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                                 break;
 157                         }
 158                 }
 159                 ubus_poll_data(ctx, (unsigned int) timeout);
 160
 161                 uloop_cancelled = cancelled;
 162         }
 163         ctx->stack_depth--;
 164         if (ctx->stack_depth)
 165                 uloop_cancelled = true;
 166
 167         if (req->status_msg)
 168                 status = req->status_code;
 169
 170         req->complete_cb = complete_cb;
 171         if (req->complete_cb)
 172                 req->complete_cb(req, status);
 173
 174         if (!registered)
 175                 uloop_fd_delete(&ctx->sock);
 176
 177         return status;
 178 }
 179
 180 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 181 {
 182         blob_buf_init(&b, 0);
 183         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 184         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 185         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
 186 }
 187
 188 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 189                     struct blob_attr *msg)
 190 {
 191         int ret;
 192
 193         blob_buf_init(&b, 0);
 194         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 195         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 196         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 197         if (ret < 0)
 198                 return UBUS_STATUS_NO_DATA;
 199
 200         return 0;
 201 }
 202
 203 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 204                        struct blob_attr *msg, struct ubus_request *req)
 205 {
 206         blob_buf_init(&b, 0);
 207         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 208         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 209         if (msg)
 210                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 211
 212         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 213                 return UBUS_STATUS_INVALID_ARGUMENT;
 214
 215         return 0;
 216 }
 217
 218 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 219                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 220                 int timeout)
 221 {
 222         struct ubus_request req;
 223
 224         ubus_invoke_async(ctx, obj, method, msg, &req);
 225         req.data_cb = cb;
 226         req.priv = priv;
 227         return ubus_complete_request(ctx, &req, timeout);
 228 }
 229
 230 static void
 231 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 232 {
 233         struct ubus_notify_request *nreq;
 234
 235         nreq = container_of(req, struct ubus_notify_request, req);
 236         if (!nreq->complete_cb)
 237                 return;
 238
 239         nreq->complete_cb(nreq, 0, 0);
 240 }
 241
 242 static int
 243 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 244                     const char *type, struct blob_attr *msg,
 245                     struct ubus_notify_request *req, bool reply)
 246 {
 247         memset(req, 0, sizeof(*req));
 248
 249         blob_buf_init(&b, 0);
 250         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 251         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 252
 253         if (!reply)
 254                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 255
 256         if (msg)
 257                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 258
 259         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 260                 return UBUS_STATUS_INVALID_ARGUMENT;
 261
 262         /* wait for status message from ubusd first */
 263         req->req.notify = true;
 264         req->pending = 1;
 265         req->id[0] = obj->id;
 266         req->req.complete_cb = ubus_notify_complete_cb;
 267
 268         return 0;
 269 }
 270
 271 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 272                       const char *type, struct blob_attr *msg,
 273                       struct ubus_notify_request *req)
 274 {
 275         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 276 }
 277
 278 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 279                 const char *type, struct blob_attr *msg, int timeout)
 280 {
 281         struct ubus_notify_request req;
 282         int ret;
 283
 284         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 285         if (ret < 0)
 286                 return ret;
 287
 288         if (timeout < 0) {
 289                 ubus_abort_request(ctx, &req.req);
 290                 return 0;
 291         }
 292
 293         return ubus_complete_request(ctx, &req.req, timeout);
 294 }
 295
 296 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 297 {
 298         struct blob_attr **attrbuf = ubus_parse_msg(ubus_msghdr_data(hdr));
 299
 300         if (!attrbuf[UBUS_ATTR_STATUS])
 301                 return false;
 302
 303         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 304         return true;
 305 }
 306
 307 static int
