gptman: add files

8 files changed, 431 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..178ff6e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/gptman
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..6d142c0
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# gptman
+
+gptman is an utility to manage GPT volumes.
\ No newline at end of file
diff --git a/convert/convert.ha b/convert/convert.ha
new file mode 100644
index 0000000..10f73c7
--- /dev/null
+++ b/convert/convert.ha
@@ -0,0 +1,33 @@
+use fmt;
+
+use mbr;
+use gpt;
+use sector;
+
+use os;
+use io;
+use fs;
+use strings;
+use errors;
+
+
+export fn convert(args: []str) void = {
+	if (len(args) < 2) {
+		fmt::fatalf("gptman.convert: needs disk");
+	};
+
+	fmt::println(args[1])!;
+	let file = os::open(args[1], fs::flags::RDWR)!;
+	defer io::close(file)!;
+
+	let vol = gpt::from(file)!;
+	gpt::mkbackup(vol);
+	defer {
+		gpt::chksums(vol);
+		gpt::commit(vol);
+		gpt::finish(vol);
+	};
+
+	vol.primary.header.disk_guid[0] = 0xcafebabe;
+	vol.primary.header.disk_guid[1] = 0xabababababababab;
+};
diff --git a/gpt/crc32.ha b/gpt/crc32.ha
new file mode 100644
index 0000000..24318bd
--- /dev/null
+++ b/gpt/crc32.ha
@@ -0,0 +1,81 @@
+// crc32 polynomial used by the gpt specification
+const crc_table: [256]u32 = [  
+	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
+	0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
+	0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
+	0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
+	0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+	0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
+	0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+	0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
+	0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
+	0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
+	0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
+	0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
+	0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
+	0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+	0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
+	0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
+	0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+	0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
+	0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
+	0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
+	0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
+	0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
+	0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
+	0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+	0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
+	0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
+	0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+	0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
+	0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
+	0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
+	0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
+	0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
+	0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
+	0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+	0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
+	0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
+	0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+	0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
+	0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
+	0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
+	0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
+	0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
+	0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
+	0x2d02ef8d
+];
+
+// Calculates the crc32 header checksum
+export fn header_crc32(self: *header) u32 = {
+	const data = self: *[*]u8;
+	
+	let crc: u32 = 0xffffffff;
+	for (let i = 0z; i < 0x5c; i += 1) {
+		let d: u8 = data[i];
+
+		// set current byte to 0 or skip them if it's the checksum
+		// or the reserved bytes
+		if (i >= 0x10 && i < 0x14) {
+			d = 0;
+		};
+		if (i >= 0x14 && i < 0x18) {
+			d = 0;
+		};
+
+		
+		let lookup_index: u32 = (crc ^ d) & 0xff;
+		crc = (crc >> 8) ^ crc_table[lookup_index];
+	};
+
+	crc ^= 0xffffffff;
+	return crc;
+};
diff --git a/gpt/gpt.ha b/gpt/gpt.ha
new file mode 100644
index 0000000..e1ebcfd
--- /dev/null
+++ b/gpt/gpt.ha
@@ -0,0 +1,197 @@
+use errors;
+use io;
+use types;
+use rt;
+use fmt;
+
+use mbr;
+use sector;
+
+export type nogpt = !void;
+
+export type gpt = struct {
+	mbr_sec: sector::sector,
+	mbr: *mbr::mbr,
+	primary: block,
