diff options
Diffstat (limited to 'plugins/mmexternal/mmexternal.c')
| -rw-r--r-- | plugins/mmexternal/mmexternal.c | 611 |
1 files changed, 611 insertions, 0 deletions
diff --git a/plugins/mmexternal/mmexternal.c b/plugins/mmexternal/mmexternal.c new file mode 100644 index 0000000..317420a --- /dev/null +++ b/plugins/mmexternal/mmexternal.c @@ -0,0 +1,611 @@ +/* mmexternal.c + * This core plugin is an interface module to message modification + * modules written in languages other than C. + * + * Copyright 2014-2018 by Rainer Gerhards + * + * This file is part of rsyslog. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * -or- + * see COPYING.ASL20 in the source distribution + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include "config.h" +#include <stdio.h> +#include <stdarg.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <signal.h> +#include <errno.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/wait.h> +#include <sys/uio.h> +#include "rsyslog.h" +#include "conf.h" +#include "syslogd-types.h" +#include "srUtils.h" +#include "module-template.h" +#include "msg.h" +#include "errmsg.h" +#include "cfsysline.h" +#include "glbl.h" +#include "rsconf.h" + + +MODULE_TYPE_OUTPUT +MODULE_TYPE_NOKEEP +MODULE_CNFNAME("mmexternal") + +/* internal structures + */ +DEF_OMOD_STATIC_DATA + +typedef struct _instanceData { + uchar *szBinary; /* name of binary to call */ + char **aParams; /* Optional Parameters for binary command */ + int iParams; /* Holds the count of parameters if set*/ + int bForceSingleInst; /* only a single wrkr instance of program permitted? */ + int inputProp; /* what to provide as input to the external program? */ +#define INPUT_MSG 0 +#define INPUT_RAWMSG 1 +#define INPUT_JSON 2 + uchar *outputFileName; /* name of file for std[out/err] or NULL if to discard */ + pthread_mutex_t mut; /* make sure only one instance is active */ +} instanceData; + +typedef struct wrkrInstanceData { + instanceData *pData; + pid_t pid; /* pid of currently running process */ + int fdOutput; /* it's fd (-1 if closed) */ + int fdPipeOut; /* file descriptor to write to */ + int fdPipeIn; /* fd we receive messages from the program (if we want to) */ + int bIsRunning; /* is binary currently running? 0-no, 1-yes */ + char *respBuf; /* buffer to read exernal plugin's response */ + int maxLenRespBuf; /* (current) maximum length of response buffer */ + int lenRespBuf; /* actual nbr of chars in response buffer */ + int idxRespBuf; /* last char read from response buffer */ +} wrkrInstanceData_t; + +typedef struct configSettings_s { + uchar *szBinary; /* name of binary to call */ +} configSettings_t; +static configSettings_t cs; + + +/* tables for interfacing with the v6 config system */ +/* action (instance) parameters */ +static struct cnfparamdescr actpdescr[] = { + { "binary", eCmdHdlrString, CNFPARAM_REQUIRED }, + { "interface.input", eCmdHdlrString, 0 }, + { "output", eCmdHdlrString, 0 }, + { "forcesingleinstance", eCmdHdlrBinary, 0 } +}; +static struct cnfparamblk actpblk = + { CNFPARAMBLK_VERSION, + sizeof(actpdescr)/sizeof(struct cnfparamdescr), + actpdescr + }; + +BEGINinitConfVars /* (re)set config variables to default values */ +CODESTARTinitConfVars + cs.szBinary = NULL; /* name of binary to call */ +ENDinitConfVars + +/* config settings */ + +BEGINcreateInstance +CODESTARTcreateInstance + pData->inputProp = INPUT_MSG; + pthread_mutex_init(&pData->mut, NULL); +ENDcreateInstance + +BEGINcreateWrkrInstance +CODESTARTcreateWrkrInstance + pWrkrData->fdPipeIn = -1; + pWrkrData->fdPipeOut = -1; + pWrkrData->fdOutput = -1; + pWrkrData->bIsRunning = 0; + pWrkrData->respBuf = NULL; + pWrkrData->maxLenRespBuf = 0; + pWrkrData->lenRespBuf = 0; + pWrkrData->idxRespBuf = 0; +ENDcreateWrkrInstance + + +BEGINisCompatibleWithFeature +CODESTARTisCompatibleWithFeature + if(eFeat == sFEATURERepeatedMsgReduction) + iRet = RS_RET_OK; +ENDisCompatibleWithFeature + + +BEGINfreeInstance + int i; +CODESTARTfreeInstance + pthread_mutex_destroy(&pData->mut); + free(pData->szBinary); + free(pData->outputFileName); + if(pData->aParams != NULL) { + for (i = 0; i < pData->iParams; i++) { + free(pData->aParams[i]); + } + free(pData->aParams); + } +ENDfreeInstance + +BEGINfreeWrkrInstance +CODESTARTfreeWrkrInstance + free(pWrkrData->respBuf); +ENDfreeWrkrInstance + + +BEGINdbgPrintInstInfo +CODESTARTdbgPrintInstInfo +ENDdbgPrintInstInfo + + +BEGINtryResume +CODESTARTtryResume +ENDtryResume + + +/* As this is just a debug function, we only make + * best effort to write the message but do *not* try very + * hard to handle errors. -- rgerhards, 2014-01-16 + */ +static void +writeOutputDebug(wrkrInstanceData_t *__restrict__ const pWrkrData, + const char *__restrict__ const buf, + const ssize_t lenBuf) +{ + char errStr[1024]; + ssize_t r; + + if(pWrkrData->pData->outputFileName == NULL) + goto done; + + if(pWrkrData->fdOutput == -1) { + pWrkrData->fdOutput = open((char*)pWrkrData->pData->outputFileName, + O_WRONLY | O_APPEND | O_CREAT, 0600); + if(pWrkrData->fdOutput == -1) { + DBGPRINTF("mmexternal: error opening output file %s: %s\n", + pWrkrData->pData->outputFileName, + rs_strerror_r(errno, errStr, sizeof(errStr))); + goto done; + } + } + + r = write(pWrkrData->fdOutput, buf, (size_t) lenBuf); + if(r != lenBuf) { + DBGPRINTF("mmexternal: problem writing output file %s: bytes " + "requested %lld, written %lld, msg: %s\n", + pWrkrData->pData->outputFileName, (long long) lenBuf, (long long) r, + rs_strerror_r(errno, errStr, sizeof(errStr))); + } +done: return; +} + + +/* Get reply from external program. Note that we *must* receive one + * reply for each message sent (half-duplex protocol). As such, the last + * char we read MUST be \n ... we cannot have multiple LF as this is + * forbidden by the plugin interface. We cannot have multiple responses + * for multiple messages, as we are in half-duplex mode! This makes + * things quite a bit simpler. So don't think the simple code does + * not handle those border-cases that are describe to cannot exist! + */ +static void +processProgramReply(wrkrInstanceData_t *__restrict__ const pWrkrData, smsg_t *const pMsg) +{ + rsRetVal iRet; + char errStr[1024]; + ssize_t r; + int numCharsRead; + char *newptr; + + numCharsRead = 0; + do { + if(pWrkrData->maxLenRespBuf < numCharsRead + 256) { /* 256 to permit at least a decent read */ + pWrkrData->maxLenRespBuf += 4096; + if((newptr = realloc(pWrkrData->respBuf, pWrkrData->maxLenRespBuf)) == NULL) { + DBGPRINTF("mmexternal: error realloc responseBuf: %s\n", + rs_strerror_r(errno, errStr, sizeof(errStr))); + /* emergency - fake no update */ + strcpy(pWrkrData->respBuf, "{}\n"); + numCharsRead = 3; + break; + } + pWrkrData->respBuf = newptr; + } + r = read(pWrkrData->fdPipeIn, pWrkrData->respBuf+numCharsRead, + pWrkrData->maxLenRespBuf-numCharsRead-1); + if(r > 0) { + numCharsRead += r; + pWrkrData->respBuf[numCharsRead] = '\0'; /* space