Fix incompatible pointer types with time functions calls on Windows

[tcpdump] / print-ntp.c

diff --git a/print-ntp.c b/print-ntp.c
index b37dcf3a7a1a46b5c86686fb7a4d2275f445f8a1..d1c0433cff5e73d555c3329eb238ce5b69e0ddaa 100644 (file)
--- a/print-ntp.c
+++ b/print-ntp.c
@@ -18,70 +18,37 @@
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
  * 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
  */
 
  *     By Jeffrey Mogul/DECWRL
  *     loosely based on print-bootp.c
  */
 

-#ifndef lint
-static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-ntp.c,v 1.43 2007-11-30 13:45:10 hannes Exp $ (LBL)";
-#endif
+/* \summary: Network Time Protocol (NTP) printer */

 
 

-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+/*
+ * specification:
+ *
+ * RFC 1119 - NTPv2
+ * RFC 1305 - NTPv3
+ * RFC 5905 - NTPv4
+ */

 
 

-#include <tcpdump-stdinc.h>
+#include <config.h>

 
 

-#include <stdio.h>
-#include <string.h>
-#ifdef HAVE_STRFTIME
-#include <time.h>
-#endif
+#include "netdissect-stdinc.h"

 
 

-#include "interface.h"
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"

 #include "addrtoname.h"
 #include "extract.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).
  */
 
 /*
  * 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        2208988800U     /* 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 {
-       u_int32_t int_part;
-       u_int32_t fraction;
-};
-
-struct s_fixedpt {
-       u_int16_t int_part;
-       u_int16_t fraction;
-};
-
-/* rfc2030
+/* RFC 5905 updated by RFC 7822

  *                      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
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *                      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
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


@@ -109,31 +76,41 @@ struct s_fixedpt {
  * |                    Transmit Timestamp (64)                    |
  * |                                                               |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  * |                    Transmit Timestamp (64)                    |
  * |                                                               |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

- * |                 Key Identifier (optional) (32)                |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * |                                                               |
- * |                                                               |
- * |                 Message Digest (optional) (128)               |

  * |                                                               |
  * |                                                               |

+ * .                                                               .
+ * .                 Optional Extensions (variable)                .
+ * .                                                               .

  * |                                                               |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  */
 
  * |                                                               |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  */
 

-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;
        struct s_fixedpt root_delay;
        struct s_fixedpt root_dispersion;

-       u_int32_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;
        struct l_fixedpt ref_timestamp;
        struct l_fixedpt org_timestamp;
        struct l_fixedpt rec_timestamp;
        struct l_fixedpt xmt_timestamp;

-        u_int32_t key_id;
-        u_int8_t  message_digest[16];
+       /* extension fields and/or MAC follow */
+};
+
+struct ntp_extension_field {
+       nd_uint16_t     type;
+       nd_uint16_t     length;
+       /* body follows */

 };
 };

+

 /*
  *     Leap Second Codes (high order two bits)
  */
 /*
  *     Leap Second Codes (high order two bits)
  */


@@ -147,11 +124,14 @@ struct ntpdata {
  */
 #define        NTPVERSION_1    0x08
 #define        VERSIONMASK     0x38
  */
 #define        NTPVERSION_1    0x08
 #define        VERSIONMASK     0x38

+#define        VERSIONSHIFT    3

 #define LEAPMASK       0xc0
 #define LEAPMASK       0xc0

+#define LEAPSHIFT      6

 #ifdef MODEMASK
 #undef MODEMASK                                        /* Solaris sucks */
 #endif
 #define        MODEMASK        0x07
 #ifdef MODEMASK
 #undef MODEMASK                                        /* Solaris sucks */
 #endif
 #define        MODEMASK        0x07

+#define        MODESHIFT       0

 
 /*
  *     Code values
 
 /*
  *     Code values


@@ -162,7 +142,7 @@ struct ntpdata {
 #define        MODE_CLIENT     3       /* client */
 #define        MODE_SERVER     4       /* server */
 #define        MODE_BROADCAST  5       /* broadcast */
 #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 */
 
 /*
 #define        MODE_RES2       7       /* reserved */
 
 /*


@@ -173,9 +153,10 @@ struct ntpdata {
 #define        INFO_QUERY      62      /* **** THIS implementation dependent **** */
 #define        INFO_REPLY      63      /* **** THIS implementation dependent **** */
 
