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 static int event_seq = 0;
   7
   8 enum evs_type {
   9         EVS_PATTERN,
  10         EVS_CATCHALL
  11 };
  12
  13 struct event_source {
  14         struct list_head list;
  15         struct ubus_object *obj;
  16         enum evs_type type;
  17         union {
  18                 struct {
  19                         struct avl_node avl;
  20                 } pattern;
  21                 struct {
  22                         struct list_head list;
  23                 } catchall;
  24         };
  25 };
  26
  27 static void ubusd_delete_event_source(struct event_source *evs)
  28 {
  29         list_del(&evs->list);
  30         switch (evs->type) {
  31         case EVS_PATTERN:
  32                 avl_delete(&patterns, &evs->pattern.avl);
  33                 break;
  34         case EVS_CATCHALL:
  35                 list_del(&evs->catchall.list);
  36                 break;
  37         }
  38         free(evs);
  39 }
  40
  41 void ubusd_event_cleanup_object(struct ubus_object *obj)
  42 {
  43         struct event_source *ev;
  44
  45         while (!list_empty(&obj->events)) {
  46                 ev = list_first_entry(&obj->events, struct event_source, list);
  47                 ubusd_delete_event_source(ev);
  48         }
  49 }
  50
  51 enum {
  52         EVREG_PATTERN,
  53         EVREG_OBJECT,
  54         EVREG_LAST,
  55 };
  56
  57 static struct blobmsg_policy evr_policy[] = {
  58         [EVREG_PATTERN] = { .name = "pattern", .type = BLOBMSG_TYPE_STRING },
  59         [EVREG_OBJECT] = { .name = "object", .type = BLOBMSG_TYPE_INT32 },
  60 };
  61
  62
  63 static struct event_source *ubusd_alloc_event_source(struct ubus_object *obj, enum evs_type type, int datalen)
  64 {
  65         struct event_source *evs;
  66
  67         evs = calloc(1, sizeof(*evs) + datalen);
  68         list_add(&evs->list, &obj->events);
  69         evs->obj = obj;
  70         evs->type = type;
  71         return evs;
  72 }
  73
  74 static int ubusd_alloc_catchall(struct ubus_object *obj)
  75 {
  76         struct event_source *evs;
  77
  78         evs = ubusd_alloc_event_source(obj, EVS_CATCHALL, 0);
  79         list_add(&evs->catchall.list, &catch_all);
  80
  81         return 0;
  82 }
  83
  84 static int ubusd_alloc_event_pattern(struct ubus_client *cl, struct blob_attr *msg)
  85 {
  86         struct event_source *ev;
  87         struct ubus_object *obj;
  88         struct blob_attr *attr[EVREG_LAST];
  89         const char *pattern;
  90         uint32_t id;
  91
  92         blobmsg_parse(evr_policy, EVREG_LAST, attr, blob_data(msg), blob_len(msg));
  93         if (!attr[EVREG_OBJECT])
  94                 return UBUS_STATUS_INVALID_ARGUMENT;
  95
  96         id = blobmsg_get_u32(attr[EVREG_OBJECT]);
  97         if (id < UBUS_SYSTEM_OBJECT_MAX)
  98                 return UBUS_STATUS_PERMISSION_DENIED;
  99
 100         obj = ubusd_find_object(id);
 101         if (!obj)
 102                 return UBUS_STATUS_NOT_FOUND;
 103
 104         if (obj->client != cl)
 105                 return UBUS_STATUS_PERMISSION_DENIED;
 106
 107         if (!attr[EVREG_PATTERN])
 108                 return ubusd_alloc_catchall(obj);
 109
 110         pattern = blobmsg_data(attr[EVREG_PATTERN]);
 111         ev = ubusd_alloc_event_source(obj, EVS_PATTERN, strlen(pattern) + 1);
 112         ev->pattern.avl.key = (void *) (ev + 1);
 113         strcpy(ev->pattern.avl.key, pattern);
 114         avl_insert(&patterns, &ev->pattern.avl);
 115
 116         return 0;
 117 }
 118
 119 enum {
 120         EVMSG_ID,
 121         EVMSG_DATA,
 122         EVMSG_LAST,
 123 };
 124
 125 static struct blobmsg_policy ev_policy[] = {
 126         [EVMSG_ID] = { .name = "id", .type = BLOBMSG_TYPE_STRING },
 127         [EVMSG_DATA] = { .name = "data", .type = BLOBMSG_TYPE_TABLE },
 128 };
 129
 130 static void ubusd_send_event_msg(struct ubus_msg_buf **ub, struct ubus_object *obj,
 131                                  const char *id, struct blob_attr *msg)
 132 {
 133         uint32_t *objid_ptr;
 134
 135         if (*ub) {
 136                 objid_ptr = blob_data(blob_data((*ub)->data));
 137                 *objid_ptr = htonl(obj->id.id);
 138         } else {
 139                 blob_buf_init(&b, 0);
 140                 blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id.id);
 141                 blob_put_string(&b, UBUS_ATTR_METHOD, id);
 142                 blob_put(&b, UBUS_ATTR_DATA, blobmsg_data(msg), blobmsg_data_len(msg));
 143
 144                 *ub = ubus_msg_new(b.head, blob_raw_len(b.head), true);
 145
 146                 (*ub)->hdr.type = UBUS_MSG_INVOKE;
 147                 (*ub)->hdr.peer = 0;
 148         }
 149         (*ub)->hdr.seq = ++event_seq;
 150         ubus_msg_send(obj->client, *ub, false);
 151 }
 152
 153 static int ubusd_send_event(struct ubus_client *cl, struct blob_attr *msg)
 154 {
 155         struct ubus_msg_buf *ub = NULL;
 156         struct event_source *ev;
 157         struct blob_attr *attr[EVMSG_LAST];
 158         const char *id;
 159
 160         blobmsg_parse(ev_policy, EVMSG_LAST, attr, blob_data(msg), blob_len(msg));
 161         if (!attr[EVMSG_ID] || !attr[EVMSG_DATA])
 162                 return UBUS_STATUS_INVALID_ARGUMENT;
 163
 164         id = blobmsg_data(attr[EVMSG_ID]);
 165         list_for_each_entry(ev, &catch_all, catchall.list) {
 166                 /* do not loop back events */
 167                 if (ev->obj->client == cl)
 168                         continue;
 169
 170                 ubusd_send_event_msg(&ub, ev->obj, id, attr[EVMSG_DATA]);
 171         }
 172
 173         if (ub)
 174                 ubus_msg_free(ub);
 175
 176         return 0;
 177 }
 178
 179 static int ubusd_event_recv(struct ubus_client *cl, const char *method, struct blob_attr *msg)
 180 {
 181         if (!strcmp(method, "register"))
 182                 return ubusd_alloc_event_pattern(cl, msg);
 183
 184         if (!strcmp(method, "send"))
 185                 return ubusd_send_event(cl, msg);
 186
 187         return UBUS_STATUS_INVALID_COMMAND;
 188 }
 189
 190 void ubusd_event_init(void)
 191 {
 192         ubus_init_string_tree(&patterns, true);
 193         event_obj = ubusd_create_object_internal(NULL, UBUS_SYSTEM_OBJECT_EVENT);
 194         event_obj->recv_msg = ubusd_event_recv;
 195 }
 196