tools/perf/util/lzma.c

   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 }