On Fri, Dec 30, 2022 at 6:51 PM Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> wrote: > > Le 30/12/2022 à 17:58, Jó Ágila Bitsch a écrit : > > There is a custom (non-USB IF) extension to the USB standard: > > > > https://wicg.github.io/webusb/ > > > > This specification is published under the W3C Community Contributor > > Agreement, which in particular allows to implement the specification > > without any royalties. > > > > The specification allows USB gadgets to announce an URL to landing > > page and describes a Javascript interface for websites to interact > > with the USB gadget, if the user allows it. It is currently > > supported by Chromium-based browsers, such as Chrome, Edge and > > Opera on all major operating systems including Linux. > > > > This patch adds optional support for Linux-based USB gadgets > > wishing to expose such a landing page. > > > > During device enumeration, a host recognizes that the announced > > USB version is at least 2.01, which means, that there are BOS > > descriptors available. The device than announces WebUSB support > > using a platform device capability. This includes a vendor code > > under which the landing page URL can be retrieved using a > > vendor-specific request. > > > > Usage is modeled after os_desc descriptors: > > echo 1 > webusb/use > > echo "https://www.kernel.org"; > webusb/landingPage > > > > lsusb will report the device with the following lines: > > Platform Device Capability: > > bLength 24 > > bDescriptorType 16 > > bDevCapabilityType 5 > > bReserved 0 > > PlatformCapabilityUUID {3408b638-09a9-47a0-8bfd-a0768815b665} > > WebUSB: > > bcdVersion 1.00 > > bVendorCode 0 > > iLandingPage 1 https://www.kernel.org > > > > Signed-off-by: Jó Ágila Bitsch <jgilab-Re5JQEeQqe8AvxtiuMwx3w@xxxxxxxxxxxxxxxx> > > Hi, > > a few nits below. > > CJ Thanks for your quick review. I answered inline and will post a new version with the points addressed. Best, Jó > > > --- > > Documentation/ABI/testing/configfs-usb-gadget | 13 ++ > > drivers/usb/gadget/composite.c | 102 +++++++++++-- > > drivers/usb/gadget/configfs.c | 139 ++++++++++++++++++ > > include/linux/usb/composite.h | 6 + > > include/uapi/linux/usb/ch9.h | 33 +++++ > > 5 files changed, 283 insertions(+), 10 deletions(-) > > > > diff --git a/Documentation/ABI/testing/configfs-usb-gadget b/Documentation/ABI/testing/configfs-usb-gadget > > index b7943aa7e997..8399e0f0ed1c 100644 > > --- a/Documentation/ABI/testing/configfs-usb-gadget > > +++ b/Documentation/ABI/testing/configfs-usb-gadget > > @@ -143,3 +143,16 @@ Description: > > qw_sign an identifier to be reported as "OS String" > > proper > > ============= =============================================== > > + > > +What: /config/usb-gadget/gadget/webusb > > +Date: Dec 2022 > > +KernelVersion: 6.2 > > +Description: > > + This group contains "WebUSB" extension handling attributes. > > + > > + ============= =============================================== > > + use flag turning "WebUSB" support on/off > > + bcdVersion bcd WebUSB specification version number > > + b_vendor_code one-byte value used for custom per-device > > + landing_page UTF-8 encoded URL of the device's landing page > > + ============= =============================================== > > diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c > > index 403563c06477..937695dc5366 100644 > > --- a/drivers/usb/gadget/composite.c > > +++ b/drivers/usb/gadget/composite.c > > @@ -14,6 +14,7 @@ > > #include <linux/device.h> > > #include <linux/utsname.h> > > #include <linux/bitfield.h> > > +#include <linux/uuid.h> > > > > #include <linux/usb/composite.h> > > #include <linux/usb/otg.h> > > @@ -713,14 +714,16 @@ static int bos_desc(struct usb_composite_dev *cdev) > > * A SuperSpeed device shall include the USB2.0 extension descriptor > > * and shall support LPM when operating in USB2.0 HS mode. > > */ > > - usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength); > > - bos->bNumDeviceCaps++; > > - le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE); > > - usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE; > > - usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY; > > - usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT; > > - usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT | > > - USB_BESL_SUPPORT | besl); > > + if (cdev->gadget->lpm_capable) { > > + usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength); > > + bos->bNumDeviceCaps++; > > + le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE); > > + usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE; > > + usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY; > > + usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT; > > + usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT | > > + USB_BESL_SUPPORT | besl); > > + } > > > > /* > > * The Superspeed USB Capability descriptor shall be implemented by all > > @@ -821,6 +824,41 @@ static int bos_desc(struct usb_composite_dev *cdev) > > } > > } > > > > + /* > > + * Following the specifaction at: > > + * https://wicg.github.io/webusb/#webusb-platform-capability-descriptor > > + */ > > + if (cdev->use_webusb) { > > + struct usb_webusb_cap_descriptor *webusb_cap; > > + /* > > + * little endian PlatformCapablityUUID for WebUSB: > > + * 3408b638-09a9-47a0-8bfd-a0768815b665 > > + */ > > +#define WEBUSB_UUID UUID_INIT(0x38b60834, 0xa909, 0xa047, \ > > + 0x8b, 0xfd, 0xa0, 0x76, 0x88, 0x15, 0xb6, 0x65) > > + uuid_t webusb_uuid = WEBUSB_UUID; > > + > > + webusb_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength); > > + bos->bNumDeviceCaps++; > > + > > + le16_add_cpu(&bos->wTotalLength, USB_DT_WEBUSB_SIZE); > > + webusb_cap->bLength = USB_DT_WEBUSB_SIZE; > > + webusb_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY; > > + webusb_cap->bDevCapabilityType = USB_PLAT_DEV_CAP_TYPE; > > + webusb_cap->bReserved = 0; > > + export_uuid(webusb_cap->UUID, &webusb_uuid); > > + if (cdev->bcd_webusb_version != 0) > > + webusb_cap->bcdVersion = cpu_to_le16(cdev->bcd_webusb_version); > > + else > > + webusb_cap->bcdVersion = cpu_to_le16(0x0100); > > + > > + webusb_cap->bVendorCode = cdev->b_webusb_vendor_code; > > + if (strnlen(cdev->landing_page, sizeof(cdev->landing_page)) > 0) > > + webusb_cap->iLandingPage = 1; > > + else > > + webusb_cap->iLandingPage = 0; > > + } > > + > > return le16_to_cpu(bos->wTotalLength); > > } > > > > @@ -1744,7 +1782,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) > > cdev->desc.bcdUSB = cpu_to_le16(0x0210); > > } > > } else { > > - if (gadget->lpm_capable) > > + if (gadget->lpm_capable || cdev->use_webusb) > > cdev->desc.bcdUSB = cpu_to_le16(0x0201); > > else > > cdev->desc.bcdUSB = cpu_to_le16(0x0200); > > @@ -1779,7 +1817,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) > > break; > > case USB_DT_BOS: > > if (gadget_is_superspeed(gadget) || > > - gadget->lpm_capable) { > > + gadget->lpm_capable || cdev->use_webusb) { > > value = bos_desc(cdev); > > value = min(w_length, (u16) value); > > } > > @@ -2013,6 +2051,50 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) > > goto check_value; > > } > > > > + /* > > + * webusb descriptor handling, following: > > + * https://wicg.github.io/webusb/#device-requests > > + */ > > + #define WEBUSB_GET_URL 2 > > + if (cdev->use_webusb && > > + (ctrl->bRequestType & USB_TYPE_VENDOR) && > > + ctrl->wIndex == WEBUSB_GET_URL && > > + ctrl->bRequest == cdev->b_webusb_vendor_code) { > > + /* > > + * specification of the url descriptor in WebUSB: > > + * https://wicg.github.io/webusb/#webusb-descriptors > > + */ > > + u8 *buf; > > + unsigned int schema_http; > > + unsigned int schema_https; > > + unsigned int landing_page_length; > > + > > + buf = cdev->req->buf; > > + #define WEBUSB_URL 3 > > + buf[1] = WEBUSB_URL; > > + > > + landing_page_length = strnlen(cdev->landing_page, 252); > > + schema_https = (strncmp("https://";, cdev->landing_page, 8) == 0); > > + schema_http = (strncmp("http://";, cdev->landing_page, 7) == 0); > > + if (schema_https) { > > + buf[2] = 0x01; > > + memcpy(buf+3, cdev->landing_page+8, landing_page_length-8); > > + buf[0] = landing_page_length - 8 + 3; > > + } else if (schema_http) { > > + buf[2] = 0x00; > > + memcpy(buf+3, cdev->landing_page+7, landing_page_length-7); > > + buf[0] = landing_page_length - 7 + 3; > > + } else { > > + buf[2] = 0xFF; > > + memcpy(buf+3, cdev->landing_page, landing_page_length); > > + buf[0] = landing_page_length + 3; > > + } > > + > > + value = buf[0]; > > + > > + goto check_value; > > + } > > + > > VDBG(cdev, > > "non-core control req%02x.