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# 2002-9P2000.9p - Definitions of 9P2000 messages
#
# Copyright (C) 2024 Luke T. Shumaker <lukeshu@lukeshu.com>
# SPDX-Licence-Identifier: AGPL-3.0-or-later
# "9P2000" base protocol
# https://ericvh.github.io/9p-rfc/rfc9p2000.html
# https://github.com/ericvh/9p-rfc/blob/master/9p2000.xml
#
# But due to incompleteness of the draft RFC, the Plan 9 manual
# section-5 and the Plan 9 headers (particularly fcall.h) are often
# better references.
#
# https://github.com/plan9foundation/plan9/tree/main/sys/man/5
# https://man.cat-v.org/plan_9/5/
# https://github.com/plan9foundation/plan9/blob/main/sys/include/fcall.h
version "9P2000"
# tag - identify a request/response pair
num tag = 2
# file identifier - like a UNIX file-descriptor
num fid = 4
# data - u32le `n`, then `n` bytes of data
struct d = "len[4] len*(dat[1])"
# string - u16le `n`, then `n` bytes of UTF-8, without any nul-bytes
struct s = "len[2] len*(utf8[1])"
# "d"? mode - file permissions and attributes
bitfield dm = 4
"31=DIR"
"30=APPEND"
"29=EXCL"
# DMMOUNT has been around in Plan 9 forever, but is
# undocumented, and is explicitly excluded from the 9P2000
# draft RFC. As I understand it, DMMOUNT indicates that the
# file is mounted by the kernel as a 9P transport; that the
# kernel has a lock on doing I/O on it, so userspace can't do
# I/O on it.
"28=_PLAN9_MOUNT"
"27=AUTH"
"26=TMP"
#...
"8=OWNER_R"
"7=OWNER_W"
"6=OWNER_X"
"5=GROUP_R"
"4=GROUP_W"
"3=GROUP_X"
"2=OTHER_R"
"1=OTHER_W"
"0=OTHER_X"
"PERM_MASK=0777" # {OWNER,GROUP,OTHER}_{R,W,X}
# QID Type - see `struct qid` below
bitfield qt = 1
"7=DIR"
"6=APPEND"
"5=EXCL"
"4=_PLAN9_MOUNT" # see "MOUNT" in "dm" above
"3=AUTH"
# Fun historical fact: QTTMP was a relatively late addition to
# Plan 9, in 2003-12.
"2=TMP"
#"1=unused"
# "The name QTFILE, defined to be zero, identifies the value
# of the type for a plain file."
"FILE=0"
