blob: 6dc8b764b3f59ecb4bd9fedf46d72832a57e2488 [file] [log] [blame]
Julius Werner027b7282015-10-06 20:03:53 -07001/*
2 * Copyright 2015 Google Inc.
3 *
4 * SPDX-License-Identifier: GPL 2.0+ BSD-3-Clause
5 */
6
7#include <common.h>
8#include <compiler.h>
9#include <linux/kernel.h>
10#include <linux/types.h>
11
12static u16 LZ4_readLE16(const void *src) { return le16_to_cpu(*(u16 *)src); }
13static void LZ4_copy4(void *dst, const void *src) { *(u32 *)dst = *(u32 *)src; }
14static void LZ4_copy8(void *dst, const void *src) { *(u64 *)dst = *(u64 *)src; }
15
16typedef uint8_t BYTE;
17typedef uint16_t U16;
18typedef uint32_t U32;
19typedef int32_t S32;
20typedef uint64_t U64;
21
22#define FORCE_INLINE static inline __attribute__((always_inline))
23
24/* Unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */
25#include "lz4.c" /* #include for inlining, do not link! */
26
27#define LZ4F_MAGIC 0x184D2204
28
29struct lz4_frame_header {
30 u32 magic;
31 union {
32 u8 flags;
33 struct {
34 u8 reserved0:2;
35 u8 has_content_checksum:1;
36 u8 has_content_size:1;
37 u8 has_block_checksum:1;
38 u8 independent_blocks:1;
39 u8 version:2;
40 };
41 };
42 union {
43 u8 block_descriptor;
44 struct {
45 u8 reserved1:4;
46 u8 max_block_size:3;
47 u8 reserved2:1;
48 };
49 };
50 /* + u64 content_size iff has_content_size is set */
51 /* + u8 header_checksum */
52} __packed;
53
54struct lz4_block_header {
55 union {
56 u32 raw;
57 struct {
58 u32 size:31;
59 u32 not_compressed:1;
60 };
61 };
62 /* + size bytes of data */
63 /* + u32 block_checksum iff has_block_checksum is set */
64} __packed;
65
66int ulz4fn(const void *src, size_t srcn, void *dst, size_t *dstn)
67{
68 const void *end = dst + *dstn;
69 const void *in = src;
70 void *out = dst;
71 int has_block_checksum;
72 int ret;
73 *dstn = 0;
74
75 { /* With in-place decompression the header may become invalid later. */
76 const struct lz4_frame_header *h = in;
77
78 if (srcn < sizeof(*h) + sizeof(u64) + sizeof(u8))
79 return -EINVAL; /* input overrun */
80
81 /* We assume there's always only a single, standard frame. */
82 if (le32_to_cpu(h->magic) != LZ4F_MAGIC || h->version != 1)
83 return -EPROTONOSUPPORT; /* unknown format */
84 if (h->reserved0 || h->reserved1 || h->reserved2)
85 return -EINVAL; /* reserved must be zero */
86 if (!h->independent_blocks)
87 return -EPROTONOSUPPORT; /* we can't support this yet */
88 has_block_checksum = h->has_block_checksum;
89
90 in += sizeof(*h);
91 if (h->has_content_size)
92 in += sizeof(u64);
93 in += sizeof(u8);
94 }
95
96 while (1) {
Stephen Warren60f989a2015-11-14 23:53:49 -070097 struct lz4_block_header b;
98
99 b.raw = le32_to_cpu(*(u32 *)in);
Julius Werner027b7282015-10-06 20:03:53 -0700100 in += sizeof(struct lz4_block_header);
101
102 if (in - src + b.size > srcn) {
103 ret = -EINVAL; /* input overrun */
104 break;
105 }
106
107 if (!b.size) {
108 ret = 0; /* decompression successful */
109 break;
110 }
111
112 if (b.not_compressed) {
113 size_t size = min((ptrdiff_t)b.size, end - out);
114 memcpy(out, in, size);
115 out += size;
116 if (size < b.size) {
117 ret = -ENOBUFS; /* output overrun */
118 break;
119 }
120 } else {
121 /* constant folding essential, do not touch params! */
122 ret = LZ4_decompress_generic(in, out, b.size,
123 end - out, endOnInputSize,
124 full, 0, noDict, out, NULL, 0);
125 if (ret < 0) {
126 ret = -EPROTO; /* decompression error */
127 break;
128 }
129 out += ret;
130 }
131
132 in += b.size;
133 if (has_block_checksum)
134 in += sizeof(u32);
135 }
136
137 *dstn = out - dst;
138 return ret;
139}