+	backup: block
+};
+
+export type block = struct {
+	header_sec: sector::sector,
+	entries_sec: sector::sector,
+	header: *header,
+	entries: *[128]entry
+};
+
+fn block_getheader(self: *block) *header = {
+	return self.header_sec.buf: *[*]u8: *header;
+};
+
+fn block_getentries(self: *block) []entry = {
+	const e = types::slice {
+		data = self.entries_sec.buf: *[*]u8,
+		length = 128,
+		capacity = 128
+	};
+
+	return *(&e: *const []entry);
+};
+
+fn block_commit(self: *block) void = {
+	sector::commit(&self.header_sec);
+	//sector::commit(&self.entries_sec);
+};
+
+fn block_fetch(self: *block) void = {
+	sector::fetch(&self.header_sec);
+	sector::fetch(&self.entries_sec);
+};
+
+fn block_drop(self: *block) void = {
+	sector::finish(&self.header_sec);
+	sector::finish(&self.entries_sec);
+};
+
+export type header = struct {
+	@offset(0) signature: u64,
+	@offset(8) revision: u32,
+	@offset(12) header_size: u32,
+	@offset(16) header_crc32: u32,
+	@offset(20) reserved0: u32,
+	@offset(24) header_lba: u64,
+	@offset(32) backup_header_lba: u64,
+	@offset(40) first_lba: u64,
+	@offset(48) last_lba: u64,
+	@offset(56) disk_guid: [2]u64,
+	@offset(72) entries_lba: u64,
+	@offset(80) entries_len: u32,
+	@offset(84) entry_size: u32,
+	@offset(88) entries_crc32: u32
+};
+
+export type entry = struct {
+	@offset(0) part_type: [2]u64,
+	@offset(16) part: [2]u64,
+	@offset(32) lba_begin: u64,
+	@offset(40) lba_end: u64,
+	@offset(48) attributes: u64,
+	@offset(56) name: [72]u8
+};
+
+export fn validate(self: *gpt) bool = {
+	if (getheader(self).signature != 0x5452415020494645) {
+		return false;
+	};
+
+	return true;
+};
+
+export fn from(fd: io::file) (*gpt | nogpt | errors::error) = {
+	const prim_header_sector = sector::map(fd, 1, 1);
+	sector::fetch(&prim_header_sector);
+	const prim_header = prim_header_sector.buf: *[*]u8: *header;
+	// XXX validate header
+
+	const prim_table_sector = sector::map(fd, prim_header.entries_lba, prim_header.entries_lba + 128*128/512 - 1);
+	sector::fetch(&prim_table_sector);
+
+	// Create the primary GPT copy
+	const primary = block {
+		header_sec = prim_header_sector,
+		entries_sec = prim_table_sector,
+		header = prim_header,
+		entries = prim_table_sector.buf: *[*]u8: *[128]entry
+	};
+
+
+	const back_header_sector = sector::map(fd, prim_header.backup_header_lba, prim_header.backup_header_lba);
+	sector::fetch(&back_header_sector);
+	const back_header = back_header_sector.buf: *[*]u8: *header;
+	//XXX validate header
+
+	const back_table_sector = sector::map(fd, back_header.entries_lba, back_header.entries_lba + 128*128/512 - 1);
+
+	sector::fetch(&back_table_sector);
+
+	// Create the backup block structure
+	let backup = block {
+		header_sec = back_header_sector,
+		entries_sec = back_table_sector,
+		header = back_header,
+		entries = back_table_sector.buf: *[*]u8: *[128]entry
+	};
+
+
+	const mbr_sec = sector::map(fd, 0, 0);
+
+	// Allocate the GPT structure
+	let self = alloc(gpt {
+		mbr_sec = mbr_sec,
+		mbr = mbr_sec.buf: *[*]u8: *mbr::mbr,
+		primary = primary,
+		backup = backup
+	});
+	
+	// Fetch the MBR
+	sector::fetch(&self.mbr_sec);
+
+	return self;
+};
+
+// Frees the resources associated with the GPT structure.
+export fn finish(self: *gpt) void = {
+	sector::finish(&self.mbr_sec);
+	block_drop(&self.primary);
+	block_drop(&self.backup);
+	free(self);
+};
+
+// Updates the data structures from the disk
+export fn fetch(self: *gpt) void = {
+	sector::fetch(&self.mbr_sec);
+	block_fetch(&self.primary);
+	block_fetch(&self.backup);
+};
+
+export fn mkbackup(self: *gpt) void = {
+	rt::memcpy(self.backup.header, self.primary.header, size(header));
+	rt::memcpy(self.backup.entries, self.primary.entries, size([128]entry));
+	
+	self.backup.header.header_lba = self.backup.header_sec.lba_begin;
+	self.backup.header.backup_header_lba = self.primary.header_sec.lba_begin;
+	self.backup.header.entries_lba = self.backup.entries_sec.lba_begin;
+};
+
+// Commits changed done on the data structure to the disk
+export fn commit(self: *gpt) void = {
+	// XXX: CRC32 checksum
+
+	sector::commit(&self.mbr_sec);
+	block_commit(&self.primary);
+	block_commit(&self.backup);
+	//const header = getheader(self);
+
+	// XXX: update copy
+	//sector::commit_at(self.mbr, self.mbr.fd, header.backup_header_lba);
+};
+
+// Updates the CRC32 checksums of the different blocks
+export fn chksums(self: *gpt) void = {
+	self.primary.header.header_crc32 = header_crc32(self.primary.header);
+	self.backup.header.header_crc32 = header_crc32(self.backup.header);
+};
+
+// Gets the MBR structure. Return value is borrowed from argument.
