dmesg.c revision 1.34
1 /* $NetBSD: dmesg.c,v 1.34 2018/09/19 00:15:05 christos Exp $ */ 2 /*- 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 #ifndef lint 33 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\ 34 The Regents of the University of California. All rights reserved."); 35 #endif /* not lint */ 36 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)dmesg.c 8.1 (Berkeley) 6/5/93"; 40 #else 41 __RCSID("$NetBSD: dmesg.c,v 1.34 2018/09/19 00:15:05 christos Exp $"); 42 #endif 43 #endif /* not lint */ 44 45 #include <sys/param.h> 46 #include <sys/msgbuf.h> 47 #include <sys/sysctl.h> 48 49 #include <err.h> 50 #include <ctype.h> 51 #include <fcntl.h> 52 #include <time.h> 53 #include <kvm.h> 54 #include <nlist.h> 55 #include <stdio.h> 56 #include <stddef.h> 57 #include <stdlib.h> 58 #include <unistd.h> 59 #include <vis.h> 60 61 #ifndef SMALL 62 static struct nlist nl[] = { 63 #define X_MSGBUF 0 64 { .n_name = "_msgbufp" }, 65 { .n_name = NULL }, 66 }; 67 68 __dead static void usage(void); 69 70 #define KREAD(addr, var) \ 71 kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var) 72 73 static const char * 74 fmtydhmsf(char *b, size_t l, time_t t, long nsec) 75 { 76 time_t s, m, h, d, M, y; 77 int z; 78 size_t o; 79 80 s = t % 60; 81 t /= 60; 82 83 m = t % 60; 84 t /= 60; 85 86 h = t % 24; 87 t /= 24; 88 89 d = t % 30; 90 t /= 30; 91 92 M = t % 12; 93 t /= 12; 94 95 y = t; 96 97 z = 0; 98 o = 0; 99 100 #define APPENDFMT(fmt, ...) \ 101 do { \ 102 z = snprintf(b + o, l - o, fmt, __VA_ARGS__); \ 103 if (z == -1) \ 104 return b; \ 105 o += (size_t)z; \ 106 if (o >= l) \ 107 return b; \ 108 } while (/*CONSTCOND*/0) 109 110 #define APPEND(a) \ 111 do if (a) \ 112 APPENDFMT("%jd%c", (intmax_t)a, toupper((unsigned char)__STRING(a)[0])); \ 113 while (/*CONSTCOND*/0) 114 #define APPENDS(a, s) \ 115 APPENDFMT("%jd.%ld%c", (intmax_t)a, s, \ 116 toupper((unsigned char)__STRING(a)[0])) 117 118 APPENDFMT("%s", "P"); 119 APPEND(y); 120 APPEND(M); 121 APPEND(d); 122 APPENDFMT("%s", "T"); 123 APPEND(h); 124 APPEND(m); 125 if (nsec) 126 nsec = nsec / 1000000; 127 if (nsec) 128 APPENDS(s, nsec); 129 else 130 APPEND(s); 131 return b; 132 } 133 134 static void 135 pnsec(long nsec, long fsec, int scale) 136 { 137 if (scale > 6) 138 printf("%6.6ld", (nsec + 499) / 1000); 139 else 140 printf("%*.*ld%.*s", scale, scale, fsec, 6 - scale, "000000"); 141 } 142 #endif 143 144 int 145 main(int argc, char *argv[]) 146 { 147 struct kern_msgbuf cur; 148 int ch, newl, log, i; 149 size_t tstamp, size; 150 char *p, *bufdata; 151 char buf[5]; 152 #ifndef SMALL 153 char tbuf[64]; 154 char *memf, *nlistf; 155 struct timeval boottime; 156 struct timespec lasttime; 157 intmax_t sec; 158 long nsec, fsec; 159 int scale; 160 int deltas, quiet, humantime; 