");
  construct_ip_table_dpg("ip6tables -t nat -L -n -v");
  construct_ip_table_dpg("ip rule show");
  construct_ip_table_dpg("ip -6 rule show");
  construct_ip_table_dpg("ip route show table all");
  construct_ip_table_dpg("ip -6 route show table all");
  construct_ip_table_dpg("ip route show table rmnet_data0");
  construct_ip_table_dpg("ip route show table rmnet_data1");
  construct_ip_table_dpg("ip route show table rmnet_data2");
  construct_ip_table_dpg("ip route show table rmnet_data6");
  construct_ip_table_dpg("ip route show table rmnet_data7");
  construct_ip_table_dpg("ip route show table r_rmnet_data0");
  construct_ip_table_dpg("ip route show table r_rmnet_data1");
  construct_ip_table_dpg("ip route show table r_rmnet_data2");
  construct_ip_table_dpg("ip route show table r_rmnet_data6");
  construct_ip_table_dpg("ip route show table r_rmnet_data7");
  construct_ip_table_dpg("ip -6 route show table rmnet_data0");
  construct_ip_table_dpg("ip -6 route show table rmnet_data1");
  construct_ip_table_dpg("ip -6 route show table rmnet_data2");
  construct_ip_table_dpg("ip -6 route show table rmnet_data6");
  construct_ip_table_dpg("ip -6 route show table rmnet_data7");
  construct_ip_table_dpg("ip -6 route show table r_rmnet_data0");
  construct_ip_table_dpg("ip -6 route show table r_rmnet_data1");
  construct_ip_table_dpg("ip -6 route show table r_rmnet_data2");
  construct_ip_table_dpg("ip -6 route show table r_rmnet_data6");
  construct_ip_table_dpg("ip -6 route show table r_rmnet_data7");
  construct_ip_table_dpg("ip route show table wlan0");
  construct_ip_table_dpg("ip -6 route show table wlan0");
  construct_ip_table_dpg("ip route show table dummy0");
  construct_ip_table_dpg("ip -6 route show table dummy0");
  construct_ip_table_dpg("cat /proc/net/xfrm_stat");
  construct_ip_table_dpg("cat /proc/sys/net/ipv4/ip_forward");
  construct_ip_table_dpg("cat /proc/sys/net/ipv6/conf/all/forwarding");

  printf("Poll for IP Tables, Rules & Routes every 5 seconds\n");
}