cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pcap_user.c (3018B)

      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};