libubus.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 <sys/types.h>
  15 #include <sys/socket.h>
  16 #include <unistd.h>
  17
  18 #include <libubox/blob.h>
  19 #include <libubox/blobmsg.h>
  20
  21 #include "libubus.h"
  22 #include "libubus-internal.h"
  23 #include "ubusmsg.h"
  24
  25 const char *__ubus_strerror[__UBUS_STATUS_LAST] = {
  26         [UBUS_STATUS_OK] = "Success",
  27         [UBUS_STATUS_INVALID_COMMAND] = "Invalid command",
  28         [UBUS_STATUS_INVALID_ARGUMENT] = "Invalid argument",
  29         [UBUS_STATUS_METHOD_NOT_FOUND] = "Method not found",
  30         [UBUS_STATUS_NOT_FOUND] = "Not found",
  31         [UBUS_STATUS_NO_DATA] = "No response",
  32         [UBUS_STATUS_PERMISSION_DENIED] = "Permission denied",
  33         [UBUS_STATUS_TIMEOUT] = "Request timed out",
  34         [UBUS_STATUS_NOT_SUPPORTED] = "Operation not supported",
  35         [UBUS_STATUS_UNKNOWN_ERROR] = "Unknown error",
  36         [UBUS_STATUS_CONNECTION_FAILED] = "Connection failed",
  37 };
  38
  39 struct blob_buf b __hidden = {};
  40
  41 struct ubus_pending_msg {
  42         struct list_head list;
  43         struct ubus_msghdr_buf hdr;
  44 };
  45
  46 static int ubus_cmp_id(const void *k1, const void *k2, void *ptr)
  47 {
  48         const uint32_t *id1 = k1, *id2 = k2;
  49
  50         if (*id1 < *id2)
  51                 return -1;
  52         else
  53                 return *id1 > *id2;
  54 }
  55
  56 const char *ubus_strerror(int error)
  57 {
  58         static char err[32];
  59
  60         if (error < 0 || error >= __UBUS_STATUS_LAST)
  61                 goto out;
  62
  63         if (!__ubus_strerror[error])
  64                 goto out;
  65
  66         return __ubus_strerror[error];
  67
  68 out:
  69         sprintf(err, "Unknown error: %d", error);
  70         return err;
  71 }
  72
  73 static void
  74 ubus_queue_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf)
  75 {
  76         struct ubus_pending_msg *pending;
  77         void *data;
  78
  79         pending = calloc_a(sizeof(*pending), &data, blob_raw_len(buf->data));
  80
  81         pending->hdr.data = data;
  82         memcpy(&pending->hdr.hdr, &buf->hdr, sizeof(buf->hdr));
  83         memcpy(data, buf->data, blob_raw_len(buf->data));
  84         list_add_tail(&pending->list, &ctx->pending);
  85         if (ctx->sock.registered)
  86                 uloop_timeout_set(&ctx->pending_timer, 1);
  87 }
  88
  89 void __hidden
  90 ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
  91 {
  92         switch(buf->hdr.type) {
  93         case UBUS_MSG_STATUS:
  94         case UBUS_MSG_DATA:
  95                 ubus_process_req_msg(ctx, buf, fd);
  96                 break;
  97
  98         case UBUS_MSG_INVOKE:
  99         case UBUS_MSG_UNSUBSCRIBE:
 100         case UBUS_MSG_NOTIFY:
 101                 if (ctx->stack_depth) {
 102                         ubus_queue_msg(ctx, buf);
 103                         break;
 104                 }
 105
 106                 ubus_process_obj_msg(ctx, buf, fd);
 107                 break;
 108         case UBUS_MSG_MONITOR:
 109                 if (ctx->monitor_cb)
 110                         ctx->monitor_cb(ctx, buf->hdr.seq, buf->data);
 111                 break;
 112         }
 113 }
 114
 115 static void ubus_process_pending_msg(struct uloop_timeout *timeout)
 116 {
 117         struct ubus_context *ctx = container_of(timeout, struct ubus_context, pending_timer);
 118         struct ubus_pending_msg *pending;
 119
 120         while (!list_empty(&ctx->pending)) {
 121                 if (ctx->stack_depth)
 122                         break;
 123
 124                 pending = list_first_entry(&ctx->pending, struct ubus_pending_msg, list);
 125                 list_del(&pending->list);
 126                 ubus_process_msg(ctx, &pending->hdr, -1);
 127                 free(pending);
 128         }
 129 }
 130
 131 struct ubus_lookup_request {
 132         struct ubus_request req;
