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         [UBUS_STATUS_NO_MEMORY] = "Out of memory",
  38         [UBUS_STATUS_PARSE_ERROR] = "Parsing message data failed",
  39         [UBUS_STATUS_SYSTEM_ERROR] = "System error",
  40 };
  41
  42 struct blob_buf b __hidden = {};
  43
  44 struct ubus_pending_msg {
  45         struct list_head list;
  46         struct ubus_msghdr_buf hdr;
  47 };
  48
  49 static int ubus_cmp_id(const void *k1, const void *k2, void *ptr)
  50 {
  51         const uint32_t *id1 = k1, *id2 = k2;
  52
  53         if (*id1 < *id2)
  54                 return -1;
  55         else
  56                 return *id1 > *id2;
  57 }
  58
  59 const char *ubus_strerror(int error)
  60 {
  61         static char err[32];
  62
  63         if (error < 0 || error >= __UBUS_STATUS_LAST)
  64                 goto out;
  65
  66         if (!__ubus_strerror[error])
  67                 goto out;
  68
  69         return __ubus_strerror[error];
  70
  71 out:
  72         sprintf(err, "Unknown error: %d", error);
  73         return err;
  74 }
  75
  76 static void
  77 ubus_queue_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf)
  78 {
  79         struct ubus_pending_msg *pending;
  80         void *data;
  81
  82         pending = calloc_a(sizeof(*pending), &data, blob_raw_len(buf->data));
  83
  84         pending->hdr.data = data;
  85         memcpy(&pending->hdr.hdr, &buf->hdr, sizeof(buf->hdr));
  86         memcpy(data, buf->data, blob_raw_len(buf->data));
  87         list_add_tail(&pending->list, &ctx->pending);
  88         if (ctx->sock.registered)
  89                 uloop_timeout_set(&ctx->pending_timer, 1);
  90 }
  91
  92 void __hidden
  93 ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
  94 {
  95         switch(buf->hdr.type) {
  96         case UBUS_MSG_STATUS:
  97         case UBUS_MSG_DATA:
  98                 ubus_process_req_msg(ctx, buf, fd);
  99                 break;
 100
 101         case UBUS_MSG_INVOKE:
 102         case UBUS_MSG_UNSUBSCRIBE:
 103         case UBUS_MSG_NOTIFY:
 104                 if (ctx->stack_depth) {
 105                         ubus_queue_msg(ctx, buf);
 106                         break;
 107                 }
 108
 109                 ctx->stack_depth++;
 110                 ubus_process_obj_msg(ctx, buf, fd);
 111                 ctx->stack_depth--;
 112                 break;
 113         case UBUS_MSG_MONITOR:
 114                 if (ctx->monitor_cb)
 115                         ctx->monitor_cb(ctx, buf->hdr.seq, buf->data);
 116                 break;
 117         }
 118 }
 119
 120 static void ubus_process_pending_msg(struct uloop_timeout *timeout)
 121 {
 122         struct ubus_context *ctx = container_of(timeout, struct ubus_context, pending_timer);
 123         struct ubus_pending_msg *pending;
 124
 125         while (!list_empty(&ctx->pending)) {
 126                 if (ctx->stack_depth)
 127                         break;
 128
 129                 pending = list_first_entry(&ctx->pending, struct ubus_pending_msg, list);
 130                 list_del(&pending->list);
 131                 ubus_process_msg(ctx, &pending->hdr, -1);
 132                 free(pending);
 133         }
 134 }
 135
 136 struct ubus_lookup_request {
 137         struct ubus_request req;
 138         ubus_lookup_handler_t cb;
 139 };
 140
 141 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 142 {
 143         struct ubus_lookup_request *req;
 144         struct ubus_object_data obj = {};
 145         struct blob_attr **attr;
 146
 147         req = container_of(ureq, struct ubus_lookup_request, req);
 148         attr = ubus_parse_msg(msg, blob_raw_len(msg));
 149
 150         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 151             !attr[UBUS_ATTR_OBJTYPE])
 152                 return;
 153
 154         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 155         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 156         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 157         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 158         req->cb(ureq->ctx, &obj, ureq->priv);
 159 }
 160
 161 int ubus_lookup(struct ubus_context *ctx, const char *path,
 162                 ubus_lookup_handler_t cb, void *priv)
 163 {
 164         struct ubus_lookup_request lookup;
 165
 166         blob_buf_init(&b, 0);
 167         if (path)
 168                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 169
 170         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 171                 return UBUS_STATUS_INVALID_ARGUMENT;
 172
 173         lookup.req.raw_data_cb = ubus_lookup_cb;
 174         lookup.req.priv = priv;
 175         lookup.cb = cb;
 176         return ubus_complete_request(ctx, &lookup.req, 0);
 177 }
 178
 179 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 180 {
 181         struct blob_attr **attr;
 182         uint32_t *id = req->priv;
 183
 184         attr = ubus_parse_msg(msg, blob_raw_len(msg));
 185
 186         if (!attr[UBUS_ATTR_OBJID])
 187                 return;
 188
 189         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 190 }
 191
 192 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 193 {
 194         struct ubus_request req;
 195
 196         blob_buf_init(&b, 0);
 197         if (path)
 198                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 199
 200         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 201                 return UBUS_STATUS_INVALID_ARGUMENT;
 202
 203         req.raw_data_cb = ubus_lookup_id_cb;
 204         req.priv = id;
 205
 206         return ubus_complete_request(ctx, &req, 0);
 207 }
 208
