Use systemd functionfs socket activation

This includes creating binary files with descriptors and strings at
compile time and systemd configuration of ffs socket.

Change-Id: Ib38dc151e5e5d047ddb873661505ca13ddfc3306
Signed-off-by: Paweł Szewczyk <p.szewczyk@samsung.com>

9 files changed, 262 insertions, 133 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f2ce402..2b384e2 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,7 +13,7 @@ AUX_SOURCE_DIRECTORY(${CMAKE_SOURCE_DIR}/src/util SRCS)
 
 INCLUDE(FindPkgConfig)
 pkg_check_modules(pkgs REQUIRED glib-2.0 capi-content-media-content
-	capi-media-metadata-extractor vconf dlog tapi capi-system-info storage libsystemd-daemon)
+	capi-media-metadata-extractor vconf dlog tapi capi-system-info storage libsystemd-daemon libsystemd)
 
 FOREACH(flag ${pkgs_CFLAGS})
 	SET(EXTRA_CFLAGS "${EXTRA_CFLAGS} ${flag}")
@@ -30,3 +30,13 @@ TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${pkgs_LDFLAGS} pthread rt gcrypt)
 
 INSTALL(TARGETS ${PROJECT_NAME} DESTINATION bin)
 INSTALL(FILES mtp-responder.conf DESTINATION /opt/var/lib/misc)
+
+ADD_EXECUTABLE(extract_descs_strs ${CMAKE_SOURCE_DIR}/src/extract_descs/mtp_extract_descs_strs.c
+	${CMAKE_SOURCE_DIR}/src/transport/mtp_descs_strings.c)
+ADD_CUSTOM_COMMAND(OUTPUT descs strs
+	COMMAND ./extract_descs_strs
+	DEPENDS extract_descs_strs)
+ADD_CUSTOM_TARGET(descs_strs ALL DEPENDS descs strs)
+
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/descs DESTINATION /etc/mtp-responder)
+INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/strs DESTINATION /etc/mtp-responder)
diff --git a/include/transport/mtp_descs_strings.h b/include/transport/mtp_descs_strings.h
new file mode 100644
index 0000000..37747ba
--- /dev/null
+++ b/include/transport/mtp_descs_strings.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2012, 2013, 2018 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/functionfs.h>
+#include <endian.h>
+
+#ifndef FUNCTIONFS_DESCRIPTORS_MAGIC_V2
+#define FUNCTIONFS_DESCRIPTORS_MAGIC_V2 3
+enum functionfs_flags {
+        FUNCTIONFS_HAS_FS_DESC = 1,
+        FUNCTIONFS_HAS_HS_DESC = 2,
+        FUNCTIONFS_HAS_SS_DESC = 4,
+        FUNCTIONFS_HAS_MS_OS_DESC = 8,
+};
+#endif
+
+#define cpu_to_le16(x)  htole16(x)
+#define cpu_to_le32(x)  htole32(x)
+#define le32_to_cpu(x)  le32toh(x)
+#define le16_to_cpu(x)  le16toh(x)
+
+extern struct mtp_usb_descs{
+	struct {
+		__le32 magic;
+		__le32 length;
+		__le32 flags;
+		__le32 fs_count;
+		__le32 hs_count;
+		// __le32 os_count;
+	} header;
+	struct {
+		struct usb_interface_descriptor intf;
+		struct usb_endpoint_descriptor_no_audio bulk_in;
+		struct usb_endpoint_descriptor_no_audio bulk_out;
+		struct usb_endpoint_descriptor_no_audio int_in;
+	} __attribute__((packed)) fs_descs, hs_descs;
+	// struct {} __attribute__((packed)) os_descs;
+} __attribute__((packed)) descriptors;
+
+#define STR_INTERFACE "Samsung MTP"
+
+extern struct mtp_usb_strs {
+	struct usb_functionfs_strings_head header;
+	struct {
+		__le16 code;
+		const char str1[sizeof(STR_INTERFACE)];
+	} __attribute__((packed)) lang0;
+} __attribute__((packed)) strings;
diff --git a/mtp-responder.service b/mtp-responder.service
index 24acdfe..69433c4 100755
--- a/mtp-responder.service
+++ b/mtp-responder.service
@@ -9,3 +9,5 @@ Type=simple
 ExecStart=/usr/bin/mtp-responder
 KillMode=process
 SmackProcessLabel=System
+USBFunctionDescriptors=/etc/mtp-responder/descs
+USBFunctionStrings=/etc/mtp-responder/strs
diff --git a/mtp-responder.socket b/mtp-responder.socket
new file mode 100755
index 0000000..0abae50
--- /dev/null
+++ b/mtp-responder.socket
@@ -0,0 +1,6 @@
+[Unit]
+Description=MTP responder functionfs socket
+
+[Socket]
+ListenUSBFunction=/dev/usb-funcs/mtp
+Service=mtp-responder.service
diff --git a/packaging/mtp-responder.spec b/packaging/mtp-responder.spec
index b1f1861..93187ae 100755
--- a/packaging/mtp-responder.spec
+++ b/packaging/mtp-responder.spec
@@ -22,6 +22,7 @@ BuildRequires: pkgconfig(capi-media-metadata-extractor)
 BuildRequires: pkgconfig(capi-system-info)
 Buildrequires: pkgconfig(storage)
 BuildRequires: pkgconfig(libsystemd-daemon)
+BuildRequires: pkgconfig(libsystemd)
 Requires(post): /usr/bin/vconftool
 
