[PATCH v2 1/4] lib: Add monitor.h

[PATCH v2 1/4] lib: Add monitor.h

[Szymon Janc]

This is to separate monitor and control channels.
---
 lib/monitor.h | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 lib/monitor.h

diff --git a/lib/monitor.h b/lib/monitor.h
new file mode 100644
index 000000000..34c3cc7fb
--- /dev/null
+++ b/lib/monitor.h
@@ -0,0 +1,34 @@
+/*
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2010  Nokia Corporation
+ *  Copyright (C) 2010  Marcel Holtmann <marcel@holtmann.org>
+ *
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifndef __packed
+#define __packed __attribute__((packed))
+#endif
+
+#define MONITOR_INDEX_NONE 0xffff
+
+struct monitor_hdr {
+	uint16_t opcode;
+	uint16_t index;
+	uint16_t len;
+} __packed;
-- 
2.14.3

[PATCH v2 2/4] tools: Add initial code for btmon-logger

[Szymon Janc]

This is intended for use for automted logging or unatrended systems.
It doesn't contain any packet decoding functionality which results
in much smaller binary.
---
 .gitignore           |   1 +
 Makefile.tools       |   5 +
 tools/btmon-logger.c | 343 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 349 insertions(+)
 create mode 100644 tools/btmon-logger.c

diff --git a/.gitignore b/.gitignore
index 47808059b..33ec66048 100644
--- a/.gitignore
+++ b/.gitignore
@@ -118,6 +118,7 @@ tools/btconfig
 tools/btmgmt
 tools/btsnoop
 tools/btpclient
+tools/btmon-logger
 peripheral/btsensor
 monitor/btmon
 emulator/btvirt
diff --git a/Makefile.tools b/Makefile.tools
index 71d083e71..ba4b9b7d7 100644
--- a/Makefile.tools
+++ b/Makefile.tools
@@ -62,6 +62,11 @@ monitor_btmon_SOURCES = monitor/main.c monitor/bt.h \
 				monitor/tty.h
 monitor_btmon_LDADD = lib/libbluetooth-internal.la \
 				src/libshared-mainloop.la @UDEV_LIBS@
+
+noinst_PROGRAMS += tools/btmon-logger
+
+tools_btmon_logger_SOURCES = tools/btmon-logger.c lib/monitor.h
+tools_btmon_logger_LDADD = src/libshared-mainloop.la
 endif
 
