[PATCH 0/5] Initial Android IPC

[PATCH 0/5] Initial Android IPC

[Szymon Janc]

Hi,

This adds initial code for Android IPC
- only connection establishment
- connecting ipc from daemon to HAL after adapter is initialized
- daemon track HAL lib lifetime and shutdown if socket is closed
- HAL library starts daemon (via android init) and wait for it to
  connect
- HAL library is *not* yet tracking lifetime of daemon

-- 
BR
Szymon Janc

Szymon Janc (5):
  android: Fix cutils/log.h stubs
  android: Define path for HAL communication socket
  android: Connect daemon to HAL library
  android: Make HAL library wait for daemon to connect on init
  android: Remove not needed property_get function form cutils stubs

 android/cutils/log.h        |  12 ++--
 android/cutils/properties.h |  27 ---------
 android/hal-bluetooth.c     | 127 ++++++++++++++++++++++++++++++++++--------
 android/hal-msg.h           |   2 +
 android/main.c              | 133 ++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 246 insertions(+), 55 deletions(-)

-- 
1.8.4.rc3

[PATCH 1/5] android: Fix cutils/log.h stubs

[Szymon Janc]

From: Szymon Janc <szymon.janc@tieto.com>

Provide dummy functions that will use macro parameters. This fix
build errors about set-but-not-used used local variables on linux.
---
 android/cutils/log.h | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/android/cutils/log.h b/android/cutils/log.h
index d87da72..7374add 100644
--- a/android/cutils/log.h
+++ b/android/cutils/log.h
@@ -17,11 +17,13 @@
 #ifndef _CUTILS_LOG_H
 #define _CUTILS_LOG_H
 
-#define ALOGV(...)
-#define ALOGD(...)
-#define ALOGI(...)
-#define ALOGW(...)
-#define ALOGE(...)
+static inline void dummy_printf(const char *fmt, ...) { }
+
+#define ALOGV(...) dummy_printf("", __VA_ARGS__)
+#define ALOGD(...) dummy_printf("", __VA_ARGS__)
+#define ALOGI(...) dummy_printf("", __VA_ARGS__)
+#define ALOGW(...) dummy_printf("", __VA_ARGS__)
+#define ALOGE(...) dummy_printf("", __VA_ARGS__)
 #define LOG_ALWAYS_FATAL(...)   do { ALOGE(__VA_ARGS__); exit(1); } while (0)
 
 #endif // _CUTILS_LOG_H
-- 
1.8.4.rc3

[PATCH 2/5] android: Define path for HAL communication socket

[Szymon Janc]

From: Szymon Janc <szymon.janc@tieto.com>

This socket will be used by android daemon and libhal to communitate.
---
 android/hal-msg.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/android/hal-msg.h b/android/hal-msg.h
index 4c5ca69..2da5e16 100644
--- a/android/hal-msg.h
+++ b/android/hal-msg.h
@@ -21,6 +21,8 @@
  *
  */
 
+#define BLUEZ_HAL_SK_PATH "bluez_hal_socket"
+
 struct hal_msg_hdr {
 	uint8_t service_id;
 	uint8_t opcode;
-- 
1.8.4.rc3

[PATCH 3/5] android: Connect daemon to HAL library

[Szymon Janc]

From: Szymon Janc <szymon.janc@tieto.com>

Connect to HAL when adapter initialization is finished. If any problem
with connection occurs or connected socket is closed by remote daemon
shutdowns.
---
 android/main.c | 133 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)

diff --git a/android/main.c b/android/main.c
index c3fb80e..5b71265 100644
--- a/android/main.c
+++ b/android/main.c
@@ -32,7 +32,10 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <string.h>
+#include <errno.h>
 #include <sys/signalfd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
 
 #include <glib.h>
 
@@ -44,6 +47,7 @@
 #include "src/shared/mgmt.h"
 
 #include "adapter.h"
+#include "hal-msg.h"
 
 #define SHUTDOWN_GRACE_SECONDS 10
 
@@ -55,8 +59,135 @@ static uint8_t mgmt_revision = 0;
 
 static uint16_t adapter_index = MGMT_INDEX_NONE;
 
+static GIOChannel *hal_cmd_io = NULL;
+static GIOChannel *hal_notif_io = NULL;
+
 static volatile sig_atomic_t __terminated = 0;
 