 #define        INFO_QUERY      62      /* **** THIS implementation dependent **** */
 #define        INFO_REPLY      63      /* **** THIS implementation dependent **** */
 

-static void p_sfix(const struct s_fixedpt *);
-static void p_ntp_time(const struct l_fixedpt *);
-static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *);
+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 u_int p_ext_fields(netdissect_options *, const u_char *, u_int length);

 
 static const struct tok ntp_mode_values[] = {
     { MODE_UNSPEC,    "unspecified" },
 
 static const struct tok ntp_mode_values[] = {
     { MODE_UNSPEC,    "unspecified" },


@@ -184,7 +165,7 @@ static const struct tok ntp_mode_values[] = {
     { MODE_CLIENT,    "Client" },
     { MODE_SERVER,    "Server" },
     { MODE_BROADCAST, "Broadcast" },
     { MODE_CLIENT,    "Client" },
     { MODE_SERVER,    "Server" },
     { MODE_BROADCAST, "Broadcast" },

-    { MODE_RES1,      "Reserved" },
+    { MODE_CONTROL,   "Control Message" },

     { MODE_RES2,      "Reserved" },
     { 0, NULL }
 };
     { MODE_RES2,      "Reserved" },
     { 0, NULL }
 };


@@ -199,217 +180,332 @@ static const struct tok ntp_leapind_values[] = {
 
 static const struct tok ntp_stratum_values[] = {
        { UNSPECIFIED,  "unspecified" },
 
 static const struct tok ntp_stratum_values[] = {
        { UNSPECIFIED,  "unspecified" },

-       { PRIM_REF,     "primary reference" },
+       { PRIM_REF,     "primary reference" },
+       { 0, NULL }
+};
+
+static const struct tok ntp_ef_types[] = {
+       { 0x0104,       "Unique Identifier" },
+       { 0x0204,       "NTS Cookie" },
+       { 0x0304,       "NTS Cookie Placeholder" },
+       { 0x0404,       "NTS Authenticator and Encrypted Extension Fields" },
+       { 0x2005,       "Checksum Complement" },

        { 0, NULL }
 };
 
        { 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 requests
+ * Print NTP time requests and responses

  */
  */

-void
-ntp_print(register const u_char *cp, u_int length)
+static void
+ntp_time_print(netdissect_options *ndo,
+              const struct ntp_time_data *bp, u_int length, u_int version)

 {
 {

-       register const struct ntpdata *bp;
-       int mode, version, leapind;
-
-       bp = (struct ntpdata *)cp;
-
-       TCHECK(bp->status);
-
-       version = (int)(bp->status & VERSIONMASK) >> 3;
-       printf("NTPv%d", version);
-
-       mode = bp->status & MODEMASK;
-        if (!vflag) {
-            printf (", %s, length %u",
-                    tok2str(ntp_mode_values, "Unknown mode", mode),
-                    length);
-            return;
-        }
-        
-        printf (", length %u\n\t%s",
-                length,
-                tok2str(ntp_mode_values, "Unknown mode", mode));        
-
-       leapind = bp->status & LEAPMASK;
-        printf (", Leap indicator: %s (%u)",
-                tok2str(ntp_leapind_values, "Unknown", leapind),
-                leapind);
-
-       TCHECK(bp->stratum);
-       printf(", Stratum %u (%s)",     
-               bp->stratum,
-               tok2str(ntp_stratum_values, (bp->stratum >=2 && bp->stratum<=15) ? "secondary reference" : "reserved", bp->stratum));
-
-       TCHECK(bp->ppoll);
-       printf(", poll %u (%us)", bp->ppoll, 1 << bp->ppoll);
-
-       /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
-       TCHECK2(bp->root_delay, 0);
-       printf(", precision %d", bp->precision);
-
-       TCHECK(bp->root_delay);
-       fputs("\n\tRoot Delay: ", stdout);
-       p_sfix(&bp->root_delay);
-
-       TCHECK(bp->root_dispersion);
-       fputs(", Root dispersion: ", stdout);
-       p_sfix(&bp->root_dispersion);
-
-       TCHECK(bp->refid);
-       fputs(", Reference-ID: ", stdout);
+       const u_char *mac;
+       uint8_t stratum;
+       u_int efs_len;
+
+       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_PRINT("\n\tRoot Delay: ");
+       p_sfix(ndo, &bp->root_delay);
+
+       ND_PRINT(", Root dispersion: ");
+       p_sfix(ndo, &bp->root_dispersion);
+
+       ND_PRINT(", Reference-ID: ");

