diff options
Diffstat (limited to 'runtime/nsd_ptcp.c')
| -rw-r--r-- | runtime/nsd_ptcp.c | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/runtime/nsd_ptcp.c b/runtime/nsd_ptcp.c new file mode 100644 index 00000000..98de5802 --- /dev/null +++ b/runtime/nsd_ptcp.c @@ -0,0 +1,579 @@ +/* nsd_ptcp.c + * + * An implementation of the nsd interface for plain tcp sockets. + * + * Copyright 2007, 2008 Rainer Gerhards and Adiscon GmbH. + * + * This file is part of the rsyslog runtime library. + * + * The rsyslog runtime library is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * The rsyslog runtime library 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 Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with the rsyslog runtime library. If not, see <http://www.gnu.org/licenses/>. + * + * A copy of the GPL can be found in the file "COPYING" in this distribution. + * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution. + */ +#include "config.h" + +#include "rsyslog.h" +#include <stdio.h> +#include <stdarg.h> +#include <stdlib.h> +#include <assert.h> +#include <errno.h> +#include <string.h> +#include <signal.h> +#include <ctype.h> +#include <netdb.h> +#include <fnmatch.h> +#include <fcntl.h> +#include <unistd.h> + +#include "syslogd-types.h" +#include "module-template.h" +#include "parse.h" +#include "srUtils.h" +#include "obj.h" +#include "errmsg.h" +#include "net.h" +#include "nsd_ptcp.h" + +MODULE_TYPE_LIB + +/* static data */ +DEFobjStaticHelpers +DEFobjCurrIf(errmsg) +DEFobjCurrIf(glbl) +DEFobjCurrIf(net) + + +/* Standard-Constructor + */ +BEGINobjConstruct(nsd_ptcp) /* be sure to specify the object type also in END macro! */ + pThis->sock = -1; + pThis->iSessMax = 500; /* default max nbr of sessions -TODO:make configurable--rgerhards, 2008-04-17*/ +ENDobjConstruct(nsd_ptcp) + + +/* destructor for the nsd_ptcp object */ +BEGINobjDestruct(nsd_ptcp) /* be sure to specify the object type also in END and CODESTART macros! */ + int i; +CODESTARTobjDestruct(nsd_pctp) + if(pThis->sock != -1) { + close(pThis->sock); + pThis->sock = -1; + } + + if(pThis->socks != NULL) { + /* if we have some sockets at this stage, we need to close them */ + for(i = 1 ; i <= pThis->socks[0] ; ++i) + close(pThis->socks[i]); + free(pThis->socks); + } + + if(pThis->pRemHostIP != NULL) + free(pThis->pRemHostIP); + if(pThis->pRemHostName != NULL) + free(pThis->pRemHostName); +ENDobjDestruct(nsd_ptcp) + + +/* abort a connection. This is meant to be called immediately + * before the Destruct call. -- rgerhards, 2008-03-24 + */ +static rsRetVal +Abort(nsd_t *pNsd) +{ + struct linger ling; + nsd_ptcp_t *pThis = (nsd_ptcp_t*) pNsd; + + DEFiRet; + ISOBJ_TYPE_assert((pThis), nsd_ptcp); + + if((pThis)->sock != -1) { + ling.l_onoff = 1; + ling.l_linger = 0; + if(setsockopt((pThis)->sock, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling)) < 0 ) { + dbgprintf("could not set SO_LINGER, errno %d\n", errno); + } + } + + RETiRet; +} + + +/* Set pRemHost based on the address provided. This is to be called upon accept()ing + * a connection request. It must be provided by the socket we received the + * message on as well as a NI_MAXHOST size large character buffer for the FQDN. + * Please see http://www.hmug.org/man/3/getnameinfo.php (under Caveats) + * for some explanation of the code found below. If we detect a malicious + * hostname, we return RS_RET_MALICIOUS_HNAME and let the caller decide + * on how to deal with that. + * rgerhards, 2008-03-31 + */ +static rsRetVal +FillRemHost(nsd_ptcp_t *pThis, struct sockaddr *pAddr) +{ + int error; + uchar szIP[NI_MAXHOST] = ""; + uchar szHname[NI_MAXHOST] = ""; + struct addrinfo hints, *res; + size_t len; + + DEFiRet; + ISOBJ_TYPE_assert(pThis, nsd_ptcp); + assert(pAddr != NULL); + + error = getnameinfo(pAddr, SALEN(pAddr), (char*)szIP, sizeof(szIP), NULL, 0, NI_NUMERICHOST); + + if(error) { + dbgprintf("Malformed from address %s\n", gai_strerror(error)); + strcpy((char*)szHname, "???"); + strcpy((char*)szIP, "???"); + ABORT_FINALIZE(RS_RET_INVALID_HNAME); + } + + if(!glbl.GetDisableDNS()) { + error = getnameinfo(pAddr, SALEN(pAddr), (char*)szHname, NI_MAXHOST, NULL, 0, NI_NAMEREQD); + if(error == 0) { + memset (&hints, 0, sizeof (struct addrinfo)); + hints.ai_flags = AI_NUMERICHOST; + hints.ai_socktype = SOCK_STREAM; + /* we now do a lookup once again. This one should fail, + * because we should not have obtained a non-numeric address. If + * we got a numeric one, someone messed with DNS! + */ + if(getaddrinfo((char*)szHname, NULL, &hints, &res) == 0) { + freeaddrinfo (res); + /* OK, we know we have evil, so let's indicate this to our caller */ + snprintf((char*)szHname, NI_MAXHOST, "[MALICIOUS:IP=%s]", szIP); + dbgprintf("Malicious PTR record, IP = \"%s\" HOST = \"%s\"", szIP, szHname); + iRet = RS_RET_MALICIOUS_HNAME; + } + } else { + strcpy((char*)szHname, (char*)szIP); + } + } else { + strcpy((char*)szHname, (char*)szIP); + } + + /* We now have the names, so now let's allocate memory and store them permanently. + * (side note: we may hold on to these values for quite a while, thus we trim their + * memory consumption) + */ + len = strlen((char*)szIP) + 1; /* +1 for \0 byte */ + if((pThis->pRemHostIP = malloc(len)) == NULL) + ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY); + memcpy(pThis->pRemHostIP, szIP, len); + + len = strlen((char*)szHname) + 1; /* +1 for \0 byte */ + if((pThis->pRemHostName = malloc(len)) == NULL) { + free(pThis->pRemHostIP); /* prevent leak */ + pThis->pRemHostIP = NULL; + ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY); + } + memcpy(pThis->pRemHostName, szHname, len); + +finalize_it: + RETiRet; +} + + + +/* accept an incoming connection request, sock provides the socket on which we can + * accept the new session. + * rgerhards, 2008-03-17 + */ +static rsRetVal +AcceptConnReq(nsd_t **ppThis, int sock) +{ + int sockflags; + struct sockaddr_storage addr; + socklen_t addrlen = sizeof(addr); + nsd_ptcp_t *pThis = NULL; + int iNewSock = -1; + + DEFiRet; + assert(ppThis != NULL); + + iNewSock = accept(sock, (struct sockaddr*) &addr, &addrlen); + if(iNewSock < 0) { + ABORT_FINALIZE(RS_RET_ACCEPT_ERR); + } + + /* construct our object so that we can use it... */ + CHKiRet(nsd_ptcpConstruct(&pThis)); + + CHKiRet(FillRemHost(pThis, (struct sockaddr*) &addr)); + + /* set the new socket to non-blocking IO */ + if((sockflags = fcntl(iNewSock, F_GETFL)) != -1) { + sockflags |= O_NONBLOCK; + /* SETFL could fail too, so get it caught by the subsequent + * error check. + */ + sockflags = fcntl(iNewSock, F_SETFL, sockflags); + } + if(sockflags == -1) { + dbgprintf("error %d setting fcntl(O_NONBLOCK) on tcp socket %d", errno, iNewSock); + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + + pThis->sock = iNewSock; + + *ppThis = (nsd_t*) pThis; + +finalize_it: + if(iRet != RS_RET_OK) { + if(pThis != NULL) + nsd_ptcpDestruct(&pThis); + /* the close may be redundant, but that doesn't hurt... */ + if(iNewSock >= 0) + close(iNewSock); + } + + RETiRet; +} + + +/* initialize the tcp socket for a listner + * pLstnPort must point to a port name or number. NULL is NOT permitted + * (hint: we need to be careful when we use this module together with librelp, + * there NULL indicates the default port + * default is used. + * gerhards, 2008-03-17 + */ +static rsRetVal +LstnInit(nsd_t *pNsd, uchar *pLstnPort) +{ + nsd_ptcp_t *pThis = (nsd_ptcp_t*) pNsd; + struct addrinfo hints, *res, *r; + int error, maxs, *s, on = 1; + int sockflags; + + DEFiRet; + ISOBJ_TYPE_assert(pThis, nsd_ptcp); + assert(pLstnPort != NULL); + + dbgprintf("creating tcp listen socket on port %s\n", pLstnPort); + + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_PASSIVE; + hints.ai_family = glbl.GetDefPFFamily(); + hints.ai_socktype = SOCK_STREAM; + + error = getaddrinfo(NULL, (char*) pLstnPort, &hints, &res); + if(error) { + dbgprintf("error %d querying port '%s'\n", error, pLstnPort); + ABORT_FINALIZE(RS_RET_INVALID_PORT); + } + + /* Count