[v4,1/2] Import CBOR library

Message ID	20231009212053.2007-2-graf@amazon.com (mailing list archive)
State	Not Applicable
Delegated to:	Herbert Xu
Headers	show Return-Path: <linux-crypto-owner@vger.kernel.org> From: Alexander Graf <graf@amazon.com> To: <linux-kernel@vger.kernel.org> CC: <linux-crypto@vger.kernel.org>, Arnd Bergmann <arnd@arndb.de>, "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>, Herbert Xu <herbert@gondor.apana.org.au>, Olivia Mackall <olivia@selenic.com>, "Petre Eftime" <petre.eftime@gmail.com>, Erdem Meydanlli <meydanli@amazon.nl>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, David Woodhouse <dwmw@amazon.co.uk>, "Michael S . Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>, Xuan Zhuo <xuanzhuo@linux.alibaba.com>, Kyunghwan Kwon <k@mononn.com> Subject: [PATCH v4 1/2] Import CBOR library Date: Mon, 9 Oct 2023 21:20:52 +0000 Message-ID: <20231009212053.2007-2-graf@amazon.com> In-Reply-To: <20231009212053.2007-1-graf@amazon.com> References: <20231009212053.2007-1-graf@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Precedence: bulk
Series	Add Nitro Secure Module support \| expand [v4,0/2] Add Nitro Secure Module support [v4,1/2] Import CBOR library [v4,2/2] misc: Add Nitro Secure Module driver

diff --git a/MAINTAINERS b/MAINTAINERS index 6c4cce45a09d..5c23081ede95 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4661,6 +4661,14 @@ S: Odd Fixes F: Documentation/devicetree/bindings/arm/cavium-thunder2.txt F: arch/arm64/boot/dts/cavium/thunder2-99xx* +CBOR LIBRARY +M: Alexander Graf <graf@amazon.com> +L: linux-kernel@vger.kernel.org +L: The AWS Nitro Enclaves Team <aws-nitro-enclaves-devel@amazon.com> +S: Supported +F: include/linux/cbor/ +F: lib/cbor/ + CBS/ETF/TAPRIO QDISCS M: Vinicius Costa Gomes <vinicius.gomes@intel.com> L: netdev@vger.kernel.org diff --git a/include/linux/cbor/base.h b/include/linux/cbor/base.h new file mode 100644 index 000000000000..db15fb834b4f --- /dev/null +++ b/include/linux/cbor/base.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: MIT */ +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#ifndef CBOR_BASE_H +#define CBOR_BASE_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#include <linux/stddef.h> +#include <linux/types.h> + +#if !defined(CBOR_RECURSION_MAX_LEVEL) +#define CBOR_RECURSION_MAX_LEVEL 8 +#endif + +#define CBOR_INDEFINITE_VALUE (-1) +#define CBOR_RESERVED_VALUE (-2) + +#define CBOR_ADDITIONAL_INFO_MASK 0x1fu /* the low-order 5 bits */ +#define get_cbor_major_type(data_item) ((data_item) >> 5) +#define get_cbor_additional_info(major_type) \ + ((major_type) & CBOR_ADDITIONAL_INFO_MASK) + +typedef enum { + CBOR_SUCCESS, /**< well-formed */ + CBOR_ILLEGAL, /**< not well-formed */ + CBOR_INVALID, /**< well-formed but invalid */ + CBOR_OVERRUN, /**< more items than given buffer space */ + CBOR_BREAK, + CBOR_EXCESSIVE, /**< recursion more than @ref CBOR_RECURSION_MAX_LEVEL */ +} cbor_error_t; + +typedef enum { + CBOR_ITEM_UNKNOWN, + CBOR_ITEM_INTEGER, /**< unsigned integer and negative integer */ + CBOR_ITEM_STRING, /**< byte string and text string */ + CBOR_ITEM_ARRAY, + CBOR_ITEM_MAP, + CBOR_ITEM_FLOAT, + CBOR_ITEM_SIMPLE_VALUE, +} cbor_item_data_t; + +typedef struct { + cbor_item_data_t type; + size_t offset; + size_t size; /**< either of the length of value in bytes or the number + of items in case of container type */ +} cbor_item_t; + +typedef struct { + uint8_t const *msg; + size_t msgsize; + size_t msgidx; + + cbor_item_t *items; + size_t itemidx; + size_t maxitems; +} cbor_reader_t; + +typedef struct { + uint8_t *buf; + size_t bufsize; + size_t bufidx; +} cbor_writer_t; + +/** + * Initialize the reader for CBOR encoded messages. + * + * @param[in,out] reader reader context for the actual encoded message + * @param[out] items a pointer to item buffers + * @param[in] maxitems the maximum number of items to be stored in @p items + */ +void cbor_reader_init(cbor_reader_t *reader, cbor_item_t *items, size_t maxitems); +void cbor_writer_init(cbor_writer_t *writer, void *buf, size_t bufsize); +size_t cbor_writer_len(cbor_writer_t const *writer); +uint8_t const *cbor_writer_get_encoded(cbor_writer_t const *writer); + +cbor_item_data_t cbor_get_item_type(cbor_item_t const *item); +size_t cbor_get_item_size(cbor_item_t const *item); + +uint8_t cbor_get_following_bytes(uint8_t additional_info); + +size_t cbor_copy(uint8_t *dst, uint8_t const *src, size_t len); +size_t cbor_copy_be(uint8_t *dst, uint8_t const *src, size_t len); + +#if defined(__cplusplus) +} +#endif + +#endif /* CBOR_BASE_H */ diff --git a/include/linux/cbor/cbor.h b/include/linux/cbor/cbor.h new file mode 100644 index 000000000000..92d69ac7ae40 --- /dev/null +++ b/include/linux/cbor/cbor.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: MIT */ +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#ifndef CBOR_H +#define CBOR_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#include <linux/cbor/parser.h> +#include <linux/cbor/decoder.h> +#include <linux/cbor/encoder.h> +#include <linux/cbor/helper.h> + +#if defined(__cplusplus) +} +#endif + +#endif /* CBOR_H */ diff --git a/include/linux/cbor/decoder.h b/include/linux/cbor/decoder.h new file mode 100644 index 000000000000..846f0d215662 --- /dev/null +++ b/include/linux/cbor/decoder.