1 files changed, 111 insertions, 0 deletions
diff --git a/fluent-bit/lib/cfl/src/cfl_checksum.c b/fluent-bit/lib/cfl/src/cfl_checksum.c
new file mode 100644
index 00000000..9b0297ea
--- /dev/null
+++ b/fluent-bit/lib/cfl/src/cfl_checksum.c
@@ -0,0 +1,111 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  CFL
+ *  ===
+ *  Copyright (C) 2022 The CFL Authors
+ *
+ *  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.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+
+static const uint32_t crc32c_table[256] = {
+    0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
+    0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
+    0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
+    0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
+    0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
+    0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
+    0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
+    0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
+    0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
+    0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
+    0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
+    0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
+    0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
+    0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
+    0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
+    0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
+    0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
+    0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
+    0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
+    0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
+    0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
+    0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
+    0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
+    0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
+    0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
+    0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
+    0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
+    0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
+    0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
+    0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
+    0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
+    0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
+    0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
+    0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
+    0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
+    0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
+    0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
+    0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
+    0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
+    0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
+    0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
+    0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
+    0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
+    0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
+    0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
+    0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
+    0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
+    0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
+    0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
+    0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
+    0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
+    0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
+    0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
+    0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
+    0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
+    0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
+    0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
+    0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
+    0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
+    0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
+    0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
+    0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
+    0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
+    0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351
+};
+
+uint32_t cfl_checksum_crc32c(unsigned char *buffer, size_t length)
+{
+    uint32_t checksum_table_index;
+    uint32_t checksum;
+    size_t   index;
+
+    checksum = 0xFFFFFFFF;
+
+    /* Keeping in mind that compilers are smart enough to optimize these
+     * expensive divisions / modulo with bitwise operations it makes no sense
+     * to make this code cryptic.
+     */
+
+    for (index = 0 ; index < length ; index++) {
+        checksum_table_index  = checksum ^ buffer[index];
+        checksum_table_index %= 256;
+
+        checksum = crc32c_table[checksum_table_index] ^ (checksum / 256);
+    }
+
+    return checksum ^ 0xFFFFFFFF;
+}