mod_negotiation.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

        else if (apr_isspace(c)) {
            /* Leading whitespace.  POSSIBLE continuation line
             * Also, possibly blank --- if so, we ungetc() the final newline
             * so that we will pick up the blank line the next time 'round.
             */

            while (c != '\n' && apr_isspace(c)) {
                if(apr_file_getc(&c, map) != APR_SUCCESS)
                    break;
            }

            apr_file_ungetc(c, map);

            if (c == '\n') {
                return header_seen;     /* Blank line */
            }

            /* Continuation */

            while (   cp < buf_end - 2
                   && (apr_file_getc(&c, map)) != APR_EOF
                   && c != '\n') {
                *cp++ = c;
            }

            *cp++ = '\n';
            *cp = '\0';
        }
        else {

            /* Line beginning with something other than whitespace */

            apr_file_ungetc(c, map);
            return header_seen;
        }
    }

    return header_seen;
}

static apr_off_t get_body(char *buffer, apr_size_t *len, const char *tag,
                          apr_file_t *map)
{
    char *endbody;
    int bodylen;
    int taglen;
    apr_off_t pos;

    taglen = strlen(tag);
    *len -= taglen;

    /* We are at the first character following a body:tag\n entry
     * Suck in the body, then backspace to the first char after the
     * closing tag entry.  If we fail to read, find the tag or back
     * up then we have a hosed file, so give up already
     */
    if (apr_file_read(map, buffer, len) != APR_SUCCESS) {
        return -1;
    }

    /* put a copy of the tag *after* the data read from the file
     * so that strstr() will find something with no reliance on
     * terminating '\0'
     */
    memcpy(buffer + *len, tag, taglen);
    endbody = strstr(buffer, tag);
    if (endbody == buffer + *len) {
        return -1;
    }
    bodylen = endbody - buffer;
    endbody += taglen;
    /* Skip all the trailing cruft after the end tag to the next line */
    while (*endbody) {
        if (*endbody == '\n') {
            ++endbody;
            break;
        }
        ++endbody;
    }

    pos = -(apr_off_t)(*len - (endbody - buffer));
    if (apr_file_seek(map, APR_CUR, &pos) != APR_SUCCESS) {
        return -1;
    }

    /* Give the caller back the actual body's file offset and length */
    *len = bodylen;
    return pos - (endbody - buffer);
}


/* Stripping out RFC822 comments */

static void strip_paren_comments(char *hdr)
{
    /* Hmmm... is this correct?  In Roy's latest draft, (comments) can nest! */
    /* Nope, it isn't correct.  Fails to handle backslash escape as well.    */

    while (*hdr) {
        if (*hdr == '"') {
            hdr = strchr(hdr, '"');
            if (hdr == NULL) {
                return;
            }
            ++hdr;
        }
        else if (*hdr == '(') {
            while (*hdr && *hdr != ')') {
                *hdr++ = ' ';
            }

            if (*hdr) {
                *hdr++ = ' ';
            }
        }
        else {
            ++hdr;
        }
    }
}

/* Getting to a header body from the header */

static char *lcase_header_name_return_body(char *header, request_rec *r)
{
    char *cp = header;

    for ( ; *cp && *cp != ':' ; ++cp) {
        *cp = apr_tolower(*cp);
    }

    if (!*cp) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                      "Syntax error in type map, no ':' in %s for header %s",
                      r->filename, header);
        return NULL;
    }

    do {
        ++cp;
    } while (*cp && apr_isspace(*cp));

    if (!*cp) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                      "Syntax error in type map --- no header body: %s for %s",
                      r->filename, header);
        return NULL;
    }

    return cp;
}

static int read_type_map(apr_file_t **map, negotiation_state *neg,
                         request_rec *rr)
{
    request_rec *r = neg->r;
    apr_file_t *map_ = NULL;
    apr_status_t status;
    char buffer[MAX_STRING_LEN];
    enum header_state hstate;
    struct var_rec mime_info;
    int has_content;

    if (!map)
        map = &map_;

    /* We are not using multiviews */
    neg->count_multiviews_variants = 0;

    if ((status = apr_file_open(map, rr->filename, APR_READ | APR_BUFFERED,
                APR_OS_DEFAULT, neg->pool)) != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r,
                      "cannot access type map file: %s", rr->filename);
        if (APR_STATUS_IS_ENOTDIR(status) || APR_STATUS_IS_ENOENT(status)) {
            return HTTP_NOT_FOUND;
        }
        else {
            return HTTP_FORBIDDEN;
        }
    }

    clean_var_rec(&mime_info);
    has_content = 0;

    do {
        hstate = get_header_line(buffer, MAX_STRING_LEN, *map);

        if (hstate == header_seen) {
            char *body1 = lcase_header_name_return_body(buffer, neg->r);
            const char *body;

            if (body1 == NULL) {
                return HTTP_INTERNAL_SERVER_ERROR;
            }

            strip_paren_comments(body1);
            body = body1;

            if (!strncmp(buffer, "uri:", 4)) {
                mime_info.file_name = ap_get_token(neg->pool, &body, 0);
            }
            else if (!strncmp(buffer, "content-type:", 13)) {
                struct accept_rec accept_info;

                get_entry(neg->pool, &accept_info, body);
                set_mime_fields(&mime_info, &accept_info);
                has_content = 1;
            }
            else if (!strncmp(buffer, "content-length:", 15)) {
                char *errp;
                apr_off_t number;

