xref: /openbmc/u-boot/lib/lz4_wrapper.c (revision baefb63a)
1 /*
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 
12 static u16 LZ4_readLE16(const void *src) { return le16_to_cpu(*(u16 *)src); }
13 static void LZ4_copy4(void *dst, const void *src) { *(u32 *)dst = *(u32 *)src; }
14 static void LZ4_copy8(void *dst, const void *src) { *(u64 *)dst = *(u64 *)src; }
15 
16 typedef  uint8_t BYTE;
17 typedef uint16_t U16;
18 typedef uint32_t U32;
19 typedef  int32_t S32;
20 typedef 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 
29 struct 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 
54 struct 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 
66 int 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) {
97 		struct lz4_block_header b;
98 
99 		b.raw = le32_to_cpu(*(u32 *)in);
100 		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 }
140