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SMTPSvr.cpp
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SMTPSvr.cpp
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/*
* XMail by Davide Libenzi (Intranet and Internet mail server)
* Copyright (C) 1999,..,2010 Davide Libenzi
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Davide Libenzi <[email protected]>
*
*/
#include "SysInclude.h"
#include "SysDep.h"
#include "SvrDefines.h"
#include "SList.h"
#include "ShBlocks.h"
#include "BuffSock.h"
#include "SSLBind.h"
#include "ResLocks.h"
#include "StrUtils.h"
#include "UsrUtils.h"
#include "SvrUtils.h"
#include "MessQueue.h"
#include "SMAILUtils.h"
#include "QueueUtils.h"
#include "MiscUtils.h"
#include "SSLConfig.h"
#include "Base64Enc.h"
#include "MD5.h"
#include "UsrMailList.h"
#include "SMTPSvr.h"
#include "SMTPUtils.h"
#include "MailDomains.h"
#include "AliasDomain.h"
#include "POP3Utils.h"
#include "Filter.h"
#include "MailConfig.h"
#include "AppDefines.h"
#include "MailSvr.h"
#define SMTP_MAX_LINE_SIZE 2048
#define STD_SMTP_TIMEOUT 30000
#define SMTP_IPMAP_FILE "smtp.ipmap.tab"
#define SMTP_LOG_FILE "smtp"
#define SMTP_POST_RCPT_FILTER "post-rcpt"
#define SMTP_PRE_DATA_FILTER "pre-data"
#define SMTP_POST_DATA_FILTER "post-data"
#define SMTP_FILTER_REJECT_CODE 3
#define PLAIN_AUTH_PARAM_SIZE 1024
#define LOGIN_AUTH_USERNAME "Username:"
#define LOGIN_AUTH_PASSWORD "Password:"
#define SVR_SMTP_AUTH_FILE "smtpauth.tab"
#define SVR_SMTPAUTH_LINE_MAX 512
#define SVR_SMTP_EXTAUTH_FILE "smtpextauth.tab"
#define SVR_SMTP_EXTAUTH_LINE_MAX 1024
#define SVR_SMTP_EXTAUTH_TIMEOUT 60000
#define SVR_SMTP_EXTAUTH_SUCCESS 0
#define SMTPF_RELAY_ENABLED (1 << 0)
#define SMTPF_MAIL_LOCKED (1 << 1)
#define SMTPF_MAIL_UNLOCKED (1 << 2)
#define SMTPF_AUTHENTICATED (1 << 3)
#define SMTPF_VRFY_ENABLED (1 << 4)
#define SMTPF_MAPPED_IP (1 << 5)
#define SMTPF_NORDNS_IP (1 << 6)
#define SMTPF_ETRN_ENABLED (1 << 7)
#define SMTPF_NOEMIT_AUTH (1 << 8)
#define SMTPF_WHITE_LISTED (1 << 9)
#define SMTPF_BLOCKED_IP (1 << 10)
#define SMTPF_IPMAPPED_IP (1 << 11)
#define SMTPF_SNDRCHECK_BYPASS (1 << 12)
#define SMTPF_WANT_TLS (1 << 13)
#define SMTPF_EASE_TLS (1 << 14)
#define SMTPF_STATIC_MASK (SMTPF_MAPPED_IP | SMTPF_NORDNS_IP | SMTPF_WHITE_LISTED | \
SMTPF_SNDRCHECK_BYPASS | SMTPF_BLOCKED_IP | SMTPF_IPMAPPED_IP)
#define SMTPF_AUTH_MASK (SMTPF_RELAY_ENABLED | SMTPF_MAIL_UNLOCKED | SMTPF_AUTHENTICATED | \
SMTPF_VRFY_ENABLED | SMTPF_ETRN_ENABLED | SMTPF_EASE_TLS)
#define SMTPF_RESET_MASK (SMTPF_AUTH_MASK | SMTPF_STATIC_MASK)
#define SMTP_FILTER_FL_BREAK (1 << 4)
#define SMTP_FILTER_FL_MASK SMTP_FILTER_FL_BREAK
enum SMTPStates {
stateInit = 0,
stateHelo,
stateAuthenticated,
stateMail,
stateRcpt,
stateExit
};
struct SMTPSession {
int iSMTPState;
ThreadConfig const *pThCfg;
SMTPConfig *pSMTPCfg;
SVRCFG_HANDLE hSvrConfig;
SYS_INET_ADDR PeerInfo;
SYS_INET_ADDR SockInfo;
int iCmdDelay;
unsigned long ulMaxMsgSize;
char szSvrFQDN[MAX_ADDR_NAME];
char szSvrDomain[MAX_ADDR_NAME];
char szClientFQDN[MAX_ADDR_NAME];
char szClientDomain[MAX_ADDR_NAME];
char szDestDomain[MAX_ADDR_NAME];
char szLogonUser[128];
char szMsgFile[SYS_MAX_PATH];
FILE *pMsgFile;
char *pszFrom;
char *pszRcpt;
char *pszSendRcpt;
char *pszRealRcpt;
int iRcptCount;
int iErrorsCount;
int iErrorsMax;