        /* Interpretation depends on stratum */
        /* Interpretation depends on stratum */

-       switch (bp->stratum) {
+       switch (stratum) {

 
        case UNSPECIFIED:
 
        case UNSPECIFIED:

-               printf("(unspec)");
+               ND_PRINT("(unspec)");
+               ND_TCHECK_4(bp->refid);

                break;
 
        case PRIM_REF:
                break;
 
        case PRIM_REF:

-               if (fn_printn((u_char *)&(bp->refid), 4, snapend))
-                       goto trunc;
+               nd_printjn(ndo, (const u_char *)&(bp->refid), 4);

                break;
 
        case INFO_QUERY:
                break;
 
        case INFO_QUERY:

-               printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
+               ND_PRINT("%s INFO_QUERY", GET_IPADDR_STRING(bp->refid));

                /* this doesn't have more content */
                return;
 
        case INFO_REPLY:
                /* this doesn't have more content */
                return;
 
        case INFO_REPLY:

-               printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
+               ND_PRINT("%s INFO_REPLY", GET_IPADDR_STRING(bp->refid));

                /* this is too complex to be worth printing */
                return;
 
        default:
                /* this is too complex to be worth printing */
                return;
 
        default:

-               printf("%s", ipaddr_string(&(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", GET_BE_U_4(bp->refid));

                break;
        }
 
                break;
        }
 

-       TCHECK(bp->ref_timestamp);
-       fputs("\n\t  Reference Timestamp:  ", stdout);
-       p_ntp_time(&(bp->ref_timestamp));
-
-       TCHECK(bp->org_timestamp);
-       fputs("\n\t  Originator Timestamp: ", stdout);
-       p_ntp_time(&(bp->org_timestamp));
-
-       TCHECK(bp->rec_timestamp);
-       fputs("\n\t  Receive Timestamp:    ", stdout);
-       p_ntp_time(&(bp->rec_timestamp));
-
-       TCHECK(bp->xmt_timestamp);
-       fputs("\n\t  Transmit Timestamp:   ", stdout);
-       p_ntp_time(&(bp->xmt_timestamp));
-
-       fputs("\n\t    Originator - Receive Timestamp:  ", stdout);
-       p_ntp_delta(&(bp->org_timestamp), &(bp->rec_timestamp));
-
-       fputs("\n\t    Originator - Transmit Timestamp: ", stdout);
-       p_ntp_delta(&(bp->org_timestamp), &(bp->xmt_timestamp));
-
-       if ( (sizeof(struct ntpdata) - length) == 16) {         /* Optional: key-id */
-               TCHECK(bp->key_id);
-               printf("\n\tKey id: %u", bp->key_id);
-       } else if ( (sizeof(struct ntpdata) - length) == 0) {   /* Optional: key-id + authentication */
-               TCHECK(bp->key_id);
-               printf("\n\tKey id: %u", bp->key_id);
-               TCHECK2(bp->message_digest, sizeof (bp->message_digest));
-                printf("\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));
-        }
+       ND_PRINT("\n\t  Reference Timestamp:  ");
+       p_ntp_time(ndo, &(bp->ref_timestamp));
+
+       ND_PRINT("\n\t  Originator Timestamp: ");
+       p_ntp_time(ndo, &(bp->org_timestamp));
+
+       ND_PRINT("\n\t  Receive Timestamp:    ");
+       p_ntp_time(ndo, &(bp->rec_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));
+
+       if (version == 4)
+               efs_len = p_ext_fields(ndo, (const u_char *)bp + NTP_TIMEMSG_MINLEN, length - NTP_TIMEMSG_MINLEN);
+       else
+               efs_len = 0;
+
+       mac = (const u_char *)bp + NTP_TIMEMSG_MINLEN + efs_len;
+
+       if (length == NTP_TIMEMSG_MINLEN + efs_len + 4) {       /* Optional: key-id (crypto-NAK) */
+               ND_PRINT("\n\tKey id: %u", GET_BE_U_4(mac));
+       } else if (length == NTP_TIMEMSG_MINLEN + efs_len + 4 + 16) {   /* Optional: key-id + 128-bit digest */
+               ND_PRINT("\n\tKey id: %u", GET_BE_U_4(mac));
+               ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x",
+                        GET_BE_U_4(mac + 4),
+                        GET_BE_U_4(mac + 8),
+                        GET_BE_U_4(mac + 12),
+                        GET_BE_U_4(mac + 16));
+       } else if (length == NTP_TIMEMSG_MINLEN + efs_len + 4 + 20) {   /* Optional: key-id + 160-bit digest */
+               ND_PRINT("\n\tKey id: %u", GET_BE_U_4(mac));
+               ND_PRINT("\n\tAuthentication: %08x%08x%08x%08x%08x",
+                        GET_BE_U_4(mac + 4),
+                        GET_BE_U_4(mac + 8),
+                        GET_BE_U_4(mac + 12),
+                        GET_BE_U_4(mac + 16),
+                        GET_BE_U_4(mac + 20));
+       } else if (length > NTP_TIMEMSG_MINLEN + efs_len) {
+               ND_PRINT("\n\t(%u more bytes after the header and extension fields)",
+                               length - NTP_TIMEMSG_MINLEN - efs_len);
+       }

