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         if (!attr[UBUS_ATTR_DATA])
  36                 return;
  37
  38         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
  39 }
  40
  41 static void __ubus_process_req_data(struct ubus_request *req)
  42 {
  43         struct ubus_pending_data *data;
  44
  45         while (!list_empty(&req->pending)) {
  46                 data = list_first_entry(&req->pending,
  47                         struct ubus_pending_data, list);
  48                 list_del(&data->list);
  49                 if (!req->cancelled)
  50                         req_data_cb(req, data->type, data->data);
  51                 free(data);
  52         }
  53 }
  54
  55 int __hidden __ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  56                                 struct blob_attr *msg, int cmd, uint32_t peer)
  57 {
  58
  59         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
  60                 return -1;
  61
  62         INIT_LIST_HEAD(&req->list);
  63         INIT_LIST_HEAD(&req->pending);
  64         req->ctx = ctx;
  65         req->peer = peer;
  66         req->seq = ++ctx->request_seq;
  67
  68         return ubus_send_msg(ctx, req->seq, msg, cmd, peer, req->fd);
  69 }
  70
  71 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  72                                 struct blob_attr *msg, int cmd, uint32_t peer)
  73 {
  74         memset(req, 0, sizeof(*req));
  75
  76         req->fd = -1;
  77
  78         return __ubus_start_request(ctx, req, msg, cmd, peer);
  79 }
  80
  81
  82 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
  83 {
  84         if (list_empty(&req->list))
  85                 return;
  86
  87         req->cancelled = true;
  88         __ubus_process_req_data(req);
  89         list_del_init(&req->list);
  90 }
  91
  92 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
  93 {
  94         if (!list_empty(&req->list))
  95                 return;
  96
  97         list_add(&req->list, &ctx->requests);
  98 }
  99
 100 static void
 101 ubus_req_complete_cb(struct ubus_request *req)
 102 {
 103         ubus_complete_handler_t cb = req->complete_cb;
 104
 105         if (!cb)
 106                 return;
 107
 108         req->complete_cb = NULL;
 109         cb(req, req->status_code);
 110 }
 111
 112 static void
 113 ubus_set_req_status(struct ubus_request *req, int ret)
 114 {
 115         if (!list_empty(&req->list))
 116                 list_del_init(&req->list);
 117
 118         req->status_msg = true;
 119         req->status_code = ret;
 120         if (!req->blocked)
 121                 ubus_req_complete_cb(req);
 122 }
 123
 124 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 125 {
 126         req->status_msg = true;
 127         req->status_code = ret;
 128         req->ctx->cancel_poll = true;
 129 }
 130
 131 static int64_t get_time_msec(void)
 132 {
 133         struct timespec ts;
 134         int64_t val;
 135
 136         clock_gettime(CLOCK_MONOTONIC, &ts);
 137         val = (int64_t) ts.tv_sec * 1000LL;
 138         val += ts.tv_nsec / 1000000LL;
 139         return val;
 140 }
 141
 142 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 143                           int req_timeout)
 144 {
 145         ubus_complete_handler_t complete_cb = req->complete_cb;
 146         int status = UBUS_STATUS_NO_DATA;
 147         int64_t timeout = 0, time_end = 0;
 148
 149         if (req_timeout)
 150                 time_end = get_time_msec() + req_timeout;
 151
 152         ubus_complete_request_async(ctx, req);
 153         req->complete_cb = ubus_sync_req_cb;
 154
 155         ctx->stack_depth++;
 156         while (!req->status_msg) {
 157                 if (req_timeout) {
 158                         timeout = time_end - get_time_msec();
 159                         if (timeout <= 0) {
 160                                 ubus_set_req_status(req, UBUS_STATUS_TIMEOUT);
 161                                 break;
 162                         }
 163                 }
 164
 165                 ubus_poll_data(ctx, (unsigned int) timeout);
 166
 167                 if (ctx->sock.eof) {
 168                         ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
 169                         ctx->cancel_poll = true;
 170                         break;
 171                 }
 172         }
 173
 174         ctx->stack_depth--;
 175         if (ctx->stack_depth)
 176                 ctx->cancel_poll = true;
 177
 178         if (req->status_msg)
 179                 status = req->status_code;
 180
 181         req->complete_cb = complete_cb;
 182         if (req->complete_cb)
 183                 req->complete_cb(req, status);
 184
 185         if (!ctx->stack_depth && !ctx->sock.registered)
 186                 ctx->pending_timer.cb(&ctx->pending_timer);
