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+/* imsolaris.c
+ * This input module is used to gather local log data under Solaris. This
+ * includes messages from local applications AS WELL AS the kernel log.
+ * I first considered to make all of this available via imklog, but that
+ * did not lock appropriately on second thought. So I created this module
+ * that does anything for local message recption.
+ *
+ * This module is not meant to be used on plaforms other than Solaris. As
+ * such, trying to compile it elswhere will probably fail with all sorts
+ * of errors.
+ *
+ * Some notes on the Solaris syslog mechanism:
+ * Both system (kernel) and application log messages are provided via
+ * a single message stream.
+ *
+ * Solaris checks if the syslogd is running. If so, syslog() emits messages
+ * to the log socket, only. Otherwise, it emits messages to the console.
+ * It is possible to gather these console messages as well. However, then
+ * we clutter the console.
+ * Solaris does this "syslogd alive check" in a somewhat unexpected way
+ * (at least unexpected for me): it uses the so-called "door" mechanism, a
+ * fast RPC facility. I first thought that the door API was used to submit
+ * the actual syslog messages. But this is not the case. Instead, a door
+ * call is done, and the server process inside rsyslog simply does NOTHING
+ * but return. All that Solaris sylsogd() is interested in is if the door
+ * server (we) responds and thus can be considered alive. The actual message
+ * is then submitted via the usual stream. I have to admit I do not
+ * understand why the message itself is not passed via this high-performance
+ * API. But anyhow, that's nothing I can change, so the most important thing
+ * is to note how Solaris does this thing ;)
+ * The syslog() library call checks syslogd state for *each* call (what a
+ * waste of time...) and decides each time if the message should go to the
+ * console or not. According to OpenSolaris sources, it looks like there is
+ * message loss potential when the door file is created before all data has
+ * been pulled from the stream. While I have to admit that I do not fully
+ * understand that problem, I will follow the original code advise and do
+ * one complete pull cycle on the log socket (until it has no further data
+ * available) and only thereafter create the door file and start the "regular"
+ * pull cycle. As of my understanding, there is a minimal race between the
+ * point where the intial pull cycle has ended and the door file is created,
+ * but that race is also present in OpenSolaris syslogd code, so it should
+ * not matter that much (plus, I do not know how to avoid it...)
+ *
+ * File begun on 2010-04-15 by RGerhards
+ *
+ * Copyright 2010 Rainer Gerhards and Adiscon GmbH.
+ *
+ * This file is part of rsyslog.
+ *
+ * Rsyslog is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Rsyslog 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Rsyslog. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ */
+#include "config.h"
+#include "rsyslog.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <assert.h>
+#include <string.h>
+#include <stropts.h>
+#include <sys/strlog.h>
+#include <errno.h>
+#include "dirty.h"
+#include "cfsysline.h"
+#include "unicode-helper.h"
+#include "module-template.h"
+#include "srUtils.h"
+#include "errmsg.h"
+#include "net.h"
+#include "glbl.h"
+#include "msg.h"
+#include "prop.h"
+#include "sun_cddl.h"
+
+MODULE_TYPE_INPUT
+
+/* defines */
+#define PATH_LOG "/dev/log"
+
+
+/* Module static data */
+DEF_IMOD_STATIC_DATA
+DEFobjCurrIf(errmsg)
+DEFobjCurrIf(glbl)
+DEFobjCurrIf(prop)
+
+
+/* config settings */
+static prop_t *pInputName = NULL; /* our inputName currently is always "imuxsock", and this will hold it */
+static char *LogName = NULL; /* the log socket name TODO: make configurable! */
+
+
+/* a function to replace the sun logerror() function.
+ * It generates an error message from the supplied string. The main
+ * reason for not calling logError directly is that sun_cddl.c does not
+ * know or has acces to rsyslog objects (namely errmsg) -- and we do not
+ * want to do this effort. -- rgerhards, 2010-04-19
+ */
+void
+imsolaris_logerror(int err, char *errStr)
+{
+ errmsg.LogError(err, RS_RET_ERR_DOOR, "%s", errStr);
+}
+
+
+/* we try to recover a failed file by closing and re-opening
+ * it. We loop until the re-open works, but wait between each
+ * failure. If the open succeeds, we assume all is well. If it is
+ * not, we will run into the retry process with the next
+ * iteration.