161 bool frac; 162 163 static const int bmib[] = { CTL_KERN, KERN_BOOTTIME }; 164 size = sizeof(boottime); 165 166 boottime.tv_sec = 0; 167 boottime.tv_usec = 0; 168 lasttime.tv_sec = 0; 169 lasttime.tv_nsec = 0; 170 deltas = quiet = humantime = 0; 171 172 (void)sysctl(bmib, 2, &boottime, &size, NULL, 0); 173 174 memf = nlistf = NULL; 175 while ((ch = getopt(argc, argv, "dM:N:tT")) != -1) 176 switch(ch) { 177 case 'd': 178 deltas = 1; 179 break; 180 case 'M': 181 memf = optarg; 182 break; 183 case 'N': 184 nlistf = optarg; 185 break; 186 case 't': 187 quiet = 1; 188 break; 189 case 'T': 190 humantime++; 191 break; 192 case '?': 193 default: 194 usage(); 195 } 196 argc -= optind; 197 argv += optind; 198 if (quiet && humantime) 199 err(EXIT_FAILURE, "-t cannot be used with -T"); 200 201 if (memf == NULL) { 202 #endif 203 static const int mmib[2] = { CTL_KERN, KERN_MSGBUF }; 204 205 if (sysctl(mmib, 2, NULL, &size, NULL, 0) == -1 || 206 (bufdata = malloc(size)) == NULL || 207 sysctl(mmib, 2, bufdata, &size, NULL, 0) == -1) 208 err(1, "can't get msgbuf"); 209 210 /* make a dummy struct msgbuf for the display logic */ 211 cur.msg_bufx = 0; 212 cur.msg_bufs = size; 213 #ifndef SMALL 214 } else { 215 kvm_t *kd; 216 struct kern_msgbuf *bufp; 217 218 /* 219 * Read in message buffer header and data, and do sanity 220 * checks. 221 */ 222 kd = kvm_open(nlistf, memf, NULL, O_RDONLY, "dmesg"); 223 if (kd == NULL) 224 exit (1); 225 if (kvm_nlist(kd, nl) == -1) 226 errx(1, "kvm_nlist: %s", kvm_geterr(kd)); 227 if (nl[X_MSGBUF].n_type == 0) 228 errx(1, "%s: msgbufp not found", nlistf ? nlistf : 229 "namelist"); 230 if (KREAD(nl[X_MSGBUF].n_value, bufp)) 231 errx(1, "kvm_read: %s (0x%lx)", kvm_geterr(kd), 232 nl[X_MSGBUF].n_value); 233 if (kvm_read(kd, (long)bufp, &cur, 234 offsetof(struct kern_msgbuf, msg_bufc)) != 235 offsetof(struct kern_msgbuf, msg_bufc)) 236 errx(1, "kvm_read: %s (0x%lx)", kvm_geterr(kd), 237 (unsigned long)bufp); 238 if (cur.msg_magic != MSG_MAGIC) 239 errx(1, "magic number incorrect"); 240 bufdata = malloc(cur.msg_bufs); 241 if (bufdata == NULL) 242 errx(1, "couldn't allocate space for buffer data"); 243 if (kvm_read(kd, (long)&bufp->msg_bufc, bufdata, 244 cur.msg_bufs) != cur.msg_bufs) 245 errx(1, "kvm_read: %s", kvm_geterr(kd)); 246 kvm_close(kd); 247 if (cur.msg_bufx >= cur.msg_bufs) 248 cur.msg_bufx = 0; 249 } 250 #endif 251 252 /* 253 * The message buffer is circular; start at the write pointer 254 * (which points the oldest character), and go to the write 255 * pointer - 1 (which points the newest character). I.e, loop 256 * over cur.msg_bufs times. Unused area is skipped since it 257 * contains nul. 258 */ 259 #ifndef SMALL 260 frac = false; 261 scale = 0; 262 #endif 263 for (tstamp = 0, newl = 1, log = i = 0, p = bufdata + cur.msg_bufx; 264 i < cur.msg_bufs; i++, p++) { 265 266 #ifndef SMALL 267 if (p == bufdata + cur.msg_bufs) 268 p = bufdata; 269 #define ADDC(c) \ 270 do { \ 271 if (tstamp < sizeof(tbuf) - 1) \ 272 tbuf[tstamp++] = (c); \ 273 if (frac) \ 274 scale++; \ 275 } while (/*CONSTCOND*/0) 276 #else 277 #define ADDC(c) 278 #endif 279 ch = *p; 280 if (ch == '\0') 281 continue; 282 /* Skip "\n<.