output/raop: move NTP code to separate library

1 files changed, 135 insertions, 0 deletions

diff --git a/src/ntp_server.c b/src/ntp_server.c
new file mode 100644
index 000000000..3d8298f4a
--- /dev/null
+++ b/src/ntp_server.c
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2003-2011 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "ntp_server.h"
+
+#include <glib.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/time.h>
+
+#ifdef WIN32
+#define WINVER 0x0501
+#include <ws2tcpip.h>
+#include <winsock.h>
+#else
+#include <sys/select.h>
+#include <sys/socket.h>
+#endif
+
+/*
+ * Calculate the current NTP time, store it in the buffer.
+ */
+static void
+fill_int(unsigned char *buffer, uint32_t value)
+{
+	uint32_t be = GINT32_TO_BE(value);
+	memcpy(buffer, &be, sizeof(be));
+}
+
+/*
+ * Store time in the NTP format in the buffer
+ */
+static void
+fill_time_buffer_with_time(unsigned char *buffer, struct timeval *tout)
+{
+	unsigned long secs_to_baseline = 964697997;
+	double fraction;
+	unsigned long long_fraction;
+	unsigned long secs;
+
+	fraction = ((double) tout->tv_usec) / 1000000.0;
+	long_fraction = (unsigned long) (fraction * 256.0 * 256.0 * 256.0 * 256.0);
+	secs = secs_to_baseline + tout->tv_sec;
+	fill_int(buffer, secs);
+	fill_int(buffer + 4, long_fraction);
+}
+
+/*
+ * Calculate the current NTP time, store it in the buffer.
+ */
+static void
+fill_time_buffer(unsigned char *buffer)
+{
+	struct timeval current_time;
+
+	gettimeofday(&current_time,NULL);
+	fill_time_buffer_with_time(buffer, &current_time);
+}
+
+bool
+ntp_server_handle(struct ntp_server *ntp)
+{
+	unsigned char buf[32];
+	struct sockaddr addr;
+	int iter;
+	unsigned int addr_len = sizeof(addr);
+	int num_bytes = recvfrom(ntp->fd, buf, sizeof(buf), 0, &addr, &addr_len);
+	if (num_bytes == 0) {
+		return false;
+	}
+	fill_time_buffer(buf + 16);
+	// set to response
+	buf[1] = 0xd3;
+	// copy request
+	for (iter = 0; iter < 8; iter++) {
+		buf[8 + iter] = buf[24 + iter];
+	}
+	fill_time_buffer(buf + 24);
+
+	num_bytes = sendto(ntp->fd, buf, num_bytes, 0, &addr, addr_len);
+
+	return num_bytes == sizeof(buf);
+}
+
+bool
+ntp_server_check(struct ntp_server *ntp, struct timeval *tout)
+{
+	fd_set rdfds;
+	int fdmax = 0;
+
+	FD_ZERO(&rdfds);
+
+	FD_SET(ntp->fd, &rdfds);
+	fdmax = ntp->fd;
+	select(fdmax + 1, &rdfds,NULL, NULL, tout);
+	if (FD_ISSET(ntp->fd, &rdfds)) {
+		if (!ntp_server_handle(ntp)) {
+			g_debug("unable to send timing response\n");
+			return false;
+		}
+	}
+	return true;
+}
+
+void
+ntp_server_init(struct ntp_server *ntp)
+{
+	ntp->port = 6002;
+	ntp->fd = -1;
+}
+
+void
+ntp_server_close(struct ntp_server *ntp)
+{
+	if (ntp->fd >= 0)
+		close(ntp->fd);
+}