diff --git a/.travis.yml b/.travis.yml deleted file mode 100644 index c8bf19f..0000000 --- a/.travis.yml +++ /dev/null @@ -1,46 +0,0 @@ -# Copyright 2019 Google LLC -# -# 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. - -language: rust -rust: - - nightly-2020-01-16 - -os: - - linux - - osx - -addons: - apt: - packages: - - "python3" - - "python3-pip" - - "python3-setuptools" - - "python3-wheel" - -cache: - - rust - - cargo - -before-install: - - openssl version - -install: - - rustup target add thumbv7em-none-eabi - - rustup component add rustfmt - - cargo install cargo-audit - -script: - - ./setup.sh - - cargo audit - - ./run_desktop_tests.sh diff --git a/Cargo.toml b/Cargo.toml index a11d0f7..8faf8dd 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -28,6 +28,7 @@ ram_storage = [] verbose = ["debug_ctap", "libtock_drivers/verbose_usb"] with_ctap1 = ["crypto/with_ctap1"] with_ctap2_1 = [] +with_nfc = ["libtock_drivers/with_nfc"] [dev-dependencies] elf2tab = "0.6.0" diff --git a/deploy.py b/deploy.py index 5cf210d..e1ec38f 100755 --- a/deploy.py +++ b/deploy.py @@ -846,6 +846,13 @@ if __name__ == "__main__": help=("Compiles the OpenSK application with backward compatible " "support for CTAP2.1 protocol."), ) + main_parser.add_argument( + "--nfc", + action="append_const", + const="with_nfc", + dest="features", + help=("Compiles the OpenSK application with support for nfc."), + ) main_parser.add_argument( "--regen-keys", action="store_true", diff --git a/fuzz/ctap2_commands_parameters_corpus.json b/fuzz/ctap2_commands_parameters_corpus.json new file mode 100644 index 0000000..8d5dbd8 --- /dev/null +++ b/fuzz/ctap2_commands_parameters_corpus.json @@ -0,0 +1,152 @@ +[ + { + "hex": "1903e8", + "cbor": "unsigned(1000)", + "description": "cbor value" + }, + { + "hex": "3829", + "cbor": "negative(41)", + "description": "cbor value" + }, + { + "hex": "c349010000000000000000", + "cbor": "-18446744073709551617", + "description": "cbor value" + }, + { + "hex": "f90000", + "cbor": "primitive(0)", + "description": "cbor value" + }, + { + "hex": "f90001", + "cbor": "primitive(1) = 5.960464477539063e-8", + "description": "cbor value" + }, + { + "hex": "fa7fc00000", + "cbor": "primitive(2143289344) = NaN", + "description": "cbor value" + }, + { + "hex": "f818", + "cbor": "simple(24)", + "description": "cbor value" + }, + { + "hex": "d74401020304", + "cbor": "tag 23(h'01020304')", + "description": "cbor value" + }, + { + "hex": "6449455446", + "cbor": "IETF", + "description": "cbor value" + }, + { + "hex": "62225c", + "cbor": "\"\\", + "description": "cbor value" + }, + { + "hex": "41a8", + "cbor": "bytes(a8)", + "description": "cbor value" + }, + { + "hex": "623a41", + "cbor": "text(:A)", + "description": "cbor value" + }, + { + "hex": "83019f0203ff820405", + "cbor": "array [1, [2, 3], [4, 5]]", + "description": "cbor value" + }, + { + "hex": "9f018202039f0405ffff", + "cbor": "indefinite length array [1, [2, 3], [4, 5]]", + "description": "cbor value" + }, + { + "hex": "5f44aabbccdd43eeff99ff", + "cbor": "indefinite byte string (_ h'AABBCCDD', h'EEFF99')", + "description": "cbor value" + }, + { + "hex": "7f657374726561646d696e67ff", + "cbor": "indefinite byte string (_ \"strea\", \"ming\")", + "description": "cbor value" + }, + { + "hex": "a26161016162820203", + "cbor": "map {\"a\": 1, \"b\": [2, 3]}", + "description": "cbor value" + }, + { + "hex": "bf6346756ef563416d7421ff", + "cbor": "indefinite length map {\"Fun\": true, \"Amt\": -2}", + "description": "cbor value" + }, + { + "hex": "a4015820cdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd02a14269645770696E5F616273656E63652E6578616D706C652E636F6D03a262696458201D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D646e616d65644164616d0481a263616c672664747970656a7075626C69632D6B6579", + "cbor": "{1: h'CDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCD', 2: {\"id\": \"pin_absence.example.com\"}, 3: {\"id\": h'1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D', \"name\": \"Adam\"}, 4: [{\"alg\": -7, \"type\": \"public-key\"}]}", + "description": "make credential parameter 1" + }, + { + "hex": "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", + "cbor": "{1: h'687134968222EC17202E42505F8ED2B16AE22F16BB05B88C25DB9E602645F141', 2: {\"id\": \"make_bad_types.example.com\", \"icon\": \"http://icon.png\", \"name\": \"example\"}, 3: {\"id\": h'1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D', \"icon\": \"http://icon.png\", \"name\": \"John Doe\", \"displayName\": \"JD\"}, 4: [{\"alg\": -7, \"type\": \"public-key\"}], 5: [{\"id\": h'', \"type\": \"public-key\"}], 6: {}, 7: {\"rk\": false, \"up\": true, \"uv\": false}, 8: h'610C58506C864A708E26DD0CCF4BE3D9', 9: 1}", + "description": "make credential parameters 2" + }, + { + "hex": "a9015820cdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd02a3626964781a6d616b655f6261645f74797065732e6578616d706c652e636f6d6469636f6e6f687474703a2f2f69636f6e2e706e67646e616d65646A6F686E03a462696458201d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d1d6469636f6e6f687474703a2f2f69636f6e2e706e67646e616d65684a6f686e20446f656b646973706c61794e616d65624a440481a263616c672664747970656a7075626c69632d6b65790581a26269644064747970656a7075626c69632d6b657906a007a362726bf4627570f5627576f40850610c58506c864a708e26dd0ccf4be3d90901", + "cbor": "{1: h'CDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCD', 2: {\"id\": \"make_bad_types.example.com\", \"icon\": \"http://icon.png\", \"name\": \"john\"}, 3: {\"id\": h'1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D1D', \"icon\": \"http://icon.png\", \"name\": \"John Doe\", \"displayName\": \"JD\"}, 4: [{\"alg\": -7, \"type\": \"public-key\"}], 5: [{\"id\": h'', \"type\": \"public-key\"}], 6: {}, 7: {\"rk\": false, \"up\": true, \"uv\": false}, 8: h'610C58506C864A708E26DD0CCF4BE3D9', 9: 1}", + "description": "make credential parameters 3" + }, + { + "hex": "a5015820687134968222ec17202e42505f8ed2b16ae22f16bb05b88c25db9e602645f14102a26269646b6578616d706c652e636f6d646e616d656441636d6503a462696458203082019330820138a0030201023082019330820138a0030201023082019330826469636f6e782b68747470733a2f2f706963732e6578616d706c652e636f6d2f30302f702f61426a6a6a707150622e706e67646e616d65766a6f686e70736d697468406578616d706c652e636f6d6b646973706c61794e616d656d4a6f686e20502e20536d6974680482a263616c672664747970656a7075626C69632D6B6579a263616c6739010064747970656a7075626C69632D6B657907a162726bf5", + "cbor": "{1: h'687134968222EC17202E42505F8ED2B16AE22F16BB05B88C25DB9E602645F141', 2: {\"id\": \"example.com\", \"name\": \"Acme\"}, 3: {\"id\": h'3082019330820138A0030201023082019330820138A003020102308201933082', \"icon\": \"https://pics.example.com/00/p/aBjjjpqPb.png\", \"name\": \"johnpsmith@example.com\", \"displayName\": \"John P. Smith\"}, 4: [{\"alg\": -7, \"type\": \"public-key\"}, {\"alg\": -257, \"type\": \"public-key\"}], 7: {\"rk\": true}}", + "description": "make credential parameters 4 (ex 4)" + }, + { + "hex": "a301667061636b65640258f49d04bd8a43be42e45b38aee975ed4ff0b525e745051ac08014260bc12c86e7dd4100000000e00f21f9fc624cf200000000000000000070a148e03e8a315920691cead2a56117675a35857539dc16b51cc12a3acb525baeb124377f38026c29bf42f5b840285c1cf4b81783f3279f224b52dbff40523df87cc2a391a3ab888356002a5c7478385c9cc74fd0aea2a721247fb9023b3e4f6b080c59ebf62f2faa8345693dcb481932a50102032620012158202e3deacb152877fccbdc3bb03694178ba1c48fdd3943d49701c30a65144405202258204cdb1d0b76685e2652dfec4b5558e7e6dbf093dac0139919f9e14de98d0825cd03a263616c67266373696758453043022034870247c8292052f01ed3be4eccd22bb0ebb0344affce83733e2ac978f0d48b021f7f955405cb09b60f005c1c243f492865e2ca70871aeb35c7791365430ad4bd", + "cbor": "{1: \"packed\", 2: h'9D04BD8A43BE42E45B38AEE975ED4FF0B525E745051AC08014260BC12C86E7DD4100000000E00F21F9FC624CF200000000000000000070A148E03E8A315920691CEAD2A56117675A35857539DC16B51CC12A3ACB525BAEB124377F38026C29BF42F5B840285C1CF4B81783F3279F224B52DBFF40523DF87CC2A391A3AB888356002A5C7478385C9CC74FD0AEA2A721247FB9023B3E4F6B080C59EBF62F2FAA8345693DCB481932A50102032620012158202E3DEACB152877FCCBDC3BB03694178BA1C48FDD3943D49701C30A65144405202258204CDB1D0B76685E2652DFEC4B5558E7E6DBF093DAC0139919F9E14DE98D0825CD', 3: {\"alg\": -7, \"sig\": h'3043022034870247C8292052F01ED3BE4ECCD22BB0EBB0344AFFCE83733E2AC978F0D48B021F7F955405CB09B60F005C1C243F492865E2CA70871AEB35C7791365430AD4BD'}}", + "description": "get assertion parameters 1" + }, + { + "hex": "a70178196765745f6261645f74797065732e6578616d706c652e636f6d025820cdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd0381a262696458701c0746a765e28acf5305ed91025263648e4b95fe94b19ecc63fa01e2a5b83a933755ca8d7e4c460c6cca9be1bba428c8b3079920e4f5bf4abd327abeb0bc731fedd34f7fe15ad2e45290945122d38f9b1462618a186abd66209aebb8886fad71ae1e83429b628b096b7f2db0c157c00e64747970656a7075626c69632d6b657904a005a2627570f4627576f40650610c58506c864a708e26dd0ccf4be3d90701", + "cbor": "{1: \"get_bad_types.example.com\", 2: h'CDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCD', 3: [{\"id\": h'1C0746A765E28ACF5305ED91025263648E4B95FE94B19ECC63FA01E2A5B83A933755CA8D7E4C460C6CCA9BE1BBA428C8B3079920E4F5BF4ABD327ABEB0BC731FEDD34F7FE15AD2E45290945122D38F9B1462618A186ABD66209AEBB8886FAD71AE1E83429B628B096B7F2DB0C157C00E', \"type\": \"public-key\"}], 4: {}, 5: {\"up\": false, \"uv\": false}, 6: h'610C58506C864A708E26DD0CCF4BE3D9', 7: 1}", + "description": "get assertion parameters 2" + }, + { + "hex": "a70178196765745f6261645f74797065732e6578616d706c652e636f6d025820cdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd0381a262696458701c0746a765e28acf5305ed91025263648e4b95fe94b19ecc63fa01e2a5b83a933755ca8d7e4c460c6cca9be1bba428c8b3079920e4f5bf4abd327abeb0bc731fedd34f7fe15ad2e45290945122d38f9b1462618a186abd66209aebb8886fad71ae1e83429b628b096b7f2db0c157c00e64747970656a7075626c69632d6b657904a00650610c58506c864a708e26dd0ccf4be3d90701", + "cbor": "{1: \"get_bad_types.example.com\", 2: h'CDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCDCD', 3: [{\"id\": h'1C0746A765E28ACF5305ED91025263648E4B95FE94B19ECC63FA01E2A5B83A933755CA8D7E4C460C6CCA9BE1BBA428C8B3079920E4F5BF4ABD327ABEB0BC731FEDD34F7FE15AD2E45290945122D38F9B1462618A186ABD66209AEBB8886FAD71AE1E83429B628B096B7F2DB0C157C00E', \"type\": \"public-key\"}], 4: {},6: h'610C58506C864A708E26DD0CCF4BE3D9', 7: 1}", + "description": "get assertion parameters 3 (no key 5)" + }, + { + "hex": "a4016b6578616d706c652e636f6d025820687134968222ec17202e42505f8ed2b1687134968222ec17202e42505f8ed2b10382a26269645840f22006de4f905af68a43942f024f2a5ece603d9c6d4b3df8be08ed01fc442646d034858ac75bed3fd580bf9808d94fcbee82b9b2ef6677af0adcc35852ea6b9e64747970656a7075626C69632D6B6579a26269645832030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030364747970656a7075626C69632D6B657905a1627576f5", + "cbor": "{1: \"example.com\", 2: h'687134968222EC17202E42505F8ED2B1687134968222EC17202E42505F8ED2B1', 3: [{\"id\": h'F22006DE4F905AF68A43942F024F2A5ECE603D9C6D4B3DF8BE08ED01FC442646D034858AC75BED3FD580BF9808D94FCBEE82B9B2EF6677AF0ADCC35852EA6B9E', \"type\": \"public-key\"}, {\"id\": h'0303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303', \"type\": \"public-key\"}], 5: {\"uv\": true}}", + "description": "get assertion parameters 4 (ex 5)" + }, + { + "hex": "a201010202", + "cbor": "{1: 1, 2: 2}", + "description": "client pin parameters 1 (only key 1,2)" + }, + { + "hex": "a50101020303a501020338182001215820b20717fbc7c82517f511027d9e80888abd33a1837ce835a50ceffd4dea14337b2258209d132823edd852dcc21e4923168df96fe69ea591e1c2d13e98e4920673ec31b004400540", + "cbor": "{1: 1, 2: 3, 3: {1: 2, 3: -25, -1: 1, -2: h'B20717FBC7C82517F511027D9E80888ABD33A1837CE835A50CEFFD4DEA14337B', -3: h'9D132823EDD852DCC21E4923168DF96FE69EA591E1C2D13E98E4920673EC31B0'}, 4: h'', 5: h''}", + "description": "client pin parameters 2" + }, + { + "hex": "a50101020303a50102033818200121582060a086e3e9d1d95618826e706000a66b0809fadd29fbc50bb430d1fd21512f89225820c7d8411433be1e2728a397c66cca8d8b36b738cda54ee027d5efaf72c0db050a04504518a1ba83801245c6f8cad90952cda5055840a9eed54033b9f8fad7f76c69c8469f69c2e623ccb7819a31520b4da7756fc9bd1d4d4fc8d82df3284e9b3f600f03e994c6492a75fc2ed660a33ad343917aa7e2", + "cbor": "{1: 1, 2: 3, 3: {1: 2, 3: -25, -1: 1, -2: h'60A086E3E9D1D95618826E706000A66B0809FADD29FBC50BB430D1FD21512F89', -3: h'C7D8411433BE1E2728A397C66CCA8D8B36B738CDA54EE027D5EFAF72C0DB050A'}, 4: h'4518A1BA83801245C6F8CAD90952CDA5', 5: h'A9EED54033B9F8FAD7F76C69C8469F69C2E623CCB7819A31520B4DA7756FC9BD1D4D4FC8D82DF3284E9B3F600F03E994C6492A75FC2ED660A33AD343917AA7E2'}", + "description": "client pin parameters 