+ * rgerhards, 2010-04-19
+ */
+static void
+tryRecover(void)
+{
+ int tryNum = 1;
+ int waitsecs;
+ int waitusecs;
+ rsRetVal iRet;
+
+ close(sun_Pfd.fd);
+ sun_Pfd.fd = -1;
+
+ while(1) { /* loop broken inside */
+ iRet = sun_openklog((LogName == NULL) ? PATH_LOG : LogName);
+ if(iRet == RS_RET_OK) {
+ if(tryNum > 1) {
+ errmsg.LogError(0, iRet, "failure on system log socket recovered.");
+ }
+ break;
+ }
+ /* failure, so sleep a bit. We wait try*10 ms, with a max of 15 seconds */
+ if(tryNum == 1) {
+ errmsg.LogError(0, iRet, "failure on system log socket, trying to recover...");
+ }
+ waitusecs = tryNum * 10000;
+ waitsecs = waitusecs / 1000000;
+ DBGPRINTF("imsolaris: try %d to recover system log socket in %d.%d seconds\n",
+ tryNum, waitsecs, waitusecs);
+ if(waitsecs > 15) {
+ waitsecs = 15;
+ waitusecs = 0;
+ } else {
+ waitusecs = waitusecs % 1000000;
+ }
+ srSleep(waitsecs, waitusecs);
+ ++tryNum;
+ }
+}
+
+
+/* This function receives data from a socket indicated to be ready
+ * to receive and submits the message received for processing.
+ * rgerhards, 2007-12-20
+ * Interface changed so that this function is passed the array index
+ * of the socket which is to be processed. This eases access to the
+ * growing number of properties. -- rgerhards, 2008-08-01
+ */
+static rsRetVal
+readLog(int fd, uchar *pRcv, int iMaxLine)
+{
+ DEFiRet;
+ struct strbuf data;
+ struct strbuf ctl;
+ struct log_ctl hdr;
+ int flags;
+ msg_t *pMsg;
+ int ret;
+ char errStr[1024];
+
+ data.buf = (char*)pRcv;
+ data.maxlen = iMaxLine;
+ ctl.maxlen = sizeof (struct log_ctl);
+ ctl.buf = (caddr_t)&hdr;
+ flags = 0;
+ ret = getmsg(fd, &ctl, &data, &flags);
+ if(ret < 0) {
+ if(errno == EINTR) {
+ FINALIZE;
+ } else {
+ int en = errno;
+ rs_strerror_r(errno, errStr, sizeof(errStr));
+ DBGPRINTF("imsolaris: stream input error on fd %d: %s.\n", fd, errStr);
+ errmsg.LogError(en, NO_ERRCODE, "imsolaris: stream input error: %s", errStr);
+ tryRecover();
+ }
+ } else {
+ DBGPRINTF("imsolaris: message from log stream %d: %s\n", fd, pRcv);
+ pRcv[data.len] = '\0'; /* make sure it is a valid C-String */
+ CHKiRet(msgConstruct(&pMsg));
+ MsgSetInputName(pMsg, pInputName);
+ MsgSetRawMsg(pMsg, (char*)pRcv, strlen((char*)pRcv));
+ MsgSetHOSTNAME(pMsg, glbl.GetLocalHostName(), ustrlen(glbl.GetLocalHostName()));
+ pMsg->iFacility = LOG_FAC(hdr.pri);
+ pMsg->iSeverity = LOG_PRI(hdr.pri);
+ pMsg->bParseHOSTNAME = 0;
+ pMsg->msgFlags = NEEDS_PARSING | NO_PRI_IN_RAW;
+ CHKiRet(submitMsg(pMsg));
+ }
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* once the system is fully initialized, we wait for new messages.
+ * We may think about replacing this with a read-loop, thus saving
+ * us the overhead of the poll.
+ * The timeout variable is the timeout to use for poll. During startup,
+ * it should be set to 0 (non-blocking) and later to -1 (infinit, blocking).
+ * This mimics the (strange) behaviour of the original syslogd.
+ * rgerhards, 2010-04-19
+ */
+static inline rsRetVal
+getMsgs(int timeout)
+{
+ DEFiRet;
+ int nfds;
+ int iMaxLine;
+ uchar *pRcv = NULL; /* receive buffer */
+ uchar bufRcv[4096+1];
+ char errStr[1024];
+
+ iMaxLine = glbl.GetMaxLine();
+
+ /* we optimize performance: if iMaxLine is below 4K (which it is in almost all
+ * cases, we use a fixed buffer on the stack. Only if it is higher, heap memory
+ * is used. We could use alloca() to achive a similar aspect, but there are so
+ * many issues with alloca() that I do not want to take that route.
