Original ipmsg protocol specification is
written in Japanese.
This document was translated by
Mr.Kanazawa.
This document is not verified yet.
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IP Messenger communication protocol (Draft-9) 1996/02/21
Modified 2003/01/14
H.Shirouzu
shirouzu@h.email.ne.jp
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About IP Messenger
This
is a Send/Receive message service using the TCP/UDP Port.
Characteristics
IP
Messenger can be installed in any OS if TCP/IP is used on your machine.
Dynamic
member recognition can be done within your network or specified network.
You
can exchange messages between all IPMsg members.
Function description
Use
TCP/UDP port(default:2425). See the following descriptions
(Message
Send/Receive: UDP, File Send/Receive: TCP)
1.
Command
1) Command functions (Low 8 bits from command number 32 bits)
IPMSG_NOOPERATION No Operation
IPMSG_BR_ENTRY Entry to service (Start-up with a
Broadcast command)
IPMSG_BR_EXIT Exit from service (End with a
Broadcast command)
IPMSG_ANSENTRY Notify a new entry
IPMSG_BR_ABSENCE Change absence mode
IPMSG_BR_ISGETLIST Search valid sending host members
IPMSG_OKGETLIST Host list sending notice
IPMSG_GETLIST Host list sending request
IPMSG_ANSLIST Host list sending
IPMSG_SENDMSG Message transmission
IPMSG_RECVMSG Message receiving check
IPMSG_READMSG Message open notice
IPMSG_DELMSG Message discarded notice
IPMSG_ANSREADMSG Message open confirmation notice(added from
version-8)
IPMSG_GETFILEDATA File Transfer request by TCP
IPMSG_RELEASEFILES Discard attachment file
IPMSG_GETDIRFILES Attachment hierarchical file request
IPMSG_GETINFO Get IPMSG version info.
IPMSG_SENDINFO Send IPMSG version info.
IPMSG_GETABSENCEINFO Get absence sentence
IPMSG_SENDABSENCEINFO Send absence sentence
IPMSG_GETPUBKEY RSA Public Key Acquisition
IPMSG_ANSPUBKEY RSA Public Key Response
2) Option flag (High 24 bits from command number 32 bits)
IPMSG_ABSENCEOPT Absence mode(Member recognition command)
IPMSG_SERVEROPT Server(Reserved)
IPMSG_DIALUPOPT Send individual member
recognition command
IPMSG_SENDCHECKOPT Transmission check
IPMSG_SECRETOPT Sealed message
IPMSG_READCHECKOPT Sealed message check(added from ver8)
IPMSG_PASSWORDOPT Lock
IPMSG_BROADCASTOPT Broadcast message
IPMSG_MULTICASTOPT Multi-cast(Multiple casts selection)
IPMSG_NEWMUTIOPT New version multi-cast(reserved)
IPMSG_AUTORETOPT Automatic response(Ping-pong protection)
IPMSG_NOLOGOPT No log files
IPMSG_NOADDLISTOPT Notice to the members outside of BR_ENTRY
IPMSG_FILEATTACHOPT File attachment
IPMSG_ENCRYPTOPT Code
IPMSG_NOPOPUPOPT (No longer valid)
IPMSG_RETRYOPT Re-send flag(Use when acquiring
HOSTLIST)
3) Extended code flag (hex format combination)
IPMSG_RSA_512
IPMSG_RSA_1024
IPMSG_RSA_2048
IPMSG_RC2_40
IPMSG_RC2_128
IPMSG_RC2_256
IPMSG_BLOWFISH_128
IPMSG_BLOWFISH_256
IPMSG_SIGN_MD5
4) Extended files for attachment (fileattr low 8 bits)
IPMSG_FILE_REGULAR
IPMSG_FILE_DIR
IPMSG_FILE_RETPARENT
IPMSG_FILE_SYMLINK
IPMSG_FILE_CDEV
IPMSG_FILE_BDEV
IPMSG_FILE_FIFO
IPMSG_FILE_RESFORK
5) Attachment file extended attribute(fileattr high 24 bits)
IPMSG_FILE_RONLYOPT
IPMSG_FILE_HIDDENOPT
IPMSG_FILE_EXHIDDENOPT
IPMSG_FILE_ARCHIVEOPT
IPMSG_FILE_SYSTEMOPT
6) Extended file attribute for attachment file
IPMSG_FILE_UID
IPMSG_FILE_USERNAME
IPMSG_FILE_GID
IPMSG_FILE_GROUPNAME
IPMSG_FILE_PERM
IPMSG_FILE_MAJORNO
IPMSG_FILE_MINORNO
IPMSG_FILE_CTIME
IPMSG_FILE_MTIME
IPMSG_FILE_ATIME
IPMSG_FILE_CREATETIME
IPMSG_FILE_CREATOR
IPMSG_FILE_FILETYPE
IPMSG_FILE_FINDERINFO
IPMSG_FILE_ACL
IPMSG_FILE_ALIASFNAME
IPMSG_FILE_UNICODEFNAME
2.Command format(Use all character strings)
1) Command(Format version-1)
Ver(1)
: PacketNo : SenderName : SenderHost : CommandNo : AdditionalSection
2) An example for Message Send/Receive by using the current command
format
"1:100:shirouzu:jupiter:32:Hello"
3.Command process overview
1) Member recognition
An
IPMSG_BR_ENTRY command notifies a new entry to the current
members
at start-up.