3" + }, + { + "hex": "a40101020503a50102033818200121582060a086e3e9d1d95618826e706000a66b0809fadd29fbc50bb430d1fd21512f89225820c7d8411433be1e2728a397c66cca8d8b36b738cda54ee027d5efaf72c0db050a06509cac212d435c7f03d0ffa29caedf0e35", + "cbor": "{1: 1, 2: 5, 3: {1: 2, 3: -25, -1: 1, -2: h'60A086E3E9D1D95618826E706000A66B0809FADD29FBC50BB430D1FD21512F89', -3: h'C7D8411433BE1E2728A397C66CCA8D8B36B738CDA54EE027D5EFAF72C0DB050A'}, 6: h'9CAC212D435C7F03D0FFA29CAEDF0E35'}", + "description": "client pin parameters 4" + } +] diff --git a/fuzz/make_corpus.py b/fuzz/make_corpus.py new file mode 100644 index 0000000..11c8575 --- /dev/null +++ b/fuzz/make_corpus.py @@ -0,0 +1,60 @@ +import argparse +import json +import os.path + +# Creates a directory containing seed inputs from a json file having +# the following structure: +# [ +# { +# "hex": "a901a1182a182a02a3626964781a6d616b655f6261645f7...", +# "cbor": "{1: h'42', 2: {\"id\": \"make.example.com\", ...", +# "description": "make credential parameters" +# }, +# ... +# ] +# +# Usage: +# - pass the resulting corpus directory path as the first argument +# - pass the json file path to make the corpus from as the second argument +# Example: +# python make_corpus.py ./corpus ./corpus_file.json + + +# Creates a corpus directory to the given path from the given json file. +def make_corpus(corpus_dir, corpus_json): + if not os.path.exists(corpus_dir): + os.makedirs(corpus_dir) + elif not os.path.isdir(corpus_dir): + raise NotADirectoryError + + if os.path.isfile(corpus_json) and \ + os.path.splitext(corpus_json)[-1] == ".json": + with open(corpus_json) as corpus_file: + corpus = json.load(corpus_file) + else: + raise TypeError + + for i, seed_file in enumerate(corpus): + seed_file_name = "seed_file_" + str(i) + raw_hex = seed_file["hex"].decode("hex") + with open(os.path.join(corpus_dir, seed_file_name), "wb") as f: + f.write(raw_hex) + + +def main(): + parser = argparse.ArgumentParser() + parser.add_argument( + "corpus_directory", help="the resulting corpus directory path") + parser.add_argument( + "corpus_json", help="the json file path to make the corpus from") + args = parser.parse_args() + try: + make_corpus(args.corpus_directory, args.corpus_json) + except NotADirectoryError: + print(args.corpus_directory, " is not a directory.\n") + except TypeError: + print(args.corpus_json, " must be a json file.\n") + + +if __name__ == "__main__": + main() diff --git a/libraries/persistent_store/src/bitfield.rs b/libraries/persistent_store/src/bitfield.rs index a2760c2..09e0ad7 100644 --- a/libraries/persistent_store/src/bitfield.rs +++ b/libraries/persistent_store/src/bitfield.rs @@ -13,8 +13,6 @@ // limitations under the License. //! Helps manipulate bit fields in 32-bits words. -// TODO(ia0): Remove when the module is used. -#![cfg_attr(not(test), allow(dead_code, unused_macros))] use crate::{StoreError, StoreResult}; @@ -180,24 +178,29 @@ macro_rules! bitfield_impl { // - Input are bit field descriptors // - Position is the number of bits used by prior bit fields // - Output are the bit field definitions - ([$($output: tt)*]{ pos: $pos: expr }[$name: ident: Bit, $($input: tt)*]) => { + ([$($output: tt)*]{ pos: $pos: expr } + [$(#[$meta: meta])* $name: ident: Bit, $($input: tt)*]) => { bitfield_impl! { - [$($output)* const $name: Bit = Bit { pos: $pos };] + [$($output)* $(#[$meta])* const $name: Bit = Bit { pos: $pos };] { pos: $pos + 1 } [$($input)*] } }; - ([$($output: tt)*]{ pos: $pos: expr }[$name: ident: Field <= $max: expr, $($input: tt)*]) => { + ([$($output: tt)*]{ pos: $pos: expr } + [$(#[$meta: meta])* $name: ident: Field <= $max: expr, $($input: tt)*]) => { bitfield_impl! { - [$($output)* const $name: Field = Field { pos: $pos, len: num_bits($max) };] + [$($output)* $(#[$meta])* const $name: Field = Field { + pos: $pos, + len: num_bits($max), + };] { pos: $pos + $name.len } [$($input)*] } }; ([$($output: tt)*]{ pos: $pos: expr } - [$name: ident: Checksum <= $max: expr, $($input: tt)*]) => { + [$(#[$meta: meta])* $name: ident: Checksum <= $max: expr, $($input: tt)*]) => { bitfield_impl! { - [$($output)* const $name: Checksum = Checksum { + [$($output)* $(#[$meta])* const $name: Checksum = Checksum { field: Field { pos: $pos, len: num_bits($max) } };] { pos: $pos + $name.field.len } @@ -213,9 +216,9 @@ macro_rules! bitfield_impl { } }; ([$($output: tt)*]{ pos: $pos: expr } - [$name: ident: ConstField = $bits: tt, $($input: tt)*]) => { + [$(#[$meta: meta])* $name: ident: ConstField = $bits: tt, $($input: tt)*]) => { bitfield_impl! { - Reverse $name []$bits + Reverse $(#[$meta])* $name []$bits [$($output)*]{ pos: $pos }[$($input)*] } }; @@ -224,17 +227,17 @@ macro_rules! bitfield_impl { // Auxiliary rules for constant bit fields: // - Input is a sequence of bits // - Output is the reversed sequence of bits - (Reverse $name: ident [$($output_bits: tt)*] [$bit: tt $($input_bits: tt)*] + (Reverse $(#[$meta: meta])* $name: ident [$($output_bits: tt)*] [$bit: tt $($input_bits: tt)*] [$($output: tt)*]{ pos: $pos: expr }[$($input: tt)*]) => { bitfield_impl! { - Reverse $name [$bit $($output_bits)*][$($input_bits)*] + Reverse $(#[$meta])* $name [$bit $($output_bits)*][$($input_bits)*] [$($output)*]{ pos: $pos }[$($input)*] } }; - (Reverse $name: ident $bits: tt [] + (Reverse $(#[$meta: meta])* $name: ident $bits: tt [] [$($output: tt)*]{ pos: $pos: expr }[$($input: tt)*]) => { bitfield_impl! { - ConstField $name { len: 0, val: 0 }$bits + ConstField $(#[$meta])* $name { len: 0, val: 0 }$bits [$($output)*]{ pos: $pos }[$($input)*] } }; @@ -242,10 +245,10 @@ macro_rules! bitfield_impl { // Auxiliary rules for constant bit fields: // - Input is a sequence of bits in reversed order // - Output is the constant bit field definition with the sequence of bits as value - (ConstField $name: ident { len: $len: expr, val: $val: expr }[] + (ConstField $(#[$meta: meta])* $name: ident { len: $len: expr, val: $val: expr }[] [$($output: tt)*]{ pos: $pos: expr }[$($input: tt)*]) => { bitfield_impl! { - [$($output)* const $name: ConstField = ConstField { + [$($output)* $(#[$meta])* const $name: ConstField = ConstField { field: Field { pos: $pos, len: $len }, value: $val, };] @@ -253,10 +256,10 @@ macro_rules! bitfield_impl { [$($input)*] } }; - (ConstField $name: ident { len: $len: expr, val: $val: expr }[$bit: tt $($bits: tt)*] - [$($output: tt)*]{ pos: $pos: expr }[$($input: tt)*]) => { + (ConstField $(#[$meta: meta])* $name: ident { len: $len: expr, val: $val: expr } + [$bit: tt $($bits: tt)*][$($output: tt)*]{ pos: $pos: expr }[$($input: tt)*]) => { bitfield_impl! { - ConstField $name { len: $len + 1, val: $val * 2 + $bit }[$($bits)*] + ConstField $(#[$meta])* $name { len: $len + 1, val: $val * 2 + $bit }[$($bits)*] [$($output)*]{ pos: $pos }[$($input)*] } }; diff --git a/libraries/persistent_store/src/buffer.rs b/libraries/persistent_store/src/buffer.rs new file mode 100644 index 0000000..0059826 --- /dev/null +++ b/libraries/persistent_store/src/buffer.rs @@ -0,0 +1,683 @@ +// Copyright 2019-2020 Google LLC +// +// 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. + +use crate::{Storage, StorageError, StorageIndex, StorageResult}; +use alloc::borrow::Borrow; +use alloc::boxed::Box; +use alloc::vec; + +/// Simulates a flash storage using a buffer in memory. +/// +/// This buffer storage can be used in place of an actual flash storage. It is particularly useful +/// for tests and fuzzing, for which it has dedicated functionalities. +/// +/// This storage tracks how many times words are written between page erase cycles, how many times +/// pages are erased, and whether an operation flips bits in the wrong direction (optional). +/// Operations panic if those conditions are broken. This storage also permits to interrupt +/// operations for inspection or to corrupt the operation. +#[derive(Clone)] +pub struct BufferStorage { + /// Content of the storage. + storage: Box<[u8]>, + + /// Options of the storage. + options: BufferOptions, + + /// Number of times a word was written since the last time its page was erased. + word_writes: Box<[usize]>, + + /// Number of times a page was erased. + page_erases: Box<[usize]>, + + /// Interruption state. + interruption: Interruption, +} + +/// Options of a buffer storage. +#[derive(Clone, Debug)] +pub struct BufferOptions { + /// Size of a word in bytes. + pub word_size: usize, + + /// Size of a page in bytes. + pub page_size: usize, + + /// How many times a word can be written between page erase cycles. + pub max_word_writes: usize, + + /// How many times a page can be erased. + pub max_page_erases: usize, + + /// Whether bits cannot be written from 0 to 1. + pub strict_write: bool, +} + +/// Corrupts a slice given actual and expected value. +/// +/// A corruption function is called exactly once and takes 2 arguments: +/// - A mutable slice representing the storage before the interrupted operation. +/// - A shared slice representing what the storage would have been if the operation was not +/// interrupted. +/// +/// The corruption function may flip an arbitrary number of bits in the mutable slice, but may only +/// flip bits that differ between both slices. +pub type BufferCorruptFunction<'a> = Box; + +impl BufferStorage { + /// Creates a buffer storage. + /// + /// # Panics + /// + /// The following preconditions must hold: + /// - `options.word_size` must be a power of two. + /// - `options.page_size` must be a power of two. + /// - `options.page_size` must be word-aligned. + /// - `storage.len()` must be page-aligned. + pub fn new(storage: Box<[u8]>, options: BufferOptions) -> BufferStorage { + assert!(options.word_size.is_power_of_two()); + assert!(options.page_size.is_power_of_two()); + let num_words = storage.len() / options.word_size; + let num_pages = storage.len() / options.page_size; + let buffer = BufferStorage { + storage, + options, + word_writes: vec![0; num_words].into_boxed_slice(), + page_erases: vec![0; num_pages].into_boxed_slice(), + interruption: Interruption::Ready, + }; + assert!(buffer.is_word_aligned(buffer.options.page_size)); + assert!(buffer.is_page_aligned(buffer.storage.len())); + buffer + } + + /// Arms an interruption after a given delay. + /// + /// Before each subsequent mutable operation (write or erase), the delay is decremented if + /// positive. If the delay is elapsed, the operation is saved and an error is returned. + /// Subsequent operations will panic until the interrupted operation is [corrupted] or the + /// interruption is [reset]. + /// + /// # Panics + /// + /// Panics if an interruption is already armed. + /// + /// [corrupted]: struct.BufferStorage.html#method.corrupt_operation + /// [reset]: struct.BufferStorage.html#method.reset_interruption + pub fn arm_interruption(&mut self, delay: usize) { + self.interruption.arm(delay); + } + + /// Disarms an interruption that did not trigger. + /// + /// Returns the remaining delay. + /// + /// # Panics + /// + /// Panics if any of the following conditions hold: + /// - An interruption was not [armed]. + /// - An interruption was armed and it has triggered. + /// + /// [armed]: struct.BufferStorage.html#method.arm_interruption + pub fn disarm_interruption(&mut self) -> usize { + self.interruption.get().err().unwrap() + } + + /// Resets an interruption regardless of triggering. + /// + /// # Panics + /// + /// Panics if an interruption was not [armed]. + /// + /// [armed]: struct.BufferStorage.html#method.arm_interruption + pub fn reset_interruption(&mut self) { + let _ = self.interruption.get(); + } + + /// Corrupts an interrupted operation. + /// + /// Applies the [corruption function] to the storage. Counters are updated accordingly: + /// - If a word is fully written, its counter is incremented regardless of whether other words + /// of the same operation have been fully written. + /// - If a page is fully erased, its counter is incremented (and its word counters are reset). + /// + /// # Panics + /// + /// Panics if any of the following conditions hold: + /// - An interruption was not [armed]. + /// - An interruption was armed but did not trigger. + /// - The corruption function corrupts more bits than allowed. + /// - The interrupted operation itself would have panicked. + /// + /// [armed]: struct.BufferStorage.html#method.arm_interruption + /// [corruption function]: type.BufferCorruptFunction.html + pub fn corrupt_operation(&mut self, corrupt: BufferCorruptFunction) { + let operation = self.interruption.get().unwrap(); + let range = self.operation_range(&operation).unwrap(); + let mut before = self.storage[range.clone()].to_vec().into_boxed_slice(); + match operation { + BufferOperation::Write { value: after, .. } => { + corrupt(&mut before, &after); + self.incr_word_writes(range.start, &before, &after); + } + BufferOperation::Erase { page } => { + let after = vec![0xff; self.page_size()].into_boxed_slice(); + corrupt(&mut before, &after); + if before == after { + self.incr_page_erases(page); + } + } + }; + self.storage[range].copy_from_slice(&before); + } + + /// Returns the number of times a word was written. + pub fn get_word_writes(&self, word: usize) -> usize { + self.word_writes[word] + } + + /// Returns the number of times a page was erased. + pub fn get_page_erases(&self, page: usize) -> usize { + self.page_erases[page] + } + + /// Sets the number of times a page was erased. + pub fn set_page_erases(&mut self, page: usize, cycle: usize) { + self.page_erases[page] = cycle; + } + + /// Returns whether a number is word-aligned. + fn is_word_aligned(&self, x: usize) -> bool { + x & (self.options.word_size - 1) == 0 + } + + /// Returns whether a number is page-aligned. + fn is_page_aligned(&self, x: usize) -> bool { + x & (self.options.page_size - 1) == 0 + } + + /// Updates the counters as if a page was erased. + /// + /// The page counter of that page is incremented and the word counters of that page are reset. + /// + /// # Panics + /// + /// Panics if the maximum number of erase cycles per page is reached. + fn incr_page_erases(&mut self, page: usize) { + assert!