add support for deferring script requests, limit maximum number of script calls to 3, maximum number of connections to 100

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

1 files changed, 114 insertions, 6 deletions

diff --git a/file.c b/file.c
index 3ac863c..f16b893 100644
--- a/file.c
+++ b/file.c
@@ -34,6 +34,16 @@
 
 static LIST_HEAD(index_files);
 static LIST_HEAD(dispatch_handlers);
+static LIST_HEAD(pending_requests);
+static int n_requests;
+
+struct deferred_request {
+	struct list_head list;
+	struct dispatch_handler *d;
+	struct client *cl;
+	struct path_info pi;
+	bool called, path;
+};
 
 struct index_file {
 	struct list_head list;
@@ -650,6 +660,106 @@ dispatch_find(const char *url, struct path_info *pi)
 	return NULL;
 }
 
+static void
+uh_invoke_script(struct client *cl, struct dispatch_handler *d, struct path_info *pi)
+{
+	char *url = blobmsg_data(blob_data(cl->hdr.head));
+
+	n_requests++;
+	d->handle_request(cl, url, pi);
+}
+
+static void uh_complete_request(struct client *cl)
+{
+	struct deferred_request *dr;
+
+	n_requests--;
+
+	while (!list_empty(&pending_requests)) {
+		if (n_requests >= conf.max_script_requests)
+			return;
+
+		dr = list_first_entry(&pending_requests, struct deferred_request, list);
+		list_del(&dr->list);
+
+		dr->called = true;
+		uh_invoke_script(dr->cl, dr->d, dr->path ? &dr->pi : NULL);
+	}
+}
+
+
+static void
+uh_free_pending_request(struct client *cl)
+{
+	struct deferred_request *dr = cl->dispatch.req_data;
+
+	if (dr->called)
+		uh_complete_request(cl);
+	else
+		list_del(&dr->list);
+	free(dr);
+}
+
+static int field_len(const char *ptr)
+{
+	if (!ptr)
+		return 0;
+
+	return strlen(ptr) + 1;
+}
+
+#define path_info_fields \
+	_field(root) \
+	_field(phys) \
+	_field(name) \
+	_field(info) \
+	_field(query) \
+	_field(auth)
+
+static void
+uh_defer_script(struct client *cl, struct dispatch_handler *d, struct path_info *pi)
+{
+	struct deferred_request *dr;
+	char *_root, *_phys, *_name, *_info, *_query, *_auth;
+
+	cl->dispatch.req_free = uh_free_pending_request;
+
+	if (pi) {
+		/* allocate enough memory to duplicate all path_info strings in one block */
+#undef _field
+#define _field(_name) &_##_name, field_len(pi->_name),
+		dr = calloc_a(sizeof(*dr), path_info_fields NULL);
+
+		memcpy(&dr->pi, pi, sizeof(*pi));
+		dr->path = true;
+
+		/* copy all path_info strings */
+#undef _field
+#define _field(_name) if (pi->_name) dr->pi._name = strcpy(_##_name, pi->_name);
+		path_info_fields
+	} else {
+		dr = calloc(1, sizeof(*dr));
+	}
+
+	cl->dispatch.req_data = dr;
+	dr->cl = cl;
+	dr->d = d;
+	list_add(&dr->list, &pending_requests);
+}
+
+static void
+uh_invoke_handler(struct client *cl, struct dispatch_handler *d, char *url, struct path_info *pi)
+{
+	if (!d->script)
+		return d->handle_request(cl, url, pi);
+
+	if (n_requests >= conf.max_script_requests)
+		return uh_defer_script(cl, d, pi);
+
+	cl->dispatch.req_free = uh_complete_request;
+	uh_invoke_script(cl, d, pi);
+}
+
 static bool __handle_file_request(struct client *cl, char *url)
 {
 	static const struct blobmsg_policy hdr_policy[__HDR_MAX] = {
@@ -680,7 +790,7 @@ static bool __handle_file_request(struct client *cl, char *url)
 
 	d = dispatch_find(url, pi);
 	if (d)
-		d->handle_request(cl, url, pi);
+		uh_invoke_handler(cl, d, url, pi);
 	else
 		uh_file_request(cl, url, pi, tb);
 
@@ -691,15 +801,13 @@ void uh_handle_request(struct client *cl)
 {
 	struct http_request *req = &cl->request;
 	struct dispatch_handler *d;
-	char *url = blobmsg_data(blob_data(cl->hdr.head));;
+	char *url = blobmsg_data(blob_data(cl->hdr.head));
 	char *error_handler;
 
 	req->redirect_status = 200;
 	d = dispatch_find(url, NULL);
-	if (d) {
-		d->handle_request(cl, url, NULL);
-		return;
-	}
+	if (d)
+		return uh_invoke_handler(cl, d, url, NULL);
 
 	if (__handle_file_request(cl, url))
 		return;