SYS_UINT64 ullMessageID;
char szMessageID[128];
char szTimeStamp[256];
unsigned long ulSetupFlags;
unsigned long ulFlags;
char *pszCustMsg;
char szRejMapName[256];
char *pszNoTLSAuths;
};
enum SmtpAuthFields {
smtpaUsername = 0,
smtpaPassword,
smtpaPerms,
smtpaMax
};
struct ExtAuthMacroSubstCtx {
char const *pszAuthType;
char const *pszUsername;
char const *pszPassword;
char const *pszChallenge;
char const *pszDigest;
char const *pszRespFile;
};
static int SMTPLogEnabled(SHB_HANDLE hShbSMTP, SMTPConfig *pSMTPCfg = NULL);
static int SMTPThreadCountAdd(long lCount, SHB_HANDLE hShbSMTP, SMTPConfig *pSMTPCfg = NULL);
static char const *SMTPGetFilterExtname(char const *pszFiltID)
{
static struct Filter_ID_Name {
char const *pszFiltID;
char const *pszName;
} const FiltIdNames[] = {
{ SMTP_POST_RCPT_FILTER, "RCPT" },
{ SMTP_PRE_DATA_FILTER, "PREDATA" },
{ SMTP_POST_DATA_FILTER, "POSTDATA" },
};
int i;
for (i = 0; i < CountOf(FiltIdNames); i++)
if (strcmp(FiltIdNames[i].pszFiltID, pszFiltID) == 0)
return FiltIdNames[i].pszName;
return "UNKNOWN";
}
static SMTPConfig *SMTPGetConfigCopy(SHB_HANDLE hShbSMTP)
{
SMTPConfig *pSMTPCfg = (SMTPConfig *) ShbLock(hShbSMTP);
if (pSMTPCfg == NULL)
return NULL;
SMTPConfig *pSMTPCfgCopy = (SMTPConfig *) SysAlloc(sizeof(SMTPConfig));
if (pSMTPCfgCopy != NULL)
memcpy(pSMTPCfgCopy, pSMTPCfg, sizeof(SMTPConfig));
ShbUnlock(hShbSMTP);
return pSMTPCfgCopy;
}
static int SMTPLogEnabled(SHB_HANDLE hShbSMTP, SMTPConfig *pSMTPCfg)
{
int iDoUnlock = 0;
if (pSMTPCfg == NULL) {
if ((pSMTPCfg = (SMTPConfig *) ShbLock(hShbSMTP)) == NULL)
return ErrGetErrorCode();
++iDoUnlock;
}
unsigned long ulFlags = pSMTPCfg->ulFlags;
if (iDoUnlock)
ShbUnlock(hShbSMTP);
return (ulFlags & SMTPF_LOG_ENABLED) ? 1 : 0;
}
static int SMTPCheckPeerIP(const SYS_INET_ADDR &PeerAddr)
{
char szIPMapFile[SYS_MAX_PATH] = "";
CfgGetRootPath(szIPMapFile, sizeof(szIPMapFile));
StrNCat(szIPMapFile, SMTP_IPMAP_FILE, sizeof(szIPMapFile));
if (SysExistFile(szIPMapFile) &&
MscCheckAllowedIP(szIPMapFile, PeerAddr, true) < 0)
return ErrGetErrorCode();
return 0;
}
static int SMTPThreadCountAdd(long lCount, SHB_HANDLE hShbSMTP, SMTPConfig *pSMTPCfg)
{
int iDoUnlock = 0;
if (pSMTPCfg == NULL) {
if ((pSMTPCfg = (SMTPConfig *) ShbLock(hShbSMTP)) == NULL)
return ErrGetErrorCode();
++iDoUnlock;
}
if ((pSMTPCfg->lThreadCount + lCount) > pSMTPCfg->lMaxThreads) {
if (iDoUnlock)
ShbUnlock(hShbSMTP);
ErrSetErrorCode(ERR_SERVER_BUSY);
return ERR_SERVER_BUSY;
}
pSMTPCfg->lThreadCount += lCount;
if (iDoUnlock)
ShbUnlock(hShbSMTP);
return 0;
}
static int SMTPCheckSysResources(SVRCFG_HANDLE hSvrConfig)
{
/* Check disk space */
int iMinValue = SvrGetConfigInt("SmtpMinDiskSpace", -1, hSvrConfig);
if ((iMinValue > 0) && (SvrCheckDiskSpace(1024 * (unsigned long) iMinValue) < 0))
return ErrGetErrorCode();
/* Check virtual memory */
if (((iMinValue = SvrGetConfigInt("SmtpMinVirtMemSpace", -1, hSvrConfig)) > 0) &&
(SvrCheckVirtMemSpace(1024 * (unsigned long) iMinValue) < 0))
return ErrGetErrorCode();
return 0;
}
static int SMTPEnumIPPropsCB(void *pPrivate, char const *pszName, char const *pszVal)
{
SMTPSession *pSMTPS = (SMTPSession *) pPrivate;
if (strcmp(pszName, "WhiteList") == 0) {
if (pszVal == NULL || atoi(pszVal))
pSMTPS->ulFlags |= SMTPF_WHITE_LISTED;
