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 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 200                     struct blob_attr *msg)
 201 {
 202         int ret;
 203
 204         blob_buf_init(&b, 0);
 205         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 206         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 207         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 208         if (ret < 0)
 209                 return UBUS_STATUS_NO_DATA;
 210
 211         return 0;
 212 }
 213
 214 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj,
 215                          const char *method, struct blob_attr *msg,
 216                          struct ubus_request *req, int fd)
 217 {
 218         blob_buf_init(&b, 0);
 219         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 220         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 221         if (msg)
 222                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 223
 224         memset(req, 0, sizeof(*req));
 225         req->fd = fd;
 226         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 227                 return UBUS_STATUS_INVALID_ARGUMENT;
 228         return 0;
 229 }
 230
 231 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 232                    struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 233                    int timeout, int fd)
 234 {
 235         struct ubus_request req;
 236         int rc;
 237
 238         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 239         if (rc)
 240                 return rc;
 241
 242         req.data_cb = cb;
 243         req.priv = priv;
 244         return ubus_complete_request(ctx, &req, timeout);
 245 }
 246
 247 static void
 248 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 249 {
 250         struct ubus_notify_request *nreq;
 251
 252         nreq = container_of(req, struct ubus_notify_request, req);
 253         if (!nreq->complete_cb)
 254                 return;
 255
 256         nreq->complete_cb(nreq, 0, 0);
 257 }
 258
 259 static void
 260 ubus_notify_data_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 261 {
 262         struct ubus_notify_request *nreq;
 263
 264         nreq = container_of(req, struct ubus_notify_request, req);
 265         if (!nreq->data_cb)
 266                 return;
 267
 268         nreq->data_cb(nreq, type, msg);
 269 }
 270
 271 static int
 272 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 273                     const char *type, struct blob_attr *msg,
 274                     struct ubus_notify_request *req, bool reply)
 275 {
 276         memset(req, 0, sizeof(*req));
 277
 278         blob_buf_init(&b, 0);
 279         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 280         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 281
 282         if (!reply)
 283                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 284
 285         if (msg)
 286                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 287
 288         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 289                 return UBUS_STATUS_INVALID_ARGUMENT;
 290
 291         /* wait for status message from ubusd first */
 292         req->req.notify = true;
 293         req->pending = 1;
 294         req->id[0] = obj->id;
 295         req->req.complete_cb = ubus_notify_complete_cb;
 296         req->req.data_cb = ubus_notify_data_cb;
 297
 298         return 0;
 299 }
 300
 301 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 302                       const char *type, struct blob_attr *msg,
 303                       struct ubus_notify_request *req)
 304 {
 305         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 306 }
 307
 308 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 309                 const char *type, struct blob_attr *msg, int timeout)
 310 {
 311         struct ubus_notify_request req;
 312         int ret;
 313
 314         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 315         if (ret < 0)
 316                 return ret;
 317
 318         if (timeout < 0) {
 319                 ubus_abort_request(ctx, &req.req);
 320                 return 0;
 321         }
 322
 323         return ubus_complete_request(ctx, &req.req, timeout);
 324 }
 325
 326 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 327 {
 328         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 329
 330         if (!attrbuf[UBUS_ATTR_STATUS])
 331                 return false;
 332
 333         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 334         return true;
 335 }
 336
 337 static int
 338 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 339 {
 340         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 341
 342         ubus_get_status(buf, &ret);
 343         req->peer = buf->hdr.peer;
 344         ubus_set_req_status(req, ret);
 345
 346         return ret;
 347 }
 348
 349 static void
 350 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 351 {
 352         struct ubus_pending_data *data;
 353         int len;
 354
 355         if (!req->blocked) {
 356                 req->blocked = true;
 357                 req_data_cb(req, buf->hdr.type, buf->data);
 358                 __ubus_process_req_data(req);
 359                 req->blocked = false;
 360
 361                 if (req->status_msg)
 362                         ubus_req_complete_cb(req);
 363
 364                 return;
 365         }
 366
 367         len = blob_raw_len(buf->data);
 368         data = calloc(1, sizeof(*data) + len);
 369         if (!data)
 370                 return;
 371
 372         data->type = buf->hdr.type;
 373         memcpy(data->data, buf->data, len);
 374         list_add(&data->list, &req->pending);
 375 }
 376
 377 static int
 378 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 379 {
 380         uint32_t pending = n->pending;
 381         int i;
 382
 383         for (i = 0; pending; i++, pending >>= 1) {
 384                 if (!(pending & 1))
 385                         continue;
 386
 387                 if (n->id[i] == objid)
 388                         return i;
 389         }
 390
 391         return -1;
 392 }
 393
 394 static struct ubus_request *
 395 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 396 {
 397         struct ubus_request *req;
 398
 399         list_for_each_entry(req, &ctx->requests, list) {
 400                 struct ubus_notify_request *nreq;
 401                 nreq = container_of(req, struct ubus_notify_request, req);
 402
 403                 if (seq != req->seq)
 404                         continue;
 405
 406                 if (req->notify) {
 407                         if (!nreq->pending)
 408                                 continue;
 409
 410                         *id = ubus_find_notify_id(nreq, peer);
 411                         if (*id < 0)
 412                                 continue;
 413                 } else if (peer != req->peer)
 414                         continue;
 415
 416                 return req;
 417         }
 418         return NULL;
 419 }
 420
 421 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 422 {
 423         struct ubus_notify_request *nreq;
 424         struct blob_attr **tb;
 425         struct blob_attr *cur;
 426         int rem, idx = 1;
 427         int ret = 0;
 428
 429         nreq = container_of(req, struct ubus_notify_request, req);
 430         nreq->pending &= ~(1 << id);
 431
 432         if (!id) {
 433                 /* first id: ubusd's status message with a list of ids */
 434                 tb = ubus_parse_msg(buf->data);
 435                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 436                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 437                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 438                                         continue;
 439
 440                                 nreq->pending |= (1 << idx);
 441                                 nreq->id[idx] = blob_get_int32(cur);
 442                                 idx++;
 443
 444                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 445                                         break;
 446                         }
 447                 }
 448         } else {
 449                 ubus_get_status(buf, &ret);
 450                 if (nreq->status_cb)
 451                         nreq->status_cb(nreq, id, ret);
 452         }
 453
 454         if (!nreq->pending)
 455                 ubus_set_req_status(req, 0);
 456 }
 457
 458 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 459 {
 460         struct ubus_msghdr *hdr = &buf->hdr;
 461         struct ubus_request *req;
 462         int id = -1;
 463
 464         switch(hdr->type) {
 465         case UBUS_MSG_STATUS:
 466                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 467                 if (!req)
 468                         break;
 469
 470                 if (fd >= 0) {
 471                         if (req->fd_cb)
 472                                 req->fd_cb(req, fd);
 473                         else
 474                                 close(fd);
 475                 }
 476
 477                 if (id >= 0)
 478                         ubus_process_notify_status(req, id, buf);
 479                 else
 480                         ubus_process_req_status(req, buf);
 481                 break;
 482
 483         case UBUS_MSG_DATA:
 484                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 485                 if (req && (req->data_cb || req->raw_data_cb))
 486                         ubus_process_req_data(req, buf);
 487                 break;
 488         }
 489 }
 490
 491 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 492 {
 493         blob_buf_init(&b, 0);
 494         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 495 }