/* omgssapi.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! * * 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 USE_GSSAPI #include "rsyslog.h" #include #include #include #include #include #include #include #include #include #include #include #include #ifdef USE_NETZIP #include #endif #include #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" #include "gss-misc.h" #include "errmsg.h" MODULE_TYPE_OUTPUT #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 */ /* internal structures */ DEF_OMOD_STATIC_DATA DEFobjCurrIf(errmsg) DEFobjCurrIf(gssutil) typedef struct _instanceData { char f_hname[MAXHOSTNAMELEN+1]; short sock; /* file descriptor */ 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; TCPFRAMINGMODE tcp_framing; time_t ttSuspend; /* time selector was suspended */ gss_ctx_id_t gss_context; OM_uint32 gss_flags; } instanceData; static char *gss_base_service_name = NULL; static enum gss_mode_t { GSSMODE_MIC, GSSMODE_ENC } gss_mode = GSSMODE_ENC; /* 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 OM_uint32 maj_stat, min_stat; 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; } if (pData->gss_context != GSS_C_NO_CONTEXT) { maj_stat = gss_delete_sec_context(&min_stat, &pData->gss_context, GSS_C_NO_BUFFER); if (maj_stat != GSS_S_COMPLETE) gssutil.display_status("deleting context", maj_stat, min_stat); } /* this is meant to be done when module is unloaded, but since this module is static... */ if (gss_base_service_name != NULL) { free(gss_base_service_name); gss_base_service_name = NULL; } /* final cleanup */ if(pData->sock >= 0) close(pData->sock); ENDfreeInstance BEGINdbgPrintInstInfo CODESTARTdbgPrintInstInfo printf("%s", pData->f_hname); ENDdbgPrintInstInfo /* CODE FOR SENDING TCP MESSAGES */ /* This function is called immediately before a send retry is attempted. * It shall clean up whatever makes sense. * rgerhards, 2007-12-28 */ static rsRetVal TCPSendGSSPrepRetry(void __attribute__((unused)) *pData) { /* in case of TCP/GSS, there is nothing to do */ return RS_RET_OK; } static rsRetVal TCPSendGSSInit(void *pvData) { DEFiRet; int s = -1; char *base; OM_uint32 maj_stat, min_stat, init_sec_min_stat, *sess_flags, ret_flags; gss_buffer_desc out_tok, in_tok; gss_buffer_t tok_ptr; gss_name_t target_name; gss_ctx_id_t *context; instanceData *pData = (instanceData *) pvData; assert(pData != NULL); /* if the socket is already initialized, we are done */ if(pData->sock > 0) ABORT_FINALIZE(RS_RET_OK); base = (gss_base_service_name == NULL) ? "host" : gss_base_service_name; out_tok.length = strlen(pData->f_hname) + strlen(base) + 2; if ((out_tok.value = malloc(out_tok.length)) == NULL) { ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY); } strcpy(out_tok.value, base); strcat(out_tok.value, "@"); strcat(out_tok.value, pData->f_hname); dbgprintf("GSS-API service name: %s\n", (char*) out_tok.value); tok_ptr = GSS_C_NO_BUFFER; context = &pData->gss_context; *context = GSS_C_NO_CONTEXT; maj_stat = gss_import_name(&min_stat, &out_tok, GSS_C_NT_HOSTBASED_SERVICE, &target_name); free(out_tok.value); out_tok.value = NULL; out_tok.length = 0; if (maj_stat != GSS_S_COMPLETE) { gssutil.display_status("parsing name", maj_stat, min_stat); goto fail; } sess_flags = &pData->gss_flags; *sess_flags = GSS_C_MUTUAL_FLAG; if (gss_mode == GSSMODE_MIC) { *sess_flags |= GSS_C_INTEG_FLAG; } if (gss_mode == GSSMODE_ENC) { *sess_flags |= GSS_C_CONF_FLAG; } dbgprintf("GSS-API requested context flags:\n"); gssutil.display_ctx_flags(*sess_flags); do { maj_stat = gss_init_sec_context(&init_sec_min_stat, GSS_C_NO_CREDENTIAL, context, target_name, GSS_C_NO_OID, *sess_flags, 0, NULL, tok_ptr, NULL, &out_tok, &ret_flags, NULL); if (tok_ptr != GSS_C_NO_BUFFER) free(in_tok.value); if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED) { gssutil.display_status("initializing context", maj_stat, init_sec_min_stat); goto fail; } if (s == -1) if ((s = pData->sock = TCPSendCreateSocket(pData->f_addr)) == -1) goto fail; if (out_tok.length != 0) { dbgprintf("GSS-API Sending init_sec_context token (length: %ld)\n", (long) out_tok.length); if (gssutil.send_token(s, &out_tok) < 0) { goto fail; } } gss_release_buffer(&min_stat, &out_tok); if (maj_stat == GSS_S_CONTINUE_NEEDED) { dbgprintf("GSS-API Continue needed...