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