mod_mime_magic.c

                MODNAME ": apprentice test");
    for (m = conf->magic; m; m = m->next) {
        if (apr_isprint((((unsigned long) m) >> 24) & 255) &&
            apr_isprint((((unsigned long) m) >> 16) & 255) &&
            apr_isprint((((unsigned long) m) >> 8) & 255) &&
            apr_isprint(((unsigned long) m) & 255)) {
            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01519)
                        MODNAME ": apprentice: POINTER CLOBBERED! "
                        "m=\"%c%c%c%c\" line=%d",
                        (((unsigned long) m) >> 24) & 255,
                        (((unsigned long) m) >> 16) & 255,
                        (((unsigned long) m) >> 8) & 255,
                        ((unsigned long) m) & 255,
                        prevm ? prevm->lineno : -1);
            break;
        }
        prevm = m;
    }
#endif

    return (errs ? -1 : 0);
}

/*
 * extend the sign bit if the comparison is to be signed
 */
static unsigned long signextend(server_rec *s, struct magic *m, unsigned long v)
{
    if (!(m->flag & UNSIGNED))
        switch (m->type) {
            /*
             * Do not remove the casts below.  They are vital. When later
             * compared with the data, the sign extension must have happened.
             */
        case BYTE:
            v = (char) v;
            break;
        case SHORT:
        case BESHORT:
        case LESHORT:
            v = (short) v;
            break;
        case DATE:
        case BEDATE:
        case LEDATE:
        case LONG:
        case BELONG:
        case LELONG:
            v = (long) v;
            break;
        case STRING:
            break;
        default:
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01520)
                        MODNAME ": can't happen: m->type=%d", m->type);
            return -1;
        }
    return v;
}

/*
 * parse one line from magic file, put into magic[index++] if valid
 */
static int parse(server_rec *serv, apr_pool_t *p, char *l, int lineno)
{
    struct magic *m;
    char *t, *s;
    magic_server_config_rec *conf = (magic_server_config_rec *)
                    ap_get_module_config(serv->module_config, &mime_magic_module);

    /* allocate magic structure entry */
    m = (struct magic *) apr_pcalloc(p, sizeof(struct magic));

    /* append to linked list */
    m->next = NULL;
    if (!conf->magic || !conf->last) {
        conf->magic = conf->last = m;
    }
    else {
        conf->last->next = m;
        conf->last = m;
    }

    /* set values in magic structure */
    m->flag = 0;
    m->cont_level = 0;
    m->lineno = lineno;

    while (*l == '>') {
        ++l;  /* step over */
        m->cont_level++;
    }

    if (m->cont_level != 0 && *l == '(') {
        ++l;  /* step over */
        m->flag |= INDIR;
    }

    /* get offset, then skip over it */
    m->offset = (int) strtol(l, &t, 0);
    if (l == t) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, serv, APLOGNO(01521)
                    MODNAME ": offset %s invalid", l);
    }
    l = t;

    if (m->flag & INDIR) {
        m->in.type = LONG;
        m->in.offset = 0;
        /*
         * read [.lbs][+-]nnnnn)
         */
        if (*l == '.') {
            switch (*++l) {
            case 'l':
                m->in.type = LONG;
                break;
            case 's':
                m->in.type = SHORT;
                break;
            case 'b':
                m->in.type = BYTE;
                break;
            default:
                ap_log_error(APLOG_MARK, APLOG_ERR, 0, serv, APLOGNO(01522)
                        MODNAME ": indirect offset type %c invalid", *l);
                break;
            }
            l++;
        }
        s = l;
        if (*l == '+' || *l == '-')
            l++;
        if (apr_isdigit((unsigned char) *l)) {
            m->in.offset = strtol(l, &t, 0);
            if (*s == '-')
                m->in.offset = -m->in.offset;
        }
        else
            t = l;
        if (*t++ != ')') {
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, serv, APLOGNO(01523)
                        MODNAME ": missing ')' in indirect offset");
        }
        l = t;
    }


    while (apr_isdigit((unsigned char) *l))
        ++l;
    EATAB;

