[libvirt] [PATCH 2/9] Decode incoming request header before invoking dispatch code
Daniel P. Berrange
berrange at redhat.com
Tue Jul 14 10:17:52 UTC 2009
Separate the decoding of incoming request header out from the
dispatch code. This will allow later code to making dispatcher
routing decisions based on the header field data.
* qemud/dispatch.c, qemud/dispatch.h: Add remoteDecodeClientMessageHeader
API for decoding the header of a client message. Update the
remoteDispatchClientRequest method to assume a pre-decoded
header.
* qemud/qemud.h: Include a 'remote_message_header' field in
'struct qemud_client_message' for pre-decoded header data
* qemud/qemud.c: Decode the incoming client message header before
invoking remoteDispatchClientRequest
Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
qemud/dispatch.c | 96 ++++++++++++++++++++++++++++++++++++-----------------
qemud/dispatch.h | 3 ++
qemud/qemud.c | 3 +-
qemud/qemud.h | 2 +
4 files changed, 72 insertions(+), 32 deletions(-)
diff --git a/qemud/dispatch.c b/qemud/dispatch.c
index d2338fb..127f93b 100644
--- a/qemud/dispatch.c
+++ b/qemud/dispatch.c
@@ -124,13 +124,50 @@ void remoteDispatchConnError (remote_error *rerr,
/*
+ * @msg: the complete incoming message, whose header to decode
+ *
+ * Decodes the header part of the client message, but does not
+ * validate the decoded fields in the header.
+ *
+ * returns 0 if successfully decoded, -1 upon fatal error
+ */
+int
+remoteDecodeClientMessageHeader (struct qemud_client_message *msg)
+{
+ XDR xdr;
+ int ret = -1;
+
+ msg->bufferOffset = REMOTE_MESSAGE_HEADER_XDR_LEN;
+
+ /* Parse the header. */
+ xdrmem_create (&xdr,
+ msg->buffer + msg->bufferOffset,
+ msg->bufferLength - msg->bufferOffset,
+ XDR_DECODE);
+
+ if (!xdr_remote_message_header (&xdr, &msg->hdr))
+ goto cleanup;
+
+ msg->bufferOffset += xdr_getpos(&xdr);
+
+ ret = 0;
+
+cleanup:
+ xdr_destroy(&xdr);
+ return ret;
+}
+
+
+/*
* @server: the unlocked server object
* @client: the locked client object
- * @msg: the complete incoming message packet
+ * @msg: the complete incoming message packet, with header already decoded
*
* This function gets called from qemud when it pulls a incoming
* remote protocol messsage off the dispatch queue for processing.
*
+ * The @msg parameter must have had its header decoded already by
+ * calling remoteDecodeClientMessageHeader
*
* Returns 0 if the message was dispatched, -1 upon fatal error
*/
@@ -140,7 +177,7 @@ remoteDispatchClientRequest (struct qemud_server *server,
struct qemud_client_message *msg)
{
XDR xdr;
- remote_message_header req, rep;
+ remote_message_header rep;
remote_error rerr;
dispatch_args args;
dispatch_ret ret;
@@ -153,36 +190,28 @@ remoteDispatchClientRequest (struct qemud_server *server,
memset(&ret, 0, sizeof ret);
memset(&rerr, 0, sizeof rerr);
- /* Parse the header. */
- xdrmem_create (&xdr,
- msg->buffer + REMOTE_MESSAGE_HEADER_XDR_LEN,
- msg->bufferLength - REMOTE_MESSAGE_HEADER_XDR_LEN,
- XDR_DECODE);
-
- if (!xdr_remote_message_header (&xdr, &req))
- goto fatal_error;
/* Check version, etc. */
- if (req.prog != REMOTE_PROGRAM) {
+ if (msg->hdr.prog != REMOTE_PROGRAM) {
remoteDispatchFormatError (&rerr,
_("program mismatch (actual %x, expected %x)"),
- req.prog, REMOTE_PROGRAM);
+ msg->hdr.prog, REMOTE_PROGRAM);
goto rpc_error;
}
- if (req.vers != REMOTE_PROTOCOL_VERSION) {
+ if (msg->hdr.vers != REMOTE_PROTOCOL_VERSION) {
remoteDispatchFormatError (&rerr,
_("version mismatch (actual %x, expected %x)"),
- req.vers, REMOTE_PROTOCOL_VERSION);
+ msg->hdr.vers, REMOTE_PROTOCOL_VERSION);
goto rpc_error;
}
- if (req.direction != REMOTE_CALL) {
