ubusd_event.c

   1 #include "ubusd.h"
   2
   3 static struct avl_tree patterns;
   4 static LIST_HEAD(catch_all);
   5 static struct ubus_object *event_obj;
   6
   7 enum evs_type {
   8         EVS_PATTERN,
   9         EVS_CATCHALL
  10 };
  11
  12 struct event_source {
  13         struct list_head list;
  14         struct ubus_object *obj;
  15         enum evs_type type;
  16         union {
  17                 struct {
  18                         struct avl_node avl;
  19                 } pattern;
  20                 struct {
  21                         struct list_head list;
  22                 } catchall;
  23         };
  24 };
  25
  26 struct event_pattern {
  27         struct event_source evs;
  28         struct list_head list;
  29 };
  30
  31 struct event_catchall {
  32         struct event_source evs;
  33
  34         struct list_head list;
  35         struct ubus_object *obj;
  36 };
  37
  38 static void ubusd_delete_event_source(struct event_source *evs)
  39 {
  40         list_del(&evs->list);
  41         switch (evs->type) {
  42         case EVS_PATTERN:
  43                 avl_delete(&patterns, &evs->pattern.avl);
  44                 break;
  45         case EVS_CATCHALL:
  46                 list_del(&evs->catchall.list);
  47                 break;
  48         }
  49         free(evs);
  50 }
  51
  52 void ubusd_event_cleanup_object(struct ubus_object *obj)
  53 {
  54         struct event_source *ev;
  55
  56         while (!list_empty(&obj->events)) {
  57                 ev = list_first_entry(&obj->events, struct event_source, list);
  58                 ubusd_delete_event_source(ev);
  59         }
  60 }
  61
  62 enum {
  63         EVMSG_PATTERN,
  64         EVMSG_OBJECT,
  65         EVMSG_LAST,
  66 };
  67
  68 static struct blobmsg_policy ev_policy[] = {
  69         [EVMSG_PATTERN] = { .name = "pattern", .type = BLOBMSG_TYPE_STRING },
  70         [EVMSG_OBJECT] = { .name = "object", .type = BLOBMSG_TYPE_INT32 },
  71 };
  72
  73
  74 static struct event_source *ubusd_alloc_event_source(struct ubus_object *obj, enum evs_type type, int datalen)
  75 {
  76         struct event_source *evs;
  77
  78         evs = calloc(1, sizeof(*evs) + datalen);
  79         list_add(&evs->list, &obj->events);
  80         evs->obj = obj;
  81         evs->type = type;
  82         return evs;
  83 }
  84
  85 static int ubusd_alloc_catchall(struct ubus_object *obj)
  86 {
  87         struct event_source *evs;
  88
  89         evs = ubusd_alloc_event_source(obj, EVS_CATCHALL, 0);
  90         list_add(&evs->catchall.list, &catch_all);
  91
  92         return 0;
  93 }
  94
  95 static int ubusd_alloc_event_pattern(struct ubus_client *cl, struct blob_attr *msg)
  96 {
  97         struct event_source *ev;
  98         struct ubus_object *obj;
  99         struct blob_attr *attr[EVMSG_LAST];
 100         const char *pattern;
 101         uint32_t id;
 102
 103         blobmsg_parse(ev_policy, EVMSG_LAST, attr, blob_data(msg), blob_len(msg));
 104         if (!attr[EVMSG_OBJECT])
 105                 return UBUS_STATUS_INVALID_ARGUMENT;
 106
 107         id = blobmsg_get_u32(attr[EVMSG_OBJECT]);
 108         if (id < UBUS_SYSTEM_OBJECT_MAX)
 109                 return UBUS_STATUS_PERMISSION_DENIED;
 110
 111         obj = ubusd_find_object(id);
 112         if (!obj)
 113                 return UBUS_STATUS_NOT_FOUND;
 114
 115         if (obj->client != cl)
 116                 return UBUS_STATUS_PERMISSION_DENIED;
 117
 118         if (!attr[EVMSG_PATTERN])
 119                 return ubusd_alloc_catchall(obj);
 120
 121         pattern = blobmsg_data(attr[EVMSG_PATTERN]);
 122         ev = ubusd_alloc_event_source(obj, EVS_PATTERN, strlen(pattern) + 1);
 123         ev->pattern.avl.key = (void *) (ev + 1);
 124         strcpy(ev->pattern.avl.key, pattern);
 125         avl_insert(&patterns, &ev->pattern.avl);
 126
 127         return 0;
 128 }
 129
 130 static int ubusd_event_recv(struct ubus_client *cl, const char *method, struct blob_attr *msg)
 131 {
 132         if (!strcmp(method, "register"))
 133                 return ubusd_alloc_event_pattern(cl, msg);
 134
 135         return UBUS_STATUS_INVALID_COMMAND;
 136 }
 137
 138 void ubusd_event_init(void)
 139 {
 140         ubus_init_string_tree(&patterns, true);
 141         event_obj = ubusd_create_object_internal(NULL, UBUS_SYSTEM_OBJECT_EVENT);
 142         event_obj->recv_msg = ubusd_event_recv;
 143 }
 144