FINGSvr.cpp

/*
 *  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 <davidel@xmailserver.org>
 *
 */

#include "SysInclude.h"
#include "SysDep.h"
#include "SvrDefines.h"
#include "ShBlocks.h"
#include "SList.h"
#include "BuffSock.h"
#include "SSLBind.h"
#include "SSLConfig.h"
#include "StrUtils.h"
#include "ResLocks.h"
#include "MiscUtils.h"
#include "SvrUtils.h"
#include "UsrUtils.h"
#include "ExtAliases.h"
#include "UsrMailList.h"
#include "MessQueue.h"
#include "SMTPUtils.h"
#include "MailConfig.h"
#include "AppDefines.h"
#include "MailSvr.h"
#include "FINGSvr.h"

#define FING_IPMAP_FILE         "finger.ipmap.tab"
#define FING_LOG_FILE           "finger"

static int FINGLogEnabled(SHB_HANDLE hShbFING, FINGConfig *pFINGCfg = NULL);
static int FINGDumpUser(char const *pszUser, char const *pszDomain,
            BSOCK_HANDLE hBSock, FINGConfig *pFINGCfg);

static int FINGCheckPeerIP(SYS_SOCKET SockFD)
{
    char szIPMapFile[SYS_MAX_PATH] = "";

    CfgGetRootPath(szIPMapFile, sizeof(szIPMapFile));
    StrNCat(szIPMapFile, FING_IPMAP_FILE, sizeof(szIPMapFile));

    SysLogMessage(LOG_LEV_DEBUG, "Going to look at config file: '%s'\n", szIPMapFile);

    if (SysExistFile(szIPMapFile)) {
        SYS_INET_ADDR PeerInfo;

        ZeroData(PeerInfo); /* [i_a] */

        if (SysGetPeerInfo(SockFD, PeerInfo) < 0)
            return ErrGetErrorCode();

        if (MscCheckAllowedIP(szIPMapFile, PeerInfo, true) < 0)
            return ErrGetErrorCode();
    }

    return 0;
}

static FINGConfig *FINGGetConfigCopy(SHB_HANDLE hShbFING)
{
    FINGConfig *pFINGCfg = (FINGConfig *) ShbLock(hShbFING);

    if (pFINGCfg == NULL)
        return NULL;

    FINGConfig *pFINGCfgCopy = (FINGConfig *) SysAlloc(sizeof(FINGConfig));

    if (pFINGCfgCopy != NULL)
        memcpy(pFINGCfgCopy, pFINGCfg, sizeof(FINGConfig));

    ShbUnlock(hShbFING);

    return pFINGCfgCopy;
}

static int FINGLogEnabled(SHB_HANDLE hShbFING, FINGConfig *pFINGCfg)
{
    int iDoUnlock = 0;

    if (pFINGCfg == NULL) {
        if ((pFINGCfg = (FINGConfig *) ShbLock(hShbFING)) == NULL)
            return ErrGetErrorCode();
        ++iDoUnlock;
    }

    unsigned long ulFlags = pFINGCfg->ulFlags;

    if (iDoUnlock)
        ShbUnlock(hShbFING);

    return (ulFlags & FINGF_LOG_ENABLED) ? 1 : 0;
}

static int FINGLogSession(char const *pszSockHost, char const *pszSockDomain,
              SYS_INET_ADDR & PeerInfo, char const *pszQuery)
{
    char szTime[256] = "";

    MscGetTimeNbrString(szTime, sizeof(szTime) - 1);

    RLCK_HANDLE hResLock = RLckLockEX(SVR_LOGS_DIR SYS_SLASH_STR FING_LOG_FILE);

    if (hResLock == INVALID_RLCK_HANDLE)
        return ErrGetErrorCode();

    char szIP[128] = "???.???.???.???";