+export fn getmbr(self: *gpt) *mbr::mbr = {
+	return self.mbr_sec.buf: *[*]u8: *mbr::mbr;
+};
+
+// Gets the GPT primary header structure. Return value is borrowed from argument.
+export fn getheader(self: *gpt) *header = {
+	return block_getheader(&self.primary);
+};
+
+// Gets the GPT primary entries structures. Return value is borrowed from argument.
+export fn getentries(self: *gpt) []entry = {
+	return block_getentries(&self.primary);
+};
diff --git a/main.ha b/main.ha
new file mode 100644
index 0000000..89e6686
--- /dev/null
+++ b/main.ha
@@ -0,0 +1,18 @@
+use fmt;
+use getopt;
+use os;
+
+use convert;
+use mbr;
+use gpt;
+
+export fn main() void = {
+	if (len(os::args) < 2) {
+		fmt::fatalf("{}: expected command", os::args[0]);
+	};
+
+	switch (os::args[1]) {
+	case "convert" => convert::convert(os::args[1..]);
+	case => fmt::fatalf("{}: no such command {}", os::args[0], os::args[1]);
+	};
+};
diff --git a/mbr/mbr.ha b/mbr/mbr.ha
new file mode 100644
index 0000000..ceb115f
--- /dev/null
+++ b/mbr/mbr.ha
@@ -0,0 +1,50 @@
+use io;
+
+use sector;
+use errors;
+
+def mbr_lba: size = 0;
+
+export type nombr = !void;
+
+export type mbr = struct {
+	@offset(0) bootstrap: [440]u8,
+	@offset(440) udid: u32,
+	@offset(444) reserved: u16,
+	@offset(446) entries: [4]mbr_entry,
+	@offset(510) magic: u16,
+};
+
+export type mbr_entry = struct {
+	@offset(0) attributes: u8,
+	@offset(4) part_type: u8,
+	@offset(8) lba_begin: u32,
+	@offset(12) lba_end: u32, 
+};
+
+export fn validate(self: *mbr) bool = {
+	if (self.magic != 0xaa55) {
+		return false;
+	};
+
+	return true;
+};
+
+// Gets a handle to the MBR of a partition.
+// Return value is returned to user. Resource should be freed with mbr::finish.
+export fn from(fd: io::file) (*mbr | nombr | errors::error) = {
+	const self = io::mmap(null, sector::length, io::prot::READ | io::prot::WRITE, io::mflags::SHARED, fd, sector::lba(mbr_lba))!: *mbr;
+	
+	if (!validate(self)) {
+		io::munmap(self, sector::length)?;
+		return nombr;
+	};
+	
+	return self;
+};
+
+// Frees the resources associated with the MBR partition.
+// User revokes ownership.
+export fn finish(self: *mbr) (void | errors::error) = {
+	io::munmap(self, sector::length)?;
+};
diff --git a/sector/sector.ha b/sector/sector.ha
new file mode 100644
index 0000000..50f417b
--- /dev/null
+++ b/sector/sector.ha
@@ -0,0 +1,48 @@
+use io;
+use types;
+
+use fmt;
+
+export const length: u64 = 512;
+
+export fn lba(no: u64) size = {
+	return no * length;
+};
+
+export type sector = struct {
+	buf: []u8,
+	fd: io::file,
+	lba_begin: u64,
+	lba_end: u64,
+};
+
+export fn map(fd: io::file, lba_begin: u64, lba_end: u64) sector = {
+	let self = sector {
+		buf = alloc([0...], (lba_end - lba_begin + 1)*length),
+		fd = fd,
+		lba_begin = lba_begin,
+		lba_end = lba_end
+	};
+
+	return self;
+};
+
+export fn finish(self: *sector) void = {
+	free(self.buf);
+};
+
+export fn fetch(self: *sector) void = {
+	// XXX proper error
+	io::seek(self.fd, (self.lba_begin * length): io::off, io::whence::SET)!;
+	io::read(self.fd, self.buf)!;
+};
+
+export fn commit(self: *sector) void = {
+	io::seek(self.fd, (self.lba_begin * length): io::off, io::whence::SET)!;
+	io::write(self.fd, self.buf)!;
+};
+
+export fn commit_at(self: *sector, fd: io::file, lba: u64) void = {
+	io::seek(fd, (lba * length): io::off, io::whence::SET)!;
+	io::write(fd, self.buf)!;
+};