All
members add the new member to their list after getting a notification message.
An
IPMSG_ANSENTRY command sends a message back to the new member.
The
new member gets the current member data by a
IPMSG_ANSENTRY
command. All members can communicate as long as an
IP
packet exists.
An
IPMSG_BR_ABSENCE command broadcasts absence mode cancel or
nickname
change to all members. However, an IPMSG_ANSENTRY command
does
not send a message back, which is different from an IPMSG_BR_ENTRY
command.
IPMSG_BR_ENTRY,
IPMSG_ANSENTRY, and IPMSG_BR_ABSENCE commands
use
an IPMSG_ABSENCEOPT flag for absence mode. Input a nickname to
additional
command.
Add
an IPMSG_DIALUPOPT flag for dial-up users who can't be reached by
a
broadcast command. A member recognition
command needs to be
sent
individually to the members with this optional flag.
(Extended
group)IPMSG_BR_ENTRY and IPMSG_BR_ABSENCE commands
sends
a group name by adding the new group name after the current
command
format character strings (Input '\0' between the current
command
and extended name).
2) Send/Receive Message
Send
Message uses an IPMSG_SENDMSG command that can input a message
in
the extended area.
Receive
Message sends back an IPMSG_RECVMSG command only
if
an IPMSG_SENDCHECKOPT flag is ON. Input the original packet number
to
the extended area.
Broadcast
Message Send uses an IPMSG_BOADCASTOPT command
and
an IPMSG_SENDMSG flag should be ON.
Auto-Send
packet(absence notice) needs to be added to IPMSG_AUTORETOPT
for
ping-pong protection. If either one or another packet is ON, then
confirmation/auto-send
packet is not sent back.
Send
Message Sealing needs to be an IPMSG_SECRETOPT packet ON.
In
this case, Receive Message sends an IPMSG_READMSG command.
Input
the original packet number to the extended area.
(Additional
IPMSG_NOADDLISTOPT)
When
receiving an IPMSG_SENDMSG packet from a host that is
not
on your Send/Receive list, IPMsg will either confirm a host by
sending
an IPMSG_BR_ENTRY command or add a host name to
the
Send/Receive list.
However,
single-shot Message Send/Receive action needs to be avoided.
Add
an IPMSG_NOADDLISTOPT flag to an IPMSG_SENDMSG command.
(Additional
IPMSG_READCHECKOPT from version-8)
When
an IPMSG_READMSG command contains an IPMSG_READCHECKOPT flag,
IPMsg
process is the same as IPMSG_SENDMSG with an
IPMSG_SENDCHECKOPT
flag.
However,
Send Message uses an IPMSG_ANSREADMSG command,
not
IPMSG_RECVMSG.
3) Message Send/Receive 亅encrypted extension (Added in the version-9)
Use
the combination of Public-key(RSA) and common key(RC2/Blowfish).
(Encrypted
extension area is used in hex format.)
(Public
key acquisition)Send an IPMSG_GETPUBKEY command to Receive
Message.
Receive Message gets an IPMSG_ANSPUBKEY that
means
receiving RSA public key from Send Message.
IPMSG_GETPUBKEY/IPMSG_ANSPUBKEY
both require the value which is
encryption
capability (Exp. IPMSG_RSA_1024) flag uses "OR" at first
part
of extension
In
addition, In IPMSG_ANSPUBKEY, public key written as EE-NNNNNN
E=Exponent丄N=method)devide
by ':'. and Input the Fdelimiter '-'
between
E and N.
This
sequence can be skipped after the 2nd Send/Receive process by
memorizing
public key and encrypted data.
(Encrypted
message)After a sender creates a common key that is
supported
both sender and receiver, a common key can encrypt a message.
In
addition, a receiver's public key encrypts the common key.
(Encrypted
message transmission) IPMSG_ENCRYPTOPT is used in
IPMSG_SENDMSG.