 %define upgrade_script_path /usr/share/upgrade/scripts
@@ -53,6 +54,7 @@ mkdir -p %{buildroot}%{upgrade_script_path}
 cp -f scripts/500.%{name}-upgrade.sh %{buildroot}%{upgrade_script_path}
 
 install -D -m 0644 mtp-responder.service %{buildroot}/%{_unitdir}/mtp-responder.service
+install -D -m 0644 mtp-responder.socket %{buildroot}/%{_unitdir}/mtp-responder.socket
 
 %post
 mkdir -p %{_sysconfdir}/systemd/default-extra-dependencies/ignore-units.d/
@@ -64,6 +66,9 @@ ln -sf %{_unitdir}/mtp-responder.service %{_sysconfdir}/systemd/default-extra-de
 %defattr(-,root,root,-)
 %{_bindir}/mtp-responder
 %{_unitdir}/mtp-responder.service
+%{_unitdir}/mtp-responder.socket
 %{_prefix}/lib/udev/rules.d/99-mtp-responder.rules
 /opt/var/lib/misc/mtp-responder.conf
 %{upgrade_script_path}/500.%{name}-upgrade.sh
+/etc/mtp-responder/descs
+/etc/mtp-responder/strs
diff --git a/src/extract_descs/mtp_extract_descs_strs.c b/src/extract_descs/mtp_extract_descs_strs.c
new file mode 100644
index 0000000..947c4e2
--- /dev/null
+++ b/src/extract_descs/mtp_extract_descs_strs.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2012, 2013, 2018 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include "mtp_descs_strings.h"
+
+static int write_blob(const char *filename, const void *blob, size_t size)
+{
+	int ret;
+	FILE *fp;
+
+	fp = fopen(filename, "w");
+	if (!fp) {
+		fprintf(stderr, "Could not open %s: %m\n", filename);
+		return -errno;
+	}
+
+	ret = fwrite(blob, size, 1, fp);
+	if (ret < 0) {
+		fprintf(stderr, "Could not write to %s\n");
+		goto out;
+	}
+
+	ret = 0;
+
+out:
+	fclose(fp);
+	return ret;
+}
+
+int main()
+{
+	int ret;
+
+	ret = write_blob("descs", &descriptors, sizeof(descriptors));
+	if (ret < 0)
+		return ret;
+
+	ret = write_blob("strs", &strings, sizeof(strings));
+	return ret;
+}
diff --git a/src/transport/mtp_descs_strings.c b/src/transport/mtp_descs_strings.c
new file mode 100644
index 0000000..f5d90e2
--- /dev/null
+++ b/src/transport/mtp_descs_strings.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2012, 2013, 2018 Samsung Electronics Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mtp_descs_strings.h"
+
+struct mtp_usb_descs descriptors = {
+	.header = {
+		.magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
+		.length = cpu_to_le32(sizeof(descriptors)),
+		.flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC, // | FUNCTIONFS_HAS_MS_OS_DESC,
+		.fs_count = 4,
+		.hs_count = 4,
+		// .os_count = 0;
+	},
+	.fs_descs = {
