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authorRainer Gerhards <rgerhards@adiscon.com>2008-03-12 14:08:21 +0000
committerRainer Gerhards <rgerhards@adiscon.com>2008-03-12 14:08:21 +0000
commit618a7f6a220563a50909d0e15eb90ce222aced31 (patch)
tree484439581a66494bbed91aa6e53f4b571126e820 /tcpsyslog.c
parent9ddee5b38772f42f4371c6828a832f0d6267251d (diff)
downloadrsyslog-618a7f6a220563a50909d0e15eb90ce222aced31.tar.gz
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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.c284
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:
*/