} else if (strcmp(pszName, "NoAuth") == 0) {
if (pszVal == NULL || atoi(pszVal))
pSMTPS->ulFlags |= SMTPF_MAIL_UNLOCKED;
} else if (strcmp(pszName, "SenderDomainCheck") == 0) {
if (pszVal != NULL && !atoi(pszVal))
pSMTPS->ulFlags |= SMTPF_SNDRCHECK_BYPASS;
} else if (strcmp(pszName, "EaseTLS") == 0) {
if (pszVal == NULL || atoi(pszVal))
pSMTPS->ulSetupFlags &= ~SMTPF_WANT_TLS;
} else if (strcmp(pszName, "EnableVRFY") == 0) {
if (pszVal == NULL || atoi(pszVal))
pSMTPS->ulFlags |= SMTPF_VRFY_ENABLED;
} else if (strcmp(pszName, "EnableETRN") == 0) {
if (pszVal == NULL || atoi(pszVal))
pSMTPS->ulFlags |= SMTPF_ETRN_ENABLED;
}
return 0;
}
static int SMTPApplyIPProps(SMTPSession &SMTPS)
{
return SvrEnumProtoProps("smtp", &SMTPS.PeerInfo,
IsEmptyString(SMTPS.szClientFQDN) ? NULL: SMTPS.szClientFQDN,
SMTPEnumIPPropsCB, &SMTPS);
}
static int SMTPLogSession(SMTPSession &SMTPS, char const *pszSender,
char const *pszRecipient, char const *pszStatus,
unsigned long ulMsgSize)
{
char szTime[256] = "";
MscGetTimeNbrString(szTime, sizeof(szTime) - 1);
RLCK_HANDLE hResLock = RLckLockEX(SVR_LOGS_DIR SYS_SLASH_STR SMTP_LOG_FILE);
if (hResLock == INVALID_RLCK_HANDLE)
return ErrGetErrorCode();
char szIP[128] = "???.???.???.???";
MscFileLog(SMTP_LOG_FILE, "\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%s\""
"\t\"%lu\""
"\t\"%s\""
"\n", SMTPS.szSvrFQDN, SMTPS.szSvrDomain,
SysInetNToA(SMTPS.PeerInfo, szIP, sizeof(szIP)), szTime,
SMTPS.szClientDomain, SMTPS.szDestDomain, pszSender, pszRecipient,
SMTPS.szMessageID, pszStatus, SMTPS.szLogonUser, ulMsgSize,
SMTPS.szClientFQDN);
RLckUnlockEX(hResLock);
return 0;
}
static int SMTPCheckMapsList(SYS_INET_ADDR const &PeerInfo, char const *pszMapList,
char *pszMapName, int iMaxMapName, int &iMapCode)
{
for (;;) {
char const *pszColon = strchr(pszMapList, ':');
if (pszColon == NULL)
break;
int iRetCode = atoi(pszColon + 1);
int iMapLength = Min((int) (pszColon - pszMapList), MAX_HOST_NAME - 1);
char szMapName[MAX_HOST_NAME] = "";
strncpy(szMapName, pszMapList, iMapLength);
szMapName[iMapLength] = '\0';
if (USmtpDnsMapsContained(PeerInfo, szMapName)) {
char szIP[128] = "???.???.???.???";
char szMapSpec[MAX_HOST_NAME + 128] = "";
if (pszMapName != NULL)
StrNCpy(pszMapName, szMapName, iMaxMapName);
iMapCode = iRetCode;
SysInetNToA(PeerInfo, szIP, sizeof(szIP));
SysSNPrintf(szMapSpec, sizeof(szMapSpec) - 1, "%s:%s",
szMapName, szIP);
ErrSetErrorCode(ERR_MAPS_CONTAINED, szMapSpec);
return ERR_MAPS_CONTAINED;
}
if ((pszMapList = strchr(pszColon, ',')) == NULL)
break;
++pszMapList;
}
return 0;
}
static int SMTPDoIPBasedInit(SMTPSession &SMTPS, char *&pszSMTPError)
{
int iErrorCode;
/* Check using the "smtp.ipmap.tab" file */
if ((iErrorCode = SMTPCheckPeerIP(SMTPS.PeerInfo)) < 0) {
int iMapCode = SvrGetConfigInt("SMTP-IpMapDropCode", 1, SMTPS.hSvrConfig);
if (iMapCode > 0) {
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS, "", "", "SNDRIP=EIPBAN", 0);
pszSMTPError = SvrGetConfigVar(SMTPS.hSvrConfig, "SmtpMsgIPBan");
ErrSetErrorCode(iErrorCode);
return iErrorCode;
} else if (iMapCode == 0) {
SMTPS.ulFlags |= SMTPF_IPMAPPED_IP;
} else
SMTPS.iCmdDelay = Max(SMTPS.iCmdDelay, Abs(iMapCode));
}
/* Check if SMTP client is in "spammers.tab" file */
char *pszChkInfo = NULL;
if ((iErrorCode = USmtpSpammerCheck(SMTPS.PeerInfo, pszChkInfo)) < 0) {
