Virtual1's Hotline Server Protocol Guide
•• Virtual1's Hotline Server Protocol Guide ••[edit | edit source]
Version 1.50b Last Update: 02/12/99
Download current versions off the VirtualFTP Hotline server, at virtualftp.neotek.net
This guide was generated during several days of intense use of OTsessionWatcher, to get the protocol figured out in preparation for the development of HotSocket, a RealBasic socket-based class for use as a Hotline Client/Server interface.
Significant changes in 1.5:
- transaction 354 (userlist) is sent by server on login, the client does not need to request a userlist.
Thanks goes out to XAW and his development of the BHC, (Basic Hotline Client) whose RealBasic sourcecode gave me the insight necessary to begin to understand what I was seeing in the sessionwatcher. Thanks also to the creators of mBot, without whose greed and lack of interest in releasing sourcecode led me to make HotSocket, and thus, the need to make this guide. ;)
CHANGES HAVE BEEN MADE TO THE "PATH" TYPE. Please check the lengths of the bytes before the path strings, as they are handled differently than expected, and will not work the "old way" with 1.5's threaded news!
Chapter 1: NUMBERS AND STRINGS[edit | edit source]
long = 4 bytes short = 2 bytes
Anywhere there is a number that is preceeded by a length, (such as if the number is the only part of an object, like Socket or Icon) then the number can be a short OR a long. HL software will always pick the smaller of the two when sending, though it does not hurt them to receive a long that is zero.
Numbers appear to be stored as "two's complement".
0 = 00 00 00 00 (you can send as a short 00 00)
+1 = 00 00 00 01 (you can send as a short 00 01)
+65535 = 00 00 FF FF (you can send as a short FF FF)
+65536 = 00 01 00 00
+2 = 7F FF FF FF
-2147483648 = 80 00 00 00 (now counting backwards toward zero)
-1 = FF FF FF FF
This is how 2's complement works. The ctrl-F12 does not seem to parse this entirely correctly, but I am assuming this is how things are supposed to work internally in Hotline. The only place you'd have to worry about this is if you ran into a file > 2.1gb that was returning a negative filesize or something. Remember that icons can be negative numbers. (though the numbers are not likely to get near the "crossover" point at 231)
It might be simpler to just send everything you can as a long. Some items must be sent as shorts if they don't have a length indicated in the protocol, such as all length indicators and some items in filelist/userlist entries. Anywhere you see short() or long(), it means that you MUST send it that way, because there is no length indicator. Anywhere you see number(), you need to send the length as a short, followed by the number, in your chosen format. There are a few oddball exceptions. Icon numbers are numbers, and normally the server will send them in Number format. (length followed by the number) Userlists however, send the Socket, Icon, and Status objects without length bytes, (all as shorts) Filelists have the same limitation. In the event of a negative icon number, (it can happen, and does work) the icon will be sent as a SHORT two's complement number. They are very easy to convert fortunately... just lop off the the first two characters of the number. -3 changes from FF FF FF FD to FF FD. This limits your numeric range to -32768 <-> +32767.
Strings are sent as a length (always a short) followed by the string's characters. Strings marked as "encoded" have each character of the string EOR'd with $FF. i.e. y=chr(255-asc(x)) It's not meant to be hard to crack, just hard to READ and easy to DO. Note that strings added to the protocol in HL1.5 are sent as "pascal" strings, and have a length specified by ONE BYTE, not two. (no consistency!) These are referred to as "pstring" instead of "string" for clarity below.
Chapter 2: OBJECTS[edit | edit source]
objects are sent under the following format:
• object header
• short (object ID number)
• short (object length) does not count these four header bytes
• object data
if it's a number >=0 and <65536:
• short (number)
if it's a number >65535:
• long (number)
if it's a number <0:
• long (232+number)
if it is a string:
• string encoded strings have all chars EOF $FF)
if it is a filelistentry
• file type four characters, or "fldr" if folder, or
"alis" if unresolved alias
• file creator four characters, or long(0) if folder
• long (file size in bytes, zero if folder)
• long (contained items, zero if app/doc)
• long (filename length)
• string (filename)
if it is a Path
• short (directory levels)
• one or more directory levels
• short (0) not sure what it's for
• byte (length of dir name)
• string (dir name)
if it is a userlistentry
• short (socket)
• short (icon)
• short (status)
• short (length of nick)
• string (nick)
if it is a datetime
• short (base year - usually 1904)
• short (0)
• long (number of seconds this date is from midnight, jan 1, base year)
if it is a resumeinfo
• "RFLT" - Resume FiLe Transfer
• short (1)
• 34 zeros = 8 x long(0) + 1 x short(0)
• short (2)
• Data descriptor
• "DATA"
• long (index to start at)
• long (0)
• long (0)
• Resource descriptor
• "MACR"
• long (index to start at)
• long (0)
• long (0)
if it is a newsgroup
• const ($33 31 31 33 - no idea why, but it's always there)
• long (post count)
• pstring (category name)
• const ($00)
• posts
• long (thread ID)
• long (date)
• long (parent thread ID)
• const ($00 00 00 00)
• short (message element count)
• pstring (subject)
• pstring (poster)
• message elements
• pstring (mime type)
• short (post size?)
