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 ubus_lookup(struct ubus_context *ctx, const char *path,
 149                 ubus_lookup_handler_t cb, void *priv)
 150 {
 151         struct ubus_lookup_request lookup;
 152
 153         blob_buf_init(&b, 0);
 154         if (path)
 155                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 156
 157         if (ubus_start_request(ctx, &lookup.req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 158                 return UBUS_STATUS_INVALID_ARGUMENT;
 159
 160         lookup.req.raw_data_cb = ubus_lookup_cb;
 161         lookup.req.priv = priv;
 162         lookup.cb = cb;
 163         return ubus_complete_request(ctx, &lookup.req, 0);
 164 }
 165
 166 static void ubus_lookup_id_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 167 {
 168         struct blob_attr **attr;
 169         uint32_t *id = req->priv;
 170
 171         attr = ubus_parse_msg(msg);
 172
 173         if (!attr[UBUS_ATTR_OBJID])
 174                 return;
 175
 176         *id = blob_get_u32(attr[UBUS_ATTR_OBJID]);
 177 }
 178
 179 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id)
 180 {
 181         struct ubus_request req;
 182
 183         blob_buf_init(&b, 0);
 184         if (path)
 185                 blob_put_string(&b, UBUS_ATTR_OBJPATH, path);
 186
 187         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_LOOKUP, 0) < 0)
 188                 return UBUS_STATUS_INVALID_ARGUMENT;
 189
 190         req.raw_data_cb = ubus_lookup_id_cb;
 191         req.priv = id;
 192
 193         return ubus_complete_request(ctx, &req, 0);
 194 }
 195
 196 static int ubus_event_cb(struct ubus_context *ctx, struct ubus_object *obj,
 197                          struct ubus_request_data *req,
 198                          const char *method, struct blob_attr *msg)
 199 {
 200         struct ubus_event_handler *ev;
 201
 202         ev = container_of(obj, struct ubus_event_handler, obj);
 203         ev->cb(ctx, ev, method, msg);
 204         return 0;
 205 }
 206
 207 static const struct ubus_method event_method = {
 208         .name = NULL,
 209         .handler = ubus_event_cb,
 210 };
 211
 212 int ubus_register_event_handler(struct ubus_context *ctx,
 213                                 struct ubus_event_handler *ev,
 214                                 const char *pattern)
 215 {
 216         struct ubus_object *obj = &ev->obj;
 217         struct blob_buf b2;
 218         int ret;
 219
 220         if (!obj->id) {
 221                 obj->methods = &event_method;
 222                 obj->n_methods = 1;
 223
 224                 if (!!obj->name ^ !!obj->type)
 225                         return UBUS_STATUS_INVALID_ARGUMENT;
 226
 227                 ret = ubus_add_object(ctx, obj);
 228                 if (ret)
 229                         return ret;
 230         }
 231
 232         /* use a second buffer, ubus_invoke() overwrites the primary one */
 233         memset(&b2, 0, sizeof(b2));
 234         blob_buf_init(&b2, 0);
 235         blobmsg_add_u32(&b2, "object", obj->id);
 236         if (pattern)
 237                 blobmsg_add_string(&b2, "pattern", pattern);
 238
 239         return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_EVENT, "register", b2.head,
 240                           NULL, NULL, 0);
 241 }
 242
 243 int ubus_send_event(struct ubus_context *ctx, const char *id,
 244                     struct blob_attr *data)
 245 {
 246         struct ubus_request req;
 247         void *s;
 248
 249         blob_buf_init(&b, 0);
 250         blob_put_int32(&b, UBUS_ATTR_OBJID, UBUS_SYSTEM_OBJECT_EVENT);
 251         blob_put_string(&b, UBUS_ATTR_METHOD, "send");
 252         s = blob_nest_start(&b, UBUS_ATTR_DATA);
 253         blobmsg_add_string(&b, "id", id);
 254         blobmsg_add_field(&b, BLOBMSG_TYPE_TABLE, "data", blob_data(data), blob_len(data));
 255         blob_nest_end(&b, s);
 256
 257         if (ubus_start_request(ctx, &req, b.head, UBUS_MSG_INVOKE, UBUS_SYSTEM_OBJECT_EVENT) < 0)
 258                 return UBUS_STATUS_INVALID_ARGUMENT;
 259
 260         return ubus_complete_request(ctx, &req, 0);
 261 }
 262
 263 static void ubus_default_connection_lost(struct ubus_context *ctx)
 264 {
 265         if (ctx->sock.registered)
 266                 uloop_end();
 267 }
 268
 269 struct ubus_context *ubus_connect(const char *path)
 270 {
 271         struct ubus_context *ctx;
 272
 273         ctx = calloc(1, sizeof(*ctx));
 274         if (!ctx)
 275                 return NULL;
 276
 277         ctx->sock.fd = -1;
 278         ctx->sock.cb = ubus_handle_data;
 279         ctx->connection_lost = ubus_default_connection_lost;
 280
 281         INIT_LIST_HEAD(&ctx->requests);
 282         INIT_LIST_HEAD(&ctx->pending);
 283         avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 284         if (ubus_reconnect(ctx, path)) {
 285                 free(ctx);
 286                 ctx = NULL;
 287         }
 288
 289         return ctx;
 290 }
 291
 292 void ubus_free(struct ubus_context *ctx)
 293 {
 294         close(ctx->sock.fd);
 295         free(ctx);
 296 }