 209 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 210                          struct ubus_request_data *req,
 211                          const char *method, struct blob_attr *msg)
 212 {
 213         struct ubus_event_handler *ev;
 214
 215         ev = container_of(obj, struct ubus_event_handler, obj);
 216         ev->cb(ctx, ev, method, msg);
 217         return 0;
 218 }
 219
 220 static const struct ubus_method event_method = {
 221         .name = NULL,
 222         .handler = ubus_event_cb,
 223 };
 224
 225 int ubus_register_event_handler(struct ubus_context *ctx,
 226                                 struct ubus_event_handler *ev,
 227                                 const char *pattern)
 228 {
 229         struct ubus_object *obj = &ev->obj;
 230         struct blob_buf b2 = {};
 231         int ret;
 232
 233         if (!obj->id) {
 234                 obj->methods = &event_method;
 235                 obj->n_methods = 1;
 236
 237                 if (!!obj->name ^ !!obj->type)
 238                         return UBUS_STATUS_INVALID_ARGUMENT;
 239
 240                 ret = ubus_add_object(ctx, obj);
 241                 if (ret)
 242                         return ret;
 243         }
 244
 245         /* use a second buffer, ubus_invoke() overwrites the primary one */
 246         blob_buf_init(&b2, 0);
 247         blobmsg_add_u32(&b2, "object", obj->id);
 248         if (pattern)
 249                 blobmsg_add_string(&b2, "pattern", pattern);
 250
 251         ret = ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 252                           NULL, NULL, 0);
 253         blob_buf_free(&b2);
 254
 255         return ret;
 256 }
 257
 258 int ubus_send_event(struct ubus_context *ctx, const char *id,
 259                     struct blob_attr *data)
 260 {
 261         struct ubus_request req;
 262         void *s;
 263
 264         blob_buf_init(&b, 0);
 265         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 266         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 267         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 268         blobmsg_add_string(&b, "id", id);
 269         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 270         blob_nest_end(&b, s);
 271
 272         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 273                 return UBUS_STATUS_INVALID_ARGUMENT;
 274
 275         return ubus_complete_request(ctx, &req, 0);
 276 }
 277
 278 static void ubus_default_connection_lost(struct ubus_context *ctx)
 279 {
 280         if (ctx->sock.registered)
 281                 uloop_end();
 282 }
 283
 284 int ubus_connect_ctx(struct ubus_context *ctx, const char *path)
 285 {
 286         uloop_init();
 287         memset(ctx, 0, sizeof(*ctx));
 288
 289         ctx->sock.fd = -1;
 290         ctx->sock.cb = ubus_handle_data;
 291         ctx->connection_lost = ubus_default_connection_lost;
 292         ctx->pending_timer.cb = ubus_process_pending_msg;
 293
 294         ctx->msgbuf.data = calloc(1, UBUS_MSG_CHUNK_SIZE);
 295         if (!ctx->msgbuf.data)
 296                 return -1;
 297         ctx->msgbuf_data_len = UBUS_MSG_CHUNK_SIZE;
 298
 299         INIT_LIST_HEAD(&ctx->requests);
 300         INIT_LIST_HEAD(&ctx->pending);
 301         INIT_LIST_HEAD(&ctx->auto_subscribers);
 302         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 303         if (ubus_reconnect(ctx, path)) {
 304                 free(ctx->msgbuf.data);
 305                 ctx->msgbuf.data = NULL;
 306                 return -1;
 307         }
 308
 309         return 0;
 310 }
 311
 312 static void ubus_auto_reconnect_cb(struct uloop_timeout *timeout)
 313 {
 314         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 315
 316         if (!ubus_reconnect(&conn->ctx, conn->path))
 317                 ubus_add_uloop(&conn->ctx);
 318         else
 319                 uloop_timeout_set(timeout, 1000);
 320 }
 321
 322 static void ubus_auto_disconnect_cb(struct ubus_context *ctx)
 323 {
 324         struct ubus_auto_conn *conn = container_of(ctx, struct ubus_auto_conn, ctx);
 325
 326         conn->timer.cb = ubus_auto_reconnect_cb;
 327         uloop_timeout_set(&conn->timer, 1000);
 328 }
 329
 330 static void ubus_auto_connect_cb(struct uloop_timeout *timeout)
 331 {
 332         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 333
 334         if (ubus_connect_ctx(&conn->ctx, conn->path)) {
 335                 uloop_timeout_set(timeout, 1000);
 336                 fprintf(stderr, "failed to connect to ubus\n");
 337                 return;
 338         }
 339         conn->ctx.connection_lost = ubus_auto_disconnect_cb;
 340         if (conn->cb)
 341                 conn->cb(&conn->ctx);
 342         ubus_add_uloop(&conn->ctx);
 343 }
 344
 345 void ubus_auto_connect(struct ubus_auto_conn *conn)
 346 {
 347         conn->timer.cb = ubus_auto_connect_cb;
 348         ubus_auto_connect_cb(&conn->timer);
 349 }
 350
 351 struct ubus_context *ubus_connect(const char *path)
 352 {
 353         struct ubus_context *ctx;
 354
 355         ctx = calloc(1, sizeof(*ctx));
 356         if (!ctx)
 357                 return NULL;
 358
 359         if (ubus_connect_ctx(ctx, path)) {
 360                 free(ctx);
 361                 ctx = NULL;
 362         }
 363
 364         return ctx;
 365 }
 366
 367 void ubus_shutdown(struct ubus_context *ctx)
 368 {
 369         blob_buf_free(&b);
 370         if (!ctx)
 371                 return;
 372         uloop_fd_delete(&ctx->sock);
 373         close(ctx->sock.fd);
 374         uloop_timeout_cancel(&ctx->pending_timer);
 375         free(ctx->msgbuf.data);
 376 }
 377
 378 void ubus_free(struct ubus_context *ctx)
 379 {
 380         ubus_shutdown(ctx);
 381         free(ctx);
 382 }