diff options
Diffstat (limited to 'plugins/ommail/ommail.c')
| -rw-r--r-- | plugins/ommail/ommail.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/plugins/ommail/ommail.c b/plugins/ommail/ommail.c new file mode 100644 index 00000000..218c73c9 --- /dev/null +++ b/plugins/ommail/ommail.c @@ -0,0 +1,630 @@ +/* ommail.c + * + * This is an implementation of a mail sending output module. So far, we + * only support direct SMTP, that is talking to a SMTP server. In the long + * term, support for using sendmail should also be implemented. Please note + * that the SMTP protocol implementation is a very bare one. We support + * RFC821/822 messages, without any authentication and any other nice + * features (no MIME, no nothing). It is assumed that proper firewalling + * and/or STMP server configuration is used together with this module. + * + * NOTE: read comments in module-template.h to understand how this file + * works! + * + * File begun on 2008-04-04 by RGerhards + * + * Copyright 2008 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 <assert.h> +#include <unistd.h> +#include <errno.h> +#include <netdb.h> +#include <time.h> +#include <sys/socket.h> +#include "syslogd.h" +#include "syslogd-types.h" +#include "srUtils.h" +#include "cfsysline.h" +#include "module-template.h" +#include "errmsg.h" + +MODULE_TYPE_OUTPUT + +/* internal structures + */ +DEF_OMOD_STATIC_DATA +DEFobjCurrIf(errmsg) + +static uchar *pszSrv = NULL; +static uchar *pszSrvPort = NULL; +static uchar *pszFrom = NULL; +static uchar *pszTo = NULL; +static uchar *pszSubject = NULL; +static int bEnableBody = 1; /* should a mail body be generated? (set to 0 eg for SMS gateways) */ + +typedef struct _instanceData { + int iMode; /* 0 - smtp, 1 - sendmail */ + int bHaveSubject; /* is a subject configured? (if so, it is the second string provided by rsyslog core) */ + int bEnableBody; /* is a body configured? (if so, it is the second string provided by rsyslog core) */ + union { + struct { + uchar *pszSrv; + uchar *pszSrvPort; + uchar *pszFrom; + uchar *pszTo; + char RcvBuf[1024]; /* buffer for receiving server responses */ + size_t lenRcvBuf; + size_t iRcvBuf; /* current index into the rcvBuf (buf empty if iRcvBuf == lenRcvBuf) */ + int sock; /* socket to this server (most important when we do multiple msgs per mail) */ + } smtp; + } md; /* mode-specific data */ +} instanceData; + + +BEGINcreateInstance +CODESTARTcreateInstance +ENDcreateInstance + + +BEGINisCompatibleWithFeature +CODESTARTisCompatibleWithFeature + if(eFeat == sFEATURERepeatedMsgReduction) + iRet = RS_RET_OK; +ENDisCompatibleWithFeature + + +BEGINfreeInstance +CODESTARTfreeInstance + if(pData->iMode == 0) { + if(pData->md.smtp.pszSrv != NULL) + free(pData->md.smtp.pszSrv); + if(pData->md.smtp.pszSrvPort != NULL) + free(pData->md.smtp.pszSrvPort); + if(pData->md.smtp.pszFrom != NULL) + free(pData->md.smtp.pszFrom); + if(pData->md.smtp.pszTo != NULL) + free(pData->md.smtp.pszTo); + } +ENDfreeInstance + + +BEGINdbgPrintInstInfo +CODESTARTdbgPrintInstInfo + printf("mail"); /* TODO: extend! */ +ENDdbgPrintInstInfo + + +/* TCP support code, should probably be moved to net.c or some place else... -- rgerhards, 2008-04-04 */ + +/* "receive" a character from the remote server. A single character + * is returned. Returns RS_RET_NO_MORE_DATA if the server has closed + * the connection and RS_RET_IO_ERROR if something goes wrong. This + * is a blocking read. + * rgerhards, 2008-04-04 + */ +static rsRetVal +getRcvChar(instanceData *pData, char *pC) +{ + DEFiRet; + ssize_t