diff options
Diffstat (limited to 'src/ntp_server.c')
| -rw-r--r-- | src/ntp_server.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/src/ntp_server.c b/src/ntp_server.c new file mode 100644 index 000000000..f31a2d845 --- /dev/null +++ b/src/ntp_server.c @@ -0,0 +1,131 @@ +/* + * 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 "udp_server.h" + +#include <glib.h> +#include <assert.h> +#include <stddef.h> +#include <stdint.h> +#include <string.h> +#include <unistd.h> +#include <sys/time.h> + +#ifdef WIN32 +#include <ws2tcpip.h> +#include <winsock.h> +#else +#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(¤t_time,NULL); + fill_time_buffer_with_time(buffer, ¤t_time); +} + +static void +ntp_server_datagram(int fd, const void *data, size_t num_bytes, + const struct sockaddr *source_address, + size_t source_address_length, G_GNUC_UNUSED void *ctx) +{ + unsigned char buf[32]; + int iter; + + if (num_bytes > sizeof(buf)) + num_bytes = sizeof(buf); + memcpy(buf, data, num_bytes); + + 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); + + sendto(fd, (void *)buf, num_bytes, 0, + source_address, source_address_length); +} + +static const struct udp_server_handler ntp_server_handler = { + .datagram = ntp_server_datagram, +}; + +void +ntp_server_init(struct ntp_server *ntp) +{ + ntp->port = 6002; + ntp->udp = NULL; +} + +bool +ntp_server_open(struct ntp_server *ntp, GError **error_r) +{ + assert(ntp->udp == NULL); + + ntp->udp = udp_server_new(ntp->port, &ntp_server_handler, ntp, + error_r); + return ntp->udp != NULL; +} + +void +ntp_server_close(struct ntp_server *ntp) +{ + if (ntp->udp != NULL) { + udp_server_free(ntp->udp); + ntp->udp = NULL; + } +} |