        return;
 
        return;
 

-trunc:
-       fputs(" [|ntp]", stdout);
+invalid:
+       nd_print_invalid(ndo);
+       ND_TCHECK_LEN(bp, length);

 }
 
 }
 

+/*
+ * Print NTP control message requests and responses
+ */

 static void
 static void

-p_sfix(register const struct s_fixedpt *sfp)
+ntp_control_print(netdissect_options *ndo,
+                 const struct ntp_control_data *cd, u_int length)

 {
 {

-       register int i;
-       register int f;
-       register float ff;
-
-       i = EXTRACT_16BITS(&sfp->int_part);
-       f = EXTRACT_16BITS(&sfp->fraction);
-       ff = f / 65536.0;       /* shift radix point by 16 bits */
-       f = ff * 1000000.0;     /* Treat fraction as parts per million */
-       printf("%d.%06d", i, f);
+       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);

 }
 
 }
 

-#define        FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */
+union ntpdata {
+       struct ntp_time_data    td;
+       struct ntp_control_data cd;
+};

 
 

-static void
-p_ntp_time(register const struct l_fixedpt *lfp)
+/*
+ * Print NTP requests, handling the common VN, LI, and Mode
+ */
+void
+ntp_print(netdissect_options *ndo,
+         const u_char *cp, u_int length)

 {
 {

-       register int32_t i;
-       register u_int32_t uf;
-       register u_int32_t f;
-       register float ff;
-
-       i = EXTRACT_32BITS(&lfp->int_part);
-       uf = EXTRACT_32BITS(&lfp->fraction);
-       ff = uf;
-       if (ff < 0.0)           /* some compilers are buggy */
-               ff += FMAXINT;
-       ff = ff / FMAXINT;      /* shift radix point by 32 bits */
-       f = ff * 1000000000.0;  /* treat fraction as parts per billion */
-       printf("%u.%09d", i, f);
-
-#ifdef HAVE_STRFTIME
-       /*
-        * print the time in human-readable format.
-        */
-       if (i) {
-           time_t seconds = i - JAN_1970;
-           struct tm *tm;
-           char time_buf[128];
-
-           tm = localtime(&seconds);
-           strftime(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S", tm);
-           printf (" (%s)", time_buf);
+       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, version);
+               break;
+
+       case MODE_CONTROL:
+               ntp_control_print(ndo, &bp->cd, length);
+               break;
+
+       default:
+               break;                  /* XXX: not implemented! */

        }
        }

-#endif
+}
+
+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
 }
 
 /* Prints time difference between *lfp and *olfp */
 static void

-p_ntp_delta(register const struct l_fixedpt *olfp,
-           register const struct l_fixedpt *lfp)
+p_ntp_delta(netdissect_options *ndo,
+           const struct l_fixedpt *olfp,
+           const struct l_fixedpt *lfp)

 {
 {

-       register int32_t i;
-       register u_int32_t u, uf;
-       register u_int32_t ou, ouf;
-       register u_int32_t f;
-       register float ff;
+       uint32_t u, uf;
+       uint32_t ou, ouf;
+       uint32_t i;
+       uint32_t f;
+       double ff;

        int signbit;
 