+static gboolean watch_cb(GIOChannel *io, GIOCondition cond,
+							gpointer user_data)
+{
+	info("HAL socket closed, terminating");
+	g_main_loop_quit(event_loop);
+
+	return FALSE;
+}
+
+static GIOChannel *create_io(void)
+{
+	int sk;
+	int err;
+	GIOChannel *io;
+
+	sk = socket(PF_LOCAL, SOCK_SEQPACKET, 0);
+	if (sk < 0) {
+		err = errno;
+		error("Failed to create socket: %d (%s)", err, strerror(err));
+		return NULL;
+	}
+
+	io = g_io_channel_unix_new(sk);
+
+	g_io_channel_set_close_on_unref(io, TRUE);
+	g_io_channel_set_flags(io, G_IO_FLAG_NONBLOCK, NULL);
+
+	return io;
+}
+
+static int connect_io(GIOChannel *io, GIOFunc connect_cb)
+{
+	int err;
+	struct sockaddr_un addr;
+	GIOCondition cond;
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+
+	/* Use abstract sockets so first byte needs to be \0 */
+	strcpy(addr.sun_path + 1, BLUEZ_HAL_SK_PATH);
+
+	err = connect(g_io_channel_unix_get_fd(io),
+				(struct sockaddr *) &addr, sizeof(addr));
+	if (err < 0) {
+		err = -errno;
+		error("Failed to connect HAL socket: %d (%s)", -err,
+							strerror(-err));
+		return err;
+	}
+
+	cond = G_IO_OUT | G_IO_ERR | G_IO_HUP | G_IO_NVAL;
+
+	g_io_add_watch(io, cond, connect_cb, NULL);
+
+	return 0;
+}
+
+static gboolean notif_connect_cb(GIOChannel *io, GIOCondition cond,
+							gpointer user_data)
+{
+	DBG("");
+
+	if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
+		g_main_loop_quit(event_loop);
+		return FALSE;
+	}
+
+	cond = G_IO_ERR | G_IO_HUP | G_IO_NVAL;
+
+	g_io_add_watch(io, cond, watch_cb, NULL);
+
+	info("Successfully connected to HAL");
+
+	/* TODO start handling commands */
+
+	return FALSE;
+}
+
+static void connect_notification_socket(void)
+{
+	DBG("");
+
+	hal_notif_io = create_io();
+
+	if (hal_notif_io && connect_io(hal_notif_io, notif_connect_cb) == 0)
+		return;
+
+	error("Cannot connect to HAL, terminating");
+	g_main_loop_quit(event_loop);
+}
+
+static gboolean cmd_connect_cb(GIOChannel *io, GIOCondition cond,
+							gpointer user_data)
+{
+	DBG("");
+
+	if (cond & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
+		g_main_loop_quit(event_loop);
+		return FALSE;
+	}
+
+	cond = G_IO_ERR | G_IO_HUP | G_IO_NVAL;
+
+	g_io_add_watch(io, cond, watch_cb, NULL);
+
+	connect_notification_socket();
+
+	return FALSE;
+}
+
+static void connect_cmd_socket(void)
+{
+	DBG("");
+
+	hal_cmd_io = create_io();
+
+	if (hal_cmd_io && connect_io(hal_cmd_io, cmd_connect_cb) == 0)
+		return;
+
+	error("Cannot connect to HAL, terminating");
+	g_main_loop_quit(event_loop);
+}
+
 static gboolean signal_handler(GIOChannel *channel, GIOCondition cond,
 							gpointer user_data)
 {
@@ -141,6 +272,8 @@ static void adapter_ready(struct bt_adapter *adapter, int err)
 	}
 
 	info("Adapter initialized");
+
+	connect_cmd_socket();
 }
 
 static void mgmt_index_added_event(uint16_t index, uint16_t length,
-- 
1.8.4.rc3

[PATCH 4/5] android: Make HAL library wait for daemon to connect on init

[Szymon Janc]

From: Szymon Janc <szymon.janc@tieto.com>

After starting up, daemon is responsible for connecting to HAL library.
If this doesn't happen before timeout occured init will fail.
---
 android/hal-bluetooth.c | 127 +++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 104 insertions(+), 23 deletions(-)

diff --git a/android/hal-bluetooth.c b/android/hal-bluetooth.c
index 2c6c2eb..c91bc98 100644
--- a/android/hal-bluetooth.c
+++ b/android/hal-bluetooth.c
@@ -19,6 +19,10 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdbool.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <poll.h>
 
 #include <hardware/bluetooth.h>
 #include <hardware/bt_sock.h>
@@ -31,41 +35,119 @@
 #include <cutils/log.h>
 
 #include "hal.h"
+#include "hal-msg.h"
 
 #define SERVICE_NAME "bluetoothd"
+#define CONNECT_TIMEOUT (5 * 1000)
 
 bt_callbacks_t *bt_hal_cbacks = NULL;
 
+static int cmd_sk = -1;
+static int notif_sk = -1;
+
 static bool interface_ready(void)
 {
 	return bt_hal_cbacks != NULL;
 }
 
-static bool start_bt_daemon(void)
+static int accept_connection(int sk)
 {
-	int tries = 40; /* wait 4 seconds for completion */
+	int err;
+	struct pollfd pfd;
+	int new_sk;
+
+	memset(&pfd, 0 , sizeof(pfd));
+	pfd.fd = sk;
+	pfd.events = POLLIN;
+
+	err = poll(&pfd, 1, CONNECT_TIMEOUT);
+	if (err < 0) {
+		err = errno;
+		ALOGE("Failed to poll: %d (%s)", err, strerror(err));
+		return -1;
+	}
 
