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Diffstat (limited to 'PM_spec')
| -rw-r--r-- | PM_spec | 153 |
1 files changed, 153 insertions, 0 deletions
@@ -0,0 +1,153 @@ + Proxy Management Protocol + Draft Version 1.0 + Ralph Mor, X Consortium + + +The Proxy Management Protocol is an ICE based protocol that provides a way +for application servers to easily locate proxy services available to them. + +Typically, a service called a "proxy manager" is responsible for resolving +requests for proxy services, starting new proxies when appropriate, and +keeping track of all of the available proxy services. The proxy manager +strives to reuse existing proxies whenever possible. + +In order to request a proxy service, the GET_PROXY_ADDR message is sent to +the proxy manager. The proxy manager will in turn forward this message to +a proxy that it thinks can satisfy the request. + +GET_PROXY_ADDR + proxy-service : STRING + server-address : STRING + host-address : STRING + options : STRING + auth-data-len : CARD16 + auth-name : STRING or None + auth-data : LISTofCARD8 or None + + --> + + status : CARD8 + proxy-address : STRING + failure-reason : STRING + + +proxy-service is the name of the proxy service to be requested, for example +"LBX". proxy-service is a case insensitive string. + +server-address is the network address of the target server. The format of +the address is specific to proxy-service. For example, for a proxy service +of "LBX", the address would be an X display address (e.g, "wkstn.x.org:0"). + +host-address is the network address of the host on which the proxied +application will run. This information might be used by the proxy to +restrict access to a specific host. + +options are proxy specific options that will be passed to the proxy. The +details of these options are not specified here. Their syntax and +semantics are defined by each proxy service. + +If auth-data-len is nonzero, then auth-name and auth-data contain +authentication or authorization information that should be passed to +the proxy. The proxy will typically use this to authenticate and +authorize itself to the target server. The details of how the +auth fields are used are specific to each proxy service. + + +After sending GET_PROXY_ADDR the proxy manager expects a reply from +the proxy. The status field of the reply indicates if the request can +be satisfied. + +If status is Success, proxy-address will contain the network address of the +proxy willing to handle this request. The format of the proxy address is +specific to the proxy service being used. For example, for a proxy service +of "LBX", the proxy address would be the X display address of the proxy +(e.g, "gateway.x.org:63"). The proxy manager will forward the successful +GET_PROXY_ADDR reply to whomever requested the proxy service. + +If status is Unable, the proxy is not able to satisfy the request but +it believes some other proxy might be able to do so. Proxy-address is +the empty string and failure-reason indicates the reason for failure. +The proxy manager may choose to forward the original GET_PROXY_ADDR to +another already running proxy, or it may choose to start up a new +proxy. In the event that the proxy manager can not find or start a +proxy, it will send a GET_PROXY_ADDR reply (with status Failure and an +appropriate failure-reason) to whomever requested the proxy service. + +If status is Failure, the proxy is not able to satisfy the request and +in addition is informing the requester that the request is invalid in +some way and should not be retried. + + +If the proxy manager starts up a new proxy, the proxy manager will +need an indication from the proxy that it is ready to accept +requests. The proxy is required to send a START_PROXY message to the +proxy manager to identify itself and signal its readiness to receive +requests. + +START_PROXY + proxy-service : STRING (name of proxy service, e.g. "LBX") + + +When the proxy manager receives the START_PROXY message from the +proxy it checks that the proxy-service is the one that it's expecting. +If the proxy-service is incorrect, an IceBadValue error will be sent +to the proxy. Otherwise, the proxy manager will forward the original +GET_PROXY_ADDR request to the proxy and the proxy will respond to the +GET_PROXY_ADDR request in the same way as discussed above. + + +Protocol +-------- + +ICE protocol name is "PROXY_MANAGEMENT". +The major opcode is assigned at run-time by ICE. + + +Types +----- + +STRING + 2 CARD16 length + n LISTofCARD8 the string + p p = pad(2+n,8) + + + +Encoding +-------- + +GET_PROXY_ADDR + + 1 ? PROXY_MANAGEMENT + 1 1 opcode + 2 n auth-data-len (in bytes) + 4 (a+b+c+d+e+n+p)/8 length of remaining data in 8-byte units + a STRING proxy-service + b STRING server-address + c STRING host-address + d STRING options + e STRING auth-name (if auth-data-len > 0) + n LISTofCARD8 auth-data (if auth-data-len > 0) + p unused, p=pad(n,8) + +GET_PROXY_ADDR_REPLY + + 1 ? PROXY_MANAGEMENT + 1 2 opcode + 1 CARD8 status + 0 Unable + 1 Success + 2 Failure + 1 unused + 4 (a+b)/8 length of remaining data in 8-byte units + a STRING proxy-address + b STRING failure-reason + + +START_PROXY + + 1 ? PROXY_MANAGEMENT + 1 3 opcode + 2 unused + 4 a/8 length of remaining data in 8-byte units + a STRING proxy-service |