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-rw-r--r--ntp_io.c610
1 files changed, 610 insertions, 0 deletions
diff --git a/ntp_io.c b/ntp_io.c
new file mode 100644
index 0000000..86e3f26
--- /dev/null
+++ b/ntp_io.c
@@ -0,0 +1,610 @@
+/*
+ chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Richard P. Curnow 1997-2003
+ * Copyright (C) Timo Teras 2009
+ * Copyright (C) Miroslav Lichvar 2009, 2013-2016, 2018-2021
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License 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 Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ **********************************************************************
+
+ =======================================================================
+
+ This file deals with the IO aspects of reading and writing NTP packets
+ */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "memory.h"
+#include "ntp_io.h"
+#include "ntp_core.h"
+#include "ntp_sources.h"
+#include "ptp.h"
+#include "sched.h"
+#include "socket.h"
+#include "local.h"
+#include "logging.h"
+#include "conf.h"
+#include "privops.h"
+#include "util.h"
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+#include "ntp_io_linux.h"
+#endif
+
+#define INVALID_SOCK_FD -1
+
+/* The server/peer and client sockets for IPv4 and IPv6 */
+static int server_sock_fd4;
+static int server_sock_fd6;
+static int client_sock_fd4;
+static int client_sock_fd6;
+
+/* Reference counters for server sockets to keep them open only when needed */
+static int server_sock_ref4;
+static int server_sock_ref6;
+
+/* Flag indicating we create a new connected client socket for each
+ server instead of sharing client_sock_fd4 and client_sock_fd6 */
+static int separate_client_sockets;
+
+/* Flag indicating the server sockets are not created dynamically when needed,
+ either to have a socket for client requests when separate client sockets
+ are disabled and client port is equal to server port, or the server port is
+ disabled */
+static int permanent_server_sockets;
+
+/* Flag indicating the server IPv4 socket is bound to an address */
+static int bound_server_sock_fd4;
+
+/* PTP event port, or 0 if disabled */
+static int ptp_port;
+
+/* Shared server/client sockets for NTP-over-PTP */
+static int ptp_sock_fd4;
+static int ptp_sock_fd6;
+
+/* Buffer for transmitted NTP-over-PTP messages */
+static PTP_NtpMessage *ptp_message;
+
+/* Flag indicating that we have been initialised */
+static int initialised=0;
+
+/* ================================================== */
+
+/* Forward prototypes */
+static void read_from_socket(int sock_fd, int event, void *anything);
+
+/* ================================================== */
+
+static int
+open_socket(int family, int local_port, int client_only, IPSockAddr *remote_addr)
+{
+ int sock_fd, sock_flags, dscp, events = SCH_FILE_INPUT;
+ IPSockAddr local_addr;
+ char *iface;
+
+ if (!SCK_IsIpFamilyEnabled(family))
+ return INVALID_SOCK_FD;
+
+ if (!client_only) {
+ CNF_GetBindAddress(family, &local_addr.ip_addr);
+ iface = CNF_GetBindNtpInterface();
+ } else {
+ CNF_GetBindAcquisitionAddress(family, &local_addr.ip_addr);
+ iface = CNF_GetBindAcquisitionInterface();
+ }
+
+ local_addr.port = local_port;
+
+ sock_flags = SCK_FLAG_RX_DEST_ADDR | SCK_FLAG_PRIV_BIND;
+ if (!client_only)
+ sock_flags |= SCK_FLAG_BROADCAST;
