bluez/tools/btsnoop.c
Łukasz Rymanowski 6ae44c74aa btmon: Fix decoding truncated data
Some platforms use different filtering and for this purpose,
some of the ACL/SCO/ISO/SDP data is truncated.

In such a case, included length is smaller than the original size.
Without this fix, btmon stops working after first truncated packet.
2023-03-14 12:48:46 -07:00

597 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2011-2012 Intel Corporation
* Copyright (C) 2004-2010 Marcel Holtmann <marcel@holtmann.org>
*
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#define _GNU_SOURCE
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <getopt.h>
#include <endian.h>
#include <arpa/inet.h>
#include <sys/stat.h>
#include "src/shared/btsnoop.h"
struct btsnoop_hdr {
uint8_t id[8]; /* Identification Pattern */
uint32_t version; /* Version Number = 1 */
uint32_t type; /* Datalink Type */
} __attribute__ ((packed));
#define BTSNOOP_HDR_SIZE (sizeof(struct btsnoop_hdr))
struct btsnoop_pkt {
uint32_t size; /* Original Length */
uint32_t len; /* Included Length */
uint32_t flags; /* Packet Flags */
uint32_t drops; /* Cumulative Drops */
uint64_t ts; /* Timestamp microseconds */
uint8_t data[0]; /* Packet Data */
} __attribute__ ((packed));
#define BTSNOOP_PKT_SIZE (sizeof(struct btsnoop_pkt))
static const uint8_t btsnoop_id[] = { 0x62, 0x74, 0x73, 0x6e,
0x6f, 0x6f, 0x70, 0x00 };
static const uint32_t btsnoop_version = 1;
static int create_btsnoop(const char *path)
{
struct btsnoop_hdr hdr;
ssize_t written;
int fd;
fd = open(path, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0644);
if (fd < 0) {
perror("failed to output file");
return -1;
}
memcpy(hdr.id, btsnoop_id, sizeof(btsnoop_id));
hdr.version = htobe32(btsnoop_version);
hdr.type = htobe32(2001);
written = write(fd, &hdr, BTSNOOP_HDR_SIZE);
if (written < 0) {
perror("failed to write output header");
close(fd);
return -1;
}
return fd;
}
static int open_btsnoop(const char *path, uint32_t *type)
{
struct btsnoop_hdr hdr;
ssize_t len;
int fd;
fd = open(path, O_RDONLY | O_CLOEXEC);
if (fd < 0) {
perror("failed to open input file");
return -1;
}
len = read(fd, &hdr, BTSNOOP_HDR_SIZE);
if (len < 0 || len != BTSNOOP_HDR_SIZE) {
perror("failed to read input header");
close(fd);
return -1;
}
if (memcmp(hdr.id, btsnoop_id, sizeof(btsnoop_id))) {
fprintf(stderr, "not a valid btsnoop header\n");
close(fd);
return -1;
}
if (be32toh(hdr.version) != btsnoop_version) {
fprintf(stderr, "invalid btsnoop version\n");
close(fd);
return -1;
}
if (type)
*type = be32toh(hdr.type);
return fd;
}
#define MAX_MERGE 8
static void command_merge(const char *output, int argc, char *argv[])
{
struct btsnoop_pkt input_pkt[MAX_MERGE];
unsigned char buf[2048];
int output_fd, input_fd[MAX_MERGE], num_input = 0;
int i, select_input;
ssize_t len, written;
uint32_t toread, flags;
uint16_t index, opcode;
if (argc > MAX_MERGE) {
fprintf(stderr, "only up to %d files allowed\n", MAX_MERGE);
return;
}
for (i = 0; i < argc; i++) {
uint32_t type;
int fd;
fd = open_btsnoop(argv[i], &type);
if (fd < 0)
break;
if (type != 1002) {
fprintf(stderr, "unsupported link data type %u\n",
type);
close(fd);
break;
}
input_fd[num_input++] = fd;
}
if (num_input != argc) {
fprintf(stderr, "failed to open all input files\n");
goto close_input;
}
output_fd = create_btsnoop(output);
if (output_fd < 0)
goto close_input;
for (i = 0; i < num_input; i++) {
len = read(input_fd[i], &input_pkt[i], BTSNOOP_PKT_SIZE);
if (len < 0 || len != BTSNOOP_PKT_SIZE) {
close(input_fd[i]);
input_fd[i] = -1;
}
}
next_packet:
select_input = -1;
for (i = 0; i < num_input; i++) {
uint64_t ts;
if (input_fd[i] < 0)
continue;
if (select_input < 0) {
select_input = i;
continue;
}
ts = be64toh(input_pkt[i].ts);
if (ts < be64toh(input_pkt[select_input].ts))
select_input = i;
}
if (select_input < 0)
goto close_output;