        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 = 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) {
        if (ou == 0 && ouf == 0) {

-               p_ntp_time(lfp);
+               p_ntp_time(ndo, lfp);

                return;
        }
 
                return;
        }
 

-       i = u - ou;
-
-       if (i > 0) {            /* new is definitely greater than old */
+       if (u > ou) {           /* new is definitely greater than old */

                signbit = 0;
                signbit = 0;

+               i = u - ou;

                f = uf - ouf;
                if (ouf > uf)   /* must borrow from high-order bits */
                        i -= 1;
                f = uf - ouf;
                if (ouf > uf)   /* must borrow from high-order bits */
                        i -= 1;

-       } else if (i < 0) {     /* new is definitely less than old */
+       } else if (u < ou) {    /* new is definitely less than old */

                signbit = 1;
                signbit = 1;

+               i = ou - u;

                f = ouf - uf;
                f = ouf - uf;

-               if (uf > ouf)   /* must carry into the high-order bits */
-                       i += 1;
-               i = -i;
+               if (uf > ouf)   /* must borrow from the high-order bits */
+                       i -= 1;

        } else {                /* int_part is zero */
        } else {                /* int_part is zero */

+               i = 0;

                if (uf > ouf) {
                        signbit = 0;
                        f = uf - ouf;
                if (uf > ouf) {
                        signbit = 0;
                        f = uf - ouf;


@@ -422,12 +518,86 @@ p_ntp_delta(register const struct l_fixedpt *olfp,
        ff = f;
        if (ff < 0.0)           /* some compilers are buggy */
                ff += FMAXINT;
        ff = f;
        if (ff < 0.0)           /* some compilers are buggy */
                ff += FMAXINT;

-       ff = ff / FMAXINT;      /* shift radix point by 32 bits */
-       f = ff * 1000000000.0;  /* treat fraction as parts per billion */
-       if (signbit)
-               putchar('-');
+       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
        else

-               putchar('+');
-       printf("%d.%09d", i, f);
+               ND_PRINT(" (1/%us)", 1U << -poll_interval);
+}
+
+/* Prints an NTPv4 extension field */
+static void
+p_ntp_ef(netdissect_options *ndo, u_int type, u_int length, const u_char *ef_body)
+{
+       ND_PRINT("\n\t  %s", tok2str(ntp_ef_types, "Unknown type", type));
+       ND_PRINT(" (0x%04x), length %u", type, length);
+
+       if (ndo->ndo_vflag > 2)
+               hex_print(ndo, "\n\t    ", ef_body, length - 4);
+       else {
+               /*
+                * If we're not going to print it, at least make sure
+                * it's present in the packet, so if ef_len is too long,
+                * we stop.
+                */
+               ND_TCHECK_LEN(ef_body, length - 4);
+       }

 }
 
 }
 

+/* Prints list of extension fields per RFC 7822 */
+static u_int
+p_ext_fields(netdissect_options *ndo, const u_char *cp, u_int length)
+{
+       const struct ntp_extension_field *ef;
+       u_int ef_type, ef_len, efs_len;
+       int first_ef;
+
+       first_ef = 1;
+       efs_len = 0;
+
+       /* RFC 7822 requires the last EF in the packet to have at least
+          28 octets to avoid ambiguity with MACs */
+       while (length - efs_len >= 28) {
+               ef = (const struct ntp_extension_field *)(cp + efs_len);
+               ef_type = GET_BE_U_2(ef->type);
+               ef_len = GET_BE_U_2(ef->length);
+
+               if (efs_len + ef_len > length || ef_len < 4 || ef_len % 4 != 0) {
+                       nd_print_invalid(ndo);
+                       break;
+               }
+
+               if (first_ef) {
+                       ND_PRINT("\n\tExtension fields:");
+                       first_ef = 0;
+               }
+
+               p_ntp_ef(ndo, ef_type, ef_len, (const u_char *)(ef + 1));
+
+               /*
+                * The entire extension field is guaranteed to be in the
+                * captured data, as p_ntp_ef() will longjmp out if it
+                * isn't.
+                *
+                * As the total length of the captured data fits in a
+                * u_int, this means that the total length of all the
+                * extension fields will fit in a u_int, so this will
+                * never overflow.
+                */
+               efs_len += ef_len;
+       }
+
+       return efs_len;
+}