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: MIT */ +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#ifndef CBOR_DECODER_H +#define CBOR_DECODER_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#include <linux/cbor/base.h> + +/** + * Decode a CBOR data item + * + * @param[in] reader reader context for the actual encoded message + * @param[in] item meta data about the item to be decoded + * @param[out] buf the buffer where decoded value to be written in + * @param[in] bufsize the buffer size + * + * @return a code of @ref cbor_error_t + */ +cbor_error_t cbor_decode(cbor_reader_t const *reader, cbor_item_t const *item, + void *buf, size_t bufsize); +/** + * Get the pointer to an item value + * + * @param[in] reader reader context for the actual encoded message + * @param[in] item meta data about the item to be decoded + * + * @return the pointer to the item value + */ +void const *cbor_decode_pointer(cbor_reader_t const *reader, + cbor_item_t const *item); + +#if defined(__cplusplus) +} +#endif + +#endif /* CBOR_DECODER_H */ diff --git a/include/linux/cbor/encoder.h b/include/linux/cbor/encoder.h new file mode 100644 index 000000000000..360568825454 --- /dev/null +++ b/include/linux/cbor/encoder.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: MIT */ +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#ifndef CBOR_ENCODER_H +#define CBOR_ENCODER_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#include <linux/cbor/base.h> + +cbor_error_t cbor_encode_unsigned_integer(cbor_writer_t *writer, uint64_t value); +cbor_error_t cbor_encode_negative_integer(cbor_writer_t *writer, int64_t value); + +cbor_error_t cbor_encode_byte_string(cbor_writer_t *writer, + uint8_t const *data, size_t datasize); +cbor_error_t cbor_encode_byte_string_indefinite(cbor_writer_t *writer); + +cbor_error_t cbor_encode_text_string(cbor_writer_t *writer, + char const *text, size_t textsize); +cbor_error_t cbor_encode_null_terminated_text_string(cbor_writer_t *writer, + char const *text); +cbor_error_t cbor_encode_text_string_indefinite(cbor_writer_t *writer); + +cbor_error_t cbor_encode_array(cbor_writer_t *writer, size_t length); +cbor_error_t cbor_encode_array_indefinite(cbor_writer_t *writer); + +cbor_error_t cbor_encode_map(cbor_writer_t *writer, size_t length); +cbor_error_t cbor_encode_map_indefinite(cbor_writer_t *writer); + +cbor_error_t cbor_encode_break(cbor_writer_t *writer); + +cbor_error_t cbor_encode_simple(cbor_writer_t *writer, uint8_t value); +cbor_error_t cbor_encode_bool(cbor_writer_t *writer, bool value); +cbor_error_t cbor_encode_null(cbor_writer_t *writer); +cbor_error_t cbor_encode_undefined(cbor_writer_t *writer); + +cbor_error_t cbor_encode_float(cbor_writer_t *writer, float value); +cbor_error_t cbor_encode_double(cbor_writer_t *writer, double value); + +#if defined(__cplusplus) +} +#endif + +#endif /* CBOR_ENCODER_H */ diff --git a/include/linux/cbor/helper.h b/include/linux/cbor/helper.h new file mode 100644 index 000000000000..d366583d2c54 --- /dev/null +++ b/include/linux/cbor/helper.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: MIT */ +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#ifndef CBOR_HELPER_H +#define CBOR_HELPER_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#include <linux/cbor/base.h> + +struct cbor_parser { + const void *key; + size_t keylen; + void (*run)(const cbor_reader_t *reader, + const struct cbor_parser *parser, + const cbor_item_t *item, void *arg); +}; + +bool cbor_unmarshal(cbor_reader_t *reader, + const struct cbor_parser *parsers, size_t nr_parsers, + const void *msg, size_t msglen, void *arg); + +size_t cbor_iterate(const cbor_reader_t *reader, + const cbor_item_t *parent, + void (*callback_each)(const cbor_reader_t *reader, + const cbor_item_t *item, const cbor_item_t *parent, + void *arg), + void *arg); + +const char *cbor_stringify_error(cbor_error_t err); +const char *cbor_stringify_item(cbor_item_t *item); + +#if defined(__cplusplus) +} +#endif + +#endif /* CBOR_HELPER_H */ diff --git a/include/linux/cbor/ieee754.h b/include/linux/cbor/ieee754.h new file mode 100644 index 000000000000..1362f3774d7c --- /dev/null +++ b/include/linux/cbor/ieee754.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: MIT */ +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#ifndef CBOR_IEEE754_H +#define CBOR_IEEE754_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#include <linux/cbor/base.h> + +typedef union { + uint16_t value; + struct { + uint32_t m: 10; + uint32_t e: 5; + uint32_t sign: 1; + } components; +} ieee754_half_t; + +typedef union { + float value; + struct { + uint32_t m: 23; + uint32_t e: 8; + uint32_t sign: 1; + } components; +} ieee754_single_t; + +typedef union { + double value; + struct { + uint64_t m: 52; + uint64_t e: 11; + uint64_t sign: 1; + } components; +} ieee754_double_t; + +uint16_t ieee754_convert_single_to_half(float value); +double ieee754_convert_half_to_double(uint16_t value); + +bool ieee754_is_shrinkable_to_half(float value); +bool ieee754_is_shrinkable_to_single(double value); + +#if defined(__cplusplus) +} +#endif + +#endif /* CBOR_IEEE754_H */ diff --git a/include/linux/cbor/parser.h b/include/linux/cbor/parser.h new file mode 100644 index 000000000000..554004799f0a --- /dev/null +++ b/include/linux/cbor/parser.