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