libubus-req.c

   1 /*
   2  * Copyright (C) 2011-2012 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include "libubus.h"
  15 #include "libubus-internal.h"
  16
  17 struct ubus_pending_data {
  18         struct list_head list;
  19         int type;
  20         struct blob_attr data[];
  21 };
  22
  23 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
  24 {
  25         struct blob_attr **attr;
  26
  27         if (req->raw_data_cb)
  28                 req->raw_data_cb(req, type, data);
  29
  30         if (!req->data_cb)
  31                 return;
  32
  33         attr = ubus_parse_msg(data);
  34         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
  35 }
  36
  37 static void __ubus_process_req_data(struct ubus_request *req)
  38 {
  39         struct ubus_pending_data *data;
  40
  41         while (!list_empty(&req->pending)) {
  42                 data = list_first_entry(&req->pending,
  43                         struct ubus_pending_data, list);
  44                 list_del(&data->list);
  45                 if (!req->cancelled)
  46                         req_data_cb(req, data->type, data->data);
  47                 free(data);
  48         }
  49 }
  50
  51 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  52                                 struct blob_attr *msg, int cmd, uint32_t peer)
  53 {
  54         memset(req, 0, sizeof(*req));
  55
  56         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
  57                 return -1;
  58
  59         INIT_LIST_HEAD(&req->list);
  60         INIT_LIST_HEAD(&req->pending);
  61         req->ctx = ctx;
  62         req->peer = peer;
  63         req->seq = ++ctx->request_seq;
  64         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
  65 }
  66
  67 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
  68 {
  69         if (list_empty(&req->list))
  70                 return;
  71
  72         req->cancelled = true;
  73         __ubus_process_req_data(req);
  74         list_del_init(&req->list);
  75 }
  76
  77 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
  78 {
  79         if (!list_empty(&req->list))
  80                 return;
  81
  82         list_add(&req->list, &ctx->requests);
  83 }
  84
  85 static void
  86 ubus_req_complete_cb(struct ubus_request *req)
  87 {
  88         ubus_complete_handler_t cb = req->complete_cb;
  89
  90         if (!cb)
  91                 return;
  92
  93         req->complete_cb = NULL;
  94         cb(req, req->status_code);
  95 }
  96
  97 static void
  98 ubus_set_req_status(struct ubus_request *req, int ret)
  99 {
 100         if (!list_empty(&req->list))
 101                 list_del_init(&req->list);
 102
 103         req->status_msg = true;
 104         req->status_code = ret;
 105         if (!req->blocked)
 106                 ubus_req_complete_cb(req);
 107 }
 108
 109 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 110 {
 111         req->status_msg = true;
 112         req->status_code = ret;
 113         uloop_end();
 114 }
 115
 116 struct ubus_sync_req_cb {
 117         struct uloop_timeout timeout;
 118         struct ubus_request *req;
 119 };
 120
 121 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
 122 {
 123         struct ubus_sync_req_cb *cb;
 124
 125         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 126         ubus_set_req_status(cb->req, UBUS_STATUS_TIMEOUT);
 127 }
 128
 129 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 130                           int timeout)
 131 {
 132         struct ubus_sync_req_cb cb;
 133         ubus_complete_handler_t complete_cb = req->complete_cb;
 134         bool registered = ctx->sock.registered;
 135         int status = UBUS_STATUS_NO_DATA;
 136
 137         if (!registered) {
 138                 uloop_init();
 139                 ubus_add_uloop(ctx);
 140         }
 141
 142         if (timeout) {
 143                 memset(&cb, 0, sizeof(cb));
 144                 cb.req = req;
 145                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 146                 uloop_timeout_set(&cb.timeout, timeout);
 147         }
 148
 149         ubus_complete_request_async(ctx, req);
 150         req->complete_cb = ubus_sync_req_cb;
 151
 152         ctx->stack_depth++;
 153         while (!req->status_msg) {
 154                 bool cancelled = uloop_cancelled;
 155                 uloop_cancelled = false;
 156                 uloop_run();
 157                 uloop_cancelled = cancelled;
 158         }
 159         ctx->stack_depth--;
 160         if (ctx->stack_depth)
 161                 uloop_cancelled = true;
 162
 163         if (timeout)
 164                 uloop_timeout_cancel(&cb.timeout);
 165
 166         if (req->status_msg)
