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-rw-r--r--plugins/omudpspoof/Makefile.am8
-rw-r--r--plugins/omudpspoof/omudpspoof.c586
2 files changed, 594 insertions, 0 deletions
diff --git a/plugins/omudpspoof/Makefile.am b/plugins/omudpspoof/Makefile.am
new file mode 100644
index 00000000..79c495a0
--- /dev/null
+++ b/plugins/omudpspoof/Makefile.am
@@ -0,0 +1,8 @@
+pkglib_LTLIBRARIES = omudpspoof.la
+
+omudpspoof_la_SOURCES = omudpspoof.c
+omudpspoof_la_CPPFLAGS = $(RSRT_CFLAGS) $(PTHREADS_CFLAGS) $(UDPSPOOF_CFLAGS)
+omudpspoof_la_LDFLAGS = -module -avoid-version
+omudpspoof_la_LIBADD = $(UDPSPOOF_LIBS)
+
+EXTRA_DIST =
diff --git a/plugins/omudpspoof/omudpspoof.c b/plugins/omudpspoof/omudpspoof.c
new file mode 100644
index 00000000..abbe7940
--- /dev/null
+++ b/plugins/omudpspoof/omudpspoof.c
@@ -0,0 +1,586 @@
+/* omudpspoof.c
+ *
+ * This is a udp-based output module that support spoofing.
+ *
+ * NOTE: read comments in module-template.h to understand how this file
+ * works!
+ *
+ * --------------------------------------------------------------------------------
+ *
+ * USAGE NOTES:
+ * To use it create a template that puts the hostname-ip ahead of what you want to
+ * send, similar to
+ *
+ * $template TraditionalFwdFormat,"%fromhost-ip% <%pri%>%timegenerated% %HOSTNAME%
+ * %syslogtag%%msg%\n"
+ *
+ * *.* @10.0.0.100;TraditionalFwdFormat
+ *
+ * The one problem right now is that any logs sent from the local box will go out
+ * with a source IP of 127.0.0.1
+ *
+ * --------------------------------------------------------------------------------
+ *
+ * Note: this file builds on UDP spoofing code contributed by
+ * David Lang <david@lang.hm>. I then created a "real" rsyslog module
+ * out of that code and omfwd. I decided to make it a separate module because
+ * omfwd already mixes up too many things (TCP & UDP & a differnt modes,
+ * this has historic reasons), it would not be a good idea to also add
+ * spoofing to it. And, looking at the requirements, there is little in
+ * common between omfwd and this module.
+ *
+ * Copyright 2009 David Lang (spoofing code)
+ * Copyright 2009 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 <http://www.gnu.org/licenses/>.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ */
+#include "config.h"
+#include "rsyslog.h"
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <fnmatch.h>
+#include <assert.h>
+#include <errno.h>
+#include <ctype.h>
+#include <unistd.h>
+#ifdef USE_NETZIP
+#include <zlib.h>
+#endif
+#include "conf.h"
+#include "syslogd-types.h"
+#include "srUtils.h"
+#include "net.h"
+#include "template.h"
+#include "msg.h"
+#include "cfsysline.h"
+#include "module-template.h"
+#include "glbl.h"
+#include "errmsg.h"
+#include "dirty.h"
+
+
+#include <libnet.h>
+#define _BSD_SOURCE 1
+#define __BSD_SOURCE 1
+#define __FAVOR_BSD 1
+
+
+MODULE_TYPE_OUTPUT
+
+/* internal structures
+ */
+DEF_OMOD_STATIC_DATA
+DEFobjCurrIf(errmsg)
+DEFobjCurrIf(glbl)
+DEFobjCurrIf(net)
+
+typedef struct _instanceData {
+ char *host;
+ int *pSockArray; /* sockets to use for UDP */
+ int bIsAddrResolved; /* is hostname address resolved? 0 - no, 1 - yes */
+ struct addrinfo *f_addr;
+ int compressionLevel; /* 0 - no compression, else level for zlib */
+ char *port;
+} instanceData;
+
+/* config data */
+static uchar *pszTplName = NULL; /* name of the default template to use */
+
+
+/* add some variables needed for libnet */
+libnet_t *libnet_handle;
+libnet_ptag_t ip, ipo;
+libnet_ptag_t udp;
+char errbuf[LIBNET_ERRBUF_SIZE];
+u_short source_port=32000;
+
+/* forward definitions */
+static rsRetVal doTryResume(instanceData *pData);
+
+/* Close the UDP sockets.
