package/network/services/dnsmasq/patches/0052-Improved-UBus-supported.patch

   1 From a2b8220f4e82e454bbc0013ee83ea3220111d92e Mon Sep 17 00:00:00 2001
   2 From: Jan Willem Janssen <j.w.janssen@lxtreme.nl>
   3 Date: Mon, 25 Mar 2019 12:42:23 +0100
   4 Subject: [PATCH 52/57] Improved UBus supported
   5
   6 - aligned the handling of UBus connections with the DBus code as it
   7 makes it a bit easier to comprehend;
   8 - added logging to the various UBus calls to aid debugging from an
   9 enduser point of view, but be careful to not flood the logs;
  10 - show the (lack of) support for UBus in the configuration string.
  11
  12 Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
  13 ---
  14  src/config.h  |   4 ++
  15  src/dnsmasq.c |  32 +++++++++++-
  16  src/dnsmasq.h |   6 +++
  17  src/ubus.c    | 138 ++++++++++++++++++++++++++++++++++++++++++--------
  18  4 files changed, 157 insertions(+), 23 deletions(-)
  19
  20 --- a/src/config.h
  21 +++ b/src/config.h
  22 @@ -362,6 +362,10 @@ static char *compile_opts =
  23  "no-"
  24  #endif
  25  "DBus "
  26 +#ifndef HAVE_UBUS
  27 +"no-"
  28 +#endif
  29 +"UBus "
  30  #ifndef LOCALEDIR
  31  "no-"
  32  #endif
  33 --- a/src/dnsmasq.c
  34 +++ b/src/dnsmasq.c
  35 @@ -420,6 +420,16 @@ int main (int argc, char **argv)
  36    die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF);
  37  #endif
  38
  39 +  if (option_bool(OPT_UBUS))
  40 +#ifdef HAVE_UBUS
  41 +    {
  42 +      daemon->ubus = NULL;
  43 +      ubus_init();
  44 +    }
  45 +#else
  46 +  die(_("UBus not available: set HAVE_UBUS in src/config.h"), NULL, EC_BADCONF);
  47 +#endif
  48 +
  49    if (daemon->port != 0)
  50      pre_allocate_sfds();
  51
  52 @@ -811,6 +821,16 @@ int main (int argc, char **argv)
  53      }
  54  #endif
  55
  56 +#ifdef HAVE_UBUS
  57 +  if (option_bool(OPT_UBUS))
  58 +    {
  59 +      if (daemon->ubus)
  60 +        my_syslog(LOG_INFO, _("UBus support enabled: connected to system bus"));
  61 +      else
  62 +        my_syslog(LOG_INFO, _("UBus support enabled: bus connection pending"));
  63 +    }
  64 +#endif
  65 +
  66  #ifdef HAVE_DNSSEC
  67    if (option_bool(OPT_DNSSEC_VALID))
  68      {
  69 @@ -999,7 +1019,7 @@ int main (int argc, char **argv)
  70
  71  #ifdef HAVE_UBUS
  72        if (option_bool(OPT_UBUS))
  73 -         set_ubus_listeners();
  74 +        set_ubus_listeners();
  75  #endif
  76
  77  #ifdef HAVE_DHCP
  78 @@ -1134,7 +1154,15 @@ int main (int argc, char **argv)
  79
  80  #ifdef HAVE_UBUS
  81        if (option_bool(OPT_UBUS))
  82 -        check_ubus_listeners();
  83 +        {
  84 +          /* if we didn't create a UBus connection, retry now. */
  85 +          if (!daemon->ubus)
  86 +            {
  87 +              ubus_init();
  88 +            }
  89 +
  90 +          check_ubus_listeners();
  91 +        }
  92  #endif
  93
  94        check_dns_listeners(now);
  95 --- a/src/dnsmasq.h
  96 +++ b/src/dnsmasq.h
  97 @@ -1130,6 +1130,11 @@ extern struct daemon {
  98  #ifdef HAVE_DBUS
  99    struct watch *watches;
 100  #endif
 101 +  /* UBus stuff */
 102 +#ifdef HAVE_UBUS
 103 +  /* void * here to avoid depending on ubus headers outside ubus.c */
 104 +  void *ubus;
 105 +#endif
 106
 107    /* TFTP stuff */