# uni"Q"ue "ID"entification - "two files on the same server hierarchy
# are the same if and only if their qids are the same"
#
# - "path" is a unique uint64_t that does most of the work in the
# above statement about files being the same if their QIDs are the
# same; " If a file is deleted and recreated with the same name in
# the same directory, the old and new path components of the qids
# should be different"
#
# - "vers" "is a version number for a file; typically, it is
# incremented every time the file is modified.
#
# - "type" indicates "whether the file is a directory, append-only
# file, etc."; is an instance of the qt bitfield.
struct qid = "type[qt] vers[4] path[8]"
# stat - file status
struct stat = "stat_size[2,val=end-&kern_type]"
"kern_type[2]"
"kern_dev[4]"
"file_qid[qid]"
"file_mode[dm]"
"file_atime[4]"
"file_mtime[4]"
"file_size[8]"
"file_name[s]"
"file_owner_uid[s]"
"file_owner_gid[s]"
"file_last_modified_uid[s]"
# "O"pen flags (flags to pass to Topen and Tcreate)
bitfield o = 1
"0=mode_0" # low bit of the 2-bit READ/WRITE/RDWR/EXEC enum
"1=mode_1" # high bit of the 2-bit READ/WRITE/RDWR/EXEC enum"
#"2=unused"
#"3=unused"
"4=TRUNC"
#"5=unused"
"6=RCLOSE" # remove-on-close
#"7=unused"
"READ = 0" # make available for this FID: Tread()
"WRITE = 1" # make available for this FID: Twrite()
"RDWR = 2" # make available for this FID: Tread() and Twrite()
"EXEC = 3" # make available for this FID: Tread()
"MODE_MASK = 0b00000011"
"FLAG_MASK = 0b11111100"
msg Tversion = "size[4,val=end-&size] typ[1,val=100] tag[tag] max_msg_size[4] version[s]"
msg Rversion = "size[4,val=end-&size] typ[1,val=101] tag[tag] max_msg_size[4] version[s]"
msg Tauth = "size[4,val=end-&size] typ[1,val=102] tag[tag] afid[fid] uname[s] aname[s]"
msg Rauth = "size[4,val=end-&size] typ[1,val=103] tag[tag] aqid[qid]"
msg Tattach = "size[4,val=end-&size] typ[1,val=104] tag[tag] fid[fid] afid[fid] uname[s] aname[s]"
msg Rattach = "size[4,val=end-&size] typ[1,val=105] tag[tag] qid[qid]"
#msg Terror = "size[4,val=end-&size] typ[1,val=106] tag[tag] illegal"
msg Rerror = "size[4,val=end-&size] typ[1,val=107] tag[tag] ename[s]"
msg Tflush = "size[4,val=end-&size] typ[1,val=108] tag[tag] oldtag[2]"
msg Rflush = "size[4,val=end-&size] typ[1,val=109] tag[tag]"
msg Twalk = "size[4,val=end-&size] typ[1,val=110] tag[tag] fid[fid] newfid[fid] nwname[2,max=16] nwname*(wname[s])"
msg Rwalk = "size[4,val=end-&size] typ[1,val=111] tag[tag] nwqid[2,max=16] nwqid*(wqid[qid])"
msg Topen = "size[4,val=end-&size] typ[1,val=112] tag[tag] fid[fid] mode[o]"
msg Ropen = "size[4,val=end-&size] typ[1,val=113] tag[tag] qid[qid] iounit[4]"
msg Tcreate = "size[4,val=end-&size] typ[1,val=114] tag[tag] fid[fid] name[s] perm[dm] mode[o]"
msg Rcreate = "size[4,val=end-&size] typ[1,val=115] tag[tag] qid[qid] iounit[4]"
msg Tread = "size[4,val=end-&size] typ[1,val=116] tag[tag] fid[fid] offset[8] count[4]"
msg Rread = "size[4,val=end-&size] typ[1,val=117] tag[tag] data[d]" # for directories, `data` is the sequence "cnt*(entries[stat])"
msg Twrite = "size[4,val=end-&size] typ[1,val=118] tag[tag] fid[fid] offset[8] data[d]"
msg Rwrite = "size[4,val=end-&size] typ[1,val=119] tag[tag] count[4]"
msg Tclunk = "size[4,val=end-&size] typ[1,val=120] tag[tag] fid[fid]"
msg Rclunk = "size[4,val=end-&size] typ[1,val=121] tag[tag]"
msg Tremove = "size[4,val=end-&size] typ[1,val=122] tag[tag] fid[fid]"
msg Rremove = "size[4,val=end-&size] typ[1,val=123] tag[tag]"
msg Tstat = "size[4,val=end-&size] typ[1,val=124] tag[tag] fid[fid]"
msg Rstat = "size[4,val=end-&size] typ[1,val=125] tag[tag] nstat[2,val=end-&stat] stat[stat]" # See the "BUG" note in the RFC for the nstat field
msg Twstat = "size[4,val=end-&size] typ[1,val=126] tag[tag] fid[fid] nstat[2,val=end-&stat] stat[stat]" # See the "BUG" note in the RFC for the nstat field
msg Rwstat = "size[4,val=end-&size] typ[1,val=127] tag[tag]"
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