subr_log.c revision 1.44
1/* $OpenBSD: subr_log.c,v 1.44 2016/05/19 09:40:30 bluhm Exp $ */ 2/* $NetBSD: subr_log.c,v 1.11 1996/03/30 22:24:44 christos Exp $ */ 3 4/* 5 * Copyright (c) 1982, 1986, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)subr_log.c 8.1 (Berkeley) 6/10/93 33 */ 34 35/* 36 * Error log buffer for kernel printf's. 37 */ 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/proc.h> 42#include <sys/vnode.h> 43#include <sys/ioctl.h> 44#include <sys/msgbuf.h> 45#include <sys/file.h> 46#include <sys/tty.h> 47#include <sys/signalvar.h> 48#include <sys/syslog.h> 49#include <sys/poll.h> 50#include <sys/malloc.h> 51#include <sys/filedesc.h> 52#include <sys/socket.h> 53#include <sys/socketvar.h> 54 55#ifdef KTRACE 56#include <sys/ktrace.h> 57#endif 58 59#include <sys/mount.h> 60#include <sys/syscallargs.h> 61 62#include <dev/cons.h> 63 64#define LOG_RDPRI (PZERO + 1) 65 66#define LOG_ASYNC 0x04 67#define LOG_RDWAIT 0x08 68 69struct logsoftc { 70 int sc_state; /* see above for possibilities */ 71 struct selinfo sc_selp; /* process waiting on select call */ 72 int sc_pgid; /* process/group for async I/O */ 73 uid_t sc_siguid; /* uid for process that set sc_pgid */ 74 uid_t sc_sigeuid; /* euid for process that set sc_pgid */ 75} logsoftc; 76 77int log_open; /* also used in log() */ 78int msgbufmapped; /* is the message buffer mapped */ 79struct msgbuf *msgbufp; /* the mapped buffer, itself. */ 80struct msgbuf *consbufp; /* console message buffer. */ 81struct file *syslogf; 82 83void filt_logrdetach(struct knote *kn); 84int filt_logread(struct knote *kn, long hint); 85 86struct filterops logread_filtops = 87 { 1, NULL, filt_logrdetach, filt_logread}; 88 89int dosendsyslog(struct proc *, const char *, size_t, int, enum uio_seg); 90 91void 92initmsgbuf(caddr_t buf, size_t bufsize) 93{ 94 struct msgbuf *mbp; 95 long new_bufs; 96 97 /* Sanity-check the given size. */ 98 if (bufsize < sizeof(struct msgbuf)) 99 return; 100 101 mbp = msgbufp = (struct msgbuf *)buf; 102 103 new_bufs = bufsize - offsetof(struct msgbuf, msg_bufc); 104 if ((mbp->msg_magic != MSG_MAGIC) || (mbp->msg_bufs != new_bufs) || 105 (mbp->msg_bufr < 0) || (mbp->msg_bufr >= mbp->msg_bufs) || 106 (mbp->msg_bufx < 0) || (mbp->msg_bufx >= mbp->msg_bufs)) { 107 /* 108 * If the buffer magic number is wrong, has changed 109 * size (which shouldn't happen often), or is 110 * internally inconsistent, initialize it. 111 */ 112 113 memset(buf, 0, bufsize); 114 mbp->msg_magic = MSG_MAGIC; 115 mbp->msg_bufs = new_bufs; 116 } 117 118 /* Always start new buffer data on a new line. */ 119 if (mbp->msg_bufx > 0 && mbp->msg_bufc[mbp->msg_bufx - 1] != '\n') 120 msgbuf_putchar(msgbufp, '\n'); 121 122 /* mark it as ready for use. */ 123 msgbufmapped = 1; 124} 125 126void 127initconsbuf(void) 128{ 129 long new_bufs; 130 131 /* Set up a buffer to collect /dev/console output */ 