/* omfwd.c * This is the implementation of the build-in forwarding output module. * * 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 . * * A copy of the GPL can be found in the file "COPYING" in this distribution. */ #include "config.h" #ifdef SYSLOG_INET #include "rsyslog.h" #include #include #include #include #include #include #include #include #include #include #include #include #ifdef USE_NETZIP #include #endif #include #include "syslogd.h" #include "syslogd-types.h" #include "srUtils.h" #include "net.h" #include "omfwd.h" #include "template.h" #include "msg.h" #include "tcpsyslog.h" #include "cfsysline.h" #include "module-template.h" MODULE_TYPE_OUTPUT #ifdef SYSLOG_INET #define INET_SUSPEND_TIME 60 /* equal to 1 minute * rgerhards, 2005-07-26: This was 3 minutes. As the * same timer is used for tcp based syslog, we have * reduced it. However, it might actually be worth * thinking about a buffered tcp sender, which would be * a much better alternative. When that happens, this * time here can be re-adjusted to 3 minutes (or, * even better, made configurable). */ #define INET_RETRY_MAX 30 /* maximum of retries for gethostbyname() */ /* was 10, changed to 30 because we reduced INET_SUSPEND_TIME by one third. So * this "fixes" some of implications of it (see comment on INET_SUSPEND_TIME). * rgerhards, 2005-07-26 */ #endif /* internal structures */ DEF_OMOD_STATIC_DATA typedef struct _instanceData { char f_hname[MAXHOSTNAMELEN+1]; short sock; /* file descriptor */ int *pSockArray; /* sockets to use for UDP */ enum { /* TODO: we shoud revisit these definitions */ eDestFORW, eDestFORW_SUSP, eDestFORW_UNKN } eDestState; int iRtryCnt; struct addrinfo *f_addr; int compressionLevel; /* 0 - no compression, else level for zlib */ char *port; int protocol; TCPFRAMINGMODE tcp_framing; # define FORW_UDP 0 # define FORW_TCP 1 /* following fields for TCP-based delivery */ time_t ttSuspend; /* time selector was suspended */ } instanceData; /* get the syslog forward port from selector_t. The passed in * struct must be one that is setup for forwarding. * rgerhards, 2007-06-28 * We may change the implementation to try to lookup the port * if it is unspecified. So far, we use the IANA default auf 514. */ char *getFwdSyslogPt(instanceData *pData) { assert(pData != NULL); if(pData->port == NULL) return("514"); else return(pData->port); } BEGINcreateInstance CODESTARTcreateInstance ENDcreateInstance BEGINisCompatibleWithFeature CODESTARTisCompatibleWithFeature if(eFeat == sFEATURERepeatedMsgReduction) iRet = RS_RET_OK; ENDisCompatibleWithFeature BEGINfreeInstance CODESTARTfreeInstance switch (pData->eDestState) { case eDestFORW: case eDestFORW_SUSP: freeaddrinfo(pData->f_addr); /* fall through */ case eDestFORW_UNKN: if(pData->port != NULL) free(pData->port); break; } /* final cleanup */ if(pData->sock >= 0) close(pData->sock); if(pData->pSockArray != NULL) closeUDPListenSockets(pData->pSockArray); ENDfreeInstance BEGINdbgPrintInstInfo CODESTARTdbgPrintInstInfo printf("%s", pData->f_hname); ENDdbgPrintInstInfo /* Send a message via UDP * rgehards, 2007-12-20 */ static rsRetVal UDPSend(instanceData *pData, char *msg, size_t len) { DEFiRet; struct addrinfo *r; int i; unsigned lsent = 0; int bSendSuccess; if(pData->pSockArray != NULL) { /* we need to track if we have success sending to the remote * peer. Success is indicated by at least one sendto() call * succeeding. We track this be bSendSuccess. We can not simply * rely on lsent, as a call might initially work, but a later * call fails. Then, lsent has the error status, even though * the sendto() succeeded. * rgerhards, 2007-06-22 */ bSendSuccess = FALSE; for (r = pData->f_addr; r; r = r->ai_next) { for (i = 0; i < *pData->pSockArray; i++) { lsent = sendto(pData->pSockArray[i+1], msg, len, 0, r->ai_addr, r->ai_addrlen); if (lsent == len) { bSendSuccess = TRUE; break; } else { int eno = errno; char errStr[1024]; dbgprintf("sendto() error: %d = %s.