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 ubus_sync_req_cb(struct ubus_request *req, int ret)
  86 {
  87         req->status_msg = true;
  88         req->status_code = ret;
  89         uloop_end();
  90 }
  91
  92 struct ubus_sync_req_cb {
  93         struct uloop_timeout timeout;
  94         struct ubus_request *req;
  95 };
  96
  97 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
  98 {
  99         struct ubus_sync_req_cb *cb;
 100
 101         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
 102         ubus_sync_req_cb(cb->req, UBUS_STATUS_TIMEOUT);
 103 }
 104
 105 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 106                           int timeout)
 107 {
 108         struct ubus_sync_req_cb cb;
 109         ubus_complete_handler_t complete_cb = req->complete_cb;
 110         bool registered = ctx->sock.registered;
 111         int status = UBUS_STATUS_NO_DATA;
 112
 113         if (!registered) {
 114                 uloop_init();
 115                 ubus_add_uloop(ctx);
 116         }
 117
 118         if (timeout) {
 119                 memset(&cb, 0, sizeof(cb));
 120                 cb.req = req;
 121                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 122                 uloop_timeout_set(&cb.timeout, timeout);
 123         }
 124
 125         ubus_complete_request_async(ctx, req);
 126         req->complete_cb = ubus_sync_req_cb;
 127
 128         ctx->stack_depth++;
 129         while (!req->status_msg) {
 130                 bool cancelled = uloop_cancelled;
 131                 uloop_cancelled = false;
 132                 uloop_run();
 133                 uloop_cancelled = cancelled;
 134         }
 135         ctx->stack_depth--;
 136
 137         if (timeout)
 138                 uloop_timeout_cancel(&cb.timeout);
 139
 140         if (req->status_msg)
 141                 status = req->status_code;
 142
 143         req->complete_cb = complete_cb;
 144         if (req->complete_cb)
 145                 req->complete_cb(req, status);
 146
 147         if (!registered)
 148                 uloop_fd_delete(&ctx->sock);
 149
 150         if (!ctx->stack_depth)
 151                 ubus_process_pending_msg(ctx);
 152
 153         return status;
 154 }
 155
 156 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 157 {
 158         blob_buf_init(&b, 0);
 159         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 160         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 161         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer);
 162 }
 163
 164 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 165                     struct blob_attr *msg)
 166 {
 167         int ret;
 168
 169         blob_buf_init(&b, 0);
 170         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 171         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 172         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 173         if (ret < 0)
 174                 return UBUS_STATUS_NO_DATA;
 175
 176         return 0;
 177 }
 178
 179 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 180                        struct blob_attr *msg, struct ubus_request *req)
 181 {
 182         blob_buf_init(&b, 0);
 183         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 184         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 185         if (msg)
 186                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 187
 188         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 189                 return UBUS_STATUS_INVALID_ARGUMENT;
 190
 191         return 0;
 192 }
 193
 194 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 195                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 196                 int timeout)
 197 {
 198         struct ubus_request req;
 199
 200         ubus_invoke_async(ctx, obj, method, msg, &req);
 201         req.data_cb = cb;
 202         req.priv = priv;
 203         return ubus_complete_request(ctx, &req, timeout);
 204 }
 205
 206 static void ubus_req_complete_cb(struct ubus_request *req)
 207 {
 208         ubus_complete_handler_t cb = req->complete_cb;
 209
 210         if (!cb)
 211                 return;
 212
 213         req->complete_cb = NULL;
 214         cb(req, req->status_code);
 215 }
 216
 217 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 218 {
 219         struct blob_attr **attrbuf = ubus_parse_msg(hdr->data);
 220
 221         if (!attrbuf[UBUS_ATTR_STATUS])
 222                 return false;
 223
 224         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 225         return true;
 226 }
 227
 228 static int
 229 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 230 {
 231         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 232
 233         if (!list_empty(&req->list))
 234                 list_del_init(&req->list);
 235
 236         ubus_get_status(hdr, &ret);
 237         req->peer = hdr->peer;
 238         req->status_msg = true;
 239         req->status_code = ret;
 240         if (!req->blocked)
 241                 ubus_req_complete_cb(req);
 242
 243         return ret;
 244 }
 245
 246 static void
 247 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 248 {
 249         struct ubus_pending_data *data;
 250         int len;
 251
 252         if (!req->blocked) {
 253                 req->blocked = true;
 254                 req_data_cb(req, hdr->type, hdr->data);
 255                 __ubus_process_req_data(req);
 256                 req->blocked = false;
 257
 258                 if (req->status_msg)
 259                         ubus_req_complete_cb(req);
 260
 261                 return;
 262         }
 263
 264         len = blob_raw_len(hdr->data);
 265         data = calloc(1, sizeof(*data) + len);
 266         if (!data)
 267                 return;
 268
 269         data->type = hdr->type;
 270         memcpy(data->data, hdr->data, len);
 271         list_add(&data->list, &req->pending);
 272 }
 273
 274 static struct ubus_request *
 275 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 276 {
 277         struct ubus_request *req;
 278
 279         list_for_each_entry(req, &ctx->requests, list) {
 280                 if (seq != req->seq || peer != req->peer)
 281                         continue;
 282
 283                 return req;
 284         }
 285         return NULL;
 286 }
 287
 288 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 289 {
 290         struct ubus_request *req;
 291
 292         switch(hdr->type) {
 293         case UBUS_MSG_STATUS:
 294                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 295                 if (!req)
 296                         break;
 297
 298                 ubus_process_req_status(req, hdr);
 299                 break;
 300
 301         case UBUS_MSG_DATA:
 302                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 303                 if (req && (req->data_cb || req->raw_data_cb))
 304                         ubus_process_req_data(req, hdr);
 305                 break;
 306         }
 307 }