perf/util/lzma.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <errno.h>
0003 #include <lzma.h>
0004 #include <stdio.h>
0005 #include <linux/compiler.h>
0006 #include <sys/types.h>
0007 #include <sys/stat.h>
0008 #include <fcntl.h>
0009 #include "compress.h"
0010 #include "debug.h"
0011 #include <string.h>
0012 #include <unistd.h>
0013 #include <internal/lib.h>
0014
0015 #define BUFSIZE 8192
0016
0017 static const char *lzma_strerror(lzma_ret ret)
0018 {
0019     switch ((int) ret) {
0020     case LZMA_MEM_ERROR:
0021         return "Memory allocation failed";
0022     case LZMA_OPTIONS_ERROR:
0023         return "Unsupported decompressor flags";
0024     case LZMA_FORMAT_ERROR:
0025         return "The input is not in the .xz format";
0026     case LZMA_DATA_ERROR:
0027         return "Compressed file is corrupt";
0028     case LZMA_BUF_ERROR:
0029         return "Compressed file is truncated or otherwise corrupt";
0030     default:
0031         return "Unknown error, possibly a bug";
0032     }
0033 }
0034
0035 int lzma_decompress_to_file(const char *input, int output_fd)
0036 {
0037     lzma_action action = LZMA_RUN;
0038     lzma_stream strm   = LZMA_STREAM_INIT;
0039     lzma_ret ret;
0040     int err = -1;
0041
0042     u8 buf_in[BUFSIZE];
0043     u8 buf_out[BUFSIZE];
0044     FILE *infile;
0045
0046     infile = fopen(input, "rb");
0047     if (!infile) {
0048         pr_err("lzma: fopen failed on %s: '%s'\n",
0049                input, strerror(errno));
0050         return -1;
0051     }
0052
0053     ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
0054     if (ret != LZMA_OK) {
0055         pr_err("lzma: lzma_stream_decoder failed %s (%d)\n",
0056             lzma_strerror(ret), ret);
0057         goto err_fclose;
0058     }
0059
0060     strm.next_in   = NULL;
0061     strm.avail_in  = 0;
0062     strm.next_out  = buf_out;
0063     strm.avail_out = sizeof(buf_out);
0064
0065     while (1) {
0066         if (strm.avail_in == 0 && !feof(infile)) {
0067             strm.next_in  = buf_in;
0068             strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);
0069
0070             if (ferror(infile)) {
0071                 pr_err("lzma: read error: %s\n", strerror(errno));
0072                 goto err_lzma_end;
0073             }
0074
0075             if (feof(infile))
0076                 action = LZMA_FINISH;
0077         }
0078
0079         ret = lzma_code(&strm, action);
0080
0081         if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
0082             ssize_t write_size = sizeof(buf_out) - strm.avail_out;
0083
0084             if (writen(output_fd, buf_out, write_size) != write_size) {
0085                 pr_err("lzma: write error: %s\n", strerror(errno));
0086                 goto err_lzma_end;
0087             }
0088
0089             strm.next_out  = buf_out;
0090             strm.avail_out = sizeof(buf_out);
0091         }
0092
0093         if (ret != LZMA_OK) {
0094             if (ret == LZMA_STREAM_END)
0095                 break;
0096
0097             pr_err("lzma: failed %s\n", lzma_strerror(ret));
0098             goto err_lzma_end;
0099         }
0100     }
0101
0102     err = 0;
0103 err_lzma_end:
0104     lzma_end(&strm);
0105 err_fclose:
0106     fclose(infile);
0107     return err;
0108 }
0109
0110 bool lzma_is_compressed(const char *input)
0111 {
0112     int fd = open(input, O_RDONLY);
0113     const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };
0114     char buf[6] = { 0 };
0115     ssize_t rc;
0116
0117     if (fd < 0)
0118         return -1;
0119
0120     rc = read(fd, buf, sizeof(buf));
0121     close(fd);
0122     return rc == sizeof(buf) ?
0123            memcmp(buf, magic, sizeof(buf)) == 0 : false;
0124 }