 if TESTING
diff --git a/tools/btmon-logger.c b/tools/btmon-logger.c
new file mode 100644
index 000000000..428cd3ff2
--- /dev/null
+++ b/tools/btmon-logger.c
@@ -0,0 +1,343 @@
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2017  Codecoup
+ *  Copyright (C) 2011-2014  Intel Corporation
+ *  Copyright (C) 2002-2010  Marcel Holtmann <marcel@holtmann.org>
+ *
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <string.h>
+#include <time.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <sys/socket.h>
+
+#include "lib/bluetooth.h"
+#include "lib/hci.h"
+#include "lib/monitor.h"
+
+#include "src/shared/util.h"
+#include "src/shared/mainloop.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 char *path = ".";
+static const char *prefix = "hci";
+static bool suffix_date = false;
+static size_t write_limit = 0;
+static size_t write_size = 0;
+
+static struct btsnoop *btsnoop_file = NULL;
+
+static bool create_btsnoop(void)
+{
+	static char real_path[FILENAME_MAX];
+	struct timeval tv;
+
+	gettimeofday(&tv, NULL);
+
+	if (suffix_date) {
+		struct tm tm;
+
+		localtime_r(&tv.tv_sec, &tm);
+
+		snprintf(real_path, FILENAME_MAX,
+				"%s/%s_%04d-%02d-%02d_%02d:%02d:%02d.btsnoop",
+				path, prefix, tm.tm_year + 1900, tm.tm_mon + 1,
+				tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
+	} else {
+		static unsigned int cnt = 0;
+
+		snprintf(real_path, sizeof(real_path), "%s/%s_%u.btsnoop",
+							path, prefix, cnt++);
+	}
+
+	btsnoop_file = btsnoop_create(real_path, BTSNOOP_FORMAT_MONITOR);
+	if(!btsnoop_file)
+		return false;
+
+	write_size = BTSNOOP_HDR_SIZE;
+
+	return true;
+}
+
+static void rotate_btsnoop(uint16_t pktlen)
+{
+	write_size += BTSNOOP_PKT_SIZE + pktlen;
+
+	if (write_size <= write_limit)
+		return;
+
+	btsnoop_unref(btsnoop_file);
+
+	if (!create_btsnoop()) {
+		fprintf(stderr, "Failed to create btsnoop file, exiting.\n");
+		mainloop_quit();
+		return;
+	}
+
+	write_size += BTSNOOP_PKT_SIZE + pktlen;
+}
+
+static void data_callback(int fd, uint32_t events, void *user_data)
+{
+	uint8_t buf[BTSNOOP_MAX_PACKET_SIZE];
+	unsigned char control[64];
+	struct monitor_hdr hdr;
+	struct msghdr msg;
+	struct iovec iov[2];
+
+	if (events & (EPOLLERR | EPOLLHUP)) {
+		mainloop_remove_fd(fd);
+		return;
+	}
+
+	iov[0].iov_base = &hdr;
+	iov[0].iov_len = sizeof(hdr);
+	iov[1].iov_base = buf;
+	iov[1].iov_len = sizeof(buf);
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_iov = iov;
+	msg.msg_iovlen = 2;
+	msg.msg_control = control;
+	msg.msg_controllen = sizeof(control);
+
+	while (1) {
+		struct cmsghdr *cmsg;
+		struct timeval *tv = NULL;
+		struct timeval ctv;
+		uint16_t opcode, index, pktlen;
+		ssize_t len;
+
+		len = recvmsg(fd, &msg, MSG_DONTWAIT);
+		if (len < 0)
+			break;
+
+		if (len < (ssize_t) sizeof(hdr))
+			break;
+
+		for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
+					cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+			if (cmsg->cmsg_level != SOL_SOCKET)
+				continue;
+
+			if (cmsg->cmsg_type == SCM_TIMESTAMP) {
+				memcpy(&ctv, CMSG_DATA(cmsg), sizeof(ctv));
+				tv = &ctv;
+			}
+		}
+
+		opcode = le16_to_cpu(hdr.opcode);
+		index  = le16_to_cpu(hdr.index);
+		pktlen = le16_to_cpu(hdr.len);
+
+		if (write_limit)
+			rotate_btsnoop(pktlen);
+
+		btsnoop_write_hci(btsnoop_file, tv, index, opcode, 0, buf,
+									pktlen);
+	}
+}
+
+static bool open_monitor_channel(void)
+{
+	struct sockaddr_hci addr;
+	int fd, opt = 1;
+
+	fd = socket(AF_BLUETOOTH, SOCK_RAW | SOCK_CLOEXEC, BTPROTO_HCI);