int iMapCode = 1;
if (pszChkInfo != NULL) {
char szMapCode[32] = "";
if (StrParamGet(pszChkInfo, "code", szMapCode, sizeof(szMapCode) - 1))
iMapCode = atoi(szMapCode);
SysFree(pszChkInfo);
}
if (iMapCode > 0) {
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS, "", "", "SNDRIP=EIPSPAM", 0);
pszSMTPError = SvrGetConfigVar(SMTPS.hSvrConfig, "SmtpMsgIPBanSpammers");
ErrSetErrorCode(iErrorCode);
return iErrorCode;
} else if (iMapCode == 0) {
SMTPS.ulFlags |= SMTPF_BLOCKED_IP;
} else
SMTPS.iCmdDelay = Max(SMTPS.iCmdDelay, Abs(iMapCode));
}
/* Custom maps checking */
char *pszMapsList = SvrGetConfigVar(SMTPS.hSvrConfig, "CustMapsList");
if (pszMapsList != NULL) {
int iMapCode = 0;
char *pszCfgError = NULL;
if (SMTPCheckMapsList(SMTPS.PeerInfo, pszMapsList, SMTPS.szRejMapName,
sizeof(SMTPS.szRejMapName) - 1, iMapCode) < 0) {
if (iMapCode == 1) {
ErrorPush();
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg)) {
char *pszError =
StrSprint("SNDRIP=EIPMAP (%s)", SMTPS.szRejMapName);
SMTPLogSession(SMTPS, "", "",
(pszError !=
NULL) ? pszError : "SNDRIP=EIPMAP", 0);
SysFree(pszError);
}
if ((pszCfgError =
SvrGetConfigVar(SMTPS.hSvrConfig,
"SmtpMsgIPBanMaps")) != NULL) {
pszSMTPError =
StrSprint("%s (%s)", pszCfgError, SMTPS.szRejMapName);
SysFree(pszCfgError);
} else
pszSMTPError =
StrSprint
("550 Denied due inclusion of your IP inside (%s)",
SMTPS.szRejMapName);
SysFree(pszMapsList);
return ErrorPop();
}
if (iMapCode == 0)
SMTPS.ulFlags |= SMTPF_MAPPED_IP;
else
SMTPS.iCmdDelay = Max(SMTPS.iCmdDelay, Abs(iMapCode));
}
SysFree(pszMapsList);
}
/* RDNS client check */
int iCheckValue = SvrGetConfigInt("SMTP-RDNSCheck", 0, SMTPS.hSvrConfig);
if (iCheckValue != 0 &&
SysGetHostByAddr(SMTPS.PeerInfo, SMTPS.szClientFQDN, sizeof(SMTPS.szClientFQDN)) < 0) {
if (iCheckValue > 0)
SMTPS.ulFlags |= SMTPF_NORDNS_IP;
else
SMTPS.iCmdDelay = Max(SMTPS.iCmdDelay, -iCheckValue);
}
return 0;
}
static int SMTPSvrCfgOptionsAssign(void *pPrivate, char const *pszName, char const *pszValue)
{
SMTPSession *pSMTPS = (SMTPSession *) pPrivate;
if (strcmp(pszName, "mail-auth") == 0 ||
strcmp(pszName, "MailAuth") == 0) {
if (pszValue == NULL || atoi(pszValue))
pSMTPS->ulSetupFlags |= SMTPF_MAIL_LOCKED;
} else if (strcmp(pszName, "WantTLS") == 0) {
if (pszValue == NULL || atoi(pszValue))
pSMTPS->ulSetupFlags |= SMTPF_WANT_TLS;
}
return 0;
}
static int SMTPLoadConfig(SMTPSession &SMTPS, char const *pszSvrConfig)
{
return MscParseOptions(pszSvrConfig, SMTPSvrCfgOptionsAssign, &SMTPS);
}
static int SMTPApplyPerms(SMTPSession &SMTPS, char const *pszPerms)
{
for (int i = 0; pszPerms[i] != '\0'; i++) {
switch (pszPerms[i]) {
case 'M':
SMTPS.ulFlags |= SMTPF_MAIL_UNLOCKED;
break;
case 'R':
SMTPS.ulFlags |= SMTPF_RELAY_ENABLED;
break;
case 'V':
SMTPS.ulFlags |= SMTPF_VRFY_ENABLED;
break;
case 'T':
SMTPS.ulFlags |= SMTPF_ETRN_ENABLED;
break;
case 'Z':
SMTPS.ulMaxMsgSize = 0;
break;
case 'S':
SMTPS.ulFlags |= SMTPF_EASE_TLS;
break;
}
}
/* Clear bad ip mask and command delay */
SMTPS.ulFlags &= ~(SMTPF_MAPPED_IP | SMTPF_NORDNS_IP | SMTPF_BLOCKED_IP | SMTPF_IPMAPPED_IP);
SMTPS.iCmdDelay = 0;
return 0;
}
static int SMTPInitSession(ThreadConfig const *pThCfg, BSOCK_HANDLE hBSock,
SMTPSession &SMTPS, char *&pszSMTPError)
{
ZeroData(SMTPS);
SMTPS.iSMTPState = stateInit;
