archived-lcd4linux/plugin_netdev.c

/* $Id: plugin_netdev.c,v 1.13 2005/01/18 06:30:23 reinelt Exp $
 *
 * plugin for /proc/net/dev parsing
 *
 * Copyright (C) 2003 Michael Reinelt <reinelt@eunet.at>
 * Copyright (C) 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * This file is part of LCD4Linux.
 *
 * LCD4Linux is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * LCD4Linux is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 * $Log: plugin_netdev.c,v $
 * Revision 1.13  2005/01/18 06:30:23  reinelt
 * added (C) to all copyright statements
 *
 * Revision 1.12  2004/06/26 12:05:00  reinelt
 *
 * uh-oh... the last CVS log message messed up things a lot...
 *
 * Revision 1.11  2004/06/26 09:27:21  reinelt
 *
 * added '-W' to CFLAGS
 * changed all C++ comments to C ones
 * cleaned up a lot of signed/unsigned mistakes
 *
 * Revision 1.10  2004/06/17 10:58:58  reinelt
 *
 * changed plugin_netdev to use the new fast hash model
 *
 * Revision 1.9  2004/06/17 06:23:43  reinelt
 *
 * hash handling rewritten to solve performance issues
 *
 * Revision 1.8  2004/05/27 03:39:47  reinelt
 *
 * changed function naming scheme to plugin::function
 *
 * Revision 1.7  2004/03/11 06:39:59  reinelt
 * big patch from Martin:
 * - reuse filehandles
 * - memory leaks fixed
 * - earlier busy-flag checking with HD44780
 * - reuse memory for strings in RESULT and hash
 * - netdev_fast to wavid time-consuming regex
 *
 * Revision 1.6  2004/03/03 04:44:16  reinelt
 * changes (cosmetics?) to the big patch from Martin
 * hash patch un-applied
 *
 * Revision 1.5  2004/03/03 03:47:04  reinelt
 * big patch from Martin Hejl:
 * - use qprintf() where appropriate
 * - save CPU cycles on gettimeofday()
 * - add quit() functions to free allocated memory
 * - fixed lots of memory leaks
 *
 * Revision 1.4  2004/02/15 07:23:04  reinelt
 * bug in netdev parsing fixed
 *
 * Revision 1.3  2004/02/01 19:37:40  reinelt
 * got rid of every strtok() incarnation.
 *
 * Revision 1.2  2004/01/29 04:40:02  reinelt
 * every .c file includes "config.h" now
 *
 * Revision 1.1  2004/01/25 05:30:09  reinelt
 * plugin_netdev for parsing /proc/net/dev added
 *
 */

/* 
 * exported functions:
 *
 * int plugin_init_netdev (void)
 *  adds functions to access /proc/net/dev
 *
 */


#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "debug.h"
#include "plugin.h"
#include "qprintf.h"
#include "hash.h"


static HASH NetDev;
static FILE *Stream = NULL;
static char *DELIMITER = " :|\t\n";

static int parse_netdev (void)
{
  int age;
  int row, col;
  static int first_time = 1;
  
  /* reread every 10 msec only */
  age = hash_age(&NetDev, NULL);
  if (age > 0 && age <= 10) return 0;
  
  if (Stream == NULL) Stream = fopen("/proc/net/dev", "r");
  if (Stream == NULL) {
    error ("fopen(/proc/net/dev) failed: %s", strerror(errno));
    return -1;
  }

  rewind(Stream);    
  row = 0;
  
  while (!feof(Stream)) {
    char buffer[256];
    char dev[16];
    char *beg, *end;
    unsigned int len;
    
    if (fgets (buffer, sizeof(buffer), Stream) == NULL) break;
    
    switch (++row) {
      
    case 1:
      /* skip row 1 */
      continue;
      
    case 2:
      /* row 2 used for headers */
      if (first_time) {
	char *RxTx = strrchr(buffer, '|');
	first_time = 0;
	col = 0;
	beg = buffer;
	while (beg) {
	  char key[32];
	  
	  while (strchr(DELIMITER, *beg)) beg++;
	  if ((end = strpbrk(beg, DELIMITER)) != NULL) *end = '\0';
	  qprintf(key, sizeof(key), "%s_%s", beg < RxTx ? "Rx" : "Tx", beg);
	  hash_set_column (&NetDev, col++, key);
	  beg = end ? end + 1 : NULL;
	}
      }
      continue;

    default:
      /* fetch interface name (1st column) as key */
      beg = buffer;
      while (*beg && *beg == ' ') beg++;
      end = beg + 1;
      while (*end && *end != ':') end++;
      len = end - beg;
      if (len >= sizeof(dev)) len = sizeof(dev)-1;
      strncpy (dev, beg, len);
      dev[len] = '\0';
      
      hash_put_delta (&NetDev, dev, buffer); 
    }
  }
  
  return 0;
}  

static void my_netdev (RESULT *result, RESULT *arg1, RESULT *arg2, RESULT *arg3)
{
  char *dev, *key;
  int delay;
  double value;
  
  if (parse_netdev()<0) {
    SetResult(&result, R_STRING, ""); 
    return;
  }

  dev   = R2S(arg1);
  key   = R2S(arg2);
  delay = R2N(arg3);
  
  value  = hash_get_regex(&NetDev, dev, key, delay);
  
  SetResult(&result, R_NUMBER, &value); 
}

static void my_netdev_fast(RESULT *result, RESULT *arg1, RESULT *arg2, RESULT *arg3)
{
  char *dev, *key;
  int delay;
  double value;
  
  if (parse_netdev()<0) {
    SetResult(&result, R_STRING, ""); 
    return;
  }

  dev   = R2S(arg1);
  key   = R2S(arg2);
  delay = R2N(arg3);
  
  value  = hash_get_delta(&NetDev, dev, key, delay);
  
  SetResult(&result, R_NUMBER, &value); 
}


int plugin_init_netdev (void)
{
  hash_create(&NetDev);
  hash_set_delimiter (&NetDev, " :|\t\n");

  AddFunction ("netdev",       3, my_netdev);
  AddFunction ("netdev::fast", 3, my_netdev_fast);
  return 0;
}

void plugin_exit_netdev(void) 
{
  if(Stream!=NULL) {
    fclose (Stream);
    Stream=NULL;
  }
  hash_destroy(&NetDev);
}