implement event pattern matching

diff --git a/ubusd_event.c b/ubusd_event.c
index de3687924259e23c372e4a6788aa092b6d4aba9f..a5ff09e87e18e427eaf0d8dd39cd51ec2c9e5b6b 100644 (file)
--- a/ubusd_event.c
+++ b/ubusd_event.c
@@ -4,6 +4,7 @@ static struct avl_tree patterns;
 static LIST_HEAD(catch_all);
 static struct ubus_object *event_obj;
 static int event_seq = 0;
+static int obj_event_seq = 0;
 
 enum evs_type {
        EVS_PATTERN,
@@ -139,11 +140,22 @@ static struct blobmsg_policy ev_policy[] = {
        [EVMSG_DATA] = { .name = "data", .type = BLOBMSG_TYPE_TABLE },
 };
 
-static void ubusd_send_event_msg(struct ubus_msg_buf **ub, struct ubus_object *obj,
-                                const char *id, struct blob_attr *msg)
+static void ubusd_send_event_msg(struct ubus_msg_buf **ub, struct ubus_client *cl,
+                                struct ubus_object *obj, const char *id,
+                                struct blob_attr *msg)
 {
        uint32_t *objid_ptr;
 
+       /* do not loop back events */
+       if (obj->client == cl)
+           return;
+
+       /* do not send duplicate events */
+       if (obj->event_seen == obj_event_seq)
+               return;
+
+       obj->event_seen = obj_event_seq;
+
        if (*ub) {
                objid_ptr = blob_data(blob_data((*ub)->data));
                *objid_ptr = htonl(obj->id.id);
@@ -162,24 +174,61 @@ static void ubusd_send_event_msg(struct ubus_msg_buf **ub, struct ubus_object *o
        ubus_msg_send(obj->client, *ub, false);
 }
 
+bool strmatch_len(const char *s1, const char *s2, int *len)
+{
+       for (*len = 0; s1[*len] == s2[*len]; (*len)++)
+               if (!s1[*len])
+                       return true;
+
+       return false;
+}
+
 static int ubusd_send_event(struct ubus_client *cl, struct blob_attr *msg)
 {
        struct ubus_msg_buf *ub = NULL;
        struct event_source *ev;
        struct blob_attr *attr[EVMSG_LAST];
        const char *id;
+       int match_len = 0;
+       void *data;
 
        blobmsg_parse(ev_policy, EVMSG_LAST, attr, blob_data(msg), blob_len(msg));
        if (!attr[EVMSG_ID] || !attr[EVMSG_DATA])
                return UBUS_STATUS_INVALID_ARGUMENT;
 
        id = blobmsg_data(attr[EVMSG_ID]);
-       list_for_each_entry(ev, &catch_all, catchall.list) {
-               /* do not loop back events */
-               if (ev->obj->client == cl)
-                       continue;
+       data = attr[EVMSG_DATA];
+
+       list_for_each_entry(ev, &catch_all, catchall.list)
+               ubusd_send_event_msg(&ub, cl, ev->obj, id, data);
+
+       obj_event_seq++;
+
+       /*
+        * Since this tree is sorted alphabetically, we can only expect to find
+        * matching entries as long as the number of matching characters
+        * between the pattern string and our string is monotonically increasing.
+        */
+       avl_for_each_element(&patterns, ev, pattern.avl) {
+               const char *key = ev->pattern.avl.key;
+               int cur_match_len;
+               bool full_match;
+
+               full_match = strmatch_len(id, key, &cur_match_len);
+               if (cur_match_len < match_len)
+                       break;
+
+               match_len = cur_match_len;
+
+               if (!full_match) {
+                       if (!ev->pattern.partial)
+                               continue;
+
+                       if (match_len != strlen(key))
+                               continue;
+               }
 
-               ubusd_send_event_msg(&ub, ev->obj, id, attr[EVMSG_DATA]);
+               ubusd_send_event_msg(&ub, cl, ev->obj, id, data);
        }
 
        if (ub)

diff --git a/ubusd_obj.h b/ubusd_obj.h
index b268792b5b556d38eaf89bbb94bb79b605bbe6a2..3fc4937165b9d49135ab58a34932b7e60167b169 100644 (file)
--- a/ubusd_obj.h
+++ b/ubusd_obj.h
@@ -33,6 +33,8 @@ struct ubus_object {
 
        struct ubus_client *client;
        int (*recv_msg)(struct ubus_client *client, const char *method, struct blob_attr *msg);
+
+       int event_seen;
 };
 
 struct ubus_object *ubusd_create_object(struct ubus_client *cl, struct blob_attr **attr);