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, blob_raw_len(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, *tmp;
  44
  45         list_for_each_entry_safe(data, tmp, &req->pending, list) {
  46                 list_del(&data->list);
  47                 if (!req->cancelled)
  48                         req_data_cb(req, data->type, data->data);
  49                 free(data);
  50         }
  51 }
  52
  53 int __hidden __ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  54                                 struct blob_attr *msg, int cmd, uint32_t peer)
  55 {
  56
  57         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
  58                 return -1;
  59
  60         INIT_LIST_HEAD(&req->list);
  61         INIT_LIST_HEAD(&req->pending);
  62         req->ctx = ctx;
  63         req->peer = peer;
  64         req->seq = ++ctx->request_seq;
  65
  66         return ubus_send_msg(ctx, req->seq, msg, cmd, peer, req->fd);
  67 }
  68
  69 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  70                                 struct blob_attr *msg, int cmd, uint32_t peer)
  71 {
  72         memset(req, 0, sizeof(*req));
  73
  74         req->fd = -1;
  75
  76         return __ubus_start_request(ctx, req, msg, cmd, peer);
  77 }
  78
  79
  80 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
  81 {
  82         if (list_empty(&req->list))
  83                 return;
  84
  85         req->cancelled = true;
  86         __ubus_process_req_data(req);
  87         list_del_init(&req->list);
  88 }
  89
  90 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
  91 {
  92         if (!list_empty(&req->list))
  93                 return;
  94
  95         list_add(&req->list, &ctx->requests);
  96 }
  97
  98 static void
  99 ubus_req_complete_cb(struct ubus_request *req)
 100 {
 101         ubus_complete_handler_t cb = req->complete_cb;
 102
 103         if (!cb)
 104                 return;
 105
 106         req->complete_cb = NULL;
 107         cb(req, req->status_code);
 108 }
 109
 110 static void
 111 ubus_set_req_status(struct ubus_request *req, int ret)
 112 {
 113         if (!list_empty(&req->list))
 114                 list_del_init(&req->list);
 115
 116         req->status_msg = true;
 117         req->status_code = ret;
 118         if (!req->blocked)
 119                 ubus_req_complete_cb(req);
 120 }
 121
 122 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 123 {
 124         req->status_msg = true;
 125         req->status_code = ret;
 126         req->ctx->cancel_poll = true;
 127 }
 128
 129 static int64_t get_time_msec(void)
 130 {
 131         struct timespec ts;
 132         int64_t val;
 133
 134         clock_gettime(CLOCK_MONOTONIC, &ts);
 135         val = (int64_t) ts.tv_sec * 1000LL;
 136         val += ts.tv_nsec / 1000000LL;
 137         return val;
 138 }
 139
 140 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 141                           int req_timeout)
 142 {
 143         ubus_complete_handler_t complete_cb = req->complete_cb;
 144         int status = UBUS_STATUS_NO_DATA;
 145         int64_t timeout = 0, time_end = 0;
 146
 147         if (req_timeout)
 148                 time_end = get_time_msec() + req_timeout;
 149
 150         ubus_complete_request_async(ctx, req);
 151         req->complete_cb = ubus_sync_req_cb;
 152
 153         ctx->stack_depth++;
 154         while (!req->status_msg) {
 155                 if (req_timeout) {
 156                         timeout = time_end - get_time_msec();
 157                         if (timeout <= 0) {
 158                                 ubus_set_req_status(req, UBUS_STATUS_TIMEOUT);
 159                                 break;
 160                         }
 161                 }
 162
 163                 ubus_poll_data(ctx, (unsigned int) timeout);
 164
 165                 if (ctx->sock.eof) {
 166                         ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
 167                         ctx->cancel_poll = true;
 168                         break;
 169                 }
 170         }
 171
 172         ctx->stack_depth--;
 173         if (ctx->stack_depth)
 174                 ctx->cancel_poll = true;
 175
 176         if (req->status_msg)
 177                 status = req->status_code;
 178
 179         req->complete_cb = complete_cb;
 180         if (req->complete_cb)
 181                 req->complete_cb(req, status);
 182
 183         if (!ctx->stack_depth && !ctx->sock.registered)
 184                 ctx->pending_timer.cb(&ctx->pending_timer);
 185
 186         return status;
 187 }
 188
 189 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 190 {
 191         blob_buf_init(&b, 0);
 192         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 193         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 194         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
 195 }
 196
 197 static void ubus_put_data(struct blob_buf *buf, struct blob_attr *msg)
 198 {
