mtd: add fixwrg command

Add a command to fix WRG headers, based on wrgg.c.

Signed-off-by: George Hopkins <george-hopkins@null.net>

package/system/mtd/src/Makefile

@@ -4,6 +4,7 @@ LDFLAGS += -lubox
 
 obj = mtd.o jffs2.o crc32.o md5.o
 obj.seama = seama.o md5.o
+obj.wrg = wrg.o md5.o
 obj.wrgg = wrgg.o md5.o
 obj.ar71xx = trx.o $(obj.seama) $(obj.wrgg)
 obj.brcm = trx.o

package/system/mtd/src/mtd.c

@@ -54,6 +54,7 @@
 
 #define TRX_MAGIC		0x48445230	/* "HDR0" */
 #define SEAMA_MAGIC		0x5ea3a417
+#define WRG_MAGIC		0x20040220
 #define WRGG03_MAGIC		0x20080321
 
 #if !defined(__BYTE_ORDER)
@@ -76,6 +77,7 @@ enum mtd_image_format {
 	MTD_IMAGE_FORMAT_UNKNOWN,
 	MTD_IMAGE_FORMAT_TRX,
 	MTD_IMAGE_FORMAT_SEAMA,
+	MTD_IMAGE_FORMAT_WRG,
 	MTD_IMAGE_FORMAT_WRGG03,
 };
 
@@ -205,6 +207,8 @@ image_check(int imagefd, const char *mtd)
 		imageformat = MTD_IMAGE_FORMAT_TRX;
 	else if (be32_to_cpu(magic) == SEAMA_MAGIC)
 		imageformat = MTD_IMAGE_FORMAT_SEAMA;
+	else if (le32_to_cpu(magic) == WRG_MAGIC)
+		imageformat = MTD_IMAGE_FORMAT_WRG;
 	else if (le32_to_cpu(magic) == WRGG03_MAGIC)
 		imageformat = MTD_IMAGE_FORMAT_WRGG03;
 
@@ -214,7 +218,7 @@ image_check(int imagefd, const char *mtd)
 			ret = trx_check(imagefd, mtd, buf, &buflen);
 		break;
 	case MTD_IMAGE_FORMAT_SEAMA:
-		break;
+	case MTD_IMAGE_FORMAT_WRG:
 	case MTD_IMAGE_FORMAT_WRGG03:
 		break;
 	default:
@@ -685,6 +689,10 @@ resume:
 			if (mtd_fixseama)
 				mtd_fixseama(mtd, 0, 0);
 			break;
+		case MTD_IMAGE_FORMAT_WRG:
+			if (mtd_fixwrg)
+				mtd_fixwrg(mtd, 0, 0);
+			break;
 		case MTD_IMAGE_FORMAT_WRGG03:
 			if (mtd_fixwrgg)
 				mtd_fixwrgg(mtd, 0, 0);
@@ -734,6 +742,10 @@ static void usage(void)
 	    fprintf(stderr,
 	"        fixseama                fix the checksum in a seama header on first boot\n");
 	}
+	if (mtd_fixwrg) {
+	    fprintf(stderr,
+	"        fixwrg                  fix the checksum in a wrg header on first boot\n");
+	}
 	if (mtd_fixwrgg) {
 	    fprintf(stderr,
 	"        fixwrgg                 fix the checksum in a wrgg header on first boot\n");
@@ -755,9 +767,9 @@ static void usage(void)
 	    fprintf(stderr,
 	"        -o offset               offset of the image header in the partition(for fixtrx)\n");
 	}
-	if (mtd_fixtrx || mtd_fixseama || mtd_fixwrgg) {
+	if (mtd_fixtrx || mtd_fixseama || mtd_fixwrg || mtd_fixwrgg) {
 		fprintf(stderr,
-	"        -c datasize             amount of data to be used for checksum calculation (for fixtrx / fixseama / fixwrgg)\n");
+	"        -c datasize             amount of data to be used for checksum calculation (for fixtrx / fixseama / fixwrg / fixwrgg)\n");
 	}
 	fprintf(stderr,
 #ifdef FIS_SUPPORT
@@ -798,6 +810,7 @@ int main (int argc, char **argv)
 		CMD_JFFS2WRITE,
 		CMD_FIXTRX,
 		CMD_FIXSEAMA,
+		CMD_FIXWRG,
 		CMD_FIXWRGG,
 		CMD_VERIFY,
 		CMD_DUMP,
@@ -913,6 +926,9 @@ int main (int argc, char **argv)
 	} else if (((strcmp(argv[0], "fixseama") == 0) && (argc == 2)) && mtd_fixseama) {
 		cmd = CMD_FIXSEAMA;
 		device = argv[1];
+	} else if (((strcmp(argv[0], "fixwrg") == 0) && (argc == 2)) && mtd_fixwrg) {
+		cmd = CMD_FIXWRG;
+		device = argv[1];
 	} else if (((strcmp(argv[0], "fixwrgg") == 0) && (argc == 2)) && mtd_fixwrgg) {
 		cmd = CMD_FIXWRGG;
 		device = argv[1];
@@ -1012,6 +1028,10 @@ int main (int argc, char **argv)
 			if (mtd_fixseama)
 				mtd_fixseama(device, 0, data_size);
 			break;
+		case CMD_FIXWRG:
+			if (mtd_fixwrg)
+				mtd_fixwrg(device, 0, data_size);
+			break;
 		case CMD_FIXWRGG:
 			if (mtd_fixwrgg)
 				mtd_fixwrgg(device, 0, data_size);

