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_stream_to_file(FILE *infile, 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 45 ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED); 46 if (ret != LZMA_OK) { 47 pr_debug("lzma: lzma_stream_decoder failed %s (%d)\n", lzma_strerror(ret), ret); 48 return err; 49 } 50 51 strm.next_in = NULL; 52 strm.avail_in = 0; 53 strm.next_out = buf_out; 54 strm.avail_out = sizeof(buf_out); 55 56 while (1) { 57 if (strm.avail_in == 0 && !feof(infile)) { 58 strm.next_in = buf_in; 59 strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile); 60 61 if (ferror(infile)) { 62 pr_debug("lzma: read error: %s\n", strerror(errno)); 63 goto err_lzma_end; 64 } 65 66 if (feof(infile)) 67 action = LZMA_FINISH; 68 } 69 70 ret = lzma_code(&strm, action); 71 72 if (strm.avail_out == 0 || ret == LZMA_STREAM_END) { 73 ssize_t write_size = sizeof(buf_out) - strm.avail_out; 74 75 if (writen(output_fd, buf_out, write_size) != write_size) { 76 pr_debug("lzma: write error: %s\n", strerror(errno)); 77 goto err_lzma_end; 78 } 79 80 strm.next_out = buf_out; 81 strm.avail_out = sizeof(buf_out); 82 } 83 84 if (ret != LZMA_OK) { 85 if (ret == LZMA_STREAM_END) 86 break; 87 88 pr_debug("lzma: failed %s\n", lzma_strerror(ret)); 89 goto err_lzma_end; 90 } 91 } 92 93 err = 0; 94 err_lzma_end: 95 lzma_end(&strm); 96 return err; 97 } 98 99 int lzma_decompress_to_file(const char *input, int output_fd) 100 { 101 FILE *infile; 102 int ret; 103 104 infile = fopen(input, "rb"); 105 if (!infile) { 106 pr_debug("lzma: fopen failed on %s: '%s'\n", input, strerror(errno)); 107 return -1; 108 } 109 110 ret = lzma_decompress_stream_to_file(infile, output_fd); 111 fclose(infile); 112 return ret; 113 } 114 115 bool lzma_is_compressed(const char *input) 116 { 117 int fd = open(input, O_RDONLY); 118 const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 }; 119 char buf[6] = { 0 }; 120 ssize_t rc; 121 122 if (fd < 0) 123 return -1; 124 125 rc = read(fd, buf, sizeof(buf)); 126 close(fd); 127 return rc == sizeof(buf) ? 128 memcmp(buf, magic, sizeof(buf)) == 0 : false; 129 } 130