toread = be32toh(input_pkt[select_input].size);
flags = be32toh(input_pkt[select_input].flags);
len = read(input_fd[select_input], buf, toread);
if (toread == 0 || len < 0 || len != (ssize_t) toread) {
close(input_fd[select_input]);
input_fd[select_input] = -1;
goto next_packet;
}
written = htobe32(toread - 1);
input_pkt[select_input].size = written;
input_pkt[select_input].len = written;
switch (buf[0]) {
case 0x01:
opcode = BTSNOOP_OPCODE_COMMAND_PKT;
break;
case 0x02:
if (flags & 0x01)
opcode = BTSNOOP_OPCODE_ACL_RX_PKT;
else
opcode = BTSNOOP_OPCODE_ACL_TX_PKT;
break;
case 0x03:
if (flags & 0x01)
opcode = BTSNOOP_OPCODE_SCO_RX_PKT;
else
opcode = BTSNOOP_OPCODE_SCO_TX_PKT;
break;
case 0x04:
opcode = BTSNOOP_OPCODE_EVENT_PKT;
break;
default:
goto skip_write;
}
index = select_input;
input_pkt[select_input].flags = htobe32((index << 16) | opcode);
written = write(output_fd, &input_pkt[select_input], BTSNOOP_PKT_SIZE);
if (written != BTSNOOP_PKT_SIZE) {
fprintf(stderr, "write of packet header failed\n");
goto close_output;
}
written = write(output_fd, buf + 1, toread - 1);
if (written != (ssize_t) toread - 1) {
fprintf(stderr, "write of packet data failed\n");
goto close_output;
}
skip_write:
len = read(input_fd[select_input],
&input_pkt[select_input], BTSNOOP_PKT_SIZE);
if (len < 0 || len != BTSNOOP_PKT_SIZE) {
close(input_fd[select_input]);
input_fd[select_input] = -1;
}
goto next_packet;
close_output:
close(output_fd);
close_input:
for (i = 0; i < num_input; i++)
close(input_fd[i]);
}
static void command_extract_eir(const char *input)
{
struct btsnoop_pkt pkt;
unsigned char buf[2048];
ssize_t len;
uint32_t type, toread, flags;
uint16_t opcode;
int fd, count = 0;
fd = open_btsnoop(input, &type);
if (fd < 0)
return;
if (type != 2001) {
fprintf(stderr, "unsupported link data type %u\n", type);
close(fd);
return;
}
next_packet:
len = read(fd, &pkt, BTSNOOP_PKT_SIZE);
if (len < 0 || len != BTSNOOP_PKT_SIZE)
goto close_input;
toread = be32toh(pkt.len);
flags = be32toh(pkt.flags);
opcode = flags & 0x00ff;
len = read(fd, buf, toread);
if (len < 0 || len != (ssize_t) toread) {
fprintf(stderr, "failed to read packet data\n");
goto close_input;
}
switch (opcode) {
case BTSNOOP_OPCODE_EVENT_PKT:
/* extended inquiry result event */
if (buf[0] == 0x2f) {
uint8_t *eir_ptr, eir_len, i;
eir_len = buf[1] - 15;
eir_ptr = buf + 17;
if (eir_len < 1 || eir_len > 240)
break;
printf("\t[Extended Inquiry Data with %u bytes]\n",
eir_len);
printf("\t\t");
for (i = 0; i < eir_len; i++) {
printf("0x%02x", eir_ptr[i]);
if (((i + 1) % 8) == 0) {
if (i < eir_len - 1)
printf(",\n\t\t");
} else {
if (i < eir_len - 1)
printf(", ");
}
}
printf("\n");
count++;
}
break;
}
goto next_packet;
close_input:
close(fd);
}
static void command_extract_ad(const char *input)
{
struct btsnoop_pkt pkt;
unsigned char buf[2048];
ssize_t len;
uint32_t type, toread, flags;
uint16_t opcode;
int fd, count = 0;
fd = open_btsnoop(input, &type);
if (fd < 0)
return;
if (type != 2001) {
fprintf(stderr, "unsupported link data type %u\n", type);
close(fd);
return;
}
next_packet:
len = read(fd, &pkt, BTSNOOP_PKT_SIZE);
if (len < 0 || len != BTSNOOP_PKT_SIZE)
goto close_input;
toread = be32toh(pkt.len);
flags = be32toh(pkt.flags);
opcode = flags & 0x00ff;
len = read(fd, buf, toread);
if (len < 0 || len != (ssize_t) toread) {
fprintf(stderr, "failed to read packet data\n");
goto close_input;
}
switch (opcode) {
case BTSNOOP_OPCODE_EVENT_PKT:
/* advertising report */
if (buf[0] == 0x3e && buf[2] == 0x02) {
uint8_t *ad_ptr, ad_len, i;
ad_len = buf[12];
ad_ptr = buf + 13;
if (ad_len < 1 || ad_len > 40)
break;
printf("\t[Advertising Data with %u bytes]\n", ad_len);
printf("\t\t");
for (i = 0; i < ad_len; i++) {
printf("0x%02x", ad_ptr[i]);
if (((i + 1) % 8) == 0) {
if (i < ad_len - 1)
printf(",\n\t\t");
} else {
if (i < ad_len - 1)
