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