max number of sockets we may open */ + for(maxs = 0, r = res; r != NULL ; r = r->ai_next, maxs++) + /* EMPTY */; + pThis->socks = malloc((maxs+1) * sizeof(int)); + if (pThis->socks == NULL) { + dbgprintf("couldn't allocate memory for TCP listen sockets, suspending RELP message reception."); + freeaddrinfo(res); + ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY); + } + + *pThis->socks = 0; /* num of sockets counter at start of array */ + s = pThis->socks + 1; + for(r = res; r != NULL ; r = r->ai_next) { + *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol); + if (*s < 0) { + if(!(r->ai_family == PF_INET6 && errno == EAFNOSUPPORT)) + dbgprintf("creating tcp listen socket"); + /* it is debatable if PF_INET with EAFNOSUPPORT should + * also be ignored... + */ + continue; + } + +#ifdef IPV6_V6ONLY + if (r->ai_family == AF_INET6) { + int iOn = 1; + if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY, + (char *)&iOn, sizeof (iOn)) < 0) { + close(*s); + *s = -1; + continue; + } + } +#endif + if(setsockopt(*s, SOL_SOCKET, SO_REUSEADDR, (char *) &on, sizeof(on)) < 0 ) { + dbgprintf("error %d setting tcp socket option\n", errno); + close(*s); + *s = -1; + continue; + } + + /* We use non-blocking IO! */ + if((sockflags = fcntl(*s, F_GETFL)) != -1) { + sockflags |= O_NONBLOCK; + /* SETFL could fail too, so get it caught by the subsequent + * error check. + */ + sockflags = fcntl(*s, F_SETFL, sockflags); + } + if(sockflags == -1) { + dbgprintf("error %d setting fcntl(O_NONBLOCK) on tcp socket", errno); + close(*s); + *s = -1; + continue; + } + + + + /* We need to enable BSD compatibility. Otherwise an attacker + * could flood our log files by sending us tons of ICMP errors. + */ +#ifndef BSD + if(net.should_use_so_bsdcompat()) { + if (setsockopt(*s, SOL_SOCKET, SO_BSDCOMPAT, + (char *) &on, sizeof(on)) < 0) { + errmsg.LogError(NO_ERRCODE, "TCP setsockopt(BSDCOMPAT)"); + close(*s); + *s = -1; + continue; + } + } +#endif + + if( (bind(*s, r->ai_addr, r->ai_addrlen) < 0) +#ifndef IPV6_V6ONLY + && (errno != EADDRINUSE) +#endif + ) { + dbgprintf("error %d while binding tcp socket", errno); + close(*s); + *s = -1; + continue; + } + + if(listen(*s,pThis->iSessMax / 10 + 5) < 0) { + /* If the listen fails, it most probably fails because we ask + * for a too-large backlog. So in this case we first set back + * to a fixed, reasonable, limit that should work. Only if + * that fails, too, we give up. + */ + dbgprintf("listen with a backlog of %d failed - retrying with default of 32.", + pThis->iSessMax / 10 + 5); + if(listen(*s, 32) < 0) { + dbgprintf("tcp listen error %d, suspending\n", errno); + close(*s); + *s = -1; + continue; + } + } + + (*pThis->socks)++; + s++; + } + + if(res != NULL) + freeaddrinfo(res); + + if(*pThis->socks != maxs) + dbgprintf("We could initialize %d RELP TCP listen sockets out of %d we received " + "- this may or may not be an error indication.\n", *pThis->socks, maxs); + + if(*pThis->socks == 0) { + dbgprintf("No RELP TCP listen socket could successfully be initialized, " + "message reception via RELP disabled.\n"); + free(pThis->socks); + ABORT_FINALIZE(RS_RET_COULD_NOT_BIND); + } + +finalize_it: + RETiRet; +} + + +/* receive data from a tcp socket + * The lenBuf parameter must contain the max buffer size on entry and contains + * the number of octets read (or -1 in case of error) on exit. This function + * never blocks, not even when called on a blocking socket. That is important + * for client sockets, which are set to block during send, but should not + * block when trying to read data. If *pLenBuf is -1, an error occured and + * errno holds the exact error cause. + * rgerhards, 2008-03-17 + */ +static rsRetVal +Rcv(nsd_t *pNsd, uchar *pRcvBuf, ssize_t *pLenBuf) +{ + DEFiRet; + nsd_ptcp_t *pThis = (nsd_ptcp_t*) pNsd; + ISOBJ_TYPE_assert(pThis, nsd_ptcp); + + *pLenBuf = recv(pThis->sock, pRcvBuf, *pLenBuf, MSG_DONTWAIT); + + RETiRet; +} + + +/* send