\n", eno, strerror_r(eno, errStr, sizeof(errStr))); } } if (lsent == len && !send_to_all) break; } /* finished looping */ if (bSendSuccess == FALSE) { dbgprintf("error forwarding via udp, suspending\n"); iRet = RS_RET_SUSPENDED; } } RETiRet; } /* CODE FOR SENDING TCP MESSAGES */ /* Send a frame via plain TCP protocol * rgerhards, 2007-12-28 */ static rsRetVal TCPSendFrame(void *pvData, char *msg, size_t len) { DEFiRet; ssize_t lenSend; instanceData *pData = (instanceData *) pvData; lenSend = send(pData->sock, msg, len, 0); dbgprintf("TCP sent %ld bytes, requested %ld\n", (long) lenSend, (long) len); if(lenSend == -1) { /* we have an error case - check what we can live with */ switch(errno) { case EMSGSIZE: dbgprintf("message not (tcp)send, too large\n"); /* This is not a real error, so it is not flagged as one */ break; default: dbgprintf("message not (tcp)send"); iRet = RS_RET_TCP_SEND_ERROR; break; } } else if(lenSend != (ssize_t) len) { /* no real error, could "just" not send everything... * For the time being, we ignore this... * rgerhards, 2005-10-25 */ dbgprintf("message not completely (tcp)send, ignoring %ld\n", lenSend); usleep(1000); /* experimental - might be benefitial in this situation */ /* TODO: we need to revisit this code -- rgerhards, 2007-12-28 */ } RETiRet; } /* This function is called immediately before a send retry is attempted. * It shall clean up whatever makes sense. * rgerhards, 2007-12-28 */ static rsRetVal TCPSendPrepRetry(void *pvData) { instanceData *pData = (instanceData *) pvData; assert(pData != NULL); close(pData->sock); pData->sock = -1; return RS_RET_OK; } /* initialies everything so that TCPSend can work. * rgerhards, 2007-12-28 */ static rsRetVal TCPSendInit(void *pvData) { DEFiRet; instanceData *pData = (instanceData *) pvData; assert(pData != NULL); if(pData->sock <= 0) { if((pData->sock = TCPSendCreateSocket(pData->f_addr)) <= 0) iRet = RS_RET_TCP_SOCKCREATE_ERR; } RETiRet; } /* try to resume connection if it is not ready * rgerhards, 2007-08-02 */ static rsRetVal doTryResume(instanceData *pData) { DEFiRet; struct addrinfo *res; struct addrinfo hints; unsigned e; switch (pData->eDestState) { case eDestFORW_SUSP: iRet = RS_RET_OK; /* the actual check happens during doAction() only */ pData->eDestState = eDestFORW; break; case eDestFORW_UNKN: /* The remote address is not yet known and needs to be obtained */ dbgprintf(" %s\n", pData->f_hname); memset(&hints, 0, sizeof(hints)); /* port must be numeric, because config file syntax requests this */ /* TODO: this code is a duplicate from cfline() - we should later create * a common function. */ hints.ai_flags = AI_NUMERICSERV; hints.ai_family = family; hints.ai_socktype = pData->protocol == FORW_UDP ? SOCK_DGRAM : SOCK_STREAM; if((e = getaddrinfo(pData->f_hname, getFwdSyslogPt(pData), &hints, &res)) == 0) { dbgprintf("%s found, resuming.\n", pData->f_hname); pData->f_addr = res; pData->iRtryCnt = 0; pData->eDestState = eDestFORW; } else { iRet = RS_RET_SUSPENDED; } break; case eDestFORW: /* rgerhards, 2007-09-11: this can not happen, but I've included it to * a) make the compiler happy, b) detect any logic errors */ assert(0); break; } RETiRet; } BEGINtryResume CODESTARTtryResume iRet = doTryResume(pData); ENDtryResume BEGINdoAction char *psz; /* temporary buffering */ register unsigned l; CODESTARTdoAction switch (pData->eDestState) { case eDestFORW_SUSP: dbgprintf("internal error in omfwd.c, eDestFORW_SUSP in doAction()!