~ubuntu-branches/ubuntu/lucid/rsyslog/lucid-updates

/* 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 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 <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 <setjmp.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

static jmp_buf ttybuf;

static void endtty()

{

	longjmp(ttybuf, 1);

}

/**

 * 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/".

 */

static rsRetVal wallmsg(uchar* pMsg, instanceData *pData)

{

	char p[sizeof(_PATH_DEV) + UNAMESZ];

	register int i;

	int ttyf;

	static int reenter = 0;

	struct utmp ut;

	struct utmp *uptr;

	struct sigaction sigAct;

	assert(pMsg != NULL);

	if (reenter++)

		return RS_RET_OK;

	/* open the user login file */

	setutent();

	/*

	 * Might as well fork instead of using nonblocking I/O

	 * and doing notty().

	 */

	if (fork() == 0) {

		memset(&sigAct, 0, sizeof(sigAct));

		sigemptyset(&sigAct.sa_mask);

		sigAct.sa_handler = SIG_DFL;

		sigaction(SIGTERM, &sigAct, NULL);

		alarm(0);

#		ifdef		SIGTTOU

		sigAct.sa_handler = SIG_DFL;

		sigaction(SIGTERM, &sigAct, NULL);

#		endif

		/* It is save to call sigprocmask here, as we are now executing the child (no threads) */

		sigprocmask(SIG_SETMASK, &sigAct.sa_mask, NULL);

	/* TODO: find a way to limit the max size of the message. hint: this

	 * should go into the template!

	 */

	/* rgerhards 2005-10-24: HINT: this code might be run in a seperate thread

	 * instead of a seperate process once we have multithreading...

	 */

		/* 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)

					continue;

			}

			/* compute the device name */

			strcpy(p, _PATH_DEV);

			strncat(p, ut.ut_line, UNAMESZ);

			if (setjmp(ttybuf) == 0) {

				sigAct.sa_handler = endtty;

				sigaction(SIGALRM, &sigAct, NULL);

				(void) alarm(15);

				/* open the terminal */

				ttyf = open(p, O_WRONLY|O_NOCTTY);

				if (ttyf >= 0) {

					struct stat statb;

					if (fstat(ttyf, &statb) == 0 &&

					    (statb.st_mode & S_IWRITE)) {

						(void) write(ttyf, pMsg, strlen((char*)pMsg));

					}

					close(ttyf);

					ttyf = -1;

				}

			}

			(void) alarm(0);

		}

		exit(0); /* "good" exit - this terminates the child forked just for message delivery */

	}

	/* close the user login file */

	endutent();

	reenter = 0;

	return RS_RET_OK;

}

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);

	if((iRet = createInstance(&pData)) != RS_RET_OK)

		goto finalize_it;

	if(*p == '*') { /* wall */

		dbgprintf("write-all");

		++p; /* eat '*' */

		pData->bIsWall = 1; /* write to all users */

		if((iRet = cflineParseTemplateName(&p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS, (uchar*) " WallFmt"))

		    != RS_RET_OK)

			goto finalize_it;

	} 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

/*

 * vi:set ai:

 */