%02x v%04x i%04x l%d\n", > > ctrl->bRequestType, ctrl->bRequest, > > diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c > > index 96121d1c8df4..0c1a78d9b5a0 100644 > > --- a/drivers/usb/gadget/configfs.c > > +++ b/drivers/usb/gadget/configfs.c > > @@ -39,6 +39,7 @@ struct gadget_info { > > struct config_group configs_group; > > struct config_group strings_group; > > struct config_group os_desc_group; > > + struct config_group webusb_group; > > > > struct mutex lock; > > struct usb_gadget_strings *gstrings[MAX_USB_STRING_LANGS + 1]; > > @@ -50,6 +51,11 @@ struct gadget_info { > > bool use_os_desc; > > char b_vendor_code; > > char qw_sign[OS_STRING_QW_SIGN_LEN]; > > + bool use_webusb; > > + u16 bcd_webusb_version; > > + u8 b_webusb_vendor_code; > > + char landing_page[255]; > > + > > spinlock_t spinlock; > > bool unbind; > > }; > > @@ -780,6 +786,125 @@ static void gadget_strings_attr_release(struct config_item *item) > > USB_CONFIG_STRING_RW_OPS(gadget_strings); > > USB_CONFIG_STRINGS_LANG(gadget_strings, gadget_info); > > > > +static inline struct gadget_info *webusb_item_to_gadget_info( > > + struct config_item *item) > > +{ > > + return container_of(to_config_group(item), > > + struct gadget_info, webusb_group); > > +} > > + > > +static ssize_t webusb_use_show(struct config_item *item, char *page) > > +{ > > + return sprintf(page, "%d\n", > > + webusb_item_to_gadget_info(item)->use_webusb); > > +} > > sysfs_emit()? > I will replace all sprintf calls with sysfs_emit calls in my next revision. Thanks for the pointer. > > + > > +static ssize_t webusb_use_store(struct config_item *item, const char *page, > > + size_t len) > > +{ > > + struct gadget_info *gi = webusb_item_to_gadget_info(item); > > + int ret; > > + bool use; > > + > > + mutex_lock(&gi->lock); > > + ret = kstrtobool(page, &use); > > + if (!ret) { > > + gi->use_webusb = use; > > + ret = len; > > + } > > + mutex_unlock(&gi->lock); > > + > > + return ret; > > +} > > + > > +static ssize_t webusb_bcdVersion_show(struct config_item *item, char *page) > > +{ > > + return snprintf(page, PAGE_SIZE, "0x%04x\n", > > + webusb_item_to_gadget_info(item)->bcd_webusb_version); > > +} > > sysfs_emit()? > > > + > > +static ssize_t webusb_bcdVersion_store(struct config_item *item, > > + const char *page, size_t len) > > +{ > > + struct gadget_info *gi = webusb_item_to_gadget_info(item); > > + u16 bcdVersion; > > Why camelCase here? Actually, I was unsure about that. I modelled my code on the os_desc implementation, which uses kebab_casing. However, all the other usb attributes (e.g. bcdUSB, bDeviceClass) use camelCase. So I thought it would be more consistent for users to have camelCase. That's why I stuck with camelCase for the attribute names (and the function names, so that I can use the default macros). > > > + int ret; > > no mutex_lock(&gi->lock); here? > Other _store functions have. Thanks for pointing that one out. I missed that one. > > + > > + ret = kstrtou16(page, 0, &bcdVersion); > > + if (ret) > > + return ret; > > + ret = is_valid_bcd(bcdVersion); > > + if (ret) > > + return ret; > > + > > + gi->bcd_webusb_version = bcdVersion; > > + return len; > > +} > > + > > +static ssize_t webusb_bVendorCode_show(struct config_item *item, char *page) > > +{ > > + return sprintf(page, "0x%02x\n", > > + webusb_item_to_gadget_info(item)->b_webusb_vendor_code); > > +} > > sysfs_emit()? > > > + > > +static ssize_t webusb_bVendorCode_store(struct config_item *item, > > + const char *page, size_t len) > > +{ > > + struct gadget_info *gi = webusb_item_to_gadget_info(item); > > + int ret; > > + u8 b_vendor_code; > > + > > + mutex_lock(&gi->lock); > > + ret = kstrtou8(page, 0, &b_vendor_code); > > + if (!ret) { > > + gi->b_webusb_vendor_code = b_vendor_code; > > + ret = len; > > + } > > + mutex_unlock(&gi->lock); > > + > > + return ret; > > +} > > + > > +static ssize_t webusb_landingPage_show(struct config_item *item, char *page) > > +{ > > + return