Subversion Repositories planix.SVN

protocol version id

both client and server send '\n' terminated ascii of the form

venti-<versions>-<software>

<software> = is a software id which is ignored but may be useful for debugging

If the server and client have the same version number then this

version is used.  Otherwise backup to the greatest common

major version number, e.g. 1.00 2.00 etc.  If no version in

common then abort.  The idea is both client and server should

support a continusous range of major versions.  The minor version

numbers are used for development purposes.

After protocol negotiation switch to binary format

all numbers sent big endian

strings are sent with 2 byte length without nulls and in utf-8 max size of 1K

RPC protocol

header 

	op[1]	byte op

	tid[2]	transation id

client manages the tid space.  Until session is established tid must equal 0.

i.e. only one outstanding op.

CipherStrength

	None,

	Auth,

	Weak,

	Strong

CipherAlgorithms

	None

	SSL3

	TLS1

CompressionAlgorithms

	None

	Deflate

	Thwack?

BlockTypes

	Root

	Pointer

	Data

==============================================

TPing

RPing

RError

	error: string

THello

	version:string;		know to be supported by both

	uid: string

	uhash[20]		use for cipher boot strapping

	cipherstrength[1]

	ncipher[1];

	cipher[ncipher];

	ncompressor[1];

	compressor[ncompressor];

RHello

	sid: string

	shash[20];		use for cipher bott strapping

	cipher[1];

	compressor[1];

use srp style authentication

	g=2

	N is safe prime 1024 bits - find a good prime!

	x = H("venti" H(sid) H(uid) H(password))

	v = g^x

	a = random

	b = random

	B = (v + g^b)

	A = g^a

	u = first four bytes of H(B)

	S = (B - g^x) ^ (a + u*x) = (A * v^u) ^ b

	K = H(S)

	M1 = H(H(versions) H(THello) H(RHello) A B K)

	M2 = H(A M1 K)

TAuth0

	A[128]

RAuth0

	B[128]

TAuth1

	M1[20]

RAuth1

	M2[20]

push cipher

push compression

TWrite

	length[2] max 56*1024

	type[1]

	data[length]

RWrite

	hash[20]

TRead

	hash[20]

	type[1]

	length[2]

RRead

	length[2]

	data[length]

============================================================

simplified access when trusting the server

reduces network bandwidth since pointer blocks are not

sent to the client - can also enable permission checking

RReadRoot

	root[20]

TReadRoot

	name: string

	type: string

	blocksize[2]

	nblock[8]

	time[4]

	uid: string;

	gid: string

RReadData

	root[20]

	block[8]

	length[2]

TReadData

	length[2]

	collision[1]

	data[length]

==============================================

maybe some clients should be required to navigate to block via root nodes.

This would enable permission checking via access to the root node.

RTagOpen

	tag[2]

	root[20]

TTagOpen

QTagRead

	tag[2]

	type[1]

	length[2]

RTagRead

	length[2]

	data[length]

QTagWalkRead

	tag[2]

	ntag[2]		can reuse a tag to do an implict clunk

	index[2]

	type[1]

	length[2]

RTagWalkRead

	length[2]

	data[length]

RTagClunk

	tag[2]

TTagClunk

============================

Types of blocks

Data

Root

	name[128]

	type[128]

	score[20]	- DirBlock

Pointer

	score[20]*	the number of hashes can be less than fanout when the

			tree is not full

DirBlock

	DirEntry[32]*

DirEntry	

	pointersize[2]	- pointer block size

	datasize[2]	- data blocks size

	flag[1]		directory

	size[7]		in bytes - determines pointer depth - intermidate truncated block count as full

	score[20]	root of pointer blocks or data block 

============================

mode flags

	(1<<0)	ModeOtherExec

	(1<<1)	ModeOtherWrite

	(1<<2)	ModeOtherRead

	(1<<3)	ModeGroupExec

	(1<<4)	ModeGroupWrite

	(1<<5)	ModeGroupRead

	(1<<6)	ModeOwnerExec

	(1<<7)	ModeOwnerWrite

	(1<<8)	ModeOwnerRead

	(1<<9)	ModeSticky

	(1<<10)	ModeSetUid

	(1<<11)	ModeSetGid

	(1<<12)	ModeAppend

	(1<<13)	ModeExclusive

	(1<<14)	ModeLink

	(1<<15)	ModeDir	- duplicates dir entry

	(1<<16) ModeHidden

	(1<<17) ModeSystem

	(1<<18) ModeArchive

	(1<<19) ModeTemporary

	(1<<18) ModeCompressed

	(1<<19) ModeEncrypted

extraType

	2	Plan9

	version[4]

	muid: string

	3 NT Time

	createTime[8];

	modifyTime[8];

	accessTime[8]

MetaEntry

	name: string	/* must be first */

	direntry[4]

	id[8]

	uid: string

	gui: string

	mtime[4]

	ctime[4]

	atime[4]

	mode[4] 

	extratype;

	extrasize[2]

	extra:[nextra]

MetaEntry Block

	magic[4]

	size[2]

	free[2]	- used to determine if work compacting

	maxindex[2] - size of index table in bytes

	nindex[2]

	index[2*nindex]

per OS directory entries?

inode...