configfile.c

基于ntp协议的网络时间服务程序

    return pRes;
}


/*  filePreset
 *
 *  Load a file containing presetting information (a configuration file).
 */
static void
filePreset(
    tOptions*     pOpts,
    char const*   pzFileName,
    int           direction )
{
    tmap_info_t   cfgfile;
    tOptState     st = OPTSTATE_INITIALIZER(PRESET);
    char*         pzFileText =
        text_mmap( pzFileName, PROT_READ|PROT_WRITE, MAP_PRIVATE, &cfgfile );

    if (TEXT_MMAP_FAILED_ADDR(pzFileText))
        return;

    if (direction == DIRECTION_CALLED) {
        st.flags  = OPTST_DEFINED;
        direction = DIRECTION_PROCESS;
    }

    /*
     *  IF this is called via "optionProcess", then we are presetting.
     *  This is the default and the PRESETTING bit will be set.
     *  If this is called via "optionFileLoad", then the bit is not set
     *  and we consider stuff set herein to be "set" by the client program.
     */
    if ((pOpts->fOptSet & OPTPROC_PRESETTING) == 0)
        st.flags = OPTST_SET;

    do  {
        while (isspace( (int)*pzFileText ))  pzFileText++;

        if (isalpha( (int)*pzFileText )) {
            pzFileText = handleConfig( pOpts, &st, pzFileText, direction );

        } else switch (*pzFileText) {
        case '<':
            if (isalpha( (int)pzFileText[1] ))
                pzFileText = handleStructure(pOpts, &st, pzFileText, direction);

            else switch (pzFileText[1]) {
            case '?':
                pzFileText = handleDirective( pOpts, pzFileText );
                break;

            case '!':
                pzFileText = handleComment( pzFileText );
                break;

            case '/':
                pzFileText = strchr( pzFileText+2, '>' );
                if (pzFileText++ != NULL)
                    break;

            default:
                goto all_done;
            }
            break;

        case '[':
            pzFileText = handleProgramSection( pOpts, pzFileText );
            break;

        case '#':
            pzFileText = strchr( pzFileText+1, '\n' );
            break;

        default:
            goto all_done; /* invalid format */
        }
    } while (pzFileText != NULL);

 all_done:
    text_munmap( &cfgfile );
}


/*  handleComment
 *
 *  "pzText" points to a "<!" sequence.
 *  Theoretically, we should ensure that it begins with "<!--",
 *  but actually I don't care that much.  It ends with "-->".
 */
static char*
handleComment( char* pzText )
{
    char* pz = strstr( pzText, "-->" );
    if (pz != NULL)
        pz += 3;
    return pz;
}


/*  handleConfig
 *
 *  "pzText" points to the start of some value name.
 *  The end of the entry is the end of the line that is not preceded by
 *  a backslash escape character.  The string value is always processed
 *  in "cooked" mode.
 */
static char*
handleConfig(
    tOptions*     pOpts,
    tOptState*    pOS,
    char*         pzText,
    int           direction )
{
    char* pzName = pzText++;
    char* pzEnd  = strchr( pzText, '\n' );

    if (pzEnd == NULL)
        return pzText + strlen(pzText);

    while (ISNAMECHAR( (int)*pzText ))  pzText++;
    while (isspace( (int)*pzText )) pzText++;
    if (pzText > pzEnd) {
    name_only:
        *pzEnd++ = NUL;
        loadOptionLine( pOpts, pOS, pzName, direction, OPTION_LOAD_UNCOOKED );
        return pzEnd;
    }

    /*
     *  Either the first character after the name is a ':' or '=',
     *  or else we must have skipped over white space.  Anything else
     *  is an invalid format and we give up parsing the text.
     */
    if ((*pzText == '=') || (*pzText == ':')) {
        while (isspace( (int)*++pzText ))   ;
        if (pzText > pzEnd)
            goto name_only;
    } else if (! isspace((int)pzText[-1]))
        return NULL;

    /*
     *  IF the value is continued, remove the backslash escape and push "pzEnd"
     *  on to a newline *not* preceded by a backslash.
     */
    if (pzEnd[-1] == '\\') {
        char* pcD = pzEnd-1;
        char* pcS = pzEnd;

        for (;;) {
            char ch = *(pcS++);
            switch (ch) {
            case NUL:
                pcS = NULL;

            case '\n':
                *pcD = NUL;
                pzEnd = pcS;
                goto copy_done;

            case '\\':
                if (*pcS == '\n') {
                    ch = *(pcS++);
                }
                /* FALLTHROUGH */
            default:
                *(pcD++) = ch;
            }
        } copy_done:;

    } else {
        /*
         *  The newline was not preceded by a backslash.  NUL it out
         */
        *(pzEnd++) = NUL;
    }

    /*
     *  "pzName" points to what looks like text for one option/configurable.
     *  It is NUL terminated.  Process it.
     */
    loadOptionLine( pOpts, pOS, pzName, direction, OPTION_LOAD_UNCOOKED );

    return pzEnd;
}


/*  handleDirective
 *
 *  "pzText" points to a "<?" sequence.
 *  For the moment, we only handle "<?program" directives.
 */
static char*
handleDirective(
    tOptions*     pOpts,
    char*         pzText )
{
    char   ztitle[32] = "<?";
    size_t title_len = strlen( zProg );
    size_t name_len;

    if (  (strncmp( pzText+2, zProg, title_len ) != 0)
       || (! isspace( (int)pzText[title_len+2] )) )  {
        pzText = strchr( pzText+2, '>' );
        if (pzText != NULL)
            pzText++;
        return pzText;
    }

    name_len = strlen( pOpts->pzProgName );
    strcpy( ztitle+2, zProg );
    title_len += 2;

