mod_cgid.c

linux网络服务器工具

        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                     "write to cgi daemon process");
    }

    info = apr_palloc(r->pool, sizeof(struct cleanup_script_info));
    info->r = r;
    info->conn_id = r->connection->id;
    info->conf = conf;
    apr_pool_cleanup_register(r->pool, info,
                              cleanup_script,
                              apr_pool_cleanup_null);
    /* We are putting the socket discriptor into an apr_file_t so that we can
     * use a pipe bucket to send the data to the client.  APR will create
     * a cleanup for the apr_file_t which will close the socket, so we'll
     * get rid of the cleanup we registered when we created the socket.
     */

    apr_os_pipe_put_ex(&tempsock, &sd, 1, r->pool);
    apr_pool_cleanup_kill(r->pool, (void *)((long)sd), close_unix_socket);

    if ((argv0 = strrchr(r->filename, '/')) != NULL)
        argv0++;
    else
        argv0 = r->filename;

    /* Transfer any put/post args, CERN style...
     * Note that we already ignore SIGPIPE in the core server.
     */
    bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
    seen_eos = 0;
    child_stopped_reading = 0;
    if (conf->logname) {
        dbuf = apr_palloc(r->pool, conf->bufbytes + 1);
        dbpos = 0;
    }
    do {
        apr_bucket *bucket;

        rv = ap_get_brigade(r->input_filters, bb, AP_MODE_READBYTES,
                            APR_BLOCK_READ, HUGE_STRING_LEN);

        if (rv != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                          "Error reading request entity data");
            return HTTP_INTERNAL_SERVER_ERROR;
        }

        for (bucket = APR_BRIGADE_FIRST(bb);
             bucket != APR_BRIGADE_SENTINEL(bb);
             bucket = APR_BUCKET_NEXT(bucket))
        {
            const char *data;
            apr_size_t len;

            if (APR_BUCKET_IS_EOS(bucket)) {
                seen_eos = 1;
                break;
            }

            /* We can't do much with this. */
            if (APR_BUCKET_IS_FLUSH(bucket)) {
                continue;
            }

            /* If the child stopped, we still must read to EOS. */
            if (child_stopped_reading) {
                continue;
            }

            /* read */
            apr_bucket_read(bucket, &data, &len, APR_BLOCK_READ);

            if (conf->logname && dbpos < conf->bufbytes) {
                int cursize;

                if ((dbpos + len) > conf->bufbytes) {
                    cursize = conf->bufbytes - dbpos;
                }
                else {
                    cursize = len;
                }
                memcpy(dbuf + dbpos, data, cursize);
                dbpos += cursize;
            }

            /* Keep writing data to the child until done or too much time
             * elapses with no progress or an error occurs.
             */
            rv = apr_file_write_full(tempsock, data, len, NULL);

            if (rv != APR_SUCCESS) {
                /* silly script stopped reading, soak up remaining message */
                child_stopped_reading = 1;
            }
        }
        apr_brigade_cleanup(bb);
    }
    while (!seen_eos);

    if (conf->logname) {
        dbuf[dbpos] = '\0';
    }

    /* we're done writing, or maybe we didn't write at all;
     * force EOF on child's stdin so that the cgi detects end (or
     * absence) of data
     */
    shutdown(sd, 1);

    /* Handle script return... */
    if (!nph) {
        const char *location;
        char sbuf[MAX_STRING_LEN];
        int ret;

        bb = apr_brigade_create(r->pool, c->bucket_alloc);
        b = apr_bucket_pipe_create(tempsock, c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, b);
        b = apr_bucket_eos_create(c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, b);

        if ((ret = ap_scan_script_header_err_brigade(r, bb, sbuf))) {
            ret = log_script(r, conf, ret, dbuf, sbuf, bb, NULL);

            /*
             * ret could be HTTP_NOT_MODIFIED in the case that the CGI script
             * does not set an explicit status and ap_meets_conditions, which
             * is called by ap_scan_script_header_err_brigade, detects that
             * the conditions of the requests are met and the response is
             * not modified.
             * In this case set r->status and return OK in order to prevent
             * running through the error processing stack as this would
             * break with mod_cache, if the conditions had been set by
             * mod_cache itself to validate a stale entity.
             * BTW: We circumvent the error processing stack anyway if the
             * CGI script set an explicit status code (whatever it is) and
             * the only possible values for ret here are:
             *
             * HTTP_NOT_MODIFIED          (set by ap_meets_conditions)
             * HTTP_PRECONDITION_FAILED   (set by ap_meets_conditions)
             * HTTP_INTERNAL_SERVER_ERROR (if something went wrong during the
             * processing of the response of the CGI script, e.g broken headers
             * or a crashed CGI process).
             */
            if (ret == HTTP_NOT_MODIFIED) {
                r->status = ret;
                return OK;
            }

            return ret;
        }

        location = apr_table_get(r->headers_out, "Location");

        if (location && location[0] == '/' && r->status == 200) {

            /* Soak up all the script output */
            discard_script_output(bb);
            apr_brigade_destroy(bb);
            /* This redirect needs to be a GET no matter what the original
             * method was.
             */
            r->method = apr_pstrdup(r->pool, "GET");
            r->method_number = M_GET;