+ * rgerhards, 2008-09-02
+ */
+ if((size_t) iMaxLine < sizeof(bufRcv) - 1) {
+ pRcv = bufRcv;
+ } else {
+ CHKmalloc(pRcv = (uchar*) malloc(sizeof(uchar) * (iMaxLine + 1)));
+ }
+
+ do {
+ DBGPRINTF("imsolaris: waiting for next message (timeout %d)...\n", timeout);
+ if(timeout == 0) {
+ nfds = poll(&sun_Pfd, 1, timeout); /* wait without timeout */
+
+ /* v5-TODO: here we must check if we should terminante! */
+
+ if(nfds == 0) {
+ if(timeout == 0) {
+ DBGPRINTF("imsolaris: no more messages, getMsgs() terminates\n");
+ FINALIZE;
+ } else {
+ continue;
+ }
+ }
+
+ if(nfds < 0) {
+ if(errno != EINTR) {
+ int en = errno;
+ rs_strerror_r(en, errStr, sizeof(errStr));
+ DBGPRINTF("imsolaris: poll error: %d = %s.\n", errno, errStr);
+ errmsg.LogError(en, NO_ERRCODE, "imsolaris: poll error: %s",
+ errStr);
+ }
+ continue;
+ }
+ if(sun_Pfd.revents & POLLIN) {
+ readLog(sun_Pfd.fd, pRcv, iMaxLine);
+ } else if(sun_Pfd.revents & (POLLNVAL|POLLHUP|POLLERR)) {
+ tryRecover();
+ }
+ } else {
+ /* if we have an infinite wait, we do not use poll at all
+ * I'd consider this a waste of time. However, I do not totally
+ * remove the code, as it may be useful if we decide at some
+ * point to provide a capability to support multiple input streams
+ * at once (this may be useful for a jail). In that case, the poll()
+ * loop would be needed, and so it doesn't make much sense to change
+ * the code to not support it. -- rgerhards, 2010-04-20
+ */
+ readLog(sun_Pfd.fd, pRcv, iMaxLine);
+ }
+
+ } while(1); /* TODO: in v5, we must check the termination predicate */
+
+ /* Note: in v4, this code is never reached (our thread will be cancelled) */
+
+finalize_it:
+ if(pRcv != NULL && (size_t) iMaxLine >= sizeof(bufRcv) - 1)
+ free(pRcv);
+
+ RETiRet;
+}
+
+
+/* This function is called to gather input. */
+BEGINrunInput
+CODESTARTrunInput
+ /* this is an endless loop - it is terminated when the thread is
+ * signalled to do so. This, however, is handled by the framework,
+ * right into the sleep below.
+ */
+
+ DBGPRINTF("imsolaris: doing startup poll before openeing door()\n");
+ CHKiRet(getMsgs(0));
+
+ /* note: sun's syslogd code claims that the door should only
+ * be opened when the log stream has been polled. So file header
+ * comment of this file for more details.
+ */
+ sun_open_door();
+ DBGPRINTF("imsolaris: starting regular poll loop\n");
+ iRet = getMsgs(-1); /* this is the primary poll loop, infinite timeout */
+
+finalize_it:
+ RETiRet;
+ENDrunInput
+
+
+BEGINwillRun
+CODESTARTwillRun
+ /* we need to create the inputName property (only once during our lifetime) */
+ CHKiRet(prop.Construct(&pInputName));
+ CHKiRet(prop.SetString(pInputName, UCHAR_CONSTANT("imsolaris"), sizeof("imsolaris") - 1));
+ CHKiRet(prop.ConstructFinalize(pInputName));
+
+ iRet = sun_openklog((LogName == NULL) ? PATH_LOG : LogName);
+ if(iRet != RS_RET_OK) {
+ errmsg.LogError(0, iRet, "error opening system log socket");
+ }
+finalize_it:
+ENDwillRun
+
+
+BEGINafterRun
+CODESTARTafterRun
+ /* do cleanup here */
+ if(pInputName != NULL)
+ prop.Destruct(&pInputName);
+ free(LogName);
+ENDafterRun
+
+
+BEGINmodExit
+CODESTARTmodExit
+ sun_delete_doorfiles();
+ objRelease(glbl, CORE_COMPONENT);
+ objRelease(errmsg, CORE_COMPONENT);
+ objRelease(prop, CORE_COMPONENT);
+ENDmodExit
+
+
+BEGINqueryEtryPt
+CODESTARTqueryEtryPt
+CODEqueryEtryPt_STD_IMOD_QUERIES
+ENDqueryEtryPt
+
+static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp,
+ void __attribute__((unused)) *pVal)
+{
+ return RS_RET_OK;
+}
+
+
+BEGINmodInit()
+CODESTARTmodInit
+ *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
+CODEmodInit_QueryRegCFSLineHdlr
+ CHKiRet(objUse(errmsg, CORE_COMPONENT));
+ CHKiRet(objUse(glbl, CORE_COMPONENT));
+ CHKiRet(objUse(prop, CORE_COMPONENT));
+
+ DBGPRINTF("imsolaris version %s initializing\n", PACKAGE_VERSION);
+
+ /* register config file handlers */
+ CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler,
+ resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID));
+ CHKiRet(omsdRegCFSLineHdlr((uchar *)"imsolarislogsocketname", 0, eCmdHdlrGetWord,
+ NULL, &LogName, STD_LOADABLE_MODULE_ID));
+ENDmodInit
+/* vim:set ai:
+ */