+		// drivers/usb/gadget/f_mtp_slp.c:207
+		.intf = {
+			.bLength = sizeof(descriptors.fs_descs.intf),
+			.bDescriptorType = USB_DT_INTERFACE,
+			.bNumEndpoints = 3,
+			.bInterfaceClass = USB_CLASS_STILL_IMAGE,
+			.bInterfaceSubClass = 1,
+			.bInterfaceProtocol = 1,
+			.iInterface = 1,
+		},
+		.bulk_in = {
+			.bLength = USB_DT_ENDPOINT_SIZE,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 1 | USB_DIR_IN,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			.wMaxPacketSize = __constant_cpu_to_le16(64),
+		},
+		.bulk_out = {
+			.bLength = USB_DT_ENDPOINT_SIZE,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 2 | USB_DIR_OUT,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			.wMaxPacketSize = __constant_cpu_to_le16(64),
+		},
+		.int_in = {
+			.bLength = USB_DT_ENDPOINT_SIZE,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 3 | USB_DIR_IN,
+			.bmAttributes = USB_ENDPOINT_XFER_INT,
+			.wMaxPacketSize = __constant_cpu_to_le16(64),
+			.bInterval = 6,
+		},
+	},
+	.hs_descs = {
+		.intf = {
+			.bLength = sizeof(descriptors.fs_descs.intf),
+			.bDescriptorType = USB_DT_INTERFACE,
+			.bNumEndpoints = 3,
+			.bInterfaceClass = USB_CLASS_STILL_IMAGE,
+			.bInterfaceSubClass = 1,
+			.bInterfaceProtocol = 1,
+			.iInterface = 1,
+		},
+		.bulk_in = {
+			.bLength = USB_DT_ENDPOINT_SIZE,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 1 | USB_DIR_IN,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			.wMaxPacketSize = __constant_cpu_to_le16(512),
+		},
+		.bulk_out = {
+			.bLength = USB_DT_ENDPOINT_SIZE,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 2 | USB_DIR_OUT,
+			.bmAttributes = USB_ENDPOINT_XFER_BULK,
+			.wMaxPacketSize = __constant_cpu_to_le16(512),
+		},
+		.int_in = {
+			.bLength = USB_DT_ENDPOINT_SIZE,
+			.bDescriptorType = USB_DT_ENDPOINT,
+			.bEndpointAddress = 3 | USB_DIR_IN,
+			.bmAttributes = USB_ENDPOINT_XFER_INT,
+			.wMaxPacketSize = __constant_cpu_to_le16(64),
+			.bInterval = 6,
+		},
+	},
+};
+
+struct mtp_usb_strs strings = {
+	.header = {
+		.magic = cpu_to_le32(FUNCTIONFS_STRINGS_MAGIC),
+		.length = cpu_to_le32(sizeof(strings)),
+		.str_count = cpu_to_le32(1),
+		.lang_count = cpu_to_le32(1),
+	},
+	.lang0 = {
+		cpu_to_le16(0x0409), /* en-us */
+		STR_INTERFACE,
+	},
+};
diff --git a/src/transport/mtp_usb_driver.c b/src/transport/mtp_usb_driver.c
index 5576c55..6fde025 100644
--- a/src/transport/mtp_usb_driver.c
+++ b/src/transport/mtp_usb_driver.c
@@ -15,6 +15,7 @@
  */
 