printf(", ");
}
}
printf("\n");
count++;
}
break;
}
goto next_packet;
close_input:
close(fd);
}
static const uint8_t conn_complete[] = { 0x04, 0x03, 0x0B, 0x00 };
static const uint8_t disc_complete[] = { 0x04, 0x05, 0x04, 0x00 };
static void command_extract_sdp(const char *input)
{
struct btsnoop_pkt pkt;
unsigned char buf[2048];
ssize_t len;
uint32_t type, toread;
uint16_t current_cid = 0x0000;
uint8_t pdu_buf[512];
uint16_t pdu_len = 0;
bool pdu_first = false;
int fd, count = 0;
fd = open_btsnoop(input, &type);
if (fd < 0)
return;
if (type != 1002) {
fprintf(stderr, "unsupported link data type %u\n", type);
close(fd);
return;
}
next_packet:
len = read(fd, &pkt, BTSNOOP_PKT_SIZE);
if (len < 0 || len != BTSNOOP_PKT_SIZE)
goto close_input;
toread = be32toh(pkt.len);
len = read(fd, buf, toread);
if (len < 0 || len != (ssize_t) toread) {
fprintf(stderr, "failed to read packet data\n");
goto close_input;
}
if (buf[0] == 0x02) {
uint8_t acl_flags;
/* first 4 bytes are handle and data len */
acl_flags = buf[2] >> 4;
/* use only packet with ACL start flag */
if (acl_flags & 0x02) {
if (current_cid == 0x0040 && pdu_len > 0) {
int i;
if (!pdu_first)
printf(",\n");
printf("\t\traw_pdu(");
for (i = 0; i < pdu_len; i++) {
printf("0x%02x", pdu_buf[i]);
if (((i + 1) % 8) == 0) {
if (i < pdu_len - 1)
printf(",\n\t\t\t");
} else {
if (i < pdu_len - 1)
printf(", ");
}
}
printf(")");
pdu_first = false;
}
/* next 4 bytes are data len and cid */
current_cid = buf[8] << 8 | buf[7];
memcpy(pdu_buf, buf + 9, len - 9);
pdu_len = len - 9;
} else if (acl_flags & 0x01) {
memcpy(pdu_buf + pdu_len, buf + 5, len - 5);
pdu_len += len - 5;
}
}
if ((size_t) len > sizeof(conn_complete)) {
if (memcmp(buf, conn_complete, sizeof(conn_complete)) == 0) {
printf("\tdefine_test(\"/test/%u\",\n", ++count);
pdu_first = true;
}
}
if ((size_t) len > sizeof(disc_complete)) {
if (memcmp(buf, disc_complete, sizeof(disc_complete)) == 0) {
printf(");\n");
}
}
goto next_packet;
close_input:
close(fd);
}
static void usage(void)
{
printf("btsnoop trace file handling tool\n"
"Usage:\n");
printf("\tbtsnoop <command> [files]\n");
printf("commands:\n"
"\t-m, --merge <output> Merge multiple btsnoop files\n"
"\t-e, --extract <input> Extract data from btsnoop file\n"
"\t-h, --help Show help options\n");
}
static const struct option main_options[] = {
{ "merge", required_argument, NULL, 'm' },
{ "extract", required_argument, NULL, 'e' },
{ "type", required_argument, NULL, 't' },
{ "version", no_argument, NULL, 'v' },
{ "help", no_argument, NULL, 'h' },
{ }
};
enum { INVALID, MERGE, EXTRACT };
int main(int argc, char *argv[])
{
const char *output_path = NULL;
const char *input_path = NULL;
const char *type = NULL;
unsigned short command = INVALID;
for (;;) {
int opt;
opt = getopt_long(argc, argv, "m:e:t:vh", main_options, NULL);
if (opt < 0)
break;
switch (opt) {
case 'm':
command = MERGE;
output_path = optarg;
break;
case 'e':
command = EXTRACT;
input_path = optarg;
break;
case 't':
type = optarg;
break;
case 'v':
printf("%s\n", VERSION);
return EXIT_SUCCESS;
case 'h':
usage();
return EXIT_SUCCESS;
default:
return EXIT_FAILURE;
}
}
switch (command) {
case MERGE:
if (argc - optind < 1) {
fprintf(stderr, "input files required\n");
return EXIT_FAILURE;
}
command_merge(output_path, argc - optind, argv + optind);
break;
case EXTRACT:
if (argc - optind > 0) {
fprintf(stderr, "extra arguments not allowed\n");
return EXIT_FAILURE;
}
if (!type) {
fprintf(stderr, "no extract type specified\n");
return EXIT_FAILURE;
}
if (!strcasecmp(type, "eir"))
command_extract_eir(input_path);
else if (!strcasecmp(type, "ad"))
command_extract_ad(input_path);
else if (!strcasecmp(type, "sdp"))
command_extract_sdp(input_path);
else
fprintf(stderr, "extract type not supported\n");
break;
default:
usage();
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}