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+/*
+ * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code distributions
+ * retain the above copyright notice and this paragraph in its entirety, (2)
+ * distributions including binary code include the above copyright notice and
+ * this paragraph in its entirety in the documentation or other materials
+ * provided with the distribution, and (3) all advertising materials mentioning
+ * features or use of this software display the following acknowledgement:
+ * ``This product includes software developed by the University of California,
+ * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
+ * the University nor the names of its contributors may be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * By Jeffrey Mogul/DECWRL
+ * loosely based on print-bootp.c
+ */
+
+/* \summary: Network Time Protocol (NTP) printer */
+
+/*
+ * specification:
+ *
+ * RFC 1119 - NTPv2
+ * RFC 1305 - NTPv3
+ * RFC 5905 - NTPv4
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include <time.h>
+
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+#include "ntp.h"
+
+/*
+ * Based on ntp.h from the U of MD implementation
+ * This file is based on Version 2 of the NTP spec (RFC1119).
+ */
+
+/* rfc2030
+ * 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |LI | VN |Mode | Stratum | Poll | Precision |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Root Delay |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Root Dispersion |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Reference Identifier |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * | Reference Timestamp (64) |
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * | Originate Timestamp (64) |
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * | Receive Timestamp (64) |
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * | Transmit Timestamp (64) |
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Key Identifier (optional) (32) |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * | |
+ * | Message Digest (optional) (128) |
+ * | |
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+/* Length of the NTP data message with the mandatory fields ("the header")
+ * and without any optional fields (extension, Key Identifier,
+ * Message Digest).
+ */
+#define NTP_TIMEMSG_MINLEN 48U
+
+struct ntp_time_data {
+ nd_uint8_t status; /* status of local clock and leap info */
+ nd_uint8_t stratum; /* Stratum level */
+ nd_int8_t ppoll; /* poll value */
+ nd_int8_t precision;
+ struct s_fixedpt root_delay;
+ struct s_fixedpt root_dispersion;
+ nd_uint32_t refid;
+ struct l_fixedpt ref_timestamp;
+ struct l_fixedpt org_timestamp;
+ struct l_fixedpt rec_timestamp;
+ struct l_fixedpt xmt_timestamp;
+ nd_uint32_t key_id;
+ nd_uint8_t message_digest[20];
+};
+/*
+ * Leap Second Codes (high order two bits)
+ */
+#define NO_WARNING 0x00 /* no warning */
+#define PLUS_SEC 0x40 /* add a second (61 seconds) */
+#define MINUS_SEC 0x80 /* minus a second (59 seconds) */
+#define ALARM 0xc0 /* alarm condition (clock unsynchronized) */
+
+/*
+ * Clock Status Bits that Encode Version
+ */
+#define NTPVERSION_1 0x08
+#define VERSIONMASK 0x38
+#define VERSIONSHIFT 3
+#define LEAPMASK 0xc0
+#define LEAPSHIFT 6
+#ifdef MODEMASK
+#undef MODEMASK /* Solaris sucks */
+#endif
+#define MODEMASK 0x07
+#define MODESHIFT 0
+
+/*
+ * Code values
+ */
+#define MODE_UNSPEC 0 /* unspecified */
+#define MODE_SYM_ACT 1 /* symmetric active */
+#define MODE_SYM_PAS 2 /* symmetric passive */
+#define MODE_CLIENT 3 /* client */
+#define MODE_SERVER 4 /* server */
+#define MODE_BROADCAST 5 /* broadcast */
+#define MODE_CONTROL 6 /* control message */
+#define MODE_RES2 7 /* reserved */
+
+/*
+ * Stratum Definitions
+ */
+#define UNSPECIFIED 0
+#define PRIM_REF 1 /* radio clock */
+#define INFO_QUERY 62 /* **** THIS implementation dependent **** */
+#define INFO_REPLY 63 /* **** THIS implementation dependent **** */
+
+static void p_sfix(netdissect_options *ndo, const struct s_fixedpt *);
+static void p_ntp_delta(netdissect_options *, const struct l_fixedpt *, const struct l_fixedpt *);
+static void p_poll(netdissect_options *, const int);
+
+static const struct tok ntp_mode_values[] = {
+ { MODE_UNSPEC, "unspecified" },
+ { MODE_SYM_ACT, "symmetric active" },
+ { MODE_SYM_PAS, "symmetric passive" },
+ { MODE_CLIENT, "Client" },
+ { MODE_SERVER, "Server" },
+ { MODE_BROADCAST, "Broadcast" },
+ { MODE_CONTROL, "Control Message" },
+ { MODE_RES2, "Reserved" },
+ { 0, NULL }
+};
+
+static const struct tok ntp_leapind_values[] = {
+ { NO_WARNING, "" },
+ { PLUS_SEC, "+1s" },
+ { MINUS_SEC, "-1s" },
+ { ALARM, "clock unsynchronized" },
+ { 0, NULL }
+};
+
+static const struct tok ntp_stratum_values[] = {
+ { UNSPECIFIED, "unspecified" },
+ { PRIM_REF, "primary reference" },
+ { 0, NULL }
+};
+
+/* draft-ietf-ntp-mode-6-cmds-02
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |LI | VN |Mode |R|E|M| OpCode | Sequence Number |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Status | Association ID |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Offset | Count |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * / Data (up to 468 bytes) /
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Padding (optional) |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * / Authenticator (optional, 96 bytes) /
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Figure 1: NTP Control Message Header
+ */
+
+/* Length of the NTP control message with the mandatory fields ("the header")
+ * and without any optional fields (Data, Padding, Authenticator).