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: MIT */ +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#ifndef CBOR_PARSER_H +#define CBOR_PARSER_H + +#if defined(__cplusplus) +extern "C" { +#endif + +#include <linux/cbor/base.h> + +/** + * Parse the encoded CBOR messages into items. + * + * @param[in,out] reader reader context for the actual encoded message + * @param[in] msg CBOR encoded message + * @param[in] msgsize the @p msg size in bytes + * @param[out] nitems_parsed the number of items parsed gets stored if not null + * + * @return a code of @ref cbor_error_t + */ +cbor_error_t cbor_parse(cbor_reader_t *reader, void const *msg, size_t msgsize, + size_t *nitems_parsed); + +#if defined(__cplusplus) +} +#endif + +#endif /* CBOR_PARSER_H */ diff --git a/lib/Kconfig b/lib/Kconfig index c686f4adc124..12fb3d68cd9a 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -764,3 +764,6 @@ config ASN1_ENCODER config POLYNOMIAL tristate + +config CBOR + tristate diff --git a/lib/Makefile b/lib/Makefile index 740109b6e2c8..287f3dcaff31 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -317,6 +317,8 @@ obj-$(CONFIG_ASN1_ENCODER) += asn1_encoder.o obj-$(CONFIG_FONT_SUPPORT) += fonts/ +obj-$(CONFIG_CBOR) += cbor/ + hostprogs := gen_crc32table hostprogs += gen_crc64table clean-files := crc32table.h diff --git a/lib/cbor/Makefile b/lib/cbor/Makefile new file mode 100644 index 000000000000..6b090ae0f4a8 --- /dev/null +++ b/lib/cbor/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_CBOR) += cbor.o + +cbor-y := \ + common.o \ + decoder.o \ + encoder.o \ + helper.o \ + parser.o \ + +cbor-$(CONFIG_CBOR_FLOAT) += ieee754.o diff --git a/lib/cbor/common.c b/lib/cbor/common.c new file mode 100644 index 000000000000..a4677a9bc0a3 --- /dev/null +++ b/lib/cbor/common.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: MIT +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#include <linux/cbor/base.h> +#include <linux/module.h> + +#if !defined(assert) +#define assert(expr) +#endif + +static size_t copy_le(uint8_t *dst, uint8_t const *src, size_t len) +{ + for (size_t i = 0; i < len; i++) + dst[len - i - 1] = src[i]; + + return len; +} + +static size_t copy_be(uint8_t *dst, uint8_t const *src, size_t len) +{ + for (size_t i = 0; i < len; i++) + dst[i] = src[i]; + + return len; +} + +size_t cbor_copy(uint8_t *dst, uint8_t const *src, size_t len) +{ +#if defined(CBOR_BIG_ENDIAN) + return copy_be(dst, src, len); +#else + return copy_le(dst, src, len); +#endif +} +EXPORT_SYMBOL_GPL(cbor_copy); + +size_t cbor_copy_be(uint8_t *dst, uint8_t const *src, size_t len) +{ + return copy_be(dst, src, len); +} +EXPORT_SYMBOL_GPL(cbor_copy_be); + +uint8_t cbor_get_following_bytes(uint8_t additional_info) +{ + if (additional_info < 24) + return 0; + else if (additional_info == 31) + return (uint8_t)CBOR_INDEFINITE_VALUE; + else if (additional_info >= 28) + return (uint8_t)CBOR_RESERVED_VALUE; + + return (uint8_t)(1u << (additional_info - 24)); +} +EXPORT_SYMBOL_GPL(cbor_get_following_bytes); + +cbor_item_data_t cbor_get_item_type(cbor_item_t const *item) +{ + return item->type; +} +EXPORT_SYMBOL_GPL(cbor_get_item_type); + +size_t cbor_get_item_size(cbor_item_t const *item) +{ + return item->size; +} +EXPORT_SYMBOL_GPL(cbor_get_item_size); + +void cbor_reader_init(cbor_reader_t *reader, cbor_item_t *items, size_t maxitems) +{ + assert(reader != NULL); + + reader->items = items; + reader->maxitems = maxitems; + reader->itemidx = 0; +} +EXPORT_SYMBOL_GPL(cbor_reader_init); + +void cbor_writer_init(cbor_writer_t *writer, void *buf, size_t bufsize) +{ + assert(writer != NULL); + assert(buf != NULL); + + writer->buf = (uint8_t *)buf; + writer->bufsize = bufsize; + writer->bufidx = 0; +} +EXPORT_SYMBOL_GPL(cbor_writer_init); + +size_t cbor_writer_len(cbor_writer_t const *writer) +{ + return writer->bufidx; +} +EXPORT_SYMBOL_GPL(cbor_writer_len); + +uint8_t const *cbor_writer_get_encoded(cbor_writer_t const *writer) +{ + return (uint8_t const *)writer->buf; +} +EXPORT_SYMBOL_GPL(cbor_writer_get_encoded); + +MODULE_DESCRIPTION("CBOR helper functions"); +MODULE_AUTHOR("Kyunghwan Kwon"); +MODULE_LICENSE("GPL"); diff --git a/lib/cbor/decoder.c b/lib/cbor/decoder.c new file mode 100644 index 000000000000..1ec0b17ecf6c --- /dev/null +++ b/lib/cbor/decoder.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: MIT +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#include <linux/cbor/decoder.