For our usage, we need to have more informations sent over D-Bus such as the
interface
name, the vendor class identifier and the lease expiration time.
To achieve this, we add a new D-Bus signal "DhcpLeaseNotification" which
exports the
requested informations as a dictionnary.
It also has the advantage to be flexible if someone wants to add a new entry in
the
future.
Note: in order to get leases extradata be populated, we enabled this feature if
D-Bus
is enabled in configuration file (this was enabled in the past only if a script
was
ran on leases updates).
Here is an example of the obtained result with a Python3 program:
''' Define our D-Bus callback '''
def cb(action, ipaddr, hwaddr, hostname, info):
print(f'Action: {action}')
print(f'IP: {ipaddr}')
print(f'Hostname: {hostname}')
for k in info:
print(f'{k}: {info.get(k)}')
''' Connect to signal DhcpLeaseNotification on interface
uk.org.thekelleys.dnsmasq '''
DNSMasq.listen('DhcpLeaseNotification', callback=cb)
''' Run GLib loop '''
GLib.MainLoop().run()
''' When DNSMasq receives a DHCP request, here is the result: '''
Action: 3
IP: 192.168.1.100
Hostname: Nucleus.nucle.us
interface: br-mgmt
vendor_class: LaGrosseBiche
expiration: 1575667431
Signed-off-by: Victorien Molle
Signed-off-by: Florent Fourcot
---
dbus/DBus-interface | 9
src/dbus.c | 118 +++-
src/dnsmasq.h | 2 +-
src/lease.c | 2 +-
src/rfc2131.c | 12 ++---
5 files changed, 134 insertions(+), 9 deletions(-)
diff --git a/dbus/DBus-interface b/dbus/DBus-interface
index 954c5b9..ed42551 100644
--- a/dbus/DBus-interface
+++ b/dbus/DBus-interface
@@ -273,14 +273,23 @@ DhcpLeaseAdded
---
This signal is emitted when a DHCP lease for a given IP address is created.
+This will also trigger the DhcpLeaseNotification signal.
DhcpLeaseDeleted
This signal is emitted when a DHCP lease for a given IP address is deleted.
+This will also trigger the DhcpLeaseNotification signal.
DhcpLeaseUpdated
This signal is emitted when a DHCP lease for a given IP address is updated.
+This will also trigger the DhcpLeaseNotification signal.
+
+DhcpLeaseNotification
+-
+
+This signal is emitted when a DHCP lease action is triggered. It exports,
+as a dictionnary, more informations than the other signals.
diff --git a/src/dbus.c b/src/dbus.c
index c0ce903..c906e11 100644
--- a/src/dbus.c
+++ b/src/dbus.c
@@ -55,6 +55,7 @@ const char* introspection_xml_template =
"\n"
" \n"
"\n"
+#ifdef HAVE_DHCP
"\n"
" \n"
" \n"
@@ -70,7 +71,13 @@ const char* introspection_xml_template =
" \n"
" \n"
"\n"
-#ifdef HAVE_DHCP
+"\n"
+" \n"
+" \n"
+" \n"
+" \n"
+" \n"
+"\n"
"\n"
" \n"
" \n"
@@ -98,6 +105,12 @@ struct watch {
struct watch *next;
};
+struct lease_info {
+ char *key;
+ char *fmt;
+ char dbus_type;
+ DBusBasicValue value;
+};
static dbus_bool_t add_watch(DBusWatch *watch, void *data)
{
@@ -828,6 +841,106 @@ void check_dbus_listeners()
}
#ifdef HAVE_DHCP
+/*
+ As this function is called by emit_dbus_signal, we already have access to
ipaddr, hwaddr and hostname attributes
+ NOTE: connection attribute is currently not NULL as it is verified by
emit_dbus_signal
+*/
+void emit_dhcplease_notification(DBusConnection *connection, int action,
struct dhcp_lease *lease, char *ipaddr, char *hwaddr, char *hostname)
+{
+ DBusMessageIter array, dict, iter, variant;
+ dbus_uint64_t expires = lease->expires;
+ unsigned char *buf = lease->extradata;
+ dbus_int32_t act_type = action;
+ char interface[IF_NAMESIZE];
+ DBusMessage* message = NULL;
+ struct lease_info *info;
+ int fd = daemon->dhcpfd;
+#if defined(HAVE_SCRIPT) || defined(HAVE_DBUS)
+ char *vendor_class;
+ int allocated = 0;
+#endif
+
+#ifdef HAVE_DHCP6
+ if (!daemon->dhcp)
+fd = daemon->dhcp6fd;
+#endif
+
+ /* Get interface name */
+ if (!indextoname(fd, lease->last_interface, interface))
+interface[0] = 0;
+
+#if defined(HAVE_SCRIPT) || defined(HAVE_DBUS)
+ vendor_class = "";
+ /* As defined in rfc2131.c, the first data is the vendor class even if it is
empty */
+ if (buf && *buf != 0)
+{
+ vendor_class = (char*)whine_malloc(lease->extradata_len + 1);
+ if (vendor_class)
+{
+ allocated = 1;
+ strncpy(vendor_class, (const char*)buf, (lease->extradata_len));
+}
+ else
+{
+ vendor_class = "";
+}
+}
+#endif
+
+ struct lease_info infos[] = {{.key = "interface", .fmt = "s", .dbus_type =
DBUS_TYPE_STRING, .value.str = interface},
+#if defined(HAVE_SCRIPT) || defined(HAVE_DBUS)
+ {.key = "vendor_class", .fmt = "s", .dbus_type
= DBUS_TYPE_STRING, .value.str = vendor_class},
+#endif
+ {.key =
