1 // SPDX-License-Identifier: GPL-2.0 2 #include <errno.h> 3 #include <lzma.h> 4 #include <stdio.h> 5 #include <linux/compiler.h> 6 #include <sys/types.h> 7 #include <sys/stat.h> 8 #include <fcntl.h> 9 #include "compress.h" 10 #include "util.h" 11 #include "debug.h" 12 #include <unistd.h> 13 14 #define BUFSIZE 8192 15 16 static const char *lzma_strerror(lzma_ret ret) 17 { 18 switch ((int) ret) { 19 case LZMA_MEM_ERROR: 20 return "Memory allocation failed"; 21 case LZMA_OPTIONS_ERROR: 22 return "Unsupported decompressor flags"; 23 case LZMA_FORMAT_ERROR: 24 return "The input is not in the .xz format"; 25 case LZMA_DATA_ERROR: 26 return "Compressed file is corrupt"; 27 case LZMA_BUF_ERROR: 28 return "Compressed file is truncated or otherwise corrupt"; 29 default: 30 return "Unknown error, possibly a bug"; 31 } 32 } 33 34 int lzma_decompress_to_file(const char *input, int output_fd) 35 { 36 lzma_action action = LZMA_RUN; 37 lzma_stream strm = LZMA_STREAM_INIT; 38 lzma_ret ret; 39 int err = -1; 40 41 u8 buf_in[BUFSIZE]; 42 u8 buf_out[BUFSIZE]; 43 FILE *infile; 44 45 infile = fopen(input, "rb"); 46 if (!infile) { 47 pr_err("lzma: fopen failed on %s: '%s'\n", 48 input, strerror(errno)); 49 return -1; 50 } 51 52 ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED); 53 if (ret != LZMA_OK) { 54 pr_err("lzma: lzma_stream_decoder failed %s (%d)\n", 55 lzma_strerror(ret), ret); 56 goto err_fclose; 57 } 58 59 strm.next_in = NULL; 60 strm.avail_in = 0; 61 strm.next_out = buf_out; 62 strm.avail_out = sizeof(buf_out); 63 64 while (1) { 65 if (strm.avail_in == 0 && !feof(infile)) { 66 strm.next_in = buf_in; 67 strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile); 68 69 if (ferror(infile)) { 70 pr_err("lzma: read error: %s\n", strerror(errno)); 71 goto err_fclose; 72 } 73 74 if (feof(infile)) 75 action = LZMA_FINISH; 76 } 77 78 ret = lzma_code(&strm, action); 79 80 if (strm.avail_out == 0 || ret == LZMA_STREAM_END) { 81 ssize_t write_size = sizeof(buf_out) - strm.avail_out; 82 83 if (writen(output_fd, buf_out, write_size) != write_size) { 84 pr_err("lzma: write error: %s\n", strerror(errno)); 85 goto err_fclose; 86 } 87 88 strm.next_out = buf_out; 89 strm.avail_out = sizeof(buf_out); 90 } 91 92 if (ret != LZMA_OK) { 93 if (ret == LZMA_STREAM_END) 94 break; 95 96 pr_err("lzma: failed %s\n", lzma_strerror(ret)); 97 goto err_fclose; 98 } 99 } 100 101 err = 0; 102 err_fclose: 103 fclose(infile); 104 return err; 105 } 106 107 bool lzma_is_compressed(const char *input) 108 { 109 int fd = open(input, O_RDONLY); 110 const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 }; 111 char buf[6] = { 0 }; 112 ssize_t rc; 113 114 if (fd < 0) 115 return -1; 116 117 rc = read(fd, buf, sizeof(buf)); 118 close(fd); 119 return rc == sizeof(buf) ? 120 memcmp(buf, magic, sizeof(buf)) == 0 : false; 121 } 122