 167                 status = req->status_code;
 168
 169         req->complete_cb = complete_cb;
 170         if (req->complete_cb)
 171                 req->complete_cb(req, status);
 172
 173         if (!registered)
 174                 uloop_fd_delete(&ctx->sock);
 175
 176         if (!ctx->stack_depth)
 177                 ubus_process_pending_msg(ctx);
 178
 179         return status;
 180 }
 181
 182 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 183 {
 184         blob_buf_init(&b, 0);
 185         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 186         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 187         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer);
 188 }
 189
 190 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 191                     struct blob_attr *msg)
 192 {
 193         int ret;
 194
 195         blob_buf_init(&b, 0);
 196         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 197         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 198         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 199         if (ret < 0)
 200                 return UBUS_STATUS_NO_DATA;
 201
 202         return 0;
 203 }
 204
 205 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 206                        struct blob_attr *msg, struct ubus_request *req)
 207 {
 208         blob_buf_init(&b, 0);
 209         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 210         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 211         if (msg)
 212                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 213
 214         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 215                 return UBUS_STATUS_INVALID_ARGUMENT;
 216
 217         return 0;
 218 }
 219
 220 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 221                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 222                 int timeout)
 223 {
 224         struct ubus_request req;
 225
 226         ubus_invoke_async(ctx, obj, method, msg, &req);
 227         req.data_cb = cb;
 228         req.priv = priv;
 229         return ubus_complete_request(ctx, &req, timeout);
 230 }
 231
 232 static void
 233 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 234 {
 235         struct ubus_notify_request *nreq;
 236
 237         nreq = container_of(req, struct ubus_notify_request, req);
 238         if (!nreq->complete_cb)
 239                 return;
 240
 241         nreq->complete_cb(nreq, 0, 0);
 242 }
 243
 244 static int
 245 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 246                     const char *type, struct blob_attr *msg,
 247                     struct ubus_notify_request *req, bool reply)
 248 {
 249         memset(req, 0, sizeof(*req));
 250
 251         blob_buf_init(&b, 0);
 252         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 253         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 254
 255         if (!reply)
 256                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 257
 258         if (msg)
 259                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 260
 261         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 262                 return UBUS_STATUS_INVALID_ARGUMENT;
 263
 264         /* wait for status message from ubusd first */
 265         req->req.notify = true;
 266         req->pending = 1;
 267         req->id[0] = obj->id;
 268         req->req.complete_cb = ubus_notify_complete_cb;
 269
 270         return 0;
 271 }
 272
 273 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 274                       const char *type, struct blob_attr *msg,
 275                       struct ubus_notify_request *req)
 276 {
 277         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 278 }
 279
 280 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 281                 const char *type, struct blob_attr *msg, int timeout)
 282 {
 283         struct ubus_notify_request req;
 284         int ret;
 285
 286         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 287         if (ret < 0)
 288                 return ret;
 289
 290         if (timeout < 0) {
 291                 ubus_abort_request(ctx, &req.req);
 292                 return 0;
 293         }
 294
 295         return ubus_complete_request(ctx, &req.req, timeout);
 296 }
 297
 298 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 299 {
 300         struct blob_attr **attrbuf = ubus_parse_msg(ubus_msghdr_data(hdr));
 301
 302         if (!attrbuf[UBUS_ATTR_STATUS])
 303                 return false;
 304
 305         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 306         return true;
 307 }
 308
 309 static int
 310 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 311 {