            /* We already read the message body (if any), so don't allow
             * the redirected request to think it has one. We can ignore
             * Transfer-Encoding, since we used REQUEST_CHUNKED_ERROR.
             */
            apr_table_unset(r->headers_in, "Content-Length");

            ap_internal_redirect_handler(location, r);
            return OK;
        }
        else if (location && r->status == 200) {
            /* XX Note that if a script wants to produce its own Redirect
             * body, it now has to explicitly *say* "Status: 302"
             */
            discard_script_output(bb);
            apr_brigade_destroy(bb);
            return HTTP_MOVED_TEMPORARILY;
        }

        ap_pass_brigade(r->output_filters, bb);
    }

    if (nph) {
        struct ap_filter_t *cur;

        /* get rid of all filters up through protocol...  since we
         * haven't parsed off the headers, there is no way they can
         * work
         */

        cur = r->proto_output_filters;
        while (cur && cur->frec->ftype < AP_FTYPE_CONNECTION) {
            cur = cur->next;
        }
        r->output_filters = r->proto_output_filters = cur;

        bb = apr_brigade_create(r->pool, c->bucket_alloc);
        b = apr_bucket_pipe_create(tempsock, c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, b);
        b = apr_bucket_eos_create(c->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, b);
        ap_pass_brigade(r->output_filters, bb);
    }

    return OK; /* NOT r->status, even if it has changed. */
}




/*============================================================================
 *============================================================================
 * This is the beginning of the cgi filter code moved from mod_include. This
 *   is the code required to handle the "exec" SSI directive.
 *============================================================================
 *============================================================================*/
static apr_status_t include_cgi(include_ctx_t *ctx, ap_filter_t *f,
                                apr_bucket_brigade *bb, char *s)
{
    request_rec *r = f->r;
    request_rec *rr = ap_sub_req_lookup_uri(s, r, f->next);
    int rr_status;

    if (rr->status != HTTP_OK) {
        ap_destroy_sub_req(rr);
        return APR_EGENERAL;
    }

    /* No hardwired path info or query allowed */
    if ((rr->path_info && rr->path_info[0]) || rr->args) {
        ap_destroy_sub_req(rr);
        return APR_EGENERAL;
    }
    if (rr->finfo.filetype != APR_REG) {
        ap_destroy_sub_req(rr);
        return APR_EGENERAL;
    }

    /* Script gets parameters of the *document*, for back compatibility */
    rr->path_info = r->path_info;       /* hard to get right; see mod_cgi.c */
    rr->args = r->args;

    /* Force sub_req to be treated as a CGI request, even if ordinary
     * typing rules would have called it something else.
     */
    ap_set_content_type(rr, CGI_MAGIC_TYPE);

    /* Run it. */
    rr_status = ap_run_sub_req(rr);
    if (ap_is_HTTP_REDIRECT(rr_status)) {
        const char *location = apr_table_get(rr->headers_out, "Location");

        if (location) {
            char *buffer;

            location = ap_escape_html(rr->pool, location);
            buffer = apr_pstrcat(ctx->pool, "<a href=\"", location, "\">",
                                 location, "</a>", NULL);

            APR_BRIGADE_INSERT_TAIL(bb, apr_bucket_pool_create(buffer,
                                    strlen(buffer), ctx->pool,
                                    f->c->bucket_alloc));
        }
    }

    ap_destroy_sub_req(rr);

    return APR_SUCCESS;
}

/* This is the special environment used for running the "exec cmd="
 *   variety of SSI directives.
 */
static void add_ssi_vars(request_rec *r)
{
    apr_table_t *e = r->subprocess_env;

    if (r->path_info && r->path_info[0] != '\0') {
        request_rec *pa_req;

        apr_table_setn(e, "PATH_INFO", ap_escape_shell_cmd(r->pool, r->path_info));

        pa_req = ap_sub_req_lookup_uri(ap_escape_uri(r->pool, r->path_info), r, NULL);
        if (pa_req->filename) {
            apr_table_setn(e, "PATH_TRANSLATED",
                           apr_pstrcat(r->pool, pa_req->filename, pa_req->path_info, NULL));
        }
        ap_destroy_sub_req(pa_req);
    }

    if (r->args) {
        char *arg_copy = apr_pstrdup(r->pool, r->args);

        apr_table_setn(e, "QUERY_STRING", r->args);
        ap_unescape_url(arg_copy);
        apr_table_setn(e, "QUERY_STRING_UNESCAPED", ap_escape_shell_cmd(r->pool, arg_copy));
    }
}

