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

[Szymon Janc <szymon.janc@codecoup.pl>]

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