+	if (fd < 0) {
+		perror("Failed to open monitor channel");
+		return false;
+	}
+
+	memset(&addr, 0, sizeof(addr));
+	addr.hci_family = AF_BLUETOOTH;
+	addr.hci_dev = HCI_DEV_NONE;
+	addr.hci_channel = HCI_CHANNEL_MONITOR;
+
+	if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
+		perror("Failed to bind monitor channel");
+		close(fd);
+		return false;
+	}
+
+	if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) {
+		perror("Failed to enable timestamps");
+		close(fd);
+		return false;
+	}
+
+	if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &opt, sizeof(opt)) < 0) {
+		perror("Failed to enable credentials");
+		close(fd);
+		return false;
+	}
+
+	mainloop_add_fd(fd, EPOLLIN, data_callback, NULL, NULL);
+
+	return true;
+}
+
+static void signal_callback(int signum, void *user_data)
+{
+	switch (signum) {
+	case SIGINT:
+	case SIGTERM:
+		mainloop_quit();
+		break;
+	}
+}
+
+static void usage(void)
+{
+	printf("btmon-logger - Bluetooth monitor\n"
+		"Usage:\n");
+	printf("\tbtmon-logger [options]\n");
+	printf("options:\n"
+		"\t-p, --path <path>      Save traces in specified path\n"
+		"\t-P, --prefix <name>    Prefix filenames (defaults: \"hci\"\n"
+		"\t-d, --date             Suffix filenames with date\n"
+		"\t-l, --limit <limit>    Limit btsnoop file size (rotate)\n"
+		"\t-v, --version          Show version\n"
+		"\t-h, --help             Show help options\n");
+}
+
+static const struct option main_options[] = {
+	{ "path",	required_argument,	NULL, 'p' },
+	{ "prefix",	required_argument,	NULL, 'P' },
+	{ "date",	no_argument,		NULL, 'd' },
+	{ "limit",	required_argument,	NULL, 'l' },
+	{ "version",	no_argument,		NULL, 'v' },
+	{ "help",	no_argument,		NULL, 'h' },
+	{ }
+};
+
+int main(int argc, char *argv[])
+{
+	sigset_t mask;
+	char *endptr;
+	int ret;
+
+	mainloop_init();
+
+	while (true) {
+		int opt;
+
+		opt = getopt_long(argc, argv, "p:P:dl:Lvh", main_options,
+									NULL);
+		if (opt < 0)
+			break;
+
+		switch (opt) {
+		case 'p':
+			path = optarg;
+			if (strlen(path) > PATH_MAX) {
+				fprintf(stderr, "Too long path\n");
+				return EXIT_FAILURE;
+			}
+			break;
+		case 'P':
+			prefix = optarg;
+			break;
+		case 'd':
+			suffix_date = true;
+			break;
+		case 'l':
+			write_limit = strtoul(optarg, &endptr, 10);
+
+			if (write_limit == ULONG_MAX) {
+				fprintf(stderr, "Invalid limit\n");
+				return EXIT_FAILURE;
+			}
+
+			if (*endptr != '\0') {
+				if (*endptr == 'K' || *endptr == 'k') {
+					write_limit *= 1024;
+				} else if (*endptr == 'M' || *endptr == 'm') {
+					write_limit *= 1024 * 1024;
+				} else {
+					fprintf(stderr, "Invalid limit\n");
+					return EXIT_FAILURE;
+				}
+			}
+
+			/* limit this to reasonable size */
+			if (write_limit < 4096) {
+				fprintf(stderr, "Too small limit value\n");
+				return EXIT_FAILURE;
+			}
+			break;
+		case 'v':
+			printf("%s\n", VERSION);
+			return EXIT_SUCCESS;
+		case 'h':
+			usage();
+			return EXIT_SUCCESS;
+		default:
+			return EXIT_FAILURE;
+		}
+	}
+
+	if (argc - optind > 0) {
+		fprintf(stderr, "Invalid command line parameters\n");
+		return EXIT_FAILURE;
+	}
+
+	if (!open_monitor_channel() || !create_btsnoop())
+		return EXIT_FAILURE;
+
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGINT);
+	sigaddset(&mask, SIGTERM);
+
+	mainloop_set_signal(&mask, signal_callback, NULL, NULL);
+
+	printf("Bluetooth monitor ver %s\n", VERSION);
+
+	ret = mainloop_run();
+
+	btsnoop_unref(btsnoop_file);
+
+	return ret;
+}
-- 
2.14.3

