diff options
Diffstat (limited to 'ntp_io_linux.c')
| -rw-r--r-- | ntp_io_linux.c | 863 |
1 files changed, 863 insertions, 0 deletions
diff --git a/ntp_io_linux.c b/ntp_io_linux.c new file mode 100644 index 0000000..819792a --- /dev/null +++ b/ntp_io_linux.c @@ -0,0 +1,863 @@ +/* + chronyd/chronyc - Programs for keeping computer clocks accurate. + + ********************************************************************** + * Copyright (C) Miroslav Lichvar 2016-2018 + * + * 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. + * + ********************************************************************** + + ======================================================================= + + Functions for NTP I/O specific to Linux + */ + +#include "config.h" + +#include "sysincl.h" + +#include <ifaddrs.h> +#include <linux/errqueue.h> +#include <linux/ethtool.h> +#include <linux/net_tstamp.h> +#include <linux/sockios.h> +#include <net/if.h> + +#include "array.h" +#include "conf.h" +#include "hwclock.h" +#include "local.h" +#include "logging.h" +#include "ntp_core.h" +#include "ntp_io.h" +#include "ntp_io_linux.h" +#include "ntp_sources.h" +#include "sched.h" +#include "sys_linux.h" +#include "util.h" + +union sockaddr_in46 { + struct sockaddr_in in4; +#ifdef FEAT_IPV6 + struct sockaddr_in6 in6; +#endif + struct sockaddr u; +}; + +struct Interface { + char name[IF_NAMESIZE]; + int if_index; + int phc_fd; + int phc_mode; + int phc_nocrossts; + /* Link speed in mbit/s */ + int link_speed; + /* Start of UDP data at layer 2 for IPv4 and IPv6 */ + int l2_udp4_ntp_start; + int l2_udp6_ntp_start; + /* Precision of PHC readings */ + double precision; + /* Compensation of errors in TX and RX timestamping */ + double tx_comp; + double rx_comp; + HCL_Instance clock; +}; + +/* Number of PHC readings per HW clock sample */ +#define PHC_READINGS 10 + +/* Minimum interval between PHC readings */ +#define MIN_PHC_POLL -6 + +/* Maximum acceptable offset between HW and daemon/kernel timestamp */ +#define MAX_TS_DELAY 1.0 + +/* Array of Interfaces */ +static ARR_Instance interfaces; + +/* RX/TX and TX-specific timestamping socket options */ +static int ts_flags; +static int ts_tx_flags; + +/* Flag indicating the socket options can't be changed in control messages */ +static int permanent_ts_options; + +/* When sending client requests to a close and fast server, it is possible that + a response will be received before the HW transmit timestamp of the request + itself. To avoid processing of the response without the HW timestamp, we + monitor events returned by select() and suspend reading of packets from the + receive queue for up to 200 microseconds. As the requests are normally + separated by at least 200 milliseconds, it is sufficient to monitor and + suspend one socket at a time. */ +static int monitored_socket; +static int suspended_socket; +static SCH_TimeoutID resume_timeout_id; + +#define RESUME_TIMEOUT 200.0e-6 + +/* Unbound socket keeping the kernel RX timestamping permanently enabled + in order to avoid a race condition between receiving a server response + and the kernel actually starting to timestamp received packets after + enabling the timestamping and sending a request */ +static int dummy_rxts_socket; + +#define INVALID_SOCK_FD -3 + +/* ================================================== */ + +static int +add_interface(CNF_HwTsInterface *conf_iface) +{ + struct ethtool_ts_info ts_info; + struct hwtstamp_config ts_config; + struct ifreq req; + int sock_fd, if_index, phc_fd, req_hwts_flags; + unsigned int i; + struct Interface *iface; + + /* Check if the interface was not already added */ + for (i = 0; i < ARR_GetSize(interfaces); i++) { + if (!strcmp(conf_iface->name, ((struct Interface *)ARR_GetElement(interfaces, i))->name)) + return 1; + } + + sock_fd = socket(AF_INET, SOCK_DGRAM, 0); + if (sock_fd < 0) + return 0; + + memset(&req, 0, sizeof (req)); + memset(&ts_info, 0, sizeof (ts_info)); + + if (snprintf(req.ifr_name, sizeof (req.ifr_name), "%s", conf_iface->name) >= + sizeof (req.ifr_name)) { + close(sock_fd); + return 0; + } + + if (ioctl(sock_fd, SIOCGIFINDEX, &req)) { + DEBUG_LOG("ioctl(%s) failed : %s", "SIOCGIFINDEX", strerror(errno)); + close(sock_fd); + return 0; + } + + if_index = req.ifr_ifindex; + + ts_info.cmd = ETHTOOL_GET_TS_INFO; + req.ifr_data = (char *)&ts_info; + + if (ioctl(sock_fd, SIOCETHTOOL, &req)) { + DEBUG_LOG("ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno)); + close(sock_fd); + return 0; + } + + req_hwts_flags = SOF_TIMESTAMPING_RX_HARDWARE | SOF_TIMESTAMPING_TX_HARDWARE | + SOF_TIMESTAMPING_RAW_HARDWARE; + if ((ts_info.so_timestamping & req_hwts_flags) != req_hwts_flags) { + DEBUG_LOG("HW timestamping not supported on %s", req.ifr_name); + close(sock_fd); + return 0; + } + + if (ts_info.phc_index < 0) { + DEBUG_LOG("PHC missing on %s", req.ifr_name); + close(sock_fd); + return 0; + } + + ts_config.flags = 0; + ts_config.tx_type = HWTSTAMP_TX_ON; + + switch (conf_iface->rxfilter) { + case CNF_HWTS_RXFILTER_ANY: +#ifdef HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP + if (ts_info.rx_filters & (1 << HWTSTAMP_FILTER_NTP_ALL)) + ts_config.rx_filter = HWTSTAMP_FILTER_NTP_ALL; + else +#endif + if (ts_info.rx_filters & (1 << HWTSTAMP_FILTER_ALL)) + ts_config.rx_filter = HWTSTAMP_FILTER_ALL; + else + ts_config.rx_filter = HWTSTAMP_FILTER_NONE; + break; + case CNF_HWTS_RXFILTER_NONE: + ts_config.rx_filter = HWTSTAMP_FILTER_NONE; + break; +#ifdef HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP + case CNF_HWTS_RXFILTER_NTP: + ts_config.rx_filter = HWTSTAMP_FILTER_NTP_ALL; + break; +#endif + default: + ts_config.rx_filter = HWTSTAMP_FILTER_ALL; + break; + } + + req.ifr_data = (char *)&ts_config; + + if (ioctl(sock_fd, SIOCSHWTSTAMP, &req)) { + DEBUG_LOG("ioctl(%s) failed : %s", "SIOCSHWTSTAMP", strerror(errno)); + close(sock_fd); + return 0; + } + + close(sock_fd); + + phc_fd = SYS_Linux_OpenPHC(NULL, ts_info.phc_index); + if (phc_fd < 0) + return 0; + + iface = ARR_GetNewElement(interfaces); + + snprintf(iface->name, sizeof (iface->name), "%s", conf_iface->name); + iface->if_index = if_index; + iface->phc_fd = phc_fd; + iface->phc_mode = 0; + iface->phc_nocrossts = conf_iface->nocrossts; + + /* Start with 1 gbit and no VLANs or IPv4/IPv6 options */ + iface->link_speed = 1000; + iface->l2_udp4_ntp_start = 42; + iface->l2_udp6_ntp_start = 62; + + iface->precision = conf_iface->precision; + iface->tx_comp = conf_iface->tx_comp; + iface->rx_comp = conf_iface->rx_comp; + + iface->clock = HCL_CreateInstance(conf_iface->min_samples, conf_iface->max_samples, + UTI_Log2ToDouble(MAX(conf_iface->minpoll, MIN_PHC_POLL))); + + LOG(LOGS_INFO, "Enabled HW timestamping %son %s", + ts_config.rx_filter == HWTSTAMP_FILTER_NONE ? "(TX only) " : "", iface->name); + + return 1; +} + +/* ================================================== */ + +static int +add_all_interfaces(CNF_HwTsInterface *conf_iface_all) +{ + CNF_HwTsInterface conf_iface; + struct ifaddrs *ifaddr, *ifa; + int r; + + conf_iface = *conf_iface_all; + + if (getifaddrs(&ifaddr)) { + DEBUG_LOG("getifaddrs() failed : %s", strerror(errno)); + return 0; + } + + for (r = 0, ifa = ifaddr; ifa; ifa = ifa->ifa_next) { + conf_iface.name = ifa->ifa_name; + if (add_interface(&conf_iface)) + r = 1; + } + + freeifaddrs(ifaddr); + + /* Return success if at least one interface was added */ + return r; +} + +/* ================================================== */ + +static void +update_interface_speed(struct Interface *iface) +{ + struct ethtool_cmd cmd; + struct ifreq req; + int sock_fd, link_speed; + + sock_fd = socket(AF_INET, SOCK_DGRAM, 0); + if (sock_fd < 0) + return; + + memset(&req, 0, sizeof (req)); + memset(&cmd, 0, sizeof (cmd)); + + snprintf(req.ifr_name, sizeof (req.ifr_name), "%s", iface->name); + cmd.cmd = ETHTOOL_GSET; + req.ifr_data = (char *)&cmd; + + if (ioctl(sock_fd, SIOCETHTOOL, &req)) { + DEBUG_LOG("ioctl(%s) failed : %s", "SIOCETHTOOL", strerror(errno)); + close(sock_fd); + return; + } + + close(sock_fd); + + link_speed = ethtool_cmd_speed(&cmd); + + if (iface->link_speed != link_speed) { + iface->link_speed = link_speed; + DEBUG_LOG("Updated speed of %s to %d Mb/s", iface->name, link_speed); + } +} + +/* ================================================== */ + +#if defined(HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO) || defined(HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW) +static int +check_timestamping_option(int option) +{ + int sock_fd; + + sock_fd = socket(AF_INET, SOCK_DGRAM, 0); + if (sock_fd < 0) + return 0; + + if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPING, &option, sizeof (option)) < 0) { + DEBUG_LOG("Could not enable timestamping option %x", (unsigned int)option); + close(sock_fd); + return 0; + } + + close(sock_fd); + return 1; +} +#endif + +/* ================================================== */ + +static int +open_dummy_socket(void) +{ + int sock_fd, events = 0; + + if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0 +#ifdef FEAT_IPV6 + && (sock_fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0 +#endif + ) + return INVALID_SOCK_FD; + + if (!NIO_Linux_SetTimestampSocketOptions(sock_fd, 1, &events)) { + close(sock_fd); + return INVALID_SOCK_FD; + } + + UTI_FdSetCloexec(sock_fd); + return sock_fd; +} + +/* ================================================== */ + +void +NIO_Linux_Initialise(void) +{ + CNF_HwTsInterface *conf_iface; + unsigned int i; + int hwts; + + interfaces = ARR_CreateInstance(sizeof (struct Interface)); + + /* Enable HW timestamping on specified interfaces. If "*" was specified, try + all interfaces. If no interface was specified, enable SW timestamping. */ + + for (i = hwts = 0; CNF_GetHwTsInterface(i, &conf_iface); i++) { + if (!strcmp("*", conf_iface->name)) + continue; + if (!add_interface(conf_iface)) + LOG_FATAL("Could not enable HW timestamping on %s", conf_iface->name); + hwts = 1; + } + + for (i = 0; CNF_GetHwTsInterface(i, &conf_iface); i++) { + if (strcmp("*", conf_iface->name)) + continue; + if (add_all_interfaces(conf_iface)) + hwts = 1; + break; + } + + ts_flags = SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_RX_SOFTWARE; + ts_tx_flags = SOF_TIMESTAMPING_TX_SOFTWARE; + + if (hwts) { + ts_flags |= SOF_TIMESTAMPING_RAW_HARDWARE | SOF_TIMESTAMPING_RX_HARDWARE; + ts_tx_flags |= SOF_TIMESTAMPING_TX_HARDWARE; +#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO + if (check_timestamping_option(SOF_TIMESTAMPING_OPT_PKTINFO)) + ts_flags |= SOF_TIMESTAMPING_OPT_PKTINFO; +#endif +#ifdef HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW + if (check_timestamping_option(SOF_TIMESTAMPING_OPT_TX_SWHW)) + ts_flags |= SOF_TIMESTAMPING_OPT_TX_SWHW; +#endif + } + + /* Enable IP_PKTINFO in messages looped back to the error queue */ + ts_flags |= SOF_TIMESTAMPING_OPT_CMSG; + + /* Kernels before 4.7 ignore timestamping flags set in control messages */ + permanent_ts_options = !SYS_Linux_CheckKernelVersion(4, 7); + + monitored_socket = INVALID_SOCK_FD; + suspended_socket = INVALID_SOCK_FD; + dummy_rxts_socket = INVALID_SOCK_FD; +} + +/* ================================================== */ + +void +NIO_Linux_Finalise(void) +{ + struct Interface *iface; + unsigned int i; + + if (dummy_rxts_socket != INVALID_SOCK_FD) + close(dummy_rxts_socket); + + for (i = 0; i < ARR_GetSize(interfaces); i++) { + iface = ARR_GetElement(interfaces, i); + HCL_DestroyInstance(iface->clock); + close(iface->phc_fd); + } + + ARR_DestroyInstance(interfaces); +} + +/* ================================================== */ + +int +NIO_Linux_SetTimestampSocketOptions(int sock_fd, int client_only, int *events) +{ + int val, flags; + + if (!ts_flags) + return 0; + + /* Enable SCM_TIMESTAMPING control messages and the socket's error queue in + order to receive our transmitted packets with more accurate timestamps */ + + val = 1; + flags = ts_flags; + + if (client_only || permanent_ts_options) + flags |= ts_tx_flags; + + if (setsockopt(sock_fd, SOL_SOCKET, SO_SELECT_ERR_QUEUE, &val, sizeof (val)) < 0) { + LOG(LOGS_ERR, "Could not set %s socket option", "SO_SELECT_ERR_QUEUE"); + ts_flags = 0; + return 0; + } + + if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPING, &flags, sizeof (flags)) < 0) { + LOG(LOGS_ERR, "Could not set %s socket option", "SO_TIMESTAMPING"); + ts_flags = 0; + return 0; + } + + *events |= SCH_FILE_EXCEPTION; + return 1; +} + +/* ================================================== */ + +static void +resume_socket(int sock_fd) +{ + if (monitored_socket == sock_fd) + monitored_socket = INVALID_SOCK_FD; + + if (sock_fd == INVALID_SOCK_FD || sock_fd != suspended_socket) + return; + + suspended_socket = INVALID_SOCK_FD; + + SCH_SetFileHandlerEvent(sock_fd, SCH_FILE_INPUT, 1); + + DEBUG_LOG("Resumed RX processing %s timeout fd=%d", + resume_timeout_id ? "before" : "on", sock_fd); + + if (resume_timeout_id) { + SCH_RemoveTimeout(resume_timeout_id); + resume_timeout_id = 0; + } +} + +/* ================================================== */ + +static void +resume_timeout(void *arg) +{ + resume_timeout_id = 0; + resume_socket(suspended_socket); +} + +/* ================================================== */ + +static void +suspend_socket(int sock_fd) +{ + resume_socket(suspended_socket); + + suspended_socket = sock_fd; + + SCH_SetFileHandlerEvent(suspended_socket, SCH_FILE_INPUT, 0); + resume_timeout_id = SCH_AddTimeoutByDelay(RESUME_TIMEOUT, resume_timeout, NULL); + + DEBUG_LOG("Suspended RX processing fd=%d", sock_fd); +} + +/* ================================================== */ + +int +NIO_Linux_ProcessEvent(int sock_fd, int event) +{ + if (sock_fd != monitored_socket) + return 0; + + if (event == SCH_FILE_INPUT) { + suspend_socket(monitored_socket); + monitored_socket = INVALID_SOCK_FD; + + /* Don't process the message yet */ + return 1; + } + + return 0; +} + +/* ================================================== */ + +static struct Interface * +get_interface(int if_index) +{ + struct Interface *iface; + unsigned int i; + + for (i = 0; i < ARR_GetSize(interfaces); i++) { + iface = ARR_GetElement(interfaces, i); + if (iface->if_index != if_index) + continue; + + return iface; + } + + return NULL; +} + +/* ================================================== */ + +static void +process_hw_timestamp(struct Interface *iface, struct timespec *hw_ts, + NTP_Local_Timestamp *local_ts, int rx_ntp_length, int family, + int l2_length) +{ + struct timespec sample_phc_ts, sample_sys_ts, sample_local_ts, ts; + double rx_correction, ts_delay, phc_err, local_err; + + if (HCL_NeedsNewSample(iface->clock, &local_ts->ts)) { + if (!SYS_Linux_GetPHCSample(iface->phc_fd, iface->phc_nocrossts, iface->precision, + &iface->phc_mode, &sample_phc_ts, &sample_sys_ts, + &phc_err)) + return; + + LCL_CookTime(&sample_sys_ts, &sample_local_ts, &local_err); + HCL_AccumulateSample(iface->clock, &sample_phc_ts, &sample_local_ts, + phc_err + local_err); + + update_interface_speed(iface); + } + + /* We need to transpose RX timestamps as hardware timestamps are normally + preamble timestamps and RX timestamps in NTP are supposed to be trailer + timestamps. If we don't know the length of the packet at layer 2, we + make an assumption that UDP data start at the same position as in the + last transmitted packet which had a HW TX timestamp. */ + if (rx_ntp_length && iface->link_speed) { + if (!l2_length) + l2_length = (family == IPADDR_INET4 ? iface->l2_udp4_ntp_start : + iface->l2_udp6_ntp_start) + rx_ntp_length + 4; + rx_correction = l2_length / (1.0e6 / 8 * iface->link_speed); + + UTI_AddDoubleToTimespec(hw_ts, rx_correction, hw_ts); + } + + if (!HCL_CookTime(iface->clock, hw_ts, &ts, &local_err)) + return; + + if (!rx_ntp_length && iface->tx_comp) + UTI_AddDoubleToTimespec(&ts, iface->tx_comp, &ts); + else if (rx_ntp_length && iface->rx_comp) + UTI_AddDoubleToTimespec(&ts, -iface->rx_comp, &ts); + + ts_delay = UTI_DiffTimespecsToDouble(&local_ts->ts, &ts); + + if (fabs(ts_delay) > MAX_TS_DELAY) { + DEBUG_LOG("Unacceptable timestamp delay %.9f", ts_delay); + return; + } + + local_ts->ts = ts; + local_ts->err = local_err; + local_ts->source = NTP_TS_HARDWARE; +} + +/* ================================================== */ +/* Extract UDP data from a layer 2 message. Supported is Ethernet + with optional VLAN tags. */ + +static int +extract_udp_data(unsigned char *msg, NTP_Remote_Address *remote_addr, int len) +{ + unsigned char *msg_start = msg; + union sockaddr_in46 addr; + + remote_addr->ip_addr.family = IPADDR_UNSPEC; + remote_addr->port = 0; + + /* Skip MACs */ + if (len < 12) + return 0; + len -= 12, msg += 12; + + /* Skip VLAN tag(s) if present */ + while (len >= 4 && msg[0] == 0x81 && msg[1] == 0x00) + len -= 4, msg += 4; + + /* Skip IPv4 or IPv6 ethertype */ + if (len < 2 || !