+ if (msg->hdr.direction != REMOTE_CALL) {
remoteDispatchFormatError (&rerr, _("direction (%d) != REMOTE_CALL"),
- (int) req.direction);
+ (int) msg->hdr.direction);
goto rpc_error;
}
- if (req.status != REMOTE_OK) {
+ if (msg->hdr.status != REMOTE_OK) {
remoteDispatchFormatError (&rerr, _("status (%d) != REMOTE_OK"),
- (int) req.status);
+ (int) msg->hdr.status);
goto rpc_error;
}
@@ -190,11 +219,11 @@ remoteDispatchClientRequest (struct qemud_server *server,
* except for authentication ones
*/
if (client->auth) {
- if (req.proc != REMOTE_PROC_AUTH_LIST &&
- req.proc != REMOTE_PROC_AUTH_SASL_INIT &&
- req.proc != REMOTE_PROC_AUTH_SASL_START &&
- req.proc != REMOTE_PROC_AUTH_SASL_STEP &&
- req.proc != REMOTE_PROC_AUTH_POLKIT
+ if (msg->hdr.proc != REMOTE_PROC_AUTH_LIST &&
+ msg->hdr.proc != REMOTE_PROC_AUTH_SASL_INIT &&
+ msg->hdr.proc != REMOTE_PROC_AUTH_SASL_START &&
+ msg->hdr.proc != REMOTE_PROC_AUTH_SASL_STEP &&
+ msg->hdr.proc != REMOTE_PROC_AUTH_POLKIT
) {
/* Explicitly *NOT* calling remoteDispatchAuthError() because
we want back-compatability with libvirt clients which don't
@@ -204,19 +233,25 @@ remoteDispatchClientRequest (struct qemud_server *server,
}
}
- data = remoteGetDispatchData(req.proc);
+ data = remoteGetDispatchData(msg->hdr.proc);
if (!data) {
remoteDispatchFormatError (&rerr, _("unknown procedure: %d"),
- req.proc);
+ msg->hdr.proc);
goto rpc_error;
}
- /* De-serialize args off the wire */
+ /* De-serialize payload with args from the wire message */
+ xdrmem_create (&xdr,
+ msg->buffer + msg->bufferOffset,
+ msg->bufferLength - msg->bufferOffset,
+ XDR_DECODE);
if (!((data->args_filter)(&xdr, &args))) {
+ xdr_destroy (&xdr);
remoteDispatchFormatError (&rerr, "%s", _("parse args failed"));
goto rpc_error;
}
+ xdr_destroy (&xdr);
/* Call function. */
conn = client->conn;
@@ -241,14 +276,13 @@ remoteDispatchClientRequest (struct qemud_server *server,
xdr_free (data->args_filter, (char*)&args);
rpc_error:
- xdr_destroy (&xdr);
/* Return header. */
- rep.prog = req.prog;
- rep.vers = req.vers;
- rep.proc = req.proc;
+ rep.prog = msg->hdr.prog;
+ rep.vers = msg->hdr.vers;
+ rep.proc = msg->hdr.proc;
rep.direction = REMOTE_REPLY;
- rep.serial = req.serial;
+ rep.serial = msg->hdr.serial;
rep.status = rv < 0 ? REMOTE_ERROR : REMOTE_OK;
/* Serialise the return header. */
diff --git a/qemud/dispatch.h b/qemud/dispatch.h
index 9ab6148..db372f1 100644
--- a/qemud/dispatch.h
+++ b/qemud/dispatch.h
@@ -29,6 +29,9 @@
int
+remoteDecodeClientMessageHeader (struct qemud_client_message *req);
+
+int
remoteDispatchClientRequest (struct qemud_server *server,
struct qemud_client *client,
struct qemud_client_message *req);
diff --git a/qemud/qemud.c b/qemud/qemud.c
index d300c56..c577d88 100644
--- a/qemud/qemud.c
+++ b/qemud/qemud.c
@@ -1458,7 +1458,8 @@ static void *qemudWorker(void *data)
/* This function drops the lock during dispatch,
* and re-acquires it before returning */
- if (remoteDispatchClientRequest (server, client, reply) < 0) {
+ if (remoteDecodeClientMessageHeader(reply) < 0 ||
+ remoteDispatchClientRequest (server, client, reply) < 0) {
VIR_FREE(reply);
qemudDispatchClientFailure(client);
client->refs--;
diff --git a/qemud/qemud.h b/qemud/qemud.h
index c8273cb..6597429 100644
--- a/qemud/qemud.h
+++ b/qemud/qemud.h
@@ -85,6 +85,8 @@ struct qemud_client_message {
int async : 1;
+ remote_message_header hdr;
+
struct qemud_client_message *next;
};
--
1.6.2.5
--
|: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :|
|: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :|
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