+
+ sock_fd = SCK_OpenUdpSocket(remote_addr, &local_addr, iface, sock_flags);
+ if (sock_fd < 0) {
+ if (!client_only)
+ LOG(LOGS_ERR, "Could not open NTP socket on %s", UTI_IPSockAddrToString(&local_addr));
+ return INVALID_SOCK_FD;
+ }
+
+ dscp = CNF_GetNtpDscp();
+ if (dscp > 0 && dscp < 64) {
+#ifdef IP_TOS
+ if (!SCK_SetIntOption(sock_fd, IPPROTO_IP, IP_TOS, dscp << 2))
+ ;
+#endif
+ }
+
+ if (!client_only && family == IPADDR_INET4 && local_addr.port > 0)
+ bound_server_sock_fd4 = local_addr.ip_addr.addr.in4 != INADDR_ANY;
+
+ /* Enable kernel/HW timestamping of packets */
+#ifdef HAVE_LINUX_TIMESTAMPING
+ if (!NIO_Linux_SetTimestampSocketOptions(sock_fd, client_only, &events))
+#endif
+ if (!SCK_EnableKernelRxTimestamping(sock_fd))
+ ;
+
+ /* Register handler for read and possibly exception events on the socket */
+ SCH_AddFileHandler(sock_fd, events, read_from_socket, NULL);
+
+ return sock_fd;
+}
+
+/* ================================================== */
+
+static int
+open_separate_client_socket(IPSockAddr *remote_addr)
+{
+ return open_socket(remote_addr->ip_addr.family, 0, 1, remote_addr);
+}
+
+/* ================================================== */
+
+static void
+close_socket(int sock_fd)
+{
+ if (sock_fd == INVALID_SOCK_FD)
+ return;
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+ NIO_Linux_NotifySocketClosing(sock_fd);
+#endif
+ SCH_RemoveFileHandler(sock_fd);
+ SCK_CloseSocket(sock_fd);
+}
+
+/* ================================================== */
+
+void
+NIO_Initialise(void)
+{
+ int server_port, client_port;
+
+ assert(!initialised);
+ initialised = 1;
+
+#ifdef PRIVOPS_BINDSOCKET
+ SCK_SetPrivBind(PRV_BindSocket);
+#endif
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+ NIO_Linux_Initialise();
+#else
+ if (1) {
+ CNF_HwTsInterface *conf_iface;
+ if (CNF_GetHwTsInterface(0, &conf_iface))
+ LOG_FATAL("HW timestamping not supported");
+ }
+#endif
+
+ server_port = CNF_GetNTPPort();
+ client_port = CNF_GetAcquisitionPort();
+
+ /* Use separate connected sockets if client port is negative */
+ separate_client_sockets = client_port < 0;
+ if (client_port < 0)
+ client_port = 0;
+
+ permanent_server_sockets = !server_port || (!separate_client_sockets &&
+ client_port == server_port);
+
+ server_sock_fd4 = INVALID_SOCK_FD;
+ server_sock_fd6 = INVALID_SOCK_FD;
+ client_sock_fd4 = INVALID_SOCK_FD;
+ client_sock_fd6 = INVALID_SOCK_FD;
+ server_sock_ref4 = 0;
+ server_sock_ref6 = 0;
+
+ if (permanent_server_sockets && server_port) {
+ server_sock_fd4 = open_socket(IPADDR_INET4, server_port, 0, NULL);
+ server_sock_fd6 = open_socket(IPADDR_INET6, server_port, 0, NULL);
+ }
+
+ if (!separate_client_sockets) {
+ if (client_port != server_port || !server_port) {
+ client_sock_fd4 = open_socket(IPADDR_INET4, client_port, 1, NULL);
+ client_sock_fd6 = open_socket(IPADDR_INET6, client_port, 1, NULL);
+ } else {
+ client_sock_fd4 = server_sock_fd4;
+ client_sock_fd6 = server_sock_fd6;
+ }
+ }
+
+ if ((server_port && permanent_server_sockets &&
+ server_sock_fd4 == INVALID_SOCK_FD && server_sock_fd6 == INVALID_SOCK_FD) ||
+ (!separate_client_sockets &&
+ client_sock_fd4 == INVALID_SOCK_FD && client_sock_fd6 == INVALID_SOCK_FD)) {
+ LOG_FATAL("Could not open NTP sockets");
+ }
+
+ ptp_port = CNF_GetPtpPort();
+ ptp_sock_fd4 = INVALID_SOCK_FD;