#define NBYTE           4
#define NSHORT          5
#define NLONG           4
#define NSTRING         6
#define NDATE           4
#define NBESHORT        7
#define NBELONG         6
#define NBEDATE         6
#define NLESHORT        7
#define NLELONG         6
#define NLEDATE         6

    if (*l == 'u') {
        ++l;
        m->flag |= UNSIGNED;
    }

    /* get type, skip it */
    if (strncmp(l, "byte", NBYTE) == 0) {
        m->type = BYTE;
        l += NBYTE;
    }
    else if (strncmp(l, "short", NSHORT) == 0) {
        m->type = SHORT;
        l += NSHORT;
    }
    else if (strncmp(l, "long", NLONG) == 0) {
        m->type = LONG;
        l += NLONG;
    }
    else if (strncmp(l, "string", NSTRING) == 0) {
        m->type = STRING;
        l += NSTRING;
    }
    else if (strncmp(l, "date", NDATE) == 0) {
        m->type = DATE;
        l += NDATE;
    }
    else if (strncmp(l, "beshort", NBESHORT) == 0) {
        m->type = BESHORT;
        l += NBESHORT;
    }
    else if (strncmp(l, "belong", NBELONG) == 0) {
        m->type = BELONG;
        l += NBELONG;
    }
    else if (strncmp(l, "bedate", NBEDATE) == 0) {
        m->type = BEDATE;
        l += NBEDATE;
    }
    else if (strncmp(l, "leshort", NLESHORT) == 0) {
        m->type = LESHORT;
        l += NLESHORT;
    }
    else if (strncmp(l, "lelong", NLELONG) == 0) {
        m->type = LELONG;
        l += NLELONG;
    }
    else if (strncmp(l, "ledate", NLEDATE) == 0) {
        m->type = LEDATE;
        l += NLEDATE;
    }
    else {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, serv, APLOGNO(01524)
                    MODNAME ": type %s invalid", l);
        return -1;
    }
    /* New-style anding: "0 byte&0x80 =0x80 dynamically linked" */
    if (*l == '&') {
        ++l;
        m->mask = signextend(serv, m, strtol(l, &l, 0));
    }
    else
        m->mask = ~0L;
    EATAB;

    switch (*l) {
    case '>':
    case '<':
        /* Old-style anding: "0 byte &0x80 dynamically linked" */
    case '&':
    case '^':
    case '=':
        m->reln = *l;
        ++l;
        break;
    case '!':
        if (m->type != STRING) {
            m->reln = *l;
            ++l;
            break;
        }
        /* FALL THROUGH */
    default:
        if (*l == 'x' && apr_isspace(l[1])) {
            m->reln = *l;
            ++l;
            goto GetDesc;  /* Bill The Cat */
        }
        m->reln = '=';
        break;
    }
    EATAB;

    if (getvalue(serv, m, &l))
        return -1;
    /*
     * now get last part - the description
     */
  GetDesc:
    EATAB;
    if (l[0] == '\b') {
        ++l;
        m->nospflag = 1;
    }
    else if ((l[0] == '\\') && (l[1] == 'b')) {
        ++l;
        ++l;
        m->nospflag = 1;
    }
    else
        m->nospflag = 0;
    apr_cpystrn(m->desc, l, sizeof(m->desc));

#if MIME_MAGIC_DEBUG
    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, serv, APLOGNO(01525)
                MODNAME ": parse line=%d m=%x next=%x cont=%d desc=%s",
                lineno, m, m->next, m->cont_level, m->desc);
#endif /* MIME_MAGIC_DEBUG */

    return 0;
}

/*
 * Read a numeric value from a pointer, into the value union of a magic
 * pointer, according to the magic type.  Update the string pointer to point
 * just after the number read.  Return 0 for success, non-zero for failure.
 */
static int getvalue(server_rec *s, struct magic *m, char **p)
{
    int slen;

    if (m->type == STRING) {
        *p = getstr(s, *p, m->value.s, sizeof(m->value.s), &slen);
        m->vallen = slen;
    }
    else if (m->reln != 'x')
        m->value.l = signextend(s, m, strtol(*p, p, 0));
    return 0;
}

/*
 * Convert a string containing C character escapes.  Stop at an unescaped
 * space or tab. Copy the converted version to "p", returning its length in
 * *slen. Return updated scan pointer as function result.
 */
static char *getstr(server_rec *serv, register char *s, register char *p,
                    int plen, int *slen)
{
    char *origs = s, *origp = p;
    char *pmax = p + plen - 1;
    register int c;
    register int val;

    while ((c = *s++) != '\0') {
        if (apr_isspace(c))
            break;
        if (p >= pmax) {
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, serv, APLOGNO(01526)
                        MODNAME ": string too long: %s", origs);
            break;
        }
        if (c == '\\') {
            switch (c = *s++) {

            case '\0':
                goto out;

            default:
                *p++ = (char) c;
                break;

            case 'n':
                *p++ = '\n';
                break;

            case 'r':
                *p++ = '\r';
                break;

            case 'b':
                *p++ = '\b';
                break;

            case 't':
                *p++ = '\t';
                break;

            case 'f':
                *p++ = '\f';
                break;

            case 'v':
                *p++ = '\v';
                break;

