dospart: recover and convert to mount function

modules/dospart.c

@@ -0,0 +1,140 @@
+/* vim: tabstop=4 shiftwidth=4 noexpandtab
+ * This file is part of ToaruOS and is released under the terms
+ * of the NCSA / University of Illinois License - see LICENSE.md
+ * Copyright (C) 2014-2018 K. Lange
+ */
+#include <kernel/types.h>
+#include <kernel/module.h>
+#include <kernel/vfs.h>
+#include <kernel/printf.h>
+#include <kernel/tokenize.h>
+
+#define SECTORSIZE      512
+
+typedef struct {
+	uint8_t  status;
+	uint8_t  chs_first_sector[3];
+	uint8_t  type;
+	uint8_t  chs_last_sector[3];
+	uint32_t lba_first_sector;
+	uint32_t sector_count;
+} partition_t;
+
+typedef struct {
+	uint8_t     boostrap[446];
+	partition_t partitions[4];
+	uint8_t     signature[2];
+} __attribute__((packed)) mbr_t;
+
+struct dos_partition_entry {
+	fs_node_t * device;
+	partition_t partition;
+};
+
+static ssize_t read_part(fs_node_t *node, off_t offset, size_t size, uint8_t *buffer) {
+	struct dos_partition_entry * device = (struct dos_partition_entry *)node->device;
+
+	if ((size_t)offset > device->partition.sector_count * SECTORSIZE) {
+		return 0;
+	}
+
+	if (offset + size > device->partition.sector_count * SECTORSIZE) {
+		size = device->partition.sector_count * SECTORSIZE - offset;
+	}
+
+	return read_fs(device->device, offset + device->partition.lba_first_sector * SECTORSIZE, size, buffer);
+}
+
+static ssize_t write_part(fs_node_t *node, off_t offset, size_t size, uint8_t *buffer) {
+	struct dos_partition_entry * device = (struct dos_partition_entry *)node->device;
+
+	if ((size_t)offset > device->partition.sector_count * SECTORSIZE) {
+		return 0;
+	}
+
+	if (offset + size > device->partition.sector_count * SECTORSIZE) {
+		size = device->partition.sector_count * SECTORSIZE - offset;
+	}
+
+	return write_fs(device->device, offset + device->partition.lba_first_sector * SECTORSIZE, size, buffer);
+}
+
+static void open_part(fs_node_t * node, unsigned int flags) {
+	return;
+}
+
+static void close_part(fs_node_t * node) {
+	return;
+}
+
+static fs_node_t * dospart_device_create(int i, fs_node_t * dev, mbr_t * mbr, int id) {
+
+	vfs_lock(dev);
+
+	struct dos_partition_entry * device = malloc(sizeof(struct dos_partition_entry));
+	memcpy(&device->partition, &mbr->partitions[id], sizeof(partition_t));
+	device->device = dev;
+
+	fs_node_t * fnode = malloc(sizeof(fs_node_t));
+	memset(fnode, 0x00, sizeof(fs_node_t));
+	fnode->inode = 0;
+	snprintf(fnode->name, 20, "dospart%d", i);
+	fnode->device  = device;
+	fnode->uid = 0;
+	fnode->gid = 0;
+	fnode->mask    = 0660;
+	fnode->length  = device->partition.sector_count * SECTORSIZE; /* TODO */
+	fnode->flags   = FS_BLOCKDEVICE;
+	fnode->read    = read_part;
+	fnode->write   = write_part;
+	fnode->open    = open_part;
+	fnode->close   = close_part;
+	fnode->readdir = NULL;
+	fnode->finddir = NULL;
+	fnode->ioctl   = NULL; /* TODO, identify, etc? */
+	return fnode;
+}
+
+static fs_node_t * dospart_map(const char * device, const char * mount_path) {
+	char * arg = strdup(device);
+	char * argv[10];
+	tokenize(arg, ",", argv);
+
+	fs_node_t * dev = kopen(argv[0], 0);
+	if (!dev) {
+		return NULL;
+	}
+
+	mbr_t mbr;
+	read_fs(dev, 0, SECTORSIZE, (uint8_t *)&mbr);
+
+	if (mbr.signature[0] == 0x55 && mbr.signature[1] == 0xAA) {
+		for (int i = 0; i < 4; ++i) {
+			if (mbr.partitions[i].status & 0x80) {
+				fs_node_t * node = dospart_device_create(i, dev, &mbr, i);
+				char tmp[64];
+				snprintf(tmp, 20, "%s%d", device, i);
+				vfs_mount(tmp, node);
+			}
+		}
+	}
+
+	/* VFS_MOUNT_PARTITION_MAPPER_SUCCESS? */
+	return (fs_node_t*)1;
+}
+
+static int dospart_initialize(int argc, char * argv[]) {
+	vfs_register("mbr", dospart_map);
+	return 0;
+}
+
+static int dospart_finalize(void) {
+	return 0;
+}
+
+struct Module metadata = {
+	.name = "dospart",
+	.init = dospart_initialize,
+	.fini = dospart_finalize,
+};
+