1 // SPDX-License-Identifier: GPL 2.0+ OR BSD-3-Clause 2 /* 3 * Copyright 2015 Google Inc. 4 */ 5 6 #include <common.h> 7 #include <compiler.h> 8 #include <linux/kernel.h> 9 #include <linux/types.h> 10 11 static u16 LZ4_readLE16(const void *src) { return le16_to_cpu(*(u16 *)src); } 12 static void LZ4_copy4(void *dst, const void *src) { *(u32 *)dst = *(u32 *)src; } 13 static void LZ4_copy8(void *dst, const void *src) { *(u64 *)dst = *(u64 *)src; } 14 15 typedef uint8_t BYTE; 16 typedef uint16_t U16; 17 typedef uint32_t U32; 18 typedef int32_t S32; 19 typedef uint64_t U64; 20 21 #define FORCE_INLINE static inline __attribute__((always_inline)) 22 23 /* Unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */ 24 #include "lz4.c" /* #include for inlining, do not link! */ 25 26 #define LZ4F_MAGIC 0x184D2204 27 28 struct lz4_frame_header { 29 u32 magic; 30 union { 31 u8 flags; 32 struct { 33 u8 reserved0:2; 34 u8 has_content_checksum:1; 35 u8 has_content_size:1; 36 u8 has_block_checksum:1; 37 u8 independent_blocks:1; 38 u8 version:2; 39 }; 40 }; 41 union { 42 u8 block_descriptor; 43 struct { 44 u8 reserved1:4; 45 u8 max_block_size:3; 46 u8 reserved2:1; 47 }; 48 }; 49 /* + u64 content_size iff has_content_size is set */ 50 /* + u8 header_checksum */ 51 } __packed; 52 53 struct lz4_block_header { 54 union { 55 u32 raw; 56 struct { 57 u32 size:31; 58 u32 not_compressed:1; 59 }; 60 }; 61 /* + size bytes of data */ 62 /* + u32 block_checksum iff has_block_checksum is set */ 63 } __packed; 64 65 int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn) 66 { 67 const void *end = dst + *dstn; 68 const void *in = src; 69 void *out = dst; 70 int has_block_checksum; 71 int ret; 72 *dstn = 0; 73 74 { /* With in-place decompression the header may become invalid later. */ 75 const struct lz4_frame_header *h = in; 76 77 if (srcn < sizeof(*h) + sizeof(u64) + sizeof(u8)) 78 return -EINVAL; /* input overrun */ 79 80 /* We assume there's always only a single, standard frame. */ 81 if (le32_to_cpu(h->magic) != LZ4F_MAGIC || h->version != 1) 82 return -EPROTONOSUPPORT; /* unknown format */ 83 if (h->reserved0 || h->reserved1 || h->reserved2) 84 return -EINVAL; /* reserved must be zero */ 85 if (!h->independent_blocks) 86 return -EPROTONOSUPPORT; /* we can't support this yet */ 87 has_block_checksum = h->has_block_checksum; 88 89 in += sizeof(*h); 90 if (h->has_content_size) 91 in += sizeof(u64); 92 in += sizeof(u8); 93 } 94 95 while (1) { 96 struct lz4_block_header b; 97 98 b.raw = le32_to_cpu(*(u32 *)in); 99 in += sizeof(struct lz4_block_header); 100 101 if (in - src + b.size > srcn) { 102 ret = -EINVAL; /* input overrun */ 103 break; 104 } 105 106 if (!b.size) { 107 ret = 0; /* decompression successful */ 108 break; 109 } 110 111 if (b.not_compressed) { 112 size_t size = min((ptrdiff_t)b.size, end - out); 113 memcpy(out, in, size); 114 out += size; 115 if (size < b.size) { 116 ret = -ENOBUFS; /* output overrun */ 117 break; 118 } 119 } else { 120 /* constant folding essential, do not touch params! */ 121 ret = LZ4_decompress_generic(in, out, b.size, 122 end - out, endOnInputSize, 123 full, 0, noDict, out, NULL, 0); 124 if (ret < 0) { 125 ret = -EPROTO; /* decompression error */ 126 break; 127 } 128 out += ret; 129 } 130 131 in += b.size; 132 if (has_block_checksum) 133 in += sizeof(u32); 134 } 135 136 *dstn = out - dst; 137 return ret; 138 } 139