--- /dev/null
+/*
+ * A tool for reading the zlib compressed calibration data
+ * found in AVM Fritz!Box based devices).
+ *
+ * Copyright (c) 2017 Christian Lamparter <chunkeey@googlemail.com>
+ *
+ * Based on zpipe, which is an example of proper use of zlib's inflate().
+ * that is Not copyrighted -- provided to the public domain
+ * Version 1.4 11 December 2005 Mark Adler
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <endian.h>
+#include <errno.h>
+#include "zlib.h"
+
+#define CHUNK 1024
+
+static inline size_t special_min(size_t a, size_t b)
+{
+ return a == 0 ? b : (a < b ? a : b);
+}
+
+/* Decompress from file source to file dest until stream ends or EOF.
+ inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
+ allocated for processing, Z_DATA_ERROR if the deflate data is
+ invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
+ the version of the library linked do not match, or Z_ERRNO if there
+ is an error reading or writing the files. */
+static int inf(FILE *source, FILE *dest, size_t limit, size_t skip)
+{
+ int ret;
+ size_t have;
+ z_stream strm;
+ unsigned char in[CHUNK];
+ unsigned char out[CHUNK];
+
+ /* allocate inflate state */
+ strm.zalloc = Z_NULL;
+ strm.zfree = Z_NULL;
+ strm.opaque = Z_NULL;
+ strm.avail_in = 0;
+ strm.next_in = Z_NULL;
+ ret = inflateInit(&strm);
+ if (ret != Z_OK)
+ return ret;
+
+ /* decompress until deflate stream ends or end of file */
+ do {
+ strm.avail_in = fread(in, 1, CHUNK, source);
+ if (ferror(source)) {
+ (void)inflateEnd(&strm);
+ return Z_ERRNO;
+ }
+ if (strm.avail_in == 0)
+ break;
+ strm.next_in = in;
+
+ /* run inflate() on input until output buffer not full */
+ do {
+ strm.avail_out = CHUNK;
+ strm.next_out = out;
+ ret = inflate(&strm, Z_NO_FLUSH);
+ assert(ret != Z_STREAM_ERROR); /* state not clobbered */
+ switch (ret) {
+ case Z_NEED_DICT:
+ ret = Z_DATA_ERROR; /* and fall through */
+ case Z_DATA_ERROR:
+ case Z_MEM_ERROR:
+ (void)inflateEnd(&strm);
+ return ret;
+ }
+ have = special_min(limit, CHUNK - strm.avail_out) - skip;
+ if (fwrite(&out[skip], have, 1, dest) != 1 || ferror(dest)) {
+ (void)inflateEnd(&strm);
+ return Z_ERRNO;
+ }
+ skip = 0;
+ limit -= have;
+ } while (strm.avail_out == 0 && limit > 0);
+
+ /* done when inflate() says it's done */
+ } while (ret != Z_STREAM_END && limit > 0);
+
+ /* clean up and return */
+ (void)inflateEnd(&strm);
+ return (limit == 0 ? Z_OK : (ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR));
+}
+
+/* report a zlib or i/o error */
+static void zerr(int ret)
+{
+ switch (ret) {
+ case Z_ERRNO:
+ if (ferror(stdin))
+ fputs("error reading stdin\n", stderr);
+ if (ferror(stdout))
+ fputs("error writing stdout\n", stderr);
+ break;
+ case Z_STREAM_ERROR:
+ fputs("invalid compression level\n", stderr);
+ break;
+ case Z_DATA_ERROR:
+ fputs("invalid or incomplete deflate data\n", stderr);
+ break;
+ case Z_MEM_ERROR:
+ fputs("out of memory\n", stderr);
+ break;
+ case Z_VERSION_ERROR:
+ fputs("zlib version mismatch!\n", stderr);
+ }
+}
+
+static unsigned int get_num(char *str)
+{
+ if (!strncmp("0x", str, 2))
+ return strtoul(str+2, NULL, 16);
+ else
+ return strtoul(str, NULL, 10);
+}
+
+static void usage(void)
+{
+ fprintf(stderr, "Usage: fritz_cal_extract [-s seek offset] [-i skip] [-o output file] [-l limit] [infile] -e entry_id\n"
+ "Finds and extracts zlib compressed calibration data in the EVA loader\n");
+ exit(EXIT_FAILURE);
+}
+
+struct cal_entry {
+ uint16_t id;
+ uint16_t len;
+} __attribute__((packed));
+
+/* compress or decompress from stdin to stdout */
+int main(int argc, char **argv)
+{
+ struct cal_entry cal = { .len = 0 };
+ FILE *in = stdin;
+ FILE *out = stdout;
+ size_t limit = 0, skip = 0;
+ int initial_offset = 0;
+ int entry = -1;
+ int ret;
+ int opt;
+
+ while ((opt = getopt(argc, argv, "s:e:o:l:i:")) != -1) {
+ switch (opt) {
+ case 's':
+ initial_offset = (int)get_num(optarg);
+ if (errno) {
+ perror("Failed to parse seek offset");
+ goto out_bad;
+ }
+ break;
+ case 'e':
+ entry = (int) htobe16(get_num(optarg));
+ if (errno) {
+ perror("Failed to entry id");
+ goto out_bad;
+ }
+ break;
+ case 'o':
+ out = fopen(optarg, "w");
+ if (!out) {
+ perror("Failed to create output file");
+ goto out_bad;
+ }
+ break;
+ case 'l':
+ limit = (size_t)get_num(optarg);
+ if (errno) {
+ perror("Failed to parse limit");
+ goto out_bad;
+ }
+ break;
+ case 'i':
+ skip = (size_t)get_num(optarg);
+ if (errno) {
+ perror("Failed to parse skip");
+ goto out_bad;
+ }
+ break;
+ default: /* '?' */
+ usage();
+ }
+ }
+
+ if (entry == -1)
+ usage();
+
+ if (argc > 1 && optind <= argc) {
+ in = fopen(argv[optind], "r");
+ if (!in) {
+ perror("Failed to create output file");
+ goto out_bad;
+ }
+ }
+
+ if (initial_offset) {
+ ret = fseek(in, initial_offset, SEEK_CUR);
+ if (ret) {
+ perror("Failed to seek to calibration table");
+ goto out_bad;
+ }
+ }
+
+ do {
+ ret = fseek(in, be16toh(cal.len), SEEK_CUR);
+ if (feof(in)) {
+ fprintf(stderr, "Reached end of file, but didn't find the matching entry\n");
+ goto out_bad;
+ } else if (ferror(in)) {
+ perror("Failure during seek");
+ goto out_bad;
+ }
+
+ ret = fread(&cal, 1, sizeof cal, in);
+ if (ret != sizeof cal)
+ goto out_bad;
+ } while (entry != cal.id || cal.id == 0xffff);
+
+ if (cal.id == 0xffff) {
+ fprintf(stderr, "Reached end of filesystem, but didn't find the matching entry\n");
+ goto out_bad;
+ }
+
+ ret = inf(in, out, limit, skip);
+ if (ret == Z_OK)
+ goto out;
+
+ zerr(ret);
+
+out_bad:
+ ret = EXIT_FAILURE;
+
+out:
+ fclose(in);
+ fclose(out);
+ return ret;
+}
projects / openwrt / staging / lynxis / omap.git / blobdiff