/* omfile.c * This is the implementation of the build-in file output module. * * Handles: F_CONSOLE, F_TTY, F_FILE, F_PIPE * * File begun on 2007-07-21 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 #include #include #include #include #include #include #include #include #include #include "rsyslog.h" #include "syslogd.h" #include "syslogd-types.h" #include "srUtils.h" #include "template.h" #include "outchannel.h" #include "omfile.h" /* query feature compatibility */ static rsRetVal isCompatibleWithFeature(syslogFeature eFeat) { if(eFeat == sFEATURERepeatedMsgReduction) return RS_RET_OK; return RS_RET_INCOMPATIBLE; } /* Helper to cfline(). Parses a output channel name up until the first * comma and then looks for the template specifier. Tries * to find that template. Maps the output channel to the * proper filed structure settings. Everything is stored in the * filed struct. Over time, the dependency on filed might be * removed. * rgerhards 2005-06-21 */ static rsRetVal cflineParseOutchannel(selector_t *f, uchar* p) { rsRetVal iRet = RS_RET_OK; size_t i; struct outchannel *pOch; char szBuf[128]; /* should be more than sufficient */ /* this must always be a file, because we can not set a size limit * on a pipe... * rgerhards 2005-06-21: later, this will be a separate type, but let's * emulate things for the time being. When everything runs, we can * extend it... */ f->f_type = F_FILE; ++p; /* skip '$' */ i = 0; /* get outchannel name */ while(*p && *p != ';' && *p != ' ' && i < sizeof(szBuf) / sizeof(char)) { szBuf[i++] = *p++; } szBuf[i] = '\0'; /* got the name, now look up the channel... */ pOch = ochFind(szBuf, i); if(pOch == NULL) { char errMsg[128]; errno = 0; snprintf(errMsg, sizeof(errMsg)/sizeof(char), "outchannel '%s' not found - ignoring action line", szBuf); logerror(errMsg); return RS_RET_NOT_FOUND; } /* check if there is a file name in the outchannel... */ if(pOch->pszFileTemplate == NULL) { char errMsg[128]; errno = 0; snprintf(errMsg, sizeof(errMsg)/sizeof(char), "outchannel '%s' has no file name template - ignoring action line", szBuf); logerror(errMsg); return RS_RET_ERR; } /* OK, we finally got a correct template. So let's use it... */ strncpy(f->f_un.f_file.f_fname, pOch->pszFileTemplate, MAXFNAME); f->f_un.f_file.f_sizeLimit = pOch->uSizeLimit; /* WARNING: It is dangerous "just" to pass the pointer. As we * never rebuild the output channel description, this is acceptable here. */ f->f_un.f_file.f_sizeLimitCmd = pOch->cmdOnSizeLimit; /* back to the input string - now let's look for the template to use * Just as a general precaution, we skip whitespace. */ while(*p && isspace((int) *p)) ++p; if(*p == ';') ++p; /* eat it */ if((iRet = cflineParseTemplateName(&p, szBuf, sizeof(szBuf) / sizeof(char))) == RS_RET_OK) { if(szBuf[0] == '\0') /* no template? */ strcpy(szBuf, " TradFmt"); /* use default! */ iRet = cflineSetTemplateAndIOV(f, szBuf); dprintf("[outchannel]filename: '%s', template: '%s', size: %lu\n", f->f_un.f_file.f_fname, szBuf, f->f_un.f_file.f_sizeLimit); } return(iRet); } /* rgerhards 2005-06-21: Try to resolve a size limit * situation. This first runs the command, and then * checks if we are still above the treshold. * returns 0 if ok, 1 otherwise * TODO: consider moving the initial check in here, too */ int resolveFileSizeLimit(selector_t *f) { uchar *pParams; uchar *pCmd; uchar *p; off_t actualFileSize; assert(f != NULL); if(f->f_un.f_file.f_sizeLimitCmd == NULL) return 1; /* nothing we can do in this case... */ /* the execProg() below is probably not great, but at least is is * fairly secure now. Once we change the way file size limits are * handled, we should also revisit how this command is run (and * with which parameters). rgerhards, 2007-07-20 */ /* we first check if we have command