/* 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 program 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 2 * of the License, or (at your option) any later version. * * This program 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 this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * A copy of the GPL can be found in the file "COPYING" in this distribution. */ #include "config.h" #include "rsyslog.h" #include #include #include #include #include #include #include #include #include #include #include #include #if HAVE_FCNTL_H #include #else #include #endif #if HAVE_PATHS_H #include #endif #include "srUtils.h" #include "stringbuf.h" #include "syslogd-types.h" #include "syslogd.h" #include "omusrmsg.h" #include "module-template.h" /* internal structures */ DEF_OMOD_STATIC_DATA 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 BEGINneedUDPSocket CODESTARTneedUDPSocket ENDneedUDPSocket BEGINdbgPrintInstInfo register int i; CODESTARTdbgPrintInstInfo for (i = 0; i < MAXUNAMES && *pData->uname[i]; i++) printf("%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 BSD static FILE *BSD_uf = NULL; void setutent(void) { assert(BSD_uf == NULL); if ((BSD_uf = fopen(_PATH_UTMP, "r")) == NULL) { logerror(_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 /* * 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 * 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 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 BEGINonSelectReadyWrite CODESTARTonSelectReadyWrite ENDonSelectReadyWrite BEGINgetWriteFDForSelect CODESTARTgetWriteFDForSelect ENDgetWriteFDForSelect BEGINmodExit CODESTARTmodExit ENDmodExit BEGINqueryEtryPt CODESTARTqueryEtryPt CODEqueryEtryPt_STD_OMOD_QUERIES ENDqueryEtryPt BEGINmodInit(UsrMsg) CODESTARTmodInit *ipIFVersProvided = 1; /* so far, we only support the initial definition */ CODEmodInit_QueryRegCFSLineHdlr ENDmodInit /* * vi:set ai: */