SMTPS.pThCfg = pThCfg;
SMTPS.hSvrConfig = INVALID_SVRCFG_HANDLE;
SMTPS.pSMTPCfg = NULL;
SMTPS.pMsgFile = NULL;
SMTPS.pszFrom = NULL;
SMTPS.pszRcpt = NULL;
SMTPS.pszSendRcpt = NULL;
SMTPS.pszRealRcpt = NULL;
SMTPS.iRcptCount = 0;
SMTPS.iErrorsCount = 0;
SMTPS.iErrorsMax = 0;
SMTPS.iCmdDelay = 0;
SMTPS.ulMaxMsgSize = 0;
SetEmptyString(SMTPS.szMessageID);
SetEmptyString(SMTPS.szDestDomain);
SetEmptyString(SMTPS.szClientFQDN);
SetEmptyString(SMTPS.szClientDomain);
SetEmptyString(SMTPS.szLogonUser);
SetEmptyString(SMTPS.szRejMapName);
SMTPS.ulFlags = 0;
SMTPS.ulSetupFlags = 0;
SMTPS.pszCustMsg = NULL;
SMTPS.pszNoTLSAuths = NULL;
MscSafeGetTmpFile(SMTPS.szMsgFile, sizeof(SMTPS.szMsgFile));
if ((SMTPS.hSvrConfig = SvrGetConfigHandle()) == INVALID_SVRCFG_HANDLE)
return ErrGetErrorCode();
if (SMTPCheckSysResources(SMTPS.hSvrConfig) < 0 ||
SysGetPeerInfo(BSckGetAttachedSocket(hBSock), SMTPS.PeerInfo) < 0 ||
SysGetSockInfo(BSckGetAttachedSocket(hBSock), SMTPS.SockInfo) < 0 ||
SMTPApplyIPProps(SMTPS) < 0) {
ErrorPush();
SvrReleaseConfigHandle(SMTPS.hSvrConfig);
return ErrorPop();
}
/* If the remote IP is not white-listed, do all IP based checks */
if ((SMTPS.ulFlags & SMTPF_WHITE_LISTED) == 0 &&
SMTPDoIPBasedInit(SMTPS, pszSMTPError) < 0) {
ErrorPush();
SvrReleaseConfigHandle(SMTPS.hSvrConfig);
return ErrorPop();
}
/* Get maximum errors count allowed in an SMTP session */
SMTPS.iErrorsMax = SvrGetConfigInt("SMTP-MaxErrors", 0, SMTPS.hSvrConfig);
/* Setup SMTP domain */
char *pszSvrDomain = SvrGetConfigVar(SMTPS.hSvrConfig, "SmtpServerDomain");
char szIP[128] = "???.???.???.???";
if (pszSvrDomain != NULL) {
StrSNCpy(SMTPS.szSvrDomain, pszSvrDomain);
StrSNCpy(SMTPS.szSvrFQDN, pszSvrDomain);
SysFree(pszSvrDomain);
} else {
if (SysGetHostByAddr(SMTPS.SockInfo, SMTPS.szSvrFQDN, sizeof(SMTPS.szSvrFQDN)) < 0)
StrSNCpy(SMTPS.szSvrFQDN, SysInetNToA(SMTPS.SockInfo, szIP,
sizeof(szIP)));
else {
/* Try to get a valid domain from the FQDN */
if (MDomGetClientDomain(SMTPS.szSvrFQDN, SMTPS.szSvrDomain,
sizeof(SMTPS.szSvrDomain) - 1) < 0)
StrSNCpy(SMTPS.szSvrDomain, SMTPS.szSvrFQDN);
}
/* Last attempt, try fetch the "RootDomain" variable ... */
if (IsEmptyString(SMTPS.szSvrDomain)) {
if ((pszSvrDomain = SvrGetConfigVar(SMTPS.hSvrConfig,
"RootDomain")) == NULL) {
SvrReleaseConfigHandle(SMTPS.hSvrConfig);
ErrSetErrorCode(ERR_NO_DOMAIN);
return ERR_NO_DOMAIN;
}
StrSNCpy(SMTPS.szSvrDomain, pszSvrDomain);
SysFree(pszSvrDomain);
}
}
/* Create timestamp */
sprintf(SMTPS.szTimeStamp, "<%lu.%lu@%s>",
(unsigned long) time(NULL), SysGetCurrentThreadId(), SMTPS.szSvrDomain);
if ((SMTPS.pSMTPCfg = SMTPGetConfigCopy(hShbSMTP)) == NULL) {
ErrorPush();
SvrReleaseConfigHandle(SMTPS.hSvrConfig);
return ErrorPop();
}
/* Get maximum accepted message size */
SMTPS.ulMaxMsgSize = 1024 * (unsigned long) SvrGetConfigInt("MaxMessageSize",
0, SMTPS.hSvrConfig);
/* Check if the emission of "X-Auth-User:" is diabled */
if (SvrGetConfigInt("DisableEmitAuthUser", 0, SMTPS.hSvrConfig))
SMTPS.ulSetupFlags |= SMTPF_NOEMIT_AUTH;
/* Try to load specific configuration */
char szConfigName[128] = "";
SysInetNToA(SMTPS.SockInfo, szIP, sizeof(szIP));
SysSNPrintf(szConfigName, sizeof(szConfigName), "SmtpConfig-%s,%d",
szIP, SysGetAddrPort(SMTPS.SockInfo));
char *pszSvrConfig = SvrGetConfigVar(SMTPS.hSvrConfig, szConfigName);