(self.page_erases[page] < self.max_page_erases()); + self.page_erases[page] += 1; + let num_words = self.page_size() / self.word_size(); + for word in 0..num_words { + self.word_writes[page * num_words + word] = 0; + } + } + + /// Updates the word counters as if a partial write occurred. + /// + /// The partial write is described as if `complete` was supposed to be written to the storage + /// starting at byte `index`, but actually only `value` was written. Word counters are + /// incremented only if their value would change and they would be completely written. + /// + /// # Preconditions + /// + /// - `index` must be word-aligned. + /// - `value` and `complete` must have the same word-aligned length. + /// + /// # Panics + /// + /// Panics if the maximum number of writes per word is reached. + fn incr_word_writes(&mut self, index: usize, value: &[u8], complete: &[u8]) { + let word_size = self.word_size(); + for i in 0..value.len() / word_size { + let range = core::ops::Range { + start: i * word_size, + end: (i + 1) * word_size, + }; + // Partial word writes do not count. + if value[range.clone()] != complete[range.clone()] { + continue; + } + // Words are written only if necessary. + if value[range.clone()] == self.storage[index..][range] { + continue; + } + let word = index / word_size + i; + assert!(self.word_writes[word] < self.max_word_writes()); + self.word_writes[word] += 1; + } + } + + /// Returns the storage range of an operation. + fn operation_range( + &self, + operation: &BufferOperation>, + ) -> StorageResult> { + match *operation { + BufferOperation::Write { index, ref value } => index.range(value.borrow().len(), self), + BufferOperation::Erase { page } => { + StorageIndex { page, byte: 0 }.range(self.page_size(), self) + } + } + } +} + +impl Storage for BufferStorage { + fn word_size(&self) -> usize { + self.options.word_size + } + + fn page_size(&self) -> usize { + self.options.page_size + } + + fn num_pages(&self) -> usize { + self.storage.len() / self.options.page_size + } + + fn max_word_writes(&self) -> usize { + self.options.max_word_writes + } + + fn max_page_erases(&self) -> usize { + self.options.max_page_erases + } + + fn read_slice(&self, index: StorageIndex, length: usize) -> StorageResult<&[u8]> { + Ok(&self.storage[index.range(length, self)?]) + } + + fn write_slice(&mut self, index: StorageIndex, value: &[u8]) -> StorageResult<()> { + if !self.is_word_aligned(index.byte) || !self.is_word_aligned(value.len()) { + return Err(StorageError::NotAligned); + } + let operation = BufferOperation::Write { index, value }; + let range = self.operation_range(&operation)?; + // Interrupt operation if armed and delay expired. + self.interruption.tick(&operation)?; + // Check and update counters. + self.incr_word_writes(range.start, value, value); + // Check strict write. + if self.options.strict_write { + for (byte, &val) in range.clone().zip(value.iter()) { + assert_eq!(self.storage[byte] & val, val); + } + } + // Write to the storage. + self.storage[range].copy_from_slice(value); + Ok(()) + } + + fn erase_page(&mut self, page: usize) -> StorageResult<()> { + let operation = BufferOperation::Erase { page }; + let range = self.operation_range(&operation)?; + // Interrupt operation if armed and delay expired. + self.interruption.tick(&operation)?; + // Check and update counters. + self.incr_page_erases(page); + // Write to the storage. + for byte in &mut self.storage[range] { + *byte = 0xff; + } + Ok(()) + } +} + +impl core::fmt::Display for BufferStorage { + fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> { + let num_pages = self.num_pages(); + let num_words = self.page_size() / self.word_size(); + let num_bytes = self.word_size(); + for page in 0..num_pages { + write!(f, "[{}]", self.page_erases[page])?; + for word in 0..num_words { + write!(f, " [{}]", self.word_writes[page * num_words + word])?; + for byte in 0..num_bytes { + let index = (page * num_words + word) * num_bytes + byte; + write!(f, "{:02x}", self.storage[index])?; + } + } + writeln!(f)?; + } + Ok(()) + } +} + +/// Represents a storage operation. +/// +/// It is polymorphic over the ownership of the byte slice to avoid unnecessary copies. +#[derive(Clone, Debug, PartialEq, Eq)] +enum BufferOperation> { + /// Represents a write operation. + Write { + /// The storage index at which the write should occur. + index: StorageIndex, + + /// The slice that should be written. + value: ByteSlice, + }, + + /// Represents an erase operation. + Erase { + /// The page that should be erased. + page: usize, + }, +} + +/// Represents a storage operation owning its byte slices. +type OwnedBufferOperation = BufferOperation>; + +/// Represents a storage operation sharing its byte slices. +type SharedBufferOperation<'a> = BufferOperation<&'a [u8]>; + +impl<'a> SharedBufferOperation<'a> { + fn to_owned(&self) -> OwnedBufferOperation { + match *self { + BufferOperation::Write { index, value } => BufferOperation::Write { + index, + value: value.to_vec().into_boxed_slice(), + }, + BufferOperation::Erase { page } => BufferOperation::Erase { page }, + } + } +} + +/// Controls when an operation is interrupted. +/// +/// This can be used to simulate power-offs while the device is writing to the storage or erasing a +/// page in the storage. +#[derive(Clone)] +enum Interruption { + /// Mutable operations have normal behavior. + Ready, + + /// If the delay is positive, mutable operations decrement it. If the count is zero, mutable + /// operations fail and are saved. + Armed { delay: usize }, + + /// Mutable operations panic. + Saved { operation: OwnedBufferOperation }, +} + +impl Interruption { + /// Arms an interruption for a given delay. + /// + /// # Panics + /// + /// Panics if an interruption is already armed. + fn arm(&mut self, delay: usize) { + match self { + Interruption::Ready => *self = Interruption::Armed { delay }, + _ => panic!(), + } + } + + /// Disarms an interruption. + /// + /// Returns the interrupted operation if any, otherwise the remaining delay. + /// + /// # Panics + /// + /// Panics if an interruption was not armed. + fn get(&mut self) -> Result { + let mut interruption = Interruption::Ready; + core::mem::swap(self, &mut interruption); + match interruption { + Interruption::Armed { delay } => Err(delay), + Interruption::Saved { operation } => Ok(operation), + _ => panic!(), + } + } + + /// Interrupts an operation if the delay is over. + /// + /// Decrements the delay if positive. Otherwise, the operation is stored and an error is + /// returned to interrupt the operation. + /// + /// # Panics + /// + /// Panics if an operation has already been interrupted and the interruption has not been + /// disarmed. + fn tick(&mut self, operation: &SharedBufferOperation) -> StorageResult<()> { + match self { + Interruption::Ready => (), + Interruption::Armed { delay } if *delay == 0 => { + let operation = operation.to_owned(); + *self = Interruption::Saved { operation }; + return Err(StorageError::CustomError); + } + Interruption::Armed { delay } => *delay -= 1, + Interruption::Saved { .. } => panic!(), + } + Ok(()) + } +} + +#[cfg(test)] +mod tests { + use super::*; + + const NUM_PAGES: usize = 2; + const OPTIONS: BufferOptions = BufferOptions { + word_size: 4, + page_size: 16, + max_word_writes: 2, + max_page_erases: 3, + strict_write: true, + }; + // Those words are decreasing bit patterns. Bits are only changed from 1 to 0 and at least one + // bit is changed. + const BLANK_WORD: &[u8] = &[0xff, 0xff, 0xff, 0xff]; + const FIRST_WORD: &[u8] = &[0xee, 0xdd, 0xbb, 0x77]; + const SECOND_WORD: &[u8] = &[0xca, 0xc9, 0xa9, 0x65]; + const THIRD_WORD: &[u8] = &[0x88, 0x88, 0x88, 0x44]; + + fn new_storage() -> Box<[u8]> { + vec![0xff; NUM_PAGES * OPTIONS.page_size].into_boxed_slice() + } + + #[test] + fn words_are_decreasing() { + fn assert_is_decreasing(prev: &[u8], next: &[u8]) { + for (&prev, &next) in prev.iter().zip(next.iter()) { + assert_eq!(prev & next, next); + assert!(prev != next); + } + } + assert_is_decreasing(BLANK_WORD, FIRST_WORD); + assert_is_decreasing(FIRST_WORD, SECOND_WORD); + assert_is_decreasing(SECOND_WORD, THIRD_WORD); + } + + #[test] + fn options_ok() { + let buffer = BufferStorage::new(new_storage(), OPTIONS); + assert_eq!(buffer.word_size(), OPTIONS.word_size); + assert_eq!(buffer.page_size(), OPTIONS.page_size); + assert_eq!(buffer.num_pages(), NUM_PAGES); + assert_eq!(buffer.max_word_writes(), OPTIONS.max_word_writes); + assert_eq!(buffer.max_page_erases(), OPTIONS.max_page_erases); + } + + #[test] + fn read_write_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 0 }; + let next_index = StorageIndex { page: 0, byte: 4 }; + assert_eq!(buffer.read_slice(index, 4).unwrap(), BLANK_WORD); + buffer.write_slice(index, FIRST_WORD).unwrap(); + assert_eq!(buffer.read_slice(index, 4).unwrap(), FIRST_WORD); + assert_eq!(buffer.read_slice(next_index, 4).unwrap(), BLANK_WORD); + } + + #[test] + fn erase_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 0 }; + let other_index = StorageIndex { page: 1, byte: 0 }; + buffer.write_slice(index, FIRST_WORD).unwrap(); + buffer.write_slice(other_index, FIRST_WORD).unwrap(); + assert_eq!(buffer.read_slice(index, 4).unwrap(), FIRST_WORD); + assert_eq!(buffer.read_slice(other_index, 4).unwrap(), FIRST_WORD); + buffer.erase_page(0).unwrap(); + assert_eq!(buffer.read_slice(index, 4).unwrap(), BLANK_WORD); + assert_eq!(buffer.read_slice(other_index, 4).unwrap(), FIRST_WORD); + } + + #[test] + fn invalid_range() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 12 }; + let half_index = StorageIndex { page: 0, byte: 14 }; + let over_index = StorageIndex { page: 0, byte: 16 }; + let bad_page = StorageIndex { page: 2, byte: 0 }; + + // Reading a word in the storage is ok. + assert!(buffer.read_slice(index, 4).is_ok()); + // Reading a half-word in the storage is ok. + assert!(buffer.read_slice(half_index, 2).is_ok()); + // Reading even a single byte outside a page is not ok. + assert!(buffer.read_slice(over_index, 1).is_err()); + // But reading an empty slice just after a page is ok. + assert!(buffer.read_slice(over_index, 0).is_ok()); + // Reading even an empty slice outside the storage is not ok. + assert!(buffer.read_slice(bad_page, 0).is_err()); + + // Writing a word in the storage is ok. + assert!(buffer.write_slice(index, FIRST_WORD).is_ok()); + // Writing an unaligned word is not ok. + assert!(buffer.write_slice(half_index, FIRST_WORD).is_err()); + // Writing a word outside a page is not ok. + assert!(buffer.write_slice(over_index, FIRST_WORD).is_err()); + // But writing an empty slice just after a page is ok. + assert!(buffer.write_slice(over_index, &[]).is_ok()); + // Writing even an empty slice outside the storage is not ok. + assert!(buffer.write_slice(bad_page, &[]).is_err()); + + // Only pages in the storage can be erased. + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(2).is_err()); + } + + #[test] + fn write_twice_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 4 }; + assert!(buffer.write_slice(index, FIRST_WORD).is_ok()); + assert!(buffer.write_slice(index, SECOND_WORD).is_ok()); + } + + #[test] + fn write_twice_and_once_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 0 }; + let next_index = StorageIndex { page: 0, byte: 4 }; + assert!