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Diffstat (limited to '')
| -rw-r--r-- | print-ntp.c | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/print-ntp.c b/print-ntp.c new file mode 100644 index 0000000..537975c --- /dev/null +++ b/print-ntp.c @@ -0,0 +1,536 @@ +/* + * 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); +} + |