 187
 188         return status;
 189 }
 190
 191 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 192 {
 193         blob_buf_init(&b, 0);
 194         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 195         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 196         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
 197 }
 198
 199 static void ubus_put_data(struct blob_buf *buf, struct blob_attr *msg)
 200 {
 201         if (msg)
 202                 blob_put(buf, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 203         else
 204                 blob_put(buf, UBUS_ATTR_DATA, NULL, 0);
 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         ubus_put_data(&b, 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         ubus_put_data(&b, msg);
 230
 231         memset(req, 0, sizeof(*req));
 232         req->fd = fd;
 233         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 234                 return UBUS_STATUS_INVALID_ARGUMENT;
 235         return 0;
 236 }
 237
 238 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 239                    struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 240                    int timeout, int fd)
 241 {
 242         struct ubus_request req;
 243         int rc;
 244
 245         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 246         if (rc)
 247                 return rc;
 248
 249         req.data_cb = cb;
 250         req.priv = priv;
 251         return ubus_complete_request(ctx, &req, timeout);
 252 }
 253
 254 static void
 255 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 256 {
 257         struct ubus_notify_request *nreq;
 258
 259         nreq = container_of(req, struct ubus_notify_request, req);
 260         if (!nreq->complete_cb)
 261                 return;
 262
 263         nreq->complete_cb(nreq, 0, 0);
 264 }
 265
 266 static void
 267 ubus_notify_data_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 268 {
 269         struct ubus_notify_request *nreq;
 270
 271         nreq = container_of(req, struct ubus_notify_request, req);
 272         if (!nreq->data_cb)
 273                 return;
 274
 275         nreq->data_cb(nreq, type, msg);
 276 }
 277
 278 static int
 279 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 280                     const char *type, struct blob_attr *msg,
 281                     struct ubus_notify_request *req, bool reply)
 282 {
 283         memset(req, 0, sizeof(*req));
 284
 285         blob_buf_init(&b, 0);
 286         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 287         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 288         ubus_put_data(&b, msg);
 289
 290         if (!reply)
 291                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 292
 293         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 294                 return UBUS_STATUS_INVALID_ARGUMENT;
 295
 296         /* wait for status message from ubusd first */
 297         req->req.notify = true;
 298         req->pending = 1;
 299         req->id[0] = obj->id;
 300         req->req.complete_cb = ubus_notify_complete_cb;
 301         req->req.data_cb = ubus_notify_data_cb;
 302
 303         return 0;
 304 }
 305
 306 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 307                       const char *type, struct blob_attr *msg,
 308                       struct ubus_notify_request *req)
 309 {
 310         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 311 }
 312
 313 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 314                 const char *type, struct blob_attr *msg, int timeout)
 315 {
 316         struct ubus_notify_request req;
 317         int ret;
 318
 319         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 320         if (ret < 0)
 321                 return ret;
 322
 323         if (timeout < 0) {
 324                 ubus_abort_request(ctx, &req.req);
 325                 return 0;
 326         }
 327
 328         return ubus_complete_request(ctx, &req.req, timeout);
 329 }
 330
 331 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 332 {
 333         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 334
 335         if (!attrbuf[UBUS_ATTR_STATUS])
 336                 return false;
 337
 338         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 339         return true;
 340 }
 341
 342 static int
 343 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 344 {
 345         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 346
 347         ubus_get_status(buf, &ret);
 348         req->peer = buf->hdr.peer;
 349         ubus_set_req_status(req, ret);
 350
 351         return ret;
 352 }
 353
 354 static void
 355 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 356 {
 357         struct ubus_pending_data *data;