 133         ubus_lookup_handler_t cb;
 134 };
 135
 136 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 137 {
 138         struct ubus_lookup_request *req;
 139         struct ubus_object_data obj = {};
 140         struct blob_attr **attr;
 141
 142         req = container_of(ureq, struct ubus_lookup_request, req);
 143         attr = ubus_parse_msg(msg, blob_raw_len(msg));
 144
 145         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 146             !attr[UBUS_ATTR_OBJTYPE])
 147                 return;
 148
 149         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 150         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 151         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 152         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 153         req->cb(ureq->ctx, &obj, ureq->priv);
 154 }
 155
 156 int ubus_lookup(struct ubus_context *ctx, const char *path,
 157                 ubus_lookup_handler_t cb, void *priv)
 158 {
 159         struct ubus_lookup_request lookup;
 160
 161         blob_buf_init(&b, 0);
 162         if (path)
 163                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 164
 165         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 166                 return UBUS_STATUS_INVALID_ARGUMENT;
 167
 168         lookup.req.raw_data_cb = ubus_lookup_cb;
 169         lookup.req.priv = priv;
 170         lookup.cb = cb;
 171         return ubus_complete_request(ctx, &lookup.req, 0);
 172 }
 173
 174 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 175 {
 176         struct blob_attr **attr;
 177         uint32_t *id = req->priv;
 178
 179         attr = ubus_parse_msg(msg, blob_raw_len(msg));
 180
 181         if (!attr[UBUS_ATTR_OBJID])
 182                 return;
 183
 184         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 185 }
 186
 187 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 188 {
 189         struct ubus_request req;
 190
 191         blob_buf_init(&b, 0);
 192         if (path)
 193                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 194
 195         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 196                 return UBUS_STATUS_INVALID_ARGUMENT;
 197
 198         req.raw_data_cb = ubus_lookup_id_cb;
 199         req.priv = id;
 200
 201         return ubus_complete_request(ctx, &req, 0);
 202 }
 203
 204 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 205                          struct ubus_request_data *req,
 206                          const char *method, struct blob_attr *msg)
 207 {
 208         struct ubus_event_handler *ev;
 209
 210         ev = container_of(obj, struct ubus_event_handler, obj);
 211         ev->cb(ctx, ev, method, msg);
 212         return 0;
 213 }
 214
 215 static const struct ubus_method event_method = {
 216         .name = NULL,
 217         .handler = ubus_event_cb,
 218 };
 219
 220 int ubus_register_event_handler(struct ubus_context *ctx,
 221                                 struct ubus_event_handler *ev,
 222                                 const char *pattern)
 223 {
 224         struct ubus_object *obj = &ev->obj;
 225         struct blob_buf b2 = {};
 226         int ret;
 227
 228         if (!obj->id) {
 229                 obj->methods = &event_method;
 230                 obj->n_methods = 1;
 231
 232                 if (!!obj->name ^ !!obj->type)
 233                         return UBUS_STATUS_INVALID_ARGUMENT;
 234
 235                 ret = ubus_add_object(ctx, obj);
 236                 if (ret)
 237                         return ret;
 238         }
 239
 240         /* use a second buffer, ubus_invoke() overwrites the primary one */
 241         blob_buf_init(&b2, 0);
 242         blobmsg_add_u32(&b2, "object", obj->id);
 243         if (pattern)
 244                 blobmsg_add_string(&b2, "pattern", pattern);
 245
 246         ret = ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 247                           NULL, NULL, 0);
 248         blob_buf_free(&b2);
 249