*>" syslog sequences. */ 283 /* Gather timestamp sequences */ 284 if (newl) { 285 #ifndef SMALL 286 int j; 287 #endif 288 289 switch (ch) { 290 case '[': 291 #ifndef SMALL 292 frac = false; 293 scale = 0; 294 #endif 295 ADDC(ch); 296 continue; 297 case '<': 298 log = 1; 299 continue; 300 case '>': 301 log = 0; 302 continue; 303 case ']': 304 #ifndef SMALL 305 frac = false; 306 #endif 307 ADDC(ch); 308 ADDC('\0'); 309 tstamp = 0; 310 #ifndef SMALL 311 sec = fsec = 0; 312 switch (sscanf(tbuf, "[%jd.%ld]", &sec, &fsec)){ 313 case EOF: 314 case 0: 315 /*???*/ 316 continue; 317 case 1: 318 fsec = 0; 319 break; 320 case 2: 321 break; 322 default: 323 /* Help */ 324 continue; 325 } 326 327 for (nsec = fsec, j = 9 - scale; --j >= 0; ) 328 nsec *= 10; 329 if (!quiet || deltas) 330 printf("["); 331 if (humantime == 1) { 332 time_t t; 333 struct tm tm; 334 335 t = boottime.tv_sec + sec; 336 if (localtime_r(&t, &tm) != NULL) { 337 strftime(tbuf, sizeof(tbuf), 338 "%a %b %e %H:%M:%S %Z %Y", 339 &tm); 340 printf("%s", tbuf); 341 } 342 } else if (humantime > 1) { 343 const char *fp = fmtydhmsf(tbuf, 344 sizeof(tbuf), sec, fsec); 345 if (fp) { 346 printf("%s", fp); 347 } 348 } else if (!quiet) { 349 printf(" %5jd.", sec); 350 pnsec(nsec, fsec, scale); 351 } 352 if (deltas) { 353 struct timespec nt = { sec, nsec }; 354 struct timespec dt; 355 356 timespecsub(&nt, &lasttime, &dt); 357 if (humantime || !quiet) 358 printf(" "); 359 printf("<% 4jd.%06ld>", (intmax_t) 360 dt.tv_sec, (dt.tv_nsec+499) / 1000); 361 lasttime = nt; 362 } 363 if (!quiet || deltas) 364 printf("] "); 365 #endif 366 continue; 367 case ' ': 368 if (!tstamp) 369 continue; 370 /*FALLTHROUGH*/ 371 default: 372 if (tstamp) { 373 ADDC(ch); 374 #ifndef SMALL 375 if (ch == '.') 376 frac = true; 377 #endif 378 continue; 379 } 380 if (log) 381 continue; 382 break; 383 } 384 newl = 0; 385 } 386 newl = ch == '\n'; 387 (void)vis(buf, ch, VIS_NOSLASH, 0); 388 #ifndef SMALL 389 if (buf[1] == 0) 390 (void)putchar(buf[0]); 391 else 392 #endif 393 (void)printf("%s", buf); 394 } 395 if (!newl) 396 (void)putchar('\n'); 397 return EXIT_SUCCESS; 398 } 399 400 #ifndef SMALL 401 static void 402 usage(void) 403 { 404 405 (void)fprintf(stderr, "Usage: %s [-dTt] [-M core] [-N system]\n", 406 getprogname()); 407 exit(EXIT_FAILURE); 408 } 409 #endif 410
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