libubus-req.c

   1 /*
   2  * Copyright (C) 2011-2014 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 <unistd.h>
  15 #include "libubus.h"
  16 #include "libubus-internal.h"
  17
  18 struct ubus_pending_data {
  19         struct list_head list;
  20         int type;
  21         struct blob_attr data[];
  22 };
  23
  24 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
  25 {
  26         struct blob_attr **attr;
  27
  28         if (req->raw_data_cb)
  29                 req->raw_data_cb(req, type, data);
  30
  31         if (!req->data_cb)
  32                 return;
  33
  34         attr = ubus_parse_msg(data);
  35         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
  36 }
  37
  38 static void __ubus_process_req_data(struct ubus_request *req)
  39 {
  40         struct ubus_pending_data *data;
  41
  42         while (!list_empty(&req->pending)) {
  43                 data = list_first_entry(&req->pending,
  44                         struct ubus_pending_data, list);
  45                 list_del(&data->list);
  46                 if (!req->cancelled)
  47                         req_data_cb(req, data->type, data->data);
  48                 free(data);
  49         }
  50 }
  51
  52 int __hidden __ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  53                                 struct blob_attr *msg, int cmd, uint32_t peer)
  54 {
  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
  65         return ubus_send_msg(ctx, req->seq, msg, cmd, peer, req->fd);
  66 }
  67
  68 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  69                                 struct blob_attr *msg, int cmd, uint32_t peer)
  70 {
  71         memset(req, 0, sizeof(*req));
  72
  73         req->fd = -1;
  74
  75         return __ubus_start_request(ctx, req, msg, cmd, peer);
  76 }
  77
  78
  79 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
  80 {
  81         if (list_empty(&req->list))
  82                 return;
  83
  84         req->cancelled = true;
  85         __ubus_process_req_data(req);
  86         list_del_init(&req->list);
  87 }
  88
  89 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
  90 {
  91         if (!list_empty(&req->list))
  92                 return;
  93
  94         list_add(&req->list, &ctx->requests);
  95 }
  96
  97 static void
  98 ubus_req_complete_cb(struct ubus_request *req)
  99 {
 100         ubus_complete_handler_t cb = req->complete_cb;
 101
 102         if (!cb)
 103                 return;
 104
 105         req->complete_cb = NULL;
 106         cb(req, req->status_code);
 107 }
 108
 109 static void
 110 ubus_set_req_status(struct ubus_request *req, int ret)
 111 {
 112         if (!list_empty(&req->list))
 113                 list_del_init(&req->list);
 114
 115         req->status_msg = true;
 116         req->status_code = ret;
 117         if (!req->blocked)
 118                 ubus_req_complete_cb(req);
 119 }
 120
 121 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 122 {
 123         req->status_msg = true;
 124         req->status_code = ret;
 125         uloop_end();
 126 }
 127
 128 static int64_t get_time_msec(void)
 129 {
 130         struct timespec ts;
 131         int64_t val;
 132
 133         clock_gettime(CLOCK_MONOTONIC, &ts);
 134         val = (int64_t) ts.tv_sec * 1000LL;
 135         val += ts.tv_nsec / 1000000LL;
 136         return val;
 137 }
 138
 139 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 140                           int req_timeout)
 141 {
 142         ubus_complete_handler_t complete_cb = req->complete_cb;
 143         bool registered = ctx->sock.registered;
 144         int status = UBUS_STATUS_NO_DATA;
 145         int64_t timeout = 0, time_end = 0;
 146
 147         if (!registered) {
 148                 uloop_init();
 149                 ubus_add_uloop(ctx);
 150         }
 151
 152         if (req_timeout)
 153                 time_end = get_time_msec() + req_timeout;
 154
 155         ubus_complete_request_async(ctx, req);
 156         req->complete_cb = ubus_sync_req_cb;
 157
 158         ctx->stack_depth++;
 159         while (!req->status_msg) {
 160                 bool cancelled = uloop_cancelled;
 161
 162                 uloop_cancelled = false;
 163                 if (req_timeout) {
 164                         timeout = time_end - get_time_msec();
 165                         if (timeout <= 0) {
 166                                 ubus_set_req_status(req, UBUS_STATUS_TIMEOUT);
 167                                 uloop_cancelled = cancelled;
 168                                 break;
 169                         }
 170                 }
 171                 ubus_poll_data(ctx, (unsigned int) timeout);
 172
 173                 uloop_cancelled = cancelled;
 174                 if (ctx->sock.eof) {
 175                         ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
 176                         break;
 177                 }
 178         }
 179         ctx->stack_depth--;
 180         if (ctx->stack_depth)
 181                 uloop_cancelled = true;
 182
 183         if (req->status_msg)
 184                 status = req->status_code;
 185
 186         req->complete_cb = complete_cb;
 187         if (req->complete_cb)
 188                 req->complete_cb(req, status);
 189
 190         if (!registered) {
 191                 uloop_fd_delete(&ctx->sock);
 192
 193                 if (!ctx->stack_depth)
