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 struct event_pattern {
  28         struct event_source evs;
  29         struct list_head list;
  30 };
  31
  32 struct event_catchall {
  33         struct event_source evs;
  34
  35         struct list_head list;
  36         struct ubus_object *obj;
  37 };
  38
  39 static void ubusd_delete_event_source(struct event_source *evs)
  40 {
  41         list_del(&evs->list);
  42         switch (evs->type) {
  43         case EVS_PATTERN:
  44                 avl_delete(&patterns, &evs->pattern.avl);
  45                 break;
  46         case EVS_CATCHALL:
  47                 list_del(&evs->catchall.list);
  48                 break;
  49         }
  50         free(evs);
  51 }
  52
  53 void ubusd_event_cleanup_object(struct ubus_object *obj)
  54 {
  55         struct event_source *ev;
  56
  57         while (!list_empty(&obj->events)) {
  58                 ev = list_first_entry(&obj->events, struct event_source, list);
  59                 ubusd_delete_event_source(ev);
  60         }
  61 }
  62
  63 enum {
  64         EVREG_PATTERN,
  65         EVREG_OBJECT,
  66         EVREG_LAST,
  67 };
  68
  69 static struct blobmsg_policy evr_policy[] = {
  70         [EVREG_PATTERN] = { .name = "pattern", .type = BLOBMSG_TYPE_STRING },
  71         [EVREG_OBJECT] = { .name = "object", .type = BLOBMSG_TYPE_INT32 },
  72 };
  73
  74
  75 static struct event_source *ubusd_alloc_event_source(struct ubus_object *obj, enum evs_type type, int datalen)
  76 {
  77         struct event_source *evs;
  78
  79         evs = calloc(1, sizeof(*evs) + datalen);
  80         list_add(&evs->list, &obj->events);
  81         evs->obj = obj;
  82         evs->type = type;
  83         return evs;
  84 }
  85
  86 static int ubusd_alloc_catchall(struct ubus_object *obj)
  87 {
  88         struct event_source *evs;
  89
  90         evs = ubusd_alloc_event_source(obj, EVS_CATCHALL, 0);
  91         list_add(&evs->catchall.list, &catch_all);
  92
  93         return 0;
  94 }
  95
  96 static int ubusd_alloc_event_pattern(struct ubus_client *cl, struct blob_attr *msg)
  97 {
  98         struct event_source *ev;
  99         struct ubus_object *obj;
 100         struct blob_attr *attr[EVREG_LAST];
 101         const char *pattern;
 102         uint32_t id;
 103
 104         blobmsg_parse(evr_policy, EVREG_LAST, attr, blob_data(msg), blob_len(msg));
 105         if (!attr[EVREG_OBJECT])
 106                 return UBUS_STATUS_INVALID_ARGUMENT;
 107
 108         id = blobmsg_get_u32(attr[EVREG_OBJECT]);
 109         if (id < UBUS_SYSTEM_OBJECT_MAX)
 110                 return UBUS_STATUS_PERMISSION_DENIED;
 111
 112         obj = ubusd_find_object(id);
 113         if (!obj)
 114                 return UBUS_STATUS_NOT_FOUND;
 115
 116         if (obj->client != cl)
 117                 return UBUS_STATUS_PERMISSION_DENIED;
 118
 119         if (!attr[EVREG_PATTERN])
 120                 return ubusd_alloc_catchall(obj);
 121
 122         pattern = blobmsg_data(attr[EVREG_PATTERN]);
 123         ev = ubusd_alloc_event_source(obj, EVS_PATTERN, strlen(pattern) + 1);
 124         ev->pattern.avl.key = (void *) (ev + 1);
 125         strcpy(ev->pattern.avl.key, pattern);
 126         avl_insert(&patterns, &ev->pattern.avl);
 127
 128         return 0;
 129 }
 130
 131 enum {
 132         EVMSG_ID,
 133         EVMSG_DATA,
 134         EVMSG_LAST,
 135 };
 136
 137 static struct blobmsg_policy ev_policy[] = {
 138         [EVMSG_ID] = { .name = "id", .type = BLOBMSG_TYPE_STRING },
 139         [EVMSG_DATA] = { .name = "data", .type = BLOBMSG_TYPE_TABLE },
 140 };
 141
 142 static void ubusd_send_event_msg(struct ubus_msg_buf **ub, struct ubus_object *obj,
 143                                  const char *id, struct blob_attr *msg)
 144 {
 145         uint32_t *objid_ptr;
 146
 147         if (*ub) {
 148                 objid_ptr = blob_data(blob_data((*ub)->data));
 149                 *objid_ptr = htonl(obj->id.id);
 150         } else {
 151                 blob_buf_init(&b, 0);
 152                 blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id.id);
 153                 blob_put_string(&b, UBUS_ATTR_METHOD, id);
 154                 blob_put(&b, UBUS_ATTR_DATA, blobmsg_data(msg), blobmsg_data_len(msg));
 155
 156                 *ub = ubus_msg_new(b.head, blob_raw_len(b.head), true);
 157
 158                 (*ub)->hdr.type = UBUS_MSG_INVOKE;
 159                 (*ub)->hdr.peer = 0;
 160         }
 161         (*ub)->hdr.seq = ++event_seq;
 162         ubus_msg_send(obj->client, *ub, false);
 163 }
 164
 165 static int ubusd_send_event(struct ubus_client *cl, struct blob_attr *msg)
 166 {
 167         struct ubus_msg_buf *ub = NULL;
 168         struct event_source *ev;
 169         struct blob_attr *attr[EVMSG_LAST];
 170         const char *id;
 171
 172         blobmsg_parse(ev_policy, EVMSG_LAST, attr, blob_data(msg), blob_len(msg));
 173         if (!attr[EVMSG_ID] || !attr[EVMSG_DATA])
 174                 return UBUS_STATUS_INVALID_ARGUMENT;
 175
 176         id = blobmsg_data(attr[EVMSG_ID]);
 177         list_for_each_entry(ev, &catch_all, catchall.list) {
 178                 /* do not loop back events */
 179                 if (ev->obj->client == cl)
 180                         continue;
 181
 182                 ubusd_send_event_msg(&ub, ev->obj, id, attr[EVMSG_DATA]);
 183         }
 184
 185         if (ub)
 186                 ubus_msg_free(ub);
 187
 188         return 0;
 189 }
 190
 191 static int ubusd_event_recv(struct ubus_client *cl, const char *method, struct blob_attr *msg)
 192 {
 193         if (!strcmp(method, "register"))
 194                 return ubusd_alloc_event_pattern(cl, msg);
 195
 196         if (!strcmp(method, "send"))
 197                 return ubusd_send_event(cl, msg);
 198
 199         return UBUS_STATUS_INVALID_COMMAND;
 200 }
 201
 202 void ubusd_event_init(void)
 203 {
 204         ubus_init_string_tree(&patterns, true);
 205         event_obj = ubusd_create_object_internal(NULL, UBUS_SYSTEM_OBJECT_EVENT);
 206         event_obj->recv_msg = ubusd_event_recv;
 207 }
 208