mtd: add fixwrgg command

Based on fixseama.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Acked-by: John Crispin <john@phrozen.org>

1 files changed, 190 insertions, 0 deletions

diff --git a/package/system/mtd/src/wrgg.c b/package/system/mtd/src/wrgg.c
new file mode 100644
index 0000000000..e0b5ca172d
--- /dev/null
+++ b/package/system/mtd/src/wrgg.c
@@ -0,0 +1,190 @@
+/*
+ * wrgg.c
+ *
+ * Copyright (C) 2005 Mike Baker
+ * Copyright (C) 2008 Felix Fietkau <nbd@nbd.name>
+ * Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2016 Stijn Tintel <stijn@linux-ipv6.be>
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <endian.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+
+#include <sys/ioctl.h>
+#include <mtd/mtd-user.h>
+#include "mtd.h"
+#include "wrgg.h"
+#include "md5.h"
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define STORE32_LE(X)           ((((X) & 0x000000FF) << 24) | (((X) & 0x0000FF00) << 8) | (((X) & 0x00FF0000) >> 8) | (((X) & 0xFF000000) >> 24))
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+#define STORE32_LE(X)           (X)
+#else
+#error unknown endianness!
+#endif
+
+ssize_t pread(int fd, void *buf, size_t count, off_t offset);
+ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
+
+int
+wrgg_fix_md5(struct wrgg03_header *shdr, int fd, size_t data_offset, size_t data_size)
+{
+	char *buf;
+	ssize_t res;
+	MD5_CTX ctx;
+	unsigned char digest[16];
+	int i;
+	int err = 0;
+
+	buf = malloc(data_size);
+	if (!buf) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	res = pread(fd, buf, data_size, data_offset);
+	if (res != data_size) {
+		perror("pread");
+		err = -EIO;
+		goto err_free;
+	}
+
+	MD5_Init(&ctx);
+	MD5_Update(&ctx, (char *)&shdr->offset, sizeof(shdr->offset));
+	MD5_Update(&ctx, (char *)&shdr->dev_name, sizeof(shdr->dev_name));
+	MD5_Update(&ctx, buf, data_size);
+	MD5_Final(digest, &ctx);
+
+	if (!memcmp(digest, shdr->digest, sizeof(digest))) {
+		if (quiet < 2)
+			fprintf(stderr, "the header is fixed already\n");
+		return -1;
+	}
+
+	if (quiet < 2) {
+		fprintf(stderr, "new size:%u, new MD5: ", data_size);
+		for (i = 0; i < sizeof(digest); i++)
+			fprintf(stderr, "%02x", digest[i]);
+
+		fprintf(stderr, "\n");
+	}
+
+	/* update the size in the image */
+	shdr->size = htonl(data_size);
+
+	/* update the checksum in the image */
+	memcpy(shdr->digest, digest, sizeof(digest));
+
+err_free:
+	free(buf);
+err_out:
+	return err;
+}
+
+int
+mtd_fixwrgg(const char *mtd, size_t offset, size_t data_size)
+{
+	int fd;
+	char *first_block;
+	ssize_t res;
+	size_t block_offset;
+	size_t data_offset;
+	struct wrgg03_header *shdr;
+
+	if (quiet < 2)
+		fprintf(stderr, "Trying to fix WRGG header in %s at 0x%x...\n",
+			mtd, offset);
+
+	block_offset = offset & ~(erasesize - 1);
+	offset -= block_offset;
+
+	fd = mtd_check_open(mtd);
+	if(fd < 0) {
+		fprintf(stderr, "Could not open mtd device: %s\n", mtd);
+		exit(1);
+	}
+
+	if (block_offset + erasesize > mtdsize) {
+		fprintf(stderr, "Offset too large, device size 0x%x\n",
+			mtdsize);
+		exit(1);
+	}
+
+	first_block = malloc(erasesize);
+	if (!first_block) {
+		perror("malloc");
+		exit(1);
+	}
+
+	res = pread(fd, first_block, erasesize, block_offset);
+	if (res != erasesize) {
+		perror("pread");
+		exit(1);
+	}
+
+	shdr = (struct wrgg03_header *)(first_block + offset);
+	if (shdr->magic1 != htonl(STORE32_LE(WRGG03_MAGIC))) {
+		fprintf(stderr, "magic1 %x\n", shdr->magic1);
+		fprintf(stderr, "htonl(WRGG03_MAGIC) %x\n", WRGG03_MAGIC);
+		fprintf(stderr, "No WRGG header found\n");
+		exit(1);
+	} else if (!ntohl(shdr->size)) {
+		fprintf(stderr, "WRGG entity with empty image\n");
+		exit(1);
+	}
+
+	data_offset = offset + sizeof(struct wrgg03_header);
+	if (!data_size)
+		data_size = mtdsize - data_offset;
+	if (data_size > ntohl(shdr->size))
+		data_size = ntohl(shdr->size);
+	if (wrgg_fix_md5(shdr, fd, data_offset, data_size))
+		goto out;
+
+	if (mtd_erase_block(fd, block_offset)) {
+		fprintf(stderr, "Can't erease block at 0x%x (%s)\n",
+			block_offset, strerror(errno));
+		exit(1);
+	}
+
+	if (quiet < 2)
+		fprintf(stderr, "Rewriting block at 0x%x\n", block_offset);
+
+	if (pwrite(fd, first_block, erasesize, block_offset) != erasesize) {
+		fprintf(stderr, "Error writing block (%s)\n", strerror(errno));
+		exit(1);
+	}
+
+	if (quiet < 2)
+		fprintf(stderr, "Done.\n");
+
+out:
+	close (fd);
+	sync();
+
+	return 0;
+}