17337a736f
With -DDEBUG, passt now saves guest-side traffic captures in pcap format at /tmp/passt_<ISO8601 timestamp>.pcap. The timestamp refers to time and date of start-up. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
108 lines
2 KiB
C
108 lines
2 KiB
C
// SPDX-License-Identifier: AGPL-3.0-or-later
|
|
|
|
/* PASST - Plug A Simple Socket Transport
|
|
*
|
|
* pcap.c - Packet capture for PASST
|
|
*
|
|
* Copyright (c) 2021 Red Hat GmbH
|
|
* Author: Stefano Brivio <sbrivio@redhat.com>
|
|
*
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include <sys/time.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <time.h>
|
|
#include <net/ethernet.h>
|
|
#include <unistd.h>
|
|
|
|
#ifdef DEBUG
|
|
|
|
#define PCAP_PREFIX "/tmp/passt_"
|
|
#define PCAP_ISO8601_FORMAT "%FT%H:%M:%SZ"
|
|
#define PCAP_ISO8601_STR "YYYY-MM-ddTHH:mm:ssZ"
|
|
|
|
#define PCAP_VERSION_MINOR 4
|
|
|
|
static int pcap_fd = 1;
|
|
|
|
/* See pcap.h from libpcap, or pcap-savefile(5) */
|
|
static struct {
|
|
uint32_t magic;
|
|
#define PCAP_MAGIC 0xa1b2c3d4
|
|
|
|
uint16_t major;
|
|
#define PCAP_VERSION_MAJOR 2
|
|
|
|
uint16_t minor;
|
|
#define PCAP_VERSION_MINOR 4
|
|
|
|
int32_t thiszone;
|
|
uint32_t sigfigs;
|
|
uint32_t snaplen;
|
|
|
|
uint32_t linktype;
|
|
#define PCAP_LINKTYPE_ETHERNET 1
|
|
} pcap_hdr = {
|
|
PCAP_MAGIC, PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR, 0, 0, ETH_MAX_MTU,
|
|
PCAP_LINKTYPE_ETHERNET
|
|
};
|
|
|
|
struct pcap_pkthdr {
|
|
uint32_t tv_sec;
|
|
uint32_t tv_usec;
|
|
uint32_t caplen;
|
|
uint32_t len;
|
|
};
|
|
|
|
void pcap(char *pkt, size_t len)
|
|
{
|
|
struct pcap_pkthdr h;
|
|
struct timeval tv;
|
|
|
|
if (pcap_fd == -1)
|
|
return;
|
|
|
|
gettimeofday(&tv, NULL);
|
|
h.tv_sec = tv.tv_sec;
|
|
h.tv_usec = tv.tv_usec;
|
|
h.caplen = h.len = len;
|
|
|
|
write(pcap_fd, &h, sizeof(h));
|
|
write(pcap_fd, pkt, len);
|
|
}
|
|
|
|
void pcap_init(void)
|
|
{
|
|
char name[] = PCAP_PREFIX PCAP_ISO8601_STR ".pcap";
|
|
struct timeval tv;
|
|
struct tm *tm;
|
|
|
|
gettimeofday(&tv, NULL);
|
|
tm = localtime(&tv.tv_sec);
|
|
strftime(name + strlen(PCAP_PREFIX), sizeof(PCAP_ISO8601_STR) - 1,
|
|
PCAP_ISO8601_FORMAT, tm);
|
|
|
|
pcap_fd = open(name, O_WRONLY | O_CREAT | O_APPEND | O_DSYNC,
|
|
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
|
|
if (pcap_fd == -1) {
|
|
perror("open");
|
|
return;
|
|
}
|
|
|
|
write(pcap_fd, &pcap_hdr, sizeof(pcap_hdr));
|
|
}
|
|
|
|
#else /* DEBUG */
|
|
void pcap(char *pkt, size_t len) {
|
|
(void)pkt;
|
|
(void)len;
|
|
}
|
|
|
|
void pcap_init(void) { }
|
|
#endif
|