3.7 KiB
Introduction
CVR is a command introduced with MSNP2.
It is a Notification Server and as of MSNP8 a Dispatch Server command, without either a request or response payload.
Sends the current client information and retrieves the latest avaliable version of the client. Related to CVQ.
Client/Request
CVR TrID locale system-type system-ver system-arch requesting-library client-version client-identification {user-handle}
Where locale is a 16-bit hexadecimally encoded LCID. 0x0409 is the LCID for English, United States.
Where system-type is a string that defines the operating system you are using, such as winnt.
Where system-ver is the major and minor version of the operating system, such as 5.1.
Where system-arch is the architecture of the processor that is used to run the client, usually i386.
Where requesting-library is the name of the library that requested this CVR, usually MSMSGS or MSNMSGR.
Where client-version is the current client's major, minor and patch version, should be in the format of "{M}M.m.pppp".
Where client-identification is the internal name of the codebase used to create requesting-library, usually MSMSGS.
Where user-handle is the user's handle. Included since MSNP8.
Server/Response
CVR TrID recommended-version recommended-version-2 minimum-allowed-version download-url fallback-url
Where recommended-version is the current version of the client for this system.
Where recommended-version-2 is (usually) the same as recommended-version,
Could possibly be a maximum allowed version? (forced downgrade)
Where minimum-allowed-version is the lowest version the server considers "safe" to connect with.
If the client's client-version is lower than the server's minimum-allowed-version,
the client should automatically disconnect from the server,
and request an forced upgrade using the binary provided in download-url.
Where download-url is the file to download and open to update this client to recommended-version.
Where fallback-url is the URL the client opens if it failed to download download-url for any reason.
Examples
*NOTE: This has been line-breaked.
Lines beginning with .. are continuations of the previous line."
Post-login
C: CVR 1 0x0409 win 4.10 i386 MSMSGS 1.0.0863 MSMSGS
S: CVR 1 5.0.0537 5.0.0537 1.0.0863
.. http://download.microsoft.com/download/msnmessenger/install/5.0/w98nt42kmexp/en-us/setupdl.exe
.. http://messenger.microsoft.com
Client asks if user would like to update, and stays connected.
Pre-login
Since MSNP8.
C: CVR 2 0x0409 winnt 5.1 i386 MSNMSGR 6.0.0602 MSMSGS example@hotmail.com
S: CVR 2 7.0.0813 7.0.0813 6.2.0205
.. http://msgr.dlservice.microsoft.com/download/5/d/9/5d9bb5b2-49c7-4890-94ab-d1d5e44a0e6d/Install_MSN_Messenger.exe
.. http://messenger.msn.com
Client disconnects from server, since it sees that minimum-allowed is above it's client-version.
Invalid client identification or version
This response may or may not disconnect you.
C: CVR 3 0x0409 winnt 5.0 i386 MSNMSGR 99.9.9999 MSMSGS
S: 420 3
C: CVR 4 0x0409 winnt 5.0 i386 YCOMM 0.1.0023 MSMSGS
S: 420 4
Invalid language ID
C: CVR 5 0x1111 winnt 5.1 MSNMSGR 6.0.0602 MSMSGS example@hotmail.com
S: 710 5
Invalid CVR
C: CVR 6 spaghetti
S: 731 6
Server disconnects client.