Should be usb_denylist, since "block devices" is ambiguous meaning if it is a list of data chunks (blocks) or if it blocks (deny). There is no question what a denylist is.
On Sun, Mar 17, 2024 at 4:07 AM Janne Grunau via B4 Relay <devnull+j.jannau....@kernel.org> wrote: > > From: Janne Grunau <j...@jannau.net> > > Add the environment variable "usb_blocklist" to prevent USB devices > listed in it from being used. This allows to ignore devices which > trigger bugs in u-boot's USB stack or are undesirable for other reasons. > Devices emulating keyboards are one example. U-boot currently supports > only one USB keyboard device. Most commonly, people run into this with > Yubikeys, so let's ignore those in the default environment. > > Based on previous USB keyboard specific patches for the same purpose. > > Link: > https://lore.kernel.org/u-boot/7ab604fb-0fec-4f5e-8708-7a3a7e2cb...@denx.de/ > Signed-off-by: Janne Grunau <j...@jannau.net> > --- > common/usb.c | 56 > +++++++++++++++++++++++++++++++++++++++++++++++ > doc/usage/environment.rst | 12 ++++++++++ > include/env_default.h | 11 ++++++++++ > 3 files changed, 79 insertions(+) > > diff --git a/common/usb.c b/common/usb.c > index 836506dcd9..73af5be066 100644 > --- a/common/usb.c > +++ b/common/usb.c > @@ -1084,6 +1084,57 @@ static int usb_prepare_device(struct usb_device *dev, > int addr, bool do_read, > return 0; > } > > +static int usb_blocklist_parse_error(const char *blocklist, size_t pos) > +{ > + printf("usb_blocklist parse error at char %zu in \"%s\"\n", pos, > + blocklist); > + return 0; > +} > + > +static int usb_device_is_blocked(u16 id_vendor, u16 id_product) > +{ > + ulong vid, pid; > + char *end; > + const char *block_str = env_get("usb_blocklist"); > + const char *cur = block_str; > + > + /* parse "usb_blocklist" strictly */ > + while (cur && cur[0] != '\0') { > + vid = simple_strtoul(cur, &end, 0); > + if (cur == end || end[0] != ':') > + return usb_blocklist_parse_error(block_str, > + cur - block_str); > + > + cur = end + 1; > + pid = simple_strtoul(cur, &end, 0); > + if (cur == end && end[0] != '*') > + return usb_blocklist_parse_error(block_str, > + cur - block_str); > + > + if (end[0] == '*') { > + /* use out of range idProduct as wildcard indication > */ > + pid = U16_MAX + 1; > + end++; > + } > + if (end[0] != ',' && end[0] != '\0') > + return usb_blocklist_parse_error(block_str, > + cur - block_str); > + > + if (id_vendor == vid && (pid > U16_MAX || id_product == pid)) > { > + printf("Ignoring USB device 0x%x:0x%x\n",id_vendor, > + id_product); > + debug("Ignoring USB device 0x%x:0x%x\n",id_vendor, > + id_product); > + return 1; > + } > + if (end[0] == '\0') > + break; > + cur = end + 1; > + } > + > + return 0; > +} > + > int usb_select_config(struct usb_device *dev) > { > unsigned char *tmpbuf = NULL; > @@ -1099,6 +1150,11 @@ int usb_select_config(struct usb_device *dev) > le16_to_cpus(&dev->descriptor.idProduct); > le16_to_cpus(&dev->descriptor.bcdDevice); > > + /* ignore devices from usb_blocklist */ > + if (usb_device_is_blocked(dev->descriptor.idVendor, > + dev->descriptor.idProduct)) > + return -ENODEV; > + > /* > * Kingston DT Ultimate 32GB USB 3.0 seems to be extremely sensitive > * about this first Get Descriptor request. If there are any other > diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst > index ebf75fa948..e42702adb2 100644 > --- a/doc/usage/environment.rst > +++ b/doc/usage/environment.rst > @@ -366,6 +366,18 @@ tftpwindowsize > This means the count of blocks we can receive before > sending ack to server. > > +usb_blocklist > + Block USB devices from being bound to an USB device driver. This can be > used > + to ignore devices which causes crashes in u-boot's USB stack or are > + undesirable for other reasons. > + The default environment blocks Yubico devices since they emulate USB > + keyboards. U-boot currently supports only a single USB keyboard device > and > + it is undesirable that a Yubikey is used as keyboard. > + Devices are matched by idVendor and idProduct. The variable contains a > comma > + separated list of idVendor:idProduct pairs as hexadecimal numbers joined > + by a colon. '*' functions as a wildcard for idProduct to block all > devices > + with the specified idVendor. > + > vlan > When set to a value < 4095 the traffic over > Ethernet is encapsulated/received over 802.1q > diff --git a/include/env_default.h b/include/env_default.h > index 2ca4a087d3..ba4c7516b4 100644 > --- a/include/env_default.h > +++ b/include/env_default.h > @@ -99,6 +99,17 @@ const char default_environment[] = { > #ifdef CONFIG_SYS_SOC > "soc=" CONFIG_SYS_SOC "\0" > #endif > +#ifdef CONFIG_USB_HOST > + "usb_blocklist=" > +#ifdef CONFIG_USB_KEYBOARD > + /* Ignore Yubico devices. Currently only a single USB keyboard device > is > + * supported and the emulated HID keyboard Yubikeys present is useless > + * as keyboard. > + */ > + "0x1050:*," > +#endif > + "\0" > +#endif > #ifdef CONFIG_ENV_IMPORT_FDT > "env_fdt_path=" CONFIG_ENV_FDT_PATH "\0" > #endif > > -- > 2.44.0 >
