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 *hdr)
  75 {
  76         struct ubus_pending_msg *pending;
  77         void *data;
  78
  79         pending = calloc_a(sizeof(*pending),
  80                            &data, blob_raw_len(ubus_msghdr_data(hdr)));
  81
  82         pending->hdr.data = data;
  83         memcpy(&pending->hdr.hdr, hdr, sizeof(*hdr));
  84         memcpy(data, ubus_msghdr_data(hdr), blob_raw_len(ubus_msghdr_data(hdr)));
  85         list_add(&pending->list, &ctx->pending);
  86         if (ctx->sock.registered)
  87                 uloop_timeout_set(&ctx->pending_timer, 1);
  88 }
  89
  90 void __hidden
  91 ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr, int fd)
  92 {
  93
  94         switch(hdr->type) {
  95         case UBUS_MSG_STATUS:
  96         case UBUS_MSG_DATA:
  97                 ubus_process_req_msg(ctx, hdr, fd);
  98                 break;
  99
 100         case UBUS_MSG_INVOKE:
 101         case UBUS_MSG_UNSUBSCRIBE:
 102         case UBUS_MSG_NOTIFY:
 103                 if (ctx->stack_depth) {
 104                         ubus_queue_msg(ctx, hdr);
 105                         break;
 106                 }
 107
 108                 ubus_process_obj_msg(ctx, hdr);
 109                 break;
 110         }
 111 }
 112
 113 static void ubus_process_pending_msg(struct uloop_timeout *timeout)
 114 {
 115         struct ubus_context *ctx = container_of(timeout, struct ubus_context, pending_timer);
 116         struct ubus_pending_msg *pending;
 117
 118         while (!ctx->stack_depth && !list_empty(&ctx->pending)) {
 119                 pending = list_first_entry(&ctx->pending, struct ubus_pending_msg, list);
 120                 list_del(&pending->list);
 121                 ubus_process_msg(ctx, &pending->hdr.hdr, -1);
 122                 free(pending);
 123         }
 124 }
 125
 126 struct ubus_lookup_request {
 127         struct ubus_request req;
 128         ubus_lookup_handler_t cb;
 129 };
 130
 131 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 132 {
 133         struct ubus_lookup_request *req;
 134         struct ubus_object_data obj;
 135         struct blob_attr **attr;
 136
 137         req = container_of(ureq, struct ubus_lookup_request, req);
 138         attr = ubus_parse_msg(msg);
 139
 140         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 141             !attr[UBUS_ATTR_OBJTYPE])
 142                 return;
 143
 144         memset(&obj, 0, sizeof(obj));
 145         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 146         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 147         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 148         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 149         req->cb(ureq->ctx, &obj, ureq->priv);
 150 }
 151
 152 int ubus_lookup(struct ubus_context *ctx, const char *path,
 153                 ubus_lookup_handler_t cb, void *priv)
 154 {
 155         struct ubus_lookup_request lookup;
 156
 157         blob_buf_init(&b, 0);
 158         if (path)
 159                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 160
 161         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 162                 return UBUS_STATUS_INVALID_ARGUMENT;
 163
 164         lookup.req.raw_data_cb = ubus_lookup_cb;
 165         lookup.req.priv = priv;
 166         lookup.cb = cb;
 167         return ubus_complete_request(ctx, &lookup.req, 0);
 168 }
 169
 170 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 171 {
 172         struct blob_attr **attr;
 173         uint32_t *id = req->priv;
 174
 175         attr = ubus_parse_msg(msg);
 176
 177         if (!attr[UBUS_ATTR_OBJID])
 178                 return;
 179
 180         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 181 }
 182
 183 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 184 {
 185         struct ubus_request req;
 186
 187         blob_buf_init(&b, 0);
 188         if (path)
 189                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 190
 191         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 192                 return UBUS_STATUS_INVALID_ARGUMENT;
 193
 194         req.raw_data_cb = ubus_lookup_id_cb;
 195         req.priv = id;