+ ptp_sock_fd6 = INVALID_SOCK_FD;
+ ptp_message = NULL;
+
+ if (ptp_port > 0) {
+ ptp_sock_fd4 = open_socket(IPADDR_INET4, ptp_port, 0, NULL);
+ ptp_sock_fd6 = open_socket(IPADDR_INET6, ptp_port, 0, NULL);
+ ptp_message = MallocNew(PTP_NtpMessage);
+ }
+}
+
+/* ================================================== */
+
+void
+NIO_Finalise(void)
+{
+ if (server_sock_fd4 != client_sock_fd4)
+ close_socket(client_sock_fd4);
+ close_socket(server_sock_fd4);
+ server_sock_fd4 = client_sock_fd4 = INVALID_SOCK_FD;
+
+ if (server_sock_fd6 != client_sock_fd6)
+ close_socket(client_sock_fd6);
+ close_socket(server_sock_fd6);
+ server_sock_fd6 = client_sock_fd6 = INVALID_SOCK_FD;
+
+ close_socket(ptp_sock_fd4);
+ close_socket(ptp_sock_fd6);
+ ptp_sock_fd4 = ptp_sock_fd6 = INVALID_SOCK_FD;
+ Free(ptp_message);
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+ NIO_Linux_Finalise();
+#endif
+
+ initialised = 0;
+}
+
+/* ================================================== */
+
+int
+NIO_OpenClientSocket(NTP_Remote_Address *remote_addr)
+{
+ switch (remote_addr->ip_addr.family) {
+ case IPADDR_INET4:
+ if (ptp_port > 0 && remote_addr->port == ptp_port)
+ return ptp_sock_fd4;
+ if (separate_client_sockets)
+ return open_separate_client_socket(remote_addr);
+ return client_sock_fd4;
+ case IPADDR_INET6:
+ if (ptp_port > 0 && remote_addr->port == ptp_port)
+ return ptp_sock_fd6;
+ if (separate_client_sockets)
+ return open_separate_client_socket(remote_addr);
+ return client_sock_fd6;
+ default:
+ return INVALID_SOCK_FD;
+ }
+}
+
+/* ================================================== */
+
+int
+NIO_OpenServerSocket(NTP_Remote_Address *remote_addr)
+{
+ switch (remote_addr->ip_addr.family) {
+ case IPADDR_INET4:
+ if (ptp_port > 0 && remote_addr->port == ptp_port)
+ return ptp_sock_fd4;
+ if (permanent_server_sockets)
+ return server_sock_fd4;
+ if (server_sock_fd4 == INVALID_SOCK_FD)
+ server_sock_fd4 = open_socket(IPADDR_INET4, CNF_GetNTPPort(), 0, NULL);
+ if (server_sock_fd4 != INVALID_SOCK_FD)
+ server_sock_ref4++;
+ return server_sock_fd4;
+ case IPADDR_INET6:
+ if (ptp_port > 0 && remote_addr->port == ptp_port)
+ return ptp_sock_fd6;
+ if (permanent_server_sockets)
+ return server_sock_fd6;
+ if (server_sock_fd6 == INVALID_SOCK_FD)
+ server_sock_fd6 = open_socket(IPADDR_INET6, CNF_GetNTPPort(), 0, NULL);
+ if (server_sock_fd6 != INVALID_SOCK_FD)
+ server_sock_ref6++;
+ return server_sock_fd6;
+ default:
+ return INVALID_SOCK_FD;
+ }
+}
+
+/* ================================================== */
+
+static int
+is_ptp_socket(int sock_fd)
+{
+ return ptp_port > 0 && sock_fd != INVALID_SOCK_FD &&
+ (sock_fd == ptp_sock_fd4 || sock_fd == ptp_sock_fd6);
+}
+
+/* ================================================== */
+
+void
+NIO_CloseClientSocket(int sock_fd)
+{
+ if (is_ptp_socket(sock_fd))
+ return;
+
+ if (separate_client_sockets)
+ close_socket(sock_fd);
+}
+
+/* ================================================== */
+
+void
+NIO_CloseServerSocket(int sock_fd)
+{
+ if (permanent_server_sockets || sock_fd == INVALID_SOCK_FD || is_ptp_socket(sock_fd))
+ return;
+
+ if (sock_fd == server_sock_fd4) {
+ if (--server_sock_ref4 <= 0) {
+ close_socket(server_sock_fd4);
+ server_sock_fd4 = INVALID_SOCK_FD;
+ }
+ } else if (sock_fd == server_sock_fd6) {
+ if (--server_sock_ref6 <= 0) {