 358         int len;
 359
 360         if (!req->blocked) {
 361                 req->blocked = true;
 362                 req_data_cb(req, buf->hdr.type, buf->data);
 363                 __ubus_process_req_data(req);
 364                 req->blocked = false;
 365
 366                 if (req->status_msg)
 367                         ubus_req_complete_cb(req);
 368
 369                 return;
 370         }
 371
 372         len = blob_raw_len(buf->data);
 373         data = calloc(1, sizeof(*data) + len);
 374         if (!data)
 375                 return;
 376
 377         data->type = buf->hdr.type;
 378         memcpy(data->data, buf->data, len);
 379         list_add(&data->list, &req->pending);
 380 }
 381
 382 static int
 383 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 384 {
 385         uint32_t pending = n->pending;
 386         int i;
 387
 388         for (i = 0; pending; i++, pending >>= 1) {
 389                 if (!(pending & 1))
 390                         continue;
 391
 392                 if (n->id[i] == objid)
 393                         return i;
 394         }
 395
 396         return -1;
 397 }
 398
 399 static struct ubus_request *
 400 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 401 {
 402         struct ubus_request *req;
 403
 404         list_for_each_entry(req, &ctx->requests, list) {
 405                 struct ubus_notify_request *nreq;
 406                 nreq = container_of(req, struct ubus_notify_request, req);
 407
 408                 if (seq != req->seq)
 409                         continue;
 410
 411                 if (req->notify) {
 412                         if (!nreq->pending)
 413                                 continue;
 414
 415                         *id = ubus_find_notify_id(nreq, peer);
 416                         if (*id < 0)
 417                                 continue;
 418                 } else if (peer != req->peer)
 419                         continue;
 420
 421                 return req;
 422         }
 423         return NULL;
 424 }
 425
 426 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 427 {
 428         struct ubus_notify_request *nreq;
 429         struct blob_attr **tb;
 430         struct blob_attr *cur;
 431         int rem, idx = 1;
 432         int ret = 0;
 433
 434         nreq = container_of(req, struct ubus_notify_request, req);
 435         nreq->pending &= ~(1 << id);
 436
 437         if (!id) {
 438                 /* first id: ubusd's status message with a list of ids */
 439                 tb = ubus_parse_msg(buf->data);
 440                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 441                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 442                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 443                                         continue;
 444
 445                                 nreq->pending |= (1 << idx);
 446                                 nreq->id[idx] = blob_get_int32(cur);
 447                                 idx++;
 448
 449                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 450                                         break;
 451                         }
 452                 }
 453         } else {
 454                 ubus_get_status(buf, &ret);
 455                 if (nreq->status_cb)
 456                         nreq->status_cb(nreq, id, ret);
 457         }
 458
 459         if (!nreq->pending)
 460                 ubus_set_req_status(req, 0);
 461 }
 462
 463 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 464 {
 465         struct ubus_msghdr *hdr = &buf->hdr;
 466         struct ubus_request *req;
 467         int id = -1;
 468
 469         switch(hdr->type) {
 470         case UBUS_MSG_STATUS:
 471                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 472                 if (!req)
 473                         break;
 474
 475                 if (fd >= 0) {
 476                         if (req->fd_cb)
 477                                 req->fd_cb(req, fd);
 478                         else
 479                                 close(fd);
 480                 }
 481
 482                 if (id >= 0)
 483                         ubus_process_notify_status(req, id, buf);
 484                 else
 485                         ubus_process_req_status(req, buf);
 486                 break;
 487
 488         case UBUS_MSG_DATA:
 489                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 490                 if (req && (req->data_cb || req->raw_data_cb))
 491                         ubus_process_req_data(req, buf);
 492                 break;
 493         }
 494 }
 495
 496 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 497 {
 498         blob_buf_init(&b, 0);
 499         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 500 }