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/module.h> + +#if !defined(MIN) +#define MIN(a, b) (((a) > (b)) ? (b) : (a)) +#endif + +typedef cbor_error_t (*item_decoder_t)(cbor_item_t const *item, + uint8_t const *msg, uint8_t *buf, size_t bufsize); + +static cbor_error_t decode_pass(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize); +static cbor_error_t decode_integer(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize); +static cbor_error_t decode_string(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize); +static cbor_error_t decode_float(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize); +static cbor_error_t decode_simple(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize); + +static const item_decoder_t decoders[] = { + decode_pass, /* 0: CBOR_ITEM_UNKNOWN */ + decode_integer, /* 1: CBOR_ITEM_INTEGER */ + decode_string, /* 2: CBOR_ITEM_STRING */ + decode_pass, /* 3: CBOR_ITEM_ARRAY */ + decode_pass, /* 4: CBOR_ITEM_MAP */ + decode_float, /* 5: CBOR_ITEM_FLOAT */ + decode_simple, /* 6: CBOR_ITEM_SIMPLE_VALUE */ +}; + +static uint8_t get_simple_value(uint8_t val) +{ + switch (val) { + case 20: /* false */ + return 0; + case 21: /* true */ + return 1; + case 22: /* null */ + return '\0'; + case 23: /* undefined */ + default: + return val; + } +} + +static bool is_break(cbor_item_t const *item) +{ + return item->type == CBOR_ITEM_FLOAT && item->size == 0xff; +} + +static cbor_error_t decode_unsigned_integer(cbor_item_t const *item, + uint8_t const *msg, uint8_t *buf, size_t bufsize) +{ + uint8_t additional_info = get_cbor_additional_info(msg[item->offset]); + uint8_t following_bytes = cbor_get_following_bytes(additional_info); + + if (following_bytes == 0) + buf[0] = additional_info; + + cbor_copy(buf, &msg[item->offset + 1], following_bytes); + + (void)bufsize; + return CBOR_SUCCESS; +} + +static cbor_error_t decode_negative_integer(cbor_item_t const *item, + uint8_t const *msg, uint8_t *buf, size_t bufsize) +{ + cbor_error_t err = decode_unsigned_integer(item, msg, buf, bufsize); + + if (err != CBOR_SUCCESS) + return err; + + uint64_t val = 0; + size_t len = item->size ? item->size : 1; + + cbor_copy_be((uint8_t *)&val, buf, len); + + val = ~val; + + /* + * The value becomes a positive one if the data type size of the + * variable is larger than the value size. So we set MSB first here to + * keep it negative. + */ + for (uint8_t i = 0; i < MIN(bufsize, 8u); i++) + buf[i] = 0xff; + + cbor_copy_be(buf, (uint8_t *)&val, len); + + return CBOR_SUCCESS; +} + +static cbor_error_t decode_integer(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize) +{ + switch (get_cbor_major_type(msg[item->offset])) { + case 0: /* unsigned integer */ + return decode_unsigned_integer(item, msg, buf, bufsize); + case 1: /* negative integer */ + return decode_negative_integer(item, msg, buf, bufsize); + default: + return CBOR_ILLEGAL; + } +} + +static cbor_error_t decode_string(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize) +{ + for (size_t i = 0; i < item->size; i++) + buf[i] = msg[item->offset + i]; + + (void)bufsize; + return CBOR_SUCCESS; +} + +static cbor_error_t decode_float(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize) +{ + return decode_unsigned_integer(item, msg, buf, bufsize); +} + +static cbor_error_t decode_simple(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize) +{ + cbor_error_t err = decode_unsigned_integer(item, msg, buf, bufsize); + + buf[0] = get_simple_value(buf[0]); + + return err; +} + +static cbor_error_t decode_pass(cbor_item_t const *item, uint8_t const *msg, + uint8_t *buf, size_t bufsize) +{ + (void)item; + (void)msg; + (void)buf; + (void)bufsize; + return CBOR_SUCCESS; +} + +void const *cbor_decode_pointer(cbor_reader_t const *reader, + cbor_item_t const *item) +{ + return &reader->msg[item->offset]; +} +EXPORT_SYMBOL_GPL(cbor_decode_pointer); + +cbor_error_t cbor_decode(cbor_reader_t const *reader, cbor_item_t const *item, + void *buf, size_t bufsize) +{ + if (is_break(item)) + return CBOR_BREAK; + if (item->size > bufsize || bufsize == 0 || buf == NULL) + return CBOR_OVERRUN; + + memset(buf, 0, bufsize); + + return decoders[item->type](item, reader->msg, (uint8_t *)buf, bufsize); +} +EXPORT_SYMBOL_GPL(cbor_decode); diff --git a/lib/cbor/encoder.c b/lib/cbor/encoder.c new file mode 100644 index 000000000000..9b3f8ac8f670 --- /dev/null +++ b/lib/cbor/encoder.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: MIT +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#include <linux/cbor/encoder.h> +#include <linux/string.h> +#include <linux/module.h> + +#ifdef CONFIG_CBOR_FLOAT +#include <linux/cbor/ieee754.h> +#endif + +#define MAJOR_TYPE_BIT 5 + +#if !defined(MIN) +#define MIN(a, b) (((a) > (b)) ? (b) : (a)) +#endif + +static uint8_t get_additional_info(uint64_t value) +{ + uint8_t additional_info = 0; + + if (value & ~(0x100000000ull - 1)) /* 8-byte following */ + additional_info = 27; + else if (value & ~(0x10000ull - 1)) /* 4-byte following */ + additional_info = 26; + else if (value & ~(0x100ull - 1)) /* 2-byte following */ + additional_info = 25; + else if (value >= 24) /* 1-byte following */ + additional_info = 24; + else /* 0 ~ 23 */ + additional_info = (uint8_t)value; + + return additional_info; +} + +static cbor_error_t encode_core(cbor_writer_t *writer, uint8_t major_type, + uint8_t const *data, uint64_t datasize, bool indefinite) +{ + uint8_t *buf = &writer->buf[writer->bufidx]; + uint8_t additional_info = get_additional_info(datasize); + uint8_t following_bytes = cbor_get_following_bytes(additional_info); + + if (indefinite) { + additional_info = 31; + following_bytes = 0; + } + + size_t bytes_to_write = (size_t)datasize + following_bytes + 1; + /* + * NOTE: if not string, `datasize` is the actual value to be written. + * And the `following_bytes` is the length of it. + */ + if (!