1 /* $OpenBSD: print-ntp.c,v 1.9 2000/10/03 14:31:58 ho Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that: (1) source code distributions 9 * retain the above copyright notice and this paragraph in its entirety, (2) 10 * distributions including binary code include the above copyright notice and 11 * this paragraph in its entirety in the documentation or other materials 12 * provided with the distribution, and (3) all advertising materials mentioning 13 * features or use of this software display the following acknowledgement: 14 * ``This product includes software developed by the University of California, 15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 16 * the University nor the names of its contributors may be used to endorse 17 * or promote products derived from this software without specific prior 18 * written permission. 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 22 * 23 * Format and print ntp packets. 24 * By Jeffrey Mogul/DECWRL 25 * loosely based on print-bootp.c 26 */ 27 28 #ifndef lint 29 static const char rcsid[] = 30 "@(#) $Header: /home/cvs/src/usr.sbin/tcpdump/print-ntp.c,v 1.9 2000/10/03 14:31:58 ho Exp $ (LBL)"; 31 #endif 32 33 #include <sys/param.h> 34 #include <sys/time.h> 35 #include <sys/socket.h> 36 37 #ifdef __STDC__ 38 struct mbuf; 39 struct rtentry; 40 #endif 41 #include <net/if.h> 42 43 #include <netinet/in.h> 44 #include <netinet/if_ether.h> 45 46 #include <ctype.h> 47 #include <stdio.h> 48 #include <string.h> 49 50 #include "interface.h" 51 #include "addrtoname.h" 52 #ifdef MODEMASK 53 #undef MODEMASK /* Solaris sucks */ 54 #endif 55 #include "ntp.h" 56 57 static void p_sfix(const struct s_fixedpt *); 58 static void p_ntp_time(const struct l_fixedpt *); 59 static void p_ntp_delta(const struct l_fixedpt *, const struct l_fixedpt *); 60 61 /* 62 * Print ntp requests 63 */ 64 void 65 ntp_print(register const u_char *cp, u_int length) 66 { 67 register const struct ntpdata *bp; 68 int mode, version, leapind; 69 static char rclock[5]; 70 71 bp = (struct ntpdata *)cp; 72 /* Note funny sized packets */ 73 if (length != sizeof(struct ntpdata)) 74 (void)printf(" [len=%d]", length); 75 76 TCHECK(bp->status); 77 78 version = (int)(bp->status & VERSIONMASK) >> 3; 79 printf(" v%d", version); 80 81 leapind = bp->status & LEAPMASK; 82 switch (leapind) { 83 84 case NO_WARNING: 85 break; 86 87 case PLUS_SEC: 88 fputs(" +1s", stdout); 89 break; 90 91 case MINUS_SEC: 92 fputs(" -1s", stdout); 93 break; 94 } 95 96 mode = bp->status & MODEMASK; 97 switch (mode) { 98 99 case MODE_UNSPEC: /* unspecified */ 100 fputs(" unspec", stdout); 101 break; 102 103 case MODE_SYM_ACT: /* symmetric active */ 104 fputs(" sym_act", stdout); 105 break; 106 107 case MODE_SYM_PAS: /* symmetric passive */ 108 fputs(" sym_pas", stdout); 109 break; 110 111 case MODE_CLIENT: /* client */ 112 fputs(" client", stdout); 113 break; 114 115 case MODE_SERVER: /* server */ 116 fputs(" server", stdout); 117 break; 118 119 case MODE_BROADCAST: /* broadcast */ 120 fputs(" bcast", stdout); 121 break; 122 123 case MODE_RES1: /* reserved */ 124 fputs(" res1", stdout); 125 break; 126 127 case MODE_RES2: /* reserved */ 128 fputs(" res2", stdout); 129 break; 130 131 } 132 133 TCHECK(bp->stratum); 134 printf(" strat %d", bp->stratum); 135 136 TCHECK(bp->ppoll); 137 printf(" poll %d", bp->ppoll); 138 139 /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */ 140 TCHECK2(bp->distance, 0); 141 printf(" prec %d", bp->precision); 142 