\n"); if (gssutil.recv_token(s, &in_tok) <= 0) { goto fail; } tok_ptr = &in_tok; } } while (maj_stat == GSS_S_CONTINUE_NEEDED); dbgprintf("GSS-API Provided context flags:\n"); *sess_flags = ret_flags; gssutil.display_ctx_flags(*sess_flags); dbgprintf("GSS-API Context initialized\n"); gss_release_name(&min_stat, &target_name); finalize_it: RETiRet; fail: errmsg.LogError(NO_ERRCODE, "GSS-API Context initialization failed\n"); gss_release_name(&min_stat, &target_name); gss_release_buffer(&min_stat, &out_tok); if (*context != GSS_C_NO_CONTEXT) { gss_delete_sec_context(&min_stat, context, GSS_C_NO_BUFFER); *context = GSS_C_NO_CONTEXT; } if (s != -1) close(s); pData->sock = -1; ABORT_FINALIZE(RS_RET_GSS_SENDINIT_ERROR); } static rsRetVal TCPSendGSSSend(void *pvData, char *msg, size_t len) { int s; gss_ctx_id_t *context; OM_uint32 maj_stat, min_stat; gss_buffer_desc in_buf, out_buf; instanceData *pData = (instanceData *) pvData; assert(pData != NULL); assert(msg != NULL); assert(len > 0); s = pData->sock; context = &pData->gss_context; in_buf.value = msg; in_buf.length = len; maj_stat = gss_wrap(&min_stat, *context, (gss_mode == GSSMODE_ENC) ? 1 : 0, GSS_C_QOP_DEFAULT, &in_buf, NULL, &out_buf); if (maj_stat != GSS_S_COMPLETE) { gssutil.display_status("wrapping message", maj_stat, min_stat); goto fail; } if (gssutil.send_token(s, &out_buf) < 0) { goto fail; } gss_release_buffer(&min_stat, &out_buf); return RS_RET_OK; fail: close(s); pData->sock = -1; gss_delete_sec_context(&min_stat, context, GSS_C_NO_BUFFER); *context = GSS_C_NO_CONTEXT; gss_release_buffer(&min_stat, &out_buf); dbgprintf("message not (GSS/tcp)send"); return RS_RET_GSS_SEND_ERROR; } /* 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 = 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 omgssapi.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), "tcp-gssapi"); 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 CHKiRet_Hdlr(TCPSend(pData, psz, l, pData->tcp_framing, TCPSendGSSInit, TCPSendGSSSend, TCPSendGSSPrepRetry)) { /* error! */ dbgprintf("error forwarding via tcp, suspending\n"); pData->eDestState = eDestFORW_SUSP; iRet = RS_RET_SUSPENDED; } break; } ENDdoAction BEGINparseSelectorAct uchar *q; int i; int error; int bErr; struct addrinfo hints, *res; CODESTARTparseSelectorAct CODE_STD_STRING_REQUESTparseSelectorAct(1) /* first check if this config line is actually for us * The first test [*p == '>'] can be skipped if a module shall only * support the newer slection syntax [:modname:]. This is in fact * recommended for new modules. Please note that over time this part * will be handled by rsyslogd itself, but for the time being it is * a good compromise to do it at the module level. * rgerhards, 2007-10-15 */ if(!strncmp((char*) p, ":omgssapi:", sizeof(":omgssapi:") - 1)) { p += sizeof(":omgssapi:") - 1; /* eat indicator sequence (-1 because of '\0'!) */ } else { ABORT_FINALIZE(RS_RET_CONFLINE_UNPROCESSED); } /* ok, if we reach this point, we have something for us */ if((iRet = createInstance(&pData)) != RS_RET_OK) goto finalize_it; /* 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 { errmsg.LogError(NO_ERRCODE, "Invalid compression level '%c' specified in " "forwardig action - NOT turning on compression.", *p); } # else errmsg.LogError(NO_ERRCODE, "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... */ errmsg.LogError(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(NO_ERRCODE, "Option block not terminated in gssapi forward 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) { errmsg.LogError(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 * 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; errmsg.LogError(NO_ERRCODE, "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 = 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; } /* 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_FALSE; ENDneedUDPSocket BEGINmodExit CODESTARTmodExit ENDmodExit BEGINqueryEtryPt CODESTARTqueryEtryPt CODEqueryEtryPt_STD_OMOD_QUERIES ENDqueryEtryPt /* set a new GSSMODE based on config directive */ static rsRetVal setGSSMode(void __attribute__((unused)) *pVal, uchar *mode) { DEFiRet; if (!strcmp((char *) mode, "integrity")) { gss_mode = GSSMODE_MIC; dbgprintf("GSS-API gssmode set to GSSMODE_MIC\n"); } else if (!strcmp((char *) mode, "encryption")) { gss_mode = GSSMODE_ENC; dbgprintf("GSS-API gssmode set to GSSMODE_ENC\n"); } else { errmsg.LogError(NO_ERRCODE, "unknown gssmode parameter: %s", (char *) mode); iRet = RS_RET_INVALID_PARAMS; } free(mode); RETiRet; } static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal) { gss_mode = GSSMODE_ENC; if (gss_base_service_name != NULL) { free(gss_base_service_name); gss_base_service_name = NULL; } return RS_RET_OK; } BEGINmodInit() CODESTARTmodInit *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */ CODEmodInit_QueryRegCFSLineHdlr CHKiRet(objUse(errmsg, CORE_COMPONENT)); CHKiRet(objUse(gssutil, "gssutil")); CHKiRet(omsdRegCFSLineHdlr((uchar *)"gssforwardservicename", 0, eCmdHdlrGetWord, NULL, &gss_base_service_name, STD_LOADABLE_MODULE_ID)); CHKiRet(omsdRegCFSLineHdlr((uchar *)"gssmode", 0, eCmdHdlrGetWord, setGSSMode, &gss_mode, STD_LOADABLE_MODULE_ID)); CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler, resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID)); ENDmodInit #endif /* #ifdef USE_GSSAPI */ /* * vi:set ai: */