cal: Added CAL parser from Calvaria

1 files changed, 263 insertions, 0 deletions

diff --git a/src/cal.c b/src/cal.c
new file mode 100644
index 0000000..3a46abd
--- /dev/null
+++ b/src/cal.c
@@ -0,0 +1,263 @@
+/*
+    0xFFFF - Open Free Fiasco Firmware Flasher
+    Copyright (c) 2011  Michael Buesch <mb@bu3sch.de>
+    Copyright (C) 2012  Pali Rohár <pali.rohar@gmail.com>
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+
+*/
+
+/* This is simple CAL parser form Calvaria */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <errno.h>
+#include <string.h>
+
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <linux/fs.h>
+#include <mtd/mtd-user.h>
+
+#include "cal.h"
+
+#define MAX_SIZE	393216
+#define INDEX_LAST	(0xFF + 1)
+#define HDR_MAGIC	"ConF"
+
+struct cal {
+	int fd;
+	ssize_t size;
+	void * mem;
+};
+
+struct header {
+	char magic[4];		/* Magic sequence */
+	uint8_t type;		/* Type number */
+	uint8_t index;		/* Index number */
+	uint16_t flags;		/* Flags */
+	char name[16];		/* Human readable section name */
+	uint32_t length;	/* Payload length */
+	uint32_t datasum;	/* Data CRC32 checksum */
+	uint32_t hdrsum;	/* Header CRC32 checksum */
+} __attribute__((__packed__));
+
+
+int cal_init_file(const char * file, struct cal ** cal_out) {
+
+	int fd = -1;
+	uint64_t blksize = 0;
+	ssize_t size = 0;
+	void * mem = NULL;
+	struct cal * cal = NULL;
+	struct stat st;
+	mtd_info_t mtd_info;
+
+	if ( stat(file, &st) != 0 )
+		return -1;
+
+	fd = open(file, O_RDONLY);
+
+	if ( fd < 0 )
+		return -1;
+
+	if ( S_ISREG(st.st_mode) )
+		size = st.st_size;
+	else if ( S_ISBLK(st.st_mode) ) {
+		if ( ioctl(fd, BLKGETSIZE64, &blksize) != 0 )
+			goto err;
+		if ( blksize > SSIZE_MAX )
+			goto err;
+		size = blksize;
+	} else if ( S_ISCHR(st.st_mode) && major(st.st_rdev) == 90 ) {
+		if ( ioctl(fd, MEMGETINFO, &mtd_info) != 0 )
+			goto err;
+		size = mtd_info.size;
+	} else {
+		goto err;
+	}
+
+	if ( size == 0 || size > MAX_SIZE )
+		goto err;
+
+	mem = malloc(size);
+
+	if ( ! mem )
+		goto err;
+
+	if ( read(fd, mem, size) != size )
+		goto err;
+
+	cal = malloc(sizeof(struct cal));
+
+	if ( ! cal )
+		goto err;
+
+	cal->fd = fd;
+	cal->mem = mem;
+	cal->size = size;
+
+	*cal_out = cal;
+	return 0;
+
+err:
+	close(fd);
+	free(mem);
+	return -1;
+
+}
+
+int cal_init(struct cal ** cal_out) {
+
+	return cal_init_file("/dev/mtd1ro", cal_out);
+
+}
+
+void cal_finish(struct cal * cal) {
+
+	if ( cal ) {
+		free(cal->mem);
+		free(cal);
+	}
+
+}
+
+static uint32_t crc32(uint32_t crc, const void * _data, size_t size) {
+
+	const uint8_t * data = _data;
+	uint8_t value;
+	unsigned int bit;
+	size_t i;
+	const uint32_t poly = 0xEDB88320;
+
+	for ( i = 0; i < size; i++ ) {
+		value = data[i];
+		for ( bit = 8; bit; bit-- ) {
+			if ( (crc & 1) != (value & 1) )
+				crc = (crc >> 1) ^ poly;
+			else
+				crc >>= 1;
+			value >>= 1;
+		}
+	}
+
+	return crc;
+
+}
+
+static int is_header(void *data, size_t size) {
+
+	struct header * hdr = data;
+
+	if ( size < sizeof(struct header) )
+		return 0;
+
+	if ( memcmp(hdr->magic, HDR_MAGIC, sizeof(hdr->magic)) != 0 )
+
+		return 0;
+	return 1;
+
+}
+
+static int64_t find_section(void *start, uint64_t count, int want_index, const char *want_name) {
+
+	int64_t offset = 0, found_offset = -1;
+	uint8_t * data = start;
+	struct header *hdr;
+	char sectname[sizeof(hdr->name) + 1] = { 0, };
+	uint32_t payload_len;
+	int previous_index = -1;
+
+	while ( 1 ) {
+
+		/* Find header start */
+		if ( count < sizeof(struct header) )
+			break;
+
+		if ( ! is_header(data + offset, count) ) {
+			count--;
+			offset++;
+			continue;
+		}
+
+		hdr = (struct header *)(data + offset);
+		payload_len = hdr->length;
+
+		if ( count - sizeof(struct header) < payload_len )
+			return -1;
+
+		memcpy(sectname, hdr->name, sizeof(hdr->name));
+
+		if ( want_index == INDEX_LAST ) {
+			if ((int)hdr->index <= previous_index)
+				goto next;
+		} else {
+			if (want_index >= 0 && want_index != hdr->index)
+				goto next;
+		}
+
+		if ( want_name && strcmp(sectname, want_name) != 0 )
+			goto next;
+
+		/* Found it */
+		found_offset = offset;
+		if ( want_index == INDEX_LAST )
+			previous_index = hdr->index;
+		else
+			break;
+
+next:
+		count -= sizeof(struct header) + payload_len;
+		offset += sizeof(struct header) + payload_len;
+
+	}
+
+	return found_offset;
+
+}
+
+int cal_read_block(struct cal * cal, const char * name, void ** ptr, unsigned long * len, unsigned long flags) {
+
+	int64_t find_offset;
+	uint64_t filelen = cal->size;
+	uint8_t * data = cal->mem;
+	struct header * hdr;
+
+	find_offset = find_section(data, filelen, INDEX_LAST, name);
+	if ( find_offset < 0 )
+		return -1;
+
+	hdr = (struct header *)(data + find_offset);
+
+	if ( flags && hdr->flags != flags )
+		return -1;
+
+	if ( crc32(0, hdr, sizeof(*hdr) - 4) != hdr->hdrsum )
+		return -1;
+
+	*ptr = data + find_offset + sizeof(struct header);
+	*len = hdr->length;
+
+	if ( crc32(0, *ptr, *len) != hdr->datasum )
+		return -1;
+
+	return 0;
+
+}