\n"); iRet = RS_RET_SUSPENDED; break; case eDestFORW_UNKN: dbgprintf("doAction eDestFORW_UNKN\n"); iRet = doTryResume(pData); break; case eDestFORW: dbgprintf(" %s:%s/%s\n", pData->f_hname, getFwdSyslogPt(pData), pData->protocol == FORW_UDP ? "udp" : "tcp"); /* with UDP, check if the socket is there and, if not, alloc * it. TODO: there should be a better place for that code. * rgerhards, 2007-12-26 */ if(pData->protocol == FORW_UDP) { if(pData->pSockArray == NULL) { pData->pSockArray = create_udp_socket((uchar*)pData->f_hname, NULL, 0); } } if ( 0) // TODO: think about this strcmp(getHOSTNAME(f->f_pMsg), LocalHostName) && NoHops ) /* what we need to do is get the hostname as an additonal string (during parseSe..). Then, * we can compare that string to LocalHostName. That way, we do not need to access the * msgobject, and everything is clean. The question remains, though, if that functionality * here actually makes sense or not. If we really need it, it might make more sense to compare * the target IP address to the IP addresses of the local machene - that is a far better way of * handling things than to relay on the error-prone hostname property. * rgerhards, 2007-07-27 */ dbgprintf("Not sending message to remote.\n"); else { pData->ttSuspend = time(NULL); psz = (char*) ppString[0]; l = strlen((char*) psz); if (l > MAXLINE) l = MAXLINE; # ifdef USE_NETZIP /* Check if we should compress and, if so, do it. We also * check if the message is large enough to justify compression. * The smaller the message, the less likely is a gain in compression. * To save CPU cycles, we do not try to compress very small messages. * What "very small" means needs to be configured. Currently, it is * hard-coded but this may be changed to a config parameter. * rgerhards, 2006-11-30 */ if(pData->compressionLevel && (l > MIN_SIZE_FOR_COMPRESS)) { Bytef out[MAXLINE+MAXLINE/100+12] = "z"; uLongf destLen = sizeof(out) / sizeof(Bytef); uLong srcLen = l; int ret; ret = compress2((Bytef*) out+1, &destLen, (Bytef*) psz, srcLen, pData->compressionLevel); dbgprintf("Compressing message, length was %d now %d, return state %d.\n", l, (int) destLen, ret); if(ret != Z_OK) { /* if we fail, we complain, but only in debug mode * Otherwise, we are silent. In any case, we ignore the * failed compression and just sent the uncompressed * data, which is still valid. So this is probably the * best course of action. * rgerhards, 2006-11-30 */ dbgprintf("Compression failed, sending uncompressed message\n"); } else if(destLen+1 < l) { /* only use compression if there is a gain in using it! */ dbgprintf("there is gain in compression, so we do it\n"); psz = (char*) out; l = destLen + 1; /* take care for the "z" at message start! */ } ++destLen; } # endif if(pData->protocol == FORW_UDP) { /* forward via UDP */ CHKiRet(UDPSend(pData, psz, l)); } else { /* forward via TCP */ rsRetVal ret; ret = TCPSend(pData, psz, l, pData->tcp_framing, TCPSendInit, TCPSendFrame, TCPSendPrepRetry); if(ret != RS_RET_OK) { /* error! */ dbgprintf("error forwarding via tcp, suspending\n"); pData->eDestState = eDestFORW_SUSP; iRet = RS_RET_SUSPENDED; } } } break; } finalize_it: ENDdoAction BEGINparseSelectorAct uchar *q; int i; int error; int bErr; struct addrinfo hints, *res; CODESTARTparseSelectorAct CODE_STD_STRING_REQUESTparseSelectorAct(1) if(*p == '@') { if((iRet = createInstance(&pData)) != RS_RET_OK) goto finalize_it; ++p; /* eat '@' */ if(*p == '@') { /* indicator for TCP! */ pData->protocol = FORW_TCP; ++p; /* eat this '@', too */ } else { pData->protocol = FORW_UDP; } /* we are now after the protocol indicator. Now check if we should * use compression. We begin to use a new option format for this: * @(option,option)host:port * The first option defined is "z[0..9]" where the digit indicates * the compression level. If it is not given, 9 (best compression) is * assumed. An example action statement might be: * @@(z5,o)127.0.0.1:1400 * Which means send via TCP with medium (5) compresion (z) to the local * host on port 1400. The '0' option means that octet-couting (as in * IETF I-D syslog-transport-tls) is to be used for framing (this option * applies to TCP-based syslog only and is ignored when specified with UDP). * That is not yet implemented. * rgerhards, 2006-12-07 */ if(*p == '(') { /* at this position, it *must* be an option indicator */ do { ++p; /* eat '(' or ',' (depending on when called) */ /* check options */ if(*p == 'z') { /* compression */ # ifdef USE_NETZIP ++p; /* eat */ if(isdigit((int) *p)) { int iLevel; iLevel = *p - '0'; ++p; /* eat */ pData->compressionLevel = iLevel; } else { logerrorInt("Invalid compression level '%c' specified in " "forwardig action - NOT turning on compression.", *p); } # else logerror("Compression requested, but rsyslogd is not compiled " "with compression support - request ignored."); # endif /* #ifdef USE_NETZIP */ } else if(*p == 'o') { /* octet-couting based TCP framing? */ ++p; /* eat */ /* no further options settable */ pData->tcp_framing = TCP_FRAMING_OCTET_COUNTING; } else { /* invalid option! Just skip it... */ logerrorInt("Invalid option %c in forwarding action - ignoring.", *p); ++p; /* eat invalid option */ } /* the option processing is done. We now do a generic skip * to either the next option or the end of the option * block. */ while(*p && *p != ')' && *p != ',') ++p; /* just skip it */ } while(*p && *p == ','); /* Attention: do.. while() */ if(*p == ')') ++p; /* eat terminator, on to next */ else /* we probably have end of string - leave it for the rest * of the code to handle it (but warn the user) */ logerror("Option block not terminated in forwarding action."); } /* extract the host first (we do a trick - we replace the ';' or ':' with a '\0') * now skip to port and then template name. rgerhards 2005-07-06 */ for(q = p ; *p && *p != ';' && *p != ':' ; ++p) /* JUST SKIP */; pData->port = NULL; if(*p == ':') { /* process port */ uchar * tmp; *p = '\0'; /* trick to obtain hostname (later)! */ tmp = ++p; for(i=0 ; *p && isdigit((int) *p) ; ++p, ++i) /* SKIP AND COUNT */; pData->port = malloc(i + 1); if(pData->port == NULL) { logerror("Could not get memory to store syslog forwarding port, " "using default port, results may not be what you intend\n"); /* we leave f_forw.port set to NULL, this is then handled by * getFwdSyslogPt(). */ } else { memcpy(pData->port, tmp, i); *(pData->port + i) = '\0'; } } /* now skip to template */ bErr = 0; while(*p && *p != ';') { if(*p && *p != ';' && !isspace((int) *p)) { if(bErr == 0) { /* only 1 error msg! */ bErr = 1; errno = 0; logerror("invalid selector line (port), probably not doing " "what was intended"); } } ++p; } /* TODO: make this if go away! */ if(*p == ';') { *p = '\0'; /* trick to obtain hostname (later)! */ strcpy(pData->f_hname, (char*) q); *p = ';'; } else strcpy(pData->f_hname, (char*) q); /* process template */ if((iRet = cflineParseTemplateName(&p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS, (uchar*) " StdFwdFmt")) != RS_RET_OK) goto finalize_it; /* first set the pData->eDestState */ memset(&hints, 0, sizeof(hints)); /* port must be numeric, because config file syntax requests this */ hints.ai_flags = AI_NUMERICSERV; hints.ai_family = family; hints.ai_socktype = pData->protocol == FORW_UDP ? SOCK_DGRAM : SOCK_STREAM; if( (error = getaddrinfo(pData->f_hname, getFwdSyslogPt(pData), &hints, &res)) != 0) { pData->eDestState = eDestFORW_UNKN; pData->iRtryCnt = INET_RETRY_MAX; pData->ttSuspend = time(NULL); } else { pData->eDestState = eDestFORW; pData->f_addr = res; } /* * Otherwise the host might be unknown due to an * inaccessible nameserver (perhaps on the same * host). We try to get the ip number later, like * FORW_SUSP. */ } else { iRet = RS_RET_CONFLINE_UNPROCESSED; } /* TODO: do we need to call freeInstance if we failed - this is a general question for * all output modules. I'll address it lates as the interface evolves. rgerhards, 2007-07-25 */ CODE_STD_FINALIZERparseSelectorAct ENDparseSelectorAct BEGINneedUDPSocket CODESTARTneedUDPSocket iRet = RS_RET_TRUE; ENDneedUDPSocket BEGINmodExit CODESTARTmodExit ENDmodExit BEGINqueryEtryPt CODESTARTqueryEtryPt CODEqueryEtryPt_STD_OMOD_QUERIES ENDqueryEtryPt BEGINmodInit(Fwd) CODESTARTmodInit *ipIFVersProvided = 1; /* so far, we only support the initial definition */ CODEmodInit_QueryRegCFSLineHdlr ENDmodInit #endif /* #ifdef SYSLOG_INET */ /* * vi:set ai: */