+ close_socket(server_sock_fd6);
+ server_sock_fd6 = INVALID_SOCK_FD;
+ }
+ } else {
+ assert(0);
+ }
+}
+
+/* ================================================== */
+
+int
+NIO_IsServerSocket(int sock_fd)
+{
+ return sock_fd != INVALID_SOCK_FD &&
+ (sock_fd == server_sock_fd4 || sock_fd == server_sock_fd6 || is_ptp_socket(sock_fd));
+}
+
+/* ================================================== */
+
+int
+NIO_IsServerSocketOpen(void)
+{
+ return server_sock_fd4 != INVALID_SOCK_FD || server_sock_fd6 != INVALID_SOCK_FD ||
+ ptp_sock_fd4 != INVALID_SOCK_FD || ptp_sock_fd6 != INVALID_SOCK_FD;
+}
+
+/* ================================================== */
+
+int
+NIO_IsServerConnectable(NTP_Remote_Address *remote_addr)
+{
+ int sock_fd;
+
+ sock_fd = open_separate_client_socket(remote_addr);
+ if (sock_fd == INVALID_SOCK_FD)
+ return 0;
+
+ close_socket(sock_fd);
+
+ return 1;
+}
+
+/* ================================================== */
+
+static void
+process_message(SCK_Message *message, int sock_fd, int event)
+{
+ NTP_Local_Address local_addr;
+ NTP_Local_Timestamp local_ts;
+ struct timespec sched_ts;
+
+ SCH_GetLastEventTime(&local_ts.ts, &local_ts.err, NULL);
+ local_ts.source = NTP_TS_DAEMON;
+ sched_ts = local_ts.ts;
+
+ if (message->addr_type != SCK_ADDR_IP) {
+ DEBUG_LOG("Unexpected address type");
+ return;
+ }
+
+ local_addr.ip_addr = message->local_addr.ip;
+ local_addr.if_index = message->if_index;;
+ local_addr.sock_fd = sock_fd;
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+ if (NIO_Linux_ProcessMessage(message, &local_addr, &local_ts, event))
+ return;
+#else
+ if (!UTI_IsZeroTimespec(&message->timestamp.kernel)) {
+ LCL_CookTime(&message->timestamp.kernel, &local_ts.ts, &local_ts.err);
+ local_ts.source = NTP_TS_KERNEL;
+ }
+#endif
+
+ if (local_ts.source != NTP_TS_DAEMON)
+ DEBUG_LOG("Updated RX timestamp delay=%.9f tss=%u",
+ UTI_DiffTimespecsToDouble(&sched_ts, &local_ts.ts), local_ts.source);
+
+ if (!NIO_UnwrapMessage(message, sock_fd))
+ return;
+
+ /* Just ignore the packet if it's not of a recognized length */
+ if (message->length < NTP_HEADER_LENGTH || message->length > sizeof (NTP_Packet)) {
+ DEBUG_LOG("Unexpected length");
+ return;
+ }
+
+ NSR_ProcessRx(&message->remote_addr.ip, &local_addr, &local_ts, message->data, message->length);
+}
+
+/* ================================================== */
+
+static void
+read_from_socket(int sock_fd, int event, void *anything)
+{
+ SCK_Message *messages;
+ int i, received, flags = 0;
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+ if (NIO_Linux_ProcessEvent(sock_fd, event))
+ return;
+#endif
+
+ if (event == SCH_FILE_EXCEPTION) {
+#ifdef HAVE_LINUX_TIMESTAMPING
+ flags |= SCK_FLAG_MSG_ERRQUEUE;
+#else
+ assert(0);
+#endif
+ }
+
+ messages = SCK_ReceiveMessages(sock_fd, flags, &received);
+ if (!messages)
+ return;
+
+ for (i = 0; i < received; i++)
+ process_message(&messages[i], sock_fd, event);
+}
+
+/* ================================================== */
+
+int
+NIO_UnwrapMessage(SCK_Message *message, int sock_fd)
+{
+ PTP_NtpMessage *msg;
+
+ if (!is_ptp_socket(sock_fd))
+ return 1;
+
+ if (message->length <= PTP_NTP_PREFIX_LENGTH) {
+ DEBUG_LOG("Unexpected length");
+ return 0;
+ }
+
+ msg = message->data;
+
+ if (msg->header.type != PTP_TYPE_DELAY_REQ || msg->header.version != PTP_VERSION ||