reserved in read! */ + } else { + /* emergency - fake no update */ + strcpy(pWrkrData->respBuf, "{}\n"); + numCharsRead = 3; + } + if(Debug && r == -1) { + DBGPRINTF("mmexternal: error reading from external program: %s\n", + rs_strerror_r(errno, errStr, sizeof(errStr))); + } + } while(pWrkrData->respBuf[numCharsRead-1] != '\n'); + + writeOutputDebug(pWrkrData, pWrkrData->respBuf, numCharsRead); + /* strip LF, which is not part of the JSON message but framing */ + pWrkrData->respBuf[numCharsRead-1] = '\0'; + iRet = MsgSetPropsViaJSON(pMsg, (uchar*)pWrkrData->respBuf); + if(iRet != RS_RET_OK) { + LogError(0, iRet, "mmexternal: invalid reply '%s' from program '%s'", + pWrkrData->respBuf, pWrkrData->pData->szBinary); + } + + return; +} + + + +/* execute the child process (must be called in child context + * after fork). + * Note: all output will go to std[err/out] of the **child**, so + * rsyslog will never see it except as script output. Do NOT + * use dbgprintf() or LogError() and friends. + */ +static void __attribute__((noreturn)) +execBinary(wrkrInstanceData_t *pWrkrData, const int fdStdin, const int fdStdOutErr) +{ + int i; + struct sigaction sigAct; + sigset_t set; + char *newenviron[] = { NULL }; + + if(dup2(fdStdin, STDIN_FILENO) == -1) { + perror("mmexternal: dup() stdin failed\n"); + } + if(dup2(fdStdOutErr, STDOUT_FILENO) == -1) { + perror("mmexternal: dup() stdout failed\n"); + } + if(dup2(fdStdOutErr, STDERR_FILENO) == -1) { + perror("mmexternal: dup() stderr failed\n"); + } + + /* we close all file handles as we fork soon + * Is there a better way to do this? - mail me! rgerhards@adiscon.com + */ +# ifndef VALGRIND /* we can not use this with valgrind - too many errors... */ + for(i = 3 ; i <= 65535 ; ++i) + close(i); +# endif + + /* reset signal handlers to default */ + memset(&sigAct, 0, sizeof(sigAct)); + sigemptyset(&sigAct.sa_mask); + sigAct.sa_handler = SIG_DFL; + for(i = 1 ; i < NSIG ; ++i) + sigaction(i, &sigAct, NULL); + /* we need to block SIGINT, otherwise the external program is cancelled when we are + * stopped in debug mode. + */ + sigAct.sa_handler = SIG_IGN; + sigaction(SIGINT, &sigAct, NULL); + sigemptyset(&set); + sigprocmask(SIG_SETMASK, &set, NULL); + + alarm(0); + + /* finally exec child */ + execve((char*)pWrkrData->pData->szBinary, pWrkrData->pData->aParams, newenviron); + + /* we should never reach this point, but if we do, we complain and terminate */ + char errstr[1024]; + char errbuf[2048]; + rs_strerror_r(errno, errstr, sizeof(errstr)); + errstr[sizeof(errstr)-1] = '\0'; + const size_t lenbuf = snprintf(errbuf, sizeof(errbuf), + "mmexternal: failed to execute binary '%s': %s\n", + pWrkrData->pData->szBinary, errstr); + errbuf[sizeof(errbuf)-1] = '\0'; + if(write(2, errbuf, lenbuf) != (ssize_t) lenbuf) { + /* just keep static analyzers happy... */ + exit(2); + } + exit(1); +} + + +/* creates a pipe and starts program, uses pipe as stdin for program. + * rgerhards, 2009-04-01 + */ +static rsRetVal +openPipe(wrkrInstanceData_t *pWrkrData) +{ + int pipestdin[2]; + int pipestdout[2]; + pid_t cpid; + DEFiRet; + + if(pipe(pipestdin) == -1) { + ABORT_FINALIZE(RS_RET_ERR_CREAT_PIPE); + } + if(pipe(pipestdout) == -1) { + ABORT_FINALIZE(RS_RET_ERR_CREAT_PIPE); + } + + DBGPRINTF("mmexternal: executing program '%s' with '%d' parameters\n", + pWrkrData->pData->szBinary, pWrkrData->pData->iParams); + + /* final sanity check */ + assert(pWrkrData->pData->szBinary != NULL); + assert(pWrkrData->pData->aParams != NULL); + + /* NO OUTPUT AFTER FORK! */ + cpid = fork(); + if(cpid == -1) { + ABORT_FINALIZE(RS_RET_ERR_FORK); + } + pWrkrData->pid = cpid; + + if(cpid == 0) { + /* we are now the child, just exec the binary. */ + close(pipestdin[1]); /* close those pipe "ports" that */ + close(pipestdout[0]); /* we don't need */ + execBinary(pWrkrData, pipestdin[0], pipestdout[1]); + /*NO CODE HERE - WILL NEVER BE REACHED!