if it's a newsfolderitem
• byte (item type: $01=folder, $0A=category)
• raw data (folder/category name, no length byte)
Integer objects are preceeded by a length for a reason. Do not assume that
just because the object you are expecting can only be a number 0-50 ,that
it will have to be sent as a short. It could be sent as a long, and we don't
want to break the socket for such a simple misunderstanding. The reverse is
true for longs, they may be sending an icon number that is 5, and decide to
save a few bytes and send it as a short. BEWARE.
client objects and their ID numbers:
ID# Name Object Type 100 errormsg string 101 message string 102 nick string 103 socket number 104 icon number 105 login encoded string NOT encoded in transaction #352 106 password encoded string 107 xferID number the ID number of the file transfer (usually 32 bit) 108 xfersize number size of file xfer, in bytes (smaller for resumes!!) 109 parameter number specifies icon for broadcast, also emote flag 110 privs eight bytes can make 64 flags, only use 27 111 ??? 112 status number 0=black non-idle 113 ban short (1) include to make a kick into a ban 114 chatwindow four random bytes?? example: 84 47 5E 02 115 subject string the new subject of a chat window 116 waiting count object 200 fileentry filelistentry 201 filename string 202 path path 203 resumeinfo resume 204 resumeflag short (1) 205 infolongtype string "Text File" 206 infocreator string "Simpletext" 207 infosize number 208 infocreated datetime 209 infomodified datetime 210 comment string 211 newfilename string 212 targetpath path 213 infotype string the 4-char macos type code (redundant, client already has C/T) 214 Quote string 300 userlistentry userlistentry 320 newsfolderitem newsfolderitem 321 catlist newsgroup 322 category string 325 newspath path this one revealed to me its "true nature" in v1.5 ! 326 threadID number the serial number of a message, for threading 327 newstype string 328 newssubject string 329 author string 330 newsdate date 331 prevthread number 332 nextthread number 333 newsdata string 334 unknown! number?
Note! XferSize is the actual number of bytes in the file if it's a download, but it's the size of the file datablock (length of file - 146 - length of filename - length of comment) if it's an upload! :P (that's length PLUS 146 PLUS filename)
Chapter 3: TRANSACTIONS[edit | edit source]
Transaction are sent under the following format:
• header • short (transaction class) 0=info/request, 1=reply • short (transaction ID number) server replies are always zero • long (task number) • long (error code) valid if this is a reply, 0=ok, 1=err • long (length of data block) • long (length of data block) yes, again. I don't know why. • data • short (number of objects in transaction) • objects can be one, many, or none
It would be wise to assume that objects can be passed in IN ANY ORDER. The other Hotline Client sockets I have seen thus far will crumble to dust if Hinks changes the order of the objects, and I just bet his clients and servers are designed to handle this. BEWARE.
Transaction IDs, classes, types, names, and objects:
ID# Cls Init Type Name Object(s)
101 0 Client request GetNews (no objects passed)
0 1 Server reply GetNews message
102 0 Server info NewPost message
103 0 Client request PostNews message
104 0 Server info Broadcast message
104 0 Server info Error parameter,message
104 0 Server info PrivateMessage socket,nick,message(,banflag)
105 0 Client info SendChat message(,chatwindow)(,parameter)
106 0 Server info RelayChat message(,chatwindow)
107 0 Client request Login login,password,nick,icon
108 0 Client request SendPM socket,message(,banflag)(,quote)
109 0 Server info Agreement message
110 0 Client request Kick socket(,ban)
111 0 Server info Disconnected message
112 0 Client request CreatePchatWith socket
0 1 Server reply CreatePchatWith chatwindow,socket,icon,status,nick
113 0 Server info InvitedToPchat chatwindow,socket,nick
113 0 Client info AddToPchat socket,chatwindow
114 0 Client Info RejectPchat chatwindow
115 0 Client request RequestJoinPchat chatwindow
0 1 Server reply JoiningPchat userlistentry(,userlistentry,...)(,subject)
116 0 Client Info LeavingPchat chatwindow
117 0 Server Info JoinedPchat chatwindow,socket,icon,status,nick
118 0 Server Info LeftPchat chatwindow,socket
119 0 Server Info ChangedSubject chatwindow,subject
120 0 Client Request RequestChangeSubject chatwindow,subject
200 0 Client request FolderList (path)
0 1 Server reply FolderList {fileentry}
201 (unused)
202 0 Client request Download filename(,path)(,resumeinfo)
0 1 Server reply Download xfersize,xferID
203 0 Client request Upload filename,xfersize(,path),(resumeflag)
0 1 Server reply Upload xferid(,resumeinfo)
204 0 Client request MoveToTrash filename(,path)
205 0 Client request CreateFolder filename(,path)
206 0 Client request GetFileInfo filename(,path)
0 1 Server reply GetFileInfo infotype,infolongtype,infocreator,filename,
infocreated,infomodified,infosize(,comment)
207 0 Client request SetFileInfo filename(,path),(newfilename OR comment)
208 0 Client request MoveFile filename(,path)(,targetpath)
209 0 Client request MakeAlias filename(,path)(,targetpath)