    MscFileLog(FING_LOG_FILE, "\"%s\""
           "\t\"%s\""
           "\t\"%s\""
           "\t\"%s\""
           "\t\"%s\""
           "\n", pszSockHost, pszSockDomain, SysInetNToA(PeerInfo, szIP, sizeof(szIP)),
           szTime, pszQuery);

    RLckUnlockEX(hResLock);

    return 0;
}

static int FINGDumpMailingList(UserInfo * pUI, BSOCK_HANDLE hBSock, FINGConfig * pFINGCfg)
{
    USRML_HANDLE hUsersDB = UsrMLOpenDB(pUI);

    if (hUsersDB == INVALID_USRML_HANDLE)
        return ErrGetErrorCode();

    /* Mailing list scan */
    MLUserInfo *pMLUI = UsrMLGetFirstUser(hUsersDB);

    for (; pMLUI != NULL; pMLUI = UsrMLGetNextUser(hUsersDB)) {
        char szUser[MAX_ADDR_NAME] = "";
        char szDomain[MAX_ADDR_NAME] = "";

        if (USmtpSplitEmailAddr(pMLUI->pszAddress, szUser, szDomain) < 0) {
            ErrorPush();
            UsrMLFreeUser(pMLUI);
            UsrMLCloseDB(hUsersDB);
            return ErrorPop();
        }
        /* Dump user */
        FINGDumpUser(szUser, szDomain, hBSock, pFINGCfg);

        UsrMLFreeUser(pMLUI);
    }
    UsrMLCloseDB(hUsersDB);

    return 0;
}

static int FINGDumpUser(char const *pszUser, char const *pszDomain,
            BSOCK_HANDLE hBSock, FINGConfig *pFINGCfg)
{
    /* Lookup user */
    char szRealAddr[MAX_ADDR_NAME] = "";
    UserInfo *pUI = UsrGetUserByNameOrAlias(pszDomain, pszUser, szRealAddr);

    if (pUI != NULL) {
        if (UsrGetUserType(pUI) == usrTypeUser) {
            /* Local user case */
            char *pszRealName = UsrGetUserInfoVar(pUI, "RealName");
            char *pszHomePage = UsrGetUserInfoVar(pUI, "HomePage");
            char szRespBuffer[2048] = "";

            SysSNPrintf(szRespBuffer, sizeof(szRespBuffer),
                    "EMail       : %s\r\n"
                    "  Real Name : %s\r\n"
                    "  Home Page : %s",
                    szRealAddr,
                    (pszRealName != NULL) ? pszRealName : "??",
                    (pszHomePage != NULL) ? pszHomePage : "??");

            BSckSendString(hBSock, szRespBuffer, pFINGCfg->iTimeout);

            SysFree(pszRealName);
            SysFree(pszHomePage);
        } else {
            /* Local mailing list case */

            FINGDumpMailingList(pUI, hBSock, pFINGCfg);
        }
        UsrFreeUserInfo(pUI);
    } else {
        ErrSetErrorCode(ERR_USER_NOT_FOUND);
        return ERR_USER_NOT_FOUND;
    }

    return 0;
}

static int FINGProcessQuery(char const *pszQuery, BSOCK_HANDLE hBSock,
                FINGConfig * pFINGCfg, char const *pszSockDomain,
                SVRCFG_HANDLE hSvrConfig)
{
    /* Check for verbose query */
    int iVerbose = 0;

    if (pszQuery[0] == '/') {
        if (toupper(pszQuery[1]) != 'W') {
            BSckSendString(hBSock, "Invalid query", pFINGCfg->iTimeout);

            ErrSetErrorCode(ERR_FINGER_QUERY_FORMAT);
            return ERR_FINGER_QUERY_FORMAT;
        }

        ++iVerbose;
        pszQuery += 2;
    }
    /* Discard spaces */
    for (; *pszQuery == ' '; pszQuery++);

    if (*pszQuery == '\0') {
        BSckSendString(hBSock, "Empty query not allowed", pFINGCfg->iTimeout);