 312         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 313
 314         ubus_get_status(hdr, &ret);
 315         req->peer = hdr->peer;
 316         ubus_set_req_status(req, ret);
 317
 318         return ret;
 319 }
 320
 321 static void
 322 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 323 {
 324         struct blob_attr *msg_data = ubus_msghdr_data(hdr);
 325         struct ubus_pending_data *data;
 326         int len;
 327
 328         if (!req->blocked) {
 329                 req->blocked = true;
 330                 req_data_cb(req, hdr->type, msg_data);
 331                 __ubus_process_req_data(req);
 332                 req->blocked = false;
 333
 334                 if (req->status_msg)
 335                         ubus_req_complete_cb(req);
 336
 337                 return;
 338         }
 339
 340         len = blob_raw_len(msg_data);
 341         data = calloc(1, sizeof(*data) + len);
 342         if (!data)
 343                 return;
 344
 345         data->type = hdr->type;
 346         memcpy(data->data, msg_data, len);
 347         list_add(&data->list, &req->pending);
 348 }
 349
 350 static int
 351 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 352 {
 353         uint32_t pending = n->pending;
 354         int i;
 355
 356         for (i = 0; pending; i++, pending >>= 1) {
 357                 if (!(pending & 1))
 358                         continue;
 359
 360                 if (n->id[i] == objid)
 361                         return i;
 362         }
 363
 364         return -1;
 365 }
 366
 367 static struct ubus_request *
 368 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 369 {
 370         struct ubus_request *req;
 371
 372         list_for_each_entry(req, &ctx->requests, list) {
 373                 struct ubus_notify_request *nreq;
 374                 nreq = container_of(req, struct ubus_notify_request, req);
 375
 376                 if (seq != req->seq)
 377                         continue;
 378
 379                 if (req->notify) {
 380                         if (!nreq->pending)
 381                                 continue;
 382
 383                         *id = ubus_find_notify_id(nreq, peer);
 384                         if (*id < 0)
 385                                 continue;
 386                 } else if (peer != req->peer)
 387                         continue;
 388
 389                 return req;
 390         }
 391         return NULL;
 392 }
 393
 394 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr *hdr)
 395 {
 396         struct ubus_notify_request *nreq;
 397         struct blob_attr **tb;
 398         struct blob_attr *cur;
 399         int rem, idx = 1;
 400         int ret = 0;
 401
 402         nreq = container_of(req, struct ubus_notify_request, req);
 403         nreq->pending &= ~(1 << id);
 404
 405         if (!id) {
 406                 /* first id: ubusd's status message with a list of ids */
 407                 tb = ubus_parse_msg(ubus_msghdr_data(hdr));
 408                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 409                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 410                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 411                                         continue;
 412
 413                                 nreq->pending |= (1 << idx);
 414                                 nreq->id[idx] = blob_get_int32(cur);
 415                                 idx++;
 416
 417                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 418                                         break;
 419                         }
 420                 }
 421         } else {
 422                 ubus_get_status(hdr, &ret);
 423                 if (nreq->status_cb)
 424                         nreq->status_cb(nreq, id, ret);
 425         }
 426
 427         if (!nreq->pending)
 428                 ubus_set_req_status(req, 0);
 429 }
 430
 431 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 432 {
 433         struct ubus_request *req;
 434         int id = -1;
 435
 436         switch(hdr->type) {
 437         case UBUS_MSG_STATUS:
 438                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 439                 if (!req)
 440                         break;
 441
 442                 if (id >= 0)
 443                         ubus_process_notify_status(req, id, hdr);
 444                 else
 445                         ubus_process_req_status(req, hdr);
 446                 break;
 447
 448         case UBUS_MSG_DATA:
 449                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 450                 if (req && (req->data_cb || req->raw_data_cb))
 451                         ubus_process_req_data(req, hdr);
 452                 break;
 453         }
 454 }