static int include_cmd(include_ctx_t *ctx, ap_filter_t *f,
                       apr_bucket_brigade *bb, char *command)
{
    char **env;
    int sd;
    int retval;
    apr_file_t *tempsock = NULL;
    request_rec *r = f->r;
    cgid_server_conf *conf = ap_get_module_config(r->server->module_config,
                                                  &cgid_module);
    struct cleanup_script_info *info;

    add_ssi_vars(r);
    env = ap_create_environment(r->pool, r->subprocess_env);

    if ((retval = connect_to_daemon(&sd, r, conf)) != OK) {
        return retval;
    }

    send_req(sd, r, command, env, SSI_REQ);

    info = apr_palloc(r->pool, sizeof(struct cleanup_script_info));
    info->r = r;
    info->conn_id = r->connection->id;
    info->conf = conf;
    /* for this type of request, the script is invoked through an
     * intermediate shell process...  cleanup_script is only able
     * to knock out the shell process, not the actual script
     */
    apr_pool_cleanup_register(r->pool, info,
                              cleanup_script,
                              apr_pool_cleanup_null);

    /* We are putting the socket discriptor into an apr_file_t so that we can
     * use a pipe bucket to send the data to the client.  APR will create
     * a cleanup for the apr_file_t which will close the socket, so we'll
     * get rid of the cleanup we registered when we created the socket.
     */
    apr_os_pipe_put_ex(&tempsock, &sd, 1, r->pool);
    apr_pool_cleanup_kill(r->pool, (void *)((long)sd), close_unix_socket);

    APR_BRIGADE_INSERT_TAIL(bb, apr_bucket_pipe_create(tempsock,
                            f->c->bucket_alloc));
    ctx->flush_now = 1;

    return APR_SUCCESS;
}

static apr_status_t handle_exec(include_ctx_t *ctx, ap_filter_t *f,
                                apr_bucket_brigade *bb)
{
    char *tag     = NULL;
    char *tag_val = NULL;
    request_rec *r = f->r;
    char *file = r->filename;
    char parsed_string[MAX_STRING_LEN];

    if (!ctx->argc) {
        ap_log_rerror(APLOG_MARK,
                      (ctx->flags & SSI_FLAG_PRINTING)
                          ? APLOG_ERR : APLOG_WARNING,
                      0, r, "missing argument for exec element in %s",
                      r->filename);
    }

    if (!(ctx->flags & SSI_FLAG_PRINTING)) {
        return APR_SUCCESS;
    }

    if (!ctx->argc) {
        SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
        return APR_SUCCESS;
    }

    if (ctx->flags & SSI_FLAG_NO_EXEC) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "exec used but not allowed "
                      "in %s", r->filename);
        SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
        return APR_SUCCESS;
    }

    while (1) {
        cgid_pfn_gtv(ctx, &tag, &tag_val, SSI_VALUE_DECODED);
        if (!tag || !tag_val) {
            break;
        }

        if (!strcmp(tag, "cmd")) {
            apr_status_t rv;

            cgid_pfn_ps(ctx, tag_val, parsed_string, sizeof(parsed_string),
                        SSI_EXPAND_LEAVE_NAME);

            rv = include_cmd(ctx, f, bb, parsed_string);
            if (rv != APR_SUCCESS) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                              "execution failure for parameter \"%s\" "
                              "to tag exec in file %s", tag, r->filename);
                SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
                break;
            }
        }
        else if (!strcmp(tag, "cgi")) {
            apr_status_t rv;

            cgid_pfn_ps(ctx, tag_val, parsed_string, sizeof(parsed_string),
                        SSI_EXPAND_DROP_NAME);

            rv = include_cgi(ctx, f, bb, parsed_string);
            if (rv != APR_SUCCESS) {
                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "invalid CGI ref "
                              "\"%s\" in %s", tag_val, file);
                SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
                break;
            }
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "unknown parameter "
                          "\"%s\" to tag exec in %s", tag, file);
            SSI_CREATE_ERROR_BUCKET(ctx, f, bb);
            break;
        }
    }

    return APR_SUCCESS;
}
/*============================================================================
 *============================================================================
 * This is the end of the cgi filter code moved from mod_include.
 *============================================================================
 *============================================================================*/


static void register_hook(apr_pool_t *p)
{
    static const char * const aszPre[] = { "mod_include.c", NULL };

    ap_hook_pre_config(cgid_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
    ap_hook_post_config(cgid_init, aszPre, NULL, APR_HOOK_MIDDLE);
    ap_hook_handler(cgid_handler, NULL, NULL, APR_HOOK_MIDDLE);
}

module AP_MODULE_DECLARE_DATA cgid_module = {
    STANDARD20_MODULE_STUFF,
    NULL, /* dir config creater */
    NULL, /* dir merger --- default is to override */
    create_cgid_config, /* server config */
    merge_cgid_config, /* merge server config */
    cgid_cmds, /* command table */
    register_hook /* register_handlers */
};