 108    struct tftp_transfer *tftp_trans, *tftp_done_trans;
 109 @@ -1467,6 +1472,7 @@ void emit_dbus_signal(int action, struct
 110
 111  /* ubus.c */
 112  #ifdef HAVE_UBUS
 113 +void ubus_init(void);
 114  void set_ubus_listeners(void);
 115  void check_ubus_listeners(void);
 116  void ubus_event_bcast(const char *type, const char *mac, const char *ip, const char *name, const char *interface);
 117 --- a/src/ubus.c
 118 +++ b/src/ubus.c
 119 @@ -20,29 +20,112 @@
 120
 121  #include <libubus.h>
 122
 123 -static struct ubus_context *ubus = NULL;
 124  static struct blob_buf b;
 125 +static int notify;
 126 +static int error_logged = 0;
 127
 128  static int ubus_handle_metrics(struct ubus_context *ctx, struct ubus_object *obj,
 129                                struct ubus_request_data *req, const char *method,
 130                                struct blob_attr *msg);
 131 -static struct ubus_method ubus_object_methods[] = {
 132 -  {.name = "metrics", .handler = ubus_handle_metrics},
 133 +
 134 +static void ubus_subscribe_cb(struct ubus_context *ctx, struct ubus_object *obj);
 135 +
 136 +static const struct ubus_method ubus_object_methods[] = {
 137 +  UBUS_METHOD_NOARG("metrics", ubus_handle_metrics),
 138  };
 139
 140 -static struct ubus_object_type ubus_object_type = UBUS_OBJECT_TYPE("dnsmasq", ubus_object_methods);
 141 +static struct ubus_object_type ubus_object_type =
 142 +  UBUS_OBJECT_TYPE("dnsmasq", ubus_object_methods);
 143
 144  static struct ubus_object ubus_object = {
 145    .name = "dnsmasq",
 146    .type = &ubus_object_type,
 147    .methods = ubus_object_methods,
 148    .n_methods = ARRAY_SIZE(ubus_object_methods),
 149 +  .subscribe_cb = ubus_subscribe_cb,
 150  };
 151
 152 +static void ubus_subscribe_cb(struct ubus_context *ctx, struct ubus_object *obj)
 153 +{
 154 +  (void)ctx;
 155 +
 156 +  my_syslog(LOG_DEBUG, _("UBus subscription callback: %s subscriber(s)"), obj->has_subscribers ? "1" : "0");
 157 +  notify = obj->has_subscribers;
 158 +}
 159 +
 160 +static void ubus_destroy(struct ubus_context *ubus)
 161 +{
 162 +  // Forces re-initialization when we're reusing the same definitions later on.
 163 +  ubus_object.id = 0;
 164 +  ubus_object_type.id = 0;
 165 +
 166 +  ubus_free(ubus);
 167 +  daemon->ubus = NULL;
 168 +}
 169 +
 170 +static void ubus_disconnect_cb(struct ubus_context *ubus)
 171 +{
 172 +  int ret;
 173 +
 174 +  ret = ubus_reconnect(ubus, NULL);
 175 +  if (ret)
 176 +    {
 177 +      my_syslog(LOG_ERR, _("Cannot reconnect to UBus: %s"), ubus_strerror(ret));
 178 +
 179 +      ubus_destroy(ubus);
 180 +    }
 181 +}
 182 +
 183 +void ubus_init()
 184 +{
 185 +  struct ubus_context *ubus = NULL;
 186 +  int ret = 0;
 187 +
 188 +  ubus = ubus_connect(NULL);
 189 +  if (!ubus)
 190 +    {
 191 +      if (!error_logged)
 192 +        {
 193 +          my_syslog(LOG_ERR, _("Cannot initialize UBus: connection failed"));
 194 +          error_logged = 1;
 195 +        }
 196 +
 197 +      ubus_destroy(ubus);
 198 +      return;
 199 +    }
 200 +
 201 +  ret = ubus_add_object(ubus, &ubus_object);
 202 +  if (ret)
 203 +    {
 204 +      if (!error_logged)
 205 +        {
 206 +          my_syslog(LOG_ERR, _("Cannot add object to UBus: %s"), ubus_strerror(ret));
 207 +          error_logged = 1;
