1 files changed, 326 insertions, 0 deletions
diff --git a/tools/omusrmsg.c b/tools/omusrmsg.c
new file mode 100644
index 0000000..830bbc8
--- /dev/null
+++ b/tools/omusrmsg.c
@@ -0,0 +1,326 @@
+/* omusrmsg.c
+ * This is the implementation of the build-in output module for sending
+ * user messages.
+ *
+ * NOTE: read comments in module-template.h to understand how this file
+ *       works!
+ *
+ * File begun on 2007-07-20 by RGerhards (extracted from syslogd.c)
+ * This file is under development and has not yet arrived at being fully
+ * self-contained and a real object. So far, it is mostly an excerpt
+ * of the "old" message code without any modifications. However, it
+ * helps to have things at the right place one we go to the meat of it.
+ *
+ * Copyright 2007, 2008 Rainer Gerhards and Adiscon GmbH.
+ *
+ * rgerhards, 2008-07-04 (happy Independence Day!): rsyslog inherited the
+ * wall functionality from sysklogd. Sysklogd was single-threaded and could
+ * not afford to spent a lot of time inside a single action. Thus, it forked
+ * off a new process to do the wall. In rsyslog, however, this creates some
+ * grief with the threading model. Also, we do not really need to de-couple
+ * processing, because we have ample ways to do it in rsyslog. Plus, the
+ * default main message queue will care for a somewhat longer execution time.
+ * So in short, the real fix to the problem is an architecture change. From
+ * now on, we will not fork off a new process but rather do the notification
+ * within the current one. This also reduces system overhead.
+ *
+ * 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 <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <signal.h>
+#include <sys/param.h>
+#include <utmp.h>
+#include <unistd.h>
+#include <sys/uio.h>
+#include <sys/stat.h>
+#include <errno.h>
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#else
+#include <sys/msgbuf.h>
+#endif
+#if HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include "srUtils.h"
+#include "stringbuf.h"
+#include "syslogd-types.h"
+#include "syslogd.h"
+#include "omusrmsg.h"
+#include "module-template.h"
+#include "errmsg.h"
+
+
+/* portability: */
+#ifndef _PATH_DEV
+#	define _PATH_DEV	"/dev/"
+#endif
+
+
+MODULE_TYPE_OUTPUT
+
+/* internal structures
+ */
+DEF_OMOD_STATIC_DATA
+DEFobjCurrIf(errmsg)
+
+typedef struct _instanceData {
+	int bIsWall; /* 1- is wall, 0 - individual users */
+	char uname[MAXUNAMES][UNAMESZ+1];
+} instanceData;
+
+
+BEGINcreateInstance
+CODESTARTcreateInstance
+ENDcreateInstance
+
+
+BEGINisCompatibleWithFeature
+CODESTARTisCompatibleWithFeature
+	if(eFeat == sFEATURERepeatedMsgReduction)
+		iRet = RS_RET_OK;
+ENDisCompatibleWithFeature
+
+
+BEGINfreeInstance
+CODESTARTfreeInstance
+	/* TODO: free the instance pointer (currently a leak, will go away) */
+ENDfreeInstance
+
+
+BEGINdbgPrintInstInfo
+	register int i;
+CODESTARTdbgPrintInstInfo
+	for (i = 0; i < MAXUNAMES && *pData->uname[i]; i++)
+		dbgprintf("%s, ", pData->uname[i]);
+ENDdbgPrintInstInfo
+
+
+/**
+ * BSD setutent/getutent() replacement routines
+ * The following routines emulate setutent() and getutent() under
+ * BSD because they are not available there. We only emulate what we actually
+ * need! rgerhards 2005-03-18
+ */
+#ifdef OS_BSD
+static FILE *BSD_uf = NULL;
+void setutent(void)
+{
+	assert(BSD_uf == NULL);
+	if ((BSD_uf = fopen(_PATH_UTMP, "r")) == NULL) {
+		errmsg.LogError(NO_ERRCODE, "%s", _PATH_UTMP);
+		return;
+	}
+}
+
+struct utmp* getutent(void)
+{
+	static struct utmp st_utmp;
+
+	if(fread((char *)&st_utmp, sizeof(st_utmp), 1, BSD_uf) != 1)
+		return NULL;
+
+	return(&st_utmp);
+}
+
+void endutent(void)
+{
+	fclose(BSD_uf);
+	BSD_uf = NULL;
+}
+#endif  /* #ifdef OS_BSD */
+
+
+/*  WALLMSG -- Write a message to the world at large
+ *
+ *	Write the specified message to either the entire
+ *	world, or a list of approved users.
+ *
+ * rgerhards, 2005-10-19: applying the following sysklogd patch:
+ * Tue May  4 16:52:01 CEST 2004: Solar Designer <solar@openwall.com>
+ *	Adjust the size of a variable to prevent a buffer overflow
+ *	should _PATH_DEV ever contain something different than "/dev/".
+ * rgerhards, 2008-07-04: changing the function to no longer use fork() but
+ * 	continue run on its thread instead.
