objects for receive-side socket abstraction specified

The objects for receiver-side socket abstraction have now be
specified. The project as whole does not yet compile and
definitely not run, but I'd like to commit some milestones along
this way.

1 files changed, 222 insertions, 0 deletions

diff --git a/runtime/nssel.c b/runtime/nssel.c
new file mode 100644
index 00000000..f2844872
--- /dev/null
+++ b/runtime/nssel.c
@@ -0,0 +1,222 @@
+/* nssel.c
+ *
+ * The io waiter is a helper object enabling us to wait on a set of streams to become
+ * ready for IO - this is modelled after select(). We need this, because
+ * stream drivers may have different concepts. Consequently,
+ * the structure must contain nsd_t's from the same stream driver type
+ * only. This is implemented as a singly-linked list where every
+ * new element is added at the top of the list.
+ * 
+ * Work on this module begun 2008-04-22 by Rainer Gerhards.
+ *
+ * Copyright 2008 Rainer Gerhards and Adiscon GmbH.
+ *
+ * This file is part of the rsyslog runtime library.
+ *
+ * The rsyslog runtime library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The rsyslog runtime library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the rsyslog runtime library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution.
+ */
+#include "config.h"
+
+#include "rsyslog.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+
+#include "rsyslog.h"
+#include "obj.h"
+#include "module-template.h"
+#include "nssel.h"
+
+MODULE_TYPE_LIB
+
+/* static data */
+DEFobjStaticHelpers
+DEFobjCurrIf(glbl)
+
+
+/* load our low-level driver. This must be done before any
+ * driver-specific functions (allmost all...) can be carried
+ * out. Note that the driver's .ifIsLoaded is correctly
+ * initialized by calloc() and we depend on that.
+ * rgerhards, 2008-04-18
+ */
+static rsRetVal
+loadDrvr(nssel_t *pThis)
+{
+	uchar *pDrvrName;
+	DEFiRet;
+
+	pDrvrName = pThis->pDrvrName;
+	if(pDrvrName == NULL) /* if no drvr name is set, use system default */
+		pDrvrName = glbl.GetDfltNetstrmDrvr();
+
+	pThis->Drvr.ifVersion = nsdCURR_IF_VERSION;
+	/* The pDrvrName+2 below is a hack to obtain the object name. It 
+	 * safes us to have yet another variable with the name without "lm" in
+	 * front of it. If we change the module load interface, we may re-think
+	 * about this hack, but for the time being it is efficient and clean
+	 * enough. -- rgerhards, 2008-04-18
+	 */
+	CHKiRet(obj.UseObj(__FILE__, pDrvrName+2, pDrvrName, (void*) &pThis->Drvr));
+finalize_it:
+	RETiRet;
+}
+
+
+/* Standard-Constructor */
+BEGINobjConstruct(nssel) /* be sure to specify the object type also in END macro! */
+ENDobjConstruct(nssel)
+
+
+/* destructor for the nssel object */
+BEGINobjDestruct(nssel) /* be sure to specify the object type also in END and CODESTART macros! */
+CODESTARTobjDestruct(nssel)
+ENDobjDestruct(nssel)
+
+
+/* ConstructionFinalizer */
+static rsRetVal
+ConstructFinalize(nssel_t *pThis)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, nssel);
+	CHKiRet(loadDrvr(pThis));
+	CHKiRet(pThis->Drvr.Construct(&pThis->pDrvrData));
+finalize_it:
+	RETiRet;
+}
+
+
+/* Add a stream object to the current IOW. Note that a single stream may
+ * have multiple "sockets" if it is a listener. If so, all of them are
+ * begin added.
+ */
+static rsRetVal
+Add(nssel_t *pThis, netstrm_t *pStrm)
+{
+	DEFiRet;
+
+	ISOBJ_TYPE_assert(pThis, nssel);
+	ISOBJ_TYPE_assert(pStrm, netstrm);
+
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* wait for IO to happen on one of our netstreams. iNumReady has
+ * the number of ready "sockets" after the call. This function blocks
+ * until some are ready. EAGAIN is retried.
+ */
+static rsRetVal
+Wait(nssel_t *pThis, int *piNumReady)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, nssel);
+	assert(piNumReady != NULL);
+	RETiRet;
+}
+
+
+/* Check if a stream is ready for IO. *piNumReady contains the remaining number
+ * of ready streams. Note that this function may say the stream is not ready
+ * but still decrement *piNumReady. This can happen when (e.g. with TLS) the low
+ * level driver requires some IO which is hidden from the upper layer point of view.
+ * rgerhards, 2008-04-23
+ */
+static rsRetVal
+IsReady(nssel_t *pThis, netstrm_t *pStrm, int *pbIsReady, int *piNumReady)
+{
+	DEFiRet;
+	ISOBJ_TYPE_assert(pThis, nssel);
+	ISOBJ_TYPE_assert(pStrm, netstrm);
+	assert(pbIsReady != NULL);
+	assert(piNumReady != NULL);
+	RETiRet;
+}
+
+
+/* queryInterface function */
+BEGINobjQueryInterface(nssel)
+CODESTARTobjQueryInterface(nssel)
+	if(pIf->ifVersion != nsselCURR_IF_VERSION) {/* check for current version, increment on each change */
+		ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED);
+	}
+
+	/* ok, we have the right interface, so let's fill it
+	 * Please note that we may also do some backwards-compatibility
+	 * work here (if we can support an older interface version - that,
+	 * of course, also affects the "if" above).
+	 */
+	pIf->Construct = nsselConstruct;
+	pIf->ConstructFinalize = ConstructFinalize;
+	pIf->Destruct = nsselDestruct;
+	pIf->Add = Add;
+	pIf->Wait = Wait;
+	pIf->IsReady = IsReady;
+finalize_it:
+ENDobjQueryInterface(nssel)
+
+
+/* exit our class
+ */
+BEGINObjClassExit(nssel, OBJ_IS_LOADABLE_MODULE) /* CHANGE class also in END MACRO! */
+CODESTARTObjClassExit(nssel)
+	/* release objects we no longer need */
+	objRelease(glbl, CORE_COMPONENT);
+ENDObjClassExit(nssel)
+
+
+/* Initialize the nssel class. Must be called as the very first method
+ * before anything else is called inside this class.
+ * rgerhards, 2008-02-19
+ */
+BEGINObjClassInit(nssel, 1, OBJ_IS_CORE_MODULE) /* class, version */
+	/* request objects we use */
+	CHKiRet(objUse(glbl, CORE_COMPONENT));
+
+	/* set our own handlers */
+ENDObjClassInit(nssel)
+
+
+/* --------------- here now comes the plumbing that makes us a library module --------------- */
+
+
+BEGINmodExit
+CODESTARTmodExit
+	nsselClassExit();
+ENDmodExit
+
+
+BEGINqueryEtryPt
+CODESTARTqueryEtryPt
+CODEqueryEtryPt_STD_LIB_QUERIES
+ENDqueryEtryPt
+
+
+BEGINmodInit()
+CODESTARTmodInit
+	*ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
+
+	/* Initialize all classes that are in our module - this includes ourselfs */
+	CHKiRet(nsselClassInit(pModInfo)); /* must be done after tcps_sess, as we use it */
+ENDmodInit
+/* vi:set ai:
+ */