if (pszSvrConfig == NULL) {
SysSNPrintf(szConfigName, sizeof(szConfigName), "SmtpConfig-%s", szIP);
if ((pszSvrConfig = SvrGetConfigVar(SMTPS.hSvrConfig, szConfigName)) == NULL)
pszSvrConfig = SvrGetConfigVar(SMTPS.hSvrConfig, "SmtpConfig");
}
if (pszSvrConfig != NULL) {
SMTPLoadConfig(SMTPS, pszSvrConfig);
SysFree(pszSvrConfig);
}
SMTPS.ulFlags |= SMTPS.ulSetupFlags;
/* Get custom message to append to the SMTP response */
SMTPS.pszCustMsg = SvrGetConfigVar(SMTPS.hSvrConfig, "CustomSMTPMessage");
/* Get custom message to append to the SMTP response */
SMTPS.pszNoTLSAuths = SvrGetConfigVar(SMTPS.hSvrConfig, "SmtpNoTLSAuths");
return 0;
}
static void SMTPClearSession(SMTPSession &SMTPS)
{
if (SMTPS.pMsgFile != NULL)
fclose(SMTPS.pMsgFile), SMTPS.pMsgFile = NULL;
SysRemove(SMTPS.szMsgFile);
if (SMTPS.hSvrConfig != INVALID_SVRCFG_HANDLE)
SvrReleaseConfigHandle(SMTPS.hSvrConfig), SMTPS.hSvrConfig =
INVALID_SVRCFG_HANDLE;
SysFreeNullify(SMTPS.pSMTPCfg);
SysFreeNullify(SMTPS.pszFrom);
SysFreeNullify(SMTPS.pszRcpt);
SysFreeNullify(SMTPS.pszSendRcpt);
SysFreeNullify(SMTPS.pszRealRcpt);
SysFreeNullify(SMTPS.pszCustMsg);
SysFreeNullify(SMTPS.pszNoTLSAuths);
}
static void SMTPResetSession(SMTPSession &SMTPS)
{
SMTPS.ulFlags = SMTPS.ulSetupFlags | (SMTPS.ulFlags & SMTPF_RESET_MASK);
SMTPS.ullMessageID = 0;
SMTPS.iRcptCount = 0;
SetEmptyString(SMTPS.szMessageID);
if (SMTPS.pMsgFile != NULL)
fclose(SMTPS.pMsgFile), SMTPS.pMsgFile = NULL;
SysRemove(SMTPS.szMsgFile);
SetEmptyString(SMTPS.szDestDomain);
SysFreeNullify(SMTPS.pszFrom);
SysFreeNullify(SMTPS.pszRcpt);
SysFreeNullify(SMTPS.pszSendRcpt);
SysFreeNullify(SMTPS.pszRealRcpt);
SMTPS.iSMTPState = (SMTPS.ulFlags & SMTPF_AUTHENTICATED) ? stateAuthenticated:
Min(SMTPS.iSMTPState, stateHelo);
}
static void SMTPFullResetSession(SMTPSession &SMTPS)
{
SMTPS.ulFlags = 0;
SMTPS.iSMTPState = stateInit;
SMTPResetSession(SMTPS);
}
static int SMTPGetUserSmtpPerms(UserInfo *pUI, SVRCFG_HANDLE hSvrConfig, char *pszPerms,
int iMaxPerms)
{
char *pszUserPerms = UsrGetUserInfoVar(pUI, "SmtpPerms");
if (pszUserPerms != NULL) {
StrNCpy(pszPerms, pszUserPerms, iMaxPerms);
SysFree(pszUserPerms);
} else {
/* Match found, get the default permissions */
char *pszDefultPerms = SvrGetConfigVar(hSvrConfig,
"DefaultSmtpPerms", "MRVZ");
if (pszDefultPerms != NULL) {
StrNCpy(pszPerms, pszDefultPerms, iMaxPerms);
SysFree(pszDefultPerms);
} else
SetEmptyString(pszPerms);
}
return 0;
}
static int SMTPApplyUserConfig(SMTPSession &SMTPS, UserInfo *pUI)
{
/* Retrieve and apply permissions */
char *pszValue = NULL;
char szPerms[128] = "";
if (SMTPGetUserSmtpPerms(pUI, SMTPS.hSvrConfig, szPerms, sizeof(szPerms) - 1) < 0)
return ErrGetErrorCode();
SMTPApplyPerms(SMTPS, szPerms);
/* Check "MaxMessageSize" override */
if ((pszValue = UsrGetUserInfoVar(pUI, "MaxMessageSize")) != NULL) {
SMTPS.ulMaxMsgSize = 1024 * (unsigned long) atol(pszValue);
SysFree(pszValue);
}
/* Check if the emission of "X-Auth-User:" is diabled */
if ((pszValue = UsrGetUserInfoVar(pUI, "DisableEmitAuthUser")) != NULL) {
if (atoi(pszValue))
SMTPS.ulFlags |= SMTPF_NOEMIT_AUTH;
else
SMTPS.ulFlags &= ~SMTPF_NOEMIT_AUTH;
SysFree(pszValue);
}
return 0;
}
static int SMTPSendError(BSOCK_HANDLE hBSock, SMTPSession &SMTPS, char const *pszFormat, ...)