 194                         ctx->pending_timer.cb(&ctx->pending_timer);
 195         }
 196
 197         return status;
 198 }
 199
 200 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 201 {
 202         blob_buf_init(&b, 0);
 203         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 204         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 205         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
 206 }
 207
 208 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 209                     struct blob_attr *msg)
 210 {
 211         int ret;
 212
 213         blob_buf_init(&b, 0);
 214         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 215         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 216         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 217         if (ret < 0)
 218                 return UBUS_STATUS_NO_DATA;
 219
 220         return 0;
 221 }
 222
 223 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 224                        struct blob_attr *msg, struct ubus_request *req)
 225 {
 226         blob_buf_init(&b, 0);
 227         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 228         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 229         if (msg)
 230                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 231
 232         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 233                 return UBUS_STATUS_INVALID_ARGUMENT;
 234
 235         return 0;
 236 }
 237
 238
 239 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 240                        struct blob_attr *msg, struct ubus_request *req, int fd)
 241 {
 242         blob_buf_init(&b, 0);
 243         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 244         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 245         if (msg)
 246                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 247
 248         memset(req, 0, sizeof(*req));
 249         req->fd = fd;
 250         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 251                 return UBUS_STATUS_INVALID_ARGUMENT;
 252         return 0;
 253 }
 254
 255 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 256                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 257                 int timeout)
 258 {
 259         struct ubus_request req;
 260         int rc;
 261
 262         rc = ubus_invoke_async(ctx, obj, method, msg, &req);
 263         if (rc)
 264                 return rc;
 265
 266         req.data_cb = cb;
 267         req.priv = priv;
 268         return ubus_complete_request(ctx, &req, timeout);
 269 }
 270
 271 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 272                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 273                 int timeout, int fd)
 274 {
 275         struct ubus_request req;
 276         int rc;
 277
 278         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 279         if (rc)
 280                 return rc;
 281
 282         req.data_cb = cb;
 283         req.priv = priv;
 284         return ubus_complete_request(ctx, &req, timeout);
 285 }
 286
 287 static void
 288 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 289 {
 290         struct ubus_notify_request *nreq;
 291
 292         nreq = container_of(req, struct ubus_notify_request, req);
 293         if (!nreq->complete_cb)
 294                 return;
 295
 296         nreq->complete_cb(nreq, 0, 0);
 297 }
 298
 299 static int
 300 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 301                     const char *type, struct blob_attr *msg,
 302                     struct ubus_notify_request *req, bool reply)
 303 {
 304         memset(req, 0, sizeof(*req));
 305
 306         blob_buf_init(&b, 0);
 307         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 308         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 309
 310         if (!reply)
 311                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 312
 313         if (msg)
 314                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 315
 316         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 317                 return UBUS_STATUS_INVALID_ARGUMENT;
 318
 319         /* wait for status message from ubusd first */
 320         req->req.notify = true;
 321         req->pending = 1;
 322         req->id[0] = obj->id;
 323         req->req.complete_cb = ubus_notify_complete_cb;
 324
 325         return 0;
 326 }
 327
 328 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 329                       const char *type, struct blob_attr *msg,
 330                       struct ubus_notify_request *req)
 331 {
 332         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 333 }
 334
 335 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 336                 const char *type, struct blob_attr *msg, int timeout)
 337 {
 338         struct ubus_notify_request req;
 339         int ret;
 340
 341         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 342         if (ret < 0)
 343                 return ret;
 344
 345         if (timeout < 0) {
 346                 ubus_abort_request(ctx, &req.req);
 347                 return 0;
 348         }
 349
 350         return ubus_complete_request(ctx, &req.req, timeout);
 351 }
 352
 353 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 354 {
 355         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 356
