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         uloop_end();
 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                 bool cancelled = uloop_cancelled;
 155
 156                 uloop_cancelled = false;
 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                                 uloop_cancelled = cancelled;
 162                                 break;
 163                         }
 164                 }
 165                 ubus_poll_data(ctx, (unsigned int) timeout);
 166
 167                 uloop_cancelled = cancelled;
 168                 if (ctx->sock.eof) {
 169                         ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
 170                         break;
 171                 }
 172         }
 173         ctx->stack_depth--;
 174         if (ctx->stack_depth)
 175                 uloop_cancelled = true;
 176
 177         if (req->status_msg)
 178                 status = req->status_code;
 179
 180         req->complete_cb = complete_cb;
 181         if (req->complete_cb)
 182                 req->complete_cb(req, status);
 183
 184         if (!ctx->stack_depth && !ctx->sock.registered)
 185                 ctx->pending_timer.cb(&ctx->pending_timer);
 186
 187         return status;
 188 }
 189
 190 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 191 {
 192         blob_buf_init(&b, 0);
 193         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 194         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 195         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
 196 }
 197
 198 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 199                     struct blob_attr *msg)
 200 {
 201         int ret;
 202
 203         blob_buf_init(&b, 0);
 204         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 205         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 206         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
 207         if (ret < 0)
 208                 return UBUS_STATUS_NO_DATA;
 209
 210         return 0;
 211 }
 212
 213 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj,
 214                          const char *method, struct blob_attr *msg,
 215                          struct ubus_request *req, int fd)
 216 {
 217         blob_buf_init(&b, 0);
 218         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 219         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 220         if (msg)
 221                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 222
 223         memset(req, 0, sizeof(*req));
 224         req->fd = fd;
 225         if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 226                 return UBUS_STATUS_INVALID_ARGUMENT;
 227         return 0;
 228 }
 229
 230 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 231                    struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 232                    int timeout, int fd)
 233 {
 234         struct ubus_request req;
 235         int rc;
 236
 237         rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
 238         if (rc)
 239                 return rc;
 240
 241         req.data_cb = cb;
 242         req.priv = priv;
 243         return ubus_complete_request(ctx, &req, timeout);
 244 }
 245
 246 static void
 247 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 248 {
 249         struct ubus_notify_request *nreq;
 250
 251         nreq = container_of(req, struct ubus_notify_request, req);
 252         if (!nreq->complete_cb)
 253                 return;
 254
 255         nreq->complete_cb(nreq, 0, 0);
 256 }
 257
 258 static int
 259 __ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 260                     const char *type, struct blob_attr *msg,
 261                     struct ubus_notify_request *req, bool reply)
 262 {
 263         memset(req, 0, sizeof(*req));
 264
 265         blob_buf_init(&b, 0);
 266         blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
 267         blob_put_string(&b, UBUS_ATTR_METHOD, type);
 268
 269         if (!reply)
 270                 blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 271
 272         if (msg)
 273                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 274
 275         if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
 276                 return UBUS_STATUS_INVALID_ARGUMENT;
 277
 278         /* wait for status message from ubusd first */
 279         req->req.notify = true;
 280         req->pending = 1;
 281         req->id[0] = obj->id;
 282         req->req.complete_cb = ubus_notify_complete_cb;
 283
 284         return 0;
 285 }
 286
 287 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 288                       const char *type, struct blob_attr *msg,
 289                       struct ubus_notify_request *req)
 290 {
 291         return __ubus_notify_async(ctx, obj, type, msg, req, true);
 292 }
 293
 294 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 295                 const char *type, struct blob_attr *msg, int timeout)
 296 {
 297         struct ubus_notify_request req;
 298         int ret;
 299
 300         ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
 301         if (ret < 0)
 302                 return ret;
 303
 304         if (timeout < 0) {
 305                 ubus_abort_request(ctx, &req.req);
 306                 return 0;
 307         }
 308
 309         return ubus_complete_request(ctx, &req.req, timeout);
 310 }
 311
 312 static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
 313 {
