/*

   * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)

   * Licensed under the GPL.
   */

  #include <errno.h>
  #include <pcap.h>

  #include <string.h>

  #include <asm/types.h>
  #include "net_user.h"
  #include "pcap_user.h"

  #include "um_malloc.h"

  #define PCAP_FD(p) (*(int *)(p))

  static int pcap_user_init(void *data, void *dev)

  {
  	struct pcap_data *pri = data;
  	pcap_t *p;
  	char errors[PCAP_ERRBUF_SIZE];

  	p = pcap_open_live(pri->host_if, ETH_MAX_PACKET + ETH_HEADER_OTHER,
  			   pri->promisc, 0, errors);

  	if (p == NULL) {

  		printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - "
  		       "'%s'
  ", errors);

  		return -EINVAL;

  	}
  
  	pri->dev = dev;
  	pri->pcap = p;

  	return 0;

  }
  
  static int pcap_open(void *data)
  {
  	struct pcap_data *pri = data;
  	__u32 netmask;
  	int err;

  	if (pri->pcap == NULL)

  		return -ENODEV;

  	if (pri->filter != NULL) {

  		err = dev_netmask(pri->dev, &netmask);

  		if (err < 0) {

  			printk(UM_KERN_ERR "pcap_open : dev_netmask failed
  ");

  			return -EIO;

  		}

  		pri->compiled = uml_kmalloc(sizeof(struct bpf_program),

  					UM_GFP_KERNEL);
  		if (pri->compiled == NULL) {

  			printk(UM_KERN_ERR "pcap_open : kmalloc failed
  ");

  			return -ENOMEM;

  		}

  		err = pcap_compile(pri->pcap,
  				   (struct bpf_program *) pri->compiled,

  				   pri->filter, pri->optimize, netmask);

  		if (err < 0) {

  			printk(UM_KERN_ERR "pcap_open : pcap_compile failed - "
  			       "'%s'
  ", pcap_geterr(pri->pcap));

  			goto out;

  		}
  
  		err = pcap_setfilter(pri->pcap, pri->compiled);

  		if (err < 0) {

  			printk(UM_KERN_ERR "pcap_open : pcap_setfilter "
  			       "failed - '%s'
  ", pcap_geterr(pri->pcap));

  			goto out;

  		}
  	}

  
  	return PCAP_FD(pri->pcap);

  
   out:
  	kfree(pri->compiled);
  	return -EIO;

  }
  
  static void pcap_remove(void *data)
  {
  	struct pcap_data *pri = data;

  	if (pri->compiled != NULL)

  		pcap_freecode(pri->compiled);

  	if (pri->pcap != NULL)

  		pcap_close(pri->pcap);

  }
  
  struct pcap_handler_data {
  	char *buffer;
  	int len;
  };

  static void handler(u_char *data, const struct pcap_pkthdr *header,

  		    const u_char *packet)
  {
  	int len;
  
  	struct pcap_handler_data *hdata = (struct pcap_handler_data *) data;
  
  	len = hdata->len < header->caplen ? hdata->len : header->caplen;
  	memcpy(hdata->buffer, packet, len);
  	hdata->len = len;
  }
  
  int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri)
  {
  	struct pcap_handler_data hdata = ((struct pcap_handler_data)
  		                          { .buffer  	= buffer,
  					    .len 	= len });
  	int n;
  
  	n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata);

  	if (n < 0) {

  		printk(UM_KERN_ERR "pcap_dispatch failed - %s
  ",
  		       pcap_geterr(pri->pcap));

  		return -EIO;

  	}

  	else if (n == 0)

  		return 0;
  	return hdata.len;

  }

  const struct net_user_info pcap_user_info = {

  	.init		= pcap_user_init,
  	.open		= pcap_open,
  	.close	 	= NULL,
  	.remove	 	= pcap_remove,

  	.add_address	= NULL,
  	.delete_address = NULL,

  	.mtu		= ETH_MAX_PACKET,
  	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_OTHER,

  };