hostap/wlantest/readpcap.c
Jouni Malinen e929eb39d6 wlantest: Add -N command line argument to remove write buffering
This makes it easier to do live parsing of captured pcap files from
wlantest without having to rename and restart the capture file. Packet
writes are flushed to disk after each packet if -N is included in the
command line.

Signed-off-by: Jouni Malinen <j@w1.fi>
2015-11-27 00:10:53 +02:00

189 lines
4.2 KiB
C

/*
* PCAP capture file reader
* Copyright (c) 2010, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#include <pcap.h>
#include "utils/common.h"
#include "wlantest.h"
static void write_pcap_with_radiotap(struct wlantest *wt,
const u8 *data, size_t data_len)
{
struct pcap_pkthdr h;
u8 rtap[] = {
0x00 /* rev */,
0x00 /* pad */,
0x0a, 0x00, /* header len */
0x02, 0x00, 0x00, 0x00, /* present flags */
0x00, /* flags */
0x00 /* pad */
};
u8 *buf;
size_t len;
if (wt->assume_fcs)
rtap[8] |= 0x10;
os_memset(&h, 0, sizeof(h));
h.ts = wt->write_pcap_time;
len = sizeof(rtap) + data_len;
buf = os_malloc(len);
if (buf == NULL)
return;
os_memcpy(buf, rtap, sizeof(rtap));
os_memcpy(buf + sizeof(rtap), data, data_len);
h.caplen = len;
h.len = len;
pcap_dump(wt->write_pcap_dumper, &h, buf);
os_free(buf);
}
int read_cap_file(struct wlantest *wt, const char *fname)
{
char errbuf[PCAP_ERRBUF_SIZE];
pcap_t *pcap;
unsigned int count = 0;
struct pcap_pkthdr *hdr;
const u_char *data;
int res;
int dlt;
pcap = pcap_open_offline(fname, errbuf);
if (pcap == NULL) {
wpa_printf(MSG_ERROR, "Failed to read pcap file '%s': %s",
fname, errbuf);
return -1;
}
dlt = pcap_datalink(pcap);
if (dlt != DLT_IEEE802_11_RADIO && dlt != DLT_PRISM_HEADER &&
dlt != DLT_IEEE802_11) {
wpa_printf(MSG_ERROR, "Unsupported pcap datalink type: %d",
dlt);
pcap_close(pcap);
return -1;
}
wpa_printf(MSG_DEBUG, "pcap datalink type: %d", dlt);
for (;;) {
clear_notes(wt);
os_free(wt->decrypted);
wt->decrypted = NULL;
res = pcap_next_ex(pcap, &hdr, &data);
if (res == -2)
break; /* No more packets */
if (res == -1) {
wpa_printf(MSG_INFO, "pcap_next_ex failure: %s",
pcap_geterr(pcap));
break;
}
if (res != 1) {
wpa_printf(MSG_INFO, "Unexpected pcap_next_ex return "
"value %d", res);
break;
}
/* Packet was read without problems */
wpa_printf(MSG_EXCESSIVE, "pcap hdr: ts=%d.%06d "
"len=%u/%u",
(int) hdr->ts.tv_sec, (int) hdr->ts.tv_usec,
hdr->caplen, hdr->len);
if (wt->write_pcap_dumper) {
wt->write_pcap_time = hdr->ts;
if (dlt == DLT_IEEE802_11)
write_pcap_with_radiotap(wt, data, hdr->caplen);
else
pcap_dump(wt->write_pcap_dumper, hdr, data);
if (wt->pcap_no_buffer)
pcap_dump_flush(wt->write_pcap_dumper);
}
if (hdr->caplen < hdr->len) {
add_note(wt, MSG_DEBUG, "pcap: Dropped incomplete "
"frame (%u/%u captured)",
hdr->caplen, hdr->len);
write_pcapng_write_read(wt, dlt, hdr, data);
continue;
}
count++;
switch (dlt) {
case DLT_IEEE802_11_RADIO:
wlantest_process(wt, data, hdr->caplen);
break;
case DLT_PRISM_HEADER:
wlantest_process_prism(wt, data, hdr->caplen);
break;
case DLT_IEEE802_11:
wlantest_process_80211(wt, data, hdr->caplen);
break;
}
write_pcapng_write_read(wt, dlt, hdr, data);
}
pcap_close(pcap);
wpa_printf(MSG_DEBUG, "Read %s: %u packets", fname, count);
return 0;
}
int read_wired_cap_file(struct wlantest *wt, const char *fname)
{
char errbuf[PCAP_ERRBUF_SIZE];
pcap_t *pcap;
unsigned int count = 0;
struct pcap_pkthdr *hdr;
const u_char *data;
int res;
pcap = pcap_open_offline(fname, errbuf);
if (pcap == NULL) {
wpa_printf(MSG_ERROR, "Failed to read pcap file '%s': %s",
fname, errbuf);
return -1;
}
for (;;) {
res = pcap_next_ex(pcap, &hdr, &data);
if (res == -2)
break; /* No more packets */
if (res == -1) {
wpa_printf(MSG_INFO, "pcap_next_ex failure: %s",
pcap_geterr(pcap));
break;
}
if (res != 1) {
wpa_printf(MSG_INFO, "Unexpected pcap_next_ex return "
"value %d", res);
break;
}
/* Packet was read without problems */
wpa_printf(MSG_EXCESSIVE, "pcap hdr: ts=%d.%06d "
"len=%u/%u",
(int) hdr->ts.tv_sec, (int) hdr->ts.tv_usec,
hdr->caplen, hdr->len);
if (hdr->caplen < hdr->len) {
wpa_printf(MSG_DEBUG, "pcap: Dropped incomplete frame "
"(%u/%u captured)",
hdr->caplen, hdr->len);
continue;
}
count++;
wlantest_process_wired(wt, data, hdr->caplen);
}
pcap_close(pcap);
wpa_printf(MSG_DEBUG, "Read %s: %u packets", fname, count);
return 0;
}