143 if (!vflag) 144 return; 145 146 TCHECK(bp->distance); 147 fputs(" dist ", stdout); 148 p_sfix(&bp->distance); 149 150 TCHECK(bp->dispersion); 151 fputs(" disp ", stdout); 152 p_sfix(&bp->dispersion); 153 154 TCHECK(bp->refid); 155 fputs(" ref ", stdout); 156 /* Interpretation depends on stratum */ 157 switch (bp->stratum) { 158 159 case UNSPECIFIED: 160 printf("(unspec)"); 161 break; 162 163 case PRIM_REF: 164 strncpy(rclock, (char *)&(bp->refid), 4); 165 rclock[4] = '\0'; 166 fputs(rclock, stdout); 167 break; 168 169 case INFO_QUERY: 170 printf("%s INFO_QUERY", ipaddr_string(&(bp->refid))); 171 /* this doesn't have more content */ 172 return; 173 174 case INFO_REPLY: 175 printf("%s INFO_REPLY", ipaddr_string(&(bp->refid))); 176 /* this is too complex to be worth printing */ 177 return; 178 179 default: 180 printf("%s", ipaddr_string(&(bp->refid))); 181 break; 182 } 183 184 TCHECK(bp->reftime); 185 putchar('@'); 186 p_ntp_time(&(bp->reftime)); 187 188 TCHECK(bp->org); 189 fputs(" orig ", stdout); 190 p_ntp_time(&(bp->org)); 191 192 TCHECK(bp->rec); 193 fputs(" rec ", stdout); 194 p_ntp_delta(&(bp->org), &(bp->rec)); 195 196 TCHECK(bp->xmt); 197 fputs(" xmt ", stdout); 198 p_ntp_delta(&(bp->org), &(bp->xmt)); 199 200 return; 201 202 trunc: 203 fputs(" [|ntp]", stdout); 204 } 205 206 static void 207 p_sfix(register const struct s_fixedpt *sfp) 208 { 209 register int i; 210 register int f; 211 register float ff; 212 213 i = ntohs(sfp->int_part); 214 f = ntohs(sfp->fraction); 215 ff = f / 65536.0; /* shift radix point by 16 bits */ 216 f = ff * 1000000.0; /* Treat fraction as parts per million */ 217 printf("%d.%06d", i, f); 218 } 219 220 #define FMAXINT (4294967296.0) /* floating point rep. of MAXINT */ 221 222 static void 223 p_ntp_time(register const struct l_fixedpt *lfp) 224 { 225 register int32_t i; 226 register u_int32_t uf; 227 register u_int32_t f; 228 register float ff; 229 230 i = ntohl(lfp->int_part); 231 uf = ntohl(lfp->fraction); 232 ff = uf; 233 if (ff < 0.0) /* some compilers are buggy */ 234 ff += FMAXINT; 235 ff = ff / FMAXINT; /* shift radix point by 32 bits */ 236 f = ff * 1000000000.0; /* treat fraction as parts per billion */ 237 printf("%u.%09d", i, f); 238 } 239 240 /* Prints time difference between *lfp and *olfp */ 241 static void 242 p_ntp_delta(register const struct l_fixedpt *olfp, 243 register const struct l_fixedpt *lfp) 244 { 245 register int32_t i; 246 register u_int32_t uf; 247 register u_int32_t ouf; 248 register u_int32_t f; 249 register float ff; 250 int signbit; 251 252 i = ntohl(lfp->int_part) - ntohl(olfp->int_part); 253 254 uf = ntohl(lfp->fraction); 255 ouf = ntohl(olfp->fraction); 256 257 if (i > 0) { /* new is definitely greater than old */ 258 signbit = 0; 259 f = uf - ouf; 260 if (ouf > uf) /* must borrow from high-order bits */ 261 i -= 1; 262 } else if (i < 0) { /* new is definitely less than old */ 263 signbit = 1; 264 f = ouf - uf; 265 if (uf > ouf) /* must carry into the high-order bits */ 266 i += 1; 267 i = -i; 268 } else { /* int_part is zero */ 269 if (uf > ouf) { 270 signbit = 0; 271 f = uf - ouf; 272 } else { 273 signbit = 1; 274 f = ouf - uf; 275 } 276 } 277 278 ff = f; 279 if (ff < 0.0) /* some compilers are buggy */ 280 ff += FMAXINT; 281 ff = ff / FMAXINT; /* shift radix point by 32 bits */ 282 f = ff * 1000000000.0; /* treat fraction as parts per billion */ 283 if (signbit) 284 putchar('-'); 285 else 286 putchar('+'); 287 printf("%d.%09d", i, f); 288 } 289