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// SPDX-License-Identifier: LGPL-2.1-or-later
/*
*
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2012-2014 Intel Corporation. All rights reserved.
*
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#define _GNU_SOURCE
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include "src/shared/util.h"
#include "src/shared/pcap.h"
struct pcap_hdr {
uint32_t magic_number; /* magic number */
uint16_t version_major; /* major version number */
uint16_t version_minor; /* minor version number */
int32_t thiszone; /* GMT to local correction */
uint32_t sigfigs; /* accuracy of timestamps */
uint32_t snaplen; /* max length of captured packets, in octets */
uint32_t network; /* data link type */
} __attribute__ ((packed));
#define PCAP_HDR_SIZE (sizeof(struct pcap_hdr))
struct pcap_pkt {
uint32_t ts_sec; /* timestamp seconds */
uint32_t ts_usec; /* timestamp microseconds */
uint32_t incl_len; /* number of octets of packet saved in file */
uint32_t orig_len; /* actual length of packet */
} __attribute__ ((packed));
#define PCAP_PKT_SIZE (sizeof(struct pcap_pkt))
struct pcap_ppi {
uint8_t version; /* version, currently 0 */
uint8_t flags; /* flags */
uint16_t len; /* length of entire message */
uint32_t dlt; /* data link type */
} __attribute__ ((packed));
#define PCAP_PPI_SIZE (sizeof(struct pcap_ppi))
struct pcap {
int ref_count;
int fd;
uint32_t type;
uint32_t snaplen;
};
struct pcap *pcap_open(const char *path)
{
struct pcap *pcap;
struct pcap_hdr hdr;
ssize_t len;
pcap = calloc(1, sizeof(*pcap));
if (!pcap)
return NULL;
pcap->fd = open(path, O_RDONLY | O_CLOEXEC);
if (pcap->fd < 0) {
free(pcap);
return NULL;
}
len = read(pcap->fd, &hdr, PCAP_HDR_SIZE);
if (len < 0 || len != PCAP_HDR_SIZE)
goto failed;
if (hdr.magic_number != 0xa1b2c3d4)
goto failed;
if (hdr.version_major != 2 || hdr.version_minor != 4)
goto failed;
pcap->snaplen = hdr.snaplen;
pcap->type = hdr.network;
return pcap_ref(pcap);
failed:
close(pcap->fd);
free(pcap);
return NULL;
}
struct pcap *pcap_ref(struct pcap *pcap)
{
if (!pcap)
return NULL;
__sync_fetch_and_add(&pcap->ref_count, 1);
return pcap;
}
void pcap_unref(struct pcap *pcap)
{
if (!pcap)
return;
if (__sync_sub_and_fetch(&pcap->ref_count, 1))
return;
if (pcap->fd >= 0)
close(pcap->fd);
free(pcap);
}
uint32_t pcap_get_type(struct pcap *pcap)
{
if (!pcap)
return PCAP_TYPE_INVALID;
return pcap->type;
}
uint32_t pcap_get_snaplen(struct pcap *pcap)
{
if (!pcap)
return 0;
return pcap->snaplen;
}
bool pcap_read(struct pcap *pcap, struct timeval *tv,
void *data, uint32_t size, uint32_t *len)
{
struct pcap_pkt pkt;
uint32_t toread;
ssize_t bytes_read;
if (!pcap)
return false;
bytes_read = read(pcap->fd, &pkt, PCAP_PKT_SIZE);
if (bytes_read != PCAP_PKT_SIZE)
return false;
if (pkt.incl_len > size)
toread = size;
else
toread = pkt.incl_len;
bytes_read = read(pcap->fd, data, toread);
if (bytes_read < 0)
return false;
if (tv) {
tv->tv_sec = pkt.ts_sec;
tv->tv_usec = pkt.ts_usec;
}
if (len)
*len = toread;
return true;
}
bool pcap_read_ppi(struct pcap *pcap, struct timeval *tv, uint32_t *type,
void *data, uint32_t size,
uint32_t *offset, uint32_t *len)
{
struct pcap_pkt pkt;
struct pcap_ppi ppi;
uint16_t pph_len;
uint32_t toread;
ssize_t bytes_read;
if (!pcap)
return false;
bytes_read = read(pcap->fd, &pkt, PCAP_PKT_SIZE);
if (bytes_read != PCAP_PKT_SIZE)
return false;
if (pkt.incl_len > size)
toread = size;
else
toread = pkt.incl_len;
bytes_read = read(pcap->fd, &ppi, PCAP_PPI_SIZE);
if (bytes_read != PCAP_PPI_SIZE)
return false;
if (ppi.flags)
return false;
pph_len = le16_to_cpu(ppi.len);
if (pph_len < PCAP_PPI_SIZE)
return false;
bytes_read = read(pcap->fd, data, toread - PCAP_PPI_SIZE);
if (bytes_read < 0)
return false;
if (tv) {
tv->tv_sec = pkt.ts_sec;
tv->tv_usec = pkt.ts_usec;
}
if (type)
*type = le32_to_cpu(ppi.dlt);
if (offset)
*offset = pph_len - PCAP_PPI_SIZE;
if (len)
*len = toread - pph_len;
return true;
}
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