1/*
  2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  3 * Licensed under the GPL.
  4 */
  5
  6#include <errno.h>
  7#include <pcap.h>
  8#include <string.h>
  9#include <asm/types.h>
 10#include "net_user.h"
 11#include "pcap_user.h"
 12#include "kern_constants.h"
 13#include "um_malloc.h"
 14#include "user.h"
 15
 16#define PCAP_FD(p) (*(int *)(p))
 17
 18static int pcap_user_init(void *data, void *dev)
 19{
 20	struct pcap_data *pri = data;
 21	pcap_t *p;
 22	char errors[PCAP_ERRBUF_SIZE];
 23
 24	p = pcap_open_live(pri->host_if, ETH_MAX_PACKET + ETH_HEADER_OTHER,
 25			   pri->promisc, 0, errors);
 26	if (p == NULL) {
 27		printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - "
 28		       "'%s'\n", errors);
 29		return -EINVAL;
 30	}
 31
 32	pri->dev = dev;
 33	pri->pcap = p;
 34	return 0;
 35}
 36
 37static int pcap_open(void *data)
 38{
 39	struct pcap_data *pri = data;
 40	__u32 netmask;
 41	int err;
 42
 43	if (pri->pcap == NULL)
 44		return -ENODEV;
 45
 46	if (pri->filter != NULL) {
 47		err = dev_netmask(pri->dev, &netmask);
 48		if (err < 0) {
 49			printk(UM_KERN_ERR "pcap_open : dev_netmask failed\n");
 50			return -EIO;
 51		}
 52
 53		pri->compiled = uml_kmalloc(sizeof(struct bpf_program),
 54					UM_GFP_KERNEL);
 55		if (pri->compiled == NULL) {
 56			printk(UM_KERN_ERR "pcap_open : kmalloc failed\n");
 57			return -ENOMEM;
 58		}
 59
 60		err = pcap_compile(pri->pcap,
 61				   (struct bpf_program *) pri->compiled,
 62				   pri->filter, pri->optimize, netmask);
 63		if (err < 0) {
 64			printk(UM_KERN_ERR "pcap_open : pcap_compile failed - "
 65			       "'%s'\n", pcap_geterr(pri->pcap));
 66			goto out;
 67		}
 68
 69		err = pcap_setfilter(pri->pcap, pri->compiled);
 70		if (err < 0) {
 71			printk(UM_KERN_ERR "pcap_open : pcap_setfilter "
 72			       "failed - '%s'\n", pcap_geterr(pri->pcap));
 73			goto out;
 74		}
 75	}
 76
 77	return PCAP_FD(pri->pcap);
 78
 79 out:
 80	kfree(pri->compiled);
 81	return -EIO;
 82}
 83
 84static void pcap_remove(void *data)
 85{
 86	struct pcap_data *pri = data;
 87
 88	if (pri->compiled != NULL)
 89		pcap_freecode(pri->compiled);
 90
 91	if (pri->pcap != NULL)
 92		pcap_close(pri->pcap);
 93}
 94
 95struct pcap_handler_data {
 96	char *buffer;
 97	int len;
 98};
 99
100static void handler(u_char *data, const struct pcap_pkthdr *header,
101		    const u_char *packet)
102{
103	int len;
104
105	struct pcap_handler_data *hdata = (struct pcap_handler_data *) data;
106
107	len = hdata->len < header->caplen ? hdata->len : header->caplen;
108	memcpy(hdata->buffer, packet, len);
109	hdata->len = len;
110}
111
112int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri)
113{
114	struct pcap_handler_data hdata = ((struct pcap_handler_data)
115		                          { .buffer  	= buffer,
116					    .len 	= len });
117	int n;
118
119	n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata);
120	if (n < 0) {
121		printk(UM_KERN_ERR "pcap_dispatch failed - %s\n",
122		       pcap_geterr(pri->pcap));
123		return -EIO;
124	}
125	else if (n == 0)
126		return 0;
127	return hdata.len;
128}
129
130const struct net_user_info pcap_user_info = {
131	.init		= pcap_user_init,
132	.open		= pcap_open,
133	.close	 	= NULL,
134	.remove	 	= pcap_remove,
135	.add_address	= NULL,
136	.delete_address = NULL,
137	.mtu		= ETH_MAX_PACKET,
138	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_OTHER,
139};