+ * rgerhards, 2009-05-29
+ */
+static rsRetVal
+closeUDPSockets(instanceData *pData)
+{
+ DEFiRet;
+ assert(pData != NULL);
+ if(pData->pSockArray != NULL) {
+ net.closeUDPListenSockets(pData->pSockArray);
+ pData->pSockArray = NULL;
+ freeaddrinfo(pData->f_addr);
+ pData->f_addr = NULL;
+ }
+pData->bIsAddrResolved = 0; // TODO: remove this variable altogether
+ RETiRet;
+}
+
+
+/* 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.
+ */
+static char *getFwdPt(instanceData *pData)
+{
+ assert(pData != NULL);
+ if(pData->port == NULL)
+ return("514");
+ else
+ return(pData->port);
+}
+
+BEGINcreateInstance
+CODESTARTcreateInstance
+ /* Initialize the libnet library. Root priviledges are required.
+ * this initializes a IPv4 socket to use for forging UDP packets.
+ */
+ libnet_handle = libnet_init(
+ LIBNET_RAW4, /* injection type */
+ NULL, /* network interface */
+ errbuf); /* errbuf */
+
+ if (libnet_handle == NULL) {
+ fprintf(stderr, "libnet_init() failed: %s\n", errbuf);
+ exit(EXIT_FAILURE);
+ }
+
+ENDcreateInstance
+
+
+BEGINisCompatibleWithFeature
+CODESTARTisCompatibleWithFeature
+ if(eFeat == sFEATURERepeatedMsgReduction)
+ iRet = RS_RET_OK;
+ENDisCompatibleWithFeature
+
+
+BEGINfreeInstance
+CODESTARTfreeInstance
+ /* final cleanup */
+ closeUDPSockets(pData);
+ free(pData->port);
+ free(pData->host);
+ /* destroy the libnet state needed for forged UDP sources */
+ libnet_destroy(libnet_handle);
+ENDfreeInstance
+
+
+BEGINdbgPrintInstInfo
+CODESTARTdbgPrintInstInfo
+ dbgprintf("%s", pData->host);
+ENDdbgPrintInstInfo
+
+
+/* Send a message via UDP
+ * rgehards, 2007-12-20
+ */
+static rsRetVal UDPSend(instanceData *pData, char *msg, size_t len)
+{
+ struct addrinfo *r;
+ int lsent = 0;
+ int bSendSuccess;
+ int j, build_ip;
+ u_char opt[20];
+ u_char *source_text_ip;
+ struct sockaddr_in *tempaddr,source_ip;
+ DEFiRet;
+
+ if(pData->pSockArray == NULL) {
+ CHKiRet(doTryResume(pData));
+ }
+
+ ip = ipo = udp = 0;
+ if(source_port++ >= (u_short)42000){
+ source_port = 32000;
+ }
+ for(source_text_ip = (uchar*) msg; msg[0] != ' '; msg++ ,len--);
+ /* move the msg pointer to the first space in the message to strip off the IP address */
+ msg[0]='\0';
+ msg++;
+ inet_pton(AF_INET, (char*)source_text_ip, &(source_ip.sin_addr));
+
+ bSendSuccess = FALSE;
+ for (r = pData->f_addr; r; r = r->ai_next) {
+ tempaddr = (struct sockaddr_in *)r->ai_addr;
+ libnet_clear_packet(libnet_handle);
+ udp = libnet_build_udp(
+ source_port, /* source port */
+ tempaddr->sin_port, /* destination port */
+ LIBNET_UDP_H + len, /* packet length */
+ 0, /* checksum */
+ (u_char*)msg, /* payload */
+ len, /* payload size */
+ libnet_handle, /* libnet handle */
+ udp); /* libnet id */
+ if (udp == -1) {
+ dbgprintf("Can't build UDP header: %s\n", libnet_geterror(libnet_handle));
+ }
+
+ build_ip = 0;
+ /* this is not a legal options string */
+ for (j = 0; j < 20; j++) {
+ opt[j] = libnet_get_prand(LIBNET_PR2);
+ }
+ ipo = libnet_build_ipv4_options(opt, 20, libnet_handle, ipo);
+ if (ipo == -1) {
+ dbgprintf("Can't build IP options: %s\n", libnet_geterror(libnet_handle));
+ }
+ ip = libnet_build_ipv4(
+ LIBNET_IPV4_H + 20 + len + LIBNET_UDP_H, /* length */
+ 0, /* TOS */
+ 242, /* IP ID */
+ 0, /* IP Frag */
+ 64, /* TTL */
+ IPPROTO_UDP, /* protocol */
+ 0, /* checksum */
+ source_ip.sin_addr.s_addr,