 208 +        }
 209 +      return;
 210 +    }
 211 +
 212 +  ubus->connection_lost = ubus_disconnect_cb;
 213 +  daemon->ubus = ubus;
 214 +  error_logged = 0;
 215 +
 216 +  my_syslog(LOG_INFO, _("Connected to system UBus"));
 217 +}
 218 +
 219  void set_ubus_listeners()
 220  {
 221 +  struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
 222    if (!ubus)
 223 -    return;
 224 +    {
 225 +      if (!error_logged)
 226 +        {
 227 +          my_syslog(LOG_ERR, _("Cannot set UBus listeners: no connection"));
 228 +          error_logged = 1;
 229 +        }
 230 +      return;
 231 +    }
 232 +
 233 +  error_logged = 0;
 234
 235    poll_listen(ubus->sock.fd, POLLIN);
 236    poll_listen(ubus->sock.fd, POLLERR);
 237 @@ -51,46 +134,57 @@ void set_ubus_listeners()
 238
 239  void check_ubus_listeners()
 240  {
 241 +  struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
 242    if (!ubus)
 243      {
 244 -      ubus = ubus_connect(NULL);
 245 -      if (!ubus)
 246 -       return;
 247 -      ubus_add_object(ubus, &ubus_object);
 248 +      if (!error_logged)
 249 +        {
 250 +          my_syslog(LOG_ERR, _("Cannot poll UBus listeners: no connection"));
 251 +          error_logged = 1;
 252 +        }
 253 +      return;
 254      }
 255
 256 +  error_logged = 0;
 257 +
 258    if (poll_check(ubus->sock.fd, POLLIN))
 259      ubus_handle_event(ubus);
 260
 261 -  if (poll_check(ubus->sock.fd, POLLHUP))
 262 +  if (poll_check(ubus->sock.fd, POLLHUP | POLLERR))
 263      {
 264 -      ubus_free(ubus);
 265 -      ubus = NULL;
 266 +      my_syslog(LOG_INFO, _("Disconnecting from UBus"));
 267 +
 268 +      ubus_destroy(ubus);
 269      }
 270  }
 271
 272 -
 273  static int ubus_handle_metrics(struct ubus_context *ctx, struct ubus_object *obj,
 274                                struct ubus_request_data *req, const char *method,
 275                                struct blob_attr *msg)
 276  {
 277    int i;
 278 -  blob_buf_init(&b, 0);
 279
 280 -  for(i=0; i < __METRIC_MAX; i++)
 281 +  (void)obj;
 282 +  (void)method;
 283 +  (void)msg;
 284 +
 285 +  blob_buf_init(&b, BLOBMSG_TYPE_TABLE);
 286 +
 287 +  for (i=0; i < __METRIC_MAX; i++)
 288      blobmsg_add_u32(&b, get_metric_name(i), daemon->metrics[i]);
 289
 290 -  ubus_send_reply(ctx, req, b.head);
 291 -
 292 -  return 0;
 293 +  return ubus_send_reply(ctx, req, b.head);
 294  }
 295
 296  void ubus_event_bcast(const char *type, const char *mac, const char *ip, const char *name, const char *interface)
 297  {
 298 -  if (!ubus || !ubus_object.has_subscribers)
 299 +  struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
 300 +  int ret;
 301 +
 302 +  if (!ubus || !notify)
 303      return;
 304
 305 -  blob_buf_init(&b, 0);
 306 +  blob_buf_init(&b, BLOBMSG_TYPE_TABLE);
 307    if (mac)
 308      blobmsg_add_string(&b, "mac", mac);
 309    if (ip)
 310 @@ -100,7 +194,9 @@ void ubus_event_bcast(const char *type,
 311    if (interface)
 312      blobmsg_add_string(&b, "interface", interface);
 313
 314 -  ubus_notify(ubus, &ubus_object, type, b.head, -1);
 315 +  ret = ubus_notify(ubus, &ubus_object, type, b.head, -1);
 316 +  if (!ret)
 317 +    my_syslog(LOG_ERR, _("Failed to send UBus event: %s"), ubus_strerror(ret));
 318  }
 319
 320