media/mtp/MtpDescriptors.cpp

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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 <android-base/logging.h>
#include <sys/types.h>

#include "MtpDescriptors.h"

namespace android {

const struct usb_interface_descriptor mtp_interface_desc = {
    .bLength = USB_DT_INTERFACE_SIZE,
    .bDescriptorType = USB_DT_INTERFACE,
    .bInterfaceNumber = 0,
    .bNumEndpoints = 3,
    .bInterfaceClass = USB_CLASS_STILL_IMAGE,
    .bInterfaceSubClass = 1,
    .bInterfaceProtocol = 1,
    .iInterface = 1,
};

const struct usb_interface_descriptor ptp_interface_desc = {
    .bLength = USB_DT_INTERFACE_SIZE,
    .bDescriptorType = USB_DT_INTERFACE,
    .bInterfaceNumber = 0,
    .bNumEndpoints = 3,
    .bInterfaceClass = USB_CLASS_STILL_IMAGE,
    .bInterfaceSubClass = 1,
    .bInterfaceProtocol = 1,
};

const struct usb_endpoint_descriptor_no_audio fs_sink = {
    .bLength = USB_DT_ENDPOINT_SIZE,
    .bDescriptorType = USB_DT_ENDPOINT,
    .bEndpointAddress = 1 | USB_DIR_IN,
    .bmAttributes = USB_ENDPOINT_XFER_BULK,
    .wMaxPacketSize = MAX_PACKET_SIZE_FS,
};

const struct usb_endpoint_descriptor_no_audio fs_source = {
    .bLength = USB_DT_ENDPOINT_SIZE,
    .bDescriptorType = USB_DT_ENDPOINT,
    .bEndpointAddress = 2 | USB_DIR_OUT,
    .bmAttributes = USB_ENDPOINT_XFER_BULK,
    .wMaxPacketSize = MAX_PACKET_SIZE_FS,
};

const struct usb_endpoint_descriptor_no_audio intr = {
    .bLength = USB_DT_ENDPOINT_SIZE,
    .bDescriptorType = USB_DT_ENDPOINT,
    .bEndpointAddress = 3 | USB_DIR_IN,
    .bmAttributes = USB_ENDPOINT_XFER_INT,
    .wMaxPacketSize = MAX_PACKET_SIZE_EV,
    .bInterval = 6,
};

const struct usb_endpoint_descriptor_no_audio hs_sink = {
    .bLength = USB_DT_ENDPOINT_SIZE,
    .bDescriptorType = USB_DT_ENDPOINT,
    .bEndpointAddress = 1 | USB_DIR_IN,
    .bmAttributes = USB_ENDPOINT_XFER_BULK,
    .wMaxPacketSize = MAX_PACKET_SIZE_HS,
};

const struct usb_endpoint_descriptor_no_audio hs_source = {
    .bLength = USB_DT_ENDPOINT_SIZE,
    .bDescriptorType = USB_DT_ENDPOINT,
    .bEndpointAddress = 2 | USB_DIR_OUT,
    .bmAttributes = USB_ENDPOINT_XFER_BULK,
    .wMaxPacketSize = MAX_PACKET_SIZE_HS,
};

const struct usb_endpoint_descriptor_no_audio ss_sink = {
    .bLength = USB_DT_ENDPOINT_SIZE,
    .bDescriptorType = USB_DT_ENDPOINT,
    .bEndpointAddress = 1 | USB_DIR_IN,
    .bmAttributes = USB_ENDPOINT_XFER_BULK,
    .wMaxPacketSize = MAX_PACKET_SIZE_SS,
};

const struct usb_endpoint_descriptor_no_audio ss_source = {
    .bLength = USB_DT_ENDPOINT_SIZE,
    .bDescriptorType = USB_DT_ENDPOINT,
    .bEndpointAddress = 2 | USB_DIR_OUT,
    .bmAttributes = USB_ENDPOINT_XFER_BULK,
    .wMaxPacketSize = MAX_PACKET_SIZE_SS,
};

const struct usb_ss_ep_comp_descriptor ss_sink_comp = {
    .bLength = sizeof(ss_sink_comp),
    .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
    .bMaxBurst = 6,
};

const struct usb_ss_ep_comp_descriptor ss_source_comp = {
    .bLength = sizeof(ss_source_comp),
    .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
    .bMaxBurst = 6,
};

const struct usb_ss_ep_comp_descriptor ss_intr_comp = {
    .bLength = sizeof(ss_intr_comp),
    .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
};

const struct func_desc mtp_fs_descriptors = {
    .intf = mtp_interface_desc,
    .sink = fs_sink,
    .source = fs_source,
    .intr = intr,
};

const struct func_desc mtp_hs_descriptors = {
    .intf = mtp_interface_desc,
    .sink = hs_sink,
    .source = hs_source,
    .intr = intr,
};

const struct ss_func_desc mtp_ss_descriptors = {
    .intf = mtp_interface_desc,
    .sink = ss_sink,
    .sink_comp = ss_sink_comp,
    .source = ss_source,
    .source_comp = ss_source_comp,
    .intr = intr,
    .intr_comp = ss_intr_comp,
};