132 consbufp = malloc(CONSBUFSIZE, M_TEMP, M_NOWAIT|M_ZERO); 133 if (consbufp) { 134 new_bufs = CONSBUFSIZE - offsetof(struct msgbuf, msg_bufc); 135 consbufp->msg_magic = MSG_MAGIC; 136 consbufp->msg_bufs = new_bufs; 137 } 138} 139 140void 141msgbuf_putchar(struct msgbuf *mbp, const char c) 142{ 143 if (mbp->msg_magic != MSG_MAGIC) 144 /* Nothing we can do */ 145 return; 146 147 mbp->msg_bufc[mbp->msg_bufx++] = c; 148 mbp->msg_bufl = lmin(mbp->msg_bufl+1, mbp->msg_bufs); 149 if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs) 150 mbp->msg_bufx = 0; 151 /* If the buffer is full, keep the most recent data. */ 152 if (mbp->msg_bufr == mbp->msg_bufx) { 153 if (++mbp->msg_bufr >= mbp->msg_bufs) 154 mbp->msg_bufr = 0; 155 } 156} 157 158int 159logopen(dev_t dev, int flags, int mode, struct proc *p) 160{ 161 if (log_open) 162 return (EBUSY); 163 log_open = 1; 164 return (0); 165} 166 167int 168logclose(dev_t dev, int flag, int mode, struct proc *p) 169{ 170 171 if (syslogf) 172 FRELE(syslogf, p); 173 syslogf = NULL; 174 log_open = 0; 175 logsoftc.sc_state = 0; 176 return (0); 177} 178 179int 180logread(dev_t dev, struct uio *uio, int flag) 181{ 182 struct msgbuf *mbp = msgbufp; 183 size_t l; 184 int s; 185 int error = 0; 186 187 s = splhigh(); 188 while (mbp->msg_bufr == mbp->msg_bufx) { 189 if (flag & IO_NDELAY) { 190 splx(s); 191 return (EWOULDBLOCK); 192 } 193 logsoftc.sc_state |= LOG_RDWAIT; 194 error = tsleep(mbp, LOG_RDPRI | PCATCH, 195 "klog", 0); 196 if (error) { 197 splx(s); 198 return (error); 199 } 200 } 201 splx(s); 202 logsoftc.sc_state &= ~LOG_RDWAIT; 203 204 while (uio->uio_resid > 0) { 205 if (mbp->msg_bufx >= mbp->msg_bufr) 206 l = mbp->msg_bufx - mbp->msg_bufr; 207 else 208 l = mbp->msg_bufs - mbp->msg_bufr; 209 l = ulmin(l, uio->uio_resid); 210 if (l == 0) 211 break; 212 error = uiomove(&mbp->msg_bufc[mbp->msg_bufr], l, uio); 213 if (error) 214 break; 215 mbp->msg_bufr += l; 216 if (mbp->msg_bufr < 0 || mbp->msg_bufr >= mbp->msg_bufs) 217 mbp->msg_bufr = 0; 218 } 219 return (error); 220} 221 222int 223logpoll(dev_t dev, int events, struct proc *p) 224{ 225 int revents = 0; 226 int s = splhigh(); 227 228 if (events & (POLLIN | POLLRDNORM)) { 229 if (msgbufp->msg_bufr != msgbufp->msg_bufx) 230 revents |= events & (POLLIN | POLLRDNORM); 231 else 232 selrecord(p, &logsoftc.sc_selp); 233 } 234 splx(s); 235 return (revents); 236} 237 238int 239logkqfilter(dev_t dev, struct knote *kn) 240{ 241 struct klist *klist; 242 int s; 243 244 switch (kn->kn_filter) { 245 case EVFILT_READ: 246 klist = &logsoftc.sc_selp.si_note; 247 kn->kn_fop = &logread_filtops; 248 break; 249 default: 250 return (EINVAL); 251 } 252 253 kn->kn_hook = (void *)msgbufp; 254 255 s = splhigh(); 256 SLIST_INSERT_HEAD(klist, kn, kn_selnext); 257 splx(s); 258 259 return (0); 260} 261 262void 263filt_logrdetach(struct knote *kn) 264{ 265 int s = splhigh(); 