(major_type == 2 || major_type == 3)) + bytes_to_write -= (size_t)datasize; + + if (bytes_to_write > (writer->bufsize - writer->bufidx)) + return CBOR_OVERRUN; + + buf[0] = (uint8_t)(major_type << MAJOR_TYPE_BIT) | additional_info; + cbor_copy(&buf[1], (uint8_t const *)&datasize, following_bytes); + if (data != NULL) + cbor_copy_be(&buf[1 + following_bytes], data, (size_t)datasize); + + writer->bufidx += bytes_to_write; + + return CBOR_SUCCESS; +} + +static cbor_error_t encode_simple(cbor_writer_t *writer, uint8_t value) +{ + return encode_core(writer, 7, NULL, value, false); +} + +cbor_error_t cbor_encode_unsigned_integer(cbor_writer_t *writer, uint64_t value) +{ + return encode_core(writer, 0, NULL, value, false); +} +EXPORT_SYMBOL_GPL(cbor_encode_unsigned_integer); + +cbor_error_t cbor_encode_negative_integer(cbor_writer_t *writer, int64_t value) +{ + return encode_core(writer, 1, NULL, ((uint64_t)-value) - 1, false); +} +EXPORT_SYMBOL_GPL(cbor_encode_negative_integer); + +cbor_error_t cbor_encode_byte_string(cbor_writer_t *writer, + uint8_t const *data, size_t datasize) +{ + return encode_core(writer, 2, data, datasize, false); +} +EXPORT_SYMBOL_GPL(cbor_encode_byte_string); + +cbor_error_t cbor_encode_byte_string_indefinite(cbor_writer_t *writer) +{ + return encode_core(writer, 2, NULL, 0, true); +} +EXPORT_SYMBOL_GPL(cbor_encode_byte_string_indefinite); + + +cbor_error_t cbor_encode_text_string(cbor_writer_t *writer, + char const *text, size_t textsize) +{ + return encode_core(writer, 3, + (uint8_t const *)text, textsize, false); +} +EXPORT_SYMBOL_GPL(cbor_encode_text_string); + +cbor_error_t cbor_encode_null_terminated_text_string(cbor_writer_t *writer, + char const *text) +{ + size_t len = 0; + + if (text != NULL) + len = MIN(strlen(text), writer->bufsize - writer->bufidx); + + return encode_core(writer, 3, (uint8_t const *)text, len, false); +} +EXPORT_SYMBOL_GPL(cbor_encode_null_terminated_text_string); + +cbor_error_t cbor_encode_array(cbor_writer_t *writer, size_t length) +{ + return encode_core(writer, 4, NULL, length, false); +} +EXPORT_SYMBOL_GPL(cbor_encode_array); + +cbor_error_t cbor_encode_array_indefinite(cbor_writer_t *writer) +{ + return encode_core(writer, 4, NULL, 0, true); +} +EXPORT_SYMBOL_GPL(cbor_encode_array_indefinite); + +cbor_error_t cbor_encode_map(cbor_writer_t *writer, size_t length) +{ + return encode_core(writer, 5, NULL, length, false); +} +EXPORT_SYMBOL_GPL(cbor_encode_map); + +cbor_error_t cbor_encode_map_indefinite(cbor_writer_t *writer) +{ + return encode_core(writer, 5, NULL, 0, true); +} +EXPORT_SYMBOL_GPL(cbor_encode_map_indefinite); + +cbor_error_t cbor_encode_break(cbor_writer_t *writer) +{ + return encode_core(writer, 7, NULL, 0xff, true); +} +EXPORT_SYMBOL_GPL(cbor_encode_break); + +cbor_error_t cbor_encode_simple(cbor_writer_t *writer, uint8_t value) +{ + return encode_simple(writer, value); +} +EXPORT_SYMBOL_GPL(cbor_encode_simple); + +cbor_error_t cbor_encode_bool(cbor_writer_t *writer, bool value) +{ + return encode_simple(writer, (uint8_t)(value + 20)); +} +EXPORT_SYMBOL_GPL(cbor_encode_bool); + +cbor_error_t cbor_encode_null(cbor_writer_t *writer) +{ + return encode_simple(writer, 22); +} +EXPORT_SYMBOL_GPL(cbor_encode_null); + +cbor_error_t cbor_encode_undefined(cbor_writer_t *writer) +{ + return encode_simple(writer, 23); +} +EXPORT_SYMBOL_GPL(cbor_encode_undefined); + +#ifdef CONFIG_CBOR_FLOAT +static cbor_error_t encode_float(cbor_writer_t *writer, float value) +{ + if (ieee754_is_shrinkable_to_half(value)) { + uint16_t half = ieee754_convert_single_to_half(value); + + writer->buf[writer->bufidx++] = 0xF9; + writer->bufidx += cbor_copy(&writer->buf[writer->bufidx], + (uint8_t const *)&half, sizeof(half)); + + return CBOR_SUCCESS; + } + + writer->buf[writer->bufidx++] = 0xFA; + writer->bufidx += cbor_copy(&writer->buf[writer->bufidx], + (uint8_t const *)&value, sizeof(value)); + + return CBOR_SUCCESS; +} + +cbor_error_t cbor_encode_float(cbor_writer_t *writer, float value) +{ + return encode_float(writer, value); +} + +cbor_error_t cbor_encode_double(cbor_writer_t *writer, double value) +{ + if (ieee754_is_shrinkable_to_single(value)) + return encode_float(writer, (float)value); + + writer->buf[writer->bufidx++] = 0xFB; + writer->bufidx += cbor_copy(&writer->buf[writer->bufidx], + (uint8_t const *)&value, sizeof(value)); + + return CBOR_SUCCESS; +} +#endif + +cbor_error_t cbor_encode_text_string_indefinite(cbor_writer_t *writer) +{ + return encode_core(writer, 3, NULL, 0, true); +} +EXPORT_SYMBOL_GPL(cbor_encode_text_string_indefinite); diff --git a/lib/cbor/helper.c b/lib/cbor/helper.c new file mode 100644 index 000000000000..f7b3e7deea67 --- /dev/null +++ b/lib/cbor/helper.