+ */
+static rsRetVal wallmsg(uchar* pMsg, instanceData *pData)
+{
+  
+	uchar szErr[512];
+	char p[sizeof(_PATH_DEV) + UNAMESZ];
+	register int i;
+	int errnoSave;
+	int ttyf;
+	int wrRet;
+	struct utmp ut;
+	struct utmp *uptr;
+	struct stat statb;
+	DEFiRet;
+
+	assert(pMsg != NULL);
+
+	/* open the user login file */
+	setutent();
+
+	/* scan the user login file */
+	while((uptr = getutent())) {
+		memcpy(&ut, uptr, sizeof(ut));
+		/* is this slot used? */
+		if(ut.ut_name[0] == '\0')
+			continue;
+#ifndef OS_BSD
+		if(ut.ut_type != USER_PROCESS)
+			continue;
+#endif
+		if(!(strncmp (ut.ut_name,"LOGIN", 6))) /* paranoia */
+			continue;
+
+		/* should we send the message to this user? */
+		if(pData->bIsWall == 0) {
+			for(i = 0; i < MAXUNAMES; i++) {
+				if(!pData->uname[i][0]) {
+					i = MAXUNAMES;
+					break;
+				}
+				if(strncmp(pData->uname[i], ut.ut_name, UNAMESZ) == 0)
+					break;
+			}
+			if(i == MAXUNAMES) /* user not found? */
+				continue; /* on to next user! */
+		}
+
+		/* compute the device name */
+		strcpy(p, _PATH_DEV);
+		strncat(p, ut.ut_line, UNAMESZ);
+
+		/* we must be careful when writing to the terminal. A terminal may block
+		 * (for example, a user has pressed <ctl>-s). In that case, we can not
+		 * wait indefinitely. So we need to use non-blocking I/O. In case we would
+		 * block, we simply do not send the message, because that's the best we can
+		 * do. -- rgerhards, 2008-07-04
+		 */
+
+		/* open the terminal */
+		if((ttyf = open(p, O_WRONLY|O_NOCTTY|O_NONBLOCK)) >= 0) {
+			if(fstat(ttyf, &statb) == 0 && (statb.st_mode & S_IWRITE)) {
+				wrRet = write(ttyf, pMsg, strlen((char*)pMsg));
+				if(Debug && wrRet == -1) {
+					/* we record the state to the debug log */
+					errnoSave = errno;
+					rs_strerror_r(errno, (char*)szErr, sizeof(szErr));
+					dbgprintf("write to terminal '%s' failed with [%d]:%s\n",
+						  p, errnoSave, szErr);
+				}
+			}
+			close(ttyf);
+			ttyf = -1;
+		}
+	}
+
+	/* close the user login file */
+	endutent();
+	RETiRet;
+}
+
+
+BEGINtryResume
+CODESTARTtryResume
+ENDtryResume
+
+BEGINdoAction
+CODESTARTdoAction
+	dbgprintf("\n");
+	iRet = wallmsg(ppString[0], pData);
+ENDdoAction
+
+
+BEGINparseSelectorAct
+	uchar *q;
+	int i;
+CODESTARTparseSelectorAct
+CODE_STD_STRING_REQUESTparseSelectorAct(1)
+	   /* User names must begin with a gnu e-regex:
+	    *   [a-zA-Z0-9_.]
+	    * plus '*' for wall
+	    */
+	if(!*p || !((*p >= 'a' && *p <= 'z') || (*p >= 'A' && *p <= 'Z')
+	   || (*p >= '0' && *p <= '9') || *p == '_' || *p == '.' || *p == '*'))
+		ABORT_FINALIZE(RS_RET_CONFLINE_UNPROCESSED);
+
+	CHKiRet(createInstance(&pData));
+
+	if(*p == '*') { /* wall */
+		dbgprintf("write-all");
+		++p; /* eat '*' */
+		pData->bIsWall = 1; /* write to all users */
+		CHKiRet(cflineParseTemplateName(&p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS, (uchar*) " WallFmt"));
+	} else {
+		/* everything else beginning with the regex above
+		 * is currently treated as a user name -- TODO: is this portable?
+		 */
+		dbgprintf("users: %s\n", p);	/* ASP */
+		pData->bIsWall = 0; /* write to individual users */
+		for (i = 0; i < MAXUNAMES && *p && *p != ';'; i++) {
+			for (q = p; *q && *q != ',' && *q != ';'; )
+				q++;
+			(void) strncpy((char*) pData->uname[i], (char*) p, UNAMESZ);
+			if ((q - p) > UNAMESZ)
+				pData->uname[i][UNAMESZ] = '\0';
+			else
+				pData->uname[i][q - p] = '\0';
+			while (*q == ',' || *q == ' ')
+				q++;
+			p = q;
+		}
+		/* done, on to the template
+		 * TODO: we need to handle the case where i >= MAXUNAME!
+		 */
+		if((iRet = cflineParseTemplateName(&p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS, (uchar*)" StdUsrMsgFmt"))
+			!= RS_RET_OK)
+			goto finalize_it;
+	}
+CODE_STD_FINALIZERparseSelectorAct
+ENDparseSelectorAct
+
+
+BEGINmodExit
+CODESTARTmodExit
+ENDmodExit
+
+
+BEGINqueryEtryPt
+CODESTARTqueryEtryPt
+CODEqueryEtryPt_STD_OMOD_QUERIES
+ENDqueryEtryPt
+
+
+BEGINmodInit(UsrMsg)
+CODESTARTmodInit
+	*ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
+CODEmodInit_QueryRegCFSLineHdlr
+	CHKiRet(objUse(errmsg, CORE_COMPONENT));
+ENDmodInit
+
+/* vim:set ai:
+ */