        ErrSetErrorCode(ERR_FINGER_QUERY_FORMAT);
        return ERR_FINGER_QUERY_FORMAT;
    }
    /* Split user-domain */
    char szUser[MAX_ADDR_NAME] = "";
    char szDomain[MAX_ADDR_NAME] = "";

    if (strchr(pszQuery, '@') != NULL) {
        if (USmtpSplitEmailAddr(pszQuery, szUser, szDomain) < 0) {
            ErrorPush();

            BSckSendString(hBSock, "Invalid query", pFINGCfg->iTimeout);

            return ErrorPop();
        }
    } else
        StrSNCpy(szUser, pszQuery);

    /* Check if indirect query */
    if (strchr(szDomain, '@') != NULL) {
        BSckSendString(hBSock, "Indirect query not allowed", pFINGCfg->iTimeout);

        ErrSetErrorCode(ERR_FINGER_QUERY_FORMAT);
        return ERR_FINGER_QUERY_FORMAT;
    }
    /* Setup domain name in case of username only query */
    if (IsEmptyString(szDomain)) {
        if (SvrConfigVar("POP3Domain", szDomain, sizeof(szDomain), hSvrConfig) < 0) {
            if (strlen(pszSockDomain) == 0) {
                if (SvrConfigVar
                    ("RootDomain", szDomain, sizeof(szDomain), hSvrConfig) < 0) {
                    ErrorPush();

                    BSckSendString(hBSock, "User not found",
                               pFINGCfg->iTimeout);

                    return ErrorPop();
                }
            } else
                StrSNCpy(szDomain, pszSockDomain);
        }
    }
    /* Dump user */
    if (FINGDumpUser(szUser, szDomain, hBSock, pFINGCfg) < 0) {
        ErrorPush();

        BSckSendString(hBSock, "User not found", pFINGCfg->iTimeout);

        return ErrorPop();
    }

    return 0;
}

static int FINGHandleSession(ThreadConfig const *pThCfg, BSOCK_HANDLE hBSock)
{
    FINGConfig *pFINGCfg = FINGGetConfigCopy(pThCfg->hThShb);

    /* Get client socket info */
    SYS_INET_ADDR PeerInfo;

    ZeroData(PeerInfo); /* [i_a] */

    if (SysGetPeerInfo(BSckGetAttachedSocket(hBSock), PeerInfo) < 0) {
        ErrorPush();
        BSckSendString(hBSock, ErrGetErrorString(ErrorFetch()), pFINGCfg->iTimeout);
        SysFree(pFINGCfg);

        SysLogMessage(LOG_LEV_ERROR, "%s\n", ErrGetErrorString(ErrorFetch()));
        return ErrorPop();
    }

    /* Get server socket FQDN */
    char szSvrFQDN[MAX_HOST_NAME] = "";

    if (MscGetSockHost(BSckGetAttachedSocket(hBSock), szSvrFQDN,
               sizeof(szSvrFQDN)) < 0) {
        ErrorPush();
        BSckSendString(hBSock, ErrGetErrorString(ErrorFetch()), pFINGCfg->iTimeout);
        SysFree(pFINGCfg);

        SysLogMessage(LOG_LEV_ERROR, "%s\n", ErrGetErrorString(ErrorFetch()));
        return ErrorPop();
    }

    char szSockHost[MAX_HOST_NAME] = "";
    char szSockDomain[MAX_HOST_NAME] = "";

    MscSplitFQDN(szSvrFQDN, szSockHost, sizeof(szSockHost),
             szSockDomain, sizeof(szSockDomain));

    char szIP[128] = "???.???.???.???";

    SysLogMessage(LOG_LEV_MESSAGE, "FINGER client connection from [%s]\n",
              SysInetNToA(PeerInfo, szIP, sizeof(szIP)));

    char szQuery[1024] = "";

    if (BSckGetString(hBSock, szQuery, sizeof(szQuery) - 1, pFINGCfg->iTimeout) != NULL &&
        MscCmdStringCheck(szQuery) == 0) {
        /* Log FINGER question */
        if (FINGLogEnabled(hShbFING))
            FINGLogSession(szSockHost, szSockDomain, PeerInfo, szQuery);