+ */
+#define NTP_CTRLMSG_MINLEN 12U
+
+struct ntp_control_data {
+ nd_uint8_t magic; /* LI, VN, Mode */
+ nd_uint8_t control; /* R, E, M, OpCode */
+ nd_uint16_t sequence; /* Sequence Number */
+ nd_uint16_t status; /* Status */
+ nd_uint16_t assoc; /* Association ID */
+ nd_uint16_t offset; /* Offset */
+ nd_uint16_t count; /* Count */
+ nd_uint8_t data[564]; /* Data, [Padding, [Authenticator]] */
+};
+
+/*
+ * Print NTP time requests and responses
+ */
+static void
+ntp_time_print(netdissect_options *ndo,
+ const struct ntp_time_data *bp, u_int length)
+{
+ uint8_t stratum;
+
+ if (length < NTP_TIMEMSG_MINLEN)
+ goto invalid;
+
+ stratum = GET_U_1(bp->stratum);
+ ND_PRINT(", Stratum %u (%s)",
+ stratum,
+ tok2str(ntp_stratum_values, (stratum >=2 && stratum<=15) ? "secondary reference" : "reserved", stratum));
+
+ ND_PRINT(", poll %d", GET_S_1(bp->ppoll));
+ p_poll(ndo, GET_S_1(bp->ppoll));
+
+ ND_PRINT(", precision %d", GET_S_1(bp->precision));
+
+ ND_TCHECK_SIZE(&bp->root_delay);
+ ND_PRINT("\n\tRoot Delay: ");
+ p_sfix(ndo, &bp->root_delay);
+
+ ND_TCHECK_SIZE(&bp->root_dispersion);
+ ND_PRINT(", Root dispersion: ");
+ p_sfix(ndo, &bp->root_dispersion);
+
+ ND_TCHECK_4(bp->refid);
+ ND_PRINT(", Reference-ID: ");
+ /* Interpretation depends on stratum */
+ switch (stratum) {
+
+ case UNSPECIFIED:
+ ND_PRINT("(unspec)");
+ break;
+
+ case PRIM_REF:
+ if (nd_printn(ndo, (const u_char *)&(bp->refid), 4, ndo->ndo_snapend))
+ goto trunc;
+ break;
+
+ case INFO_QUERY:
+ ND_PRINT("%s INFO_QUERY", GET_IPADDR_STRING(bp->refid));
+ /* this doesn't have more content */
+ return;
+
+ case INFO_REPLY:
+ ND_PRINT("%s INFO_REPLY", GET_IPADDR_STRING(bp->refid));
+ /* this is too complex to be worth printing */
+ return;
+
+ default:
+ /* In NTPv4 (RFC 5905) refid is an IPv4 address or first 32 bits of
+ MD5 sum of IPv6 address */
+ ND_PRINT("0x%08x", GET_BE_U_4(bp->refid));
+ break;
+ }
+
+ ND_TCHECK_SIZE(&bp->ref_timestamp);
+ ND_PRINT("\n\t Reference Timestamp: ");
+ p_ntp_time(ndo, &(bp->ref_timestamp));
+
+ ND_TCHECK_SIZE(&bp->org_timestamp);
+ ND_PRINT("\n\t Originator Timestamp: ");
+ p_ntp_time(ndo, &(bp->org_timestamp));
+
+ ND_TCHECK_SIZE(&bp->rec_timestamp);
+ ND_PRINT("\n\t Receive Timestamp: ");
+ p_ntp_time(ndo, &(bp->rec_timestamp));
+
+ ND_TCHECK_SIZE(&bp->xmt_timestamp);
+ ND_PRINT("\n\t Transmit Timestamp: ");
+ p_ntp_time(ndo, &(bp->xmt_timestamp));
+
+ ND_PRINT("\n\t Originator - Receive Timestamp: ");
+ p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->rec_timestamp));
+
+ ND_PRINT("\n\t Originator - Transmit Timestamp: ");
+ p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->xmt_timestamp));
+
+ /* FIXME: this code is not aware of any extension fields */
+ if (length == NTP_TIMEMSG_MINLEN + 4) { /* Optional: key-id (crypto-NAK) */
