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                 ctx->stack_depth++;
 107                 ubus_process_obj_msg(ctx, buf, fd);
 108                 ctx->stack_depth--;
 109                 break;
 110         case UBUS_MSG_MONITOR:
 111                 if (ctx->monitor_cb)
 112                         ctx->monitor_cb(ctx, buf->hdr.seq, buf->data);
 113                 break;
 114         }
 115 }
 116
 117 static void ubus_process_pending_msg(struct uloop_timeout *timeout)
 118 {
 119         struct ubus_context *ctx = container_of(timeout, struct ubus_context, pending_timer);
 120         struct ubus_pending_msg *pending;
 121
 122         while (!list_empty(&ctx->pending)) {
 123                 if (ctx->stack_depth)
 124                         break;
 125
 126                 pending = list_first_entry(&ctx->pending, struct ubus_pending_msg, list);
 127                 list_del(&pending->list);
 128                 ubus_process_msg(ctx, &pending->hdr, -1);
 129                 free(pending);
 130         }
 131 }
 132
 133 struct ubus_lookup_request {
 134         struct ubus_request req;
 135         ubus_lookup_handler_t cb;
 136 };
 137
 138 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 139 {
 140         struct ubus_lookup_request *req;
 141         struct ubus_object_data obj = {};
 142         struct blob_attr **attr;
 143
 144         req = container_of(ureq, struct ubus_lookup_request, req);
 145         attr = ubus_parse_msg(msg, blob_raw_len(msg));
 146
 147         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 148             !attr[UBUS_ATTR_OBJTYPE])
 149                 return;
 150
 151         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 152         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 153         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 154         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 155         req->cb(ureq->ctx, &obj, ureq->priv);
 156 }
 157
 158 int ubus_lookup(struct ubus_context *ctx, const char *path,
 159                 ubus_lookup_handler_t cb, void *priv)
 160 {
 161         struct ubus_lookup_request lookup;
 162
 163         blob_buf_init(&b, 0);
 164         if (path)
 165                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 166
 167         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 168                 return UBUS_STATUS_INVALID_ARGUMENT;
 169
 170         lookup.req.raw_data_cb = ubus_lookup_cb;
 171         lookup.req.priv = priv;
 172         lookup.cb = cb;
 173         return ubus_complete_request(ctx, &lookup.req, 0);
 174 }
 175
 176 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 177 {
 178         struct blob_attr **attr;
 179         uint32_t *id = req->priv;
 180
 181         attr = ubus_parse_msg(msg, blob_raw_len(msg));
 182
 183         if (!attr[UBUS_ATTR_OBJID])
 184                 return;
 185
 186         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 187 }
 188
 189 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 190 {
 191         struct ubus_request req;
 192
 193         blob_buf_init(&b, 0);
 194         if (path)
 195                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 196
 197         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 198                 return UBUS_STATUS_INVALID_ARGUMENT;
 199
 200         req.raw_data_cb = ubus_lookup_id_cb;
 201         req.priv = id;
 202
 203         return ubus_complete_request(ctx, &req, 0);
 204 }
 205
 206 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 207                          struct ubus_request_data *req,
 208                          const char *method, struct blob_attr *msg)
 209 {
 210         struct ubus_event_handler *ev;
 211
 212         ev = container_of(obj, struct ubus_event_handler, obj);
 213         ev->cb(ctx, ev, method, msg);
 214         return 0;
 215 }
 216
 217 static const struct ubus_method event_method = {
 218         .name = NULL,
 219         .handler = ubus_event_cb,
 220 };
 221
 222 int ubus_register_event_handler(struct ubus_context *ctx,
 223                                 struct ubus_event_handler *ev,
 224                                 const char *pattern)
 225 {
 226         struct ubus_object *obj = &ev->obj;
 227         struct blob_buf b2 = {};
 228         int ret;
 229
 230         if (!obj->id) {
 231                 obj->methods = &event_method;
 232                 obj->n_methods = 1;
 233
 234                 if (!!obj->name ^ !!obj->type)
 235                         return UBUS_STATUS_INVALID_ARGUMENT;
 236