lenBuf; + assert(pData != NULL); + + if(pData->md.smtp.iRcvBuf == pData->md.smtp.lenRcvBuf) { /* buffer empty? */ + /* yes, we need to read the next server response */ + do { + lenBuf = recv(pData->md.smtp.sock, pData->md.smtp.RcvBuf, sizeof(pData->md.smtp.RcvBuf), 0); + if(lenBuf == 0) { + ABORT_FINALIZE(RS_RET_NO_MORE_DATA); + } else if(lenBuf < 0) { + if(errno != EAGAIN) { + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + } else { + /* good read */ + pData->md.smtp.iRcvBuf = 0; + pData->md.smtp.lenRcvBuf = lenBuf; + } + + } while(lenBuf < 1); + } + + /* when we reach this point, we have a non-empty buffer */ + *pC = pData->md.smtp.RcvBuf[pData->md.smtp.iRcvBuf++]; + +finalize_it: + RETiRet; +} + + +/* close the mail server connection + * rgerhards, 2008-04-08 + */ +static rsRetVal +serverDisconnect(instanceData *pData) +{ + DEFiRet; + assert(pData != NULL); + + if(pData->md.smtp.sock != -1) { + close(pData->md.smtp.sock); + pData->md.smtp.sock = -1; + } + + RETiRet; +} + + +/* open a connection to the mail server + * rgerhards, 2008-04-04 + */ +static rsRetVal +serverConnect(instanceData *pData) +{ + struct addrinfo *res = NULL; + struct addrinfo hints; + char *smtpPort; + char *smtpSrv; + char errStr[1024]; + + DEFiRet; + assert(pData != NULL); + + if(pData->md.smtp.pszSrv == NULL) + smtpSrv = "127.0.0.1"; + else + smtpSrv = (char*)pData->md.smtp.pszSrv; + + if(pData->md.smtp.pszSrvPort == NULL) + smtpPort = "25"; + else + smtpPort = (char*)pData->md.smtp.pszSrvPort; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = AF_UNSPEC; /* TODO: make configurable! */ + hints.ai_socktype = SOCK_STREAM; + if(getaddrinfo(smtpSrv, smtpPort, &hints, &res) != 0) { + dbgprintf("error %d in getaddrinfo\n", errno); + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + + if((pData->md.smtp.sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1) { + dbgprintf("couldn't create send socket, reason %s", rs_strerror_r(errno, errStr, sizeof(errStr))); + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + + if(connect(pData->md.smtp.sock, res->ai_addr, res->ai_addrlen) != 0) { + dbgprintf("create tcp connection failed, reason %s", rs_strerror_r(errno, errStr, sizeof(errStr))); + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + +finalize_it: + if(res != NULL) + freeaddrinfo(res); + + if(iRet != RS_RET_OK) { + if(pData->md.smtp.sock != -1) { + close(pData->md.smtp.sock); + pData->md.smtp.sock = -1; + } + } + + RETiRet; +} + + +/* send text to the server, blocking send */ +static rsRetVal +Send(int sock, char *msg, size_t len) +{ + DEFiRet; + size_t offsBuf = 0; + ssize_t lenSend; + + assert(msg != NULL); + + if(len == 0) /* it's valid, but does not make much sense ;) */ + FINALIZE; + + do { + lenSend = send(sock, msg + offsBuf, len - offsBuf, 0); + if(lenSend == -1) { + if(errno != EAGAIN) { + dbgprintf("message not (tcp)send, errno %d", errno); + ABORT_FINALIZE(RS_RET_TCP_SEND_ERROR); + } + } else if(lenSend != (ssize_t) len) { + offsBuf += len; /* on to next round... */ + } else { + FINALIZE; + } + } while(1); + +finalize_it: + RETiRet; +} + + +/* send body text to the server, blocking send + * The body is special in that we must escape a leading dot inside a line + */ +static rsRetVal +bodySend(instanceData *pData, char *msg, size_t len) +{ + DEFiRet; + char szBuf[2048]; + size_t iSrc; + size_t iBuf = 0; + int bHadCR = 0; + int bInStartOfLine = 1; + + assert(pData != NULL); + assert(msg != NULL); + + for(iSrc = 0 ; iSrc < len ; ++iSrc) { + if(iBuf >= sizeof(szBuf) - 