Error Messages

Protocol error and failure notifications. More...

Collaboration diagram for Error Messages:

Variables
const char *const	kMsgEIncompatible
	Incompatible protocol versions.
const char *const	kMsgEBusy
	Client name already in use.
const char *const	kMsgEUnknown
	Unknown client name.
const char *const	kMsgEBad
	Protocol violation.

Detailed Description

Protocol error and failure notifications.

Variable Documentation

kMsgEBad

const char* const kMsgEBad

extern

Protocol violation.

Message Code: "EBAD" Direction: Primary → Secondary Format: No parameters

Sent when the client violates the protocol in some way. This can include:

• Sending malformed messages
• Sending messages in wrong order
• Sending unexpected message types
• Exceeding protocol limits

After sending this message, the server will immediately disconnect the client. This indicates a serious protocol error that cannot be recovered from.

Common Causes:

• Implementation bugs in client
• Corrupted network data
• Version mismatch not caught earlier
• Malicious or broken client

Since

Protocol version 1.0

kMsgEBusy

const char* const kMsgEBusy

extern

Client name already in use.

Message Code: "EBSY" Direction: Primary → Secondary Format: No parameters

Sent when the client name provided during connection is already in use by another connected client. Client names must be unique within a Deskflow network.

After receiving this message, the client should:

1. Disconnect from the server
2. Inform the user of the name conflict
3. Allow the user to choose a different name
4. Retry connection with the new name

Since

Protocol version 1.0

kMsgEIncompatible

const char* const kMsgEIncompatible

extern

Incompatible protocol versions.

Message Code: "EICV" Direction: Primary → Secondary Format: "EICV%2i%2i" Parameters:

• $1: Primary major version (2 bytes)
• $2: Primary minor version (2 bytes)

Example:

Server is version 1.8

"EICV\x00\x01\x00\x08"

Sent when the client and server have incompatible protocol versions. This typically occurs when:

• Major versions differ (fundamental incompatibility)
• Server requires newer features than client supports

After sending this message, the server will disconnect the client. The client should display an appropriate error message to the user.

Since

Protocol version 1.0

kMsgEUnknown

const char* const kMsgEUnknown

extern

Unknown client name.

Message Code: "EUNK" Direction: Primary → Secondary Format: No parameters

Sent when the client name provided during connection is not found in the server's screen configuration map. This means the server doesn't know about this client.

This can happen when:

• Client name is misspelled
• Server configuration doesn't include this client
• Client is connecting to wrong server

The client should inform the user and check:

• Client name spelling
• Server configuration
• Network connectivity to correct server

Since

Protocol version 1.0