Improve the UBus support in DNSMASQ:
- Aligned the handling of UBus connections with the DBus code as it makes it a
bit easier
to comprehend and allow for automatic reconnects when the connection to UBus
drops;
- make sure that DNSMASQ can connect to UBus when running as another user than
root;
- added status checks and logging to the various UBus calls to aid debugging
from an
enduser point of view;
- show the (lack of) support for UBus in the configuration string.
---
src/config.h | 4 ++
src/dnsmasq.c | 38 ++++++++++++++++-
src/dnsmasq.h | 6 +++
src/ubus.c | 114 ++++++++++++++++++++++++++++++++++++++++----------
4 files changed, 139 insertions(+), 23 deletions(-)
diff --git a/src/config.h b/src/config.h
index 203d69e..99b22eb 100644
--- a/src/config.h
+++ b/src/config.h
@@ -362,6 +362,10 @@ static char *compile_opts =
"no-"
#endif
"DBus "
+#ifndef HAVE_UBUS
+"no-"
+#endif
+"UBus "
#ifndef LOCALEDIR
"no-"
#endif
diff --git a/src/dnsmasq.c b/src/dnsmasq.c
index 3f3edbd..5d89aa1 100644
--- a/src/dnsmasq.c
+++ b/src/dnsmasq.c
@@ -420,6 +420,18 @@ int main (int argc, char **argv)
die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL,
EC_BADCONF);
#endif
+ if (option_bool(OPT_UBUS))
+#ifdef HAVE_UBUS
+ {
+ const char *err;
+ daemon->ubus = NULL;
+ if ((err = ubus_init()))
+ my_syslog(LOG_WARNING, _("UBus init failed: %s"), (char *)err,
EC_MISC);
+ }
+#else
+ die(_("UBus not available: set HAVE_UBUS in src/config.h"), NULL,
EC_BADCONF);
+#endif
+
if (daemon->port != 0)
pre_allocate_sfds();
@@ -812,6 +824,16 @@ int main (int argc, char **argv)
}
#endif
+#ifdef HAVE_UBUS
+ if (option_bool(OPT_UBUS))
+ {
+ if (daemon->ubus)
+ my_syslog(LOG_INFO, _("UBus support enabled: connected to system
bus"));
+ else
+ my_syslog(LOG_INFO, _("UBus support enabled: bus connection pending"));
+ }
+#endif
+
#ifdef HAVE_DNSSEC
if (option_bool(OPT_DNSSEC_VALID))
{
@@ -1000,7 +1022,7 @@ int main (int argc, char **argv)
#ifdef HAVE_UBUS
if (option_bool(OPT_UBUS))
- set_ubus_listeners();
+ set_ubus_listeners();
#endif
#ifdef HAVE_DHCP
@@ -1135,7 +1157,19 @@ int main (int argc, char **argv)
#ifdef HAVE_UBUS
if (option_bool(OPT_UBUS))
- check_ubus_listeners();
+ {
+ /* if we didn't create a UBus connection, retry now. */
+ if (!daemon->ubus)
+ {
+ const char *err;
+ if ((err = ubus_init()))
+ my_syslog(LOG_WARNING, _("UBus problem: %s"), err);
+ if (daemon->ubus)
+ my_syslog(LOG_INFO, _("Connected to system UBus"));
+ }
+
+ check_ubus_listeners();
+ }
#endif
check_dns_listeners(now);
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index 0e409b4..f5e154e 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -1119,6 +1119,11 @@ extern struct daemon {
#ifdef HAVE_DBUS
struct watch *watches;
#endif
+ /* UBus stuff */
+#ifdef HAVE_UBUS
+ /* void * here to avoid depending on ubus headers outside ubus.c */
+ void *ubus;
+#endif
/* TFTP stuff */
struct tftp_transfer *tftp_trans, *tftp_done_trans;
@@ -1456,6 +1461,7 @@ void emit_dbus_signal(int action, struct dhcp_lease
*lease, char
*hostname);
/* ubus.c */
#ifdef HAVE_UBUS
+const char *ubus_init(void);
void set_ubus_listeners(void);
void check_ubus_listeners(void);
void ubus_event_bcast(const char *type, const char *mac, const char *ip, const
char
*name, const char *interface);
diff --git a/src/ubus.c b/src/ubus.c
index 703a60d..c58c231 100644
--- a/src/ubus.c
+++ b/src/ubus.c
@@ -20,29 +20,94 @@
#include <libubus.h>
-static struct ubus_context *ubus = NULL;
static struct blob_buf b;
+static int notify;
static int ubus_handle_metrics(struct ubus_context *ctx, struct ubus_object
*obj,
struct ubus_request_data *req, const char
*method,
struct blob_attr *msg);
-static struct ubus_method ubus_object_methods[] = {
- {.name = "metrics", .handler = ubus_handle_metrics},
+
+static void ubus_subscribe_cb(struct ubus_context *ctx, struct ubus_object
*obj);
+
+static const struct ubus_method ubus_object_methods[] = {
+ UBUS_METHOD_NOARG("metrics", ubus_handle_metrics),
};
-static struct ubus_object_type ubus_object_type = UBUS_OBJECT_TYPE("dnsmasq",
ubus_object_methods);
+static struct ubus_object_type ubus_object_type =
+ UBUS_OBJECT_TYPE("dnsmasq", ubus_object_methods);
static struct ubus_object ubus_object = {
.name = "dnsmasq",
.type = &ubus_object_type,
.methods = ubus_object_methods,
.n_methods = ARRAY_SIZE(ubus_object_methods),
+ .subscribe_cb = ubus_subscribe_cb,
};
+static void ubus_subscribe_cb(struct ubus_context *ctx, struct ubus_object
*obj)
+{
+ (void)ctx;
+
+ my_syslog(LOG_DEBUG, _("UBus subscription callback: %s subscriber(s)"), obj-
>has_subscribers ? "1" : "0");
+ notify = obj->has_subscribers;
+}
+
+void ubus_destroy(struct ubus_context *ubus)
+{
+ // Forces re-initialization when we're reusing the same definitions later on.
