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                 ubus_add_uloop(ctx);
 149         }
 150
 151         if (req_timeout)
 152                 time_end = get_time_msec() + req_timeout;
 153
 154         ubus_complete_request_async(ctx, req);
 155         req->complete_cb = ubus_sync_req_cb;
 156
 157         ctx->stack_depth++;
 158         while (!req->status_msg) {
 159                 bool cancelled = uloop_cancelled;
 160
 161                 uloop_cancelled = false;
 162                 if (req_timeout) {
 163                         timeout = time_end - get_time_msec();
 164                         if (timeout <= 0) {
 165                                 ubus_set_req_status(req, UBUS_STATUS_TIMEOUT);
 166                                 uloop_cancelled = cancelled;
 167                                 break;
 168                         }
 169                 }
 170                 ubus_poll_data(ctx, (unsigned int) timeout);
 171
 172                 uloop_cancelled = cancelled;
 173                 if (ctx->sock.eof) {
 174                         ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
 175                         break;
 176                 }
 177         }
 178         ctx->stack_depth--;
 179         if (ctx->stack_depth)
 180                 uloop_cancelled = true;
 181
 182         if (req->status_msg)
 183                 status = req->status_code;
 184
 185         req->complete_cb = complete_cb;
 186         if (req->complete_cb)
 187                 req->complete_cb(req, status);
 188
 189         if (!registered) {
 190                 uloop_fd_delete(&ctx->sock);
 191
 192                 if (!ctx->stack_depth)
 193                         ctx->pending_timer.cb(&ctx->pending_timer);
 194         }
 195
 196         return status;
 197 }
 198
 199 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 200 {
 201         blob_buf_init(&b, 0);
 202         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 203         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 204         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
 205 }
 206
 207 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 208                     struct blob_attr *msg)
 209 {
 210         int ret;
 211
 212         blob_buf_init(&b, 0);
 213         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 214         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 215         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 216         if (ret < 0)
 217                 return UBUS_STATUS_NO_DATA;
 218
 219         return 0;
 220 }
 221
 222 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj,
 223                          const char *method, struct blob_attr *msg,
 224                          struct ubus_request *req, int fd)
 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         memset(req, 0, sizeof(*req));
 233         req->fd = fd;
 234         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 235                 return UBUS_STATUS_INVALID_ARGUMENT;
 236         return 0;
 237 }
 238
 239 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 240                    struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 241                    int timeout, int fd)
 242 {
 243         struct ubus_request req;
 244         int rc;
 245
 246         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 247         if (rc)
 248                 return rc;
 249
 250         req.data_cb = cb;
 251         req.priv = priv;
 252         return ubus_complete_request(ctx, &req, timeout);
 253 }
 254
 255 static void
 256 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 257 {
 258         struct ubus_notify_request *nreq;
 259
 260         nreq = container_of(req, struct ubus_notify_request, req);
 261         if (!nreq->complete_cb)
 262                 return;
 263
 264         nreq->complete_cb(nreq, 0, 0);
 265 }
 266
 267 static int
 268 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 269                     const char *type, struct blob_attr *msg,
 270                     struct ubus_notify_request *req, bool reply)
 271 {
 272         memset(req, 0, sizeof(*req));
 273
 274         blob_buf_init(&b, 0);
 275         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 276         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 277
 278         if (!reply)
 279                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 280
 281         if (msg)
 282                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 283
 284         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 285                 return UBUS_STATUS_INVALID_ARGUMENT;
 286
 287         /* wait for status message from ubusd first */
 288         req->req.notify = true;
 289         req->pending = 1;
 290         req->id[0] = obj->id;
 291         req->req.complete_cb = ubus_notify_complete_cb;
 292
 293         return 0;
 294 }
 295
 296 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 297                       const char *type, struct blob_attr *msg,
 298                       struct ubus_notify_request *req)
 299 {
 300         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 301 }
 302
 303 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 304                 const char *type, struct blob_attr *msg, int timeout)
 305 {
 306         struct ubus_notify_request req;
 307         int ret;
 308
 309         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 310         if (ret < 0)
 311                 return ret;
 312
 313         if (timeout < 0) {
 314                 ubus_abort_request(ctx, &req.req);
 315                 return 0;
 316         }
