Re: [PATCH v7 02/10] lib: uuid: introduce uuid_str_to_le_bin function

Abdellatif El Khlifi
2022-11-14T10:12:04Z

On Fri, Nov 11, 2022 at 05:02:26PM +0000, Anders Dellien wrote:
> Hi Abdel,
>
> From: U-Boot <u-boot-bounces@lists.denx.de> on behalf of Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
> Date: Monday, 7 November 2022 at 19:22
> To: Abdellatif El Khlifi <Abdellatif.ElKhlifi@arm.com>
> Cc: Drew Reed <Drew.Reed@arm.com>, Achin Gupta <Achin.Gupta@arm.com>, ilias.apalodimas@linaro.org <ilias.apalodimas@linaro.org>, jens.wiklander@linaro.org <jens.wiklander@linaro.org>, nd <nd@arm.com>, sjg@chromium.org <sjg@chromium.org>, trini@konsulko.com <trini@konsulko.com>, u-boot@lists.denx.de <u-boot@lists.denx.de>, Vishnu Banavath <Vishnu.Banavath@arm.com>, Xueliang Zhong <Xueliang.Zhong@arm.com>
> Subject: [PATCH v7 02/10] lib: uuid: introduce uuid_str_to_le_bin function
> convert UUID string to little endian binary data
>
> Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Cc: Jens Wiklander <jens.wiklander@linaro.org>
>
> ---
>
> Changelog:
> ===============
>
> v7:
>
> * rename be_uuid_str_to_le_bin() to uuid_str_to_le_bin()
> * make uuid_str_to_le_bin() implementation similar to uuid_str_to_bin()
> by using same APIs
>
> v4:
>
> * rename ffa_uuid_str_to_bin to be_uuid_str_to_le_bin and put in
> a standalone commit (the current)
>
> v3:
>
> * introduce ffa_uuid_str_to_bin (provided by
> arm_ffa: introduce Arm FF-A low-level driver)
>
> include/uuid.h | 8 ++++++++
> lib/uuid.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 54 insertions(+)
>
> diff --git a/include/uuid.h b/include/uuid.h
> index 4a4883d3b5..293a8eb0a5 100644
> --- a/include/uuid.h
> +++ b/include/uuid.h
> @@ -2,6 +2,8 @@
> /*
> * Copyright (C) 2014 Samsung Electronics
> * Przemyslaw Marczak <p.marczak@samsung.com>
> + * (C) Copyright 2022 ARM Limited
> + * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
> */
> #ifndef __UUID_H__
> #define __UUID_H__
> @@ -44,4 +46,10 @@ int uuid_guid_get_bin(const char *guid_str, unsigned char *guid_bin);
> const char *uuid_guid_get_str(const unsigned char *guid_bin);
> void gen_rand_uuid(unsigned char *uuid_bin);
> void gen_rand_uuid_str(char *uuid_str, int str_format);
> +
> +/**
> + * uuid_str_to_le_bin - Converts a UUID string to little endian binary data
> + */
> +int uuid_str_to_le_bin(const char *uuid_str, unsigned char *uuid_bin);
> +
> #endif
> diff --git a/lib/uuid.c b/lib/uuid.c
> index 465e1ac38f..cde5ae2bb7 100644
> --- a/lib/uuid.c
> +++ b/lib/uuid.c
> @@ -1,6 +1,8 @@
> // SPDX-License-Identifier: GPL-2.0+
> /*
> * Copyright 2011 Calxeda, Inc.
> + * (C) Copyright 2022 ARM Limited
> + * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
> */
>
> #include <common.h>
> @@ -346,6 +348,50 @@ int uuid_str_to_bin(const char *uuid_str, unsigned char *uuid_bin,
> return 0;
> }
>
> +/**
> + * uuid_str_to_le_bin() - Convert string UUID to little endian binary data.
> + * @uuid_str: pointer to UUID string
> + * @uuid_bin: pointer to allocated array for little endian output [16B]
> + *
> + * UUID string is 36 characters (36 bytes):
> + *
> + * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
> + *
> + * where x is a hexadecimal character. Fields are separated by '-'s.
> + * When converting to a little endian binary UUID, the string fields are reversed.
> + *
> + * Return:
> + *
> + * uuid_bin filled with little endian UUID data
> + * On success 0 is returned. Otherwise, failure code.
> + */
> +int uuid_str_to_le_bin(const char *uuid_str, unsigned char *uuid_bin)
> +{
> + u16 tmp16;
> + u32 tmp32;
> + u64 tmp64;
> +
> + if (!uuid_str_valid(uuid_str) || !uuid_bin)
> + return -EINVAL;
> +
> + tmp32 = cpu_to_le32(hextoul(uuid_str, NULL));
> + memcpy(uuid_bin, &tmp32, 4);
> +
> + tmp16 = cpu_to_le16(hextoul(uuid_str + 9, NULL));
> + memcpy(uuid_bin + 4, &tmp16, 2);
> +
> + tmp16 = cpu_to_le16(hextoul(uuid_str + 14, NULL));
> + memcpy(uuid_bin + 6, &tmp16, 2);
> +
> + tmp16 = cpu_to_le16(hextoul(uuid_str + 19, NULL));
> + memcpy(uuid_bin + 8, &tmp16, 2);
> +
> + tmp64 = cpu_to_le64(hextoul(uuid_str + 24, NULL));
> + memcpy(uuid_bin + 10, (char *)&tmp64, 6);
>
> I think we might risk overflow here on platforms where “ulong” happens to be 32 bits.

Thanks Anders, a very valid point.

I will use simple_strtoull() in place of hextoul()

I'll make the change in v8.

>
> +
> + return 0;
> +}
> +
> /*
> * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
> *
> --
> 2.17.1