 250         return ret;
 251 }
 252
 253 int ubus_send_event(struct ubus_context *ctx, const char *id,
 254                     struct blob_attr *data)
 255 {
 256         struct ubus_request req;
 257         void *s;
 258
 259         blob_buf_init(&b, 0);
 260         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 261         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 262         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 263         blobmsg_add_string(&b, "id", id);
 264         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 265         blob_nest_end(&b, s);
 266
 267         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 268                 return UBUS_STATUS_INVALID_ARGUMENT;
 269
 270         return ubus_complete_request(ctx, &req, 0);
 271 }
 272
 273 static void ubus_default_connection_lost(struct ubus_context *ctx)
 274 {
 275         if (ctx->sock.registered)
 276                 uloop_end();
 277 }
 278
 279 int ubus_connect_ctx(struct ubus_context *ctx, const char *path)
 280 {
 281         uloop_init();
 282         memset(ctx, 0, sizeof(*ctx));
 283
 284         ctx->sock.fd = -1;
 285         ctx->sock.cb = ubus_handle_data;
 286         ctx->connection_lost = ubus_default_connection_lost;
 287         ctx->pending_timer.cb = ubus_process_pending_msg;
 288
 289         ctx->msgbuf.data = calloc(1, UBUS_MSG_CHUNK_SIZE);
 290         if (!ctx->msgbuf.data)
 291                 return -1;
 292         ctx->msgbuf_data_len = UBUS_MSG_CHUNK_SIZE;
 293
 294         INIT_LIST_HEAD(&ctx->requests);
 295         INIT_LIST_HEAD(&ctx->pending);
 296         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 297         if (ubus_reconnect(ctx, path)) {
 298                 free(ctx->msgbuf.data);
 299                 ctx->msgbuf.data = NULL;
 300                 return -1;
 301         }
 302
 303         return 0;
 304 }
 305
 306 static void ubus_auto_reconnect_cb(struct uloop_timeout *timeout)
 307 {
 308         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 309
 310         if (!ubus_reconnect(&conn->ctx, conn->path))
 311                 ubus_add_uloop(&conn->ctx);
 312         else
 313                 uloop_timeout_set(timeout, 1000);
 314 }
 315
 316 static void ubus_auto_disconnect_cb(struct ubus_context *ctx)
 317 {
 318         struct ubus_auto_conn *conn = container_of(ctx, struct ubus_auto_conn, ctx);
 319
 320         conn->timer.cb = ubus_auto_reconnect_cb;
 321         uloop_timeout_set(&conn->timer, 1000);
 322 }
 323
 324 static void ubus_auto_connect_cb(struct uloop_timeout *timeout)
 325 {
 326         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 327
 328         if (ubus_connect_ctx(&conn->ctx, conn->path)) {
 329                 uloop_timeout_set(timeout, 1000);
 330                 fprintf(stderr, "failed to connect to ubus\n");
 331                 return;
 332         }
 333         conn->ctx.connection_lost = ubus_auto_disconnect_cb;
 334         if (conn->cb)
 335                 conn->cb(&conn->ctx);
 336         ubus_add_uloop(&conn->ctx);
 337 }
 338
 339 void ubus_auto_connect(struct ubus_auto_conn *conn)
 340 {
 341         conn->timer.cb = ubus_auto_connect_cb;
 342         ubus_auto_connect_cb(&conn->timer);
 343 }
 344
 345 struct ubus_context *ubus_connect(const char *path)
 346 {
 347         struct ubus_context *ctx;
 348
 349         ctx = calloc(1, sizeof(*ctx));
 350         if (!ctx)
 351                 return NULL;
 352
 353         if (ubus_connect_ctx(ctx, path)) {
 354                 free(ctx);
 355                 ctx = NULL;
 356         }
 357
 358         return ctx;
 359 }
 360
 361 void ubus_shutdown(struct ubus_context *ctx)
 362 {
 363         blob_buf_free(&b);
 364         if (!ctx)
 365                 return;
 366         close(ctx->sock.fd);
 367         uloop_timeout_cancel(&ctx->pending_timer);
 368         free(ctx->msgbuf.data);
 369 }
 370
 371 void ubus_free(struct ubus_context *ctx)
 372 {
 373         ubus_shutdown(ctx);
 374         free(ctx);
 375 }