diff options
| -rw-r--r-- | Makefile | 14 | ||||
| -rw-r--r-- | README | 23 | ||||
| -rw-r--r-- | reflector.c | 180 |
3 files changed, 217 insertions, 0 deletions
diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..84ef2aa --- /dev/null +++ b/Makefile @@ -0,0 +1,14 @@ +CFLAGS ?= -O2 -g -Wall +LDFLAGS ?= + +GIO_CFLAGS = $(shell pkg-config --cflags gio-2.0) +GIO_LDFLAGS = $(shell pkg-config --libs gio-2.0) + +all: reflector + +clean: + rm -f reflector + +reflector: reflector.c + $(CC) -o $@ $^ $(CFLAGS) $(GIO_CFLAGS) $(LDFLAGS) $(GIO_LDFLAGS) + @@ -0,0 +1,23 @@ +PTP Clock reflector +=================== + +Reflector takes packets from a PTP (IEEE1588:2008) clock running on PTP domain +0, and makes it available on PTP domain 1 and also changes the clock +identification accordingly. + +This allows making a local clock available on the network and reflecting it +back to the same machine for testing of PTP clock implementations. + +Locally you can run ptpd from http://ptpd.sourceforge.net with + ptpd -i eth0 -M -n -C +and a PTP slave clock, e.g. + http://cgit.freedesktop.org/~slomo/gstreamer/tree/tests/examples/ptp/ptp-print-times.c?h=ptp + ./ptp-print-times -d 1 + +Remotely you can run reflector with + ./reflector + +The PTP slave clock will now get the local clock time from the network with 2 +round-trip times between the local and remote machine added. If the PTP slave +clock implementation works correct, the difference between the local clock and +the "remote" PTP clock should be approximately 0. diff --git a/reflector.c b/reflector.c new file mode 100644 index 0000000..6c33c31 --- /dev/null +++ b/reflector.c @@ -0,0 +1,180 @@ +/* GStreamer + * Copyright (C) 2015 Sebastian Dröge <sebastian@centricular.com> + * + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, + * Boston, MA 02110-1301, USA. + */ + +#include <glib.h> +#include <gio/gio.h> + +static GSocketAddress *event_saddr, *general_saddr; +static GSocket *socket_event, *socket_general; + +static gboolean +have_socket_data_cb (GSocket * socket, GIOCondition condition, + gpointer user_data) +{ + gchar buffer[8192]; + gssize read; + gssize written; + GError *err = NULL; + guint domain, type; + gboolean forward = FALSE; + + read = g_socket_receive (socket, buffer, sizeof (buffer), NULL, &err); + if (read == -1) + g_error ("Failed to read from socket: %s", err->message); + + g_message ("Received %" G_GSSIZE_FORMAT " bytes from %s socket", read, + (socket == socket_event ? "event" : "general")); + + if (read < 34) { + g_message ("short read"); + return G_SOURCE_CONTINUE; + } + + domain = buffer[4]; + type = buffer[0] & 0x0f; + /* Change domain 0 to domain 1 and the other way around */ + if (domain == 0 && (type == 0x0 || type == 0x8 || type == 0xb || type == 0x9)) { + gint i; + + buffer[4] = 1; + + /* flip source clock id */ + for (i = 20; i < 28; i++) + buffer[i] = buffer[i] ^ 0xff; + + /* flip source clock id */ + for (i = 44; i < 52; i++) + buffer[i] = buffer[i] ^ 0xff; + + forward = TRUE; + } else if (domain == 1 && (type == 0x1)) { + gint i; + + buffer[4] = 0; + + /* flip source clock id */ + for (i = 20; i < 28; i++) + buffer[i] = buffer[i] ^ 0xff; + + forward = TRUE; + } + + if (forward) { + + written = + g_socket_send_to (socket, + (socket == socket_event ? event_saddr : general_saddr), buffer, + read, NULL, &err); + + if (written != read) + g_warning ("written %" G_GSIZE_FORMAT " != read %" G_GSIZE_FORMAT, + written, read); + } + + return G_SOURCE_CONTINUE; +} + +gint +main (gint argc, gchar ** argv) +{ + GMainLoop *loop; + GError *err = NULL; + GInetAddress *bind_addr, *mcast_addr; + GSocketAddress *bind_saddr; + GSource *socket_event_source, *socket_general_source; + + /* Create sockets */ + socket_event = + g_socket_new (G_SOCKET_FAMILY_IPV4, G_SOCKET_TYPE_DATAGRAM, + G_SOCKET_PROTOCOL_UDP, &err); + if (!socket_event) + g_error ("Couldn't create event socket: %s", err->message); + g_socket_set_multicast_loopback (socket_event, FALSE); + + socket_general = + g_socket_new (G_SOCKET_FAMILY_IPV4, G_SOCKET_TYPE_DATAGRAM, + G_SOCKET_PROTOCOL_UDP, &err); + if (!socket_general) + g_error ("Couldn't create general socket: %s", err->message); + g_socket_set_multicast_loopback (socket_general, FALSE); + + /* Bind sockets */ + bind_addr = g_inet_address_new_any (G_SOCKET_FAMILY_IPV4); + bind_saddr = g_inet_socket_address_new (bind_addr, 319); + if (!g_socket_bind (socket_event, bind_saddr, TRUE, &err)) + g_error ("Couldn't bind event socket: %s", err->message); + g_object_unref (bind_saddr); + bind_saddr = g_inet_socket_address_new (bind_addr, 320); + if (!g_socket_bind (socket_general, bind_saddr, TRUE, &err)) + g_error ("Couldn't bind general socket: %s", err->message); + g_object_unref (bind_saddr); + g_object_unref (bind_addr); + + /* Join multicast groups */ + mcast_addr = g_inet_address_new_from_string ("224.0.1.129"); + + /* Join multicast group without any interface */ + if (!g_socket_join_multicast_group (socket_event, mcast_addr, FALSE, NULL, + &err)) + g_error ("Couldn't join multicast group: %s", err->message); + if (!g_socket_join_multicast_group (socket_general, mcast_addr, FALSE, + NULL, &err)) + g_error ("Couldn't join multicast group: %s", err->message); + + event_saddr = g_inet_socket_address_new (mcast_addr, 319); + general_saddr = g_inet_socket_address_new (mcast_addr, 320); + + /* Create socket sources */ + socket_event_source = + g_socket_create_source (socket_event, G_IO_IN | G_IO_PRI, NULL); + g_source_set_priority (socket_event_source, G_PRIORITY_HIGH); + g_source_set_callback (socket_event_source, (GSourceFunc) have_socket_data_cb, + NULL, NULL); + g_source_attach (socket_event_source, NULL); + socket_general_source = + g_socket_create_source (socket_general, G_IO_IN | G_IO_PRI, NULL); + g_source_set_priority (socket_general_source, G_PRIORITY_DEFAULT); + g_source_set_callback (socket_general_source, + (GSourceFunc) have_socket_data_cb, NULL, NULL); + g_source_attach (socket_general_source, NULL); + + /* Get running */ + loop = g_main_loop_new (NULL, FALSE); + g_main_loop_run (loop); + g_main_loop_unref (loop); + + g_source_destroy (socket_event_source); + g_source_destroy (socket_general_source); + + /* Leave multicast groups */ + g_socket_leave_multicast_group (socket_event, mcast_addr, FALSE, NULL, NULL); + g_socket_leave_multicast_group (socket_general, mcast_addr, FALSE, NULL, + NULL); + g_object_unref (mcast_addr); + g_object_unref (event_saddr); + g_object_unref (general_saddr); + + g_socket_close (socket_event, NULL); + g_object_unref (socket_event); + g_socket_close (socket_general, NULL); + g_object_unref (socket_general); + + return 0; +} |