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                 if (ctx->sock.eof) {
 164                         ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
 165                         break;
 166                 }
 167         }
 168         ctx->stack_depth--;
 169         if (ctx->stack_depth)
 170                 uloop_cancelled = true;
 171
 172         if (req->status_msg)
 173                 status = req->status_code;
 174
 175         req->complete_cb = complete_cb;
 176         if (req->complete_cb)
 177                 req->complete_cb(req, status);
 178
 179         if (!registered) {
 180                 uloop_fd_delete(&ctx->sock);
 181
 182                 if (!ctx->stack_depth)
 183                         ctx->pending_timer.cb(&ctx->pending_timer);
 184         }
 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 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 198                     struct blob_attr *msg)
 199 {
 200         int ret;
 201
 202         blob_buf_init(&b, 0);
 203         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 204         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 205         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 206         if (ret < 0)
 207                 return UBUS_STATUS_NO_DATA;
 208
 209         return 0;
 210 }
 211
 212 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 213                        struct blob_attr *msg, struct ubus_request *req)
 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         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 222                 return UBUS_STATUS_INVALID_ARGUMENT;
 223
 224         return 0;
 225 }
 226
 227 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 228                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 229                 int timeout)
 230 {
 231         struct ubus_request req;
 232         int rc;
 233
 234         rc = ubus_invoke_async(ctx, obj, method, msg, &req);
 235         if (rc)
 236                 return rc;
 237
 238         req.data_cb = cb;
 239         req.priv = priv;
 240         return ubus_complete_request(ctx, &req, timeout);
 241 }
 242
 243 static void
 244 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 245 {
 246         struct ubus_notify_request *nreq;
 247
 248         nreq = container_of(req, struct ubus_notify_request, req);
 249         if (!nreq->complete_cb)
 250                 return;
 251
 252         nreq->complete_cb(nreq, 0, 0);
 253 }
 254
 255 static int
 256 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 257                     const char *type, struct blob_attr *msg,
 258                     struct ubus_notify_request *req, bool reply)
 259 {
 260         memset(req, 0, sizeof(*req));
 261
 262         blob_buf_init(&b, 0);
 263         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 264         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 265
 266         if (!reply)
 267                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 268
 269         if (msg)
 270                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 271
 272         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 273                 return UBUS_STATUS_INVALID_ARGUMENT;
 274
 275         /* wait for status message from ubusd first */
 276         req->req.notify = true;
 277         req->pending = 1;
 278         req->id[0] = obj->id;
 279         req->req.complete_cb = ubus_notify_complete_cb;
 280
 281         return 0;
 282 }
 283
 284 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 285                       const char *type, struct blob_attr *msg,
 286                       struct ubus_notify_request *req)
 287 {
 288         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 289 }
 290
 291 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 292                 const char *type, struct blob_attr *msg, int timeout)
 293 {
 294         struct ubus_notify_request req;
 295         int ret;
 296
 297         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 298         if (ret < 0)
 299                 return ret;
 300
 301         if (timeout < 0) {
 302                 ubus_abort_request(ctx, &req.req);
 303                 return 0;
 304         }
 305
 306         return ubus_complete_request(ctx, &req.req, timeout);
 307 }
 308
 309 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 310 {
 311         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 312
 313         if (!attrbuf[UBUS_ATTR_STATUS])
 314                 return false;
 315
 316         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 317         return true;
 318 }
 319
 320 static int
 321 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 322 {
 323         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 324
 325         ubus_get_status(buf, &ret);
 326         req->peer = buf->hdr.peer;
 327         ubus_set_req_status(req, ret);
 328
 329         return ret;
 330 }
 331
 332 static void
 333 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 334 {
 335         struct ubus_pending_data *data;
 336         int len;
 337
 338         if (!req->blocked) {
 339                 req->blocked = true;
 340                 req_data_cb(req, buf->hdr.type, buf->data);
 341                 __ubus_process_req_data(req);
 342                 req->blocked = false;
 343
 344                 if (req->status_msg)
 345                         ubus_req_complete_cb(req);
 346
 347                 return;
 348         }
 349
 350         len = blob_raw_len(buf->data);
 351         data = calloc(1, sizeof(*data) + len);
 352         if (!data)
 353                 return;
 354
 355         data->type = buf->hdr.type;
 356         memcpy(data->data, buf->data, len);
 357         list_add(&data->list, &req->pending);
 358 }
 359
 360 static int
 361 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 362 {
 363         uint32_t pending = n->pending;
 364         int i;
 365
 366         for (i = 0; pending; i++, pending >>= 1) {
 367                 if (!(pending & 1))
 368                         continue;
 369
 370                 if (n->id[i] == objid)
 371                         return i;
 372         }
 373
 374         return -1;
 375 }
 376
 377 static struct ubus_request *
 378 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 379 {
 380         struct ubus_request *req;
 381
 382         list_for_each_entry(req, &ctx->requests, list) {
 383                 struct ubus_notify_request *nreq;
 384                 nreq = container_of(req, struct ubus_notify_request, req);
 385
 386                 if (seq != req->seq)
 387                         continue;
 388
 389                 if (req->notify) {
 390                         if (!nreq->pending)
 391                                 continue;
 392
 393                         *id = ubus_find_notify_id(nreq, peer);
 394                         if (*id < 0)
 395                                 continue;
 396                 } else if (peer != req->peer)
 397                         continue;
 398
 399                 return req;
 400         }
 401         return NULL;
 402 }
 403
 404 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 405 {
 406         struct ubus_notify_request *nreq;
 407         struct blob_attr **tb;
 408         struct blob_attr *cur;
 409         int rem, idx = 1;
 410         int ret = 0;
 411
 412         nreq = container_of(req, struct ubus_notify_request, req);
 413         nreq->pending &= ~(1 << id);
 414
 415         if (!id) {
 416                 /* first id: ubusd's status message with a list of ids */
 417                 tb = ubus_parse_msg(buf->data);
 418                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 419                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 420                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 421                                         continue;
 422
 423                                 nreq->pending |= (1 << idx);
 424                                 nreq->id[idx] = blob_get_int32(cur);
 425                                 idx++;
 426
 427                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 428                                         break;
 429                         }
 430                 }
 431         } else {
 432                 ubus_get_status(buf, &ret);
 433                 if (nreq->status_cb)
 434                         nreq->status_cb(nreq, id, ret);
 435         }
 436
 437         if (!nreq->pending)
 438                 ubus_set_req_status(req, 0);
 439 }
 440
 441 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 442 {
 443         struct ubus_msghdr *hdr = &buf->hdr;
 444         struct ubus_request *req;
 445         int id = -1;
 446
 447         switch(hdr->type) {
 448         case UBUS_MSG_STATUS:
 449                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 450                 if (!req)
 451                         break;
 452
 453                 if (fd >= 0) {
 454                         if (req->fd_cb)
 455                                 req->fd_cb(req, fd);
 456                         else
 457                                 close(fd);
 458                 }
 459
 460                 if (id >= 0)
 461                         ubus_process_notify_status(req, id, buf);
 462                 else
 463                         ubus_process_req_status(req, buf);
 464                 break;
 465
 466         case UBUS_MSG_DATA:
 467                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 468                 if (req && (req->data_cb || req->raw_data_cb))
 469                         ubus_process_req_data(req, buf);
 470                 break;
 471         }
 472 }
 473
 474 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 475 {
 476         blob_buf_init(&b, 0);
 477         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 478 }