                /* \ and up to 3 octal digits */
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
                val = c - '0';
                c = *s++;  /* try for 2 */
                if (c >= '0' && c <= '7') {
                    val = (val << 3) | (c - '0');
                    c = *s++;  /* try for 3 */
                    if (c >= '0' && c <= '7')
                        val = (val << 3) | (c - '0');
                    else
                        --s;
                }
                else
                    --s;
                *p++ = (char) val;
                break;

                /* \x and up to 3 hex digits */
            case 'x':
                val = 'x';            /* Default if no digits */
                c = hextoint(*s++);   /* Get next char */
                if (c >= 0) {
                    val = c;
                    c = hextoint(*s++);
                    if (c >= 0) {
                        val = (val << 4) + c;
                        c = hextoint(*s++);
                        if (c >= 0) {
                            val = (val << 4) + c;
                        }
                        else
                            --s;
                    }
                    else
                        --s;
                }
                else
                    --s;
                *p++ = (char) val;
                break;
            }
        }
        else
            *p++ = (char) c;
    }
  out:
    *p = '\0';
    *slen = p - origp;
    return s;
}


/* Single hex char to int; -1 if not a hex char. */
static int hextoint(int c)
{
    if (apr_isdigit(c))
        return c - '0';
    if ((c >= 'a') && (c <= 'f'))
        return c + 10 - 'a';
    if ((c >= 'A') && (c <= 'F'))
        return c + 10 - 'A';
    return -1;
}


/*
 * return DONE to indicate it's been handled
 * return OK to indicate it's a regular file still needing handling
 * other returns indicate a failure of some sort
 */
static int fsmagic(request_rec *r, const char *fn)
{
    switch (r->finfo.filetype) {
    case APR_DIR:
        magic_rsl_puts(r, DIR_MAGIC_TYPE);
        return DONE;
    case APR_CHR:
        /*
         * (void) magic_rsl_printf(r,"character special (%d/%d)",
         * major(sb->st_rdev), minor(sb->st_rdev));
         */
        (void) magic_rsl_puts(r, MIME_BINARY_UNKNOWN);
        return DONE;
    case APR_BLK:
        /*
         * (void) magic_rsl_printf(r,"block special (%d/%d)",
         * major(sb->st_rdev), minor(sb->st_rdev));
         */
        (void) magic_rsl_puts(r, MIME_BINARY_UNKNOWN);
        return DONE;
        /* TODO add code to handle V7 MUX and Blit MUX files */
    case APR_PIPE:
        /*
         * magic_rsl_puts(r,"fifo (named pipe)");
         */
        (void) magic_rsl_puts(r, MIME_BINARY_UNKNOWN);
        return DONE;
    case APR_LNK:
        /* We used stat(), the only possible reason for this is that the
         * symlink is broken.
         */
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01527)
                    MODNAME ": broken symlink (%s)", fn);
        return HTTP_INTERNAL_SERVER_ERROR;
    case APR_SOCK:
        magic_rsl_puts(r, MIME_BINARY_UNKNOWN);
        return DONE;
    case APR_REG:
        break;
    default:
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01528)
                      MODNAME ": invalid file type %d.", r->finfo.filetype);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /*
     * regular file, check next possibility
     */
    if (r->finfo.size == 0) {
        magic_rsl_puts(r, MIME_TEXT_UNKNOWN);
        return DONE;
    }
    return OK;
}

/*
 * softmagic - lookup one file in database (already read from /etc/magic by
 * apprentice.c). Passed the name and FILE * of one file to be typed.
 */
                /* ARGSUSED1 *//* nbytes passed for regularity, maybe need later */
static int softmagic(request_rec *r, unsigned char *buf, apr_size_t nbytes)
{
    if (match(r, buf, nbytes))
        return 1;