+ ubus_object.id = 0;
+ ubus_object_type.id = 0;
+
+ ubus_free(ubus);
+ daemon->ubus = NULL;
+}
+
+static void ubus_disconnect_cb(struct ubus_context *ubus)
+{
+ int ret;
+
+ ret = ubus_reconnect(ubus, NULL);
+ if (ret)
+ {
+ my_syslog(LOG_ERR, _("Failed to reconnect to UBus: %s"),
ubus_strerror(ret));
+
+ ubus_destroy(ubus);
+ }
+}
+
+const char *ubus_init()
+{
+ struct ubus_context *ubus = NULL;
+ int ret;
+
+ ubus = ubus_connect(NULL);
+ if (!ubus)
+ {
+ ret = UBUS_STATUS_CONNECTION_FAILED;
+ return ubus_strerror(ret);
+ }
+
+ ubus->connection_lost = ubus_disconnect_cb;
+
+ ret = ubus_add_object(ubus, &ubus_object);
+ if (ret)
+ {
+ return ubus_strerror(ret);
+ }
+
+ daemon->ubus = ubus;
+
+ return NULL;
+}
+
void set_ubus_listeners()
{
+ struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
if (!ubus)
- return;
+ {
+ my_syslog(LOG_ERR, _("Cannot set UBus listeners: no connection"));
+ return;
+ }
poll_listen(ubus->sock.fd, POLLIN);
poll_listen(ubus->sock.fd, POLLERR);
@@ -51,46 +116,51 @@ void set_ubus_listeners()
void check_ubus_listeners()
{
+ struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
if (!ubus)
{
- ubus = ubus_connect(NULL);
- if (!ubus)
- return;
- ubus_add_object(ubus, &ubus_object);
+ my_syslog(LOG_ERR, _("Cannot poll UBus listeners: no connection"));
+ return;
}
if (poll_check(ubus->sock.fd, POLLIN))
ubus_handle_event(ubus);
- if (poll_check(ubus->sock.fd, POLLHUP))
+ if (poll_check(ubus->sock.fd, POLLHUP | POLLERR))
{
- ubus_free(ubus);
- ubus = NULL;
+ my_syslog(LOG_INFO, _("Disconnecting from UBus"));
+
+ ubus_destroy(ubus);
}
}
-
static int ubus_handle_metrics(struct ubus_context *ctx, struct ubus_object
*obj,
struct ubus_request_data *req, const char
*method,
struct blob_attr *msg)
{
int i;
- blob_buf_init(&b, 0);
- for(i=0; i < __METRIC_MAX; i++)
+ (void)obj;
+ (void)method;
+ (void)msg;
+
+ blob_buf_init(&b, BLOBMSG_TYPE_TABLE);
+
+ for (i=0; i < __METRIC_MAX; i++)
blobmsg_add_u32(&b, get_metric_name(i), daemon->metrics[i]);
- ubus_send_reply(ctx, req, b.head);
-
- return 0;
+ return ubus_send_reply(ctx, req, b.head);
}
void ubus_event_bcast(const char *type, const char *mac, const char *ip, const
char
*name, const char *interface)
{
- if (!ubus || !ubus_object.has_subscribers)
+ struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
+ int ret;
+
+ if (!ubus || !notify)
return;
- blob_buf_init(&b, 0);
+ blob_buf_init(&b, BLOBMSG_TYPE_TABLE);
if (mac)
blobmsg_add_string(&b, "mac", mac);
if (ip)
@@ -100,7 +170,9 @@ void ubus_event_bcast(const char *type, const char *mac,
const char
*ip, const c
if (interface)
blobmsg_add_string(&b, "interface", interface);
- ubus_notify(ubus, &ubus_object, type, b.head, -1);
+ ret = ubus_notify(ubus, &ubus_object, type, b.head, -1);
+ if (!ret)
+ my_syslog(LOG_ERR, _("Failed to send UBus event: %s"), ubus_strerror(ret));
}
--
2.20.1
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