266 267 SLIST_REMOVE(&logsoftc.sc_selp.si_note, kn, knote, kn_selnext); 268 splx(s); 269} 270 271int 272filt_logread(struct knote *kn, long hint) 273{ 274 struct msgbuf *p = (struct msgbuf *)kn->kn_hook; 275 276 kn->kn_data = (int)(p->msg_bufx - p->msg_bufr); 277 278 return (p->msg_bufx != p->msg_bufr); 279} 280 281void 282logwakeup(void) 283{ 284 if (!log_open) 285 return; 286 selwakeup(&logsoftc.sc_selp); 287 if (logsoftc.sc_state & LOG_ASYNC) 288 csignal(logsoftc.sc_pgid, SIGIO, 289 logsoftc.sc_siguid, logsoftc.sc_sigeuid); 290 if (logsoftc.sc_state & LOG_RDWAIT) { 291 wakeup(msgbufp); 292 logsoftc.sc_state &= ~LOG_RDWAIT; 293 } 294} 295 296int 297logioctl(dev_t dev, u_long com, caddr_t data, int flag, struct proc *p) 298{ 299 struct file *fp; 300 long l; 301 int error, s; 302 303 switch (com) { 304 305 /* return number of characters immediately available */ 306 case FIONREAD: 307 s = splhigh(); 308 l = msgbufp->msg_bufx - msgbufp->msg_bufr; 309 splx(s); 310 if (l < 0) 311 l += msgbufp->msg_bufs; 312 *(int *)data = l; 313 break; 314 315 case FIONBIO: 316 break; 317 318 case FIOASYNC: 319 if (*(int *)data) 320 logsoftc.sc_state |= LOG_ASYNC; 321 else 322 logsoftc.sc_state &= ~LOG_ASYNC; 323 break; 324 325 case TIOCSPGRP: 326 logsoftc.sc_pgid = *(int *)data; 327 logsoftc.sc_siguid = p->p_ucred->cr_ruid; 328 logsoftc.sc_sigeuid = p->p_ucred->cr_uid; 329 break; 330 331 case TIOCGPGRP: 332 *(int *)data = logsoftc.sc_pgid; 333 break; 334 335 case LIOCSFD: 336 if ((error = suser(p, 0)) != 0) 337 return (error); 338 if ((error = getsock(p, *(int *)data, &fp)) != 0) 339 return (error); 340 if (syslogf) 341 FRELE(syslogf, p); 342 syslogf = fp; 343 break; 344 345 default: 346 return (ENOTTY); 347 } 348 return (0); 349} 350 351int 352sys_osendsyslog(struct proc *p, void *v, register_t *retval) 353{ 354 struct sys_osendsyslog_args /* { 355 syscallarg(const void *) buf; 356 syscallarg(size_t) nbyte; 357 } */ *uap = v; 358 struct sys_sendsyslog_args oap; 359 360 SCARG(&oap, buf) = SCARG(uap, buf); 361 SCARG(&oap, nbyte) = SCARG(uap, nbyte); 362 SCARG(&oap, flags) = 0; 363 return sys_sendsyslog(p, &oap, retval); 364} 365 366int 367sys_sendsyslog(struct proc *p, void *v, register_t *retval) 368{ 369 struct sys_sendsyslog_args /* { 370 syscallarg(const void *) buf; 371 syscallarg(size_t) nbyte; 372 syscallarg(int) flags; 373 } */ *uap = v; 374 int error; 375#ifndef SMALL_KERNEL 376 static int dropped_count, orig_error; 377 int len; 378 char buf[64]; 379 380 if (dropped_count) { 381 len = snprintf(buf, sizeof(buf), 382 "<%d>sendsyslog: dropped %d message%s, error %d", 383 LOG_KERN|LOG_WARNING, dropped_count, 384 dropped_count == 1 ? "" : "s", orig_error); 385 error = dosendsyslog(p, buf, MIN((size_t)len, sizeof(buf) - 1), 386 0, UIO_SYSSPACE); 387 if (error == 0) 388 dropped_count = 0; 389 } 390#endif 391 error = dosendsyslog(p, SCARG(uap, buf), SCARG(uap, nbyte), 