package/system/mtd/src/mtd.h

@@ -27,6 +27,7 @@ extern int trx_fixup(int fd, const char *name)  __attribute__ ((weak));
 extern int trx_check(int imagefd, const char *mtd, char *buf, int *len) __attribute__ ((weak));
 extern int mtd_fixtrx(const char *mtd, size_t offset, size_t data_size) __attribute__ ((weak));
 extern int mtd_fixseama(const char *mtd, size_t offset, size_t data_size) __attribute__ ((weak));
+extern int mtd_fixwrg(const char *mtd, size_t offset, size_t data_size) __attribute__ ((weak));
 extern int mtd_fixwrgg(const char *mtd, size_t offset, size_t data_size) __attribute__ ((weak));
 extern int mtd_resetbc(const char *mtd) __attribute__ ((weak));
 #endif /* __mtd_h */

package/system/mtd/src/wrg.c

@@ -0,0 +1,208 @@
+/*
+ * wrg.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>
+ * Copyright (C) 2017 George Hopkins <george-hopkins@null.net>
+ *
+ * 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 <byteswap.h>
+#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 "md5.h"
+
+#if !defined(__BYTE_ORDER)
+#error "Unknown byte order"
+#endif
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define cpu_to_le32(x)	bswap_32(x)
+#define le32_to_cpu(x)	bswap_32(x)
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+#define cpu_to_le32(x)	(x)
+#define le32_to_cpu(x)	(x)
+#else
+#error "Unsupported endianness"
+#endif
+
+#define WRG_MAGIC	0x20040220
+
+struct wrg_header {
+	char		signature[32];
+	uint32_t	magic1;
+	uint32_t	magic2;
+	uint32_t	size;
+	uint32_t	offset;
+	char		devname[32];
+	char		digest[16];
+} __attribute__ ((packed));
+
+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
+wrg_fix_md5(struct wrg_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->devname, sizeof(shdr->devname));
+	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 = cpu_to_le32(data_size);
+
+	/* update the checksum in the image */
+	memcpy(shdr->digest, digest, sizeof(digest));
+
+err_free:
+	free(buf);
+err_out:
+	return err;
+}
+
+int
+mtd_fixwrg(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 wrg_header *shdr;
+
+	if (quiet < 2)
+		fprintf(stderr, "Trying to fix WRG 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 wrg_header *)(first_block + offset);
+	if (le32_to_cpu(shdr->magic1) != WRG_MAGIC) {
+		fprintf(stderr, "No WRG header found (%08x != %08x)\n",
+		        le32_to_cpu(shdr->magic1), WRG_MAGIC);
+		exit(1);
+	} else if (!le32_to_cpu(shdr->size)) {
+		fprintf(stderr, "WRG entity with empty image\n");
+		exit(1);
+	}
+
+	data_offset = offset + sizeof(struct wrg_header);
+	if (!data_size)
+		data_size = mtdsize - data_offset;
+	if (data_size > le32_to_cpu(shdr->size))
+		data_size = le32_to_cpu(shdr->size);
+	if (wrg_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;
+}