 #include <unistd.h>
+#include <systemd/sd-daemon.h>
 #include "mtp_usb_driver.h"
 
 static const mtp_usb_driver_t *usb_driver;
@@ -26,7 +27,7 @@ mtp_bool _transport_init_usb_device(void)
 {
 	if (access(MTP_DRIVER_PATH, F_OK) == 0) {
 		usb_driver = &mtp_usb_driver_slp;
-	} else if (access(MTP_EP0_PATH, F_OK) == 0) {
+	} else if (access(MTP_EP0_PATH, F_OK) == 0 || sd_listen_fds(0) >= 4) {
 		usb_driver = &mtp_usb_driver_ffs;
 	} else {
 		ERR("No suport for USB gadgets in kernel");
diff --git a/src/transport/mtp_usb_driver_ffs.c b/src/transport/mtp_usb_driver_ffs.c
index e972756..091daa8 100755
--- a/src/transport/mtp_usb_driver_ffs.c
+++ b/src/transport/mtp_usb_driver_ffs.c
@@ -25,6 +25,7 @@
 #include <glib.h>
 #include "mtp_usb_driver.h"
 #include "mtp_device.h"
+#include "mtp_descs_strings.h"
 #include "ptp_datacodes.h"
 #include "mtp_support.h"
 #include "ptp_container.h"
@@ -33,8 +34,7 @@
 #include "mtp_transport.h"
 #include "mtp_event_handler.h"
 #include <sys/prctl.h>
-#include <linux/usb/ch9.h>
-#include <linux/usb/functionfs.h>
+#include <systemd/sd-daemon.h>
 
 /*
  * GLOBAL AND EXTERN VARIABLES
@@ -44,15 +44,6 @@ extern mtp_config_t g_conf;
 /*
  * STATIC VARIABLES AND FUNCTIONS
  */
-#ifndef FUNCTIONFS_DESCRIPTORS_MAGIC_V2
-#define FUNCTIONFS_DESCRIPTORS_MAGIC_V2 3
-enum functionfs_flags {
-	FUNCTIONFS_HAS_FS_DESC = 1,
-	FUNCTIONFS_HAS_HS_DESC = 2,
-	FUNCTIONFS_HAS_SS_DESC = 4,
-	FUNCTIONFS_HAS_MS_OS_DESC = 8,
-};
-#endif
 
 /*PIMA15740-2000 spec*/
 #define USB_PTPREQUEST_CANCELIO   0x64    /* Cancel request */
@@ -62,126 +53,6 @@ enum functionfs_flags {
 #define USB_PTPREQUEST_CANCELIO_SIZE 6
 #define USB_PTPREQUEST_GETSTATUS_SIZE 12
 
