1 files changed, 290 insertions, 0 deletions
diff --git a/runtime/nsdpoll_ptcp.c b/runtime/nsdpoll_ptcp.c
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+++ b/runtime/nsdpoll_ptcp.c
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+/* nsdpoll_ptcp.c
+ *
+ * An implementation of the nsd epoll() interface for plain tcp sockets.
+ * 
+ * Copyright 2009 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"
+
+#ifdef HAVE_EPOLL_CREATE /* this module requires epoll! */
+
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#if HAVE_SYS_EPOLL_H
+#	include <sys/epoll.h>
+#endif
+
+#include "rsyslog.h"
+#include "module-template.h"
+#include "obj.h"
+#include "errmsg.h"
+#include "srUtils.h"
+#include "nspoll.h"
+#include "nsd_ptcp.h"
+#include "nsdpoll_ptcp.h"
+
+/* static data */
+DEFobjStaticHelpers
+DEFobjCurrIf(errmsg)
+DEFobjCurrIf(glbl)
+
+
+/* -START------------------------- helpers for event list ------------------------------------ */
+
+/* add new entry to list. We assume that the fd is not already present and DO NOT check this!
+ * Returns newly created entry in pEvtLst.
+ * Note that we currently need to use level-triggered mode, because the upper layers do not work
+ * in parallel. As such, in edge-triggered mode we may not get notified, because new data comes
+ * in after we have read everything that was present. To use ET mode, we need to change the upper
+ * peers so that they immediately start a new wait before processing the data read. That obviously
+ * requires more elaborate redesign and we postpone this until the current more simplictic mode has
+ * been proven OK in practice.
+ * rgerhards, 2009-11-18
+ */
+static inline rsRetVal
+addEvent(nsdpoll_ptcp_t *pThis, int id, void *pUsr, int mode, nsd_ptcp_t *pSock, nsdpoll_epollevt_lst_t **pEvtLst) {
+	nsdpoll_epollevt_lst_t *pNew;
+	DEFiRet;
+
+	CHKmalloc(pNew = (nsdpoll_epollevt_lst_t*) malloc(sizeof(nsdpoll_epollevt_lst_t)));
+	pNew->id = id;
+	pNew->pUsr = pUsr;
+	pNew->pSock = pSock;
+	pNew->event.events = 0; /* TODO: at some time we should be able to use EPOLLET */
+	if(mode & NSDPOLL_IN)
+		pNew->event.events |= EPOLLIN;
+	if(mode & NSDPOLL_OUT)
+		pNew->event.events |= EPOLLOUT;
+	pNew->event.data.u64 = (uint64) pNew;
+	pNew->pNext = pThis->pRoot;
+	pThis->pRoot = pNew;
+	*pEvtLst = pNew;
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* find and unlink the entry identified by id/pUsr from the list.
+ * rgerhards, 2009-11-23
+ */
+static inline rsRetVal
+unlinkEvent(nsdpoll_ptcp_t *pThis, int id, void *pUsr, nsdpoll_epollevt_lst_t **ppEvtLst) {
+	nsdpoll_epollevt_lst_t *pEvtLst;
+	nsdpoll_epollevt_lst_t *pPrev = NULL;
+	DEFiRet;
+
+	pEvtLst = pThis->pRoot;
+	while(pEvtLst != NULL && !(pEvtLst->id == id && pEvtLst->pUsr == pUsr)) {
+		pPrev = pEvtLst;
+		pEvtLst = pEvtLst->pNext;
+	}
+	if(pEvtLst == NULL)
+		ABORT_FINALIZE(RS_RET_NOT_FOUND);
+
+	*ppEvtLst = pEvtLst;
+
+	/* unlink */
+	if(pPrev == NULL)
+		pThis->pRoot = pEvtLst->pNext;
+	else
+		pPrev->pNext = pEvtLst->pNext;
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* destruct the provided element. It must already be unlinked from the list.
+ * rgerhards, 2009-11-23
+ */
+static inline rsRetVal
+delEvent(nsdpoll_epollevt_lst_t **ppEvtLst) {
+	DEFiRet;
+	free(*ppEvtLst);
+	*ppEvtLst = NULL;
+	RETiRet;
+}
+
+
+/* -END--------------------------- helpers for event list ------------------------------------ */
+
+
+/* Standard-Constructor
+ */
+BEGINobjConstruct(nsdpoll_ptcp) /* be sure to specify the object type also in END macro! */
+#if defined(EPOLL_CLOEXEC) && defined(HAVE_EPOLL_CREATE1)
+	DBGPRINTF("nsdpoll_ptcp uses epoll_create1()\n");
+	pThis->efd = epoll_create1(EPOLL_CLOEXEC);
+	if(pThis->efd < 0 && errno == ENOSYS)
+#endif
+	{
+		DBGPRINTF("nsdpoll_ptcp uses epoll_create()\n");
+		pThis->efd = epoll_create(100); /* size is ignored in newer kernels, but 100 is not bad... */
+	}
+
+	if(pThis->efd < 0) {
+		DBGPRINTF("epoll_create1() could not create fd\n");
+		ABORT_FINALIZE(RS_RET_IO_ERROR);
+	}
+finalize_it:
+ENDobjConstruct(nsdpoll_ptcp)
+
+
+/* destructor for the nsdpoll_ptcp object */
+BEGINobjDestruct(nsdpoll_ptcp) /* be sure to specify the object type also in END and CODESTART macros! */
