2.3 Communication in the Network .............................. 6
2.4 Channel Communication ..................................... 7
2.5 Router Connections ........................................ 7
+ 2.6 Backup Routers ............................................ XX
3 SILC Specification ............................................ 8
3.1 Client .................................................... 8
3.1.1 Client ID ........................................... 9
distributed by SILC broadcast packets.
+.ti 0
+2.6 Backup Routers
+
+Backup routers may exist in the cell in addition of the primary router.
+However, they must not be active routers and act as routers in the cell.
+Only one router may be acting as primary router in the cell. In the case
+of failure of the primary router may one of the backup routers become
+active. The purpose of backup routers are in case of failure of the
+primary router to maintain working connections inside the cell and outside
+the cell and to avoid netsplits.
+
+Backup routers are normal servers in the cell that are prepared to take
+over the tasks of primary router if needed. They need to have at least
+one direct and active connection to the primary router of the cell.
+This communication channel is used to send the router information to
+the backup router. Backup router must know everything that the primary
+router knows to be able to take over the tasks of the primary router.
+It is the primary router's responsibility to feed the data to the backup
+router. If the backup router does not know all the data in the case of
+failure some connections may be lost. The primary router of the cell
+must consider the backup router being normal router server and feed the
+data accordingly.
+
+In addition of having direct connection to the primary router of the
+cell the backup router must also have connection to the same router
+the primary router of the cell has connected. However, it must not be
+active router connection meaning that the backup router must not use
+that channel as its primary route and it must not notify the router
+about having connected servers, channels and clients behind it. It
+merely connects to the router. This sort of connection is later
+referred as being passive connection. Some keepalive actions may be
+needed by the router to keep the connection alive.
+
+The primary router notifies its primary router about having backup
+routers in the cell by sending SILC_PACKET_CELL_ROUTERS packet. If
+and when the primary router of the cell becomes unresponsive, its
+primary router knows that there exists backup routers in the cell.
+After that it will start using the first backup router sent in the
+packet as router of that cell. In this case the backup router must
+notify its new primary router about the servers, channels and clients
+it has connected to it. The primary router knows that this server
+has become a router of the cell because of failure of the primary
+router in the cell. It must also cope with the fact that the servers,
+channels and clients that the new backup router announces are not
+really new, since they used to exist in the primary router of the
+cell.
+
+It is required that other normal servers has passive connections to
+the backup router(s) in the cell. Some keepalive actions may be needed
+by the server to keep the connection alive. After they notice the
+failure of the primary router they must start using the connection to
+the first backup router as their primary route.
+
+It is recommended that there would be at least one backup router in
+the cell. It is not recommended to have all servers in the cell acting
+as backup routers as it requires establishing several connections to
+several servers in the cell. Large cells can easily have several
+backup routers in the cell. The order of the backup routers are decided
+at the primary router of the cell and servers and backup servers in the
+cell must be configured accordingly. It is not required that the backup
+server is actually active server in the cell. Backup router may be spare
+server in the cell that does not accept normal client connections at all.
+It maybe reserved purely for the backup purposes. These, however, are
+cell management issues.
+
+If the first backup router is down as well and there is another backup
+router in the cell then it will start acting as the primary router as
+described above.
+
+
.ti 0
3. SILC Specification
It is expected that some of the commands may be miss-used by clients
resulting various problems on the server side. Every implementation
should assure that commands may not be executed more than once, say,
-in two (2) seconds. This should be sufficient to prevent the miss-use
-of commands.
+in two (2) seconds. However, to keep response rate up, allowing for
+example five (5) commands before limiting is allowed. It is recommended
+that commands such as SILC_COMMAND_NICK, SILC_COMMAND_JOIN and
+SILC_COMMAND_LEAVE should be limited in all cases as they require
+heavy operations. This should be sufficient to prevent the miss-use of
+commands.
SILC commands are described in section 5 SILC Commands.
13 SILC_COMMAND_OPER
Max Arguments: 2
- Arguments: (1) <username> (2) <authentication data>
+ Arguments: (1) <username> (2) <authentication payload>
This command is used by normal client to obtain server operator
privileges on some server or router. Note that router operator
must use SILCOPER command to obtain router level privileges.
The <username> is the username set in the server configurations
- as operator. The <authentication data> is the data that the
+ as operator. The <authentication payload> is the data that the
client is authenticated against. It may be passphrase prompted
- for user on client's screen or it may be public key
- authentication data (data signed with private key), or
- certificate.
+ for user on client's screen or it may be public key or certificate
+ authentication data (data signed with private key).
Reply messages to the command:
SILC_STATUS_ERR_NOT_ENOUGH_PARAMS
SILC_STATUS_ERR_TOO_MANY_PARAMS
SILC_STATUS_ERR_NOT_REGISTERED
- SILC_STATUS_ERR_BAD_PASSWORD
SILC_STATUS_ERR_AUTH_FAILED
23 SILC_COMMAND_SILCOPER
Max Arguments: 2
- Arguments: (1) <username> (2) <authentication data>
+ Arguments: (1) <username> (2) <authentication payload>
This command is used by normal client to obtain router operator
privileges (also known as SILC operator) on some router. Note
server operator privileges.
The <username> is the username set in the server configurations
- as operator. The <authentication data> is the data that the
+ as operator. The <authentication payload> is the data that the
client is authenticated against. It may be passphrase prompted
for user on client's screen or it may be public key
authentication data (data signed with private key), or
SILC_STATUS_ERR_NOT_ENOUGH_PARAMS
SILC_STATUS_ERR_TOO_MANY_PARAMS
SILC_STATUS_ERR_NOT_REGISTERED
- SILC_STATUS_ERR_BAD_PASSWORD
SILC_STATUS_ERR_AUTH_FAILED
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