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_fd(struct ubus_context *ctx, uint32_t obj,
 224                          const char *method, struct blob_attr *msg,
 225                          struct ubus_request *req, int fd)
 226 {
 227         blob_buf_init(&b, 0);
 228         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 229         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 230         if (msg)
 231                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 232
 233         memset(req, 0, sizeof(*req));
 234         req->fd = fd;
 235         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 236                 return UBUS_STATUS_INVALID_ARGUMENT;
 237         return 0;
 238 }
 239
 240 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 241                    struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 242                    int timeout, int fd)
 243 {
 244         struct ubus_request req;
 245         int rc;
 246
 247         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 248         if (rc)
 249                 return rc;
 250
 251         req.data_cb = cb;
 252         req.priv = priv;
 253         return ubus_complete_request(ctx, &req, timeout);
 254 }
 255
 256 static void
 257 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 258 {
 259         struct ubus_notify_request *nreq;
 260
 261         nreq = container_of(req, struct ubus_notify_request, req);
 262         if (!nreq->complete_cb)
 263                 return;
 264
 265         nreq->complete_cb(nreq, 0, 0);
 266 }
 267
 268 static int
 269 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 270                     const char *type, struct blob_attr *msg,
 271                     struct ubus_notify_request *req, bool reply)
 272 {
 273         memset(req, 0, sizeof(*req));
 274
 275         blob_buf_init(&b, 0);
 276         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 277         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 278
 279         if (!reply)
 280                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 281
 282         if (msg)
 283                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 284
 285         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 286                 return UBUS_STATUS_INVALID_ARGUMENT;
 287
 288         /* wait for status message from ubusd first */
 289         req->req.notify = true;
 290         req->pending = 1;
 291         req->id[0] = obj->id;
 292         req->req.complete_cb = ubus_notify_complete_cb;
 293
 294         return 0;
 295 }
 296
 297 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 298                       const char *type, struct blob_attr *msg,
 299                       struct ubus_notify_request *req)
 300 {
 301         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 302 }
 303
 304 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 305                 const char *type, struct blob_attr *msg, int timeout)
 306 {
 307         struct ubus_notify_request req;
 308         int ret;
 309
 310         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 311         if (ret < 0)
 312                 return ret;
 313
 314         if (timeout < 0) {
 315                 ubus_abort_request(ctx, &req.req);
 316                 return 0;
 317         }
 318
 319         return ubus_complete_request(ctx, &req.req, timeout);
 320 }
 321
 322 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 323 {
 324         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 325
 326         if (!attrbuf[UBUS_ATTR_STATUS])
 327                 return false;
 328
 329         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 330         return true;
 331 }
 332
 333 static int
 334 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 335 {
 336         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 337
 338         ubus_get_status(buf, &ret);
 339         req->peer = buf->hdr.peer;
 340         ubus_set_req_status(req, ret);
 341
 342         return ret;
 343 }
 344
 345 static void
 346 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 347 {
 348         struct ubus_pending_data *data;
 349         int len;
 350
 351         if (!req->blocked) {
 352                 req->blocked = true;
 353                 req_data_cb(req, buf->hdr.type, buf->data);
 354                 __ubus_process_req_data(req);
 355                 req->blocked = false;
 356
 357                 if (req->status_msg)
 358                         ubus_req_complete_cb(req);
 359
 360                 return;
 361         }
 362
 363         len = blob_raw_len(buf->data);
 364         data = calloc(1, sizeof(*data) + len);
 365         if (!data)
 366                 return;
 367
 368         data->type = buf->hdr.type;
 369         memcpy(data->data, buf->data, len);
 370         list_add(&data->list, &req->pending);
 371 }
 372
 373 static int
 374 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 375 {
 376         uint32_t pending = n->pending;
 377         int i;
 378
 379         for (i = 0; pending; i++, pending >>= 1) {
 380                 if (!(pending & 1))
 381                         continue;
 382
 383                 if (n->id[i] == objid)
 384                         return i;
 385         }
 386
 387         return -1;
 388 }
 389
 390 static struct ubus_request *
 391 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 392 {
 393         struct ubus_request *req;
 394
 395         list_for_each_entry(req, &ctx->requests, list) {
 396                 struct ubus_notify_request *nreq;
 397                 nreq = container_of(req, struct ubus_notify_request, req);
 398
 399                 if (seq != req->seq)
 400                         continue;
 401
 402                 if (req->notify) {
 403                         if (!nreq->pending)
 404                                 continue;
 405
 406                         *id = ubus_find_notify_id(nreq, peer);
 407                         if (*id < 0)
 408                                 continue;
 409                 } else if (peer != req->peer)
 410                         continue;
 411
 412                 return req;
 413         }
 414         return NULL;
 415 }
 416
 417 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 418 {
 419         struct ubus_notify_request *nreq;
 420         struct blob_attr **tb;
 421         struct blob_attr *cur;
 422         int rem, idx = 1;
 423         int ret = 0;
 424
 425         nreq = container_of(req, struct ubus_notify_request, req);
 426         nreq->pending &= ~(1 << id);
 427
 428         if (!id) {
 429                 /* first id: ubusd's status message with a list of ids */
 430                 tb = ubus_parse_msg(buf->data);
 431                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 432                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 433                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 434                                         continue;
 435
 436                                 nreq->pending |= (1 << idx);
 437                                 nreq->id[idx] = blob_get_int32(cur);
 438                                 idx++;
 439
 440                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 441                                         break;
 442                         }
 443                 }
 444         } else {
 445                 ubus_get_status(buf, &ret);
 446                 if (nreq->status_cb)
 447                         nreq->status_cb(nreq, id, ret);
 448         }
 449
 450         if (!nreq->pending)
 451                 ubus_set_req_status(req, 0);
 452 }
 453
 454 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 455 {
 456         struct ubus_msghdr *hdr = &buf->hdr;
 457         struct ubus_request *req;
 458         int id = -1;
 459
 460         switch(hdr->type) {
 461         case UBUS_MSG_STATUS:
 462                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 463                 if (!req)
 464                         break;
 465
 466                 if (fd >= 0) {
 467                         if (req->fd_cb)
 468                                 req->fd_cb(req, fd);
 469                         else
 470                                 close(fd);
 471                 }
 472
 473                 if (id >= 0)
 474                         ubus_process_notify_status(req, id, buf);
 475                 else
 476                         ubus_process_req_status(req, buf);
 477                 break;
 478
 479         case UBUS_MSG_DATA:
 480                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 481                 if (req && (req->data_cb || req->raw_data_cb))
 482                         ubus_process_req_data(req, buf);
 483                 break;
 484         }
 485 }
 486
 487 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 488 {
 489         blob_buf_init(&b, 0);
 490         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 491 }