((msg[0] == 0x08 && msg[1] == 0x00) || + (msg[0] == 0x86 && msg[1] == 0xdd))) + return 0; + len -= 2, msg += 2; + + /* Parse destination address and port from IPv4/IPv6 and UDP headers */ + if (len >= 20 && msg[0] >> 4 == 4) { + int ihl = (msg[0] & 0xf) * 4; + + if (len < ihl + 8 || msg[9] != 17) + return 0; + + memcpy(&addr.in4.sin_addr.s_addr, msg + 16, sizeof (uint32_t)); + addr.in4.sin_port = *(uint16_t *)(msg + ihl + 2); + addr.in4.sin_family = AF_INET; + len -= ihl + 8, msg += ihl + 8; +#ifdef FEAT_IPV6 + } else if (len >= 48 && msg[0] >> 4 == 6) { + int eh_len, next_header = msg[6]; + + memcpy(&addr.in6.sin6_addr.s6_addr, msg + 24, 16); + len -= 40, msg += 40; + + /* Skip IPv6 extension headers if present */ + while (next_header != 17) { + switch (next_header) { + case 44: /* Fragment Header */ + /* Process only the first fragment */ + if (ntohs(*(uint16_t *)(msg + 2)) >> 3 != 0) + return 0; + eh_len = 8; + break; + case 0: /* Hop-by-Hop Options */ + case 43: /* Routing Header */ + case 60: /* Destination Options */ + case 135: /* Mobility Header */ + eh_len = 8 * (msg[1] + 1); + break; + case 51: /* Authentication Header */ + eh_len = 4 * (msg[1] + 2); + break; + default: + return 0; + } + + if (eh_len < 8 || len < eh_len + 8) + return 0; + + next_header = msg[0]; + len -= eh_len, msg += eh_len; + } + + addr.in6.sin6_port = *(uint16_t *)(msg + 2); + addr.in6.sin6_family = AF_INET6; + len -= 8, msg += 8; +#endif + } else { + return 0; + } + + UTI_SockaddrToIPAndPort(&addr.u, &remote_addr->ip_addr, &remote_addr->port); + + /* Move the message to fix alignment of its fields */ + if (len > 0) + memmove(msg_start, msg, len); + + return len; +} + +/* ================================================== */ + +int +NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, + NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length) +{ + struct Interface *iface; + struct cmsghdr *cmsg; + int is_tx, ts_if_index, l2_length; + + is_tx = hdr->msg_flags & MSG_ERRQUEUE; + iface = NULL; + ts_if_index = local_addr->if_index; + l2_length = 0; + + for (cmsg = CMSG_FIRSTHDR(hdr); cmsg; cmsg = CMSG_NXTHDR(hdr, cmsg)) { +#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING_PKTINFO) { + struct scm_ts_pktinfo ts_pktinfo; + + memcpy(&ts_pktinfo, CMSG_DATA(cmsg), sizeof (ts_pktinfo)); + + ts_if_index = ts_pktinfo.if_index; + l2_length = ts_pktinfo.pkt_length; + + DEBUG_LOG("Received HW timestamp info if=%d length=%d", ts_if_index, l2_length); + } +#endif + + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING) { + struct scm_timestamping ts3; + + memcpy(&ts3, CMSG_DATA(cmsg), sizeof (ts3)); + + if (!UTI_IsZeroTimespec(&ts3.ts[2])) { + iface = get_interface(ts_if_index); + if (iface) { + process_hw_timestamp(iface, &ts3.ts[2], local_ts, !is_tx ? length : 0, + remote_addr->ip_addr.family, l2_length); + } else { + DEBUG_LOG("HW clock not found for interface %d", ts_if_index); + } + + /* If a HW transmit timestamp was received, resume processing + of non-error messages on this socket */ + if (is_tx) + resume_socket(local_addr->sock_fd); + } + + if (local_ts->source == NTP_TS_DAEMON && !UTI_IsZeroTimespec(&ts3.ts[0]) && + (!is_tx || UTI_IsZeroTimespec(&ts3.ts[2]))) { + LCL_CookTime(&ts3.ts[0], &local_ts->ts, &local_ts->err); + local_ts->source = NTP_TS_KERNEL; + } + } + + if ((cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR) || + (cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_RECVERR)) { + struct sock_extended_err err; + + memcpy(&err, CMSG_DATA(cmsg), sizeof (err)); + + if (err.ee_errno != ENOMSG || err.ee_info != SCM_TSTAMP_SND || + err.ee_origin != SO_EE_ORIGIN_TIMESTAMPING) { + DEBUG_LOG("Unknown extended error"); + /* Drop the message */ + return 1; + } + } + } + + /* If the kernel is slow with enabling RX timestamping, open a dummy + socket to keep the kernel RX timestamping permanently enabled */ + if (!is_tx && local_ts->source == NTP_TS_DAEMON && ts_flags) { + DEBUG_LOG("Missing kernel RX timestamp"); + if (dummy_rxts_socket == INVALID_SOCK_FD) + dummy_rxts_socket = open_dummy_socket(); + } + + /* Return the message if it's not received from the error queue */ + if (!is_tx) + return 0; + + /* The data from the error queue includes all layers up to UDP. We have to + extract the UDP data and also the destination address with port as there + currently doesn't seem to be a better way to get them both. */ + l2_length = length; + length = extract_udp_data(hdr->msg_iov[0].iov_base, remote_addr, length); + + DEBUG_LOG("Received %d (%d) bytes from error queue for %s:%d fd=%d if=%d tss=%u", + l2_length, length, UTI_IPToString(&remote_addr->ip_addr), remote_addr->port, + local_addr->sock_fd, local_addr->if_index, local_ts->source); + + /* Update assumed position of UDP data at layer 2 for next received packet */ + if (iface && length) { + if (remote_addr->ip_addr.family == IPADDR_INET4) + iface->l2_udp4_ntp_start = l2_length - length; + else if (remote_addr->ip_addr.family == IPADDR_INET6) + iface->l2_udp6_ntp_start = l2_length - length; + } + + /* Drop the message if it has no timestamp or its processing failed */ + if (local_ts->source == NTP_TS_DAEMON) { + DEBUG_LOG("Missing TX timestamp"); + return 1; + } + + if (length < NTP_NORMAL_PACKET_LENGTH) + return 1; + + NSR_ProcessTx(remote_addr, local_addr, local_ts, + (NTP_Packet *)hdr->msg_iov[0].iov_base, length); + + return 1; +} + +/* ================================================== */ + +int +NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd) +{ + struct cmsghdr *cmsg; + + if (!ts_flags) + return cmsglen; + + /* If a HW transmit timestamp is requested on a client socket, monitor + events on the socket in order to avoid processing of a fast response + without the HW timestamp of the request */ + if (ts_tx_flags & SOF_TIMESTAMPING_TX_HARDWARE && !NIO_IsServerSocket(sock_fd)) + monitored_socket = sock_fd; + + /* Check if TX timestamping is disabled on this socket */ + if (permanent_ts_options || !NIO_IsServerSocket(sock_fd)) + return cmsglen; + + /* Add control message that will enable TX timestamping for this message. + Don't use CMSG_NXTHDR as the one in glibc is buggy for creating new + control messages. */ + cmsg = (struct cmsghdr *)((char *)CMSG_FIRSTHDR(msg) + cmsglen); + memset(cmsg, 0, CMSG_SPACE(sizeof (ts_tx_flags))); + cmsglen += CMSG_SPACE(sizeof (ts_tx_flags)); + + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SO_TIMESTAMPING; + cmsg->cmsg_len = CMSG_LEN(sizeof (ts_tx_flags)); + + memcpy(CMSG_DATA(cmsg), &ts_tx_flags, sizeof (ts_tx_flags)); + + return cmsglen; +} + +/* ================================================== */ + +void +NIO_Linux_NotifySocketClosing(int sock_fd) +{ + resume_socket(sock_fd); +} |