From dc6e68fb1c84fb4237f854e4a8d353a4dc14c63d Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Mon, 19 Sep 2011 13:36:24 +0200 Subject: [PATCH] ntp: Add skeleton for Simple NTP support --- Makefile.am | 2 +- src/connman.h | 4 + src/ntp.c | 382 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 387 insertions(+), 1 deletion(-) create mode 100644 src/ntp.c diff --git a/Makefile.am b/Makefile.am index 9b1b374..2117ade 100644 --- a/Makefile.am +++ b/Makefile.am @@ -77,7 +77,7 @@ src_connmand_SOURCES = $(gdbus_sources) $(gdhcp_sources) \ src/dhcp.c src/rtnl.c src/proxy.c \ src/utsname.c src/timeserver.c src/rfkill.c \ src/storage.c src/dbus.c src/config.c \ - src/technology.c src/counter.c \ + src/technology.c src/counter.c src/ntp.c \ src/session.c src/tethering.c src/wpad.c src/wispr.c \ src/stats.c src/iptables.c src/dnsproxy.c src/6to4.c diff --git a/src/connman.h b/src/connman.h index 18c29c5..79025a8 100644 --- a/src/connman.h +++ b/src/connman.h @@ -282,6 +282,10 @@ gboolean __connman_connection_update_gateway(void); void __connman_connection_gateway_activate(struct connman_service *service, enum connman_ipconfig_type type); +int __connman_ntp_start(const char *interface, const char *resolver, + const char *server); +void __connman_ntp_stop(const char *interface); + int __connman_wpad_init(void); void __connman_wpad_cleanup(void); int __connman_wpad_start(struct connman_service *service); diff --git a/src/ntp.c b/src/ntp.c new file mode 100644 index 0000000..32ae714 --- /dev/null +++ b/src/ntp.c @@ -0,0 +1,382 @@ +/* + * + * Connection Manager + * + * Copyright (C) 2007-2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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 St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +#include "connman.h" + +struct ntp_short { + uint16_t seconds; + uint16_t fraction; +} __attribute__ ((packed)); + +struct ntp_time { + uint32_t seconds; + uint32_t fraction; +} __attribute__ ((packed)); + +struct ntp_msg { + uint8_t flags; /* Mode, version and leap indicator */ + uint8_t stratum; /* Stratum details */ + int8_t poll; /* Maximum interval in log2 seconds */ + int8_t precision; /* Clock precision in log2 seconds */ + struct ntp_short rootdelay; /* Root delay */ + struct ntp_short rootdisp; /* Root dispersion */ + uint32_t refid; /* Reference ID */ + struct ntp_time reftime; /* Reference timestamp */ + struct ntp_time orgtime; /* Origin timestamp */ + struct ntp_time rectime; /* Receive timestamp */ + struct ntp_time xmttime; /* Transmit timestamp */ +} __attribute__ ((packed)); + +#define OFFSET_1900_1970 2208988800UL /* 1970 - 1900 in seconds */ + +#define STEPTIME_MIN_OFFSET 0.128 + +#define LOGTOD(a) ((a) < 0 ? 1. / (1L << -(a)) : 1L << (int)(a)) + +static struct timeval transmit_timeval; +static char *transmit_server; +static int transmit_fd; +static guint transmit_delay = 16; + +static void send_packet(int fd, const char *server) +{ + struct ntp_msg msg; + struct sockaddr_in addr; + ssize_t len; + + memset(&msg, 0, sizeof(msg)); + msg.flags = 0x23; + msg.poll = 4; // min + msg.poll = 10; // max + msg.xmttime.seconds = random(); + msg.xmttime.fraction = random(); + + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons(123); + addr.sin_addr.s_addr = inet_addr(server); + + gettimeofday(&transmit_timeval, NULL); + + len = sendto(fd, &msg, sizeof(msg), MSG_DONTWAIT, + &addr, sizeof(addr)); + if (len < 0) { + connman_error("Time request for server %s failed", server); + return; + } + + if (len != sizeof(msg)) { + connman_error("Broken time request for server %s", server); + return; + } +} + +static gboolean next_request(gpointer user_data) +{ + DBG("server %s", transmit_server); + + send_packet(transmit_fd, transmit_server); + + return FALSE; +} + +static void decode_msg(void *base, size_t len, struct timeval *tv) +{ + struct ntp_msg *msg = base; + double org, rec, xmt, dst; + double delay, offset; + + if (len < sizeof(*msg)) { + connman_error("Invalid response from time server"); + return; + } + + if (tv == NULL) { + connman_error("Invalid packet timestamp from time server"); + return; + } + + DBG("flags : 0x%02x", msg->flags); + DBG("stratum : %u", msg->stratum); + DBG("poll : %f seconds (%d)", + LOGTOD(msg->poll), msg->poll); + DBG("precision : %f seconds (%d)", + LOGTOD(msg->precision), msg->precision); + DBG("root delay : %u seconds (fraction %u)", + msg->rootdelay.seconds, msg->rootdelay.fraction); + DBG("root disp. : %u seconds (fraction %u)", + msg->rootdisp.seconds, msg->rootdisp.fraction); + DBG("reference : 0x%04x", msg->refid); + + transmit_delay = LOGTOD(msg->poll); + + if (msg->flags != 0x24) + return; + + org = transmit_timeval.tv_sec + + (1.0e-6 * transmit_timeval.tv_usec) + OFFSET_1900_1970; + rec = ntohl(msg->rectime.seconds) + + ((double) ntohl(msg->rectime.fraction) / UINT_MAX); + xmt = ntohl(msg->xmttime.seconds) + + ((double) ntohl(msg->xmttime.fraction) / UINT_MAX); + dst = tv->tv_sec + (1.0e-6 * tv->tv_usec) + OFFSET_1900_1970; + + DBG("org=%f rec=%f xmt=%f dst=%f", org, rec, xmt, dst); + + offset = ((rec - org) + (xmt - dst)) / 2; + delay = (dst - org) - (xmt - rec); + + DBG("offset=%f delay=%f", offset, delay); + + if (offset < STEPTIME_MIN_OFFSET && offset > -STEPTIME_MIN_OFFSET) { + struct timeval adj; + + adj.tv_sec = (long) offset; + adj.tv_usec = (offset - adj.tv_sec) * 1000000; + + DBG("adjusting time"); + + if (adjtime(&adj, &adj) < 0) { + connman_error("Failed to adjust time"); + return; + } + + DBG("%lu seconds, %lu msecs", adj.tv_sec, adj.tv_usec); + } else { + struct timeval cur; + double dtime; + + gettimeofday(&cur, NULL); + dtime = offset + cur.tv_sec + 1.0e-6 * cur.tv_usec; + cur.tv_sec = (long) dtime; + cur.tv_usec = (dtime - cur.tv_sec) * 1000000; + + DBG("setting time"); + + if (settimeofday(&cur, NULL) < 0) { + connman_error("Failed to set time"); + return; + } + + DBG("%lu seconds, %lu msecs", cur.tv_sec, cur.tv_usec); + } +} + +static guint channel_watch = 0; + +static gboolean received_data(GIOChannel *channel, GIOCondition condition, + gpointer user_data) +{ + unsigned char buf[128]; + struct msghdr msg; + struct iovec iov; + struct cmsghdr *cmsg; + struct timeval *tv; + char aux[128]; + ssize_t len; + int fd; + + if (condition & (G_IO_HUP | G_IO_ERR | G_IO_NVAL)) { + connman_error("Problem with timer server channel"); + channel_watch = 0; + return FALSE; + } + + fd = g_io_channel_unix_get_fd(channel); + + iov.iov_base = buf; + iov.iov_len = sizeof(buf); + + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = aux; + msg.msg_controllen = sizeof(aux); + + len = recvmsg(fd, &msg, MSG_DONTWAIT); + if (len < 0) + return TRUE; + + tv = NULL; + + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { + if (cmsg->cmsg_level != SOL_SOCKET) + continue; + + switch (cmsg->cmsg_type) { + case SCM_TIMESTAMP: + tv = (struct timeval *) CMSG_DATA(cmsg); + break; + } + } + + decode_msg(iov.iov_base, iov.iov_len, tv); + + g_timeout_add_seconds(transmit_delay, next_request, NULL); + + return TRUE; +} + +static void start_ntp(const char *server) +{ + GIOChannel *channel; + struct sockaddr_in addr; + int fd, tos = IPTOS_LOWDELAY, timestamp = 1; + + DBG("server %s", server); + + if (channel_watch > 0) + return; + + fd = socket(PF_INET, SOCK_DGRAM, 0); + if (fd < 0) { + connman_error("Failed to open time server socket"); + return; + } + + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + + if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { + connman_error("Failed to bind time server socket"); + close(fd); + return; + } + + if (setsockopt(fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) { + connman_error("Failed to set type of service option"); + close(fd); + return; + } + + if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMP, ×tamp, + sizeof(timestamp)) < 0) { + connman_error("Failed to enable timestamp support"); + close(fd); + return; + } + + channel = g_io_channel_unix_new(fd); + if (channel == NULL) { + close(fd); + return; + } + + g_io_channel_set_encoding(channel, NULL, NULL); + g_io_channel_set_buffered(channel, FALSE); + + g_io_channel_set_close_on_unref(channel, TRUE); + + channel_watch = g_io_add_watch_full(channel, G_PRIORITY_DEFAULT, + G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL, + received_data, NULL, NULL); + + g_io_channel_unref(channel); + + transmit_fd = fd; + transmit_server = g_strdup(server); + + send_packet(fd, server); +} + +static void resolv_debug(const char *str, void *data) +{ + connman_info("%s: %s\n", (const char *) data, str); +} + +static GResolv *resolv = NULL; +static guint resolv_lookup = 0; + +static void resolv_result(GResolvResultStatus status, + char **results, gpointer user_data) +{ + int i; + + resolv_lookup = 0; + + if (results != NULL) { + for (i = 0; results[i]; i++) + DBG("result: %s", results[i]); + + if (results[0] != NULL) + start_ntp(results[0]); + } +} + +int __connman_ntp_start(const char *interface, const char *resolver, + const char *server) +{ + DBG("interface %s server %s", interface, server); + + resolv = g_resolv_new(0); + if (resolv == NULL) + return -ENOMEM; + + if (getenv("CONNMAN_RESOLV_DEBUG")) + g_resolv_set_debug(resolv, resolv_debug, "RESOLV"); + + if (resolver != NULL) + g_resolv_add_nameserver(resolv, resolver, 53, 0); + + g_resolv_lookup_hostname(resolv, server, resolv_result, NULL); + + return 0; +} + +void __connman_ntp_stop(const char *interface) +{ + DBG("interface %s", interface); + + if (resolv == NULL) + return; + + if (resolv_lookup > 0) { + g_resolv_cancel_lookup(resolv, resolv_lookup); + resolv_lookup = 0; + } + + if (channel_watch > 0) { + g_source_remove(channel_watch); + channel_watch = 0; + } + + g_resolv_unref(resolv); +} -- 2.7.4