 199         if (msg)
 200                 blob_put(buf, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 201         else
 202                 blob_put(buf, UBUS_ATTR_DATA, NULL, 0);
 203 }
 204
 205 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 206                     struct blob_attr *msg)
 207 {
 208         int ret;
 209
 210         blob_buf_init(&b, 0);
 211         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 212         ubus_put_data(&b, msg);
 213         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 214         if (ret < 0)
 215                 return UBUS_STATUS_NO_DATA;
 216
 217         return 0;
 218 }
 219
 220 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj,
 221                          const char *method, struct blob_attr *msg,
 222                          struct ubus_request *req, int fd)
 223 {
 224         blob_buf_init(&b, 0);
 225         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 226         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 227         ubus_put_data(&b, msg);
 228
 229         memset(req, 0, sizeof(*req));
 230         req->fd = fd;
 231         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 232                 return UBUS_STATUS_INVALID_ARGUMENT;
 233         return 0;
 234 }
 235
 236 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 237                    struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 238                    int timeout, int fd)
 239 {
 240         struct ubus_request req;
 241         int rc;
 242
 243         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 244         if (rc)
 245                 return rc;
 246
 247         req.data_cb = cb;
 248         req.priv = priv;
 249         return ubus_complete_request(ctx, &req, timeout);
 250 }
 251
 252 static void
 253 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 254 {
 255         struct ubus_notify_request *nreq;
 256
 257         nreq = container_of(req, struct ubus_notify_request, req);
 258         if (!nreq->complete_cb)
 259                 return;
 260
 261         nreq->complete_cb(nreq, 0, 0);
 262 }
 263
 264 static void
 265 ubus_notify_data_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 266 {
 267         struct ubus_notify_request *nreq;
 268
 269         nreq = container_of(req, struct ubus_notify_request, req);
 270         if (!nreq->data_cb)
 271                 return;
 272
 273         nreq->data_cb(nreq, type, msg);
 274 }
 275
 276 static int
 277 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 278                     const char *type, struct blob_attr *msg,
 279                     struct ubus_notify_request *req, bool reply)
 280 {
 281         memset(req, 0, sizeof(*req));
 282
 283         blob_buf_init(&b, 0);
 284         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 285         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 286         ubus_put_data(&b, msg);
 287
 288         if (!reply)
 289                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 290
 291         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 292                 return UBUS_STATUS_INVALID_ARGUMENT;
 293
 294         /* wait for status message from ubusd first */
 295         req->req.notify = true;
 296         req->pending = 1;
 297         req->id[0] = obj->id;
 298         req->req.complete_cb = ubus_notify_complete_cb;
 299         req->req.data_cb = ubus_notify_data_cb;
 300
 301         return 0;
 302 }
 303
 304 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 305                       const char *type, struct blob_attr *msg,
 306                       struct ubus_notify_request *req)
 307 {
 308         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 309 }
 310
 311 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 312                 const char *type, struct blob_attr *msg, int timeout)
 313 {
 314         struct ubus_notify_request req;
 315         int ret;
 316
 317         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 318         if (ret < 0)
 319                 return ret;
 320
 321         if (timeout < 0) {
 322                 ubus_abort_request(ctx, &req.req);
 323                 return 0;
 324         }
 325
 326         return ubus_complete_request(ctx, &req.req, timeout);
 327 }
 328
 329 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 330 {
 331         struct blob_attr **attrbuf = ubus_parse_msg(buf->data, blob_raw_len(buf->data));
 332
 333         if (!attrbuf[UBUS_ATTR_STATUS])
 334                 return false;
 335
 336         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 337         return true;
 338 }
 339
 340 static int
 341 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 342 {
 343         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 344
 345         ubus_get_status(buf, &ret);
 346         req->peer = buf->hdr.peer;
 347         ubus_set_req_status(req, ret);
 348
 349         return ret;
 350 }
 351
