/* * Copyright 2015 Google Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <assert.h> #include <endian.h> #include <libpayload.h> #include <lz4.h> /* LZ4 comes with its own supposedly portable memory access functions, but they * seem to be very inefficient in practice (at least on ARM64). Since libpayload * knows about endinaness and allows some basic assumptions (such as unaligned * access support), we can easily write the ones we need ourselves. */ static u16 LZ4_readLE16(const void *src) { return le16toh(*(u16 *)src); } static void LZ4_copy4(void *dst, const void *src) { *(u32 *)dst = *(u32 *)src; } static void LZ4_copy8(void *dst, const void *src) { *(u64 *)dst = *(u64 *)src; } typedef uint8_t BYTE; typedef uint16_t U16; typedef uint32_t U32; typedef int32_t S32; typedef uint64_t U64; #define FORCE_INLINE static inline __attribute__((always_inline)) #define likely(expr) __builtin_expect((expr) != 0, 1) #define unlikely(expr) __builtin_expect((expr) != 0, 0) /* Unaltered (except removing unrelated code) from github.com/Cyan4973/lz4. */ #include "lz4.c" /* #include for inlining, do not link! */ #define LZ4F_MAGICNUMBER 0x184D2204 struct lz4_frame_header { u32 magic; union { u8 flags; struct { u8 reserved0 : 2; u8 has_content_checksum : 1; u8 has_content_size : 1; u8 has_block_checksum : 1; u8 independent_blocks : 1; u8 version : 2; }; }; union { u8 block_descriptor; struct { u8 reserved1 : 4; u8 max_block_size : 3; u8 reserved2 : 1; }; }; /* + u64 content_size iff has_content_size is set */ /* + u8 header_checksum */ } __attribute__((packed)); struct lz4_block_header { union { u32 raw; struct { u32 size : 31; u32 not_compressed : 1; }; }; /* + size bytes of data */ /* + u32 block_checksum iff has_block_checksum is set */ } __attribute__((packed)); size_t ulz4fn(const void *src, size_t srcn, void *dst, size_t dstn) { const void *in = src; void *out = dst; int has_block_checksum; { /* With in-place decompression the header may become invalid later. */ const struct lz4_frame_header *h = in; if (srcn < sizeof(*h) + sizeof(u64) + sizeof(u8)) return 0; /* input overrun */ /* We assume there's always only a single, standard frame. */ if (le32toh(h->magic) != LZ4F_MAGICNUMBER || h->version != 1) return 0; /* unknown format */ if (h->reserved0 || h->reserved1 || h->reserved2) return 0; /* reserved must be zero */ if (!h->independent_blocks) return 0; /* we don't support block dependency */ has_block_checksum = h->has_block_checksum; in += sizeof(*h); if (h->has_content_size) in += sizeof(u64); in += sizeof(u8); } while (1) { struct lz4_block_header b = { .raw = le32toh(*(u32 *)in) }; in += sizeof(struct lz4_block_header); if (in - src + b.size > srcn) return 0; /* input overrun */ if (!b.size) return out - dst; /* decompression successful */ if (b.not_compressed) { size_t size = MIN((u32)b.size, dst + dstn - out); memcpy(out, in, size); if (size < b.size) return 0; /* output overrun */ else out += size; } else { /* constant folding essential, do not touch params! */ int ret = LZ4_decompress_generic(in, out, b.size, dst + dstn - out, endOnInputSize, full, 0, noDict, out, NULL, 0); if (ret < 0) return 0; /* decompression error */ else out += ret; } in += b.size; if (has_block_checksum) in += sizeof(u32); } } size_t ulz4f(const void *src, void *dst) { /* LZ4 uses signed size parameters, so can't just use ((u32)-1) here. */ return ulz4fn(src, 1*GiB, dst, 1*GiB); }