(buffer.write_slice(index, FIRST_WORD).is_ok()); + assert!(buffer.write_slice(index, SECOND_WORD).is_ok()); + assert!(buffer.write_slice(next_index, THIRD_WORD).is_ok()); + } + + #[test] + #[should_panic] + fn write_three_times_panics() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 4 }; + assert!(buffer.write_slice(index, FIRST_WORD).is_ok()); + assert!(buffer.write_slice(index, SECOND_WORD).is_ok()); + let _ = buffer.write_slice(index, THIRD_WORD); + } + + #[test] + fn write_twice_then_once_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 0 }; + assert!(buffer.write_slice(index, FIRST_WORD).is_ok()); + assert!(buffer.write_slice(index, SECOND_WORD).is_ok()); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.write_slice(index, FIRST_WORD).is_ok()); + } + + #[test] + fn erase_three_times_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(0).is_ok()); + } + + #[test] + fn erase_three_times_and_once_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(1).is_ok()); + } + + #[test] + #[should_panic] + fn erase_four_times_panics() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(0).is_ok()); + assert!(buffer.erase_page(0).is_ok()); + let _ = buffer.erase_page(0).is_ok(); + } + + #[test] + #[should_panic] + fn switch_zero_to_one_panics() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + let index = StorageIndex { page: 0, byte: 0 }; + assert!(buffer.write_slice(index, SECOND_WORD).is_ok()); + let _ = buffer.write_slice(index, FIRST_WORD); + } + + #[test] + fn interrupt_delay_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + + // Interrupt the second operation. + buffer.arm_interruption(1); + + // The first operation should not fail. + buffer + .write_slice(StorageIndex { page: 0, byte: 0 }, &[0x5c; 8]) + .unwrap(); + // The delay should be decremented. + assert_eq!(buffer.disarm_interruption(), 0); + // The storage should have been modified. + assert_eq!(&buffer.storage[..8], &[0x5c; 8]); + assert!(buffer.storage[8..].iter().all(|&x| x == 0xff)); + } + + #[test] + fn interrupt_save_ok() { + let mut buffer = BufferStorage::new(new_storage(), OPTIONS); + + // Interrupt the second operation. + buffer.arm_interruption(1); + + // The second operation should fail. + buffer + .write_slice(StorageIndex { page: 0, byte: 0 }, &[0x5c; 8]) + .unwrap(); + assert!(buffer + .write_slice(StorageIndex { page: 0, byte: 8 }, &[0x93; 8]) + .is_err()); + // The operation should represent the change. + buffer.corrupt_operation(Box::new(|_, value| assert_eq!(value, &[0x93; 8]))); + // The storage should not have been modified. + assert_eq!(&buffer.storage[..8], &[0x5c; 8]); + assert!(buffer.storage[8..].iter().all(|&x| x == 0xff)); + } +} diff --git a/libraries/persistent_store/src/format.rs b/libraries/persistent_store/src/format.rs new file mode 100644 index 0000000..1fa6521 --- /dev/null +++ b/libraries/persistent_store/src/format.rs @@ -0,0 +1,957 @@ +// Copyright 2019-2020 Google LLC +// +// 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. + +// TODO(ia0): Remove when the module is used. +#![allow(dead_code)] + +use crate::bitfield::*; +use crate::{Storage, StorageIndex, StoreError, StoreResult}; +use alloc::vec::Vec; +use core::cmp::min; + +type WORD = u32; + +/// Size of a word in bytes. +/// +/// Currently, the store only supports storages where a word is 4 bytes. +const WORD_SIZE: usize = core::mem::size_of::(); + +/// Minimum number of words per page. +/// +/// Currently, the store only supports storages where pages have at least 8 words. +const MIN_NUM_WORDS_PER_PAGE: usize = 8; + +/// Maximum size of a page in bytes. +/// +/// Currently, the store only supports storages where pages are between 8 and 1024 [words]. +/// +/// [words]: constant.WORD_SIZE.html +const MAX_PAGE_SIZE: usize = 4096; + +/// Maximum number of erase cycles. +/// +/// Currently, the store only supports storages where the maximum number of erase cycles fits on 16 +/// bits. +const MAX_ERASE_CYCLE: usize = 65535; + +/// Minimum number of pages. +/// +/// Currently, the store only supports storages with at least 3 pages. +const MIN_NUM_PAGES: usize = 3; + +/// Maximum page index. +/// +/// Thus the maximum number of pages is one more than this number. Currently, the store only +/// supports storages where the number of pages is between 3 and 64. +const MAX_PAGE_INDEX: usize = 63; + +/// Maximum key index. +/// +/// Thus the number of keys is one more than this number. Currently, the store only supports 4096 +/// keys. +const MAX_KEY_INDEX: usize = 4095; + +/// Maximum length in bytes of a user payload. +/// +/// Currently, the store only supports values smaller than 1024 bytes. +const MAX_VALUE_LEN: usize = 1023; + +/// Maximum number of updates per transaction. +/// +/// Currently, the store only supports transactions with at most 31 updates. +const MAX_UPDATES: usize = 31; + +/// Maximum number of words per virtual page. +const MAX_VIRT_PAGE_SIZE: usize = div_ceil(MAX_PAGE_SIZE, WORD_SIZE) - CONTENT_WORD; + +/// Word with all bits set to one. +const ERASED_WORD: WORD = !(0 as WORD); + +/// Helpers for a given storage configuration. +#[derive(Clone, Debug)] +pub struct Format { + /// The size in bytes of a page in the storage. + /// + /// # Invariant + /// + /// - Words divide a page evenly. + /// - There are at least 8 words in a page. + /// - There are at most `MAX_PAGE_SIZE` bytes in a page. + page_size: usize, + + /// The number of pages in the storage. + /// + /// # Invariant + /// + /// - There are at least 3 pages. + /// - There are at most `MAX_PAGE_INDEX + 1` pages. + num_pages: usize, + + /// The maximum number of times a page can be erased. + /// + /// # Invariant + /// + /// - A page can be erased at most `MAX_ERASE_CYCLE` times. + max_page_erases: usize, +} + +impl Format { + /// Extracts the format from a storage. + /// + /// Returns `None` if the storage is not [supported]. + /// + /// [supported]: struct.Format.html#method.is_storage_supported + pub fn new(storage: &S) -> Option { + if Format::is_storage_supported(storage) { + Some(Format { + page_size: storage.page_size(), + num_pages: storage.num_pages(), + max_page_erases: storage.max_page_erases(), + }) + } else { + None + } + } + + /// Returns whether a storage is supported. + /// + /// A storage is supported if the following conditions hold: + /// - The size of a word is [`WORD_SIZE`] bytes. + /// - The size of a word evenly divides the size of a page. + /// - A page contains at least [`MIN_NUM_WORDS_PER_PAGE`] words. + /// - A page contains at most [`MAX_PAGE_SIZE`] bytes. + /// - There are at least [`MIN_NUM_PAGES`] pages. + /// - There are at most [`MAX_PAGE_INDEX`]` + 1` pages. + /// - A word can be written at least twice between erase cycles. + /// - The maximum number of erase cycles is at most [`MAX_ERASE_CYCLE`]. + /// + /// [`WORD_SIZE`]: constant.WORD_SIZE.html + /// [`MIN_NUM_WORDS_PER_PAGE`]: constant.MIN_NUM_WORDS_PER_PAGE.html + /// [`MAX_PAGE_SIZE`]: constant.MAX_PAGE_SIZE.html + /// [`MIN_NUM_PAGES`]: constant.MIN_NUM_PAGES.html + /// [`MAX_PAGE_INDEX`]: constant.MAX_PAGE_INDEX.html + /// [`MAX_ERASE_CYCLE`]: constant.MAX_ERASE_CYCLE.html + fn is_storage_supported(storage: &S) -> bool { + let word_size = storage.word_size(); + let page_size = storage.page_size(); + let num_pages = storage.num_pages(); + let max_word_writes = storage.max_word_writes(); + let max_page_erases = storage.max_page_erases(); + word_size == WORD_SIZE + && page_size % word_size == 0 + && (MIN_NUM_WORDS_PER_PAGE * word_size <= page_size && page_size <= MAX_PAGE_SIZE) + && (MIN_NUM_PAGES <= num_pages && num_pages <= MAX_PAGE_INDEX + 1) + && max_word_writes >= 2 + && max_page_erases <= MAX_ERASE_CYCLE + } + + /// The size of a word in bytes. + pub fn word_size(&self) -> usize { + WORD_SIZE + } + + /// The size of a page in bytes. + /// + /// We have `MIN_NUM_WORDS_PER_PAGE * self.word_size() <= self.page_size() <= MAX_PAGE_SIZE`. + pub fn page_size(&self) -> usize { + self.page_size + } + + /// The number of pages in the storage, denoted by `N`. + /// + /// We have `MIN_NUM_PAGES <= N <= MAX_PAGE_INDEX + 1`. + pub fn num_pages(&self) -> usize { + self.num_pages + } + + /// The maximum page index. + /// + /// We have `2 <= self.max_page() <= MAX_PAGE_INDEX`. + pub fn max_page(&self) -> usize { + self.num_pages - 1 + } + + /// The maximum number of times a page can be erased, denoted by `E`. + /// + /// We have `E <= MAX_ERASE_CYCLE`. + pub fn max_page_erases(&self) -> usize { + self.max_page_erases + } + + /// The maximum key. + pub fn max_key(&self) -> usize { + MAX_KEY_INDEX + } + + /// The maximum number of updates per transaction. + pub fn max_updates(&self) -> usize { + MAX_UPDATES + } + + /// The size of a virtual page in words, denoted by `Q`. + /// + /// A virtual page is stored in a physical page after the page header. + /// + /// We have `MIN_NUM_WORDS_PER_PAGE - 2 <= Q <= MAX_VIRT_PAGE_SIZE`. + pub fn virt_page_size(&self) -> usize { + self.page_size() / self.word_size() - CONTENT_WORD + } + + /// The maximum length in bytes of a user payload. + /// + /// We have `(MIN_NUM_WORDS_PER_PAGE - 3) * self.word_size() <= self.max_value_len() <= + /// MAX_VALUE_LEN`. + pub fn max_value_len(&self) -> usize { + min( + (self.virt_page_size() - 1) * self.word_size(), + MAX_VALUE_LEN, + ) + } + + /// The maximum prefix length in words, denoted by `M`. + /// + /// A prefix is the first words of a virtual page that belong to the last entry of the previous + /// virtual page. This happens because entries may overlap up to 2 virtual pages. + /// + /// We have `MIN_NUM_WORDS_PER_PAGE - 3 <= M < Q`. + pub fn max_prefix_len(&self) -> usize { + self.bytes_to_words(self.max_value_len()) + } + + /// The total virtual capacity in words, denoted by `V`. + /// + /// We have `V = (N - 1) * (Q - 1) - M`. + /// + /// We can show `V >= (N - 2) * (Q - 1)` with the following steps: + /// - `M <= Q - 1` from `M < Q` from [`M`] definition + /// - `-M >= -(Q - 1)` from above + /// - `V >= (N - 1) * (Q - 1) - (Q - 1)` from `V` definition + /// + /// [`M`]: struct.Format.html#method.max_prefix_len + pub fn virt_size(&self) -> usize { + (self.num_pages() - 1) * (self.virt_page_size() - 1) - self.max_prefix_len() + } + + /// The total user capacity in words, denoted by `C`. + /// + /// We have `C = V - N = (N - 1) * (Q - 2) - M - 1`. + /// + /// We can show `C >= (N - 2) * (Q - 2) - 2` with the following steps: + /// - `V >= (N - 2) * (Q - 1)` from [`V`] definition + /// - `C >= (N - 2) * (Q - 1) - N` from `C` definition + /// - `(N - 2) * (Q - 1) - N = (N - 2) * (Q - 2) - 2` by calculus + /// + /// [`V`]: struct.Format.html#method.virt_size + pub fn total_capacity(&self) -> usize { + // From the virtual capacity, we reserve N - 1 words for `Erase` entries and 1 word for a + // `Clear` entry. + self.virt_size() - self.num_pages() + } + + /// The total virtual lifetime in words, denoted by `L`. + /// + /// We have `L = (E * N + N - 1) * Q`. + pub fn total_lifetime(&self) -> Position { + Position::new(self, self.max_page_erases(), self.num_pages() - 1, 0) + } + + /// Returns the word position of the first entry of a page. + /// + /// The init info of the page must be provided to know where the first entry of the page + /// starts. + pub fn page_head(&self, init: InitInfo, page: usize) -> Position { + Position::new(self, init.cycle, page, init.prefix) + } + + /// Returns the storage index of the init info of a page. + pub fn index_init(&self, page: usize) -> StorageIndex { + let byte = INIT_WORD * self.word_size(); + StorageIndex { page, byte } + } + + /// Parses the init info of a page from its storage representation. + pub fn parse_init(&self, word: WORD) -> StoreResult> { + Ok(if word == ERASED_WORD { + WordState::Erased + } else if WORD_CHECKSUM.get(word)? != 0 { + WordState::Partial + } else { + let cycle = INIT_CYCLE.get(word); + let prefix = INIT_PREFIX.get(word); + if cycle > self.max_page_erases() || prefix > self.max_prefix_len() { + return Err(StoreError::InvalidStorage); + } + WordState::Valid(InitInfo { cycle, prefix }) + }) + } + + /// Builds the storage representation of an init info. + pub fn build_init(&self, init: InitInfo) -> [u8; WORD_SIZE] { + let mut word = ERASED_WORD; + INIT_CYCLE.set(&mut word, init.cycle); + INIT_PREFIX.set(&mut word, init.prefix); + WORD_CHECKSUM.set(&mut word, 0); + word.to_ne_bytes() + } + + /// Returns the storage index of the compact info of a page. + pub fn index_compact(&self, page: usize) -> StorageIndex { + let byte = COMPACT_WORD * self.word_size(); + StorageIndex { page, byte } + } + + /// Parses the compact info of a page from its storage representation. + pub fn parse_compact(&self, word: WORD) -> StoreResult> { + Ok(if word == ERASED_WORD { + WordState::Erased + } else if WORD_CHECKSUM.get(word)? != 0 { + WordState::Partial + } else { + let tail = COMPACT_TAIL.get(word); + if tail > self.virt_size() + self.max_prefix_len() { + return Err(StoreError::InvalidStorage); + } + WordState::Valid(CompactInfo { tail }) + }) + } + + /// Builds the storage representation of a compact info. + pub fn build_compact(&self, compact: CompactInfo) -> [u8; WORD_SIZE] { + let mut word = ERASED_WORD; + COMPACT_TAIL.set(&mut word, compact.tail); + WORD_CHECKSUM.set(&mut word, 0); + word.to_ne_bytes() + } + + /// Builds the storage representation of an internal entry. + pub fn build_internal(&self, internal: InternalEntry) -> [u8; WORD_SIZE] { + let mut word = ERASED_WORD; + match internal { + InternalEntry::Erase { page } => { + ID_ERASE.set(&mut word); + ERASE_PAGE.set(&mut word, page); + } + InternalEntry::Clear { min_key } => { + ID_CLEAR.set(&mut word); + CLEAR_MIN_KEY.set(&mut word, min_key); + } + InternalEntry::Marker { count } => { + ID_MARKER.set(&mut word); + MARKER_COUNT.set(&mut word, count); + } + InternalEntry::Remove { key } => { + ID_REMOVE.set(&mut word); + REMOVE_KEY.set(&mut word, key); + } + } + WORD_CHECKSUM.set(&mut word, 0); + word.to_ne_bytes() + } + + /// Parses the first word of an entry from its storage representation. + pub fn parse_word(&self, word: WORD) -> StoreResult> { + let valid = if ID_PADDING.check(word) { + ParsedWord::Padding(Padding { length: 0 }) + } else if ID_HEADER.check(word) { + if HEADER_DELETED.get(word) { + let length = HEADER_LENGTH.get(word); + if length > self.max_value_len() { + return Err(StoreError::InvalidStorage); + } + let length = self.bytes_to_words(length); + ParsedWord::Padding(Padding { length }) + } else { + let flipped = HEADER_FLIPPED.get(word); + let length = HEADER_LENGTH.get(word); + let key = HEADER_KEY.get(word); + let checksum = HEADER_CHECKSUM.get(word)?; + ParsedWord::Header(Header { + flipped, + length, + key, + checksum, + }) + } + } else if ID_ERASE.check(word) { + let page = ERASE_PAGE.get(word); + ParsedWord::Internal(InternalEntry::Erase { page }) + } else if ID_CLEAR.check(word) { + let min_key = CLEAR_MIN_KEY.get(word); + ParsedWord::Internal(InternalEntry::Clear { min_key }) + } else if ID_MARKER.check(word) { + let count = MARKER_COUNT.get(word); + ParsedWord::Internal(InternalEntry::Marker { count }) + } else if ID_REMOVE.check(word) { + let key = REMOVE_KEY.get(word); + ParsedWord::Internal(InternalEntry::Remove { key }) + } else if word == ERASED_WORD { + return Ok(WordState::Erased); + } else { + return Ok(WordState::Partial); + }; + if let ParsedWord::Internal(internal) = &valid { + if WORD_CHECKSUM.get(word)? != 0 { + return Ok(WordState::Partial); + } + let invalid = match internal { + InternalEntry::Erase { page } => *page > self.max_page(), + InternalEntry::Clear { min_key } => *min_key > self.max_key(), + InternalEntry::Marker { count } => *count > MAX_UPDATES, + InternalEntry::Remove { key } => *key > self.max_key(), + }; + if invalid { + return Err(StoreError::InvalidStorage); + } + } + Ok(WordState::Valid(valid)) + } + + /// Builds the storage representation of a user entry. + pub fn build_user(&self, key: usize, value: &[u8]) -> Vec { + let length = value.len(); + let word_size = self.word_size(); + let footer = self.bytes_to_words(length); + let mut result = vec![0xff; (1 + footer) * word_size]; + result[word_size..][..length].copy_from_slice(value); + let mut word = ERASED_WORD; + ID_HEADER.set(&mut word); + if footer > 0 && is_erased(&result[footer * word_size..]) { + HEADER_FLIPPED.set(&mut word); + *result.last_mut().unwrap() = 0x7f; + } + HEADER_LENGTH.set(&mut word, length); + HEADER_KEY.set(&mut word, key); + HEADER_CHECKSUM.set(&mut word, count_zeros(&result[footer * word_size..])); + result[..word_size].copy_from_slice(&word.to_ne_bytes()); + result + } + + /// Sets the padding bit in the first word of a user entry. + pub fn set_padding(&self, word: &mut WORD) { + ID_PADDING.set(word); + } + + /// Sets the deleted bit in the first word of a user entry. + pub fn set_deleted(&self, word: &mut WORD) { + HEADER_DELETED.set(word); + } + + /// Returns the minimum number of words to represent a given number of bytes. + /// + /// # Preconditions + /// + /// - `bytes + self.word_size()` does not overflow. + pub fn bytes_to_words(&self, bytes: usize) -> usize { + div_ceil(bytes, self.word_size()) + } +} + +/// The word index of the init info in a page. +const INIT_WORD: usize = 0; + +/// The word index of the compact info in a page. +const COMPACT_WORD: usize = 1; + +/// The word index of the content of a page. +/// +/// Since a page is at least 8 words, there is always at least 6 words of content. +const CONTENT_WORD: usize = 2; + +/// The checksum for a single word. +/// +/// Since checksums are the number of bits set to zero and a word is 32 bits, we need 5 bits to +/// store numbers between 0 and 27 (which is 32 - 5). +const WORD_CHECKSUM: Checksum = Checksum { + field: Field { pos: 27, len: 5 }, +}; + +// The fields of the init info of a page. +bitfield! { + /// The number of times the page has been erased. + INIT_CYCLE: Field <= MAX_ERASE_CYCLE, + + /// The word index of the first entry in this virtual page. + INIT_PREFIX: Field <= div_ceil(MAX_VALUE_LEN, WORD_SIZE), + + #[cfg(test)] + LEN_INIT: Length, +} + +// The fields of the compact info of a page. +bitfield! { + /// The distance in words between head and tail at compaction. + /// + /// In particular, compaction copies non-deleted user entries from the head to the tail as long + /// as entries span the page to be compacted. + COMPACT_TAIL: Field <= MAX_VIRT_PAGE_SIZE * MAX_PAGE_INDEX, + + #[cfg(test)] + LEN_COMPACT: Length, +} + +// Overview of the first word of the different kind of entries. +// +// Each column represents a bit of the word. The first 2 lines give the position in hexadecimal of +// the bit in the word (the exponent of 2 when the word is written in binary). Each entry starts +// with the sequence of bits of its identifier. The dots following the identifier are the number of +// bits necessary to hold the information of the entry (including the checksum). The remaining free +// bits after the dots are not used by the entry. +// +// 0 1 +// 0123456789abcdef0123456789abcdef +// padding 0 +// header 10.............................. +// erase 11000........... +// clear 11001................. +// marker 11010.......... +// remove 11011................. +// +// NOTE: We could pad the internal entries to the right by extending their identifier. This permits +// to free some space for shorter identifier for future kind of entries. + +// The fields of a padding entry. +bitfield! { + /// The identifier for padding entries. + ID_PADDING: ConstField = [0], +} + +// The fields of a user entry. +bitfield! { + /// The identifier for user entries. + ID_HEADER: ConstField = [1 0], + + /// Whether the user entry is deleted. + HEADER_DELETED: Bit, + + /// Whether the last bit of the user data is flipped. + HEADER_FLIPPED: Bit, + + /// The length in bytes of the user data. + // NOTE: It is possible to support values of length 1024 by having a separate kind of entries + // when the value is empty. We could then subtract one from the length here. + HEADER_LENGTH: Field <= MAX_VALUE_LEN, + + /// The key of the user entry. + HEADER_KEY: Field <= MAX_KEY_INDEX, + + /// The checksum of the user entry. + /// + /// This counts the number of bits set to zero in both the first and last words of the user + /// entry, except in the checksum itself. So it needs 6 bits to store numbers between 0 and 58. + // NOTE: It may be possible to save one bit by storing: + // - the footer checksum (as a field) if the value is not empty + // - the header checksum (as a checksum) if the value is empty + HEADER_CHECKSUM: Checksum <= 58, + + #[cfg(test)] + LEN_HEADER: Length, +} + +// The fields of an erase entry. +bitfield! { + /// The identifier for erase entries. + ID_ERASE: ConstField = [1 1 0 0 0], + + /// The page to be erased. + ERASE_PAGE: Field <= MAX_PAGE_INDEX, + + #[cfg(test)] + LEN_ERASE: Length, +} + +// The fields of a clear entry. +bitfield! { + /// The identifier for clear entries. + ID_CLEAR: ConstField = [1 1 0 0 1], + + /// The minimum key to be cleared. + /// + /// All entries with a key below this limit are not cleared. All other entries are deleted. + CLEAR_MIN_KEY: Field <= MAX_KEY_INDEX, + + #[cfg(test)] + LEN_CLEAR: Length, +} + +// The fields of a marker entry. +bitfield! { + /// The identifier for marker entries. + ID_MARKER: ConstField = [1 1 0 1 0], + + /// The number of updates in this transaction. + /// + /// The update entries follow this marker entry. + MARKER_COUNT: Field <= MAX_UPDATES, + + #[cfg(test)] + LEN_MARKER: Length, +} + +// The fields of a remove entry. +bitfield! { + /// The identifier for remove entries. + ID_REMOVE: ConstField = [1 1 0 1 1], + + /// The key of the user entry to be removed. + REMOVE_KEY: Field <= MAX_KEY_INDEX, + + #[cfg(test)] + LEN_REMOVE: Length, +} + +/// The position of a word in the virtual storage. +/// +/// With the notations defined in `Format`, let: +/// - `w` a virtual word offset in a page which is between `0` and `Q - 1` +/// - `p` a page offset which is between `0` and `N - 1` +/// - `c` the number of erase cycles of a page which is between `0` and `E` +/// +/// Then the position of a word is `(c*N + p)*Q + w`. This position monotonically increases and +/// represents the consumed lifetime of the storage. +#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)] +pub struct Position(usize); + +impl core::ops::Add for Position { + type Output = Position; + + fn add(self, delta: usize) -> Position { + Position(self.0 + delta) + } +} + +impl core::ops::Sub for Position { + type Output = usize; + + fn sub(self, base: Position) -> usize { + self.0 - base.0 + } +} + +impl core::ops::AddAssign for Position { + fn add_assign(&mut self, delta: usize) { + self.0 += delta; + } +} + +impl Position { + /// Create a word position given its coordinates. + /// + /// The coordinates of a word are: + /// - Its word index in its page. + /// - Its page index in the storage. + /// - The number of times that page was erased. + pub fn new(format: &Format, cycle: usize, page: usize, word: usize) -> Position { + Position((cycle * format.num_pages() + page) * format.virt_page_size() + word) + } + + /// Accesses the underlying position as a natural number. + pub fn get(self) -> usize { + self.0 + } + + /// Returns the associated storage index. + pub fn index(self, format: &Format) -> StorageIndex { + let page = self.page(format); + let word = CONTENT_WORD + self.word(format); + let byte = word * format.word_size(); + StorageIndex { page, byte } + } + + /// Returns the beginning of the current virtual page. + pub fn page_begin(self, format: &Format) -> Position { + let virt_page_size = format.virt_page_size(); + Position((self.0 / virt_page_size) * virt_page_size) + } + + /// Returns the beginning of the next virtual page. + pub fn next_page(self, format: &Format) -> Position { + let virt_page_size = format.virt_page_size(); + Position((self.0 / virt_page_size + 1) * virt_page_size) + } + + /// Returns the number of times the current page was erased. + pub fn cycle(self, format: &Format) -> usize { + (self.0 / format.virt_page_size()) / format.num_pages() + } + + /// Returns the current page index. + pub fn page(self, format: &Format) -> usize { + (self.0 / format.virt_page_size()) % format.num_pages() + } + + /// Returns the current word index in the page. + pub fn word(self, format: &Format) -> usize { + self.0 % format.virt_page_size() + } +} + +/// Possible states of some storage representation as a word. +pub enum WordState { + /// The word is still erased. + Erased, + + /// The word is partially written. + Partial, + + /// Holds the decoded version of a valid word. + Valid(T), +} + +/// Information for an initialized page. +pub struct InitInfo { + /// The number of times this page has been erased. + pub cycle: usize, + + /// The word index of the first entry in this virtual page. + pub prefix: usize, +} + +/// Information for a page being compacted. +pub struct CompactInfo { + /// The distance in words between head and tail at compaction. + pub tail: usize, +} + +/// The first word of an entry. +#[derive(Debug)] +pub enum ParsedWord { + /// Padding entry. + Padding(Padding), + + /// Header of a user entry. + Header(Header), + + /// Internal entry. + Internal(InternalEntry), +} + +/// Padding entry. +#[derive(Debug)] +pub struct Padding { + /// The number of following padding words after the first word of the padding entry. + pub length: usize, +} + +/// Header of a user entry. +#[derive(Debug)] +pub struct Header { + /// Whether the last bit of the user data is flipped. + pub flipped: bool, + + /// The length in bytes of the user data. + pub length: usize, + + /// The key of the user entry. + pub key: usize, + + /// The checksum of the user entry. + pub checksum: usize, +} + +impl Header { + /// Checks the validity of a user entry. + /// + /// If the user entry has no payload, the `footer` must be set to `None`. Otherwise it should be + /// the last word of the entry. + pub fn check(&self, footer: Option<&[u8]>) -> bool { + footer.map_or(0, count_zeros) == self.checksum + } +} + +/// Internal entry. +#[derive(Debug)] +pub enum InternalEntry { + /// Indicates that a page should be erased. + Erase { + /// The page to be erased. + page: usize, + }, + + /// Indicates that user entries with high key should be deleted. + Clear { + /// The minimum key a user entry should have to be deleted. + min_key: usize, + }, + + /// Marks the start of a transaction. + /// + /// The marker is followed by a given number of updates, which are either user entries or remove + /// entries. + Marker { + /// The number of updates in the transaction. + count: usize, + }, + + /// Indicates that a user entry should be removed. + /// + /// This is only useful (and valid) as part of a transaction, since removing a single entry is + /// already atomic. + Remove { + /// The key of the user entry to be removed. + key: usize, + }, +} + +/// Returns whether a slice has all bits equal to one. +pub fn is_erased(slice: &[u8]) -> bool { + slice.iter().all(|&x| x == 0xff) +} + +/// Divides then takes ceiling. +/// +/// Returns `ceil(x / m)` in mathematical notations (not Rust code). +/// +/// # Preconditions +/// +/// - `x + m` does not overflow. +const fn div_ceil(x: usize, m: usize) -> usize { + (x + m - 1) / m +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn size_of_format() { + assert_eq!(std::mem::size_of::(), 24); + } + + #[test] + fn checksum_ok() { + let Field { pos, len } = WORD_CHECKSUM.field; + // There is enough bits to represents the number of zeros preceding the checksum. + assert_eq!(len, num_bits(pos)); + // The checksum is the last field of a word. + assert_eq!(pos + len, 8 * WORD_SIZE); + // The data of words using the checksum don't overlap the checksum. + let words = &[ + &LEN_INIT, + &LEN_COMPACT, + &LEN_ERASE, + &LEN_CLEAR, + &LEN_MARKER, + &LEN_REMOVE, + ]; + for word in words { + assert!(word.pos < pos); + } + } + + #[test] + fn init_ok() { + assert_eq!(INIT_CYCLE.pos, 0); + assert_eq!(INIT_CYCLE.len, 16); + assert_eq!(INIT_PREFIX.pos, 16); + assert_eq!(INIT_PREFIX.len, 9); + assert_eq!(LEN_INIT.pos, 25); + } + + #[test] + fn compact_ok() { + assert_eq!(COMPACT_TAIL.pos, 0); + assert_eq!(COMPACT_TAIL.len, 16); + assert_eq!(LEN_COMPACT.pos, 16); + } + + #[test] + fn header_ok() { + assert_eq!(ID_HEADER.field.pos, 0); + assert_eq!(ID_HEADER.field.len, 2); + assert_eq!(ID_HEADER.value, 0b01); + assert_eq!(HEADER_DELETED.pos, 2); + assert_eq!(HEADER_FLIPPED.pos, 3); + assert_eq!(HEADER_LENGTH.pos, 4); + assert_eq!(HEADER_LENGTH.len, 10); + assert_eq!(HEADER_KEY.pos, 14); + assert_eq!(HEADER_KEY.len, 12); + assert_eq!(HEADER_CHECKSUM.field.pos, 26); + assert_eq!(HEADER_CHECKSUM.field.len, 6); + assert_eq!(LEN_HEADER.pos, 32); + } + + #[test] + fn erase_ok() { + assert_eq!(ID_ERASE.field.pos, 0); + assert_eq!(ID_ERASE.field.len, 5); + assert_eq!(ID_ERASE.value, 0b00011); + assert_eq!(ERASE_PAGE.pos, 5); + assert_eq!(ERASE_PAGE.len, 6); + assert_eq!(LEN_ERASE.pos, 11); + } + + #[test] + fn clear_ok() { + assert_eq!(ID_CLEAR.field.pos, 0); + assert_eq!(ID_CLEAR.field.len, 5); + assert_eq!(ID_CLEAR.value, 0b10011); + assert_eq!(CLEAR_MIN_KEY.pos, 5); + assert_eq!(CLEAR_MIN_KEY.len, 12); + assert_eq!(LEN_CLEAR.pos, 17); + } + + #[test] + fn marker_ok() { + assert_eq!(ID_MARKER.field.pos, 0); + assert_eq!(ID_MARKER.field.len, 5); + assert_eq!(ID_MARKER.value, 0b01011); + assert_eq!(MARKER_COUNT.pos, 5); + assert_eq!(MARKER_COUNT.len, 5); + assert_eq!(LEN_MARKER.pos, 10); + } + + #[test] + fn remove_ok() { + assert_eq!(ID_REMOVE.field.pos, 0); + assert_eq!(ID_REMOVE.field.len, 5); + assert_eq!(ID_REMOVE.value, 0b11011); + assert_eq!(REMOVE_KEY.pos, 5); + assert_eq!(REMOVE_KEY.len, 12); + assert_eq!(LEN_REMOVE.pos, 17); + } + + #[test] + fn is_erased_ok() { + assert!(is_erased(&[])); + assert!(is_erased(&[0xff])); + assert!(is_erased(&[0xff, 0xff])); + assert!(!is_erased(&[0x00])); + assert!(!is_erased(&[0xff, 0xfe])); + assert!(!is_erased(&[0x7f, 0xff])); + } + + #[test] + fn div_ceil_ok() { + assert_eq!(div_ceil(0, 1), 0); + assert_eq!(div_ceil(1, 1), 1); + assert_eq!(div_ceil(2, 1), 2); + assert_eq!(div_ceil(0, 2), 0); + assert_eq!(div_ceil(1, 2), 1); + assert_eq!(div_ceil(2, 2), 1); + assert_eq!(div_ceil(3, 2), 2); + } + + #[test] + fn positions_fit_in_a_word() { + // All reachable positions are smaller than this value, which is one past the last position. + // It is simply the total number of virtual words, i.e. the number of words per virtual page + // times the number of virtual pages times the number of times a virtual page can be used + // (one more than the number of times it can be erased since we can write before the first + // erase cycle and after the last erase cycle). + assert_eq!( + (MAX_ERASE_CYCLE + 1) * (MAX_PAGE_INDEX + 1) * MAX_VIRT_PAGE_SIZE, + 0xff800000 + ); + } +} diff --git a/libraries/persistent_store/src/lib.rs b/libraries/persistent_store/src/lib.rs index 954e66f..f1c1653 100644 --- a/libraries/persistent_store/src/lib.rs +++ b/libraries/persistent_store/src/lib.rs @@ -12,12 +12,353 @@ // See the License for the specific language governing permissions and // limitations under the License. +// TODO(ia0): Add links once the code is complete. +//! Store abstraction for flash storage +//! +//! # Specification +//! +//! The store provides a partial function from keys to values on top of a storage +//! interface. The store total capacity depends on the size of the storage. Store +//! updates may be bundled in transactions. Mutable operations are atomic, including +//! when interrupted. +//! +//! The store is flash-efficient in the sense that it uses the storage lifetime +//! efficiently. For each page, all words are written at least once between erase +//! cycles and all erase cycles are used. However, not all written words are user +//! content: lifetime is also consumed with metadata and compaction. +//! +//! The store is extendable with other entries than key-values. It is essentially a +//! framework providing access to the storage lifetime. The partial function is +//! simply the most common usage and can be used to encode other usages. +//! +//! ## Definitions +//! +//! An _entry_ is a pair of a key and a value. A _key_ is a number between 0 +//! and 4095. A _value_ is a byte slice with a length between 0 and 1023 bytes (for +//! large enough pages). +//! +//! The store provides the following _updates_: +//! - Given a key and a value, `Insert` updates the store such that the value is +//! associated with the key. The values for other keys are left unchanged. +//! - Given a key, `Remove` updates the store such that no value is associated with +//! the key. The values for other keys are left unchanged. Additionally, if there +//! was a value associated with the key, the value is wiped from the storage +//! (all its bits are set to 0). +//! +//! The store provides the following _read-only operations_: +//! - `Iter` iterates through the store returning all entries exactly once. The +//! iteration order is not specified but stable between mutable operations. +//! - `Capacity` returns how many words can be stored before the store is full. +//! - `Lifetime` returns how many words can be written before the storage lifetime +//! is consumed. +//! +//! The store provides the following _mutable operations_: +//! - Given a set of independent updates, `Transaction` applies the sequence of +//! updates. +//! - Given a threshold, `Clear` removes all entries with a key greater or equal +//! to the threshold. +//! - Given a length in words, `Prepare` makes one step of compaction unless that +//! many words can be written without compaction. This operation has no effect +//! on the store but may still mutate its storage. In particular, the store has +//! the same capacity but a possibly reduced lifetime. +//! +//! A mutable operation is _atomic_ if, when power is lost during the operation, the +//! store is either updated (as if the operation succeeded) or left unchanged (as if +//! the operation did not occur). If the store is left unchanged, lifetime may still +//! be consumed. +//! +//! The store relies on the following _storage interface_: +//! - It is possible to read a byte slice. The slice won't span multiple pages. +//! - It is possible to write a word slice. The slice won't span multiple pages. +//! - It is possible to erase a page. +//! - The pages are sequentially indexed from 0. If the actual underlying storage +//! is segmented, then the storage layer should translate those indices to +//! actual page addresses. +//! +//! The store has a _total capacity_ of `C = (N - 1) * (P - 4) - M - 1` words, where +//! `P` is the number of words per page, `N` is the number of pages, and `M` is the +//! maximum length in words of a value (256 for large enough pages). The capacity +//! used by each mutable operation is given below (a transient word only uses +//! capacity during the operation): +//! - `Insert` uses `1 + ceil(len / 4)` words where `len` is the length of the +//! value in bytes. If an entry was replaced, the words used by its insertion +//! are freed. +//! - `Remove` doesn't use capacity if alone in the transaction and 1 transient +//! word otherwise. If an entry was deleted, the words used by its insertion are +//! freed. +//! - `Transaction` uses 1 transient word. In addition, the updates of the +//! transaction use and free words as described above. +//! - `Clear` doesn't use capacity and frees the words used by the insertion of +//! the deleted entries. +//! - `Prepare` doesn't use capacity. +//! +//! The _total lifetime_ of the store is below `L = ((E + 1) * N - 1) * (P - 2)` and +//! above `L - M` words, where `E` is the maximum number of erase cycles. The +//! lifetime is used when capacity is used, including transiently, as well as when +//! compaction occurs. Compaction frequency and lifetime consumption are positively +//! correlated to the store load factor (the ratio of used capacity to total capacity). +//! +//! It is possible to approximate the cost of transient words in terms of capacity: +//! `L` transient words are equivalent to `C - x` words of capacity where `x` is the +//! average capacity (including transient) of operations. +//! +//! ## Preconditions +//! +//! The following assumptions need to hold, or the store may behave in unexpected ways: +//! - A word can be written twice between erase cycles. +//! - A page can be erased `E` times after the first boot of the store. +//! - When power is lost while writing a slice or erasing a page, the next read +//! returns a slice where a subset (possibly none or all) of the bits that +//! should have been modified have been modified. +//! - Reading a slice is deterministic. When power is lost while writing a slice +//! or erasing a slice (erasing a page containing that slice), reading that +//! slice repeatedly returns the same result (until it is overwritten or its +//! page is erased). +//! - To decide whether a page has been erased, it is enough to test if all its +//! bits are equal to 1. +//! - When power is lost while writing a slice or erasing a page, that operation +//! does not count towards the limits. However, completing that write or erase +//! operation would count towards the limits, as if the number of writes per +//! word and number of erase cycles could be fractional. +//! - The storage is only modified by the store. Note that completely erasing the +//! storage is supported, essentially losing all content and lifetime tracking. +//! It is preferred to use `Clear` with a threshold of 0 to keep the lifetime +//! tracking. +//! +//! The store properties may still hold outside some of those assumptions, but with +//! an increasing