    return 0;
}

/*
 * Go through the whole list, stopping if you find a match.  Process all the
 * continuations of that match before returning.
 *
 * We support multi-level continuations:
 *
 * At any time when processing a successful top-level match, there is a current
 * continuation level; it represents the level of the last successfully
 * matched continuation.
 *
 * Continuations above that level are skipped as, if we see one, it means that
 * the continuation that controls them - i.e, the lower-level continuation
 * preceding them - failed to match.
 *
 * Continuations below that level are processed as, if we see one, it means
 * we've finished processing or skipping higher-level continuations under the
 * control of a successful or unsuccessful lower-level continuation, and are
 * now seeing the next lower-level continuation and should process it.  The
 * current continuation level reverts to the level of the one we're seeing.
 *
 * Continuations at the current level are processed as, if we see one, there's
 * no lower-level continuation that may have failed.
 *
 * If a continuation matches, we bump the current continuation level so that
 * higher-level continuations are processed.
 */
static int match(request_rec *r, unsigned char *s, apr_size_t nbytes)
{
#if MIME_MAGIC_DEBUG
    int rule_counter = 0;
#endif
    int cont_level = 0;
    int need_separator = 0;
    union VALUETYPE p;
    magic_server_config_rec *conf = (magic_server_config_rec *)
                ap_get_module_config(r->server->module_config, &mime_magic_module);
    struct magic *m;

#if MIME_MAGIC_DEBUG
    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01529)
                MODNAME ": match conf=%x file=%s m=%s m->next=%s last=%s",
                conf,
                conf->magicfile ? conf->magicfile : "NULL",
                conf->magic ? "set" : "NULL",
                (conf->magic && conf->magic->next) ? "set" : "NULL",
                conf->last ? "set" : "NULL");
#endif

#if MIME_MAGIC_DEBUG
    for (m = conf->magic; m; m = m->next) {
        if (apr_isprint((((unsigned long) m) >> 24) & 255) &&
            apr_isprint((((unsigned long) m) >> 16) & 255) &&
            apr_isprint((((unsigned long) m) >> 8) & 255) &&
            apr_isprint(((unsigned long) m) & 255)) {
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01530)
                        MODNAME ": match: POINTER CLOBBERED! "
                        "m=\"%c%c%c%c\"",
                        (((unsigned long) m) >> 24) & 255,
                        (((unsigned long) m) >> 16) & 255,
                        (((unsigned long) m) >> 8) & 255,
                        ((unsigned long) m) & 255);
            break;
        }
    }
#endif

    for (m = conf->magic; m; m = m->next) {
#if MIME_MAGIC_DEBUG
        rule_counter++;
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01531)
                    MODNAME ": line=%d desc=%s", m->lineno, m->desc);
#endif

        /* check if main entry matches */
        if (!mget(r, &p, s, m, nbytes) ||
            !mcheck(r, &p, m)) {
            struct magic *m_cont;

            /*
             * main entry didn't match, flush its continuations
             */
            if (!m->next || (m->next->cont_level == 0)) {
                continue;
            }

            m_cont = m->next;
            while (m_cont && (m_cont->cont_level != 0)) {
#if MIME_MAGIC_DEBUG
                rule_counter++;
                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01532)
                        MODNAME ": line=%d mc=%x mc->next=%x cont=%d desc=%s",
                            m_cont->lineno, m_cont,
                            m_cont->next, m_cont->cont_level,
                            m_cont->desc);
#endif
                /*
                 * this trick allows us to keep *m in sync when the continue
                 * advances the pointer
                 */
                m = m_cont;
                m_cont = m_cont->next;
            }
            continue;
        }

        /* if we get here, the main entry rule was a match */
        /* this will be the last run through the loop */
#if MIME_MAGIC_DEBUG
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01533)
                    MODNAME ": rule matched, line=%d type=%d %s",
                    m->lineno, m->type,
                    (m->type == STRING) ? m->value.s : "");
#endif

        /* print the match */
        mprint(r, &p, m);

        /*
         * If we printed something, we'll need to print a blank before we
         * print something else.
         */
        if (m->desc[0])
            need_separator = 1;
        /* and any continuations that match */
        cont_level++;
        /*
         * while (m && m->next && m->next->cont_level != 0 && ( m = m->next
         * ))
         */
        m = m->next;
        while (m && (m->cont_level != 0)) {
#if MIME_MAGIC_DEBUG
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01534)
                        MODNAME ": match line=%d cont=%d type=%d %s",
                        m->lineno, m->cont_level, m->type,
                        (m->type == STRING) ? m->value.s : "");
#endif
            if (cont_level >= m->cont_level) {
                if (cont_level > m->cont_level) {
                    /*
                     * We're at the end of the level "cont_level"
                     * continuations.
                     */
                    cont_level = m->cont_level;
                }
                if (mget(r, &p, s, m, nbytes) &&
                    mcheck(r, &p, m)) {
                    /*
                     * This continuation matched. Print its message, with a
                     * blank before it if the previous item printed and this
                     * item isn't empty.
                     */
                    /* space if previous printed */
                    if (need_separator
                        && (m->nospflag == 0)
                        && (m->desc[0] != '\0')
                        ) {
                        (void) magic_rsl_putchar(r, ' ');
                        need_separator = 0;
                    }
                    mprint(r, &p, m);
                    if (m->desc[0])
                        need_separator = 1;

