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author | Rainer Gerhards <rgerhards@adiscon.com> | 2008-03-12 14:08:21 +0000 |
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committer | Rainer Gerhards <rgerhards@adiscon.com> | 2008-03-12 14:08:21 +0000 |
commit | 618a7f6a220563a50909d0e15eb90ce222aced31 (patch) | |
tree | 484439581a66494bbed91aa6e53f4b571126e820 /tcpsyslog.c | |
parent | 9ddee5b38772f42f4371c6828a832f0d6267251d (diff) | |
download | rsyslog-618a7f6a220563a50909d0e15eb90ce222aced31.tar.gz rsyslog-618a7f6a220563a50909d0e15eb90ce222aced31.tar.xz rsyslog-618a7f6a220563a50909d0e15eb90ce222aced31.zip |
changed omgssapi and omfwd to utilize new object calling interface; made a
tcpclt class; (stage work, among others, for more intelligent recovery
from TCP session recovery)
Diffstat (limited to 'tcpsyslog.c')
-rw-r--r-- | tcpsyslog.c | 284 |
1 files changed, 3 insertions, 281 deletions
diff --git a/tcpsyslog.c b/tcpsyslog.c index b521eac2..d00731d3 100644 --- a/tcpsyslog.c +++ b/tcpsyslog.c @@ -1,5 +1,6 @@ /* tcpsyslog.c - * This is the implementation of TCP-based syslog. + * This is the implementation of TCP-based syslog. It includes those + * (few) things that both clients and servers need. * * 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 @@ -49,285 +50,6 @@ #include "tcpsyslog.h" #include "srUtils.h" -#ifdef SYSLOG_INET -/* ----------------------------------------------------------------- * - * CODE THAT SHALL GO INTO ITS OWN MODULE (SENDING) * - * ----------------------------------------------------------------- */ - -/* Initialize TCP sockets (for sender) - * This is done once per selector line, if not yet initialized. - */ -int TCPSendCreateSocket(struct addrinfo *addrDest) -{ - int fd; - struct addrinfo *r; - - r = addrDest; - - while(r != NULL) { - fd = socket(r->ai_family, r->ai_socktype, r->ai_protocol); - if (fd != -1) { - /* We can not allow the TCP sender to block syslogd, at least - * not in a single-threaded design. That would cause rsyslogd to - * loose input messages - which obviously also would affect - * other selector lines, too. So we do set it to non-blocking and - * handle the situation ourselfs (by discarding messages). IF we run - * dual-threaded, however, the situation is different: in this case, - * the receivers and the selector line processing are only loosely - * coupled via a memory buffer. Now, I think, we can afford the extra - * wait time. Thus, we enable blocking mode for TCP if we compile with - * pthreads. -- rgerhards, 2005-10-25 - * And now, we always run on multiple threads... -- rgerhards, 2007-12-20 - */ - if (connect (fd, r->ai_addr, r->ai_addrlen) != 0) { - if(errno == EINPROGRESS) { - /* this is normal - will complete later select */ - return fd; - } else { - char errStr[1024]; - dbgprintf("create tcp connection failed, reason %s", - rs_strerror_r(errno, errStr, sizeof(errStr))); - } - - } - else { - return fd; - } - close(fd); - } - else { - char errStr[1024]; - dbgprintf("couldn't create send socket, reason %s", rs_strerror_r(errno, errStr, sizeof(errStr))); - } - r = r->ai_next; - } - - dbgprintf("no working socket could be obtained"); - - return -1; -} - - - -/* Build frame based on selected framing - * This function was created by pulling code from TCPSend() - * on 2007-12-27 by rgerhards. Older comments are still relevant. - * - * In order to support compressed messages via TCP, we must support an - * octet-counting based framing (LF may be part of the compressed message). - * We are now supporting the same mode that is available in IETF I-D - * syslog-transport-tls-05 (current at the time of this writing). This also - * eases things when we go ahead and implement that framing. I have now made - * available two cases where this framing is used: either by explitely - * specifying it in the config file or implicitely when sending a compressed - * message. In the later case, compressed and uncompressed messages within - * the same session have different framings. If it is explicitely set to - * octet-counting, only this framing mode is used within the session. - * rgerhards, 2006-12-07 - */ -static rsRetVal TCPSendBldFrame(TCPFRAMINGMODE rqdFraming, char **pmsg, size_t *plen, int *pbMustBeFreed) -{ - DEFiRet; - TCPFRAMINGMODE framingToUse; - int bIsCompressed; - size_t len; - char *msg; - char *buf = NULL; /* if this is non-NULL, it MUST be freed before return! */ - - assert(plen != NULL); - assert(pbMustBeFreed != NULL); - assert(pmsg != NULL); - - msg = *pmsg; - len = *plen; - bIsCompressed = *msg == 'z'; /* cache this, so that we can modify the message buffer */ - /* select framing for this record. If we have a compressed record, we always need to - * use octet counting because the data potentially contains all control characters - * including LF. - */ - framingToUse = bIsCompressed ? TCP_FRAMING_OCTET_COUNTING : rqdFraming; - - /* now check if we need to add a line terminator. We need to - * copy the string in memory in this case, this is probably - * quicker than using writev and definitely quicker than doing - * two socket calls. - * rgerhards 2005-07-22 - * - * Some messages already contain a \n character at the end - * of the message. We append one only if we there is not - * already one. This seems the best fit, though this also - * means the message does not arrive unaltered at the final - * destination. But in the spirit of legacy syslog, this is - * probably the best to do... - * rgerhards 2005-07-20 - */ - - /* Build frame based on selected framing */ - if(framingToUse == TCP_FRAMING_OCTET_STUFFING) { - if((*(msg+len-1) != '\n')) { - /* in the malloc below, we need to add 2 to the length. The - * reason is that we a) add one character and b) len does - * not take care of the '\0' byte. Up until today, it was just - * +1 , which caused rsyslogd to sometimes dump core. - * I have added this comment so that the logic is not accidently - * changed again. rgerhards, 2005-10-25 - */ - if((buf = malloc((len + 2) * sizeof(char))) == NULL) { - /* extreme mem shortage, try to solve - * as good as we can. No point in calling - * any alarms, they might as well run out - * of memory (the risk is very high, so we - * do NOT risk that). If we have a message of - * more than 1 byte (what I guess), we simply - * overwrite the last character. - * rgerhards 2005-07-22 - */ - if(len > 1) { - *(msg+len-1) = '\n'; - } else { - /* we simply can not do anything in - * this case (its an error anyhow...). - */ - } - } else { - /* we got memory, so we can copy the message */ - memcpy(buf, msg, len); /* do not copy '\0' */ - *(buf+len) = '\n'; - *(buf+len+1) = '\0'; - msg = buf; /* use new one */ - ++len; /* care for the \n */ - } - } - } else { - /* Octect-Counting - * In this case, we need to always allocate a buffer. This is because - * we need to put a header in front of the message text - */ - char szLenBuf[16]; - int iLenBuf; - - /* important: the printf-mask is "%d<sp>" because there must be a - * space after the len! - *//* The chairs of the IETF syslog-sec WG have announced that it is - * consensus to do the octet count on the SYSLOG-MSG part only. I am - * now changing the code to reflect this. Hopefully, it will not change - * once again (there can no compatibility layer programmed for this). - * To be on the save side, I just comment the code out. I mark these - * comments with "IETF20061218". - * rgerhards, 2006-12-19 - */ - iLenBuf = snprintf(szLenBuf, sizeof(szLenBuf)/sizeof(char), "%d ", (int) len); - /* IETF20061218 iLenBuf = - snprintf(szLenBuf, sizeof(szLenBuf)/sizeof(char), "%d ", len + iLenBuf);*/ - - if((buf = malloc((len + iLenBuf) * sizeof(char))) == NULL) { - /* we are out of memory. This is an extreme situation. We do not - * call any alarm handlers because