-	ALOGD(__func__);
+	if (err == 0) {
+		ALOGE("bluetoothd connect timeout");
+		return -1;
+	}
+
+	new_sk = accept(sk, NULL, NULL);
+	if (new_sk < 0) {
+		err = errno;
+		ALOGE("Failed to accept socket: %d (%s)", err, strerror(err));
+		return -1;
+	}
+
+	return new_sk;
+}
+
+static bool start_daemon(void)
+{
+	struct sockaddr_un addr;
+	int sk;
+	int err;
+
+	sk = socket(AF_LOCAL, SOCK_SEQPACKET, 0);
+	if (sk < 0) {
+		err = errno;
+		ALOGE("Failed to create socket: %d (%s)", err,
+							strerror(err));
+		return false;
+	}
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+
+	/* Use abstract sockets so first byte needs to be \0 */
+	strcpy(addr.sun_path + 1, BLUEZ_HAL_SK_PATH);
+
+	if (bind(sk, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
+		err = errno;
+		ALOGE("Failed to bind socket: %d (%s)", err, strerror(err));
+		close(sk);
+		return false;
+	}
+
+	if (listen(sk, 2) < 0) {
+		err = errno;
+		ALOGE("Failed to listen on socket: %d (%s)", err,
+								strerror(err));
+		close(sk);
+		return false;
+	}
 
 	/* Start Android Bluetooth daemon service */
 	property_set("ctl.start", SERVICE_NAME);
 
-	while (tries-- > 0) {
-		char val[PROPERTY_VALUE_MAX];
-
-		if (property_get("init.svc." SERVICE_NAME, val, NULL)) {
-			if (!strcmp(val, "running")) {
-				ALOGI("Android BlueZ daemon started");
-				return true;
-			}
-		} else {
-			return false;
-		}
+	cmd_sk = accept_connection(sk);
+	if (cmd_sk < 0) {
+		close(sk);
+		return false;
+	}
 
-		usleep(100000);
+	notif_sk = accept_connection(sk);
+	if (notif_sk < 0) {
+		close(sk);
+		close(cmd_sk);
+		cmd_sk = -1;
+		return false;
 	}
 
-	return false;
+	ALOGI("bluetoothd connected");
+
+	close(sk);
+
+	return true;
+}
+
+static void stop_daemon(void)
+{
+	close(cmd_sk);
+	cmd_sk = -1;
+
+	close(notif_sk);
+	notif_sk = 1;
 }
 
 static int init(bt_callbacks_t *callbacks)
@@ -75,15 +157,12 @@ static int init(bt_callbacks_t *callbacks)
 	if (interface_ready())
 		return BT_STATUS_SUCCESS;
 
-	if (start_bt_daemon()) {
-		/* TODO: open channel */
+	if (!start_daemon())
+		return BT_STATUS_FAIL;
 
-		bt_hal_cbacks = callbacks;
+	bt_hal_cbacks = callbacks;
 
-		return BT_STATUS_SUCCESS;
-	}
-
-	return BT_STATUS_UNSUPPORTED;
+	return BT_STATUS_SUCCESS;
 }
 
 static int enable(void)
@@ -110,6 +189,8 @@ static void cleanup(void)
 	if (!interface_ready())
 		return;
 
+	stop_daemon();
+
 	bt_hal_cbacks = NULL;
 }
 
-- 
1.8.4.rc3

[PATCH 5/5] android: Remove not needed property_get function form cutils stubs

[Szymon Janc]

From: Szymon Janc <szymon.janc@tieto.com>

This is no longer used as daemon indicates its presence by connecting
socket.
---
 android/cutils/properties.h | 27 ---------------------------
 1 file changed, 27 deletions(-)

diff --git a/android/cutils/properties.h b/android/cutils/properties.h
index 44a712c..f318b01 100644
--- a/android/cutils/properties.h
+++ b/android/cutils/properties.h
@@ -24,33 +24,6 @@
 extern "C" {
 #endif
 
-#define PROPERTY_KEY_MAX   32
-#define PROPERTY_VALUE_MAX  92
-
-/* property_get: returns the length of the value which will never be
-** greater than PROPERTY_VALUE_MAX - 1 and will always be zero terminated.
-** (the length does not include the terminating zero).
-**
-** If the property read fails or returns an empty value, the default
-** value is used (if nonnull).
-*/
-static inline int property_get(const char *key, char *value,
-						const char *default_value)
-{
-	const char *env;
-
-	env = getenv(key);
-	if (!env)
-		env = default_value;
-
-	if (!value || !env)
-		return 0;
-
-	strncpy(value, env, PROPERTY_VALUE_MAX);
-
-	return strlen(value);
-}
-
 /* property_set: returns 0 on success, < 0 on failure
 */
 static inline int property_set(const char *key, const char *value)
-- 
1.8.4.rc3

Re: [PATCH 0/5] Initial Android IPC

[Szymon Janc]

> This adds initial code for Android IPC
> - only connection establishment
> - connecting ipc from daemon to HAL after adapter is initialized
> - daemon track HAL lib lifetime and shutdown if socket is closed
> - HAL library starts daemon (via android init) and wait for it to
>   connect
> - HAL library is *not* yet tracking lifetime of daemon

One more note I forgot to mention: this is not yet runtime tested on Android.
(build was verified though)

-- 
Szymon K. Janc
szymon.janc@gmail.com