 352 static void
 353 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 354 {
 355         struct ubus_pending_data *data;
 356         int len;
 357
 358         if (!req->blocked) {
 359                 req->blocked = true;
 360                 req_data_cb(req, buf->hdr.type, buf->data);
 361                 __ubus_process_req_data(req);
 362                 req->blocked = false;
 363
 364                 if (req->status_msg)
 365                         ubus_req_complete_cb(req);
 366
 367                 return;
 368         }
 369
 370         len = blob_raw_len(buf->data);
 371         data = calloc(1, sizeof(*data) + len);
 372         if (!data)
 373                 return;
 374
 375         data->type = buf->hdr.type;
 376         memcpy(data->data, buf->data, len);
 377         list_add(&data->list, &req->pending);
 378 }
 379
 380 static int
 381 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 382 {
 383         uint32_t pending = n->pending;
 384         int i;
 385
 386         for (i = 0; pending; i++, pending >>= 1) {
 387                 if (!(pending & 1))
 388                         continue;
 389
 390                 if (n->id[i] == objid)
 391                         return i;
 392         }
 393
 394         return -1;
 395 }
 396
 397 static struct ubus_request *
 398 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 399 {
 400         struct ubus_request *req;
 401
 402         list_for_each_entry(req, &ctx->requests, list) {
 403                 struct ubus_notify_request *nreq;
 404                 nreq = container_of(req, struct ubus_notify_request, req);
 405
 406                 if (seq != req->seq)
 407                         continue;
 408
 409                 if (req->notify) {
 410                         if (!nreq->pending)
 411                                 continue;
 412
 413                         *id = ubus_find_notify_id(nreq, peer);
 414                         if (*id < 0)
 415                                 continue;
 416                 } else if (peer != req->peer)
 417                         continue;
 418
 419                 return req;
 420         }
 421         return NULL;
 422 }
 423
 424 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 425 {
 426         struct ubus_notify_request *nreq;
 427         struct blob_attr **tb;
 428         struct blob_attr *cur;
 429         size_t rem;
 430         int idx = 1;
 431         int ret = 0;
 432
 433         nreq = container_of(req, struct ubus_notify_request, req);
 434         nreq->pending &= ~(1 << id);
 435
 436         if (!id) {
 437                 /* first id: ubusd's status message with a list of ids */
 438                 tb = ubus_parse_msg(buf->data, blob_raw_len(buf->data));
 439                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 440                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 441                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 442                                         continue;
 443
 444                                 nreq->pending |= (1 << idx);
 445                                 nreq->id[idx] = blob_get_int32(cur);
 446                                 idx++;
 447
 448                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 449                                         break;
 450                         }
 451                 }
 452         } else {
 453                 ubus_get_status(buf, &ret);
 454                 if (nreq->status_cb)
 455                         nreq->status_cb(nreq, id, ret);
 456         }
 457
 458         if (!nreq->pending)
 459                 ubus_set_req_status(req, 0);
 460 }
 461
 462 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 463 {
 464         struct ubus_msghdr *hdr = &buf->hdr;
 465         struct ubus_request *req;
 466         int id = -1;
 467
 468         switch(hdr->type) {
 469         case UBUS_MSG_STATUS:
 470                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 471                 if (!req)
 472                         break;
 473
 474                 if (fd >= 0) {
 475                         if (req->fd_cb)
 476                                 req->fd_cb(req, fd);
 477                         else
 478                                 close(fd);
 479                 }
 480
 481                 if (id >= 0)
 482                         ubus_process_notify_status(req, id, buf);
 483                 else
 484                         ubus_process_req_status(req, buf);
 485                 break;
 486
 487         case UBUS_MSG_DATA:
 488                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 489                 if (req && (req->data_cb || req->raw_data_cb))
 490                         ubus_process_req_data(req, buf);
 491                 break;
 492         }
 493 }
 494
 495 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 496 {
 497         blob_buf_init(&b, 0);
 498         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 499 }