[PATCH v2 3/4] tools/btmon-logger: Add support for chainning snoop files

[Szymon Janc]

This allows to generate split btsnoop file (eg for log rotation). To
achieve that new opcode is added to btsnoop file format. This opcode
contains random Set ID and sequence number which are used to identyfing
files and set. This special opcode is always first opcode in btsnoop
file that is part of a set.
---
 src/shared/btsnoop.h |  6 ++++++
 tools/btmon-logger.c | 26 +++++++++++++++++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/shared/btsnoop.h b/src/shared/btsnoop.h
index 3df8998a3..a26d0a147 100644
--- a/src/shared/btsnoop.h
+++ b/src/shared/btsnoop.h
@@ -53,6 +53,7 @@
 #define BTSNOOP_OPCODE_CTRL_CLOSE	15
 #define BTSNOOP_OPCODE_CTRL_COMMAND	16
 #define BTSNOOP_OPCODE_CTRL_EVENT	17
+#define BTSNOOP_OPCODE_SET_ID		18
 
 #define BTSNOOP_MAX_PACKET_SIZE		(1486 + 4)
 
@@ -96,6 +97,11 @@ struct btsnoop_opcode_user_logging {
 	uint8_t  ident_len;
 } __attribute__((packed));
 
+struct btsnoop_opcode_set_id {
+	uint8_t id[16];
+	uint32_t seq;
+} __attribute__((packed));
+
 struct btsnoop;
 
 struct btsnoop *btsnoop_open(const char *path, unsigned long flags);
diff --git a/tools/btmon-logger.c b/tools/btmon-logger.c
index 428cd3ff2..34afc0d4b 100644
--- a/tools/btmon-logger.c
+++ b/tools/btmon-logger.c
@@ -35,6 +35,7 @@
 #include <getopt.h>
 #include <unistd.h>
 #include <sys/socket.h>
+#include <sys/random.h>
 
 #include "lib/bluetooth.h"
 #include "lib/hci.h"
@@ -69,6 +70,9 @@ static size_t write_size = 0;
 
 static struct btsnoop *btsnoop_file = NULL;
 
+static uint8_t set_random_id[16];
+static uint32_t set_seq = 0;
+
 static bool create_btsnoop(void)
 {
 	static char real_path[FILENAME_MAX];
@@ -86,10 +90,8 @@ static bool create_btsnoop(void)
 				path, prefix, tm.tm_year + 1900, tm.tm_mon + 1,
 				tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
 	} else {
-		static unsigned int cnt = 0;
-
 		snprintf(real_path, sizeof(real_path), "%s/%s_%u.btsnoop",
-							path, prefix, cnt++);
+							path, prefix, set_seq);
 	}
 
 	btsnoop_file = btsnoop_create(real_path, BTSNOOP_FORMAT_MONITOR);
@@ -98,6 +100,21 @@ static bool create_btsnoop(void)
 
 	write_size = BTSNOOP_HDR_SIZE;
 
+	if (write_limit) {
+		struct btsnoop_opcode_set_id op;
+		uint32_t flags;
+
+		memcpy(&op.id, set_random_id, sizeof(op.id));
+		op.seq = cpu_to_be32(set_seq);
+
+		flags = (MONITOR_INDEX_NONE << 16) | BTSNOOP_OPCODE_SET_ID;
+
+		btsnoop_write(btsnoop_file, &tv, flags, 0, &op, sizeof(op));
+
+		set_seq++;
+		write_size += BTSNOOP_PKT_SIZE + sizeof(op);
+	}
+
 	return true;
 }
 
@@ -324,6 +341,9 @@ int main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
+	if (write_limit)
+		getrandom(set_random_id, sizeof(set_random_id), 0);
+
 	if (!open_monitor_channel() || !create_btsnoop())
 		return EXIT_FAILURE;
 
-- 
2.14.3

[PATCH v2 4/4] monitor: Add support for reading btsnoop sets

[Szymon Janc]

This allows to combine multiple btsnoop files for decoding. Files need
to be from same set (share same ID) and sequence numbers must be without
gaps. First file doesn't have to have sequence 0.
---
 monitor/control.c | 139 +++++++++++++++++++++++++++++++++++++++++++++++++-----
 monitor/control.h |   2 +-
 monitor/main.c    |  20 ++++++--
 monitor/packet.c  |   1 +
 4 files changed, 145 insertions(+), 17 deletions(-)

diff --git a/monitor/control.c b/monitor/control.c
index 1cd79ca5d..a1a2415b9 100644
--- a/monitor/control.c
+++ b/monitor/control.c
@@ -45,6 +45,7 @@
 #include "lib/mgmt.h"
 
 #include "src/shared/util.h"
+#include "src/shared/queue.h"
 #include "src/shared/btsnoop.h"
 #include "src/shared/mainloop.h"
 
@@ -1378,18 +1379,14 @@ bool control_writer(const char *path)
 	return !!btsnoop_file;
 }
 
-void control_reader(const char *path)
+static void parse_snoop(struct btsnoop *btsnoop)
 {
 	unsigned char buf[BTSNOOP_MAX_PACKET_SIZE];
 	uint16_t pktlen;
 	uint32_t format;
 	struct timeval tv;
 