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: MIT +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#include <linux/cbor/helper.h> +#include <linux/cbor/parser.h> +#include <linux/cbor/decoder.h> + +#include <linux/string.h> +#include <linux/module.h> + +struct parser_ctx { + const struct cbor_parser *parsers; + size_t nr_parsers; + void *arg; +}; + +static const struct cbor_parser *get_parser(const struct parser_ctx *ctx, + intptr_t intkey, const void *strkey, size_t strkey_len) +{ + for (size_t i = 0; i < ctx->nr_parsers; i++) { + const struct cbor_parser *p = &ctx->parsers[i]; + + if (!p->key) + continue; + + if (strkey && strkey_len && p->keylen >= strkey_len) { + if (memcmp(p->key, strkey, strkey_len) == 0) + return p; + } else if (intkey == (intptr_t)p->key) { + return p; + } + } + + return NULL; +} + +static void parse_item(const cbor_reader_t *reader, const cbor_item_t *item, + const cbor_item_t *parent, void *arg) +{ + struct parser_ctx *ctx = (struct parser_ctx *)arg; + const void *strkey = NULL; + size_t strkey_len = 0; + intptr_t intkey = -1; + + if (parent && parent->type == CBOR_ITEM_MAP) { + if ((item - parent) % 2) { /* key */ + return; + } + + if ((item-1)->type == CBOR_ITEM_INTEGER) { + cbor_decode(reader, item-1, &intkey, sizeof(intkey)); + } else { + strkey = cbor_decode_pointer(reader, item-1); + strkey_len = (item-1)->size; + } + } + + if (strkey || intkey != -1) { + const struct cbor_parser *parser = get_parser(ctx, + intkey, strkey, strkey_len); + + if (parser && parser->run) + parser->run(reader, parser, item, ctx->arg); + } +} + +static size_t iterate_each(const cbor_reader_t *reader, + const cbor_item_t *items, size_t nr_items, + const cbor_item_t *parent, + void (*callback_each)(const cbor_reader_t *reader, + const cbor_item_t *item, const cbor_item_t *parent, + void *arg), + void *arg) +{ + size_t offset = 0; + size_t i = 0; + + for (i = 0; i < nr_items; i++) { + const cbor_item_t *item = &items[i+offset]; + + if (item->type == CBOR_ITEM_MAP + || item->type == CBOR_ITEM_ARRAY) { + size_t len = item->type == CBOR_ITEM_MAP ? + item->size*2 : item->size; + offset += iterate_each(reader, item+1, len, item, + callback_each, arg); + continue; + } + + if (cbor_decode(reader, item, 0, 0) == CBOR_BREAK) + break; + + (*callback_each)(reader, item, parent, arg); + } + + return i + offset; +} + +bool cbor_unmarshal(cbor_reader_t *reader, + const struct cbor_parser *parsers, size_t nr_parsers, + const void *msg, size_t msglen, void *arg) +{ + size_t n; + cbor_error_t err = cbor_parse(reader, msg, msglen, &n); + + if (err != CBOR_SUCCESS && err != CBOR_BREAK) + return false; + + struct parser_ctx ctx = { + .parsers = parsers, + .nr_parsers = nr_parsers, + .arg = arg, + }; + + iterate_each(reader, reader->items, n, 0, parse_item, &ctx); + + return true; +} +EXPORT_SYMBOL_GPL(cbor_unmarshal); + +size_t cbor_iterate(const cbor_reader_t *reader, + const cbor_item_t *parent, + void (*callback_each)(const cbor_reader_t *reader, + const cbor_item_t *item, const cbor_item_t *parent, + void *arg), + void *arg) +{ + return iterate_each(reader, reader->items, reader->itemidx, + parent, callback_each, arg); +} +EXPORT_SYMBOL_GPL(cbor_iterate); + +const char *cbor_stringify_error(cbor_error_t err) +{ + switch (err) { + case CBOR_SUCCESS: + return "success"; + case CBOR_INVALID: + return "invalid"; + case CBOR_OVERRUN: + return "out of memory"; + case CBOR_BREAK: + return "break"; + case CBOR_EXCESSIVE: + return "too deep recursion"; + case CBOR_ILLEGAL: + default: + return "not well-formed"; + } +} +EXPORT_SYMBOL_GPL(cbor_stringify_error); + +const char *cbor_stringify_item(cbor_item_t *item) +{ + switch (item->type) { + case CBOR_ITEM_INTEGER: + return "integer"; + case CBOR_ITEM_STRING: + return "string"; + case CBOR_ITEM_ARRAY: + return "array"; + case CBOR_ITEM_MAP: + return "map"; + case CBOR_ITEM_FLOAT: + return "float"; + case CBOR_ITEM_SIMPLE_VALUE: + return "simple value"; + case CBOR_ITEM_UNKNOWN: + default: + return "unknown"; + } +} +EXPORT_SYMBOL_GPL(cbor_stringify_item); diff --git a/lib/cbor/ieee754.c b/lib/cbor/ieee754.c new file mode 100644 index 000000000000..acf180a99f01 --- /dev/null +++ b/lib/cbor/ieee754.c @@ -0,0 +1,205 @@ +// SPDX-License-Identifier: MIT +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +/* + * | precision | sign | exponent | mantissa | bias | exp range | + * | --------- | ---- | -------- | -------- | ---- | ------------ | + * | half | 1 | 5 | 10 | 15 | -14 ~ 15 | + * | single | 1 | 8 | 23 | 127 | -126 ~ 127 | + * | double | 1 | 11 | 52 | 1023 | -1022 ~ 1023 | + * + * ## Special cases + * | s | e | m | desc. | + * | - | -----| -- | ------------- | + * | 0 | 0 | 0 | +0.0 | + * | 1 | 0 | 0 | -0.0 | + * | 0 | 0 | !0 | 0.m * 2^-126 | + * | 1 | 0 | !0 | -0.m * 2^-126 | + * | 0 | 0xff | 0 | infinity | + * | 1 | 0xff | 0 | -infinity | + * | X | 0xff | -1 | Quiet NaN | + * | X | 0xff | !0 | Signaling NaN | + * + * ## Terms + * - f: source bias + * - t: target bias + * - e: exponent + * - m: mantissa + */ + +#include <linux/cbor/ieee754.h> + +#define BIAS_HALF 15 +#define BIAS_SINGLE 127 +#define BIAS_DOUBLE 1023 + +#define E_MASK_HALF ((1u << 5) - 1) +#define E_MASK_SINGLE ((1ul << 8) - 1) +#define E_MASK_DOUBLE ((1ul << 11) - 1) + +#define M_BIT_HALF 10 +#define M_BIT_SINGLE 23 +#define M_BIT_DOUBLE 52 + +#define M_MASK_HALF ((1u << M_BIT_HALF) - 1) +#define M_MASK_SINGLE ((1ul << M_BIT_SINGLE) - 1) +#define M_MASK_DOUBLE ((1ull << M_BIT_DOUBLE) - 1) + +static int find_last_set_bit(unsigned int value) +{ + int cnt = 0; + + while (value != 0) { + value >>= 1; + cnt++; + } + + return cnt; +} + +static bool is_over_range(unsigned int e, unsigned int f, unsigned int t) +{ + return e > (f + t); +} + +static bool