1) { /* one is reserved for our extra dot */ + CHKiRet(Send(pData->md.smtp.sock, szBuf, iBuf)); + iBuf = 0; + } + szBuf[iBuf++] = msg[iSrc]; + switch(msg[iSrc]) { + case '\r': + bHadCR = 1; + break; + case '\n': + if(bHadCR) + bInStartOfLine = 1; + bHadCR = 0; + break; + case '.': + if(bInStartOfLine) + szBuf[iBuf++] = '.'; /* space is always reserved for this! */ + /*FALLTHROUGH*/ + default: + bInStartOfLine = 0; + bHadCR = 0; + break; + } + } + + if(iBuf > 0) { /* incomplete buffer to send (the *usual* case)? */ + CHKiRet(Send(pData->md.smtp.sock, szBuf, iBuf)); + } + +finalize_it: + RETiRet; +} + + +/* read response line from server + */ +static rsRetVal +readResponseLn(instanceData *pData, char *pLn, size_t lenLn) +{ + DEFiRet; + size_t i = 0; + char c; + + assert(pData != NULL); + assert(pLn != NULL); + + do { + CHKiRet(getRcvChar(pData, &c)); + if(c == '\n') + break; + if(i < (lenLn - 1)) /* if line is too long, we simply discard the rest */ + pLn[i++] = c; + } while(1); + pLn[i] = '\0'; + dbgprintf("smtp server response: %s\n", pLn); /* do not remove, this is helpful in troubleshooting SMTP probs! */ + +finalize_it: + RETiRet; +} + + +/* read numerical response code from server and compare it to requried response code. + * If they two don't match, return RS_RET_SMTP_ERROR. + * rgerhards, 2008-04-07 + */ +static rsRetVal +readResponse(instanceData *pData, int *piState, int iExpected) +{ + DEFiRet; + int bCont; + char buf[128]; + + assert(pData != NULL); + assert(piState != NULL); + + bCont = 1; + do { + CHKiRet(readResponseLn(pData, buf, sizeof(buf))); + /* note: the code below is not 100% clean as we may have received less than 4 characters. + * However, as we have a fixed size this will not create a vulnerability. An error will + * also most likely be generated, so it is quite acceptable IMHO -- rgerhards, 2008-04-08 + */ + if(buf[3] != '-') { /* last or only response line? */ + bCont = 0; + *piState = buf[0] - '0'; + *piState = *piState * 10 + buf[1] - '0'; + *piState = *piState * 10 + buf[2] - '0'; + if(*piState != iExpected) + ABORT_FINALIZE(RS_RET_SMTP_ERROR); + } + } while(bCont); + +finalize_it: + RETiRet; +} + + +/* create a timestamp suitable for use with the Date: SMTP body header + * rgerhards, 2008-04-08 + */ +static void +mkSMTPTimestamp(uchar *pszBuf, size_t lenBuf) +{ + time_t tCurr; + struct tm tmCurr; + static const char szDay[][4] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}; + static const char szMonth[][4] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; + + time(&tCurr); + gmtime_r(&tCurr, &tmCurr); + snprintf((char*)pszBuf, lenBuf, "Date: %s, %2d %s %4d %2d:%02d:%02d UT\r\n", szDay[tmCurr.tm_wday], tmCurr.tm_mday, + szMonth[tmCurr.tm_mon], 1900 + tmCurr.tm_year, tmCurr.tm_hour, tmCurr.tm_min, tmCurr.tm_sec); +} + + +/* send a message via SMTP + * rgerhards, 2008-04-04 + */ +static rsRetVal +sendSMTP(instanceData *pData, uchar *body, uchar *subject) +{ + DEFiRet; + int iState; /* SMTP state */ + uchar szDateBuf[64]; + + assert(pData != NULL); + + CHKiRet(serverConnect(pData)); + CHKiRet(readResponse(pData, &iState, 220)); + + CHKiRet(Send(pData->md.smtp.sock, "HELO ", 5)); + CHKiRet(Send(pData->md.smtp.sock, (char*)LocalHostName, strlen((char*)LocalHostName))); + CHKiRet(Send(pData->md.smtp.sock, "\r\n", sizeof("\r\n") - 1)); + CHKiRet(readResponse(pData, &iState, 250)); + + CHKiRet(Send(pData->md.smtp.sock, "MAIL FROM: <", sizeof("MAIL FROM: <") - 1)); + CHKiRet(Send(pData->md.smtp.sock, (char*)pData->md.smtp.pszFrom, strlen((char*)pData->md.smtp.pszFrom))); + CHKiRet(Send(pData->md.smtp.sock, ">\r\n", sizeof(">\r\n") - 