 314         struct blob_attr **attrbuf = ubus_parse_msg(buf->data);
 315
 316         if (!attrbuf[UBUS_ATTR_STATUS])
 317                 return false;
 318
 319         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 320         return true;
 321 }
 322
 323 static int
 324 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 325 {
 326         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 327
 328         ubus_get_status(buf, &ret);
 329         req->peer = buf->hdr.peer;
 330         ubus_set_req_status(req, ret);
 331
 332         return ret;
 333 }
 334
 335 static void
 336 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
 337 {
 338         struct ubus_pending_data *data;
 339         int len;
 340
 341         if (!req->blocked) {
 342                 req->blocked = true;
 343                 req_data_cb(req, buf->hdr.type, buf->data);
 344                 __ubus_process_req_data(req);
 345                 req->blocked = false;
 346
 347                 if (req->status_msg)
 348                         ubus_req_complete_cb(req);
 349
 350                 return;
 351         }
 352
 353         len = blob_raw_len(buf->data);
 354         data = calloc(1, sizeof(*data) + len);
 355         if (!data)
 356                 return;
 357
 358         data->type = buf->hdr.type;
 359         memcpy(data->data, buf->data, len);
 360         list_add(&data->list, &req->pending);
 361 }
 362
 363 static int
 364 ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
 365 {
 366         uint32_t pending = n->pending;
 367         int i;
 368
 369         for (i = 0; pending; i++, pending >>= 1) {
 370                 if (!(pending & 1))
 371                         continue;
 372
 373                 if (n->id[i] == objid)
 374                         return i;
 375         }
 376
 377         return -1;
 378 }
 379
 380 static struct ubus_request *
 381 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
 382 {
 383         struct ubus_request *req;
 384
 385         list_for_each_entry(req, &ctx->requests, list) {
 386                 struct ubus_notify_request *nreq;
 387                 nreq = container_of(req, struct ubus_notify_request, req);
 388
 389                 if (seq != req->seq)
 390                         continue;
 391
 392                 if (req->notify) {
 393                         if (!nreq->pending)
 394                                 continue;
 395
 396                         *id = ubus_find_notify_id(nreq, peer);
 397                         if (*id < 0)
 398                                 continue;
 399                 } else if (peer != req->peer)
 400                         continue;
 401
 402                 return req;
 403         }
 404         return NULL;
 405 }
 406
 407 static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
 408 {
 409         struct ubus_notify_request *nreq;
 410         struct blob_attr **tb;
 411         struct blob_attr *cur;
 412         int rem, idx = 1;
 413         int ret = 0;
 414
 415         nreq = container_of(req, struct ubus_notify_request, req);
 416         nreq->pending &= ~(1 << id);
 417
 418         if (!id) {
 419                 /* first id: ubusd's status message with a list of ids */
 420                 tb = ubus_parse_msg(buf->data);
 421                 if (tb[UBUS_ATTR_SUBSCRIBERS]) {
 422                         blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
 423                                 if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
 424                                         continue;
 425
 426                                 nreq->pending |= (1 << idx);
 427                                 nreq->id[idx] = blob_get_int32(cur);
 428                                 idx++;
 429
 430                                 if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
 431                                         break;
 432                         }
 433                 }
 434         } else {
 435                 ubus_get_status(buf, &ret);
 436                 if (nreq->status_cb)
 437                         nreq->status_cb(nreq, id, ret);
 438         }
 439
 440         if (!nreq->pending)
 441                 ubus_set_req_status(req, 0);
 442 }
 443
 444 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 445 {
 446         struct ubus_msghdr *hdr = &buf->hdr;
 447         struct ubus_request *req;
 448         int id = -1;
 449
 450         switch(hdr->type) {
 451         case UBUS_MSG_STATUS:
 452                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 453                 if (!req)
 454                         break;
 455
 456                 if (fd >= 0) {
 457                         if (req->fd_cb)
 458                                 req->fd_cb(req, fd);
 459                         else
 460                                 close(fd);
 461                 }
 462
 463                 if (id >= 0)
 464                         ubus_process_notify_status(req, id, buf);
 465                 else
 466                         ubus_process_req_status(req, buf);
 467                 break;
 468
 469         case UBUS_MSG_DATA:
 470                 req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
 471                 if (req && (req->data_cb || req->raw_data_cb))
 472                         ubus_process_req_data(req, buf);
 473                 break;
 474         }
 475 }
 476
 477 int __ubus_monitor(struct ubus_context *ctx, const char *type)
 478 {
 479         blob_buf_init(&b, 0);
 480         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
 481 }