X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ff1df423b6a8cda80cef88efa8a3162abcfd0e6e..10f1fe5fd8dfaa321621a1063d252940bb65029e:/print-ntp.c diff --git a/print-ntp.c b/print-ntp.c index 0ba62194..b4fa6129 100644 --- a/print-ntp.c +++ b/print-ntp.c @@ -18,11 +18,20 @@ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * - * Format and print ntp packets. * 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 @@ -37,6 +46,8 @@ #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). @@ -45,7 +56,7 @@ /* * Definitions for the masses */ -#define JAN_1970 2208988800U /* 1970 - 1900 in seconds */ +#define JAN_1970 INT64_T_CONSTANT(2208988800) /* 1970 - 1900 in seconds */ /* * Structure definitions for NTP fixed point values @@ -65,13 +76,13 @@ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ struct l_fixedpt { - uint32_t int_part; - uint32_t fraction; + nd_uint32_t int_part; + nd_uint32_t fraction; }; struct s_fixedpt { - uint16_t int_part; - uint16_t fraction; + nd_uint16_t int_part; + nd_uint16_t fraction; }; /* rfc2030 @@ -112,20 +123,26 @@ struct s_fixedpt { * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ -struct ntpdata { - u_char status; /* status of local clock and leap info */ - u_char stratum; /* Stratum level */ - u_char ppoll; /* poll value */ - int precision:8; +/* 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; - uint32_t refid; + nd_uint32_t refid; struct l_fixedpt ref_timestamp; struct l_fixedpt org_timestamp; struct l_fixedpt rec_timestamp; struct l_fixedpt xmt_timestamp; - uint32_t key_id; - uint8_t message_digest[16]; + nd_uint32_t key_id; + nd_uint8_t message_digest[20]; }; /* * Leap Second Codes (high order two bits) @@ -140,11 +157,14 @@ struct ntpdata { */ #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 @@ -155,7 +175,7 @@ struct ntpdata { #define MODE_CLIENT 3 /* client */ #define MODE_SERVER 4 /* server */ #define MODE_BROADCAST 5 /* broadcast */ -#define MODE_RES1 6 /* reserved */ +#define MODE_CONTROL 6 /* control message */ #define MODE_RES2 7 /* reserved */ /* @@ -169,6 +189,7 @@ struct ntpdata { 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" }, @@ -177,7 +198,7 @@ static const struct tok ntp_mode_values[] = { { MODE_CLIENT, "Client" }, { MODE_SERVER, "Server" }, { MODE_BROADCAST, "Broadcast" }, - { MODE_RES1, "Reserved" }, + { MODE_CONTROL, "Control Message" }, { MODE_RES2, "Reserved" }, { 0, NULL } }; @@ -196,67 +217,86 @@ static const struct tok ntp_stratum_values[] = { { 0, NULL } }; -/* - * Print ntp requests +/* 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 */ -void -ntp_print(netdissect_options *ndo, - register const u_char *cp, u_int length) -{ - register const struct ntpdata *bp; - int mode, version, leapind; - - bp = (const struct ntpdata *)cp; - ND_TCHECK(bp->status); - - version = (int)(bp->status & VERSIONMASK) >> 3; - ND_PRINT((ndo, "NTPv%d", version)); - - mode = bp->status & MODEMASK; - if (!ndo->ndo_vflag) { - ND_PRINT((ndo, ", %s, length %u", - tok2str(ntp_mode_values, "Unknown mode", mode), - length)); - return; - } +/* 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]] */ +}; - ND_PRINT((ndo, ", length %u\n\t%s", - length, - tok2str(ntp_mode_values, "Unknown mode", mode))); +/* + * 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; - leapind = bp->status & LEAPMASK; - ND_PRINT((ndo, ", Leap indicator: %s (%u)", - tok2str(ntp_leapind_values, "Unknown", leapind), - leapind)); + if (length < NTP_TIMEMSG_MINLEN) + goto invalid; - ND_TCHECK(bp->stratum); - ND_PRINT((ndo, ", Stratum %u (%s)", - bp->stratum, - tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum))); + 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(bp->ppoll); - ND_PRINT((ndo, ", poll %u (%us)", bp->ppoll, 1 << bp->ppoll)); + ND_TCHECK_1(bp->ppoll); + ND_PRINT(", poll %d", EXTRACT_S_1(bp->ppoll)); + p_poll(ndo, EXTRACT_U_1(bp->ppoll)); - /* Can't ND_TCHECK bp->precision bitfield so bp->distance + 0 instead */ - ND_TCHECK2(bp->root_delay, 0); - ND_PRINT((ndo, ", precision %d", bp->precision)); + ND_TCHECK_1(bp->precision); + ND_PRINT(", precision %d", EXTRACT_S_1(bp->precision)); ND_TCHECK(bp->root_delay); - ND_PRINT((ndo, "\n\tRoot Delay: ")); + ND_PRINT("\n\tRoot Delay: "); p_sfix(ndo, &bp->root_delay); ND_TCHECK(bp->root_dispersion); - ND_PRINT((ndo, ", Root dispersion: ")); + ND_PRINT(", Root dispersion: "); p_sfix(ndo, &bp->root_dispersion); - ND_TCHECK(bp->refid); - ND_PRINT((ndo, ", Reference-ID: ")); + ND_TCHECK_4(bp->refid); + ND_PRINT(", Reference-ID: "); /* Interpretation depends on stratum */ - switch (bp->stratum) { + switch (stratum) { case UNSPECIFIED: - ND_PRINT((ndo, "(unspec)")); + ND_PRINT("(unspec)"); break; case