is_under_range(unsigned int e, unsigned int f, unsigned int t) +{ + return e < (f - t + 1); +} + +static bool is_in_range(unsigned int e, unsigned int f, unsigned int t) +{ + return !is_over_range(e, f, t) && !is_under_range(e, f, t); +} + +static bool is_in_subrange(unsigned int e, unsigned int target_m_bits, + unsigned int f, unsigned int t) +{ + return is_under_range(e, f, t) && ((f - e - t) < target_m_bits); +} + +static bool is_precision_lost(uint64_t m, unsigned int f, unsigned int t) +{ + return (m & ((1ull << (f - t)) - 1)) != 0; +} + +uint16_t ieee754_convert_single_to_half(float value) +{ + ieee754_single_t single = { .value = value }; + ieee754_half_t half = { .value = 0 }; + uint8_t exp = M_BIT_SINGLE - M_BIT_HALF; + + half.components.sign = single.components.sign; + if (single.components.e == E_MASK_SINGLE) { /* NaN or infinity */ + half.components.e = E_MASK_HALF; + } else if (is_over_range(single.components.e, BIAS_SINGLE, BIAS_HALF)) { + /* make it NaN */ + half.components.e = E_MASK_HALF; + single.components.m = 0; + } else if (is_under_range(single.components.e, BIAS_SINGLE, BIAS_HALF)) { + /* expand the exponent to the mantissa to make it subnormal */ + exp = (uint8_t)(exp + ((BIAS_SINGLE - single.components.e) - BIAS_HALF)); + single.components.m = M_MASK_SINGLE; + } else { /* zero, normal */ + if (single.components.e != 0) { + half.components.e = (uint8_t)(single.components.e + - BIAS_SINGLE + BIAS_HALF) & E_MASK_HALF; + } + } + + /* precision may be lost discarding outrange lower bits */ + half.components.m = ((uint32_t)single.components.m >> exp) & M_MASK_HALF; + + return half.value; +} + +double ieee754_convert_half_to_double(uint16_t value) +{ + ieee754_half_t half = { .value = value }; + ieee754_double_t d; + + d.components.sign = half.components.sign; + d.components.e = half.components.e; + d.components.m = half.components.m; + + if (half.components.e == E_MASK_HALF) { /* NaN or infinity */ + d.components.e = E_MASK_DOUBLE; + if (half.components.m == M_MASK_HALF) /* Quiet NaN */ + d.components.m = M_MASK_DOUBLE; + else if (half.components.m != 0) /* Signaling NaN */ + d.components.m = (1ull << (M_BIT_DOUBLE - 1)); + } else if (half.components.e == 0) { /* zero or subnormal */ + if (half.components.m != 0) { /* subnormal */ + /* find the leading 1 to nomalize */ + uint64_t leading_shift = (uint64_t)(M_BIT_HALF - + find_last_set_bit(half.components.m) + 1); + d.components.m <<= leading_shift; + d.components.e = + (BIAS_DOUBLE - BIAS_HALF - leading_shift + 1) + & E_MASK_DOUBLE; + } + } else { /* normal */ + d.components.e = (uint32_t)(BIAS_DOUBLE + (half.components.e + - BIAS_HALF)) & 0x7FFu/*11-bit*/; + } + + d.components.m <<= M_BIT_DOUBLE - M_BIT_HALF; + + return d.value; +} + +bool ieee754_is_shrinkable_to_half(float value) +{ + ieee754_single_t single = { .value = value }; + + if (single.components.e == 0) { + if (single.components.m == 0) { /* zero */ + return true; + } + /* subnormal */ + if (!is_precision_lost(single.components.m, + M_BIT_SINGLE, M_BIT_HALF)) { + return true; + } + } else if (single.components.e == E_MASK_SINGLE) { /* NaN or infinity */ + return true; + } else if (is_in_range(single.components.e, BIAS_SINGLE, BIAS_HALF) && + !is_precision_lost(single.components.m, M_BIT_SINGLE, + M_BIT_HALF)) { + return true; + } else if (is_in_subrange(single.components.e, M_BIT_HALF, + BIAS_SINGLE, BIAS_HALF)) { + return true; + } + + return false; +} + +bool ieee754_is_shrinkable_to_single(double value) +{ + ieee754_double_t d = { .value = value }; + + if (d.components.e == 0) { + if (d.components.m == 0) { /* zero */ + return true; + } + /* subnormal */ + if (!is_precision_lost(d.components.m, + M_BIT_DOUBLE, M_BIT_SINGLE)) { + return true; + } + } else if (d.components.e == E_MASK_DOUBLE) { /* NaN or infinity */ + return true; + } else if (is_in_range(d.components.e, BIAS_DOUBLE, BIAS_SINGLE) && + !is_precision_lost(d.components.m, M_BIT_DOUBLE, + M_BIT_SINGLE)) { + return true; + } else if (is_in_subrange(d.components.e, M_BIT_SINGLE, + BIAS_DOUBLE, BIAS_SINGLE)) { + return true; + } + + return false; +} diff --git a/lib/cbor/parser.c b/lib/cbor/parser.c new file mode 100644 index 000000000000..c997834f7c48 --- /dev/null +++ b/lib/cbor/parser.c @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: MIT +/* + * SPDX-FileCopyrightText: 2021 Kyunghwan Kwon <k@mononn.com> + */ + +#include <linux/cbor/parser.h> +#include <linux/module.h> + +#if !defined(assert) +#define assert(expr) +#endif + +struct parser_context { + cbor_reader_t *reader; + + uint8_t major_type; + uint8_t additional_info; + uint8_t following_bytes; + + uint8_t recursion_depth; + + _Static_assert(CBOR_RECURSION_MAX_LEVEL < 256, ""); +}; + +typedef cbor_error_t (*type_parser_t)(struct parser_context *ctx); + +static cbor_error_t do_integer(struct parser_context *ctx); +static cbor_error_t do_string(struct parser_context *ctx); +static cbor_error_t do_recursive(struct parser_context *ctx); +static cbor_error_t do_tag(struct parser_context *ctx); +static cbor_error_t do_float_and_other(struct parser_context *ctx); + +/* 8 parsers for 3-bit major type */ +static const type_parser_t parsers[] = { + do_integer, /* 0: unsigned integer */ + do_integer, /* 