/* * 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 #endif #include "netdissect-stdinc.h" #ifdef HAVE_STRFTIME #include #endif #include "netdissect.h" #include "addrtoname.h" #include "extract.h" static const char tstr[] = " [|ntp]"; /* * Based on ntp.h from the U of MD implementation * This file is based on Version 2 of the NTP spec (RFC1119). */ /* * Definitions for the masses */ #define JAN_1970 INT64_T_CONSTANT(2208988800) /* 1970 - 1900 in seconds */ /* * Structure definitions for NTP fixed point values * * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Integer Part | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Fraction Part | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * 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 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Integer Part | Fraction Part | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct l_fixedpt { nd_uint32_t int_part; nd_uint32_t fraction; }; struct s_fixedpt { nd_uint16_t int_part; nd_uint16_t fraction; }; /* 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_time(netdissect_options *, const struct l_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; ND_TCHECK_1(bp->stratum); stratum = EXTRACT_U_1(bp->stratum); ND_PRINT(", Stratum %u (%s)", stratum, tok2str(ntp_stratum_values, (stratum >=2 && stratum<=15) ? "secondary reference" : "reserved", stratum)); ND_TCHECK_1(bp->ppoll); ND_PRINT(", poll %d", EXTRACT_S_1(bp->ppoll)); p_poll(ndo, EXTRACT_U_1(bp->ppoll)); ND_TCHECK_1(bp->precision); ND_PRINT(", precision %d", EXTRACT_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 (fn_printn(ndo, (const u_char *)&(bp->refid), 4, ndo->ndo_snapend)) goto trunc; break; case INFO_QUERY: ND_PRINT("%s INFO_QUERY", ipaddr_string(ndo, bp->refid)); /* this doesn't have more content */ return; case INFO_REPLY: ND_PRINT("%s INFO_REPLY", ipaddr_string(ndo, 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", EXTRACT_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_TCHECK_4(bp->key_id); ND_PRINT("\n\tKey id: %u", EXTRACT_BE_U_4(bp->key_id)); } else if (length == NTP_TIMEMSG_MINLEN + 4 + 16) { /* Optional: key-id + 128-bit digest */ ND_TCHECK_4(bp->key_id); ND_PRINT("\n\tKey id: %u", EXTRACT_BE_U_4(bp->key_id)); ND_TCHECK_LEN(bp->message_digest, 16); ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x", EXTRACT_BE_U_4(bp->message_digest), EXTRACT_BE_U_4(bp->message_digest + 4), EXTRACT_BE_U_4(bp->message_digest + 8), EXTRACT_BE_U_4(bp->message_digest + 12)); } else if (length == NTP_TIMEMSG_MINLEN + 4 + 20) { /* Optional: key-id + 160-bit digest */ ND_TCHECK_4(bp->key_id); ND_PRINT("\n\tKey id: %u", EXTRACT_BE_U_4(bp->key_id)); ND_TCHECK_LEN(bp->message_digest, 20); ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x%08x", EXTRACT_BE_U_4(bp->message_digest), EXTRACT_BE_U_4(bp->message_digest + 4), EXTRACT_BE_U_4(bp->message_digest + 8), EXTRACT_BE_U_4(bp->message_digest + 12), EXTRACT_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(" %s", istr); ND_TCHECK_LEN(bp, length); return; trunc: ND_PRINT(" %s", tstr); } /* * 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; ND_TCHECK_1(cd->control); control = EXTRACT_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); ND_TCHECK_2(cd->sequence); sequence = EXTRACT_BE_U_2(cd->sequence); ND_PRINT("\tSequence=%hu", sequence); ND_TCHECK_2(cd->status); status = EXTRACT_BE_U_2(cd->status); ND_PRINT(", Status=%#hx", status); ND_TCHECK_2(cd->assoc); assoc = EXTRACT_BE_U_2(cd->assoc); ND_PRINT(", Assoc.=%hu", assoc); ND_TCHECK_2(cd->offset); offset = EXTRACT_BE_U_2(cd->offset); ND_PRINT(", Offset=%hu", offset); ND_TCHECK_2(cd->count); count = EXTRACT_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(" %s", istr); ND_TCHECK_LEN(cd, length); return; trunc: ND_PRINT(" %s", tstr); } 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; ND_TCHECK_1(bp->td.status); status = EXTRACT_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! */ } return; trunc: ND_PRINT(" %s", tstr); } static void p_sfix(netdissect_options *ndo, const struct s_fixedpt *sfp) { int i; int f; double ff; i = EXTRACT_BE_U_2(sfp->int_part); f = EXTRACT_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); } #define FMAXINT (4294967296.0) /* floating point rep. of MAXINT */ static void p_ntp_time(netdissect_options *ndo, const struct l_fixedpt *lfp) { uint32_t i; uint32_t uf; uint32_t f; double ff; i = EXTRACT_BE_U_4(lfp->int_part); uf = EXTRACT_BE_U_4(lfp->fraction); ff = uf; 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("%u.%09d", i, f); #ifdef HAVE_STRFTIME /* * print the UTC time in human-readable format. */ if (i) { int64_t seconds_64bit = (int64_t)i - JAN_1970; time_t seconds; struct tm *tm; char time_buf[128]; seconds = (time_t)seconds_64bit; if (seconds != seconds_64bit) { /* * It doesn't fit into a time_t, so we can't hand it * to gmtime. */ ND_PRINT(" (unrepresentable)"); } else { tm = gmtime(&seconds); if (tm == NULL) { /* * gmtime() can't handle it. * (Yes, that might happen with some version of * Microsoft's C library.) */ ND_PRINT(" (unrepresentable)"); } else { /* use ISO 8601 (RFC3339) format */ strftime(time_buf, sizeof (time_buf), "%Y-%m-%dT%H:%M:%S", tm); ND_PRINT(" (%s)", time_buf); } } } #endif } /* 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) { int32_t i; uint32_t u, uf; uint32_t ou, ouf; uint32_t f; double ff; int signbit; u = EXTRACT_BE_U_4(lfp->int_part); ou = EXTRACT_BE_U_4(olfp->int_part); uf = EXTRACT_BE_U_4(lfp->fraction); ouf = EXTRACT_BE_U_4(olfp->fraction); if (ou == 0 && ouf == 0) { p_ntp_time(ndo, lfp); return; } i = u - ou; if (i > 0) { /* new is definitely greater than old */ signbit = 0; f = uf - ouf; if (ouf > uf) /* must borrow from high-order bits */ i -= 1; } else if (i < 0) { /* new is definitely less than old */ signbit = 1; f = ouf - uf; if (uf > ouf) /* must carry into the high-order bits */ i += 1; i = -i; } else { /* int_part is zero */ 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%d.%09d", 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); }