| Marek Behún | 21a14fa | 2017-09-03 17:00:28 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * BTRFS filesystem implementation for U-Boot |
| 3 | * |
| 4 | * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz |
| 5 | * |
| 6 | * SPDX-License-Identifier: GPL-2.0+ |
| 7 | */ |
| 8 | |
| 9 | #include "btrfs.h" |
| 10 | #include <linux/lzo.h> |
| 11 | #include <u-boot/zlib.h> |
| 12 | |
| 13 | static u32 decompress_lzo(const u8 *cbuf, u32 clen, u8 *dbuf, u32 dlen) |
| 14 | { |
| 15 | u32 tot_len, in_len, res; |
| 16 | size_t out_len; |
| 17 | int ret; |
| 18 | |
| 19 | if (clen < 4) |
| 20 | return -1; |
| 21 | |
| 22 | tot_len = le32_to_cpu(*(u32 *) cbuf); |
| 23 | cbuf += 4; |
| 24 | clen -= 4; |
| 25 | tot_len -= 4; |
| 26 | |
| 27 | if (tot_len == 0 && dlen) |
| 28 | return -1; |
| 29 | if (tot_len < 4) |
| 30 | return -1; |
| 31 | |
| 32 | res = 0; |
| 33 | |
| 34 | while (tot_len > 4) { |
| 35 | in_len = le32_to_cpu(*(u32 *) cbuf); |
| 36 | cbuf += 4; |
| 37 | clen -= 4; |
| 38 | |
| 39 | if (in_len > clen || tot_len < 4 + in_len) |
| 40 | return -1; |
| 41 | |
| 42 | tot_len -= 4 + in_len; |
| 43 | |
| 44 | out_len = dlen; |
| 45 | ret = lzo1x_decompress_safe(cbuf, in_len, dbuf, &out_len); |
| 46 | if (ret != LZO_E_OK) |
| 47 | return -1; |
| 48 | |
| 49 | cbuf += in_len; |
| 50 | clen -= in_len; |
| 51 | dbuf += out_len; |
| 52 | dlen -= out_len; |
| 53 | |
| 54 | res += out_len; |
| 55 | } |
| 56 | |
| 57 | return res; |
| 58 | } |
| 59 | |
| 60 | /* from zutil.h */ |
| 61 | #define PRESET_DICT 0x20 |
| 62 | |
| 63 | static u32 decompress_zlib(const u8 *_cbuf, u32 clen, u8 *dbuf, u32 dlen) |
| 64 | { |
| 65 | int wbits = MAX_WBITS, ret = -1; |
| 66 | z_stream stream; |
| 67 | u8 *cbuf; |
| 68 | u32 res; |
| 69 | |
| 70 | memset(&stream, 0, sizeof(stream)); |
| 71 | |
| 72 | cbuf = (u8 *) _cbuf; |
| 73 | |
| 74 | stream.total_in = 0; |
| 75 | |
| 76 | stream.next_out = dbuf; |
| 77 | stream.avail_out = dlen; |
| 78 | stream.total_out = 0; |
| 79 | |
| 80 | /* skip adler32 check if deflate and no dictionary */ |
| 81 | if (clen > 2 && !(cbuf[1] & PRESET_DICT) && |
| 82 | ((cbuf[0] & 0x0f) == Z_DEFLATED) && |
| 83 | !(((cbuf[0] << 8) + cbuf[1]) % 31)) { |
| 84 | wbits = -((cbuf[0] >> 4) + 8); |
| 85 | cbuf += 2; |
| 86 | clen -= 2; |
| 87 | } |
| 88 | |
| 89 | if (Z_OK != inflateInit2(&stream, wbits)) |
| 90 | return -1; |
| 91 | |
| 92 | while (stream.total_in < clen) { |
| 93 | stream.next_in = cbuf + stream.total_in; |
| 94 | stream.avail_in = min((u32) (clen - stream.total_in), |
| 95 | (u32) btrfs_info.sb.sectorsize); |
| 96 | |
| 97 | ret = inflate(&stream, Z_NO_FLUSH); |
| 98 | if (ret != Z_OK) |
| 99 | break; |
| 100 | } |
| 101 | |
| 102 | res = stream.total_out; |
| 103 | inflateEnd(&stream); |
| 104 | |
| 105 | if (ret != Z_STREAM_END) |
| 106 | return -1; |
| 107 | |
| 108 | return res; |
| 109 | } |
| 110 | |
| 111 | u32 btrfs_decompress(u8 type, const char *c, u32 clen, char *d, u32 dlen) |
| 112 | { |
| 113 | u32 res; |
| 114 | const u8 *cbuf; |
| 115 | u8 *dbuf; |
| 116 | |
| 117 | cbuf = (const u8 *) c; |
| 118 | dbuf = (u8 *) d; |
| 119 | |
| 120 | switch (type) { |
| 121 | case BTRFS_COMPRESS_NONE: |
| 122 | res = dlen < clen ? dlen : clen; |
| 123 | memcpy(dbuf, cbuf, res); |
| 124 | return res; |
| 125 | case BTRFS_COMPRESS_ZLIB: |
| 126 | return decompress_zlib(cbuf, clen, dbuf, dlen); |
| 127 | case BTRFS_COMPRESS_LZO: |
| 128 | return decompress_lzo(cbuf, clen, dbuf, dlen); |
| 129 | default: |
| 130 | printf("%s: Unsupported compression in extent: %i\n", __func__, |
| 131 | type); |
| 132 | return -1; |
| 133 | } |
| 134 | } |