line parameters. We assume this, * when we have a space in the program name. If we find it, everything after * the space is treated as a single argument. */ if((pCmd = (uchar*)strdup((char*)f->f_un.f_file.f_sizeLimitCmd)) == NULL) { /* there is not much we can do - we make syslogd close the file in this case */ glblHadMemShortage = 1; return 1; } for(p = pCmd ; *p && *p != ' ' ; ++p) { /* JUST SKIP */ } if(*p == ' ') { *p = '\0'; /* pretend string-end */ pParams = p+1; } else pParams = NULL; execProg(pCmd, 1, pParams); f->f_file = open(f->f_un.f_file.f_fname, O_WRONLY|O_APPEND|O_CREAT|O_NOCTTY, f->f_un.f_file.fCreateMode); actualFileSize = lseek(f->f_file, 0, SEEK_END); if(actualFileSize >= f->f_un.f_file.f_sizeLimit) { /* OK, it didn't work out... */ return 1; } return 0; } /* This function deletes an entry from the dynamic file name * cache. A pointer to the cache must be passed in as well * as the index of the to-be-deleted entry. This index may * point to an unallocated entry, in whcih case the * function immediately returns. Parameter bFreeEntry is 1 * if the entry should be free()ed and 0 if not. */ static void dynaFileDelCacheEntry(dynaFileCacheEntry **pCache, int iEntry, int bFreeEntry) { assert(pCache != NULL); if(pCache[iEntry] == NULL) return; dprintf("Removed entry %d for file '%s' from dynaCache.\n", iEntry, pCache[iEntry]->pName == NULL ? "[OPEN FAILED]" : (char*)pCache[iEntry]->pName); /* if the name is NULL, this is an improperly initilized entry which * needs to be discarded. In this case, neither the file is to be closed * not the name to be freed. */ if(pCache[iEntry]->pName != NULL) { close(pCache[iEntry]->fd); free(pCache[iEntry]->pName); pCache[iEntry]->pName = NULL; } if(bFreeEntry) { free(pCache[iEntry]); pCache[iEntry] = NULL; } } /* This function frees the dynamic file name cache. */ static void dynaFileFreeCache(selector_t *f) { register int i; assert(f != NULL); for(i = 0 ; i < f->f_un.f_file.iCurrCacheSize ; ++i) { dynaFileDelCacheEntry(f->f_un.f_file.dynCache, i, 1); } free(f->f_un.f_file.dynCache); } /* This function handles dynamic file names. It generates a new one * based on the current message, checks if that file is already open * and, if not, does everything needed to switch to the new one. * Function returns 0 if all went well and non-zero otherwise. * On successful return f->f_file must point to the correct file to * be written. * This is a helper to writeFile(). rgerhards, 2007-07-03 */ static int prepareDynFile(selector_t *f) { uchar *newFileName; time_t ttOldest; /* timestamp of oldest element */ int iOldest; int i; int iFirstFree; dynaFileCacheEntry **pCache; assert(f != NULL); if((newFileName = tplToString(f->f_un.f_file.pTpl, f->f_pMsg)) == NULL) { /* memory shortage - there is nothing we can do to resolve it. * We silently ignore it, this is probably the best we can do. */ glblHadMemShortage = TRUE; dprintf("prepareDynfile(): could not create file name, discarding this request\n"); return -1; } pCache = f->f_un.f_file.dynCache; /* first check, if we still have the current file * I *hope* this will be a performance enhancement. */ if( (f->f_un.f_file.iCurrElt != -1) && !strcmp((char*) newFileName, (char*) pCache[f->f_un.f_file.iCurrElt])) { /* great, we are all set */ free(newFileName); pCache[f->f_un.f_file.iCurrElt]->lastUsed = time(NULL); /* update timestamp for LRU */ return 0; } /* ok, no luck. Now let's search the table if we find a matching spot. * While doing so, we also prepare for creation of a new one. */ iFirstFree = -1; /* not yet found */ iOldest = 0; /* we assume the first element to be the oldest - that will change as we loop */ ttOldest = time(NULL) + 1; /* there must always be an older one */ for(i = 0 ; i < f->f_un.f_file.iCurrCacheSize ; ++i) { if(pCache[i] == NULL) { if(iFirstFree == -1) iFirstFree = i; } else { /* got an element, let's see if it matches */ if(!strcmp((char*) newFileName, (char*) pCache[i]->pName)) { /* we found our element! */ f->f_file = pCache[i]->fd; f->f_un.f_file.iCurrElt = i; free(newFileName); pCache[i]->lastUsed = time(NULL); /* update timestamp for LRU */ return 0; } /* did not find it - so lets keep track of the counters for LRU */ if(pCache[i]->lastUsed < ttOldest) { ttOldest = pCache[i]->lastUsed; iOldest = i; } } } /* we have not found an entry */ if(iFirstFree == -1 && (f->f_un.f_file.iCurrCacheSize < f->f_un.f_file.iDynaFileCacheSize)) { /* there is space left, so set it to that index */ iFirstFree = f->f_un.f_file.iCurrCacheSize++; } if(iFirstFree == -1) { dynaFileDelCacheEntry(pCache, iOldest, 0); iFirstFree = iOldest; /* this one *is* now free ;) */ } else { /* we need to allocate memory for the cache structure */ pCache[iFirstFree] = (dynaFileCacheEntry*) calloc(1, sizeof(dynaFileCacheEntry)); if(pCache[iFirstFree] == NULL) { glblHadMemShortage = TRUE; dprintf("prepareDynfile(): could not alloc mem, discarding this request\n"); free(newFileName); return -1; } } /* Ok, we finally can open the file */ if(access((char*)newFileName, F_OK) == 0) { /* file already exists */ f->f_file = open((char*) newFileName, O_WRONLY|O_APPEND|O_CREAT|O_NOCTTY, f->f_un.f_file.fCreateMode); } else { /* file does not exist, create it (and eventually parent directories */ if(f->f_un.f_file.bCreateDirs) { /* we fist need to create parent dirs if they are missing * We do not report any errors here ourselfs but let the code * fall through to error handler below. */ if(makeFileParentDirs(newFileName, strlen((char*)newFileName), f->f_un.f_file.fDirCreateMode, f->f_un.f_file.dirUID, f->f_un.f_file.dirGID, f->f_un.f_file.bFailOnChown) == 0) { f->f_file = open((char*) newFileName, O_WRONLY|O_APPEND|O_CREAT|O_NOCTTY, f->f_un.f_file.fCreateMode); if(f->f_file != -1) { /* check and set uid/gid */ if(f->f_un.f_file.fileUID != (uid_t)-1 || f->f_un.f_file.fileGID != (gid_t) -1) { /* we need to set owner/group */ if(fchown(f->f_file, f->f_un.f_file.fileUID, f->f_un.f_file.fileGID) != 0) { if(f->f_un.f_file.bFailOnChown) { int eSave = errno; close(f->f_file); f->f_file = -1; errno = eSave; } /* we will silently ignore the chown() failure * if configured to do so. */ } } } } } } /* file is either open now or an error state set */ if(f->f_file == -1) { /* do not report anything if the message is an internally-generated * message. Otherwise, we could run into a never-ending loop. The bad * news is that we also lose errors on startup messages, but so it is. */ if(f->f_pMsg->msgFlags & INTERNAL_MSG) dprintf("Could not open dynaFile, discarding message\n"); else logerrorSz("Could not open dynamic file '%s' - discarding message", (char*)newFileName); free(newFileName); dynaFileDelCacheEntry(pCache, iFirstFree, 1); return -1; } pCache[iFirstFree]->fd = f->f_file; pCache[iFirstFree]->pName = newFileName; pCache[iFirstFree]->lastUsed = time(NULL); f->f_un.f_file.iCurrElt = iFirstFree; dprintf("Added new entry %d for file cache, file '%s'.\n", iFirstFree, newFileName); return 0; } /* rgerhards 2004-11-11: write to a file output. This * will be called for all outputs using file semantics, * for example also for pipes. */ static rsRetVal writeFile(selector_t *f) { off_t actualFileSize; rsRetVal iRet = RS_RET_OK; assert(f != NULL); /* first check if we have a dynamic file name and, if so, * check if it still is ok or a new file needs to be created */ if(f->f_un.f_file.bDynamicName) { if(prepareDynFile(f) != 0) return RS_RET_ERR; } /* create the message based on format specified */ iovCreate(f); again: /* check if we have a file size limit and, if so, * obey to it. */ if(f->f_un.f_file.f_sizeLimit != 0) { actualFileSize = lseek(f->f_file, 0, SEEK_END); if(actualFileSize >= f->f_un.f_file.f_sizeLimit) { char errMsg[256]; /* for now, we simply disable a file once it is * beyond the maximum size. This is better than having * us aborted by the OS... rgerhards 2005-06-21 */ (void) close(f->f_file); /* try to resolve the situation */ if(resolveFileSizeLimit(f) != 0) { /* didn't work out, so disable... */ snprintf(errMsg, sizeof(errMsg), "no longer writing to file %s; grown beyond configured file size of %lld bytes, actual size %lld - configured command did not resolve situation", f->f_un.f_file.f_fname, (long long) f->f_un.f_file.f_sizeLimit, (long long) actualFileSize); errno = 0; logerror(errMsg); return RS_RET_DISABLE_ACTION; } else { snprintf(errMsg, sizeof(errMsg), "file %s had grown beyond configured file size of %lld bytes, actual size was %lld - configured command resolved situation", f->f_un.f_file.f_fname, (long long) f->f_un.f_file.f_sizeLimit, (long long) actualFileSize); errno = 0; logerror(errMsg); } } } if (writev(f->f_file, f->f_iov, f->f_iIovUsed) < 0) { int e = errno; /* If a named pipe is full, just ignore it for now - mrn 24 May 96 */ if (f->f_type == F_PIPE && e == EAGAIN) return RS_RET_OK; /* If the filesystem is filled up, just ignore * it for now and continue writing when possible * based on patch for sysklogd by Martin Schulze on 2007-05-24 */ if (f->f_type == F_FILE && e == ENOSPC) return RS_RET_OK; (void) close(f->f_file); /* * Check for EBADF on TTY's due to vhangup() * Linux uses EIO instead (mrn 12 May 96) */ if ((f->f_type == F_TTY || f->f_type == F_CONSOLE) #ifdef linux && e == EIO) { #else && e == EBADF) { #endif f->f_file = open(f->f_un.f_file.f_fname, O_WRONLY|O_APPEND|O_NOCTTY); if (f->f_file < 0) { iRet = RS_RET_DISABLE_ACTION; logerror(f->f_un.f_file.f_fname); } else { untty(); goto again; } } else { iRet = RS_RET_DISABLE_ACTION; errno = e; logerror(f->f_un.f_file.f_fname); } } else if (f->f_flags & SYNC_FILE) fsync(f->f_file); return(iRet); } /* free an instance */ static rsRetVal freeInstance(selector_t *f) { assert(f != NULL); if(f->f_un.f_file.bDynamicName) { dynaFileFreeCache(f); } else close(f->f_file); return RS_RET_OK; } /* call the shell action */ static rsRetVal doActionFile(selector_t *f) { assert(f != NULL); rsRetVal iRet = RS_RET_OK; dprintf(" (%s)\n", f->f_un.f_file.f_fname); /* f->f_file == -1 is an indicator that the we couldn't * open the file at startup. For dynaFiles, this is ok, * all others are doomed. */ if(f->f_un.f_file.bDynamicName || (f->f_file != -1)) iRet = writeFile(f); return iRet; } /* try to process a selector action line. Checks if the action * applies to this module and, if so, processed it. If not, it * is left untouched. The driver will then call another module */ static rsRetVal parseSelectorAct(uchar **pp, selector_t *f) { uchar *p; int syncfile; rsRetVal iRet = RS_RET_CONFLINE_PROCESSED; assert(pp != NULL); assert(f != NULL); p = *pp; if (*p == '-') { syncfile = 0; p++; } else syncfile = 1; switch (*p) { case '$': /* rgerhards 2005-06-21: this is a special setting for output-channel * definitions. In the long term, this setting will probably replace * anything else, but for the time being we must co-exist with the * traditional mode lines. * rgerhards, 2007-07-24: output-channels will go away. We keep them * for compatibility reasons, but seems to have been a bad idea. */ if((iRet = cflineParseOutchannel(f, p)) == RS_RET_OK) { f->f_un.f_file.bDynamicName = 0; f->f_un.f_file.fCreateMode = fCreateMode; /* preserve current setting */ f->f_un.f_file.fDirCreateMode = fDirCreateMode; /* preserve current setting */ f->f_file = open(f->f_un.f_file.f_fname, O_WRONLY|O_APPEND|O_CREAT|O_NOCTTY, f->f_un.f_file.fCreateMode); } break; case '?': /* This is much like a regular file handle, but we need to obtain * a template name. rgerhards, 2007-07-03 */ ++p; /* eat '?' */ if((iRet = cflineParseFileName(f, p)) != RS_RET_OK) break; f->f_un.f_file.pTpl = tplFind((char*)f->f_un.f_file.f_fname, strlen((char*) f->f_un.f_file.f_fname)); if(f->f_un.f_file.pTpl == NULL) { logerrorSz("Template '%s' not found - dynaFile deactivated.", f->f_un.f_file.f_fname); iRet = RS_RET_NOT_FOUND; /* that's it... :( */ break; } if(syncfile) f->f_flags |= SYNC_FILE; f->f_un.f_file.bDynamicName = 1; f->f_un.f_file.iCurrElt = -1; /* no current element */ f->f_un.f_file.fCreateMode = fCreateMode; /* freeze current setting */ f->f_un.f_file.fDirCreateMode = fDirCreateMode; /* preserve current setting */ f->f_un.f_file.bCreateDirs = bCreateDirs; f->f_un.f_file.bFailOnChown = bFailOnChown; f->f_un.f_file.fileUID = fileUID; f->f_un.f_file.fileGID = fileGID; f->f_un.f_file.dirUID = dirUID; f->f_un.f_file.dirGID = dirGID; f->f_un.f_file.iDynaFileCacheSize = iDynaFileCacheSize; /* freeze current setting */ /* we now allocate the cache table. We use calloc() intentionally, as we * need all pointers to be initialized to NULL pointers. */ if((f->f_un.f_file.dynCache = (dynaFileCacheEntry**) calloc(iDynaFileCacheSize, sizeof(dynaFileCacheEntry*))) == NULL) { iRet = RS_RET_OUT_OF_MEMORY; dprintf("Could not allocate memory for dynaFileCache - selector disabled.\n"); } break; case '|': case '/': /* rgerhards 2004-11-17: from now, we need to have different * processing, because after the first comma, the template name * to use is specified. So we need to scan for the first coma first * and then look at the rest of the line. */ if((iRet = cflineParseFileName(f, p)) != RS_RET_OK) break; if(syncfile) f->f_flags |= SYNC_FILE; f->f_un.f_file.bDynamicName = 0; f->f_un.f_file.fCreateMode = fCreateMode; /* preserve current setting */ if(f->f_type == F_PIPE) { f->f_file = open(f->f_un.f_file.f_fname, O_RDWR|O_NONBLOCK); } else { f->f_file = open(f->f_un.f_file.f_fname, O_WRONLY|O_APPEND|O_CREAT|O_NOCTTY, f->f_un.f_file.fCreateMode); } if ( f->f_file < 0 ){ f->f_file = -1; dprintf("Error opening log file: %s\n", f->f_un.f_file.f_fname); logerror(f->f_un.f_file.f_fname); break; } if (isatty(f->f_file)) { f->f_type = F_TTY; untty(); } if (strcmp((char*) p, ctty) == 0) f->f_type = F_CONSOLE; break; default: iRet = RS_RET_CONFLINE_UNPROCESSED; break; } if(iRet == RS_RET_OK) iRet = RS_RET_CONFLINE_PROCESSED; if(iRet == RS_RET_CONFLINE_PROCESSED) *pp = p; return iRet; } /* query an entry point */ static rsRetVal queryEtryPt(uchar *name, rsRetVal (**pEtryPoint)()) { if((name == NULL) || (pEtryPoint == NULL)) return RS_RET_PARAM_ERROR; *pEtryPoint = NULL; if(!strcmp((char*) name, "doAction")) { *pEtryPoint = doActionFile; } else if(!strcmp((char*) name, "parseSelectorAct")) { *pEtryPoint = parseSelectorAct; } else if(!strcmp((char*) name, "isCompatibleWithFeature")) { *pEtryPoint = isCompatibleWithFeature; } else if(!strcmp((char*) name, "freeInstance")) { *pEtryPoint = freeInstance; } return(*pEtryPoint == NULL) ? RS_RET_NOT_FOUND : RS_RET_OK; } /* initialize the module * * Later, much more must be done. So far, we only return a pointer * to the queryEtryPt() function * TODO: do interface version checking & handshaking * iIfVersRequeted is the version of the interface specification that the * caller would like to see being used. ipIFVersProvided is what we * decide to provide. */ rsRetVal modInitFile(int iIFVersRequested __attribute__((unused)), int *ipIFVersProvided, rsRetVal (**pQueryEtryPt)()) { if((pQueryEtryPt == NULL) || (ipIFVersProvided == NULL)) return RS_RET_PARAM_ERROR; *ipIFVersProvided = 1; /* so far, we only support the initial definition */ *pQueryEtryPt = queryEtryPt; return RS_RET_OK; } /* * vi:set ai: */