123 lines · c
1// SPDX-License-Identifier: GPL-2.02#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 819216 17static 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 35int 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_debug("lzma: fopen failed on %s: '%s'\n", 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_debug("lzma: lzma_stream_decoder failed %s (%d)\n", lzma_strerror(ret), ret);55 goto err_fclose;56 }57 58 strm.next_in = NULL;59 strm.avail_in = 0;60 strm.next_out = buf_out;61 strm.avail_out = sizeof(buf_out);62 63 while (1) {64 if (strm.avail_in == 0 && !feof(infile)) {65 strm.next_in = buf_in;66 strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);67 68 if (ferror(infile)) {69 pr_debug("lzma: read error: %s\n", strerror(errno));70 goto err_lzma_end;71 }72 73 if (feof(infile))74 action = LZMA_FINISH;75 }76 77 ret = lzma_code(&strm, action);78 79 if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {80 ssize_t write_size = sizeof(buf_out) - strm.avail_out;81 82 if (writen(output_fd, buf_out, write_size) != write_size) {83 pr_debug("lzma: write error: %s\n", strerror(errno));84 goto err_lzma_end;85 }86 87 strm.next_out = buf_out;88 strm.avail_out = sizeof(buf_out);89 }90 91 if (ret != LZMA_OK) {92 if (ret == LZMA_STREAM_END)93 break;94 95 pr_debug("lzma: failed %s\n", lzma_strerror(ret));96 goto err_lzma_end;97 }98 }99 100 err = 0;101err_lzma_end:102 lzma_end(&strm);103err_fclose:104 fclose(infile);105 return err;106}107 108bool lzma_is_compressed(const char *input)109{110 int fd = open(input, O_RDONLY);111 const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };112 char buf[6] = { 0 };113 ssize_t rc;114 115 if (fd < 0)116 return -1;117 118 rc = read(fd, buf, sizeof(buf));119 close(fd);120 return rc == sizeof(buf) ?121 memcmp(buf, magic, sizeof(buf)) == 0 : false;122}123