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         req->ctx->cancel_poll = true;
 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         int status = UBUS_STATUS_NO_DATA;
 144         int64_t timeout = 0, time_end = 0;
 145
 146         if (req_timeout)
 147                 time_end = get_time_msec() + req_timeout;
 148
 149         ubus_complete_request_async(ctx, req);
 150         req->complete_cb = ubus_sync_req_cb;
 151
 152         ctx->stack_depth++;
 153         while (!req->status_msg) {
 154                 if (req_timeout) {
 155                         timeout = time_end - get_time_msec();
 156                         if (timeout <= 0) {
 157                                 ubus_set_req_status(req, UBUS_STATUS_TIMEOUT);
 158                                 break;
 159                         }
 160                 }
 161
 162                 ubus_poll_data(ctx, (unsigned int) timeout);
 163
 164                 if (ctx->sock.eof) {
 165                         ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
 166                         ctx->cancel_poll = true;
 167                         break;
 168                 }
 169         }
 170
 171         ctx->stack_depth--;
 172         if (ctx->stack_depth)
 173                 ctx->cancel_poll = true;
 174
 175         if (req->status_msg)
 176                 status = req->status_code;
 177
 178         req->complete_cb = complete_cb;
 179         if (req->complete_cb)
 180                 req->complete_cb(req, status);
 181
 182         if (!ctx->stack_depth && !ctx->sock.registered)
 183                 ctx->pending_timer.cb(&ctx->pending_timer);
 184
 185         return status;
 186 }
 187
 188 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 189 {
 190         blob_buf_init(&b, 0);
 191         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 192         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 193         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
 194 }
 195
 196 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 197                     struct blob_attr *msg)
 198 {
 199         int ret;
 200
 201         blob_buf_init(&b, 0);
 202         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 203         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 204         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 205         if (ret < 0)
 206                 return UBUS_STATUS_NO_DATA;
 207
 208         return 0;
 209 }
 210
 211 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj,
 212                          const char *method, struct blob_attr *msg,
 213                          struct ubus_request *req, int fd)
 214 {
 215         blob_buf_init(&b, 0);
 216         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 217         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 218         if (msg)
 219                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 220
 221         memset(req, 0, sizeof(*req));
 222         req->fd = fd;
 223         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 224                 return UBUS_STATUS_INVALID_ARGUMENT;
 225         return 0;
 226 }
 227
 228 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 229                    struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 230                    int timeout, int fd)
 231 {
 232         struct ubus_request req;
 233         int rc;
 234
 235         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 236         if (rc)
 237                 return rc;
 238
 239         req.data_cb = cb;
 240         req.priv = priv;
 241         return ubus_complete_request(ctx, &req, timeout);
 242 }
 243
 244 static void
 245 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 246 {
 247         struct ubus_notify_request *nreq;
 248
 249         nreq = container_of(req, struct ubus_notify_request, req);
 250         if (!nreq->complete_cb)
 251                 return;
 252
 253         nreq->complete_cb(nreq, 0, 0);
 254 }
 255
 256 static void
 257 ubus_notify_data_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 258 {
 259         struct ubus_notify_request *nreq;
 260
 261         nreq = container_of(req, struct ubus_notify_request, req);
 262         if (!nreq->data_cb)
 263                 return;
 264
 265         nreq->data_cb(nreq, type, msg);
 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         req->req.data_cb = ubus_notify_data_cb;
 294
 295         return 0;
 296 }
 297
 298 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 299                       const char *type, struct blob_attr *msg,
 300                       struct ubus_notify_request *req)
 301 {
 302         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 303 }
 304
 305 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 306                 const char *type, struct blob_attr *msg, int timeout)
 307 {
 308         struct ubus_notify_request req;
 309         int ret;
 310
 311         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 312         if (ret < 0)
 313                 return ret;
 314
 315         if (timeout < 0) {
 316                 ubus_abort_request(ctx, &req.req);
 317                 return 0;
 318         }
 319
 320         return ubus_complete_request(ctx, &req.req, timeout);
 321 }
 322
 323 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 324 {
 325         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 326
