| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | #include <stdio.h> |
| 3 | #include <unistd.h> |
| 4 | #include <sys/stat.h> |
| 5 | #include <sys/mman.h> |
| 6 | #include <zlib.h> |
| 7 | |
| 8 | #include "util/compress.h" |
| 9 | #include "util/util.h" |
| 10 | #include "util/debug.h" |
| 11 | |
| 12 | |
| 13 | #define CHUNK_SIZE 16384 |
| 14 | |
| 15 | int gzip_decompress_to_file(const char *input, int output_fd) |
| 16 | { |
| 17 | int ret = Z_STREAM_ERROR; |
| 18 | int input_fd; |
| 19 | void *ptr; |
| 20 | int len; |
| 21 | struct stat stbuf; |
| 22 | unsigned char buf[CHUNK_SIZE]; |
| 23 | z_stream zs = { |
| 24 | .zalloc = Z_NULL, |
| 25 | .zfree = Z_NULL, |
| 26 | .opaque = Z_NULL, |
| 27 | .avail_in = 0, |
| 28 | .next_in = Z_NULL, |
| 29 | }; |
| 30 | |
| 31 | input_fd = open(input, O_RDONLY); |
| 32 | if (input_fd < 0) |
| 33 | return -1; |
| 34 | |
| 35 | if (fstat(input_fd, &stbuf) < 0) |
| 36 | goto out_close; |
| 37 | |
| 38 | ptr = mmap(NULL, stbuf.st_size, PROT_READ, MAP_PRIVATE, input_fd, 0); |
| 39 | if (ptr == MAP_FAILED) |
| 40 | goto out_close; |
| 41 | |
| 42 | if (inflateInit2(&zs, 16 + MAX_WBITS) != Z_OK) |
| 43 | goto out_unmap; |
| 44 | |
| 45 | zs.next_in = ptr; |
| 46 | zs.avail_in = stbuf.st_size; |
| 47 | |
| 48 | do { |
| 49 | zs.next_out = buf; |
| 50 | zs.avail_out = CHUNK_SIZE; |
| 51 | |
| 52 | ret = inflate(&zs, Z_NO_FLUSH); |
| 53 | switch (ret) { |
| 54 | case Z_NEED_DICT: |
| 55 | ret = Z_DATA_ERROR; |
| 56 | /* fall through */ |
| 57 | case Z_DATA_ERROR: |
| 58 | case Z_MEM_ERROR: |
| 59 | goto out; |
| 60 | default: |
| 61 | break; |
| 62 | } |
| 63 | |
| 64 | len = CHUNK_SIZE - zs.avail_out; |
| 65 | if (writen(output_fd, buf, len) != len) { |
| 66 | ret = Z_DATA_ERROR; |
| 67 | goto out; |
| 68 | } |
| 69 | |
| 70 | } while (ret != Z_STREAM_END); |
| 71 | |
| 72 | out: |
| 73 | inflateEnd(&zs); |
| 74 | out_unmap: |
| 75 | munmap(ptr, stbuf.st_size); |
| 76 | out_close: |
| 77 | close(input_fd); |
| 78 | |
| 79 | return ret == Z_STREAM_END ? 0 : -1; |
| 80 | } |