libubus-req.c

   1 /*
   2  * Copyright (C) 2011-2012 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 "libubus.h"
  15 #include "libubus-internal.h"
  16
  17 struct ubus_pending_data {
  18         struct list_head list;
  19         int type;
  20         struct blob_attr data[];
  21 };
  22
  23 static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
  24 {
  25         struct blob_attr **attr;
  26
  27         if (req->raw_data_cb)
  28                 req->raw_data_cb(req, type, data);
  29
  30         if (!req->data_cb)
  31                 return;
  32
  33         attr = ubus_parse_msg(data);
  34         req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
  35 }
  36
  37 static void __ubus_process_req_data(struct ubus_request *req)
  38 {
  39         struct ubus_pending_data *data;
  40
  41         while (!list_empty(&req->pending)) {
  42                 data = list_first_entry(&req->pending,
  43                         struct ubus_pending_data, list);
  44                 list_del(&data->list);
  45                 if (!req->cancelled)
  46                         req_data_cb(req, data->type, data->data);
  47                 free(data);
  48         }
  49 }
  50
  51 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
  52                                 struct blob_attr *msg, int cmd, uint32_t peer)
  53 {
  54         memset(req, 0, sizeof(*req));
  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         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
  65 }
  66
  67 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
  68 {
  69         if (!list_empty(&req->list))
  70                 return;
  71
  72         req->cancelled = true;
  73         __ubus_process_req_data(req);
  74         list_del_init(&req->list);
  75 }
  76
  77 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
  78 {
  79         if (!list_empty(&req->list))
  80                 return;
  81
  82         list_add(&req->list, &ctx->requests);
  83 }
  84
  85 static void
  86 ubus_req_complete_cb(struct ubus_request *req)
  87 {
  88         ubus_complete_handler_t cb = req->complete_cb;
  89
  90         if (!cb)
  91                 return;
  92
  93         req->complete_cb = NULL;
  94         cb(req, req->status_code);
  95 }
  96
  97 static void
  98 ubus_set_req_status(struct ubus_request *req, int ret)
  99 {
 100         if (!list_empty(&req->list))
 101                 list_del_init(&req->list);
 102
 103         req->status_msg = true;
 104         req->status_code = ret;
 105         if (!req->blocked)
 106                 ubus_req_complete_cb(req);
 107 }
 108
 109 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
 110 {
 111         req->status_msg = true;
 112         req->status_code = ret;
 113         uloop_end();
 114 }
 115
 116 struct ubus_sync_req_cb {
 117         struct uloop_timeout timeout;
 118         struct ubus_request *req;
 119 };
 120
 121 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
 122 {
 123         struct ubus_sync_req_cb *cb;
 124
 125         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 126         ubus_set_req_status(cb->req, UBUS_STATUS_TIMEOUT);
 127 }
 128
 129 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 130                           int timeout)
 131 {
 132         struct ubus_sync_req_cb cb;
 133         ubus_complete_handler_t complete_cb = req->complete_cb;
 134         bool registered = ctx->sock.registered;
 135         int status = UBUS_STATUS_NO_DATA;
 136
 137         if (!registered) {
 138                 uloop_init();
 139                 ubus_add_uloop(ctx);
 140         }
 141
 142         if (timeout) {
 143                 memset(&cb, 0, sizeof(cb));
 144                 cb.req = req;
 145                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 146                 uloop_timeout_set(&cb.timeout, timeout);
 147         }
 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                 uloop_cancelled = false;
 156                 uloop_run();
 157                 uloop_cancelled = cancelled;
 158         }
 159         ctx->stack_depth--;
 160
 161         if (timeout)
 162                 uloop_timeout_cancel(&cb.timeout);
 163
 164         if (req->status_msg)
 165                 status = req->status_code;
 166
 167         req->complete_cb = complete_cb;
 168         if (req->complete_cb)
 169                 req->complete_cb(req, status);
 170
 171         if (!registered)
 172                 uloop_fd_delete(&ctx->sock);
 173
 174         if (!ctx->stack_depth)
 175                 ubus_process_pending_msg(ctx);
 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);
 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);
 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 bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 231 {
 232         struct blob_attr **attrbuf = ubus_parse_msg(hdr->data);
 233
 234         if (!attrbuf[UBUS_ATTR_STATUS])
 235                 return false;
 236
 237         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 238         return true;
 239 }
 240
 241 static int
 242 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 243 {
 244         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 245
 246         ubus_get_status(hdr, &ret);
 247         req->peer = hdr->peer;
 248         ubus_set_req_status(req, ret);
 249
 250         return ret;
 251 }
 252
 253 static void
 254 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 255 {
 256         struct ubus_pending_data *data;
 257         int len;
 258
 259         if (!req->blocked) {
 260                 req->blocked = true;
 261                 req_data_cb(req, hdr->type, hdr->data);
 262                 __ubus_process_req_data(req);
 263                 req->blocked = false;
 264
 265                 if (req->status_msg)
 266                         ubus_req_complete_cb(req);
 267
 268                 return;
 269         }
 270
 271         len = blob_raw_len(hdr->data);
 272         data = calloc(1, sizeof(*data) + len);
 273         if (!data)
 274                 return;
 275
 276         data->type = hdr->type;
 277         memcpy(data->data, hdr->data, len);
 278         list_add(&data->list, &req->pending);
 279 }
 280
 281 static struct ubus_request *
 282 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 283 {
 284         struct ubus_request *req;
 285
 286         list_for_each_entry(req, &ctx->requests, list) {
 287                 if (seq != req->seq || peer != req->peer)
 288                         continue;
 289
 290                 return req;
 291         }
 292         return NULL;
 293 }
 294
 295 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 296 {
 297         struct ubus_request *req;
 298
 299         switch(hdr->type) {
 300         case UBUS_MSG_STATUS:
 301                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 302                 if (!req)
 303                         break;
 304
 305                 ubus_process_req_status(req, hdr);
 306                 break;
 307
 308         case UBUS_MSG_DATA:
 309                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 310                 if (req && (req->data_cb || req->raw_data_cb))
 311                         ubus_process_req_data(req, hdr);
 312                 break;
 313         }
 314 }