 327         if (!attrbuf[UBUS_ATTR_STATUS])
 328                 return false;
 329
 330         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 331         return true;
 332 }
 333
 334 static int
 335 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 336 {
 337         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 338
 339         ubus_get_status(buf, &ret);
 340         req->peer = buf->hdr.peer;
 341         ubus_set_req_status(req, ret);
 342
 343         return ret;
 344 }
 345
 346 static void
 347 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 348 {
 349         struct ubus_pending_data *data;
 350         int len;
 351
 352         if (!req->blocked) {
 353                 req->blocked = true;
 354                 req_data_cb(req, buf->hdr.type, buf->data);
 355                 __ubus_process_req_data(req);
 356                 req->blocked = false;
 357
 358                 if (req->status_msg)
 359                         ubus_req_complete_cb(req);
 360
 361                 return;
 362         }
 363
 364         len = blob_raw_len(buf->data);
 365         data = calloc(1, sizeof(*data) + len);
 366         if (!data)
 367                 return;
 368
 369         data->type = buf->hdr.type;
 370         memcpy(data->data, buf->data, len);
 371         list_add(&data->list, &req->pending);
 372 }
 373
 374 static int
 375 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 376 {
 377         uint32_t pending = n->pending;
 378         int i;
 379
 380         for (i = 0; pending; i++, pending >>= 1) {
 381                 if (!(pending & 1))
 382                         continue;
 383
 384                 if (n->id[i] == objid)
 385                         return i;
 386         }
 387
 388         return -1;
 389 }
 390
 391 static struct ubus_request *
 392 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 393 {
 394         struct ubus_request *req;
 395
 396         list_for_each_entry(req, &ctx->requests, list) {
 397                 struct ubus_notify_request *nreq;
 398                 nreq = container_of(req, struct ubus_notify_request, req);
 399
 400                 if (seq != req->seq)
 401                         continue;
 402
 403                 if (req->notify) {
 404                         if (!nreq->pending)
 405                                 continue;
 406
 407                         *id = ubus_find_notify_id(nreq, peer);
 408                         if (*id < 0)
 409                                 continue;
 410                 } else if (peer != req->peer)
 411                         continue;
 412
 413                 return req;
 414         }
 415         return NULL;
 416 }
 417
 418 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 419 {
 420         struct ubus_notify_request *nreq;
 421         struct blob_attr **tb;
 422         struct blob_attr *cur;
 423         int rem, idx = 1;
 424         int ret = 0;
 425
 426         nreq = container_of(req, struct ubus_notify_request, req);
 427         nreq->pending &= ~(1 << id);
 428
 429         if (!id) {
 430                 /* first id: ubusd's status message with a list of ids */
 431                 tb = ubus_parse_msg(buf->data);
 432                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 433                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 434                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 435                                         continue;
 436
 437                                 nreq->pending |= (1 << idx);
 438                                 nreq->id[idx] = blob_get_int32(cur);
 439                                 idx++;
 440
 441                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 442                                         break;
 443                         }
 444                 }
 445         } else {
 446                 ubus_get_status(buf, &ret);
 447                 if (nreq->status_cb)
 448                         nreq->status_cb(nreq, id, ret);
 449         }
 450
 451         if (!nreq->pending)
 452                 ubus_set_req_status(req, 0);
 453 }
 454
 455 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 456 {
 457         struct ubus_msghdr *hdr = &buf->hdr;
 458         struct ubus_request *req;
 459         int id = -1;
 460
 461         switch(hdr->type) {
 462         case UBUS_MSG_STATUS:
 463                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 464                 if (!req)
 465                         break;
 466
 467                 if (fd >= 0) {
 468                         if (req->fd_cb)
 469                                 req->fd_cb(req, fd);
 470                         else
 471                                 close(fd);
 472                 }
 473
 474                 if (id >= 0)
 475                         ubus_process_notify_status(req, id, buf);
 476                 else
 477                         ubus_process_req_status(req, buf);
 478                 break;
 479
 480         case UBUS_MSG_DATA:
 481                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 482                 if (req && (req->data_cb || req->raw_data_cb))
 483                         ubus_process_req_data(req, buf);
 484                 break;
 485         }
 486 }
 487
 488 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 489 {
 490         blob_buf_init(&b, 0);
 491         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 492 }