        SysLogMessage(LOG_LEV_MESSAGE, "FINGER query [%s] : \"%s\"\n",
                  SysInetNToA(PeerInfo, szIP, sizeof(szIP)), szQuery);

        SVRCFG_HANDLE hSvrConfig = SvrGetConfigHandle();

        FINGProcessQuery(szQuery, hBSock, pFINGCfg, szSockDomain, hSvrConfig);

        if (hSvrConfig != INVALID_SVRCFG_HANDLE)
            SvrReleaseConfigHandle(hSvrConfig);
    }
    SysFree(pFINGCfg);

    SysLogMessage(LOG_LEV_MESSAGE, "FINGER client exit [%s]\n",
              SysInetNToA(PeerInfo, szIP, sizeof(szIP)));

    return 0;
}

unsigned int FINGClientThread(void *pThreadData)
{
    ThreadCreateCtx *pThCtx = (ThreadCreateCtx *) pThreadData;

    /* Check IP permission */
    if (FINGCheckPeerIP(pThCtx->SockFD) < 0) {
        ErrorPush();
        SysLogMessage(LOG_LEV_ERROR, "%s\n", ErrGetErrorString());
        SysCloseSocket(pThCtx->SockFD);
        SysFree(pThCtx);
        return ErrorPop();
    }

    /* Link socket to the bufferer */
    BSOCK_HANDLE hBSock = BSckAttach(pThCtx->SockFD);

    if (hBSock == INVALID_BSOCK_HANDLE) {
        ErrorPush();
        SysCloseSocket(pThCtx->SockFD);
        SysFree(pThCtx);
        return ErrorPop();
    }

    /*
     * Do we need to switch to TLS?
     */
    if (pThCtx->pThCfg->ulFlags & THCF_USE_SSL) {
        int iError;
        SslServerBind SSLB;
        SslBindEnv SslE;

        if (CSslBindSetup(&SSLB) < 0) {
            ErrorPush();
            BSckDetach(hBSock, 1);
            SysFree(pThCtx);
            return ErrorPop();
        }
        ZeroData(SslE);

        iError = BSslBindServer(hBSock, &SSLB, MscSslEnvCB, &SslE);

        CSslBindCleanup(&SSLB);
        if (iError < 0) {
            ErrorPush();
            BSckDetach(hBSock, 1);
            SysFree(pThCtx);
            return ErrorPop();
        }
        /*
         * We may want to add verify code here ...
         */

        SysFree(SslE.pszIssuer);
        SysFree(SslE.pszSubject);
    }
    /* Increase threads count */
    FINGConfig *pFINGCfg = (FINGConfig *) ShbLock(pThCtx->pThCfg->hThShb);

    if (pFINGCfg == NULL) {
        ErrorPush();
        SysLogMessage(LOG_LEV_ERROR, "%s\n", ErrGetErrorString());
        BSckDetach(hBSock, 1);
        SysFree(pThCtx);
        return ErrorPop();
    }
    ++pFINGCfg->lThreadCount;
    ShbUnlock(pThCtx->pThCfg->hThShb);

    /* Handle client session */
    FINGHandleSession(pThCtx->pThCfg, hBSock);

    /* Decrease threads count */
    pFINGCfg = (FINGConfig *) ShbLock(pThCtx->pThCfg->hThShb);

    if (pFINGCfg == NULL) {
        ErrorPush();
        SysLogMessage(LOG_LEV_ERROR, "%s\n", ErrGetErrorString());
        return ErrorPop();
    }
    --pFINGCfg->lThreadCount;
    ShbUnlock(pThCtx->pThCfg->hThShb);

    /* Unlink socket from the bufferer and close it */
    BSckDetach(hBSock, 1);
    SysFree(pThCtx);

    return 0;
}