+ ntohs(msg->header.length) != message->length ||
+ msg->header.domain != PTP_DOMAIN_NTP ||
+ ntohs(msg->header.flags) != PTP_FLAG_UNICAST ||
+ ntohs(msg->tlv_header.type) != PTP_TLV_NTP ||
+ ntohs(msg->tlv_header.length) != message->length - PTP_NTP_PREFIX_LENGTH) {
+ DEBUG_LOG("Unexpected PTP message");
+ return 0;
+ }
+
+ message->data = (char *)message->data + PTP_NTP_PREFIX_LENGTH;
+ message->length -= PTP_NTP_PREFIX_LENGTH;
+
+ DEBUG_LOG("Unwrapped PTP->NTP len=%d", message->length);
+
+ return 1;
+}
+
+/* ================================================== */
+
+static int
+wrap_message(SCK_Message *message, int sock_fd)
+{
+ assert(PTP_NTP_PREFIX_LENGTH == 48);
+
+ if (!is_ptp_socket(sock_fd))
+ return 1;
+
+ if (!ptp_message)
+ return 0;
+
+ if (message->length < NTP_HEADER_LENGTH ||
+ message->length + PTP_NTP_PREFIX_LENGTH > sizeof (*ptp_message)) {
+ DEBUG_LOG("Unexpected length");
+ return 0;
+ }
+
+ memset(ptp_message, 0, PTP_NTP_PREFIX_LENGTH);
+ ptp_message->header.type = PTP_TYPE_DELAY_REQ;
+ ptp_message->header.version = PTP_VERSION;
+ ptp_message->header.length = htons(PTP_NTP_PREFIX_LENGTH + message->length);
+ ptp_message->header.domain = PTP_DOMAIN_NTP;
+ ptp_message->header.flags = htons(PTP_FLAG_UNICAST);
+ ptp_message->tlv_header.type = htons(PTP_TLV_NTP);
+ ptp_message->tlv_header.length = htons(message->length);
+ memcpy((char *)ptp_message + PTP_NTP_PREFIX_LENGTH, message->data, message->length);
+
+ message->data = ptp_message;
+ message->length += PTP_NTP_PREFIX_LENGTH;
+
+ DEBUG_LOG("Wrapped NTP->PTP len=%d", message->length - PTP_NTP_PREFIX_LENGTH);
+
+ return 1;
+}
+
+/* ================================================== */
+/* Send a packet to remote address from local address */
+
+int
+NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr,
+ NTP_Local_Address *local_addr, int length, int process_tx)
+{
+ SCK_Message message;
+
+ assert(initialised);
+
+ if (local_addr->sock_fd == INVALID_SOCK_FD) {
+ DEBUG_LOG("No socket to send to %s", UTI_IPSockAddrToString(remote_addr));
+ return 0;
+ }
+
+ SCK_InitMessage(&message, SCK_ADDR_IP);
+
+ message.data = packet;
+ message.length = length;
+
+ if (!wrap_message(&message, local_addr->sock_fd))
+ return 0;
+
+ /* Specify remote address if the socket is not connected */
+ if (NIO_IsServerSocket(local_addr->sock_fd) || !separate_client_sockets) {
+ message.remote_addr.ip.ip_addr = remote_addr->ip_addr;
+ message.remote_addr.ip.port = remote_addr->port;
+ }
+
+ message.local_addr.ip = local_addr->ip_addr;
+
+ /* Don't require responses to non-link-local addresses to use the same
+ interface */
+ message.if_index = SCK_IsLinkLocalIPAddress(&message.remote_addr.ip.ip_addr) ?
+ local_addr->if_index : INVALID_IF_INDEX;
+
+#if !defined(HAVE_IN_PKTINFO) && defined(IP_SENDSRCADDR)
+ /* On FreeBSD a local IPv4 address cannot be specified on bound socket */
+ if (message.local_addr.ip.family == IPADDR_INET4 &&
+ (bound_server_sock_fd4 || !NIO_IsServerSocket(local_addr->sock_fd)))
+ message.local_addr.ip.family = IPADDR_UNSPEC;
+#endif
+
+#ifdef HAVE_LINUX_TIMESTAMPING
+ if (process_tx)
+ NIO_Linux_RequestTxTimestamp(&message, local_addr->sock_fd);
+#endif
+
+ if (!SCK_SendMessage(local_addr->sock_fd, &message, 0))
+ return 0;
+
+ return 1;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 03:44:37 +0000