                if (apr_strtoff(&number, body, &errp, 10)
                    || *errp || number < 0) {
                    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                                  "Parse error in type map, Content-Length: "
                                  "'%s' in %s is invalid.",
                                  body, r->filename);
                    break;
                }
                mime_info.bytes = number;
                has_content = 1;
            }
            else if (!strncmp(buffer, "content-language:", 17)) {
                mime_info.content_languages = do_languages_line(neg->pool,
                                                                &body);
                has_content = 1;
            }
            else if (!strncmp(buffer, "content-encoding:", 17)) {
                mime_info.content_encoding = ap_get_token(neg->pool, &body, 0);
                has_content = 1;
            }
            else if (!strncmp(buffer, "description:", 12)) {
                char *desc = apr_pstrdup(neg->pool, body);
                char *cp;

                for (cp = desc; *cp; ++cp) {
                    if (*cp=='\n') *cp=' ';
                }
                if (cp>desc) *(cp-1)=0;
                mime_info.description = desc;
            }
            else if (!strncmp(buffer, "body:", 5)) {
                char *tag = apr_pstrdup(neg->pool, body);
                char *eol = strchr(tag, '\0');
                apr_size_t len = MAX_STRING_LEN;
                while (--eol >= tag && apr_isspace(*eol))
                    *eol = '\0';
                if ((mime_info.body = get_body(buffer, &len, tag, *map)) < 0) {
                    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                                  "Syntax error in type map, no end tag '%s'"
                                  "found in %s for Body: content.",
                                  tag, r->filename);
                     break;
                }
                mime_info.bytes = len;
                mime_info.file_name = apr_filepath_name_get(rr->filename);
            }
        }
        else {
            if (*mime_info.file_name && has_content) {
                void *new_var = apr_array_push(neg->avail_vars);

                memcpy(new_var, (void *) &mime_info, sizeof(var_rec));
            }

            clean_var_rec(&mime_info);
            has_content = 0;
        }
    } while (hstate != header_eof);

    if (map_)
        apr_file_close(map_);

    set_vlist_validator(r, rr);

    return OK;
}


/* Sort function used by read_types_multi. */
static int variantsortf(var_rec *a, var_rec *b) {

    /* First key is the source quality, sort in descending order. */

    /* XXX: note that we currently implement no method of setting the
     * source quality for multiviews variants, so we are always comparing
     * 1.0 to 1.0 for now
     */
    if (a->source_quality < b->source_quality)
        return 1;
    if (a->source_quality > b->source_quality)
        return -1;

    /* Second key is the variant name */
    return strcmp(a->file_name, b->file_name);
}

/*****************************************************************
 *
 * Same as read_type_map, except we use a filtered directory listing
 * as the map...
 */

static int read_types_multi(negotiation_state *neg)
{
    request_rec *r = neg->r;

    char *filp;
    int prefix_len;
    apr_dir_t *dirp;
    apr_finfo_t dirent;
    apr_status_t status;
    struct var_rec mime_info;
    struct accept_rec accept_info;
    void *new_var;
    int anymatch = 0;

    clean_var_rec(&mime_info);

    if (r->proxyreq || !r->filename
                    || !ap_os_is_path_absolute(neg->pool, r->filename)) {
        return DECLINED;
    }

    /* Only absolute paths here */
    if (!(filp = strrchr(r->filename, '/'))) {
        return DECLINED;
    }
    ++filp;
    prefix_len = strlen(filp);

    if ((status = apr_dir_open(&dirp, neg->dir_name,
                               neg->pool)) != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r,
                    "cannot read directory for multi: %s", neg->dir_name);
        return HTTP_FORBIDDEN;
    }

    while (apr_dir_read(&dirent, APR_FINFO_DIRENT, dirp) == APR_SUCCESS) {
        apr_array_header_t *exception_list;
        request_rec *sub_req;

        /* Do we have a match? */
#ifdef CASE_BLIND_FILESYSTEM
        if (strncasecmp(dirent.name, filp, prefix_len)) {
#else
        if (strncmp(dirent.name, filp, prefix_len)) {
#endif
            continue;
        }
        if (dirent.name[prefix_len] != '.') {
            continue;
        }

        /* Don't negotiate directories and other unusual files
         * Really shouldn't see anything but DIR/LNK/REG here,
         * and we aught to discover if the LNK was interesting.
         *
         * Of course, this only helps platforms that capture the
         * the filetype in apr_dir_read(), which most can once
         * they are optimized with some magic [it's known to the
         * dirent, not associated to the inode, on most FS's.]
         */
        if ((dirent.valid & APR_FINFO_TYPE) && (dirent.filetype == APR_DIR))
            continue;

        /* Ok, something's here.  Maybe nothing useful.  Remember that
         * we tried, if we completely fail, so we can reject the request!
         */
        anymatch = 1;

        /* See if it's something which we have access to, and which
         * has a known type and encoding (as opposed to something
         * which we'll be slapping default_type on later).
         */
        sub_req = ap_sub_req_lookup_dirent(&dirent, r, AP_SUBREQ_MERGE_ARGS,
                                           NULL);

        /* Double check, we still don't multi-resolve non-ordinary files
         */
        if (sub_req->finfo.filetype != APR_REG)
            continue;

        /* If it has a handler, we'll pretend it's a CGI script,
         * since that's a good indication of the sort of thing it
         * might be doing.
         */
        if (sub_req->handler && !sub_req->content_type) {
            ap_set_content_type(sub_req, CGI_MAGIC_TYPE);
        }

        /*