-#define cpu_to_le16(x)  htole16(x)
-#define cpu_to_le32(x)  htole32(x)
-#define le32_to_cpu(x)  le32toh(x)
-#define le16_to_cpu(x)  le16toh(x)
-
-static const struct {
-	struct {
-		__le32 magic;
-		__le32 length;
-		__le32 flags;
-		__le32 fs_count;
-		__le32 hs_count;
-		// __le32 os_count;
-	} header;
-	struct {
-		struct usb_interface_descriptor intf;
-		struct usb_endpoint_descriptor_no_audio bulk_in;
-		struct usb_endpoint_descriptor_no_audio bulk_out;
-		struct usb_endpoint_descriptor_no_audio int_in;
-	} __attribute__((packed)) fs_descs, hs_descs;
-	// struct {} __attribute__((packed)) os_descs;
-} __attribute__((packed)) descriptors = {
-	.header = {
-		.magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
-		.length = cpu_to_le32(sizeof(descriptors)),
-		.flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC, // | FUNCTIONFS_HAS_MS_OS_DESC,
-		.fs_count = 4,
-		.hs_count = 4,
-		// .os_count = 0;
-	},
-	.fs_descs = {
-		// drivers/usb/gadget/f_mtp_slp.c:207
-		.intf = {
-			.bLength = sizeof(descriptors.fs_descs.intf),
-			.bDescriptorType = USB_DT_INTERFACE,
-			.bNumEndpoints = 3,
-			.bInterfaceClass = USB_CLASS_STILL_IMAGE,
-			.bInterfaceSubClass = 1,
-			.bInterfaceProtocol = 1,
-			.iInterface = 1,
-		},
-		.bulk_in = {
-			.bLength = USB_DT_ENDPOINT_SIZE,
-			.bDescriptorType = USB_DT_ENDPOINT,
-			.bEndpointAddress = 1 | USB_DIR_IN,
-			.bmAttributes = USB_ENDPOINT_XFER_BULK,
-			.wMaxPacketSize = __constant_cpu_to_le16(64),
-		},
-		.bulk_out = {
-			.bLength = USB_DT_ENDPOINT_SIZE,
-			.bDescriptorType = USB_DT_ENDPOINT,
-			.bEndpointAddress = 2 | USB_DIR_OUT,
-			.bmAttributes = USB_ENDPOINT_XFER_BULK,
-			.wMaxPacketSize = __constant_cpu_to_le16(64),
-		},
-		.int_in = {
-			.bLength = USB_DT_ENDPOINT_SIZE,
-			.bDescriptorType = USB_DT_ENDPOINT,
-			.bEndpointAddress = 3 | USB_DIR_IN,
-			.bmAttributes = USB_ENDPOINT_XFER_INT,
-			.wMaxPacketSize = __constant_cpu_to_le16(64),
-			.bInterval = 6,
-		},
-	},
-	.hs_descs = {
-		.intf = {
-			.bLength = sizeof(descriptors.fs_descs.intf),
-			.bDescriptorType = USB_DT_INTERFACE,
-			.bNumEndpoints = 3,
-			.bInterfaceClass = USB_CLASS_STILL_IMAGE,
-			.bInterfaceSubClass = 1,
-			.bInterfaceProtocol = 1,
-			.iInterface = 1,
-		},
-		.bulk_in = {
-			.bLength = USB_DT_ENDPOINT_SIZE,
-			.bDescriptorType = USB_DT_ENDPOINT,
-			.bEndpointAddress = 1 | USB_DIR_IN,
-			.bmAttributes = USB_ENDPOINT_XFER_BULK,
-			.wMaxPacketSize = __constant_cpu_to_le16(512),
-		},
-		.bulk_out = {
-			.bLength = USB_DT_ENDPOINT_SIZE,
-			.bDescriptorType = USB_DT_ENDPOINT,
-			.bEndpointAddress = 2 | USB_DIR_OUT,
-			.bmAttributes = USB_ENDPOINT_XFER_BULK,
-			.wMaxPacketSize = __constant_cpu_to_le16(512),
-		},
-		.int_in = {
-			.bLength = USB_DT_ENDPOINT_SIZE,
-			.bDescriptorType = USB_DT_ENDPOINT,
-			.bEndpointAddress = 3 | USB_DIR_IN,
-			.bmAttributes = USB_ENDPOINT_XFER_INT,
-			.wMaxPacketSize = __constant_cpu_to_le16(64),
-			.bInterval = 6,
-		},
-	},
-};
-
-#define STR_INTERFACE "Samsung MTP"
-
-static const struct {
-	struct usb_functionfs_strings_head header;
-	struct {
-		__le16 code;
-		const char str1[sizeof(STR_INTERFACE)];
-	} __attribute__((packed)) lang0;
-} __attribute__((packed)) strings = {
-	.header = {
-		.magic = cpu_to_le32(FUNCTIONFS_STRINGS_MAGIC),
-		.length = cpu_to_le32(sizeof(strings)),
-		.str_count = cpu_to_le32(1),
-		.lang_count = cpu_to_le32(1),
-	},
-	.lang0 = {
-		cpu_to_le16(0x0409), /* en-us */
-		STR_INTERFACE,
-	},
-};
-
 static mtp_int32 g_usb_ep0 = -1;       /* read (g_usb_ep0, ...) */
 static mtp_int32 g_usb_ep_in = -1;     /* write (g_usb_ep_in, ...) */
 static mtp_int32 g_usb_ep_out = -1;    /* read (g_usb_ep_out, ...) */
@@ -203,6 +74,15 @@ static mtp_bool __io_init()
 {
 	int ret;
 
+	if (sd_listen_fds(0) >= 4) {
+		g_usb_ep0 = SD_LISTEN_FDS_START;
+		g_usb_ep_in = SD_LISTEN_FDS_START + 1;
+		g_usb_ep_out = SD_LISTEN_FDS_START + 2;
+		g_usb_ep_status = SD_LISTEN_FDS_START + 3;
+
+		return TRUE;
+	}
+
 	g_usb_ep0 = open(MTP_EP0_PATH, O_RDWR);
 	if (g_usb_ep0 < 0)
 		goto out;