*/ + } + + DBGPRINTF("mmexternal: child has pid %d\n", (int) cpid); + pWrkrData->fdPipeIn = dup(pipestdout[0]); + close(pipestdin[0]); + close(pipestdout[1]); + pWrkrData->pid = cpid; + pWrkrData->fdPipeOut = pipestdin[1]; + pWrkrData->bIsRunning = 1; +finalize_it: + RETiRet; +} + + +/* clean up after a terminated child + */ +static rsRetVal +cleanup(wrkrInstanceData_t *pWrkrData) +{ + int status; + int ret; + DEFiRet; + + assert(pWrkrData->bIsRunning == 1); + ret = waitpid(pWrkrData->pid, &status, 0); + + /* waitpid will fail with errno == ECHILD if the child process has already + been reaped by the rsyslogd main loop (see rsyslogd.c) */ + if(ret == pWrkrData->pid) { + glblReportChildProcessExit(runConf, pWrkrData->pData->szBinary, pWrkrData->pid, status); + } + + if(pWrkrData->fdOutput != -1) { + close(pWrkrData->fdOutput); + pWrkrData->fdOutput = -1; + } + if(pWrkrData->fdPipeIn != -1) { + close(pWrkrData->fdPipeIn); + pWrkrData->fdPipeIn = -1; + } + if(pWrkrData->fdPipeOut != -1) { + close(pWrkrData->fdPipeOut); + pWrkrData->fdPipeOut = -1; + } + pWrkrData->bIsRunning = 0; + pWrkrData->bIsRunning = 0; + RETiRet; +} + + +/* try to restart the binary when it has stopped. + */ +static rsRetVal +tryRestart(wrkrInstanceData_t *pWrkrData) +{ + DEFiRet; + assert(pWrkrData->bIsRunning == 0); + + iRet = openPipe(pWrkrData); + RETiRet; +} + +/* write to pipe + * note that we do not try to run block-free. If the users fears something + * may block (and this not be acceptable), the action should be run on its + * own action queue. + */ +static rsRetVal +callExtProg(wrkrInstanceData_t *__restrict__ const pWrkrData, smsg_t *__restrict__ const pMsg) +{ + int lenWritten; + int lenWrite; + int writeOffset; + int i_iov; + struct iovec iov[2]; + int bFreeInputstr = 1; /* we must only free if it does not point to msg-obj mem! */ + const uchar *inputstr = NULL; /* string to be processed by external program */ + DEFiRet; + + if(pWrkrData->pData->inputProp == INPUT_MSG) { + inputstr = getMSG(pMsg); + lenWrite = getMSGLen(pMsg); + bFreeInputstr = 0; + } else if(pWrkrData->pData->inputProp == INPUT_RAWMSG) { + getRawMsg(pMsg, (uchar**)&inputstr, &lenWrite); + bFreeInputstr = 0; + } else { + inputstr = msgGetJSONMESG(pMsg); + lenWrite = strlen((const char*)inputstr); + } + + writeOffset = 0; + do { + DBGPRINTF("mmexternal: writing to prog (fd %d, offset %d): %s\n", + pWrkrData->fdPipeOut, (int) writeOffset, inputstr); + i_iov = 0; + if(writeOffset < lenWrite) { + iov[0].iov_base = (char*)inputstr+writeOffset; + iov[0].iov_len = lenWrite - writeOffset; + ++i_iov; + } + iov[i_iov].iov_base = (void*)"\n"; + iov[i_iov].iov_len = 1; + lenWritten = writev(pWrkrData->fdPipeOut, iov, i_iov+1); + if(lenWritten == -1) { + switch(errno) { + case EPIPE: + LogMsg(0, RS_RET_ERR_WRITE_PIPE, LOG_WARNING, + "mmexternal: program '%s' (pid %ld) terminated; will be restarted", + pWrkrData->pData->szBinary, (long) pWrkrData->pid); + CHKiRet(cleanup(pWrkrData)); + CHKiRet(tryRestart(pWrkrData)); + writeOffset = 0; + break; + default: + LogError(errno, RS_RET_ERR_WRITE_PIPE, "mmexternal: error sending message to program"); + ABORT_FINALIZE(RS_RET_ERR_WRITE_PIPE); + break; + } + } else { + writeOffset += lenWritten; + } + } while(lenWritten != lenWrite+1); + + processProgramReply(pWrkrData, pMsg); + +finalize_it: + /* we need to free json input strings, only. All others point to memory + * inside the msg object, which is destroyed when the msg is destroyed. + */ + if(bFreeInputstr) { + free((void*)inputstr); + } + RETiRet; +} + + +BEGINdoAction_NoStrings + smsg_t **ppMsg = (smsg_t **) pMsgData; + smsg_t *pMsg = ppMsg[0]; + instanceData *pData; +CODESTARTdoAction + pData = pWrkrData->pData; + if(pData->bForceSingleInst) + pthread_mutex_lock(&pData->mut); + if(pWrkrData->bIsRunning == 0) { + openPipe(pWrkrData); + } + + iRet = callExtProg(pWrkrData, pMsg); + + if(iRet != RS_RET_OK) + iRet = RS_RET_SUSPENDED; + if(pData->bForceSingleInst) + pthread_mutex_unlock(&pData->mut); +ENDdoAction + + +static void +setInstParamDefaults(instanceData *pData) +{ + pData->szBinary = NULL; + pData->aParams = NULL; + pData->outputFileName = NULL; + pData->iParams = 0; + pData->bForceSingleInst = 0; +} + + +BEGINnewActInst + struct cnfparamvals *pvals; + int i; + const char *cstr = NULL; +CODESTARTnewActInst + if((pvals = nvlstGetParams(lst, &actpblk, NULL)) == NULL) { + ABORT_FINALIZE(RS_RET_MISSING_CNFPARAMS); + } + + CHKiRet(createInstance(&pData)); + setInstParamDefaults(pData); + + CODE_STD_STRING_REQUESTnewActInst(1) + for(i = 0 ; i < actpblk.nParams ; ++i) { + if(!pvals[i].bUsed) + continue; + if(!strcmp(actpblk.descr[i].name, "binary")) { + CHKiRet(split_binary_parameters(&pData->szBinary, &pData->aParams, &pData->iParams, + pvals[i].val.d.estr)); + } else if(!strcmp(actpblk.descr[i].name, "output")) { + pData->outputFileName = (uchar*)es_str2cstr(pvals[i].val.d.estr, NULL); + } else if(!strcmp(actpblk.descr[i].name, "forcesingleinstance")) { + pData->bForceSingleInst = (int) pvals[i].val.d.n; + } else if(!strcmp(actpblk.descr[i].name, "interface.input")) { + cstr = es_str2cstr(pvals[i].val.d.estr, NULL); + if(!strcmp(cstr, "msg")) + pData->inputProp = INPUT_MSG; + else if(!strcmp(cstr, "rawmsg")) + pData->inputProp = INPUT_RAWMSG; + else if(!strcmp(cstr, "fulljson")) + pData->inputProp = INPUT_JSON; + else { + LogError(0, RS_RET_INVLD_INTERFACE_INPUT, + "mmexternal: invalid interface.input parameter '%s'", + cstr); + ABORT_FINALIZE(RS_RET_INVLD_INTERFACE_INPUT); + } + } else { + DBGPRINTF("mmexternal: program error, non-handled param '%s'\n", actpblk.descr[i].name); + } + } + + CHKiRet(OMSRsetEntry(*ppOMSR, 0, NULL, OMSR_TPL_AS_MSG)); + DBGPRINTF("mmexternal: bForceSingleInst %d\n", pData->bForceSingleInst); + DBGPRINTF("mmexternal: interface.input '%s', mode %d\n", cstr, pData->inputProp); +CODE_STD_FINALIZERnewActInst + free((void*)cstr); + cnfparamvalsDestruct(pvals, &actpblk); +ENDnewActInst + +NO_LEGACY_CONF_parseSelectorAct + + +BEGINmodExit +CODESTARTmodExit + free(cs.szBinary); + cs.szBinary = NULL; +ENDmodExit + + +BEGINqueryEtryPt +CODESTARTqueryEtryPt +CODEqueryEtryPt_STD_OMOD_QUERIES +CODEqueryEtryPt_STD_OMOD8_QUERIES +CODEqueryEtryPt_STD_CONF2_CNFNAME_QUERIES +CODEqueryEtryPt_STD_CONF2_OMOD_QUERIES +ENDqueryEtryPt + +BEGINmodInit() +CODESTARTmodInit +INITLegCnfVars + *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */ +CODEmodInit_QueryRegCFSLineHdlr +CODEmodInit_QueryRegCFSLineHdlr +ENDmodInit |