 317
 318         return ubus_complete_request(ctx, &req.req, timeout);
 319 }
 320
 321 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 322 {
 323         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 324
 325         if (!attrbuf[UBUS_ATTR_STATUS])
 326                 return false;
 327
 328         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 329         return true;
 330 }
 331
 332 static int
 333 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 334 {
 335         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 336
 337         ubus_get_status(buf, &ret);
 338         req->peer = buf->hdr.peer;
 339         ubus_set_req_status(req, ret);
 340
 341         return ret;
 342 }
 343
 344 static void
 345 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 346 {
 347         struct ubus_pending_data *data;
 348         int len;
 349
 350         if (!req->blocked) {
 351                 req->blocked = true;
 352                 req_data_cb(req, buf->hdr.type, buf->data);
 353                 __ubus_process_req_data(req);
 354                 req->blocked = false;
 355
 356                 if (req->status_msg)
 357                         ubus_req_complete_cb(req);
 358
 359                 return;
 360         }
 361
 362         len = blob_raw_len(buf->data);
 363         data = calloc(1, sizeof(*data) + len);
 364         if (!data)
 365                 return;
 366
 367         data->type = buf->hdr.type;
 368         memcpy(data->data, buf->data, len);
 369         list_add(&data->list, &req->pending);
 370 }
 371
 372 static int
 373 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 374 {
 375         uint32_t pending = n->pending;
 376         int i;
 377
 378         for (i = 0; pending; i++, pending >>= 1) {
 379                 if (!(pending & 1))
 380                         continue;
 381
 382                 if (n->id[i] == objid)
 383                         return i;
 384         }
 385
 386         return -1;
 387 }
 388
 389 static struct ubus_request *
 390 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 391 {
 392         struct ubus_request *req;
 393
 394         list_for_each_entry(req, &ctx->requests, list) {
 395                 struct ubus_notify_request *nreq;
 396                 nreq = container_of(req, struct ubus_notify_request, req);
 397
 398                 if (seq != req->seq)
 399                         continue;
 400
 401                 if (req->notify) {
 402                         if (!nreq->pending)
 403                                 continue;
 404
 405                         *id = ubus_find_notify_id(nreq, peer);
 406                         if (*id < 0)
 407                                 continue;
 408                 } else if (peer != req->peer)
 409                         continue;
 410
 411                 return req;
 412         }
 413         return NULL;
 414 }
 415
 416 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 417 {
 418         struct ubus_notify_request *nreq;
 419         struct blob_attr **tb;
 420         struct blob_attr *cur;
 421         int rem, idx = 1;
 422         int ret = 0;
 423
 424         nreq = container_of(req, struct ubus_notify_request, req);
 425         nreq->pending &= ~(1 << id);
 426
 427         if (!id) {
 428                 /* first id: ubusd's status message with a list of ids */
 429                 tb = ubus_parse_msg(buf->data);
 430                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 431                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 432                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 433                                         continue;
 434
 435                                 nreq->pending |= (1 << idx);
 436                                 nreq->id[idx] = blob_get_int32(cur);
 437                                 idx++;
 438
 439                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 440                                         break;
 441                         }
 442                 }
 443         } else {
 444                 ubus_get_status(buf, &ret);
 445                 if (nreq->status_cb)
 446                         nreq->status_cb(nreq, id, ret);
 447         }
 448
 449         if (!nreq->pending)
 450                 ubus_set_req_status(req, 0);
 451 }
 452
 453 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 454 {
 455         struct ubus_msghdr *hdr = &buf->hdr;
 456         struct ubus_request *req;
 457         int id = -1;
 458
 459         switch(hdr->type) {
 460         case UBUS_MSG_STATUS:
 461                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 462                 if (!req)
 463                         break;
 464
 465                 if (fd >= 0) {
 466                         if (req->fd_cb)
 467                                 req->fd_cb(req, fd);
 468                         else
 469                                 close(fd);
 470                 }
 471
 472                 if (id >= 0)
 473                         ubus_process_notify_status(req, id, buf);
 474                 else
 475                         ubus_process_req_status(req, buf);
 476                 break;
 477
 478         case UBUS_MSG_DATA:
 479                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 480                 if (req && (req->data_cb || req->raw_data_cb))
 481                         ubus_process_req_data(req, buf);
 482                 break;
 483         }
 484 }
 485
 486 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 487 {
 488         blob_buf_init(&b, 0);
 489         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 490 }