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 "debug.h" 11 #include <string.h> 12 #include <unistd.h> 13 #include <internal/lib.h> 14 15 #define BUFSIZE 8192 16 17 static const char *lzma_strerror(lzma_ret ret) 18 { 19 switch ((int) ret) { 20 case LZMA_MEM_ERROR: 21 return "Memory allocation failed"; 22 case LZMA_OPTIONS_ERROR: 23 return "Unsupported decompressor flags"; 24 case LZMA_FORMAT_ERROR: 25 return "The input is not in the .xz format"; 26 case LZMA_DATA_ERROR: 27 return "Compressed file is corrupt"; 28 case LZMA_BUF_ERROR: 29 return "Compressed file is truncated or otherwise corrupt"; 30 default: 31 return "Unknown error, possibly a bug"; 32 } 33 } 34 35 int lzma_decompress_to_file(const char *input, int output_fd) 36 { 37 lzma_action action = LZMA_RUN; 38 lzma_stream strm = LZMA_STREAM_INIT; 39 lzma_ret ret; 40 int err = -1; 41 42 u8 buf_in[BUFSIZE]; 43 u8 buf_out[BUFSIZE]; 44 FILE *infile; 45 46 infile = fopen(input, "rb"); 47 if (!infile) { 48 pr_err("lzma: fopen failed on %s: '%s'\n", 49 input, strerror(errno)); 50 return -1; 51 } 52 53 ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED); 54 if (ret != LZMA_OK) { 55 pr_err("lzma: lzma_stream_decoder failed %s (%d)\n", 56 lzma_strerror(ret), ret); 57 goto err_fclose; 58 } 59 60 strm.next_in = NULL; 61 strm.avail_in = 0; 62 strm.next_out = buf_out; 63 strm.avail_out = sizeof(buf_out); 64 65 while (1) { 66 if (strm.avail_in == 0 && !feof(infile)) { 67 strm.next_in = buf_in; 68 strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile); 69 70 if (ferror(infile)) { 71 pr_err("lzma: read error: %s\n", strerror(errno)); 72 goto err_lzma_end; 73 } 74 75 if (feof(infile)) 76 action = LZMA_FINISH; 77 } 78 79 ret = lzma_code(&strm, action); 80 81 if (strm.avail_out == 0 || ret == LZMA_STREAM_END) { 82 ssize_t write_size = sizeof(buf_out) - strm.avail_out; 83 84 if (writen(output_fd, buf_out, write_size) != write_size) { 85 pr_err("lzma: write error: %s\n", strerror(errno)); 86 goto err_lzma_end; 87 } 88 89 strm.next_out = buf_out; 90 strm.avail_out = sizeof(buf_out); 91 } 92 93 if (ret != LZMA_OK) { 94 if (ret == LZMA_STREAM_END) 95 break; 96 97 pr_err("lzma: failed %s\n", lzma_strerror(ret)); 98 goto err_lzma_end; 99 } 100 } 101 102 err = 0; 103 err_lzma_end: 104 lzma_end(&strm); 105 err_fclose: 106 fclose(infile); 107 return err; 108 } 109 110 bool lzma_is_compressed(const char *input) 111 { 112 int fd = open(input, O_RDONLY); 113 const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 }; 114 char buf[6] = { 0 }; 115 ssize_t rc; 116 117 if (fd < 0) 118 return -1; 119 120 rc = read(fd, buf, sizeof(buf)); 121 close(fd); 122 return rc == sizeof(buf) ? 123 memcmp(buf, magic, sizeof(buf)) == 0 : false; 124 } 125