 237                 ret = ubus_add_object(ctx, obj);
 238                 if (ret)
 239                         return ret;
 240         }
 241
 242         /* use a second buffer, ubus_invoke() overwrites the primary one */
 243         blob_buf_init(&b2, 0);
 244         blobmsg_add_u32(&b2, "object", obj->id);
 245         if (pattern)
 246                 blobmsg_add_string(&b2, "pattern", pattern);
 247
 248         ret = ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 249                           NULL, NULL, 0);
 250         blob_buf_free(&b2);
 251
 252         return ret;
 253 }
 254
 255 int ubus_send_event(struct ubus_context *ctx, const char *id,
 256                     struct blob_attr *data)
 257 {
 258         struct ubus_request req;
 259         void *s;
 260
 261         blob_buf_init(&b, 0);
 262         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 263         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 264         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 265         blobmsg_add_string(&b, "id", id);
 266         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 267         blob_nest_end(&b, s);
 268
 269         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 270                 return UBUS_STATUS_INVALID_ARGUMENT;
 271
 272         return ubus_complete_request(ctx, &req, 0);
 273 }
 274
 275 static void ubus_default_connection_lost(struct ubus_context *ctx)
 276 {
 277         if (ctx->sock.registered)
 278                 uloop_end();
 279 }
 280
 281 int ubus_connect_ctx(struct ubus_context *ctx, const char *path)
 282 {
 283         uloop_init();
 284         memset(ctx, 0, sizeof(*ctx));
 285
 286         ctx->sock.fd = -1;
 287         ctx->sock.cb = ubus_handle_data;
 288         ctx->connection_lost = ubus_default_connection_lost;
 289         ctx->pending_timer.cb = ubus_process_pending_msg;
 290
 291         ctx->msgbuf.data = calloc(1, UBUS_MSG_CHUNK_SIZE);
 292         if (!ctx->msgbuf.data)
 293                 return -1;
 294         ctx->msgbuf_data_len = UBUS_MSG_CHUNK_SIZE;
 295
 296         INIT_LIST_HEAD(&ctx->requests);
 297         INIT_LIST_HEAD(&ctx->pending);
 298         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 299         if (ubus_reconnect(ctx, path)) {
 300                 free(ctx->msgbuf.data);
 301                 ctx->msgbuf.data = NULL;
 302                 return -1;
 303         }
 304
 305         return 0;
 306 }
 307
 308 static void ubus_auto_reconnect_cb(struct uloop_timeout *timeout)
 309 {
 310         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 311
 312         if (!ubus_reconnect(&conn->ctx, conn->path))
 313                 ubus_add_uloop(&conn->ctx);
 314         else
 315                 uloop_timeout_set(timeout, 1000);
 316 }
 317
 318 static void ubus_auto_disconnect_cb(struct ubus_context *ctx)
 319 {
 320         struct ubus_auto_conn *conn = container_of(ctx, struct ubus_auto_conn, ctx);
 321
 322         conn->timer.cb = ubus_auto_reconnect_cb;
 323         uloop_timeout_set(&conn->timer, 1000);
 324 }
 325
 326 static void ubus_auto_connect_cb(struct uloop_timeout *timeout)
 327 {
 328         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 329
 330         if (ubus_connect_ctx(&conn->ctx, conn->path)) {
 331                 uloop_timeout_set(timeout, 1000);
 332                 fprintf(stderr, "failed to connect to ubus\n");
 333                 return;
 334         }
 335         conn->ctx.connection_lost = ubus_auto_disconnect_cb;
 336         if (conn->cb)
 337                 conn->cb(&conn->ctx);
 338         ubus_add_uloop(&conn->ctx);
 339 }
 340
 341 void ubus_auto_connect(struct ubus_auto_conn *conn)
 342 {
 343         conn->timer.cb = ubus_auto_connect_cb;
 344         ubus_auto_connect_cb(&conn->timer);
 345 }
 346
 347 struct ubus_context *ubus_connect(const char *path)
 348 {
 349         struct ubus_context *ctx;
 350
 351         ctx = calloc(1, sizeof(*ctx));
 352         if (!ctx)
 353                 return NULL;
 354
 355         if (ubus_connect_ctx(ctx, path)) {
 356                 free(ctx);
 357                 ctx = NULL;
 358         }
 359
 360         return ctx;
 361 }
 362
 363 void ubus_shutdown(struct ubus_context *ctx)
 364 {
 365         blob_buf_free(&b);
 366         if (!ctx)
 367                 return;
 368         close(ctx->sock.fd);
 369         uloop_timeout_cancel(&ctx->pending_timer);
 370         free(ctx->msgbuf.data);
 371 }
 372
 373 void ubus_free(struct ubus_context *ctx)
 374 {
 375         ubus_shutdown(ctx);
 376         free(ctx);
 377 }