+CODESTARTobjDestruct(nsdpoll_ptcp)
+ENDobjDestruct(nsdpoll_ptcp)
+
+
+/* Modify socket set */
+static rsRetVal
+Ctl(nsdpoll_t *pNsdpoll, nsd_t *pNsd, int id, void *pUsr, int mode, int op) {
+	nsdpoll_ptcp_t *pThis = (nsdpoll_ptcp_t*) pNsdpoll;
+	nsd_ptcp_t *pSock = (nsd_ptcp_t*) pNsd;
+	nsdpoll_epollevt_lst_t *pEventLst;
+	int errSave;
+	char errStr[512];
+	DEFiRet;
+
+	if(op == NSDPOLL_ADD) {
+		dbgprintf("adding nsdpoll entry %d/%p, sock %d\n", id, pUsr, pSock->sock);
+		CHKiRet(addEvent(pThis, id, pUsr, mode, pSock, &pEventLst));
+		if(epoll_ctl(pThis->efd, EPOLL_CTL_ADD,  pSock->sock, &pEventLst->event) < 0) {
+			errSave = errno;
+			rs_strerror_r(errSave, errStr, sizeof(errStr));
+			errmsg.LogError(errSave, RS_RET_ERR_EPOLL_CTL,
+				"epoll_ctl failed on fd %d, id %d/%p, op %d with %s\n",
+				pSock->sock, id, pUsr, mode, errStr);
+		}
+	} else if(op == NSDPOLL_DEL) {
+		dbgprintf("removing nsdpoll entry %d/%p, sock %d\n", id, pUsr, pSock->sock);
+		CHKiRet(unlinkEvent(pThis, id, pUsr, &pEventLst));
+		if(epoll_ctl(pThis->efd, EPOLL_CTL_DEL, pSock->sock, &pEventLst->event) < 0) {
+			errSave = errno;
+			rs_strerror_r(errSave, errStr, sizeof(errStr));
+			errmsg.LogError(errSave, RS_RET_ERR_EPOLL_CTL,
+				"epoll_ctl failed on fd %d, id %d/%p, op %d with %s\n",
+				pSock->sock, id, pUsr, mode, errStr);
+			ABORT_FINALIZE(RS_RET_ERR_EPOLL_CTL);
+		}
+		CHKiRet(delEvent(&pEventLst));
+	} else {
+		dbgprintf("program error: invalid NSDPOLL_mode %d - ignoring request\n", op);
+		ABORT_FINALIZE(RS_RET_ERR);
+	}
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* Wait for io to become ready. After the successful call, idRdy contains the
+ * id set by the caller for that i/o event, ppUsr is a pointer to a location
+ * where the user pointer shall be stored.
+ * TODO: this is a trivial implementation that only polls one event at a time. We
+ *       may later extend it to poll for multiple events, what would cause less 
+ *       overhead.
+ * rgerhards, 2009-11-18
+ */
+static rsRetVal
+Wait(nsdpoll_t *pNsdpoll, int timeout, int *idRdy, void **ppUsr) {
+	nsdpoll_ptcp_t *pThis = (nsdpoll_ptcp_t*) pNsdpoll;
+	nsdpoll_epollevt_lst_t *pOurEvt;
+	struct epoll_event event;
+	int nfds;
+	DEFiRet;
+
+	assert(idRdy != NULL);
+	assert(ppUsr != NULL);
+
+	nfds = epoll_wait(pThis->efd, &event, 1, timeout);
+	if(nfds == -1) {
+		if(errno == EINTR) {
+			ABORT_FINALIZE(RS_RET_EINTR);
+		} else {
+			DBGPRINTF("epoll() returned with error code %d\n", errno);
+			ABORT_FINALIZE(RS_RET_ERR_EPOLL);
+		}
+	} else if(nfds == 0) {
+		ABORT_FINALIZE(RS_RET_TIMEOUT);
+	}
+
+	/* we got a valid event, so tell the caller... */
+	pOurEvt = (nsdpoll_epollevt_lst_t*) event.data.u64;
+	*idRdy = pOurEvt->id;
+	*ppUsr = pOurEvt->pUsr;
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* ------------------------------ end support for the epoll() interface ------------------------------ */
+
+
+/* queryInterface function */
+BEGINobjQueryInterface(nsdpoll_ptcp)
+CODESTARTobjQueryInterface(nsdpoll_ptcp)
+	if(pIf->ifVersion != nsdCURR_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 = (rsRetVal(*)(nsdpoll_t**)) nsdpoll_ptcpConstruct;
+	pIf->Destruct = (rsRetVal(*)(nsdpoll_t**)) nsdpoll_ptcpDestruct;
+	pIf->Ctl = Ctl;
+	pIf->Wait = Wait;
+finalize_it:
+ENDobjQueryInterface(nsdpoll_ptcp)
+
+
+/* exit our class
+ */
+BEGINObjClassExit(nsdpoll_ptcp, OBJ_IS_CORE_MODULE) /* CHANGE class also in END MACRO! */
+CODESTARTObjClassExit(nsdpoll_ptcp)
+	/* release objects we no longer need */
+	objRelease(glbl, CORE_COMPONENT);
+	objRelease(errmsg, CORE_COMPONENT);
+ENDObjClassExit(nsdpoll_ptcp)
+
+
+/* Initialize the nsdpoll_ptcp class. Must be called as the very first method
+ * before anything else is called inside this class.
+ * rgerhards, 2008-02-19
+ */
+BEGINObjClassInit(nsdpoll_ptcp, 1, OBJ_IS_CORE_MODULE) /* class, version */
+	/* request objects we use */
+	CHKiRet(objUse(errmsg, CORE_COMPONENT));
+	CHKiRet(objUse(glbl, CORE_COMPONENT));
+
+	/* set our own handlers */
+ENDObjClassInit(nsdpoll_ptcp)
+#endif /* #ifdef HAVE_EPOLL_CREATE this module requires epoll! */
+
+/* vi:set ai:
+ */