Method and system for avoiding an unintentional time-out for communications in a client-proxy-server environment
View Patent ↗When conducting anti-virus, anti-spam, or other content filtering on a gateway device, data traffic is run through a proxy that completes a “fetch-scan-forward” operation of the data traffic exchanged between a server and a client. During the transmission of data from the server to the proxy and while the gateway is scanning the data, the client is idle and in danger of timing-out and aborting the data request to be received from the proxy. To prevent this, the proxy sends an intervention message, typically in the form of an extension header file, continuation response, and/or innocuous command, in advance of the client-side time-out. Alternatively, during the transmission of data from the client to the proxy and while the gateway is scanning the data, the server is idle and in danger of timing-out. A proxy sends an intervention message, in the form of an innocuous command, in advance of the server-side time-out.
1. A computer-implemented method for avoiding unintentional client-side time-outs, comprising the steps of:
receiving at a proxy requested data from a server;
transmitting at least one intervention message from the proxy to a client while the proxy waits to receive the requested data from the server, the intervention message comprising content other than the requested data received from the server;
determining at the proxy whether the requested data comprises one of a plurality of security violations; and
transmitting at least one intervention message from the proxy to the client while determining whether the requested data comprises a security violation, the intervention message comprising content other than the requested data received from the server, wherein transmitting the at least one intervention message comprises transmitting one or more of:
a single line of data traffic comprising content other than the requested data received from the server, that is included at the front of a mail header;
a single line of data traffic comprising content other than the requested data received from the server, that is included within standard header fields; and
a protocol command comprising content other than the requested data received from the server, that is unrelated to the requested data.
2. The method of claim 1 wherein the step of transmitting the intervention message comprises transmitting one or more of
an extension header field; and
an innocuous command.
3. The method of claim 1 wherein the step of transmitting the intervention message is performed prior to a time-out of a client reset timer.
4. The method of claim 1 further comprising the step of transmitting the requested data to the client after determining at the proxy whether the requested data comprises one of a plurality of security violations.
5. A computer-implemented method for avoiding unintentional server-side time-outs, comprising the steps of:
receiving at a proxy requested data from a client;
transmitting at least one intervention message from a proxy to a server while the proxy waits to receive all of the requested data from the client, wherein the intervention message is transmitted prior to a time-out of a server reset timer;
determining at the proxy whether the requested data comprises one of a plurality of security violations; and
transmitting at least one intervention message from the proxy to the server while determining whether the requested data comprises a security violation, the intervention message comprising content other than the requested data received from the client.
6. The method of claim 5 wherein the step of transmitting the intervention message comprises one or more of
an extension header field;
a continuation response; and
an innocuous command.
7. The method of claim 5 wherein the step of transmitting the intervention message comprises transmitting one or more of
a single line of data traffic comprising content other than the requested data received from the client, that is included at the front of a mail header;
a single line of data traffic comprising content other than the requested data received from the client, that is included within standard header fields;
a multi-line status response comprising content other than the requested data received from the client, that is generated by the proxy from a FTP response; and
a protocol command comprising content other than the requested data received from the client, that is unrelated to the requested data.
8. The method of claim 5 further comprising the step of transmitting the requested data to the server after determining at the proxy whether the requested data comprises one of a plurality of security violations.
9. A system for avoiding unintentional client-side time-outs, comprising:
a server operative to transmit requested data; and
at least one proxy operative to
receive the requested data from the server,
to transmit at least one intervention message to a client while waiting to receive the requested data from the server and prior to a time-out of a client reset timer,
determine at the proxy whether the requested data comprises one of a plurality of security violations, and
transmit at least one intervention message from the proxy to the client while determining whether the requested data comprises a security violation, the intervention message comprising content other than the requested data received from the server.
10. The system of claim 9 , wherein the intervention message transmitted by the proxy comprises one or more of
an extension header field; and
an innocuous command.
11. The system of claim 9 , wherein the intervention message transmitted by the proxy comprises one or more of
a single line of data traffic comprising content other than the requested data received from the server, that is included at the front of a mail header;
a single line of data traffic comprising content other than the requested data received from the server, that is included within standard header fields; and
a protocol command comprising content other than the requested data received from the server, that is unrelated to the requested data.
12. The system of claim 9 , wherein the proxy comprises one of a HTTP proxy, a POP3 proxy, and a FTP proxy.
13. A system for avoiding unintentional server-side time-outs, comprisin
a client operative to transmit requested data;
at least one proxy operative to
receive the requested data from the client,
transmit at least one intervention message to a server while waiting to receive the requested data from the client, the intervention message comprising content other than requested data received from the client,
determine at the proxy whether the requested data comprises one of a plurality of security violations, and
transmit at least one intervention message from the proxy to the server while determining whether the requested data comprises a security violation, the intervention message comprising content other than the requested data received from the client.
14. The system of claim 13 , wherein the intervention message transmitted by the proxy comprises one or more of
an extension header field;
a continuation response; and
an innocuous command.
15. The system of claim 13 , wherein the intervention message transmitted by the proxy comprises one or more of
a single line of data traffic comprising content other than the requested data received from the client, that is included at the front of a mail header;
a single line of data traffic comprising content other than the requested data received from the client, that is included within standard header fields;
a multi-line status response comprising content other than the requested data received from the client, that is generated by the proxy from a FTP response; and
a protocol command comprising content other than the requested data received from the client, that is unrelated to the requested data.
16. The system of claim 13 , wherein the proxy transmits the intervention message prior to a time-out of a server reset timer.
17. The system of claim 13 , wherein the proxy comprises one of a HTTP proxy, a POP3 proxy, and a FTP proxy.