 308 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 309 {
 310         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 311
 312         ubus_get_status(hdr, &ret);
 313         req->peer = hdr->peer;
 314         ubus_set_req_status(req, ret);
 315
 316         return ret;
 317 }
 318
 319 static void
 320 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 321 {
 322         struct blob_attr *msg_data = ubus_msghdr_data(hdr);
 323         struct ubus_pending_data *data;
 324         int len;
 325
 326         if (!req->blocked) {
 327                 req->blocked = true;
 328                 req_data_cb(req, hdr->type, msg_data);
 329                 __ubus_process_req_data(req);
 330                 req->blocked = false;
 331
 332                 if (req->status_msg)
 333                         ubus_req_complete_cb(req);
 334
 335                 return;
 336         }
 337
 338         len = blob_raw_len(msg_data);
 339         data = calloc(1, sizeof(*data) + len);
 340         if (!data)
 341                 return;
 342
 343         data->type = hdr->type;
 344         memcpy(data->data, msg_data, len);
 345         list_add(&data->list, &req->pending);
 346 }
 347
 348 static int
 349 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 350 {
 351         uint32_t pending = n->pending;
 352         int i;
 353
 354         for (i = 0; pending; i++, pending >>= 1) {
 355                 if (!(pending & 1))
 356                         continue;
 357
 358                 if (n->id[i] == objid)
 359                         return i;
 360         }
 361
 362         return -1;
 363 }
 364
 365 static struct ubus_request *
 366 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 367 {
 368         struct ubus_request *req;
 369
 370         list_for_each_entry(req, &ctx->requests, list) {
 371                 struct ubus_notify_request *nreq;
 372                 nreq = container_of(req, struct ubus_notify_request, req);
 373
 374                 if (seq != req->seq)
 375                         continue;
 376
 377                 if (req->notify) {
 378                         if (!nreq->pending)
 379                                 continue;
 380
 381                         *id = ubus_find_notify_id(nreq, peer);
 382                         if (*id < 0)
 383                                 continue;
 384                 } else if (peer != req->peer)
 385                         continue;
 386
 387                 return req;
 388         }
 389         return NULL;
 390 }
 391
 392 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr *hdr)
 393 {
 394         struct ubus_notify_request *nreq;
 395         struct blob_attr **tb;
 396         struct blob_attr *cur;
 397         int rem, idx = 1;
 398         int ret = 0;
 399
 400         nreq = container_of(req, struct ubus_notify_request, req);
 401         nreq->pending &= ~(1 << id);
 402
 403         if (!id) {
 404                 /* first id: ubusd's status message with a list of ids */
 405                 tb = ubus_parse_msg(ubus_msghdr_data(hdr));
 406                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 407                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 408                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 409                                         continue;
 410
 411                                 nreq->pending |= (1 << idx);
 412                                 nreq->id[idx] = blob_get_int32(cur);
 413                                 idx++;
 414
 415                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 416                                         break;
 417                         }
 418                 }
 419         } else {
 420                 ubus_get_status(hdr, &ret);
 421                 if (nreq->status_cb)
 422                         nreq->status_cb(nreq, id, ret);
 423         }
 424
 425         if (!nreq->pending)
 426                 ubus_set_req_status(req, 0);
 427 }
 428
 429 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr, int fd)
 430 {
 431         struct ubus_request *req;
 432         int id = -1;
 433
 434         switch(hdr->type) {
 435         case UBUS_MSG_STATUS:
 436                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 437                 if (!req)
 438                         break;
 439
 440                 if (fd >= 0) {
 441                         if (req->fd_cb)
 442                                 req->fd_cb(req, fd);
 443                         else
 444                                 close(fd);
 445                 }
 446
 447                 if (id >= 0)
 448                         ubus_process_notify_status(req, id, hdr);
 449                 else
 450                         ubus_process_req_status(req, hdr);
 451                 break;
 452
 453         case UBUS_MSG_DATA:
 454                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 455                 if (req && (req->data_cb || req->raw_data_cb))
 456                         ubus_process_req_data(req, hdr);
 457                 break;
 458         }
 459 }