+ tempaddr->sin_addr.s_addr,
+ NULL, /* payload */
+ 0, /* payload size */
+ libnet_handle, /* libnet handle */
+ ip); /* libnet id */
+ if (ip == -1) {
+ dbgprintf("Can't build IP header: %s\n", libnet_geterror(libnet_handle));
+ }
+
+ /* Write it to the wire. */
+ lsent = libnet_write(libnet_handle);
+ if (lsent == -1) {
+ dbgprintf("Write error: %s\n", libnet_geterror(libnet_handle));
+ } else {
+ bSendSuccess = TRUE;
+ break;
+ }
+ }
+ /* finished looping */
+ if (bSendSuccess == FALSE) {
+ dbgprintf("error forwarding via udp, suspending\n");
+ iRet = RS_RET_SUSPENDED;
+ }
+
+finalize_it:
+ RETiRet;
+}
+
+
+/* try to resume connection if it is not ready
+ * rgerhards, 2007-08-02
+ */
+static rsRetVal doTryResume(instanceData *pData)
+{
+ int iErr;
+ struct addrinfo *res;
+ struct addrinfo hints;
+ DEFiRet;
+
+ if(pData->pSockArray != NULL)
+ FINALIZE;
+
+ /* The remote address is not yet known and needs to be obtained */
+ dbgprintf(" %s\n", pData->host);
+ memset(&hints, 0, sizeof(hints));
+ /* port must be numeric, because config file syntax requires this */
+ hints.ai_flags = AI_NUMERICSERV;
+ hints.ai_family = glbl.GetDefPFFamily();
+ hints.ai_socktype = SOCK_DGRAM;
+ if((iErr = (getaddrinfo(pData->host, getFwdPt(pData), &hints, &res))) != 0) {
+ dbgprintf("could not get addrinfo for hostname '%s':'%s': %d%s\n",
+ pData->host, getFwdPt(pData), iErr, gai_strerror(iErr));
+ ABORT_FINALIZE(RS_RET_SUSPENDED);
+ }
+ dbgprintf("%s found, resuming.\n", pData->host);
+ pData->f_addr = res;
+ pData->bIsAddrResolved = 1;
+ pData->pSockArray = net.create_udp_socket((uchar*)pData->host, NULL, 0);
+
+finalize_it:
+ if(iRet != RS_RET_OK) {
+ if(pData->f_addr != NULL) {
+ freeaddrinfo(pData->f_addr);
+ pData->f_addr = NULL;
+ }
+ iRet = RS_RET_SUSPENDED;
+ }
+
+ RETiRet;
+}
+
+
+BEGINtryResume
+CODESTARTtryResume
+ iRet = doTryResume(pData);
+ENDtryResume
+
+BEGINdoAction
+ char *psz; /* temporary buffering */
+ register unsigned l;
+ int iMaxLine;
+CODESTARTdoAction
+ CHKiRet(doTryResume(pData));
+
+ iMaxLine = glbl.GetMaxLine();
+
+ dbgprintf(" %s:%s/udpspoofs\n", pData->host, getFwdPt(pData));
+
+ psz = (char*) ppString[0];
+ l = strlen((char*) psz);
+ if((int) l > iMaxLine)
+ l = iMaxLine;
+
+# 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;
+ uLongf destLen = sizeof(out) / sizeof(Bytef);
+ uLong srcLen = l;
+ int ret;
+ /* TODO: optimize malloc sequence? -- rgerhards, 2008-09-02 */
+ CHKmalloc(out = (Bytef*) malloc(iMaxLine + iMaxLine/100 + 12));
+ out[0] = 'z';
+ out[1] = '\0';
+ 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
+
+ CHKiRet(UDPSend(pData, psz, l));
+
+finalize_it:
+ENDdoAction
+
+
+BEGINparseSelectorAct
+ uchar *q;
+ int i;
+ int bErr;
+ struct addrinfo;
+CODESTARTparseSelectorAct
+CODE_STD_STRING_REQUESTparseSelectorAct(1)
+ /* first check if this config line is actually for us */
+ if(strncmp((char*) p, ":omudpspoof:", sizeof(":omudpspoof:") - 1)) {
+ ABORT_FINALIZE(RS_RET_CONFLINE_UNPROCESSED);
+ }
+
+ /* ok, if we reach this point, we have something for us */
+ p += sizeof(":omudpspoof:") - 1; /* eat indicator sequence (-1 because of '\0'!) */
+ CHKiRet(createInstance(&pData));
+
+ /* 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
+ * In order to support IPv6 addresses, we must introduce an extension to