    do  {
        pzText += title_len;

        if (isspace((int)*pzText)) {
            while (isspace((int)*pzText))  pzText++;
            if (  (strneqvcmp( pzText, pOpts->pzProgName, (int)name_len) == 0)
               && (pzText[name_len] == '>'))  {
                pzText += name_len + 1;
                break;
            }
        }

        pzText = strstr( pzText, ztitle );
    } while (pzText != NULL);

    return pzText;
}


/*  handleProgramSection
 *
 *  "pzText" points to a '[' character.
 *  The "traditional" [PROG_NAME] segmentation of the config file.
 *  Do not ever mix with the "<?program prog-name>" variation.
 */
static char*
handleProgramSection(
    tOptions*     pOpts,
    char*         pzText )
{
    size_t len = strlen( pOpts->pzPROGNAME );
    if (   (strncmp( pzText+1, pOpts->pzPROGNAME, len ) == 0)
        && (pzText[len+1] == ']'))
        return strchr( pzText + len + 2, '\n' );

    if (len > 16)
        return NULL;

    {
        char z[24];
        sprintf( z, "[%s]", pOpts->pzPROGNAME );
        pzText = strstr( pzText, z );
    }

    if (pzText != NULL)
        pzText = strchr( pzText, '\n' );
    return pzText;
}


/*  handleStructure
 *
 *  "pzText" points to a '<' character, followed by an alpha.
 *  The end of the entry is either the "/>" following the name, or else a
 *  "</name>" string.
 */
static char*
handleStructure(
    tOptions*     pOpts,
    tOptState*    pOS,
    char*         pzText,
    int           direction )
{
    tOptionLoadMode mode = option_load_mode;
    tOptionValue     valu;

    char* pzName = ++pzText;
    char* pzData;
    char* pcNulPoint;

    while (ISNAMECHAR( *pzText ))  pzText++;
    pcNulPoint = pzText;
    valu.valType = OPARG_TYPE_STRING;

    switch (*pzText) {
    case ' ':
    case '\t':
        pzText = parseAttributes( pOpts, pzText, &mode, &valu );
        if (*pzText == '>')
            break;
        if (*pzText != '/')
            return NULL;
        /* FALLTHROUGH */

    case '/':
        if (pzText[1] != '>')
            return NULL;
        *pzText = NUL;
        pzText += 2;
        loadOptionLine( pOpts, pOS, pzName, direction, mode );
        return pzText;

    case '>':
        break;

    default:
        pzText = strchr( pzText, '>');
        if (pzText != NULL)
            pzText++;
        return pzText;
    }

    /*
     *  If we are here, we have a value.  "pzText" points to a closing angle
     *  bracket.  Separate the name from the value for a moment.
     */
    *pcNulPoint = NUL;
    pzData = ++pzText;

    /*
     *  Find the end of the option text and NUL terminate it
     */
    {
        char   z[64], *pz = z;
        size_t len = strlen(pzName) + 4;
        if (len > sizeof(z))
            pz = AGALOC(len, "scan name");

        sprintf( pz, "</%s>", pzName );
        *pzText = ' ';
        pzText = strstr( pzText, pz );
        if (pz != z) AGFREE(pz);

        if (pzText == NULL)
            return pzText;

        *pzText = NUL;

        pzText += len-1;
    }

    /*
     *  Rejoin the name and value for parsing by "loadOptionLine()".
     *  Erase any attributes parsed by "parseAttributes()".
     */
    memset(pcNulPoint, ' ', pzData - pcNulPoint);

    /*
     *  "pzName" points to what looks like text for one option/configurable.
     *  It is NUL terminated.  Process it.
     */
    loadOptionLine( pOpts, pOS, pzName, direction, mode );

    return pzText;
}


/*  internalFileLoad
 *
 *  Load a configuration file.  This may be invoked either from
 *  scanning the "homerc" list, or from a specific file request.
 *  (see "optionFileLoad()", the implementation for --load-opts)
 */
LOCAL void
internalFileLoad( tOptions* pOpts )
{
    int     idx;
    int     inc = DIRECTION_PRESET;
    char    zFileName[ AG_PATH_MAX+1 ];

    if (pOpts->papzHomeList == NULL)
        return;

    /*
     *  Find the last RC entry (highest priority entry)
     */
    for (idx = 0; pOpts->papzHomeList[ idx+1 ] != NULL; ++idx)  ;

    /*
     *  For every path in the home list, ...  *TWICE* We start at the last
     *  (highest priority) entry, work our way down to the lowest priority,
     *  handling the immediate options.
     *  Then we go back up, doing the normal options.
     */
    for (;;) {
        struct stat StatBuf;
        cch_t*  pzPath;

        /*
         *  IF we've reached the bottom end, change direction
         */
        if (idx < 0) {
            inc = DIRECTION_PROCESS;
            idx = 0;
        }

        pzPath = pOpts->papzHomeList[ idx ];

        /*
         *  IF we've reached the top end, bail out
         */
        if (pzPath == NULL)
            break;

        idx += inc;

        if (! optionMakePath( zFileName, (int)sizeof(zFileName),
                              pzPath, pOpts->pzProgPath ))
            continue;

        /*
         *  IF the file name we constructed is a directory,
         *  THEN append the Resource Configuration file name
         *  ELSE we must have the complete file name
         */
        if (stat( zFileName, &StatBuf ) != 0)
            continue; /* bogus name - skip the home list entry */

        if (S_ISDIR( StatBuf.st_mode )) {
            size_t len = strlen( zFileName );
            char* pz;

            if (len + 1 + strlen( pOpts->pzRcName ) >= sizeof( zFileName ))
                continue;

            pz = zFileName + len;
            if (pz[-1] != DIRCH)
                *(pz++) = DIRCH;