 196
 197         return ubus_complete_request(ctx, &req, 0);
 198 }
 199
 200 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 201                          struct ubus_request_data *req,
 202                          const char *method, struct blob_attr *msg)
 203 {
 204         struct ubus_event_handler *ev;
 205
 206         ev = container_of(obj, struct ubus_event_handler, obj);
 207         ev->cb(ctx, ev, method, msg);
 208         return 0;
 209 }
 210
 211 static const struct ubus_method event_method = {
 212         .name = NULL,
 213         .handler = ubus_event_cb,
 214 };
 215
 216 int ubus_register_event_handler(struct ubus_context *ctx,
 217                                 struct ubus_event_handler *ev,
 218                                 const char *pattern)
 219 {
 220         struct ubus_object *obj = &ev->obj;
 221         struct blob_buf b2;
 222         int ret;
 223
 224         if (!obj->id) {
 225                 obj->methods = &event_method;
 226                 obj->n_methods = 1;
 227
 228                 if (!!obj->name ^ !!obj->type)
 229                         return UBUS_STATUS_INVALID_ARGUMENT;
 230
 231                 ret = ubus_add_object(ctx, obj);
 232                 if (ret)
 233                         return ret;
 234         }
 235
 236         /* use a second buffer, ubus_invoke() overwrites the primary one */
 237         memset(&b2, 0, sizeof(b2));
 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 static int _ubus_connect(struct ubus_context *ctx, const char *path)
 277 {
 278         ctx->sock.fd = -1;
 279         ctx->sock.cb = ubus_handle_data;
 280         ctx->connection_lost = ubus_default_connection_lost;
 281         ctx->pending_timer.cb = ubus_process_pending_msg;
 282
 283         ctx->msgbuf.data = calloc(UBUS_MSG_CHUNK_SIZE, sizeof(char));
 284         if (!ctx->msgbuf.data)
 285                 return -1;
 286         ctx->msgbuf_data_len = UBUS_MSG_CHUNK_SIZE;
 287
 288         INIT_LIST_HEAD(&ctx->requests);
 289         INIT_LIST_HEAD(&ctx->pending);
 290         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 291         if (ubus_reconnect(ctx, path)) {
 292                 free(ctx->msgbuf.data);
 293                 return -1;
 294         }
 295
 296         return 0;
 297 }
 298
 299 static void ubus_auto_reconnect_cb(struct uloop_timeout *timeout)
 300 {
 301         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 302
 303         if (!ubus_reconnect(&conn->ctx, conn->path))
 304                 ubus_add_uloop(&conn->ctx);
 305         else
 306                 uloop_timeout_set(timeout, 1000);
 307 }
 308
 309 static void ubus_auto_disconnect_cb(struct ubus_context *ctx)
 310 {
 311         struct ubus_auto_conn *conn = container_of(ctx, struct ubus_auto_conn, ctx);
 312
 313         conn->timer.cb = ubus_auto_reconnect_cb;
 314         uloop_timeout_set(&conn->timer, 1000);
 315 }
 316
 317 static void ubus_auto_connect_cb(struct uloop_timeout *timeout)
 318 {
 319         struct ubus_auto_conn *conn = container_of(timeout, struct ubus_auto_conn, timer);
 320
 321         if (_ubus_connect(&conn->ctx, conn->path)) {
 322                 uloop_timeout_set(timeout, 1000);
 323                 fprintf(stderr, "failed to connect to ubus\n");
 324                 return;
 325         }
 326         conn->ctx.connection_lost = ubus_auto_disconnect_cb;
 327         if (conn->cb)
 328                 conn->cb(&conn->ctx);
 329         ubus_add_uloop(&conn->ctx);
 330 }
 331
 332 void ubus_auto_connect(struct ubus_auto_conn *conn)
 333 {
 334         conn->timer.cb = ubus_auto_connect_cb;
 335         ubus_auto_connect_cb(&conn->timer);
 336 }
 337
 338 struct ubus_context *ubus_connect(const char *path)
 339 {
 340         struct ubus_context *ctx;
 341
 342         ctx = calloc(1, sizeof(*ctx));
 343         if (!ctx)
 344                 return NULL;
 345
 346         if (_ubus_connect(ctx, path)) {
 347                 free(ctx);
 348                 ctx = NULL;
 349         }
 350
 351         return ctx;
 352 }
 353
 354 void ubus_free(struct ubus_context *ctx)
 355 {
 356         blob_buf_free(&b);
 357         close(ctx->sock.fd);
 358         free(ctx->msgbuf.data);
 359         free(ctx);
 360 }