{
char *pszBuffer = NULL;
StrVSprint(pszBuffer, pszFormat, pszFormat);
if (pszBuffer == NULL)
return ErrGetErrorCode();
if (SMTPS.pszCustMsg == NULL) {
if (BSckSendString(hBSock, pszBuffer, SMTPS.pSMTPCfg->iTimeout) < 0) {
ErrorPush();
SysFree(pszBuffer);
return ErrorPop();
}
} else {
if (BSckVSendString(hBSock, SMTPS.pSMTPCfg->iTimeout,
"%s - %s", pszBuffer, SMTPS.pszCustMsg) < 0) {
ErrorPush();
SysFree(pszBuffer);
return ErrorPop();
}
}
SysFree(pszBuffer);
/*
* Increase the number of errors we encountered in this session. If the
* maximum number of allowed errors is not zero, and the current number of
* errors exceed the maximum number, we set the state to 'exit' so that the
* SMTP connection will be dropped.
*/
SMTPS.iErrorsCount++;
if (SMTPS.iErrorsMax > 0 && SMTPS.iErrorsCount >= SMTPS.iErrorsMax) {
char szIP[128] = "";
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS, SMTPS.pszFrom != NULL ? SMTPS.pszFrom: "",
"", "SMTP=EERRS", 0);
SysLogMessage(LOG_LEV_MESSAGE, "SMTP forced exit (too many errors: %d) [%s]\n",
SMTPS.iErrorsCount, SysInetNToA(SMTPS.PeerInfo, szIP, sizeof(szIP)));
SMTPS.iSMTPState = stateExit;
}
return 0;
}
static int SMTPTryPopAuthIpCheck(SMTPSession &SMTPS, char const *pszUser, char const *pszDomain)
{
/* Load user info */
UserInfo *pUI = UsrGetUserByNameOrAlias(pszDomain, pszUser);
if (pUI == NULL)
return ErrGetErrorCode();
/* Perform IP file checking */
if (UPopUserIpCheck(pUI, &SMTPS.PeerInfo, SMTPS.pSMTPCfg->uPopAuthExpireTime) < 0) {
ErrorPush();
UsrFreeUserInfo(pUI);
return ErrorPop();
}
/* Apply user configuration */
if (SMTPApplyUserConfig(SMTPS, pUI) < 0) {
ErrorPush();
UsrFreeUserInfo(pUI);
return ErrorPop();
}
/* If the user did not authenticate, set the logon user token */
if (IsEmptyString(SMTPS.szLogonUser))
UsrGetAddress(pUI, SMTPS.szLogonUser);
UsrFreeUserInfo(pUI);
return 0;
}
static int SMTPCheckMailParams(char const *pszCommand, char **ppszRetDomains,
SMTPSession &SMTPS, char *&pszSMTPError)
{
char const *pszParams = strrchr(pszCommand, '>');
if (pszParams == NULL)
pszParams = pszCommand;
/* Check the SIZE parameter */
if (SMTPS.ulMaxMsgSize != 0) {
char const *pszSize = pszParams;
while ((pszSize = StrIStr(pszSize, " SIZE=")) != NULL) {
pszSize += CStringSize(" SIZE=");
if (isdigit(*pszSize) &&
SMTPS.ulMaxMsgSize < (unsigned long) atol(pszSize)) {
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS,
(ppszRetDomains[0] !=
NULL) ? ppszRetDomains[0] : "", "",
"SIZE=EBIG",
(unsigned long) atol(pszSize));
pszSMTPError =
SysStrDup("552 Message exceeds fixed maximum message size");
ErrSetErrorCode(ERR_MESSAGE_SIZE);
return ERR_MESSAGE_SIZE;
}
}
}
return 0;
}
static int SMTPCheckReturnPath(char const *pszCommand, char **ppszRetDomains,
SMTPSession &SMTPS, char *&pszSMTPError)
{
int iDomainCount;
char szMailerUser[MAX_ADDR_NAME] = "";
char szMailerDomain[MAX_ADDR_NAME] = "";
if ((iDomainCount = StrStringsCount(ppszRetDomains)) == 0) {
if (!SvrTestConfigFlag("AllowNullSender", true, SMTPS.hSvrConfig)) {
