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