At the first part of extension, input the value which
is
'or' resoult from Convination of public key and common key type .
Then
use common key which encrypt with public key devide by ':'.
Then
input message which is eccrypted by public key devide by ':'.
If
both supports IPMSG_SIGN_XXX, then add ':' and signeture.
Also,
In the method of encode padding, PKCS#1ECB key is used for RSA,
PKCS#5
CBC common key is used for RC2/blowfish.
Also,
The Packet related to Entry manifestation the capability of
ecryption
support using IPMSG_ENCRYPTOPT
4) Extension with file attachment(Available from version-9)
An
IPMSG_SENDMSG command with an IPMSG_FILEATTACHOPT flag for
File
transfer (download permission)notification sends a message
with
attachment.
Input
'\0' after the message and attachment file data.
fileID:filename:size:mtime:fileattr[:extend-attr=val1
[,val2...][:extend-attr2=...]]:\a:fileID...
(size,
mtime, and fileattr describe hex format.
If a filename contains ':', please replace
with "::".)
When
Receive Message downloads an attachment file, an IPMSG_GETFILEDATA
command
requests a data transmission packet to the TCP port that is the same
number
as
the UDP sending port number. Input packetID:fileID:offset to the extended area.
(Use
all hex format.)
File
Transfer side receives the request. After recognizing that it's a correct
request,
then
send the specified data (no format)
When
the data receiving side downloads a hierarchical attachment file,
use
an IPMSG_GETDIRFILES command and input a packetID:fileID
to
the extended area and send a data transmission request packet.
(all
hex format)
Data
sending side sends the following hierarchical data format.
header-size:filename:file-size:fileattr[:extend-attr=val1
[,val2...][:extend-attr2=...]]:contents-data
Next
headersize: Next filename...
(All
hex format except for filename and contetns-data)
header-size
is from the beginning of header-size to the delimiter ':'
that
is before contents-data. extend-attr can be omitted and used multiple
extended
attributes. Use '=' for data input.
When
fileattr is IPMSG_FILE_DIR, IPMsg recognizes that it is automatically
in
the directory, the next file data is after the directory.
When
fileattr is IPMSG_FILE_RETPARENT, IMPsg recognizes that it returns
to
the parent directory. In this case, File name is always "." and the
attribute
value
is the current directory data.
Sending
process starts from the attachment directly and returns the
IPMSG_FILE_RETPARENT
command to the attachment directory.
Add
an IPMSG_FILEATTACHOPT flag for an Entry packet to support the
attachment
file.
5) Other commands
When
acquiring different versions, send an IPMSG_GETINFO command.
Receiving
side sends the version information character string to
extended
area.
Send
an IPMSG_GETABSENCEINFO command for acquiring an absence message.
Receiving
side sends an IPMSG_SENDABSENCEINFO back if the status is absence mode.
If
the status is not absence mode, a character string "Not absence mode"
will be sent back.
6) Confirmation/Retry
If
a confirmation packet for IPMSG_SENDMSG or IPMSG_RECVMSG is not delivered
within
a specified time, then it will be sent again.
A
number of retry actions or interval period is depended on the current
condition.
4.
Other
1) Linefeed
Linefeed
characters in Send Message is standardized with UNIX type ('0x0a').
Please
change if needed.
2) Delimiter ':'
':'
is used as a delimiter. You can't use this delimiter for user name
and
host name.
If
the use/host names contain a ':', please replace with another sign,
for
an example ';'.
Although
using this delimiter isn't problem as yet, I may create an
escape
sequence.
3) Kanji codes
SJIS
5.
Contact e-mail address
E-Mail
shirouzu@h.email.ne.jp
Note
See
ipmsg.h for command codes.
Please
e-mail me your comments and suggestions.
Ipmsg里面UDP使用的數據包是下面msgMng的結構組成
msgMng數據包格式：
1 程序版本號
2數據包序列號
3用戶名
4主機名5
5命令
6消息內容
7 額外數據
1到5的內容是以“：”為分隔符，消息和額外數據以數據“0“分隔
發(fā)送文件的整個邏輯過程:
1發(fā)送端發(fā)送一個UDP數據包，通知接收端準備接收文件,通知在一個socket上監(jiān)聽TCP連接事件
2 接收端回發(fā)一個UDP數據包,告訴發(fā)送端已準備好接收數據,并請求一個TCP的連接
3發(fā)送端接收連接的請求,并將文件映射到內存中,然后創(chuàng)建發(fā)送文件線程,開始進行數據的發(fā)送
4接收端創(chuàng)建接收的文件,然后創(chuàng)建接收數據的線程,開始收取數據.接受完以后,將數據寫入到創(chuàng)建好的文件中.