libubus.c

   1 /*
   2  * Copyright (C) 2011-2012 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 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
  78         pending = calloc(1, sizeof(*pending) + blob_raw_len(hdr->data));
  79         if (!pending)
  80                 return;
  81
  82         memcpy(&pending->hdr, hdr, sizeof(*hdr) + blob_raw_len(hdr->data));
  83         list_add(&pending->list, &ctx->pending);
  84 }
  85
  86 void __hidden
  87 ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr *hdr)
  88 {
  89
  90         switch(hdr->type) {
  91         case UBUS_MSG_STATUS:
  92         case UBUS_MSG_DATA:
  93                 ubus_process_req_msg(ctx, hdr);
  94                 break;
  95
  96         case UBUS_MSG_INVOKE:
  97         case UBUS_MSG_UNSUBSCRIBE:
  98         case UBUS_MSG_NOTIFY:
  99                 if (ctx->stack_depth > 2) {
 100                         ubus_queue_msg(ctx, hdr);
 101                         break;
 102                 }
 103
 104                 ubus_process_obj_msg(ctx, hdr);
 105                 break;
 106         }
 107 }
 108
 109 void __hidden ubus_process_pending_msg(struct ubus_context *ctx)
 110 {
 111         struct ubus_pending_msg *pending, *tmp;
 112
 113         list_for_each_entry_safe(pending, tmp, &ctx->pending, list) {
 114                 list_del(&pending->list);
 115                 ubus_process_msg(ctx, &pending->hdr);
 116                 free(pending);
 117                 if (ctx->stack_depth > 2)
 118                         break;
 119         }
 120 }
 121
 122 struct ubus_lookup_request {
 123         struct ubus_request req;
 124         ubus_lookup_handler_t cb;
 125 };
 126
 127 static void ubus_lookup_cb(struct ubus_request *ureq, int type, struct blob_attr *msg)
 128 {
 129         struct ubus_lookup_request *req;
 130         struct ubus_object_data obj;
 131         struct blob_attr **attr;
 132
 133         req = container_of(ureq, struct ubus_lookup_request, req);
 134         attr = ubus_parse_msg(msg);
 135
 136         if (!attr[UBUS_ATTR_OBJID] || !attr[UBUS_ATTR_OBJPATH] ||
 137             !attr[UBUS_ATTR_OBJTYPE])
 138                 return;
 139
 140         memset(&obj, 0, sizeof(obj));
 141         obj.id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 142         obj.path = blob_data(attr[UBUS_ATTR_OBJPATH]);
 143         obj.type_id = blob_get_u32(attr[UBUS_ATTR_OBJTYPE]);
 144         obj.signature = attr[UBUS_ATTR_SIGNATURE];
 145         req->cb(ureq->ctx, &obj, ureq->priv);
 146 }
 147
 148 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 149                                 struct blob_attr *msg, int cmd, uint32_t peer)
 150 {
 151         memset(req, 0, sizeof(*req));
 152
 153         if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
 154                 return -1;
 155
 156         INIT_LIST_HEAD(&req->list);
 157         INIT_LIST_HEAD(&req->pending);
 158         req->ctx = ctx;
 159         req->peer = peer;
 160         req->seq = ++ctx->request_seq;
 161         return ubus_send_msg(ctx, req->seq, msg, cmd, peer);
 162 }
 163
 164 int ubus_lookup(struct ubus_context *ctx, const char *path,
 165                 ubus_lookup_handler_t cb, void *priv)
 166 {
 167         struct ubus_lookup_request lookup;
 168
 169         blob_buf_init(&b, 0);
 170         if (path)
 171                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 172
 173         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 174                 return UBUS_STATUS_INVALID_ARGUMENT;
 175
 176         lookup.req.raw_data_cb = ubus_lookup_cb;
 177         lookup.req.priv = priv;
 178         lookup.cb = cb;
 179         return ubus_complete_request(ctx, &lookup.req, 0);
 180 }
 181
 182 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 183 {
 184         struct blob_attr **attr;
 185         uint32_t *id = req->priv;
 186
 187         attr = ubus_parse_msg(msg);
 188
 189         if (!attr[UBUS_ATTR_OBJID])
 190                 return;