-	btsnoop_file = btsnoop_open(path, BTSNOOP_FLAG_PKLG_SUPPORT);
-	if (!btsnoop_file)
-		return;
-
-	format = btsnoop_get_format(btsnoop_file);
+	format = btsnoop_get_format(btsnoop);
 
 	switch (format) {
 	case BTSNOOP_FORMAT_HCI:
@@ -1403,8 +1400,6 @@ void control_reader(const char *path)
 		break;
 	}
 
-	open_pager();
-
 	switch (format) {
 	case BTSNOOP_FORMAT_HCI:
 	case BTSNOOP_FORMAT_UART:
@@ -1412,7 +1407,7 @@ void control_reader(const char *path)
 		while (1) {
 			uint16_t index, opcode;
 
-			if (!btsnoop_read_hci(btsnoop_file, &tv, &index,
+			if (!btsnoop_read_hci(btsnoop, &tv, &index,
 							&opcode, buf, &pktlen))
 				break;
 
@@ -1428,7 +1423,7 @@ void control_reader(const char *path)
 		while (1) {
 			uint16_t frequency;
 
-			if (!btsnoop_read_phy(btsnoop_file, &tv, &frequency,
+			if (!btsnoop_read_phy(btsnoop, &tv, &frequency,
 								buf, &pktlen))
 				break;
 
@@ -1436,10 +1431,132 @@ void control_reader(const char *path)
 		}
 		break;
 	}
+}
+
+struct snoop_data
+{
+	struct btsnoop *snoop;
+	uint32_t seq;
+};
+
+static void snoop_data_free(void *data)
+{
+	struct snoop_data *snoop_data = data;
+
+	btsnoop_unref(snoop_data->snoop);
+	free(snoop_data);
+}
+
+static bool match_snoop_by_seq(const void *data, const void *match_data)
+{
+	const struct snoop_data *snoop_data = data;
+	uint32_t seq = PTR_TO_UINT(match_data);
+
+	return snoop_data->seq == seq;
+}
+
+void control_reader(struct queue *paths)
+{
+	const struct queue_entry *entry;
+	struct snoop_data *data;
+	struct btsnoop *snoop;
+	struct queue *snoops;
+	uint8_t id[16];
+	bool first = true;
+	uint32_t i;
+
+	/* if 1 file is provided we don't check for set and seq and sort */
+	if (queue_length(paths) == 1) {
+		snoop = btsnoop_open(queue_pop_head(paths),
+						BTSNOOP_FLAG_PKLG_SUPPORT);
+		if (snoop) {
+			open_pager();
+			parse_snoop(snoop);
+			close_pager();
+		}
+
+		return;
+	}
+
+	snoops = queue_new();
+
+	/* get all snoop files with seq and verify set ID */
+	for (entry = queue_get_entries(paths); entry; entry = entry->next) {
+		unsigned char buf[BTSNOOP_MAX_PACKET_SIZE];
+		struct btsnoop_opcode_set_id *pkt = (void *)buf;
+		struct timeval tv;
+		uint16_t index;
+		uint16_t opcode;
+		uint16_t len;
+
+		snoop = btsnoop_open(entry->data, BTSNOOP_FLAG_PKLG_SUPPORT);
+		if (!snoop) {
+			fprintf(stderr, "Failed to open %s\n",
+							(char *) entry->data);
+			goto done;
+		}
+
+		if (!btsnoop_read_hci(snoop, &tv, &index, &opcode, buf, &len)) {
+			fprintf(stderr, "Failed to to read seq for %s\n",
+							(char *) entry->data);
+			goto done;
+		}
+
+		if (opcode != BTSNOOP_OPCODE_SET_ID) {
+			fprintf(stderr, "Set ID missing for %s\n",
+						(char *) entry->data);
+			goto done;
+		}
+
+		if (len != sizeof (*pkt)) {
+			fprintf(stderr, "Invalid Set ID size for %s\n",
+						(char *) entry->data);
+			goto done;
+		}
+
+		if (first) {
+			memcpy(id, pkt->id, sizeof(id));
+			first = false;
+		} else {
+			if (memcmp(id, pkt->id, sizeof(id))) {
+				fprintf(stderr, "Set ID mismatch for %s\n",
+							(char *) entry->data);
+				goto done;
+			}
+		}
+
+		data = new0(struct snoop_data, 1);
+		data->snoop = snoop;
+		data->seq = be32_to_cpu(pkt->seq);
+
+		queue_push_tail(snoops, data);
+	}
+
+	open_pager();
+
+	first = true;
+	for (i = 0; i < UINT32_MAX; i++) {
+		data = queue_remove_if(snoops, match_snoop_by_seq,
+								UINT_TO_PTR(i));
+
+		if (data) {
+			first = false;
+			parse_snoop(data->snoop);
+			snoop_data_free(data);
+			continue;
+		}
+
+		if (!queue_isempty(snoops))
+			printf("File with next sequence %u missing, stopping\n",
+									i);
+
+		break;
+	}
 