+ * the hostname. If it is in square brackets, whatever is in them is treated as
+ * the hostname - without any exceptions ;) -- rgerhards, 2008-08-05
+ */
+ 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 {
+ errmsg.LogError(0, NO_ERRCODE, "Invalid compression level '%c' specified in "
+ "forwardig action - NOT turning on compression.",
+ *p);
+ }
+# else
+ errmsg.LogError(0, NO_ERRCODE, "Compression requested, but rsyslogd is not compiled "
+ "with compression support - request ignored.");
+# endif /* #ifdef USE_NETZIP */
+ } else { /* invalid option! Just skip it... */
+ errmsg.LogError(0, NO_ERRCODE, "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)
+ */
+ errmsg.LogError(0, NO_ERRCODE, "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
+ */
+ if(*p == '[') { /* everything is hostname upto ']' */
+ ++p; /* skip '[' */
+ for(q = p ; *p && *p != ']' ; ++p)
+ /* JUST SKIP */;
+ if(*p == ']') {
+ *p = '\0'; /* trick to obtain hostname (later)! */
+ ++p; /* eat it */
+ }
+ } else { /* traditional view of hostname */
+ for(q = p ; *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) {
+ errmsg.LogError(0, NO_ERRCODE, "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 getFwdPt(). */
+ } else {
+ memcpy(pData->port, tmp, i);
+ *(pData->port + i) = '\0';
+ }
+ }
+
+ /* now skip to template */
+ bErr = 0;
+ while(*p && *p != ';' && *p != '#' && !isspace((int) *p))
+ ++p; /*JUST SKIP*/
+
+ /* TODO: make this if go away! */
+ if(*p == ';' || *p == '#' || isspace(*p)) {
+ uchar cTmp = *p;
+ *p = '\0'; /* trick to obtain hostname (later)! */
+ CHKmalloc(pData->host = strdup((char*) q));
+ *p = cTmp;
+ } else {
+ CHKmalloc(pData->host = strdup((char*) q));
+ }
+
+ /* process template */
+ CHKiRet(cflineParseTemplateName(&p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS,
+ (pszTplName == NULL) ? (uchar*)"RSYSLOG_TraditionalForwardFormat" : pszTplName));
+
+CODE_STD_FINALIZERparseSelectorAct
+ENDparseSelectorAct
+
+
+/* a common function to free our configuration variables - used both on exit
+ * and on $ResetConfig processing. -- rgerhards, 2008-05-16
+ */
+static void
+freeConfigVars(void)
+{
+ if(pszTplName != NULL) {
+ free(pszTplName);
+ pszTplName = NULL;
+ }
+}
+
+
+BEGINmodExit
+CODESTARTmodExit
+ /* release what we no longer need */
+ objRelease(errmsg, CORE_COMPONENT);
+ objRelease(glbl, CORE_COMPONENT);
+ objRelease(net, LM_NET_FILENAME);
+
+ freeConfigVars();
+ENDmodExit
+
+
+BEGINqueryEtryPt
+CODESTARTqueryEtryPt
+CODEqueryEtryPt_STD_OMOD_QUERIES
+ENDqueryEtryPt
+
+
+/* Reset config variables for this module to default values.
+ * rgerhards, 2008-03-28
+ */
+static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal)
+{
+ freeConfigVars();
+ /* we now must reset all non-string values */
+ return RS_RET_OK;
+}
+
+
+BEGINmodInit()
+CODESTARTmodInit
+ *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */
+CODEmodInit_QueryRegCFSLineHdlr
+ CHKiRet(objUse(glbl, CORE_COMPONENT));
+ CHKiRet(objUse(errmsg, CORE_COMPONENT));
+ CHKiRet(objUse(net,LM_NET_FILENAME));
+
+ CHKiRet(regCfSysLineHdlr((uchar *)"actionudpspoofdefaulttemplate", 0, eCmdHdlrGetWord, NULL, &pszTplName, NULL));
+ CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler, resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID));
+ENDmodInit
+
+/* vim:set ai:
+ */
generated by cgit (git 2.34.1) at 2024-11-11 19:53:44 +0000