1)); + CHKiRet(readResponse(pData, &iState, 250)); + + CHKiRet(Send(pData->md.smtp.sock, "RCPT TO: <", sizeof("RCPT TO: <") - 1)); + CHKiRet(Send(pData->md.smtp.sock, (char*)pData->md.smtp.pszTo, strlen((char*)pData->md.smtp.pszTo))); + CHKiRet(Send(pData->md.smtp.sock, ">\r\n", sizeof(">\r\n") - 1)); + CHKiRet(readResponse(pData, &iState, 250)); + + CHKiRet(Send(pData->md.smtp.sock, "DATA\r\n", sizeof("DATA\r\n") - 1)); + CHKiRet(readResponse(pData, &iState, 354)); + + /* now come the data part */ + /* header */ + mkSMTPTimestamp(szDateBuf, sizeof(szDateBuf)); + CHKiRet(Send(pData->md.smtp.sock, (char*)szDateBuf, strlen((char*)szDateBuf))); + + CHKiRet(Send(pData->md.smtp.sock, "From: <", sizeof("From: <") - 1)); + CHKiRet(Send(pData->md.smtp.sock, (char*)pData->md.smtp.pszFrom, strlen((char*)pData->md.smtp.pszFrom))); + CHKiRet(Send(pData->md.smtp.sock, ">\r\n", sizeof(">\r\n") - 1)); + + CHKiRet(Send(pData->md.smtp.sock, "To: <", sizeof("To: <") - 1)); + CHKiRet(Send(pData->md.smtp.sock, (char*)pData->md.smtp.pszTo, strlen((char*)pData->md.smtp.pszTo))); + CHKiRet(Send(pData->md.smtp.sock, ">\r\n", sizeof(">\r\n") - 1)); + + CHKiRet(Send(pData->md.smtp.sock, "Subject: ", sizeof("Subject: ") - 1)); + CHKiRet(Send(pData->md.smtp.sock, (char*)subject, strlen((char*)subject))); + CHKiRet(Send(pData->md.smtp.sock, "\r\n", sizeof("\r\n") - 1)); + + CHKiRet(Send(pData->md.smtp.sock, "X-Mailer: rsyslog-immail\r\n", sizeof("x-mailer: rsyslog-immail\r\n") - 1)); + + CHKiRet(Send(pData->md.smtp.sock, "\r\n", sizeof("\r\n") - 1)); /* indicate end of header */ + + /* body */ + if(pData->bEnableBody) + CHKiRet(bodySend(pData, (char*)body, strlen((char*) body))); + + /* end of data, back to envelope transaction */ + CHKiRet(Send(pData->md.smtp.sock, "\r\n.\r\n", sizeof("\r\n.\r\n") - 1)); + CHKiRet(readResponse(pData, &iState, 250)); + + CHKiRet(Send(pData->md.smtp.sock, "QUIT\r\n", sizeof("QUIT\r\n") - 1)); + CHKiRet(readResponse(pData, &iState, 221)); + + /* we are finished, a new connection is created for each request, so let's close it now */ + CHKiRet(serverDisconnect(pData)); + +finalize_it: + RETiRet; +} + + +/* in tryResume we check if we can connect to the server in question. If that is OK, + * we close the connection without doing any actual SMTP transaction. It will be + * reopened during the actual send process. This may not be the best way to do it if + * there is a problem inside the SMTP transaction. However, we can't find that out without + * actually initiating something, and that would be bad. The logic here helps us + * correctly recover from an unreachable/down mail server, which is probably the majority + * of problem cases. For SMTP transaction problems, we will do lots of retries, but if it + * is a temporary problem, it will be fixed anyhow. So I consider this implementation to + * be clean enough, especially as I think other approaches have other weaknesses. + * rgerhards, 2008-04-08 + */ +BEGINtryResume +CODESTARTtryResume + CHKiRet(serverConnect(pData)); + CHKiRet(serverDisconnect(pData)); /* if we fail, we will never reach this line */ +finalize_it: + if(iRet == RS_RET_IO_ERROR) + iRet = RS_RET_SUSPENDED; +ENDtryResume + + +BEGINdoAction +CODESTARTdoAction + dbgprintf(" Mail\n"); + + /* forward */ + if(pData->bHaveSubject) + iRet = sendSMTP(pData, ppString[0], ppString[1]); + else + iRet = sendSMTP(pData, ppString[0], (uchar*)"message from rsyslog"); + + if(iRet != RS_RET_OK) { + /* error! */ + dbgprintf("error sending mail, suspending\n"); + iRet = RS_RET_SUSPENDED; + } +ENDdoAction + + +BEGINparseSelectorAct +CODESTARTparseSelectorAct + if(!strncmp((char*) p, ":ommail:", sizeof(":ommail:") - 1)) { + p += sizeof(":ommail:") - 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) + FINALIZE; + + /* TODO: check strdup() result */ + + if(pszFrom == NULL) { + errmsg.LogError(NO_ERRCODE, "no sender address given - specify $ActionMailFrom"); + ABORT_FINALIZE(RS_RET_MAIL_NO_FROM); + } + if(pszTo == NULL) { + errmsg.LogError(NO_ERRCODE, "no recipient address given - specify $ActionMailTo"); + ABORT_FINALIZE(RS_RET_MAIL_NO_TO); + } + + pData->md.smtp.pszFrom = (uchar*) strdup((char*)pszFrom); + pData->md.smtp.pszTo = (uchar*) strdup((char*)pszTo); + + if(pszSubject == NULL) { + /* if no subject is configured, we need just one template string */ + CODE_STD_STRING_REQUESTparseSelectorAct(1) + } else { + CODE_STD_STRING_REQUESTparseSelectorAct(2) + pData->bHaveSubject = 1; + CHKiRet(OMSRsetEntry(*ppOMSR, 1, (uchar*)strdup((char*) pszSubject), OMSR_NO_RQD_TPL_OPTS)); + } + if(pszSrv != NULL) + pData->md.smtp.pszSrv = (uchar*) strdup((char*)pszSrv); + if(pszSrvPort != NULL) + pData->md.smtp.pszSrvPort = (uchar*) strdup((char*)pszSrvPort); + pData->bEnableBody = bEnableBody; + + /* process template */ + CHKiRet(cflineParseTemplateName(&p, *ppOMSR, 0, OMSR_NO_RQD_TPL_OPTS, (uchar*) "RSYSLOG_FileFormat")); +CODE_STD_FINALIZERparseSelectorAct +ENDparseSelectorAct + + +/* Free string config variables and reset them to NULL (not necessarily the default!) */ +static rsRetVal freeConfigVariables(void) +{ + DEFiRet; + + if(pszSrv != NULL) { + free(pszSrv); + pszSrv = NULL; + } + if(pszSrvPort != NULL) { + free(pszSrvPort); + pszSrvPort = NULL; + } + if(pszFrom != NULL) { + free(pszFrom); + pszFrom = NULL; + } + if(pszTo != NULL) { + free(pszTo); + pszTo = NULL; + } + + RETiRet; +} + + +BEGINmodExit +CODESTARTmodExit + /* cleanup our allocations */ + freeConfigVariables(); + + /* release what we no longer need */ + objRelease(errmsg, CORE_COMPONENT); +ENDmodExit + + +BEGINqueryEtryPt +CODESTARTqueryEtryPt +CODEqueryEtryPt_STD_OMOD_QUERIES +ENDqueryEtryPt + + +/* Reset config variables for this module to default values. + */ +static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal) +{ + DEFiRet; + bEnableBody = 1; + iRet = freeConfigVariables(); + RETiRet; +} + + +BEGINmodInit() +CODESTARTmodInit + *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */ +CODEmodInit_QueryRegCFSLineHdlr + /* tell which objects we need */ + CHKiRet(objUse(errmsg, CORE_COMPONENT)); + + CHKiRet(omsdRegCFSLineHdlr( (uchar *)"actionmailsmtpserver", 0, eCmdHdlrGetWord, NULL, &pszSrv, STD_LOADABLE_MODULE_ID)); + CHKiRet(omsdRegCFSLineHdlr( (uchar *)"actionmailsmtpport", 0, eCmdHdlrGetWord, NULL, &pszSrvPort, STD_LOADABLE_MODULE_ID)); + CHKiRet(omsdRegCFSLineHdlr( (uchar *)"actionmailfrom", 0, eCmdHdlrGetWord, NULL, &pszFrom, STD_LOADABLE_MODULE_ID)); + CHKiRet(omsdRegCFSLineHdlr( (uchar *)"actionmailto", 0, eCmdHdlrGetWord, NULL, &pszTo, STD_LOADABLE_MODULE_ID)); + CHKiRet(omsdRegCFSLineHdlr( (uchar *)"actionmailsubject", 0, eCmdHdlrGetWord, NULL, &pszSubject, STD_LOADABLE_MODULE_ID)); + CHKiRet(omsdRegCFSLineHdlr( (uchar *)"actionmailenablebody", 0, eCmdHdlrBinary, NULL, &bEnableBody, STD_LOADABLE_MODULE_ID)); + CHKiRet(omsdRegCFSLineHdlr( (uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler, resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID)); +ENDmodInit + +/* vim:set ai: + */ |