 191
 192         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 193 }
 194
 195 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 196 {
 197         struct ubus_request req;
 198
 199         blob_buf_init(&b, 0);
 200         if (path)
 201                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 202
 203         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 204                 return UBUS_STATUS_INVALID_ARGUMENT;
 205
 206         req.raw_data_cb = ubus_lookup_id_cb;
 207         req.priv = id;
 208
 209         return ubus_complete_request(ctx, &req, 0);
 210 }
 211
 212 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 213                          struct ubus_request_data *req,
 214                          const char *method, struct blob_attr *msg)
 215 {
 216         struct ubus_event_handler *ev;
 217
 218         ev = container_of(obj, struct ubus_event_handler, obj);
 219         ev->cb(ctx, ev, method, msg);
 220         return 0;
 221 }
 222
 223 static const struct ubus_method event_method = {
 224         .name = NULL,
 225         .handler = ubus_event_cb,
 226 };
 227
 228 int ubus_register_event_handler(struct ubus_context *ctx,
 229                                 struct ubus_event_handler *ev,
 230                                 const char *pattern)
 231 {
 232         struct ubus_object *obj = &ev->obj;
 233         struct blob_buf b2;
 234         int ret;
 235
 236         if (!obj->id) {
 237                 obj->methods = &event_method;
 238                 obj->n_methods = 1;
 239
 240                 if (!!obj->name ^ !!obj->type)
 241                         return UBUS_STATUS_INVALID_ARGUMENT;
 242
 243                 ret = ubus_add_object(ctx, obj);
 244                 if (ret)
 245                         return ret;
 246         }
 247
 248         /* use a second buffer, ubus_invoke() overwrites the primary one */
 249         memset(&b2, 0, sizeof(b2));
 250         blob_buf_init(&b2, 0);
 251         blobmsg_add_u32(&b2, "object", obj->id);
 252         if (pattern)
 253                 blobmsg_add_string(&b2, "pattern", pattern);
 254
 255         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 256                           NULL, NULL, 0);
 257 }
 258
 259 int ubus_send_event(struct ubus_context *ctx, const char *id,
 260                     struct blob_attr *data)
 261 {
 262         struct ubus_request req;
 263         void *s;
 264
 265         blob_buf_init(&b, 0);
 266         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 267         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 268         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 269         blobmsg_add_string(&b, "id", id);
 270         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 271         blob_nest_end(&b, s);
 272
 273         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 274                 return UBUS_STATUS_INVALID_ARGUMENT;
 275
 276         return ubus_complete_request(ctx, &req, 0);
 277 }
 278
 279 static void ubus_default_connection_lost(struct ubus_context *ctx)
 280 {
 281         if (ctx->sock.registered)
 282                 uloop_end();
 283 }
 284
 285 struct ubus_context *ubus_connect(const char *path)
 286 {
 287         struct ubus_context *ctx;
 288
 289         ctx = calloc(1, sizeof(*ctx));
 290         if (!ctx)
 291                 return NULL;
 292
 293         ctx->sock.fd = -1;
 294         ctx->sock.cb = ubus_handle_data;
 295         ctx->connection_lost = ubus_default_connection_lost;
 296
 297         INIT_LIST_HEAD(&ctx->requests);
 298         INIT_LIST_HEAD(&ctx->pending);
 299         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 300         if (ubus_reconnect(ctx, path)) {
 301                 free(ctx);
 302                 ctx = NULL;
 303         }
 304
 305         return ctx;
 306 }
 307
 308 void ubus_free(struct ubus_context *ctx)
 309 {
 310         close(ctx->sock.fd);
 311         free(ctx);
 312 }