extract all files from the firmware image.

[rsbs2] / extract.c

#include <sys/stat.h>
#include <sys/types.h>
#include <limits.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <libgen.h>
#include "rsb-lz.h"
#include "extract.h"

void extract_files(unsigned char *fw, int len)
{
	unsigned char *pos;
	unsigned int type, length;
	char *name;

	pos = fw + 0x28;
	printf("Start of filesystem: 0x%08x\n", *((unsigned int*)pos));

	pos = fw + *((unsigned int*)pos);

	while (pos < (fw + len)) {
		type = *((unsigned int*)pos);
		pos += 4;
		/* ??? */
		pos++;
		length = *((unsigned int*)pos);
		pos += 4;
		name = (char*)pos;
		pos += strlen(name) + 1;

		if ((pos + length) > (fw + len)) {
			printf("EOF reached\n");
			break;
		}
		printf("%s: type: 0x%x, length: %d", name, type, length);

		if (length > 0) {
			write_file(name, pos, length);
			if (*((unsigned int*)pos) == LZ_MAGIC) {
				char *lzname;

				if ((lzname = strdup(name)) == NULL) {
					perror("strdup");
					exit(1);
				}

				if (!strcmp(lzname + strlen(lzname) - 4 , ".lz")) {
					fprintf(stderr, "Ugh, can't derive filename...\n");
					exit(1);
				}
				lzname[strlen(lzname) - 3] = 0x00;

				printf("%s: packed file found", lzname);

				extract_lz_file(pos, (unsigned char*)lzname);
				free(lzname);
			} else if (!strcmp(name, "firmware")) {
				unsigned char *lzpos;
				char lzname[128];

				bzero(lzname, sizeof(lzname));
				strcpy(lzname, "firmware.");

				lzpos = pos + *((unsigned int*)(pos + 0x20));
				memcpy(lzname + strlen(lzname), lzpos - 4, 4);
				lzpos += 4;
				if (*((unsigned int*)(lzpos)) == LZ_MAGIC) {
					printf("%s: compressed firmware part found", lzname);
					extract_lz_file(lzpos, (unsigned char*)lzname);
				}
			}
		}

		pos += length;

	}
}

void mkdir_p(char *dir)
{
	char *copy, *parent;

	if ((dir == NULL) || (!strcmp(dir, ".")))
		return;

	if ((copy = strdup(dir)) == NULL) {
		perror("strdup");
		exit(1);
	}
	parent = dirname(copy);
	mkdir_p(parent);

	errno = 0;
	if (mkdir(dir, 0755) == -1) {
		if (errno != EEXIST) {
			fprintf(stderr, "%s: ", dir);
			perror("mkdir");
			exit(1);
		}
	}
	free(copy);
}

void write_file(char *fname, unsigned char *buf, int len)
{
	char filename[PATH_MAX];
	char *filename_c, *dirn;
	int fd;
	int remaining;
	int ret;

	strcpy(filename, "extracted/");
	strcat(filename, fname);

	if ((filename_c = strdup(filename)) == NULL) {
		perror("strdup");
		exit(1);
	}
	dirn = dirname(filename_c);
	mkdir_p(dirn);
	free(filename_c);

	if ((fd = open(filename, O_WRONLY|O_CREAT, 0644)) == -1) {
		fprintf(stderr, "%s: ", filename);
		perror("open");
		exit(1);
	}

	remaining = len;

	while(remaining) {
		ret = write(fd, buf + (len - remaining), remaining);
		if (ret < 0) {
			perror("write");
			exit(1);
		}
		remaining -= ret;
	}

	printf(", %s written.\n", filename);

	close(fd);
}