PRIM_REF: @@ -265,108 +305,271 @@ ntp_print(netdissect_options *ndo, break; case INFO_QUERY: - ND_PRINT((ndo, "%s INFO_QUERY", ipaddr_string(ndo, &(bp->refid)))); + ND_PRINT("%s INFO_QUERY", ipaddr_string(ndo, &(bp->refid))); /* this doesn't have more content */ return; case INFO_REPLY: - ND_PRINT((ndo, "%s INFO_REPLY", ipaddr_string(ndo, &(bp->refid)))); + ND_PRINT("%s INFO_REPLY", ipaddr_string(ndo, &(bp->refid))); /* this is too complex to be worth printing */ return; default: - ND_PRINT((ndo, "%s", ipaddr_string(ndo, &(bp->refid)))); + /* 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(bp->ref_timestamp); - ND_PRINT((ndo, "\n\t Reference Timestamp: ")); + ND_PRINT("\n\t Reference Timestamp: "); p_ntp_time(ndo, &(bp->ref_timestamp)); ND_TCHECK(bp->org_timestamp); - ND_PRINT((ndo, "\n\t Originator Timestamp: ")); + ND_PRINT("\n\t Originator Timestamp: "); p_ntp_time(ndo, &(bp->org_timestamp)); ND_TCHECK(bp->rec_timestamp); - ND_PRINT((ndo, "\n\t Receive Timestamp: ")); + ND_PRINT("\n\t Receive Timestamp: "); p_ntp_time(ndo, &(bp->rec_timestamp)); ND_TCHECK(bp->xmt_timestamp); - ND_PRINT((ndo, "\n\t Transmit Timestamp: ")); + ND_PRINT("\n\t Transmit Timestamp: "); p_ntp_time(ndo, &(bp->xmt_timestamp)); - ND_PRINT((ndo, "\n\t Originator - Receive Timestamp: ")); + ND_PRINT("\n\t Originator - Receive Timestamp: "); p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->rec_timestamp)); - ND_PRINT((ndo, "\n\t Originator - Transmit Timestamp: ")); + ND_PRINT("\n\t Originator - Transmit Timestamp: "); p_ntp_delta(ndo, &(bp->org_timestamp), &(bp->xmt_timestamp)); - if ( (sizeof(struct ntpdata) - length) == 16) { /* Optional: key-id */ - ND_TCHECK(bp->key_id); - ND_PRINT((ndo, "\n\tKey id: %u", bp->key_id)); - } else if ( (sizeof(struct ntpdata) - length) == 0) { /* Optional: key-id + authentication */ - ND_TCHECK(bp->key_id); - ND_PRINT((ndo, "\n\tKey id: %u", bp->key_id)); - ND_TCHECK2(bp->message_digest, sizeof (bp->message_digest)); - ND_PRINT((ndo, "\n\tAuthentication: %08x%08x%08x%08x", - EXTRACT_32BITS(bp->message_digest), - EXTRACT_32BITS(bp->message_digest + 4), - EXTRACT_32BITS(bp->message_digest + 8), - EXTRACT_32BITS(bp->message_digest + 12))); - } + /* 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((ndo, " [|ntp]")); + ND_PRINT(" %s", tstr); } static void p_sfix(netdissect_options *ndo, - register const struct s_fixedpt *sfp) + const struct s_fixedpt *sfp) { - register int i; - register int f; - register double ff; + int i; + int f; + double ff; - i = EXTRACT_16BITS(&sfp->int_part); - f = EXTRACT_16BITS(&sfp->fraction); + 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((ndo, "%d.%06d", i, f)); + ND_PRINT("%d.%06d", i, f); } #define FMAXINT (4294967296.0) /* floating point rep. of MAXINT */ static void p_ntp_time(netdissect_options *ndo, - register const struct l_fixedpt *lfp) + const struct l_fixedpt *lfp) { - register int32_t i; - register uint32_t uf; - register uint32_t f; - register double ff; + uint32_t i; + uint32_t uf; + uint32_t f; + double ff; - i = EXTRACT_32BITS(&lfp->int_part); - uf = EXTRACT_32BITS(&lfp->fraction); + 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((ndo, "%u.%09d", i, f)); + ND_PRINT("%u.%09d", i, f); #ifdef HAVE_STRFTIME /* - * print the time in human-readable format. + * print the UTC time in human-readable format. */ if (i) { - time_t seconds = i - JAN_1970; + int64_t seconds_64bit = (int64_t)i - JAN_1970; + time_t seconds; struct tm *tm; char time_buf[128]; - tm = localtime(&seconds); - strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm); - ND_PRINT((ndo, " (%s)", time_buf)); + 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 } @@ -374,20 +577,20 @@ p_ntp_time(netdissect_options *ndo, /* Prints time difference between *lfp and *olfp */ static void p_ntp_delta(netdissect_options *ndo, - register const struct l_fixedpt *olfp, - register const struct l_fixedpt *lfp) + const struct l_fixedpt *olfp, + const struct l_fixedpt *lfp) { - register int32_t i; - register uint32_t u, uf; - register uint32_t ou, ouf; - register uint32_t f; - register double ff; + int32_t i; + uint32_t u, uf; + uint32_t ou, ouf; + uint32_t f; + double ff; int signbit; - u = EXTRACT_32BITS(&lfp->int_part); - ou = EXTRACT_32BITS(&olfp->int_part); - uf = EXTRACT_32BITS(&lfp->fraction); - ouf = EXTRACT_32BITS(&olfp->fraction); + 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; @@ -421,6 +624,20 @@ p_ntp_delta(netdissect_options *ndo, 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((ndo, "%s%d.%09d", signbit ? "-" : "+", i, f)); + 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); }