a buffer. On entry, pLenBuf contains the number of octets to + * write. On exit, it contains the number of octets actually written. + * If this number is lower than on entry, only a partial buffer has + * been written. + * rgerhards, 2008-03-19 + */ +static rsRetVal +Send(nsd_t *pNsd, uchar *pBuf, ssize_t *pLenBuf) +{ + nsd_ptcp_t *pThis = (nsd_ptcp_t*) pNsd; + ssize_t written; + DEFiRet; + ISOBJ_TYPE_assert(pThis, nsd_ptcp); + + written = send(pThis->sock, pBuf, *pLenBuf, 0); + + if(written == -1) { + switch(errno) { + case EAGAIN: + case EINTR: + /* this is fine, just retry... */ + written = 0; + break; + default: + ABORT_FINALIZE(RS_RET_IO_ERROR); + break; + } + } + + *pLenBuf = written; +finalize_it: + RETiRet; +} + + +/* open a connection to a remote host (server). + * rgerhards, 2008-03-19 + */ +static rsRetVal +Connect(nsd_t *pNsd, int family, uchar *port, uchar *host) +{ + nsd_ptcp_t *pThis = (nsd_ptcp_t*) pNsd; + struct addrinfo *res = NULL; + struct addrinfo hints; + + DEFiRet; + ISOBJ_TYPE_assert(pThis, nsd_ptcp); + assert(port != NULL); + assert(host != NULL); + assert(pThis->sock == -1); + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = family; + hints.ai_socktype = SOCK_STREAM; + if(getaddrinfo((char*)host, (char*)port, &hints, &res) != 0) { + dbgprintf("error %d in getaddrinfo\n", errno); + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + + if((pThis->sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1) { + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + + if(connect(pThis->sock, res->ai_addr, res->ai_addrlen) != 0) { + ABORT_FINALIZE(RS_RET_IO_ERROR); + } + +finalize_it: + if(res != NULL) + freeaddrinfo(res); + + if(iRet != RS_RET_OK) { + if(pThis->sock != -1) { + close(pThis->sock); + pThis->sock = -1; + } + } + + RETiRet; +} + + +/* queryInterface function */ +BEGINobjQueryInterface(nsd_ptcp) +CODESTARTobjQueryInterface(nsd_ptcp) + if(pIf->ifVersion != nsdCURR_IF_VERSION) {/* check for current version, increment on each change */ + ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED); + } + + /* ok, we have the right interface, so let's fill it + * Please note that we may also do some backwards-compatibility + * work here (if we can support an older interface version - that, + * of course, also affects the "if" above). + */ + pIf->Construct = (rsRetVal(*)(nsd_t**)) nsd_ptcpConstruct; + pIf->Destruct = (rsRetVal(*)(nsd_t**)) nsd_ptcpDestruct; + pIf->Abort = Abort; + pIf->LstnInit = LstnInit; + pIf->AcceptConnReq = AcceptConnReq; + pIf->Rcv = Rcv; + pIf->Send = Send; + pIf->Connect = Connect; +finalize_it: +ENDobjQueryInterface(nsd_ptcp) + + +/* exit our class + */ +BEGINObjClassExit(nsd_ptcp, OBJ_IS_LOADABLE_MODULE) /* CHANGE class also in END MACRO! */ +CODESTARTObjClassExit(nsd_ptcp) + /* release objects we no longer need */ + objRelease(net, CORE_COMPONENT); + objRelease(glbl, CORE_COMPONENT); + objRelease(errmsg, CORE_COMPONENT); +ENDObjClassExit(nsd_ptcp) + + +/* Initialize the nsd_ptcp class. Must be called as the very first method + * before anything else is called inside this class. + * rgerhards, 2008-02-19 + */ +BEGINObjClassInit(nsd_ptcp, 1, OBJ_IS_LOADABLE_MODULE) /* class, version */ + /* request objects we use */ + CHKiRet(objUse(errmsg, CORE_COMPONENT)); + CHKiRet(objUse(glbl, CORE_COMPONENT)); + CHKiRet(objUse(net, CORE_COMPONENT)); + + /* set our own handlers */ +ENDObjClassInit(nsd_ptcp) + + +/* --------------- here now comes the plumbing that makes as a library module --------------- */ + + +BEGINmodExit +CODESTARTmodExit + nsd_ptcpClassExit(); +ENDmodExit + + +BEGINqueryEtryPt +CODESTARTqueryEtryPt +CODEqueryEtryPt_STD_LIB_QUERIES +ENDqueryEtryPt + + +BEGINmodInit() +CODESTARTmodInit + *ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */ + + /* Initialize all classes that are in our module - this includes ourselfs */ + CHKiRet(nsd_ptcpClassInit(pModInfo)); /* must be done after tcps_sess, as we use it */ +ENDmodInit +/* vi:set ai: + */ |