1: negative integer */ + do_string, /* 2: byte string */ + do_string, /* 3: text string encoded as utf-8 */ + do_recursive, /* 4: array */ + do_recursive, /* 5: map */ + do_tag, /* 6: tag */ + do_float_and_other, /* 7: float, simple value, and break */ +}; + +static bool has_valid_following_bytes(const struct parser_context *ctx, + cbor_error_t *err) +{ + *err = CBOR_SUCCESS; + + if (ctx->following_bytes == (uint8_t)CBOR_RESERVED_VALUE) { + *err = CBOR_ILLEGAL; + return false; + } else if (ctx->following_bytes == (uint8_t)CBOR_INDEFINITE_VALUE) { + return true; + } + + if ((ctx->following_bytes + 1u) + > ctx->reader->msgsize - ctx->reader->msgidx) { + *err = CBOR_ILLEGAL; + return false; + } + + return true; +} + +static size_t go_get_item_length(struct parser_context *ctx) +{ + uint64_t len = 0; + size_t offset = 0; + + if (ctx->following_bytes == (uint8_t)CBOR_INDEFINITE_VALUE) { + len = (uint64_t)CBOR_INDEFINITE_VALUE; + } else if (ctx->following_bytes == 0) { + len = ctx->additional_info; + } else { + const uint8_t *msg = &ctx->reader->msg[ctx->reader->msgidx]; + + cbor_copy((uint8_t *)&len, &msg[1], ctx->following_bytes); + offset = ctx->following_bytes; + } + + ctx->reader->msgidx += offset + 1; + + return (size_t)len; +} + +static cbor_error_t parse(struct parser_context *ctx, size_t maxitems) +{ + cbor_error_t err = CBOR_SUCCESS; + + if (++ctx->recursion_depth > CBOR_RECURSION_MAX_LEVEL) + return CBOR_EXCESSIVE; + + for (size_t i = 0; i < maxitems && + ctx->reader->itemidx < ctx->reader->maxitems && + ctx->reader->msgidx < ctx->reader->msgsize; i++) { + uint8_t val = ctx->reader->msg[ctx->reader->msgidx]; + + ctx->major_type = get_cbor_major_type(val); + ctx->additional_info = get_cbor_additional_info(val); + ctx->following_bytes = + cbor_get_following_bytes(ctx->additional_info); + + if (!has_valid_following_bytes(ctx, &err)) + break; + + err = parsers[ctx->major_type](ctx); + + if (err == CBOR_BREAK) { + if ((maxitems == (size_t)CBOR_INDEFINITE_VALUE) || + (ctx->reader->msgidx == + ctx->reader->msgsize)) { + break; + } + } else if (err != CBOR_SUCCESS) { + break; + } + + err = CBOR_SUCCESS; + } + + ctx->recursion_depth--; + + assert(ctx->msgidx <= ctx->msgsize); + + return err; +} + +static cbor_error_t do_integer(struct parser_context *ctx) +{ + if (ctx->following_bytes == (uint8_t)CBOR_INDEFINITE_VALUE) + return CBOR_ILLEGAL; + + cbor_item_t *item = &ctx->reader->items[ctx->reader->itemidx]; + + item->type = CBOR_ITEM_INTEGER; + item->size = (size_t)ctx->following_bytes; + item->offset = ctx->reader->msgidx; + + ctx->reader->msgidx += (size_t)(ctx->following_bytes + 1); + ctx->reader->itemidx++; + + return CBOR_SUCCESS; +} + +static cbor_error_t do_string(struct parser_context *ctx) +{ + cbor_item_t *item = &ctx->reader->items[ctx->reader->itemidx]; + size_t len = go_get_item_length(ctx); + + item->type = CBOR_ITEM_STRING; + item->size = len; + item->offset = ctx->reader->msgidx; + + if (len == (size_t)CBOR_INDEFINITE_VALUE) { + ctx->reader->itemidx++; + return parse(ctx, ctx->reader->maxitems - ctx->reader->itemidx); + } + if (len > ctx->reader->msgsize - ctx->reader->msgidx) + return CBOR_ILLEGAL; + + ctx->reader->msgidx += len; + ctx->reader->itemidx++; + + return CBOR_SUCCESS; +} + +static cbor_error_t do_recursive(struct parser_context *ctx) +{ + size_t current_item_index = ctx->reader->itemidx; + cbor_item_t *item = &ctx->reader->items[current_item_index]; + size_t len = go_get_item_length(ctx); + + item->type = (cbor_item_data_t)(ctx->major_type - 1); + item->offset = ctx->reader->msgidx; + item->size = len; + if (len != (size_t)CBOR_INDEFINITE_VALUE && + len > ctx->reader->msgsize - ctx->reader->msgidx) { + return CBOR_ILLEGAL; + } + + ctx->reader->itemidx++; + + return parse(ctx, len); +} + +/* TODO: Implement tag */ +static cbor_error_t do_tag(struct parser_context *ctx) +{ + (void)ctx; + return CBOR_INVALID; +} + +static cbor_error_t do_float_and_other(struct parser_context *ctx) +{ + cbor_item_t *item = &ctx->reader->items[ctx->reader->itemidx]; + cbor_error_t err = CBOR_SUCCESS; + + item->type = CBOR_ITEM_FLOAT; + item->size = (size_t)ctx->following_bytes; + item->offset = ctx->reader->msgidx; + + if (ctx->following_bytes == (uint8_t)CBOR_INDEFINITE_VALUE) { + ctx->reader->msgidx++; + ctx->reader->itemidx++; + return CBOR_BREAK; + } else if (!has_valid_following_bytes(ctx, &err)) { + return err; + } else if (ctx->following_bytes <= 1) { + item->type = CBOR_ITEM_SIMPLE_VALUE; + } + + ctx->reader->msgidx += item->size + 1; + ctx->reader->itemidx++; + + return err; +} + +cbor_error_t cbor_parse(cbor_reader_t *reader, void const *msg, size_t msgsize, + size_t *nitems_parsed) +{ + assert(reader->items != NULL); + reader->itemidx = 0; + + reader->msg = (uint8_t const *)msg; + reader->msgsize = msgsize; + reader->msgidx = 0; + + struct parser_context ctx = { + .reader = reader, + }; + + cbor_error_t err = parse(&ctx, reader->maxitems); + + if (err == CBOR_SUCCESS && reader->msgidx < reader->msgsize) + err = CBOR_OVERRUN; + + if (nitems_parsed != NULL) + *nitems_parsed = reader->itemidx; + + return err; +} +EXPORT_SYMBOL_GPL(cbor_parse);

[v4,1/2] Import CBOR library

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