mod_mime_magic.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

            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,
                    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,
                      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,
                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,
                        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,
                    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,
                        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,
                    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,
                        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,
                    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,
                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,
                    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,
                    MODNAME ": invalid type %d in mconvert().", m->type);
        return 0;