300 0 Client request GetUserList (no objects passed)
0 0 Server reply GetUserList {userlistentry}
301 0 Server info UserChange socket,icon,nick(,status)
302 0 Server info UserLeave socket
303 0 Client request GetUserInfo socket
0 1 Server reply GetUserInfo message(,nick)
304 0 Client info ChangeNickIcon icon,nick
350 0 Client request CreateUser login,password,nick,privs
351 0 Client request DeleteUser login
352 0 Client request OpenUser login (NOT ENCODED)
0 1 Server reply OpenUser login,password,privs(,nick)
353 0 Client request ModifyUser nick,login,password,privs
354 0 Server info Userlist {userlistentry}
355 broadcast
370 0 Client request NewsDirlist (newsdir)
1 Server reply NewsDirList {newsfolderitem}
371 0 Client request NewsCatList (newsdir)
1 Server reply NewsCatList (newsgroup)
380 0 Client request DeleteNewsDirCat newspath (kills categories and dirs)
381 0 Client request MakeNewsDir newspath,filename
382 0 Client request MakeCategory newspath,category
400 0 Client request GetThread newspath,threadid,newstype
1 Server reply GetThread newsdata,prevthread,nextthread,newssubject,
author,newstype,newsdate
410 0 Client request PostThread newspath,threadid,newssubject,unknown 334,newstype,newsdata,
1 Server reply PostThread newspath,threadid,newssubject,unknown 334,newstype,newsdata,
411 0 Client request DeleteThread newspath,threadid
Transactions dealing with files always include the filename. If the path is not included, root folder can be assumed. If the file is being moved or aliased, targetpath may also be included. If not, root is assumed as the target.
Transaction #105 (SendChat) is chat. When sent with a parameter of 1, it becomes an emote. Server reply to #352 always returns string(ctrl-G) as password. #353 must send a password string (chr(0)) if password was not changed. Returning string(ctrl-G) will result in that being the user's new password!
Unless otherwise specified, a successful task reply will have an error code of 0 and no objects. Unsuccessful tasks will reply with an error code of 1 and the errormsg object.
Server transaction #104 "Error" is used for when client sends a non-request that fails, such as trying to send public chat when they don't have chat privs. (probably a screw-up by Hinks, he should have made ALL transactions generate a reply, IMHO)
Note: reply to #303 (get info) will be missing the Nick object if you're getting info on a "ghost". (HotSocket will return "" - the HL client returns "Unnamed User") The HL client will not allow a user to set their name to blank. (spaces are OK tho)
Note: a Task is a reply to a request. The object(s) included in the Task
are dependent on what the request was. The Task can be matched back to
its request by using the task number portion of the header. It's probably
possible to reuse task numbers, but don't re-issue a task number in a
request until the current instance of that task number has been replied to!
I have noticed that while the client can create tasks, the server cannot.
This makes sense, because a server would eventually crash or eat up all
available memory if it had to remember tasks until complete, assuming it
was up a week or so and had clients dropping. (leaving tasks in the air)
Chapter 4: LOGGING IN[edit | edit source]
Before sending a login, you must establish a "pipe". Do this by connecting to the port and then exchanging this "handshake" with the server:
CLIENT HELLO • "TRTPHOTL" identifies this is a hotline client • short (1) minimum server version this client is compatible with? • short (2) client version? TRTPHOTL (0) (1) (0) (2) SERVER HELLO •"TRTP" • long (errorcode) - 0=OK you are connected, 1=rejected TRTP (0) (0) (0) (0)
Once these have been exchanged, you can assume you are connected to a HL server and can proceed to login. Until you have received a success reply to your login transaction, the only other transaction you can submit is a request for disconnect. (I think all others are just ignored?)
Once logged in, you are by no means required to request a userlist, request news, or do anything else for that matter. Hinks' client will send the login and then immediately fire off a request for the agreement, userlist and news, before even receiving confirmation of a successful login. (how rude!)
Chapter 5: NOTES[edit | edit source]
I have seen many admins and co-admins running around kicking idle users, saying they are "taking up bandwidth". I was wondering if this was true, and did some pondering. A user that is completely idle (no file xfers) by themselves will take zero bandwidth. There WILL be some bandwidth needed though for each time a user in the userlist goes idle, goes active, changes nick or icon, leaves, arrives, or someone posts public chat. Each of these events requires a task to be sent to every user online, though the amount of data sent is quite small. (typically only 40 bytes or so) News posts also go to all users , (even w/o news privs!) and those can be relatively large in comparison to the other transactions. It sounds kind of silly, but it is in everyone's best interest that on busy file-serving server, you should be quiet and use chat only sparingly.
THE END I hope this is useful for you! :-) - Virtual1