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 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
  52 {
  53         if (!list_empty(&req->list))
  54                 return;
  55
  56         req->cancelled = true;
  57         __ubus_process_req_data(req);
  58         list_del_init(&req->list);
  59 }
  60
  61 void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
  62 {
  63         if (!list_empty(&req->list))
  64                 return;
  65
  66         list_add(&req->list, &ctx->requests);
  67 }
  68
  69 static void ubus_sync_req_cb(struct ubus_request *req, int ret)
  70 {
  71         req->status_msg = true;
  72         req->status_code = ret;
  73         uloop_end();
  74 }
  75
  76 struct ubus_sync_req_cb {
  77         struct uloop_timeout timeout;
  78         struct ubus_request *req;
  79 };
  80
  81 static void ubus_sync_req_timeout_cb(struct uloop_timeout *timeout)
  82 {
  83         struct ubus_sync_req_cb *cb;
  84
  85         cb = container_of(timeout, struct ubus_sync_req_cb, timeout);
  86         ubus_sync_req_cb(cb->req, UBUS_STATUS_TIMEOUT);
  87 }
  88
  89 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
  90                           int timeout)
  91 {
  92         struct ubus_sync_req_cb cb;
  93         ubus_complete_handler_t complete_cb = req->complete_cb;
  94         bool registered = ctx->sock.registered;
  95         int status = UBUS_STATUS_NO_DATA;
  96
  97         if (!registered) {
  98                 uloop_init();
  99                 ubus_add_uloop(ctx);
 100         }
 101
 102         if (timeout) {
 103                 memset(&cb, 0, sizeof(cb));
 104                 cb.req = req;
 105                 cb.timeout.cb = ubus_sync_req_timeout_cb;
 106                 uloop_timeout_set(&cb.timeout, timeout);
 107         }
 108
 109         ubus_complete_request_async(ctx, req);
 110         req->complete_cb = ubus_sync_req_cb;
 111
 112         ctx->stack_depth++;
 113         while (!req->status_msg) {
 114                 bool cancelled = uloop_cancelled;
 115                 uloop_cancelled = false;
 116                 uloop_run();
 117                 uloop_cancelled = cancelled;
 118         }
 119         ctx->stack_depth--;
 120
 121         if (timeout)
 122                 uloop_timeout_cancel(&cb.timeout);
 123
 124         if (req->status_msg)
 125                 status = req->status_code;
 126
 127         req->complete_cb = complete_cb;
 128         if (req->complete_cb)
 129                 req->complete_cb(req, status);
 130
 131         if (!registered)
 132                 uloop_fd_delete(&ctx->sock);
 133
 134         if (!ctx->stack_depth)
 135                 ubus_process_pending_msg(ctx);
 136
 137         return status;
 138 }
 139
 140 void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
 141 {
 142         blob_buf_init(&b, 0);
 143         blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
 144         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 145         ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer);
 146 }
 147
 148 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 149                     struct blob_attr *msg)
 150 {
 151         int ret;
 152
 153         blob_buf_init(&b, 0);
 154         blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
 155         blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 156         ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer);
 157         if (ret < 0)
 158                 return UBUS_STATUS_NO_DATA;
 159
 160         return 0;
 161 }
 162
 163 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 164                        struct blob_attr *msg, struct ubus_request *req)
 165 {
 166         blob_buf_init(&b, 0);
 167         blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
 168         blob_put_string(&b, UBUS_ATTR_METHOD, method);
 169         if (msg)
 170                 blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
 171
 172         if (ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
 173                 return UBUS_STATUS_INVALID_ARGUMENT;
 174
 175         return 0;
 176 }
 177
 178 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 179                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 180                 int timeout)
 181 {
 182         struct ubus_request req;
 183
 184         ubus_invoke_async(ctx, obj, method, msg, &req);
 185         req.data_cb = cb;
 186         req.priv = priv;
 187         return ubus_complete_request(ctx, &req, timeout);
 188 }
 189
 190 static void ubus_req_complete_cb(struct ubus_request *req)
 191 {
 192         ubus_complete_handler_t cb = req->complete_cb;
 193
 194         if (!cb)
 195                 return;
 196
 197         req->complete_cb = NULL;
 198         cb(req, req->status_code);
 199 }
 200
 201 static bool ubus_get_status(struct ubus_msghdr *hdr, int *ret)
 202 {
 203         struct blob_attr **attrbuf = ubus_parse_msg(hdr->data);
 204
 205         if (!attrbuf[UBUS_ATTR_STATUS])
 206                 return false;
 207
 208         *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
 209         return true;
 210 }
 211
 212 static int
 213 ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr *hdr)
 214 {
 215         int ret = UBUS_STATUS_INVALID_ARGUMENT;
 216
 217         if (!list_empty(&req->list))
 218                 list_del_init(&req->list);
 219
 220         ubus_get_status(hdr, &ret);
 221         req->peer = hdr->peer;
 222         req->status_msg = true;
 223         req->status_code = ret;
 224         if (!req->blocked)
 225                 ubus_req_complete_cb(req);
 226
 227         return ret;
 228 }
 229
 230 static void
 231 ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr *hdr)
 232 {
 233         struct ubus_pending_data *data;
 234         int len;
 235
 236         if (!req->blocked) {
 237                 req->blocked = true;
 238                 req_data_cb(req, hdr->type, hdr->data);
 239                 __ubus_process_req_data(req);
 240                 req->blocked = false;
 241
 242                 if (req->status_msg)
 243                         ubus_req_complete_cb(req);
 244
 245                 return;
 246         }
 247
 248         len = blob_raw_len(hdr->data);
 249         data = calloc(1, sizeof(*data) + len);
 250         if (!data)
 251                 return;
 252
 253         data->type = hdr->type;
 254         memcpy(data->data, hdr->data, len);
 255         list_add(&data->list, &req->pending);
 256 }
 257
 258 static struct ubus_request *
 259 ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer)
 260 {
 261         struct ubus_request *req;
 262
 263         list_for_each_entry(req, &ctx->requests, list) {
 264                 if (seq != req->seq || peer != req->peer)
 265                         continue;
 266
 267                 return req;
 268         }
 269         return NULL;
 270 }
 271
 272 void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
 273 {
 274         struct ubus_request *req;
 275
 276         switch(hdr->type) {
 277         case UBUS_MSG_STATUS:
 278                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 279                 if (!req)
 280                         break;
 281
 282                 ubus_process_req_status(req, hdr);
 283                 break;
 284
 285         case UBUS_MSG_DATA:
 286                 req = ubus_find_request(ctx, hdr->seq, hdr->peer);
 287                 if (req && (req->data_cb || req->raw_data_cb))
 288                         ubus_process_req_data(req, hdr);
 289                 break;
 290         }
 291 }