 	close_pager();
 
-	btsnoop_unref(btsnoop_file);
+done:
+	queue_destroy(snoops, snoop_data_free);
 }
 
 int control_tracing(void)
diff --git a/monitor/control.h b/monitor/control.h
index 630a852e4..85a7913b0 100644
--- a/monitor/control.h
+++ b/monitor/control.h
@@ -25,7 +25,7 @@
 #include <stdint.h>
 
 bool control_writer(const char *path);
-void control_reader(const char *path);
+void control_reader(struct queue *paths);
 void control_server(const char *path);
 int control_tty(const char *path, unsigned int speed);
 int control_tracing(void);
diff --git a/monitor/main.c b/monitor/main.c
index 3e61a4661..0102103df 100644
--- a/monitor/main.c
+++ b/monitor/main.c
@@ -33,6 +33,7 @@
 #include <getopt.h>
 #include <sys/un.h>
 
+#include "src/shared/queue.h"
 #include "src/shared/mainloop.h"
 #include "src/shared/tty.h"
 
@@ -97,8 +98,8 @@ static const struct option main_options[] = {
 
 int main(int argc, char *argv[])
 {
+	struct queue *reader_paths = queue_new();
 	unsigned long filter_mask = 0;
-	const char *reader_path = NULL;
 	const char *writer_path = NULL;
 	const char *analyze_path = NULL;
 	const char *ellisys_server = NULL;
@@ -134,7 +135,12 @@ int main(int argc, char *argv[])
 			}
 			break;
 		case 'r':
-			reader_path = optarg;
+			queue_push_tail(reader_paths, optarg);
+
+			/* check if more paths were provided */
+			while (optind < argc && *argv[optind] != '-')
+				queue_push_tail(reader_paths, argv[optind++]);
+
 			break;
 		case 'w':
 			writer_path = optarg;
@@ -202,7 +208,7 @@ int main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
-	if (reader_path && analyze_path) {
+	if (!queue_isempty(reader_paths) && analyze_path) {
 		fprintf(stderr, "Display and analyze can't be combined\n");
 		return EXIT_FAILURE;
 	}
@@ -224,14 +230,18 @@ int main(int argc, char *argv[])
 		return EXIT_SUCCESS;
 	}
 
-	if (reader_path) {
+	if (!queue_isempty(reader_paths)) {
 		if (ellisys_server)
 			ellisys_enable(ellisys_server, ellisys_port);
 
-		control_reader(reader_path);
+		control_reader(reader_paths);
+		queue_destroy(reader_paths, NULL);
+
 		return EXIT_SUCCESS;
 	}
 
+	queue_destroy(reader_paths, NULL);
+
 	if (writer_path && !control_writer(writer_path)) {
 		printf("Failed to open '%s'\n", writer_path);
 		return EXIT_FAILURE;
diff --git a/monitor/packet.c b/monitor/packet.c
index b800a2d75..08397c40d 100644
--- a/monitor/packet.c
+++ b/monitor/packet.c
@@ -44,6 +44,7 @@
 #include "lib/hci_lib.h"
 
 #include "src/shared/util.h"
+#include "src/shared/queue.h"
 #include "src/shared/btsnoop.h"
 #include "display.h"
 #include "bt.h"
-- 
2.14.3