const struct func_desc ptp_fs_descriptors = {
    .intf = ptp_interface_desc,
    .sink = fs_sink,
    .source = fs_source,
    .intr = intr,
};

const struct func_desc ptp_hs_descriptors = {
    .intf = ptp_interface_desc,
    .sink = hs_sink,
    .source = hs_source,
    .intr = intr,
};

const struct ss_func_desc ptp_ss_descriptors = {
    .intf = ptp_interface_desc,
    .sink = ss_sink,
    .sink_comp = ss_sink_comp,
    .source = ss_source,
    .source_comp = ss_source_comp,
    .intr = intr,
    .intr_comp = ss_intr_comp,
};

const struct functionfs_strings mtp_strings = {
    .header = {
        .magic = htole32(FUNCTIONFS_STRINGS_MAGIC),
        .length = htole32(sizeof(mtp_strings)),
        .str_count = htole32(1),
        .lang_count = htole32(1),
    },
    .lang0 = {
        .code = htole16(0x0409),
        .str1 = STR_INTERFACE,
    },
};

const struct usb_os_desc_header mtp_os_desc_header = {
    .interface = htole32(1),
    .dwLength = htole32(sizeof(usb_os_desc_header) + sizeof(usb_ext_compat_desc)),
    .bcdVersion = htole16(1),
    .wIndex = htole16(4),
    .bCount = htole16(1),
    .Reserved = htole16(0),
};

const struct usb_ext_compat_desc mtp_os_desc_compat = {
    .bFirstInterfaceNumber = 0,
    .Reserved1 = htole32(1),
    .CompatibleID = { 'M', 'T', 'P' },
    .SubCompatibleID = {0},
    .Reserved2 = {0},
};

const struct usb_ext_compat_desc ptp_os_desc_compat = {
    .bFirstInterfaceNumber = 0,
    .Reserved1 = htole32(1),
    .CompatibleID = { 'P', 'T', 'P' },
    .SubCompatibleID = {0},
    .Reserved2 = {0},
};

const struct desc_v2 mtp_desc_v2 = {
    .header = {
        .magic = htole32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
        .length = htole32(sizeof(struct desc_v2)),
        .flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC |
                 FUNCTIONFS_HAS_SS_DESC | FUNCTIONFS_HAS_MS_OS_DESC,
    },
    .fs_count = 4,
    .hs_count = 4,
    .ss_count = 7,
    .os_count = 1,
    .fs_descs = mtp_fs_descriptors,
    .hs_descs = mtp_hs_descriptors,
    .ss_descs = mtp_ss_descriptors,
    .os_header = mtp_os_desc_header,
    .os_desc = mtp_os_desc_compat,
};

const struct desc_v2 ptp_desc_v2 = {
    .header = {
        .magic = htole32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
        .length = htole32(sizeof(struct desc_v2)),
        .flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC |
                 FUNCTIONFS_HAS_SS_DESC | FUNCTIONFS_HAS_MS_OS_DESC,
    },
    .fs_count = 4,
    .hs_count = 4,
    .ss_count = 7,
    .os_count = 1,
    .fs_descs = ptp_fs_descriptors,
    .hs_descs = ptp_hs_descriptors,
    .ss_descs = ptp_ss_descriptors,
    .os_header = mtp_os_desc_header,
    .os_desc = ptp_os_desc_compat,
};

const struct desc_v1 mtp_desc_v1 = {
    .header = {
        .magic = htole32(FUNCTIONFS_DESCRIPTORS_MAGIC),
        .length = htole32(sizeof(struct desc_v1)),
        .fs_count = 4,
        .hs_count = 4,
    },
    .fs_descs = mtp_fs_descriptors,
    .hs_descs = mtp_hs_descriptors,
};

const struct desc_v1 ptp_desc_v1 = {
    .header = {
        .magic = htole32(FUNCTIONFS_DESCRIPTORS_MAGIC),
        .length = htole32(sizeof(struct desc_v1)),
        .fs_count = 4,
        .hs_count = 4,
    },
    .fs_descs = ptp_fs_descriptors,
    .hs_descs = ptp_hs_descriptors,
};

bool writeDescriptors(int fd, bool ptp) {
    ssize_t ret = TEMP_FAILURE_RETRY(write(fd,
                &(ptp ? ptp_desc_v2 : mtp_desc_v2), sizeof(desc_v2)));
    if (ret < 0) {
        PLOG(ERROR) << fd << "Switching to V1 descriptor format";
        ret = TEMP_FAILURE_RETRY(write(fd,
                    &(ptp ? ptp_desc_v1 : mtp_desc_v1), sizeof(desc_v1)));
        if (ret < 0) {
            PLOG(ERROR) << fd << "Writing descriptors failed";
            return false;
        }
    }
    ret = TEMP_FAILURE_RETRY(write(fd, &mtp_strings, sizeof(mtp_strings)));
    if (ret < 0) {
        PLOG(ERROR) << fd << "Writing strings failed";
        return false;
    }
    return true;
}

}; // namespace android