snprintf(page, PAGE_SIZE, "%s\n", webusb_item_to_gadget_info(item)->landing_page); > > +} > > sysfs_emit()? > > > + > > +static ssize_t webusb_landingPage_store(struct config_item *item, const char *page, > > + size_t len) > > +{ > > + struct gadget_info *gi = webusb_item_to_gadget_info(item); > > + int l; > > + > > + l = min(len, sizeof(gi->landing_page)); > > + if (page[l - 1] == '\n') > > + --l; > > + > > + mutex_lock(&gi->lock); > > + memcpy(gi->landing_page, page, l); > > + mutex_unlock(&gi->lock); > > + > > + return len; > > +} > > + > > +CONFIGFS_ATTR(webusb_, use); > > +CONFIGFS_ATTR(webusb_, bVendorCode); > > +CONFIGFS_ATTR(webusb_, bcdVersion); > > +CONFIGFS_ATTR(webusb_, landingPage); > > + > > +static struct configfs_attribute *webusb_attrs[] = { > > + &webusb_attr_use, > > + &webusb_attr_bcdVersion, > > + &webusb_attr_bVendorCode, > > + &webusb_attr_landingPage, > > + NULL, > > +}; > > + > > +static struct config_item_type webusb_type = { > > + .ct_attrs = webusb_attrs, > > + .ct_owner = THIS_MODULE, > > +}; > > + > > static inline struct gadget_info *os_desc_item_to_gadget_info( > > struct config_item *item) > > { > > @@ -1341,6 +1466,16 @@ static int configfs_composite_bind(struct usb_gadget *gadget, > > gi->cdev.desc.iSerialNumber = s[USB_GADGET_SERIAL_IDX].id; > > } > > > > + if (gi->use_webusb) { > > + cdev->use_webusb = true; > > + cdev->bcd_webusb_version = gi->bcd_webusb_version; > > + cdev->b_webusb_vendor_code = gi->b_webusb_vendor_code; > > + memcpy(cdev->landing_page, gi->landing_page, > > + strnlen(gi->landing_page, > > + min(sizeof(cdev->landing_page), > > + sizeof(gi->landing_page)))); > > + } > > + > > if (gi->use_os_desc) { > > cdev->use_os_string = true; > > cdev->b_vendor_code = gi->b_vendor_code; > > @@ -1605,6 +1740,10 @@ static struct config_group *gadgets_make( > > &os_desc_type); > > configfs_add_default_group(&gi->os_desc_group, &gi->group); > > > > + config_group_init_type_name(&gi->webusb_group, "webusb", > > + &webusb_type); > > + configfs_add_default_group(&gi->webusb_group, &gi->group); > > + > > gi->composite.bind = configfs_do_nothing; > > gi->composite.unbind = configfs_do_nothing; > > gi->composite.suspend = NULL; > > diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h > > index 43ac3fa760db..44f90c37dda9 100644 > > --- a/include/linux/usb/composite.h > > +++ b/include/linux/usb/composite.h > > @@ -474,6 +474,12 @@ struct usb_composite_dev { > > struct usb_configuration *os_desc_config; > > unsigned int use_os_string:1; > > > > + /* WebUSB */ > > + u16 bcd_webusb_version; > > + u8 b_webusb_vendor_code; > > + char landing_page[255]; > > + unsigned int use_webusb:1; > > + > > /* private: */ > > /* internals */ > > unsigned int suspended:1; > > diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h > > index 31fcfa084e63..3a36550297bc 100644 > > --- a/include/uapi/linux/usb/ch9.h > > +++ b/include/uapi/linux/usb/ch9.h > > @@ -947,6 +947,39 @@ struct usb_ss_container_id_descriptor { > > > > #define USB_DT_USB_SS_CONTN_ID_SIZE 20 > > > > +/* > > + * Platform Device Capability descriptor: Defines platform specific device > > + * capabilities > > + */ > > +#define USB_PLAT_DEV_CAP_TYPE 5 > > +struct usb_plat_dev_cap_descriptor { > > + __u8 bLength; > > + __u8 bDescriptorType; > > + __u8 bDevCapabilityType; > > + __u8 bReserved; > > + __u8 UUID[16]; > > +} __attribute__((packed)); > > + > > +#define USB_DT_USB_PLAT_DEV_CAP_SIZE 20 > > + > > +/* > > + * WebUSB Platform Capability descriptor: A device announces support for the > > + * WebUSB command set by including the following Platform Descriptor in its > > + * Binary Object Store > > + * https://wicg.github.io/webusb/#webusb-platform-capability-descriptor > > + */ > > +struct usb_webusb_cap_descriptor { > > + __u8 bLength; > > + __u8 bDescriptorType; > > + __u8 bDevCapabilityType; > > + __u8 bReserved; > > + __u8 UUID[16]; > > + __u16 bcdVersion; > > + __u8 bVendorCode; > > + __u8 iLandingPage; > > +} __attribute__((packed)); > > +#define USB_DT_WEBUSB_SIZE (USB_DT_USB_PLAT_DEV_CAP_SIZE + 4) > > + > > /* > > * SuperSpeed Plus USB Capability descriptor: Defines the set of > > * SuperSpeed Plus USB specific device level capabilities >