they most likely run out of mem, - * too. We are brave enough to call debug output, though. Other than - * that, there is nothing left to do. We can not sent the message (as - * in case of the other framing, because the message is incomplete. - * We could, however, send two chunks (header and text separate), but - * that would cause a lot of complexity in the code. So we think it - * is appropriate enough to just make sure we do not crash in this - * very unlikely case. For this, it is justified just to loose - * the message. Rgerhards, 2006-12-07 - */ - dbgprintf("Error: out of memory when building TCP octet-counted " - "frame. Message is lost, trying to continue.\n"); - ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY); - } - - memcpy(buf, szLenBuf, iLenBuf); /* header */ - memcpy(buf + iLenBuf, msg, len); /* message */ - len += iLenBuf; /* new message size */ - msg = buf; /* set message buffer */ - } - - /* frame building complete, on to actual sending */ - - *plen = len; - if(buf == NULL) { - /* msg not modified */ - *pbMustBeFreed = 0; - } else { - *pmsg = msg; - *pbMustBeFreed = 1; - } - -finalize_it: - RETiRet; -} - - -/* Sends a TCP message. It is first checked if the - * session is open and, if not, it is opened. Then the send - * is tried. If it fails, one silent re-try is made. If the send - * fails again, an error status (-1) is returned. If all goes well, - * 0 is returned. The TCP session is NOT torn down. - * For now, EAGAIN is ignored (causing message loss) - but it is - * hard to do something intelligent in this case. With this - * implementation here, we can not block and/or defer. Things are - * probably a bit better when we move to liblogging. The alternative - * would be to enhance the current select server with buffering and - * write descriptors. This seems not justified, given the expected - * short life span of this code (and the unlikeliness of this event). - * rgerhards 2005-07-06 - * This function is now expected to stay. Libloging won't be used for - * that purpose. I have added the param "len", because it is known by the - * caller and so saves us some time. Also, it MUST be given because there - * may be NULs inside msg so that we can not rely on strlen(). Please note - * that the restrictions outlined above do not existin in multi-threaded - * mode, which we assume will now be most often used. So there is no - * real issue with the potential message loss in single-threaded builds. - * rgerhards, 2006-11-30 - * I greatly restructured the function to be more generic and work - * with function pointers. So it now can be used with any type of transport, - * as long as it follows stream semantics. This was initially done to - * support plain TCP and GSS via common code. - */ -int TCPSend(void *pData, char *msg, size_t len, TCPFRAMINGMODE rqdFraming, - rsRetVal (*initFunc)(void*), - rsRetVal (*sendFunc)(void*, char*, size_t), - rsRetVal (*prepRetryFunc)(void*)) -{ - DEFiRet; - int bDone = 0; - int retry = 0; - int bMsgMustBeFreed = 0;/* must msg be freed at end of function? 0 - no, 1 - yes */ - - assert(pData != NULL); - assert(msg != NULL); - assert(len > 0); - - CHKiRet(TCPSendBldFrame(rqdFraming, &msg, &len, &bMsgMustBeFreed)); - - while(!bDone) { /* loop is broken when send succeeds or error occurs */ - CHKiRet(initFunc(pData)); - iRet = sendFunc(pData, msg, len); - - if(iRet == RS_RET_OK || retry > 0) { - /* we are done - either we succeeded or the retry failed */ - bDone = 1; - } else { /* OK, one retry */ - ++retry; - CHKiRet(prepRetryFunc(pData)); /* try to recover */ - } - } - -finalize_it: - if(bMsgMustBeFreed) - free(msg); - RETiRet; -} - - -/* ----------------------------------------------------------------- * - * END OF CODE THAT SHALL GO INTO ITS OWN MODULE * - * ----------------------------------------------------------------- */ - -#endif - -/* - * vi:set ai: +/* vi:set ai: */ |