 357         if (!attrbuf[UBUS_ATTR_STATUS])
 358                 return false;
 359
 360         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 361         return true;
 362 }
 363
 364 static int
 365 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 366 {
 367         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 368
 369         ubus_get_status(buf, &ret);
 370         req->peer = buf->hdr.peer;
 371         ubus_set_req_status(req, ret);
 372
 373         return ret;
 374 }
 375
 376 static void
 377 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 378 {
 379         struct ubus_pending_data *data;
 380         int len;
 381
 382         if (!req->blocked) {
 383                 req->blocked = true;
 384                 req_data_cb(req, buf->hdr.type, buf->data);
 385                 __ubus_process_req_data(req);
 386                 req->blocked = false;
 387
 388                 if (req->status_msg)
 389                         ubus_req_complete_cb(req);
 390
 391                 return;
 392         }
 393
 394         len = blob_raw_len(buf->data);
 395         data = calloc(1, sizeof(*data) + len);
 396         if (!data)
 397                 return;
 398
 399         data->type = buf->hdr.type;
 400         memcpy(data->data, buf->data, len);
 401         list_add(&data->list, &req->pending);
 402 }
 403
 404 static int
 405 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 406 {
 407         uint32_t pending = n->pending;
 408         int i;
 409
 410         for (i = 0; pending; i++, pending >>= 1) {
 411                 if (!(pending & 1))
 412                         continue;
 413
 414                 if (n->id[i] == objid)
 415                         return i;
 416         }
 417
 418         return -1;
 419 }
 420
 421 static struct ubus_request *
 422 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 423 {
 424         struct ubus_request *req;
 425
 426         list_for_each_entry(req, &ctx->requests, list) {
 427                 struct ubus_notify_request *nreq;
 428                 nreq = container_of(req, struct ubus_notify_request, req);
 429
 430                 if (seq != req->seq)
 431                         continue;
 432
 433                 if (req->notify) {
 434                         if (!nreq->pending)
 435                                 continue;
 436
 437                         *id = ubus_find_notify_id(nreq, peer);
 438                         if (*id < 0)
 439                                 continue;
 440                 } else if (peer != req->peer)
 441                         continue;
 442
 443                 return req;
 444         }
 445         return NULL;
 446 }
 447
 448 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 449 {
 450         struct ubus_notify_request *nreq;
 451         struct blob_attr **tb;
 452         struct blob_attr *cur;
 453         int rem, idx = 1;
 454         int ret = 0;
 455
 456         nreq = container_of(req, struct ubus_notify_request, req);
 457         nreq->pending &= ~(1 << id);
 458
 459         if (!id) {
 460                 /* first id: ubusd's status message with a list of ids */
 461                 tb = ubus_parse_msg(buf->data);
 462                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 463                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 464                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 465                                         continue;
 466
 467                                 nreq->pending |= (1 << idx);
 468                                 nreq->id[idx] = blob_get_int32(cur);
 469                                 idx++;
 470
 471                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 472                                         break;
 473                         }
 474                 }
 475         } else {
 476                 ubus_get_status(buf, &ret);
 477                 if (nreq->status_cb)
 478                         nreq->status_cb(nreq, id, ret);
 479         }
 480
 481         if (!nreq->pending)
 482                 ubus_set_req_status(req, 0);
 483 }
 484
 485 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 486 {
 487         struct ubus_msghdr *hdr = &buf->hdr;
 488         struct ubus_request *req;
 489         int id = -1;
 490
 491         switch(hdr->type) {
 492         case UBUS_MSG_STATUS:
 493                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 494                 if (!req)
 495                         break;
 496
 497                 if (fd >= 0) {
 498                         if (req->fd_cb)
 499                                 req->fd_cb(req, fd);
 500                         else
 501                                 close(fd);
 502                 }
 503
 504                 if (id >= 0)
 505                         ubus_process_notify_status(req, id, buf);
 506                 else
 507                         ubus_process_req_status(req, buf);
 508                 break;
 509
 510         case UBUS_MSG_DATA:
 511                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 512                 if (req && (req->data_cb || req->raw_data_cb))
 513                         ubus_process_req_data(req, buf);
 514                 break;
 515         }
 516 }
 517
 518 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 519 {
 520         blob_buf_init(&b, 0);
 521         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 522 }