1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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 <um_malloc.h>
13
14#define PCAP_FD(p) (*(int *)(p))
15
16static int pcap_user_init(void *data, void *dev)
17{
18	struct pcap_data *pri = data;
19	pcap_t *p;
20	char errors[PCAP_ERRBUF_SIZE];
21
22	p = pcap_open_live(pri->host_if, ETH_MAX_PACKET + ETH_HEADER_OTHER,
23			   pri->promisc, 0, errors);
24	if (p == NULL) {
25		printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - "
26		       "'%s'\n", errors);
27		return -EINVAL;
28	}
29
30	pri->dev = dev;
31	pri->pcap = p;
32	return 0;
33}
34
35static int pcap_user_open(void *data)
36{
37	struct pcap_data *pri = data;
38	__u32 netmask;
39	int err;
40
41	if (pri->pcap == NULL)
42		return -ENODEV;
43
44	if (pri->filter != NULL) {
45		err = dev_netmask(pri->dev, &netmask);
46		if (err < 0) {
47			printk(UM_KERN_ERR "pcap_user_open : dev_netmask failed\n");
48			return -EIO;
49		}
50
51		pri->compiled = uml_kmalloc(sizeof(struct bpf_program),
52					UM_GFP_KERNEL);
53		if (pri->compiled == NULL) {
54			printk(UM_KERN_ERR "pcap_user_open : kmalloc failed\n");
55			return -ENOMEM;
56		}
57
58		err = pcap_compile(pri->pcap,
59				   (struct bpf_program *) pri->compiled,
60				   pri->filter, pri->optimize, netmask);
61		if (err < 0) {
62			printk(UM_KERN_ERR "pcap_user_open : pcap_compile failed - "
63			       "'%s'\n", pcap_geterr(pri->pcap));
64			goto out;
65		}
66
67		err = pcap_setfilter(pri->pcap, pri->compiled);
68		if (err < 0) {
69			printk(UM_KERN_ERR "pcap_user_open : pcap_setfilter "
70			       "failed - '%s'\n", pcap_geterr(pri->pcap));
71			goto out;
72		}
73	}
74
75	return PCAP_FD(pri->pcap);
76
77 out:
78	kfree(pri->compiled);
79	return -EIO;
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_user_open,
131	.close	 	= NULL,
132	.remove	 	= pcap_remove,
133	.add_address	= NULL,
134	.delete_address = NULL,
135	.mtu		= ETH_MAX_PACKET,
136	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_OTHER,
137};
138