+ ND_PRINT("\n\tKey id: %u", GET_BE_U_4(bp->key_id));
+ } else if (length == NTP_TIMEMSG_MINLEN + 4 + 16) { /* Optional: key-id + 128-bit digest */
+ ND_PRINT("\n\tKey id: %u", GET_BE_U_4(bp->key_id));
+ ND_TCHECK_LEN(bp->message_digest, 16);
+ ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x",
+ GET_BE_U_4(bp->message_digest),
+ GET_BE_U_4(bp->message_digest + 4),
+ GET_BE_U_4(bp->message_digest + 8),
+ GET_BE_U_4(bp->message_digest + 12));
+ } else if (length == NTP_TIMEMSG_MINLEN + 4 + 20) { /* Optional: key-id + 160-bit digest */
+ ND_PRINT("\n\tKey id: %u", GET_BE_U_4(bp->key_id));
+ ND_TCHECK_LEN(bp->message_digest, 20);
+ ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x%08x",
+ GET_BE_U_4(bp->message_digest),
+ GET_BE_U_4(bp->message_digest + 4),
+ GET_BE_U_4(bp->message_digest + 8),
+ GET_BE_U_4(bp->message_digest + 12),
+ GET_BE_U_4(bp->message_digest + 16));
+ } else if (length > NTP_TIMEMSG_MINLEN) {
+ ND_PRINT("\n\t(%u more bytes after the header)", length - NTP_TIMEMSG_MINLEN);
+ }
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(bp, length);
+ return;
+
+trunc:
+ nd_print_trunc(ndo);
+}
+
+/*
+ * Print NTP control message requests and responses
+ */
+static void
+ntp_control_print(netdissect_options *ndo,
+ const struct ntp_control_data *cd, u_int length)
+{
+ uint8_t control, R, E, M, opcode;
+ uint16_t sequence, status, assoc, offset, count;
+
+ if (length < NTP_CTRLMSG_MINLEN)
+ goto invalid;
+
+ control = GET_U_1(cd->control);
+ R = (control & 0x80) != 0;
+ E = (control & 0x40) != 0;
+ M = (control & 0x20) != 0;
+ opcode = control & 0x1f;
+ ND_PRINT(", %s, %s, %s, OpCode=%u\n",
+ R ? "Response" : "Request", E ? "Error" : "OK",
+ M ? "More" : "Last", opcode);
+
+ sequence = GET_BE_U_2(cd->sequence);
+ ND_PRINT("\tSequence=%hu", sequence);
+
+ status = GET_BE_U_2(cd->status);
+ ND_PRINT(", Status=%#hx", status);
+
+ assoc = GET_BE_U_2(cd->assoc);
+ ND_PRINT(", Assoc.=%hu", assoc);
+
+ offset = GET_BE_U_2(cd->offset);
+ ND_PRINT(", Offset=%hu", offset);
+
+ count = GET_BE_U_2(cd->count);
+ ND_PRINT(", Count=%hu", count);
+
+ if (NTP_CTRLMSG_MINLEN + count > length)
+ goto invalid;
+ if (count != 0) {
+ ND_TCHECK_LEN(cd->data, count);
+ ND_PRINT("\n\tTO-BE-DONE: data not interpreted");
+ }
+ return;
+
+invalid:
+ nd_print_invalid(ndo);
+ ND_TCHECK_LEN(cd, length);
+ return;
+
+trunc:
+ nd_print_trunc(ndo);
+}
+
+union ntpdata {
+ struct ntp_time_data td;
+ struct ntp_control_data cd;
+};
+
+/*
+ * Print NTP requests, handling the common VN, LI, and Mode
+ */
+void
+ntp_print(netdissect_options *ndo,
+ const u_char *cp, u_int length)
+{
+ const union ntpdata *bp = (const union ntpdata *)cp;
+ u_int mode, version, leapind;
+ uint8_t status;
+
+ ndo->ndo_protocol = "ntp";
+ status = GET_U_1(bp->td.status);