                    /*
                     * If we see any continuations at a higher level, process
                     * them.
                     */
                    cont_level++;
                }
            }

            /* move to next continuation record */
            m = m->next;
        }
#if MIME_MAGIC_DEBUG
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01535)
                    MODNAME ": matched after %d rules", rule_counter);
#endif
        return 1;  /* all through */
    }
#if MIME_MAGIC_DEBUG
    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01536)
                MODNAME ": failed after %d rules", rule_counter);
#endif
    return 0;  /* no match at all */
}

static void mprint(request_rec *r, union VALUETYPE *p, struct magic *m)
{
    char *pp;
    unsigned long v;
    char time_str[APR_CTIME_LEN];

    switch (m->type) {
    case BYTE:
        v = p->b;
        break;

    case SHORT:
    case BESHORT:
    case LESHORT:
        v = p->h;
        break;

    case LONG:
    case BELONG:
    case LELONG:
        v = p->l;
        break;

    case STRING:
        if (m->reln == '=') {
            (void) magic_rsl_printf(r, m->desc, m->value.s);
        }
        else {
            (void) magic_rsl_printf(r, m->desc, p->s);
        }
        return;

    case DATE:
    case BEDATE:
    case LEDATE:
        apr_ctime(time_str, apr_time_from_sec(*(time_t *)&p->l));
        pp = time_str;
        (void) magic_rsl_printf(r, m->desc, pp);
        return;
    default:
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01537)
                    MODNAME ": invalid m->type (%d) in mprint().",
                    m->type);
        return;
    }

    v = signextend(r->server, m, v) & m->mask;
    (void) magic_rsl_printf(r, m->desc, (unsigned long) v);
}

/*
 * Convert the byte order of the data we are looking at
 */
static int mconvert(request_rec *r, union VALUETYPE *p, struct magic *m)
{
    char *rt;

    switch (m->type) {
    case BYTE:
    case SHORT:
    case LONG:
    case DATE:
        return 1;
    case STRING:
        /* Null terminate and eat the return */
        p->s[sizeof(p->s) - 1] = '\0';
        if ((rt = strchr(p->s, '\n')) != NULL)
            *rt = '\0';
        return 1;
    case BESHORT:
        p->h = (short) ((p->hs[0] << 8) | (p->hs[1]));
        return 1;
    case BELONG:
    case BEDATE:
        p->l = (long)
            ((p->hl[0] << 24) | (p->hl[1] << 16) | (p->hl[2] << 8) | (p->hl[3]));
        return 1;
    case LESHORT:
        p->h = (short) ((p->hs[1] << 8) | (p->hs[0]));
        return 1;
    case LELONG:
    case LEDATE:
        p->l = (long)
            ((p->hl[3] << 24) | (p->hl[2] << 16) | (p->hl[1] << 8) | (p->hl[0]));
        return 1;
    default:
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01538)
                    MODNAME ": invalid type %d in mconvert().", m->type);
        return 0;
    }
}


static int mget(request_rec *r, union VALUETYPE *p, unsigned char *s,
                struct magic *m, apr_size_t nbytes)
{
    long offset = m->offset;

    if (offset + sizeof(union VALUETYPE) > nbytes)
                  return 0;

    memcpy(p, s + offset, sizeof(union VALUETYPE));

    if (!mconvert(r, p, m))
        return 0;

    if (m->flag & INDIR) {

        switch (m->in.type) {
        case BYTE:
            offset = p->b + m->in.offset;
            break;
        case SHORT:
            offset = p->h + m->in.offset;
            break;
        case LONG:
            offset = p->l + m->in.offset;
            break;
        }

        if (offset + sizeof(union VALUETYPE) > nbytes)
                      return 0;

        memcpy(p, s + offset, sizeof(union VALUETYPE));

