X-Git-Url: https://git.rohieb.name/openwrt.git/blobdiff_plain/82cd54f3ea9325bbd7958526f261ef6121896270..2d3d3c4f6e44013824247928605c5d9439a3b564:/package/mtd/src/trx.c

diff --git a/package/mtd/src/trx.c b/package/mtd/src/trx.c
index 5457a365b..b8d9e2bf0 100644
--- a/package/mtd/src/trx.c
+++ b/package/mtd/src/trx.c
@@ -1,7 +1,7 @@
 /*
  * trx.c
  *
- * Copyright (C) 2005 Mike Baker 
+ * Copyright (C) 2005 Mike Baker
  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
  *
  * This program is free software; you can redistribute it and/or
@@ -27,52 +27,32 @@
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <string.h>
+#include <errno.h>
 
 #include <sys/ioctl.h>
 #include "mtd-api.h"
 #include "mtd.h"
+#include "crc32.h"
 
 #define TRX_MAGIC       0x30524448      /* "HDR0" */
 struct trx_header {
-	unsigned magic;		/* "HDR0" */
-	unsigned len;		/* Length of file including header */
-	unsigned crc32;		/* 32-bit CRC from flag_version to end of file */
-	unsigned flag_version;	/* 0:15 flags, 16:31 version */
-	unsigned offsets[3];	/* Offsets of partitions from start of header */
+	uint32_t magic;		/* "HDR0" */
+	uint32_t len;		/* Length of file including header */
+	uint32_t crc32;		/* 32-bit CRC from flag_version to end of file */
+	uint32_t flag_version;	/* 0:15 flags, 16:31 version */
+	uint32_t offsets[3];    /* Offsets of partitions from start of header */
 };
 
-static unsigned long *crc32 = NULL;
+#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
 
-static void init_crc32()
-{
-	unsigned long crc;
-	unsigned long poly = 0xEDB88320L;
-	int n, bit;
-
-	if (crc32)
-		return;
-
-	crc32 = (unsigned long *) malloc(256 * sizeof(unsigned long));
-	if (!crc32) {
-		perror("malloc");
-		exit(1);
-	}
-
-	for (n = 0; n < 256; n++) {
-		crc = (unsigned long) n;
-		for (bit = 0; bit < 8; bit++)
-			crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
-		crc32[n] = crc;
-	}
-}
-
-static unsigned int crc32buf(char *buf, size_t len)
-{
-	unsigned int crc = 0xFFFFFFFF;
-	for (; len; len--, buf++)
-		crc = crc32[(crc ^ *buf) & 0xff] ^ (crc >> 8);
-	return crc;
-}
+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
 trx_fixup(int fd, const char *name)
@@ -107,7 +87,6 @@ trx_fixup(int fd, const char *name)
 		goto err;
 	}
 
-	init_crc32();
 	scan = ptr + offsetof(struct trx_header, flag_version);
 	trx->crc32 = crc32buf(scan, trx->len - (scan - ptr));
 	msync(ptr, sizeof(struct trx_header), MS_SYNC|MS_INVALIDATE);
@@ -163,3 +142,79 @@ trx_check(int imagefd, const char *mtd, char *buf, int *len)
 	return 1;
 }
 
+int
+mtd_fixtrx(const char *mtd, size_t offset)
+{
+	int fd;
+	struct trx_header *trx;
+	char *buf;
+	ssize_t res;
+	size_t block_offset;
+
+	if (quiet < 2)
+		fprintf(stderr, "Trying to fix trx 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);
+	}
+
+	buf = malloc(erasesize);
+	if (!buf) {
+		perror("malloc");
+		exit(1);
+	}
+
+	res = pread(fd, buf, erasesize, block_offset);
+	if (res != erasesize) {
+		perror("pread");
+		exit(1);
+	}
+
+	trx = (struct trx_header *) (buf + offset);
+	if (trx->magic != STORE32_LE(0x30524448)) {
+		fprintf(stderr, "No trx magic found\n");
+		exit(1);
+	}
+
+	if (trx->len == STORE32_LE(erasesize - offset)) {
+		if (quiet < 2)
+			fprintf(stderr, "Header already fixed, exiting\n");
+		close(fd);
+		return 0;
+	}
+
+	trx->len = STORE32_LE(erasesize - offset);
+
+	trx->crc32 = STORE32_LE(crc32buf((char*) &trx->flag_version, erasesize - offset - 3*4));
+	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, "New crc32: 0x%x, rewriting block\n", trx->crc32);
+
+	if (pwrite(fd, buf, erasesize, block_offset) != erasesize) {
+		fprintf(stderr, "Error writing block (%s)\n", strerror(errno));
+		exit(1);
+	}
+
+	if (quiet < 2)
+		fprintf(stderr, "Done.\n");
+
+	close (fd);
+	sync();
+	return 0;
+
+}
+