+
+ version = (status & VERSIONMASK) >> VERSIONSHIFT;
+ ND_PRINT("NTPv%u", version);
+
+ mode = (status & MODEMASK) >> MODESHIFT;
+ if (!ndo->ndo_vflag) {
+ ND_PRINT(", %s, length %u",
+ tok2str(ntp_mode_values, "Unknown mode", mode),
+ length);
+ return;
+ }
+
+ ND_PRINT(", %s, length %u\n",
+ tok2str(ntp_mode_values, "Unknown mode", mode), length);
+
+ /* leapind = (status & LEAPMASK) >> LEAPSHIFT; */
+ leapind = (status & LEAPMASK);
+ ND_PRINT("\tLeap indicator: %s (%u)",
+ tok2str(ntp_leapind_values, "Unknown", leapind),
+ leapind);
+
+ switch (mode) {
+
+ case MODE_UNSPEC:
+ case MODE_SYM_ACT:
+ case MODE_SYM_PAS:
+ case MODE_CLIENT:
+ case MODE_SERVER:
+ case MODE_BROADCAST:
+ ntp_time_print(ndo, &bp->td, length);
+ break;
+
+ case MODE_CONTROL:
+ ntp_control_print(ndo, &bp->cd, length);
+ break;
+
+ default:
+ break; /* XXX: not implemented! */
+ }
+}
+
+static void
+p_sfix(netdissect_options *ndo,
+ const struct s_fixedpt *sfp)
+{
+ int i;
+ int f;
+ double ff;
+
+ i = GET_BE_U_2(sfp->int_part);
+ f = GET_BE_U_2(sfp->fraction);
+ ff = f / 65536.0; /* shift radix point by 16 bits */
+ f = (int)(ff * 1000000.0); /* Treat fraction as parts per million */
+ ND_PRINT("%d.%06d", i, f);
+}
+
+/* Prints time difference between *lfp and *olfp */
+static void
+p_ntp_delta(netdissect_options *ndo,
+ const struct l_fixedpt *olfp,
+ const struct l_fixedpt *lfp)
+{
+ uint32_t u, uf;
+ uint32_t ou, ouf;
+ uint32_t i;
+ uint32_t f;
+ double ff;
+ int signbit;
+
+ u = GET_BE_U_4(lfp->int_part);
+ ou = GET_BE_U_4(olfp->int_part);
+ uf = GET_BE_U_4(lfp->fraction);
+ ouf = GET_BE_U_4(olfp->fraction);
+ if (ou == 0 && ouf == 0) {
+ p_ntp_time(ndo, lfp);
+ return;
+ }
+
+ if (u > ou) { /* new is definitely greater than old */
+ signbit = 0;
+ i = u - ou;
+ f = uf - ouf;
+ if (ouf > uf) /* must borrow from high-order bits */
+ i -= 1;
+ } else if (u < ou) { /* new is definitely less than old */
+ signbit = 1;
+ i = ou - u;
+ f = ouf - uf;
+ if (uf > ouf) /* must borrow from the high-order bits */
+ i -= 1;
+ } else { /* int_part is zero */
+ i = 0;
+ if (uf > ouf) {
+ signbit = 0;
+ f = uf - ouf;
+ } else {
+ signbit = 1;
+ f = ouf - uf;
+ }
+ }
+
+ ff = f;
+ if (ff < 0.0) /* some compilers are buggy */
+ ff += FMAXINT;
+ ff = ff / FMAXINT; /* shift radix point by 32 bits */
+ f = (uint32_t)(ff * 1000000000.0); /* treat fraction as parts per billion */
+ ND_PRINT("%s%u.%09u", signbit ? "-" : "+", i, f);
+}
+
+/* Prints polling interval in log2 as seconds or fraction of second */
+static void
+p_poll(netdissect_options *ndo,
+ const int poll_interval)
+{
+ if (poll_interval <= -32 || poll_interval >= 32)
+ return;
+
+ if (poll_interval >= 0)
+ ND_PRINT(" (%us)", 1U << poll_interval);
+ else
+ ND_PRINT(" (1/%us)", 1U << -poll_interval);
+}
+