chance of failure. +//! +//! # Implementation +//! +//! We define the following constants: +//! - `E < 65536` the number of times a page can be erased. +//! - `3 <= N < 64` the number of pages in the storage. +//! - `8 <= P <= 1024` the number of words in a page. +//! - `Q = P - 2` the number of words in a virtual page. +//! - `K = 4096` the maximum number of keys. +//! - `M = min(Q - 1, 256)` the maximum length in words of a value. +//! - `V = (N - 1) * (Q - 1) - M` the virtual capacity. +//! - `C = V - N` the user capacity. +//! +//! We build a virtual storage from the physical storage using the first 2 words of +//! each page: +//! - The first word contains the number of times the page has been erased. +//! - The second word contains the starting word to which this page is being moved +//! during compaction. +//! +//! The virtual storage has a length of `(E + 1) * N * Q` words and represents the +//! lifetime of the store. (We reserve the last `Q + M` words to support adding +//! emergency lifetime.) This virtual storage has a linear address space. +//! +//! We define a set of overlapping windows of `N * Q` words at each `Q`-aligned +//! boundary. We call `i` the window spanning from `i * Q` to `(i + N) * Q`. Only +//! those windows actually exist in the underlying storage. We use compaction to +//! shift the current window from `i` to `i + 1`, preserving the content of the +//! store. +//! +//! For a given state of the virtual storage, we define `h_i` as the position of the +//! first entry of the window `i`. We call it the head of the window `i`. Because +//! entries are at most `M + 1` words, they can overlap on the next page only by `M` +//! words. So we have `i * Q <= h_i <= i * Q + M` . Since there are no entries +//! before the first page, we have `h_0 = 0`. +//! +//! We define `t_i` as one past the last entry of the window `i`. If there are no +//! entries in that window, we have `t_i = h_i`. We call `t_i` the tail of the +//! window `i`. We define the compaction invariant as `t_i - h_i <= V`. +//! +//! We define `|x|` as the capacity used before position `x`. We have `|x| <= x`. We +//! define the capacity invariant as `|t_i| - |h_i| <= C`. +//! +//! Using this virtual storage, entries are appended to the tail as long as there is +//! both virtual capacity to preserve the compaction invariant and capacity to +//! preserve the capacity invariant. When virtual capacity runs out, the first page +//! of the window is compacted and the window is shifted. +//! +//! Entries are identified by a prefix of bits. The prefix has to contain at least +//! one bit set to zero to differentiate from the tail. Entries can be one of: +//! - Padding: A word whose first bit is set to zero. The rest is arbitrary. This +//! entry is used to mark words partially written after an interrupted operation +//! as padding such that they are ignored by future operations. +//! - Header: A word whose second bit is set to zero. It contains the following fields: +//! - A bit indicating whether the entry is deleted. +//! - A bit indicating whether the value is word-aligned and has all bits set +//! to 1 in its last word. The last word of an entry is used to detect that +//! an entry has been fully written. As such it must contain at least one +//! bit equal to zero. +//! - The key of the entry. +//! - The length in bytes of the value. The value follows the header. The +//! entry is word-aligned if the value is not. +//! - The checksum of the first and last word of the entry. +//! - Erase: A word used during compaction. It contains the page to be erased and +//! a checksum. +//! - Clear: A word used during the `Clear` operation. It contains the threshold +//! and a checksum. +//! - Marker: A word used during the `Transaction` operation. It contains the +//! number of updates following the marker and a checksum. +//! - Remove: A word used during the `Transaction` operation. It contains the key +//! of the entry to be removed and a checksum. +//! +//! Checksums are the number of bits equal to 0. +//! +//! # Proofs +//! +//! ## Compaction +//! +//! It should always be possible to fully compact the store, after what the +//! remaining capacity should be available in the current window (restoring the +//! compaction invariant). We consider all notations on the virtual storage after +//! the full compaction. We will use the `|x|` notation although we update the state +//! of the virtual storage. This is fine because compaction doesn't change the +//! status of an existing word. +//! +//! We want to show that the next `N - 1` compactions won't move the tail past the +//! last page of their window, with `I` the initial window: +//! +//! ```text +//! forall 1 <= i <= N - 1, t_{I + i} <= (I + i + N - 1) * Q +//! ``` +//! +//! We assume `i` between `1` and `N - 1`. +//! +//! One step of compaction advances the tail by how many words were used in the +//! first page of the window with the last entry possibly overlapping on the next +//! page. +//! +//! ```text +//! forall j, t_{j + 1} = t_j + |h_{j + 1}| - |h_j| + 1 +//! ``` +//! +//! By induction, we have: +//! +//! ```text +//! t_{I + i} <= t_I + |h_{I + i}| - |h_I| + i +//! ``` +//! +//! We have the following properties: +//! +//! ```text +//! t_I <= h_I + V +//! |h_{I + i}| - |h_I| <= h_{I + i} - h_I +//! h_{I + i} <= (I + i) * Q + M +//! ``` +//! +//! Replacing into our previous equality, we can conclude: +//! +//! ```text +//! t_{I + i} = t_I + |h_{I + i}| - |h_I| + i +//! <= h_I + V + (I + i) * Q + M - h_I + i +//! = (N - 1) * (Q - 1) - M + (I + i) * Q + M + i +//! = (N - 1) * (Q - 1) + (I + i) * Q + i +//! = (I + i + N - 1) * Q + i - (N - 1) +//! <= (I + i + N - 1) * Q +//! ``` +//! +//! We also want to show that after `N - 1` compactions, the remaining capacity is +//! available without compaction. +//! +//! ```text +//! V - (t_{I + N - 1} - h_{I + N - 1}) >= // The available words in the window. +//! C - (|t_{I + N - 1}| - |h_{I + N - 1}|) // The remaining capacity. +//! + 1 // Reserved for Clear. +//! ``` +//! +//! We can replace the definition of `C` and simplify: +//! +//! ```text +//! V - (t_{I + N - 1} - h_{I + N - 1}) >= V - N - (|t_{I + N - 1}| - |h_{I + N - 1}|) + 1 +//! iff t_{I + N - 1} - h_{I + N - 1} <= |t_{I + N - 1}| - |h_{I + N - 1}| + N - 1 +//! ``` +//! +//! We have the following properties: +//! +//! ```text +//! t_{I + N - 1} = t_I + |h_{I + N - 1}| - |h_I| + N - 1 +//! |t_{I + N - 1}| - |h_{I + N - 1}| = |t_I| - |h_I| // Compaction preserves capacity. +//! |h_{I + N - 1}| - |t_I| <= h_{I + N - 1} - t_I +//! ``` +//! +//! From which we conclude: +//! +//! ```text +//! t_{I + N - 1} - h_{I + N - 1} <= |t_{I + N - 1}| - |h_{I + N - 1}| + N - 1 +//! iff t_I + |h_{I + N - 1}| - |h_I| + N - 1 - h_{I + N - 1} <= |t_I| - |h_I| + N - 1 +//! iff t_I + |h_{I + N - 1}| - h_{I + N - 1} <= |t_I| +//! iff |h_{I + N - 1}| - |t_I| <= h_{I + N - 1} - t_I +//! ``` +//! +//! +//! ## Checksum +//! +//! The main property we want is that all partially written/erased words are either +//! the initial word, the final word, or invalid. +//! +//! We say that a bit sequence `TARGET` is reachable from a bit sequence `SOURCE` if +//! both have the same length and `SOURCE & TARGET == TARGET` where `&` is the +//! bitwise AND operation on bit sequences of that length. In other words, when +//! `SOURCE` has a bit equal to 0 then `TARGET` also has that bit equal to 0. +//! +//! The only written entries start with `101` or `110` and are written from an +//! erased word. Marking an entry as padding or deleted is a single bit operation, +//! so the property trivially holds. For those cases, the proof relies on the fact +//! that there is exactly one bit equal to 0 in the 3 first bits. Either the 3 first +//! bits are still `111` in which case we expect the remaining bits to be equal +//! to 1. Otherwise we can use the checksum of the given type of entry because those +//! 2 types of entries are not reachable from each other. Here is a visualization of +//! the partitioning based on the first 3 bits: +//! +//! | First 3 bits | Description | How to check | +//! | ------------:| ------------------ | ---------------------------- | +//! | `111` | Erased word | All bits set to `1` | +//! | `101` | User entry | Contains a checksum | +//! | `110` | Internal entry | Contains a checksum | +//! | `100` | Deleted user entry | No check, atomically written | +//! | `0??` | Padding entry | No check, atomically written | +//! +//! To show that valid entries of a given type are not reachable from each other, we +//! show 3 lemmas: +//! +//! 1. A bit sequence is not reachable from another if its number of bits equal to +//! 0 is smaller. +//! +//! 2. A bit sequence is not reachable from another if they have the same number of +//! bits equals to 0 and are different. +//! +//! 3. A bit sequence is not reachable from another if it is bigger when they are +//! interpreted as numbers in binary representation. +//! +//! From those lemmas we consider the 2 cases. If both entries have the same number +//! of bits equal to 0, they are either equal or not reachable from each other +//! because of the second lemma. If they don't have the same number of bits equal to +//! 0, then the one with less bits equal to 0 is not reachable from the other +//! because of the first lemma and the one with more bits equal to 0 is not +//! reachable from the other because of the third lemma and the definition of the +//! checksum. +//! +//! # Fuzzing +//! +//! For any sequence of operations and interruptions starting from an erased +//! storage, the store is checked against its model and some internal invariant at +//! each step. +//! +//! For any sequence of operations and interruptions starting from an arbitrary +//! storage, the store is checked not to crash. + #![cfg_attr(not(feature = "std"), no_std)] +#[macro_use] +extern crate alloc; + #[macro_use] mod bitfield; +mod buffer; +mod format; +#[cfg(feature = "std")] +mod model; mod storage; mod store; +pub use self::buffer::{BufferCorruptFunction, BufferOptions, BufferStorage}; +#[cfg(feature = "std")] +pub use self::model::{StoreModel, StoreOperation}; pub use self::storage::{Storage, StorageError, StorageIndex, StorageResult}; -pub use self::store::{StoreError, StoreResult}; +pub use self::store::{StoreError, StoreRatio, StoreResult, StoreUpdate}; diff --git a/libraries/persistent_store/src/model.rs b/libraries/persistent_store/src/model.rs new file mode 100644 index 0000000..2677265 --- /dev/null +++ b/libraries/persistent_store/src/model.rs @@ -0,0 +1,168 @@ +// Copyright 2019-2020 Google LLC +// +// 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. + +use crate::format::Format; +use crate::{StoreError, StoreRatio, StoreResult, StoreUpdate}; +use std::collections::{HashMap, HashSet}; + +/// Models the mutable operations of a store. +/// +/// The model doesn't model the storage and read-only operations. This is done by the driver. +#[derive(Clone, Debug)] +pub struct StoreModel { + /// Represents the content of the store. + content: HashMap>, + + /// The modeled storage configuration. + format: Format, +} + +/// Mutable operations on a store. +#[derive(Clone, Debug)] +pub enum StoreOperation { + /// Applies a transaction. + Transaction { + /// The list of updates to be applied. + updates: Vec, + }, + + /// Deletes all keys above a threshold. + Clear { + /// The minimum key to be deleted. + min_key: usize, + }, + + /// Compacts the store until a given capacity is immediately available. + Prepare { + /// How much capacity should be immediately available after compaction. + length: usize, + }, +} + +impl StoreModel { + /// Creates an empty model for a given storage configuration. + pub fn new(format: Format) -> StoreModel { + let content = HashMap::new(); + StoreModel { content, format } + } + + /// Returns the modeled content. + pub fn content(&self) -> &HashMap> { + &self.content + } + + /// Returns the storage configuration. + pub fn format(&self) -> &Format { + &self.format + } + + /// Simulates a store operation. + pub fn apply(&mut self, operation: StoreOperation) -> StoreResult<()> { + match operation { + StoreOperation::Transaction { updates } => self.transaction(updates), + StoreOperation::Clear { min_key } => self.clear(min_key), + StoreOperation::Prepare { length } => self.prepare(length), + } + } + + /// Returns the capacity according to the model. + pub fn capacity(&self) -> StoreRatio { + let total = self.format.total_capacity(); + let used: usize = self.content.values().map(|x| self.entry_size(x)).sum(); + StoreRatio { used, total } + } + + /// Applies a transaction. + fn transaction(&mut self, updates: Vec) -> StoreResult<()> { + // Fail if too many updates. + if updates.len() > self.format.max_updates() { + return Err(StoreError::InvalidArgument); + } + // Fail if an update is invalid. + if !updates.iter().all(|x| self.update_valid(x)) { + return Err(StoreError::InvalidArgument); + } + // Fail if updates are not disjoint, i.e. there are duplicate keys. + let keys: HashSet<_> = updates.iter().map(|x| x.key()).collect(); + if keys.len() != updates.len() { + return Err(StoreError::InvalidArgument); + } + // Fail if there is not enough capacity. + let capacity = match updates.len() { + // An empty transaction doesn't consume anything. + 0 => 0, + // Transactions with a single update are optimized by avoiding a marker entry. + 1 => match &updates[0] { + StoreUpdate::Insert { value, .. } => self.entry_size(value), + // Transactions with a single update which is a removal don't consume anything. + StoreUpdate::Remove { .. } => 0, + }, + // A transaction consumes one word for the marker entry in addition to its updates. + _ => 1 + updates.iter().map(|x| self.update_size(x)).sum::(), + }; + if self.capacity().remaining() < capacity { + return Err(StoreError::NoCapacity); + } + // Apply the updates. + for update in updates { + match update { + StoreUpdate::Insert { key, value } => { + self.content.insert(key, value.into_boxed_slice()); + } + StoreUpdate::Remove { key } => { + self.content.remove(&key); + } + } + } + Ok(()) + } + + /// Applies a clear operation. + fn clear(&mut self, min_key: usize) -> StoreResult<()> { + if min_key > self.format.max_key() { + return Err(StoreError::InvalidArgument); + } + self.content.retain(|&k, _| k < min_key); + Ok(()) + } + + /// Applies a prepare operation. + fn prepare(&self, length: usize) -> StoreResult<()> { + if self.capacity().remaining() < length { + return Err(StoreError::NoCapacity); + } + Ok(()) + } + + /// Returns the word capacity of an update. + fn update_size(&self, update: &StoreUpdate) -> usize { + match update { + StoreUpdate::Insert { value, .. } => self.entry_size(value), + StoreUpdate::Remove { .. } => 1, + } + } + + /// Returns the word capacity of an entry. + fn entry_size(&self, value: &[u8]) -> usize { + 1 + self.format.bytes_to_words(value.len()) + } + + /// Returns whether an update is valid. + fn update_valid(&self, update: &StoreUpdate) -> bool { + update.key() <= self.format.max_key() + && update + .value() + .map_or(true, |x| x.len() <= self.format.max_value_len()) + } +} diff --git a/libraries/persistent_store/src/store.rs b/libraries/persistent_store/src/store.rs index 0c94196..473310b 100644 --- a/libraries/persistent_store/src/store.rs +++ b/libraries/persistent_store/src/store.rs @@ -13,7 +13,9 @@ // limitations under the License. use crate::StorageError; +use alloc::vec::Vec; +/// Errors returned by store operations. #[derive(Debug, PartialEq, Eq)] pub enum StoreError { /// Invalid argument. @@ -60,4 +62,69 @@ impl From for StoreError { } } +/// Result of store operations. pub type StoreResult = Result; + +/// Progression ratio for store metrics. +/// +/// This is used for the [capacity] and [lifetime] metrics. Those metrics are measured in words. +/// +/// # Invariant +/// +/// - The used value does not exceed the total: `used <= total`. +/// +/// [capacity]: struct.Store.html#method.capacity +/// [lifetime]: struct.Store.html#method.lifetime +#[derive(Copy, Clone, PartialEq, Eq)] +pub struct StoreRatio { + /// How much of the metric is used. + pub(crate) used: usize, + + /// How much of the metric can be used at most. + pub(crate) total: usize, +} + +impl StoreRatio { + /// How much of the metric is used. + pub fn used(self) -> usize { + self.used + } + + /// How much of the metric can be used at most. + pub fn total(self) -> usize { + self.total + } + + /// How much of the metric is remaining. + pub fn remaining(self) -> usize { + self.total - self.used + } +} + +/// Represents an update to the store as part of a transaction. +#[derive(Clone, Debug)] +pub enum StoreUpdate { + /// Inserts or replaces an entry in the store. + Insert { key: usize, value: Vec }, + + /// Removes an entry from the store. + Remove { key: usize }, +} + +impl StoreUpdate { + /// Returns the key affected by the update. + pub fn key(&self) -> usize { + match *self { + StoreUpdate::Insert { key, .. } => key, + StoreUpdate::Remove { key } => key, + } + } + + /// Returns the value written by the update. + pub fn value(&self) -> Option<&[u8]> { + match self { + StoreUpdate::Insert { value, .. } => Some(value), + StoreUpdate::Remove { .. } => None, + } + } +} diff --git a/reproducible/reference_binaries_macos-10.15.sha256sum b/reproducible/reference_binaries_macos-10.15.sha256sum index b7b57c0..b9b1526 100644 --- a/reproducible/reference_binaries_macos-10.15.sha256sum +++ b/reproducible/reference_binaries_macos-10.15.sha256sum @@ -1,9 +1,9 @@ dd5920dfb172d9371b29d019b6a37fae1a995bf9d814000944d9ef36bad31513 third_party/tock/target/thumbv7em-none-eabi/release/nrf52840dk.bin -cf2fb98364ab8520d771090aa59859c1e628c32c01c7b73c000162f579411fc7 target/nrf52840dk_merged.hex +18f111cd3f86b9e06979f2f16465d217bde6af4613e561883c32235992b57099 target/nrf52840dk_merged.hex e4acfa602a5cc5d7c61d465f873918e8e0858628d0e5f8e0db26a7b7dd0b94d4 third_party/tock/target/thumbv7em-none-eabi/release/nrf52840_dongle.bin -588c55ece0bf45d783ca513e12d4072668d9749b9320a13380fcc498a2855a7b target/nrf52840_dongle_merged.hex +dd283a1949a9ffb7bf81ef5a0dcd4c45adfb8dda8344a672bff160a917e0b6b9 target/nrf52840_dongle_merged.hex c0ace9f13ef3fd18c576a735ae23b3956bf8dd346f20c6217086e748d6bad8a2 third_party/tock/target/thumbv7em-none-eabi/release/nrf52840_dongle_dfu.bin -4b3f87e9bb992198f5885cc689e1cf1f8e93519f107614d316473ef43f8be7a4 target/nrf52840_dongle_dfu_merged.hex +11c0dad7abd513066732952fd5ad9988b0b45339683d93fcd8f4660d62d93aa1 target/nrf52840_dongle_dfu_merged.hex 06a38a0d6d356145467a73c765e28a945878f663664016f888393207097bfe10 third_party/tock/target/thumbv7em-none-eabi/release/nrf52840_mdk_dfu.bin -c35a1501eed3024821f0f17f2a50e1c27925ccabee4c633e10fa10e5bcd197ac target/nrf52840_mdk_dfu_merged.hex -17cd41e1ab1bfa683b5ec79333779a95965668fea146d2a178ca35ab20b16ece target/tab/ctap2.tab +c584d6e22b0a4a80fccc1e557ed95c744a02f12107f7a5b3c5ec31f06a0f781f target/nrf52840_mdk_dfu_merged.hex +c56962d46ad423b61bb0edc39d8a4a135c22e59fee440ddbfcade3f8136e7b39 target/tab/ctap2.tab diff --git a/reproducible/reference_binaries_ubuntu-18.04.sha256sum b/reproducible/reference_binaries_ubuntu-18.04.sha256sum index e20ee78..9555836 100644 --- a/reproducible/reference_binaries_ubuntu-18.04.sha256sum +++ b/reproducible/reference_binaries_ubuntu-18.04.sha256sum @@ -1,9 +1,9 @@ 2426ee9a6c75e325537818081d45445d95468a4c0a77feacdc6133d7d9aa227a third_party/tock/target/thumbv7em-none-eabi/release/nrf52840dk.bin -c0cdbad7d4d7d9bd64ad7db43046ada19990b8f43a88e6ec3f508bb233827966 target/nrf52840dk_merged.hex +a5c6deb3931715c003ad79ccd2847bf5085b20d888908f5b589531077f55752f target/nrf52840dk_merged.hex c53d1e1db72df25950fa6d28699a2d38757def0dcbeb0d09d2366481cf0149a6 third_party/tock/target/thumbv7em-none-eabi/release/nrf52840_dongle.bin -7bb26ae63b60e136852133c0da1d1cbf550a98012f9ba3bb4d27fc682a504880 target/nrf52840_dongle_merged.hex +eff4f034398895536391d52e3874c15b7952dd113e455994b09847ed9fb04160 target/nrf52840_dongle_merged.hex 233b5ba4459523759e3171cee83cdb3a383bbe65727c8ece64dfe5321d6ebe34 third_party/tock/target/thumbv7em-none-eabi/release/nrf52840_dongle_dfu.bin -fbcc441dc5faf87baffe57226fd52c8e63804cd0d76f04057474954a74985217 target/nrf52840_dongle_dfu_merged.hex +29c664a35a3e400a1608573e56313bf1364e648174467e4a64de78c434a5caf0 target/nrf52840_dongle_dfu_merged.hex 1baaf518a74c6077cb936d9cf178b6dd0232e7562fa56174886b05b77886cc32 third_party/tock/target/thumbv7em-none-eabi/release/nrf52840_mdk_dfu.bin -80c430b911c967dcf1d60d7456d381162a342733e4e42a6f64f855120339de35 target/nrf52840_mdk_dfu_merged.hex -62b4bea855a5757fe70c2690f8c05d8ed0078d688de07b6695f9f73bc265f2f6 target/tab/ctap2.tab +0d175e760518c1734b425e291f0d60c39b4f5e8c96dbffca5f17f4fc225551f0 target/nrf52840_mdk_dfu_merged.hex +cfad3b9f3d6ee1a80f4e47a66af49875c19c37c363699780529f946c6c9c29b9 target/tab/ctap2.tab diff --git a/reproducible/reference_elf2tab_macos-10.15.txt b/reproducible/reference_elf2tab_macos-10.15.txt index 7360266..27e0332 100644 --- a/reproducible/reference_elf2tab_macos-10.15.txt +++ b/reproducible/reference_elf2tab_macos-10.15.txt @@ -6,8 +6,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187320 (0x2dbb8) bytes. - Adding .stack section. Offset: 187448 (0x2dc38). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 187288 (0x2db98) bytes. + Adding .stack section. Offset: 187416 (0x2dc18). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 @@ -30,8 +30,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187320 (0x2dbb8) bytes. - Adding .stack section. Offset: 187448 (0x2dc38). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 187288 (0x2db98) bytes. + Adding .stack section. Offset: 187416 (0x2dc18). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 @@ -54,8 +54,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187320 (0x2dbb8) bytes. - Adding .stack section. Offset: 187448 (0x2dc38). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 187288 (0x2db98) bytes. + Adding .stack section. Offset: 187416 (0x2dc18). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 @@ -78,8 +78,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187320 (0x2dbb8) bytes. - Adding .stack section. Offset: 187448 (0x2dc38). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 187288 (0x2db98) bytes. + Adding .stack section. Offset: 187416 (0x2dc18). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 diff --git a/reproducible/reference_elf2tab_ubuntu-18.04.txt b/reproducible/reference_elf2tab_ubuntu-18.04.txt index 7e58539..e485a5c 100644 --- a/reproducible/reference_elf2tab_ubuntu-18.04.txt +++ b/reproducible/reference_elf2tab_ubuntu-18.04.txt @@ -6,8 +6,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187008 (0x2da80) bytes. - Adding .stack section. Offset: 187136 (0x2db00). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 186992 (0x2da70) bytes. + Adding .stack section. Offset: 187120 (0x2daf0). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 @@ -30,8 +30,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187008 (0x2da80) bytes. - Adding .stack section. Offset: 187136 (0x2db00). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 186992 (0x2da70) bytes. + Adding .stack section. Offset: 187120 (0x2daf0). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 @@ -54,8 +54,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187008 (0x2da80) bytes. - Adding .stack section. Offset: 187136 (0x2db00). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 186992 (0x2da70) bytes. + Adding .stack section. Offset: 187120 (0x2daf0). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 @@ -78,8 +78,8 @@ Min RAM size from segments in ELF: 20 bytes Number of writeable flash regions: 0 Adding .crt0_header section. Offset: 64 (0x40). Length: 64 (0x40) bytes. Entry point is in .text section - Adding .text section. Offset: 128 (0x80). Length: 187008 (0x2da80) bytes. - Adding .stack section. Offset: 187136 (0x2db00). Length: 16384 (0x4000) bytes. + Adding .text section. Offset: 128 (0x80). Length: 186992 (0x2da70) bytes. + Adding .stack section. Offset: 187120 (0x2daf0). Length: 16384 (0x4000) bytes. Searching for .rel.X sections to add. TBF Header: version: 2 0x2 diff --git a/src/ctap/mod.rs b/src/ctap/mod.rs index 8d881b3..442d942 100644 --- a/src/ctap/mod.rs +++ b/src/ctap/mod.rs @@ -373,7 +373,7 @@ where } (extensions.hmac_secret, cred_protect) } else { - (false, None) + (false, DEFAULT_CRED_PROTECT) }; let cred_random = if use_hmac_extension { diff --git a/third_party/libtock-drivers/Cargo.toml b/third_party/libtock-drivers/Cargo.toml index 74fe7ac..41e5c32 100644 --- a/third_party/libtock-drivers/Cargo.toml +++ b/third_party/libtock-drivers/Cargo.toml @@ -14,3 +14,4 @@ libtock_core = { path = "../../third_party/libtock-rs/core" } [features] debug_ctap = [] verbose_usb = ["debug_ctap"] +with_nfc=[] diff --git a/third_party/libtock-drivers/src/lib.rs b/third_party/libtock-drivers/src/lib.rs index bf62d05..8b8983c 100644 --- a/third_party/libtock-drivers/src/lib.rs +++ b/third_party/libtock-drivers/src/lib.rs @@ -3,6 +3,8 @@ pub mod buttons; pub mod console; pub mod led; +#[cfg(feature = "with_nfc")] +pub mod nfc; pub mod result; pub mod rng; pub mod timer;