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS, "", "", "SNDR=EEMPTY", 0);
pszSMTPError = SysStrDup("501 Syntax error in return path");
ErrSetErrorCode(ERR_BAD_RETURN_PATH);
return ERR_BAD_RETURN_PATH;
}
SysFree(SMTPS.pszFrom);
SMTPS.pszFrom = SysStrDup("");
return 0;
}
if (USmtpSplitEmailAddr(ppszRetDomains[0], szMailerUser, szMailerDomain) < 0) {
ErrorPush();
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS, ppszRetDomains[0], "", "SNDR=ESYNTAX", 0);
pszSMTPError = SysStrDup("501 Syntax error in return path");
return ErrorPop();
}
/* Check mailer domain for DNS/MX entries */
if (!(SMTPS.ulFlags & SMTPF_SNDRCHECK_BYPASS) &&
SvrTestConfigFlag("CheckMailerDomain", false, SMTPS.hSvrConfig) &&
USmtpCheckMailDomain(SMTPS.hSvrConfig, szMailerDomain) < 0) {
ErrorPush();
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS, ppszRetDomains[0], "", "SNDR=ENODNS", 0);
pszSMTPError = SysStrDup("505 Your domain has no DNS/MX entries");
return ErrorPop();
}
/* Check if mail come from a spammer address ( spam-address.tab ) */
if (USmtpSpamAddressCheck(ppszRetDomains[0]) < 0) {
ErrorPush();
if (SMTPLogEnabled(SMTPS.pThCfg->hThShb, SMTPS.pSMTPCfg))
SMTPLogSession(SMTPS, ppszRetDomains[0], "", "SNDR=ESPAM", 0);
if ((pszSMTPError =
SvrGetConfigVar(SMTPS.hSvrConfig, "SmtpMsgIPBanSpamAddress")) == NULL)
pszSMTPError = SysStrDup("504 You are registered as spammer");
return ErrorPop();
}
/* Check SMTP after POP3 authentication */
if (SvrTestConfigFlag("EnableAuthSMTP-POP3", true, SMTPS.hSvrConfig))
SMTPTryPopAuthIpCheck(SMTPS, szMailerUser, szMailerDomain);
/* Check extended mail from parameters */
if (SMTPCheckMailParams(pszCommand, ppszRetDomains, SMTPS, pszSMTPError) < 0)
return ErrGetErrorCode();
/* Setup From string */
SysFree(SMTPS.pszFrom);
SMTPS.pszFrom = SysStrDup(ppszRetDomains[0]);
return 0;
}
static int SMTPAddMessageInfo(SMTPSession &SMTPS)
{
return USmtpAddMessageInfo(SMTPS.pMsgFile, SMTPS.szClientDomain, SMTPS.PeerInfo,
SMTPS.szSvrDomain, SMTPS.SockInfo, SMTP_SERVER_NAME);
}
static int SMTPHandleCmd_MAIL(char const *pszCommand, BSOCK_HANDLE hBSock, SMTPSession &SMTPS)
{
if (SMTPS.iSMTPState != stateHelo && SMTPS.iSMTPState != stateAuthenticated) {
SMTPResetSession(SMTPS);
SMTPSendError(hBSock, SMTPS, "503 Bad sequence of commands");
ErrSetErrorCode(ERR_SMTP_BAD_CMD_SEQUENCE);
return ERR_SMTP_BAD_CMD_SEQUENCE;
}
/* Do we need to be in TLS mode for this session? */
if ((SMTPS.ulFlags & SMTPF_WANT_TLS) && !(SMTPS.ulFlags & SMTPF_EASE_TLS) &&
strcmp(BSckBioName(hBSock), BSSL_BIO_NAME) != 0) {
SMTPSendError(hBSock, SMTPS,
"503 Bad sequence of commands (TLS needed for this session)");
ErrSetErrorCode(ERR_TLS_MODE_REQUIRED);
return ERR_TLS_MODE_REQUIRED;
}
/* Split the RETURN PATH */
char **ppszRetDomains = USmtpGetPathStrings(pszCommand);
if (ppszRetDomains == NULL) {
ErrorPush();
SMTPResetSession(SMTPS);
SMTPSendError(hBSock, SMTPS,
"501 Syntax error in parameters or arguments: (%d)",
ErrorFetch());