        if (!mconvert(r, p, m))
            return 0;
    }
    return 1;
}

static int mcheck(request_rec *r, union VALUETYPE *p, struct magic *m)
{
    register unsigned long l = m->value.l;
    register unsigned long v;
    int matched;

    if ((m->value.s[0] == 'x') && (m->value.s[1] == '\0')) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01539)
                    MODNAME ": BOINK");
        return 1;
    }

    switch (m->type) {
    case BYTE:
        v = p->b;
        break;

    case SHORT:
    case BESHORT:
    case LESHORT:
        v = p->h;
        break;

    case LONG:
    case BELONG:
    case LELONG:
    case DATE:
    case BEDATE:
    case LEDATE:
        v = p->l;
        break;

    case STRING:
        l = 0;
        /*
         * What we want here is: v = strncmp(m->value.s, p->s, m->vallen);
         * but ignoring any nulls.  bcmp doesn't give -/+/0 and isn't
         * universally available anyway.
         */
        v = 0;
        {
            register unsigned char *a = (unsigned char *) m->value.s;
            register unsigned char *b = (unsigned char *) p->s;
            register int len = m->vallen;

            while (--len >= 0)
                if ((v = *b++ - *a++) != 0)
                    break;
        }
        break;
    default:
        /*  bogosity, pretend that it just wasn't a match */
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01540)
                    MODNAME ": invalid type %d in mcheck().", m->type);
        return 0;
    }

    v = signextend(r->server, m, v) & m->mask;

    switch (m->reln) {
    case 'x':
#if MIME_MAGIC_DEBUG
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01541)
                    "%lu == *any* = 1", v);
#endif
        matched = 1;
        break;

    case '!':
        matched = v != l;
#if MIME_MAGIC_DEBUG
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01542)
                    "%lu != %lu = %d", v, l, matched);
#endif
        break;

    case '=':
        matched = v == l;
#if MIME_MAGIC_DEBUG
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01543)
                    "%lu == %lu = %d", v, l, matched);
#endif
        break;

    case '>':
        if (m->flag & UNSIGNED) {
            matched = v > l;
#if MIME_MAGIC_DEBUG
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01544)
                        "%lu > %lu = %d", v, l, matched);
#endif
        }
        else {
            matched = (long) v > (long) l;
#if MIME_MAGIC_DEBUG
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01545)
                        "%ld > %ld = %d", v, l, matched);
#endif
        }
        break;

    case '<':
        if (m->flag & UNSIGNED) {
            matched = v < l;
#if MIME_MAGIC_DEBUG
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01546)
                        "%lu < %lu = %d", v, l, matched);
#endif
        }
        else {
            matched = (long) v < (long) l;
#if MIME_MAGIC_DEBUG
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01547)
                        "%ld < %ld = %d", v, l, matched);
#endif
        }
        break;

    case '&':
        matched = (v & l) == l;
#if MIME_MAGIC_DEBUG
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01548)
                    "((%lx & %lx) == %lx) = %d", v, l, l, matched);
#endif
        break;

    case '^':
        matched = (v & l) != l;
#if MIME_MAGIC_DEBUG
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01549)
                    "((%lx & %lx) != %lx) = %d", v, l, l, matched);
#endif
        break;

    default:
        /* bogosity, pretend it didn't match */
        matched = 0;
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01550)
                    MODNAME ": mcheck: can't happen: invalid relation %d.",
                    m->reln);
        break;
    }

    return matched;
}

/* an optimization over plain strcmp() */
#define    STREQ(a, b)    (*(a) == *(b) && strcmp((a), (b)) == 0)

static int ascmagic(request_rec *r, unsigned char *buf, apr_size_t nbytes)
{
    int has_escapes = 0;
    unsigned char *s;
    char nbuf[SMALL_HOWMANY + 1];  /* one extra for terminating '\0' */
    char *token;
    const struct names *p;
    int small_nbytes;
    char *strtok_state;

    /* these are easy, do them first */

    /*
     * for troff, look for . + letter + letter or .\"; this must be done to
     * disambiguate tar archives' ./file and other trash from real troff
     * input.
     */
    if (*buf == '.') {
        unsigned char *tp = buf + 1;

        while (apr_isspace(*tp))
            ++tp;  /* skip leading whitespace */
        if ((apr_isalnum(*tp) || *tp == '\\') &&
             (apr_isalnum(*(tp + 1)) || *tp == '"')) {
            magic_rsl_puts(r, "application/x-troff");
            return 1;
        }
    }
    if ((*buf == 'c' || *buf == 'C') && apr_isspace(*(buf + 1))) {