392 SCARG(uap, flags), UIO_USERSPACE); 393#ifndef SMALL_KERNEL 394 if (error) { 395 dropped_count++; 396 orig_error = error; 397 } 398#endif 399 return (error); 400} 401 402int 403dosendsyslog(struct proc *p, const char *buf, size_t nbyte, int flags, 404 enum uio_seg sflg) 405{ 406#ifdef KTRACE 407 struct iovec *ktriov = NULL; 408 int iovlen; 409#endif 410 char pri[6], *kbuf; 411 struct iovec aiov; 412 struct uio auio; 413 size_t i, len; 414 int error; 415 416 if (syslogf) 417 FREF(syslogf); 418 else if (!ISSET(flags, LOG_CONS)) 419 return (ENOTCONN); 420 else { 421 /* 422 * Strip off syslog priority when logging to console. 423 * LOG_PRIMASK | LOG_FACMASK is 0x03ff, so at most 4 424 * decimal digits may appear in priority as <1023>. 425 */ 426 len = MIN(nbyte, sizeof(pri)); 427 if (sflg == UIO_USERSPACE) { 428 if ((error = copyin(buf, pri, len))) 429 return (error); 430 } else 431 memcpy(pri, buf, len); 432 if (0 < len && pri[0] == '<') { 433 for (i = 1; i < len; i++) { 434 if (pri[i] < '0' || pri[i] > '9') 435 break; 436 } 437 if (i < len && pri[i] == '>') { 438 i++; 439 /* There must be at least one digit <0>. */ 440 if (i >= 3) { 441 buf += i; 442 nbyte -= i; 443 } 444 } 445 } 446 } 447 448 aiov.iov_base = (char *)buf; 449 aiov.iov_len = nbyte; 450 auio.uio_iov = &aiov; 451 auio.uio_iovcnt = 1; 452 auio.uio_segflg = sflg; 453 auio.uio_rw = UIO_WRITE; 454 auio.uio_procp = p; 455 auio.uio_offset = 0; 456 auio.uio_resid = aiov.iov_len; 457#ifdef KTRACE 458 if (KTRPOINT(p, KTR_GENIO)) { 459 ktriov = mallocarray(auio.uio_iovcnt, sizeof(struct iovec), 460 M_TEMP, M_WAITOK); 461 iovlen = auio.uio_iovcnt * sizeof (struct iovec); 462 463 memcpy(ktriov, auio.uio_iov, iovlen); 464 } 465#endif 466 467 len = auio.uio_resid; 468 if (syslogf) { 469 error = sosend(syslogf->f_data, NULL, &auio, NULL, NULL, 0); 470 if (error == 0) 471 len -= auio.uio_resid; 472 } else if (constty || cn_devvp) { 473 error = cnwrite(0, &auio, 0); 474 if (error == 0) 475 len -= auio.uio_resid; 476 aiov.iov_base = "\r\n"; 477 aiov.iov_len = 2; 478 auio.uio_iov = &aiov; 479 auio.uio_iovcnt = 1; 480 auio.uio_segflg = UIO_SYSSPACE; 481 auio.uio_rw = UIO_WRITE; 482 auio.uio_procp = p; 483 auio.uio_offset = 0; 484 auio.uio_resid = aiov.iov_len; 485 cnwrite(0, &auio, 0); 486 } else { 487 /* XXX console redirection breaks down... */ 488 if (sflg == UIO_USERSPACE) { 489 kbuf = malloc(len, M_TEMP, M_WAITOK); 490 error = copyin(aiov.iov_base, kbuf, len); 491 } else { 492 kbuf = aiov.iov_base; 493 error = 0; 494 } 495 if (error == 0) 496 for (i = 0; i < len; i++) { 497 if (kbuf[i] == '\0') 498 break; 499 cnputc(kbuf[i]); 500 auio.uio_resid--; 501 } 502 if (sflg == UIO_USERSPACE) 503 free(kbuf, M_TEMP, len); 504 if (error == 0) 505 len -= auio.uio_resid; 506 cnputc('\n'); 507 } 508 509#ifdef KTRACE 510 if (ktriov != NULL) { 511 if (error == 0) 512 ktrgenio(p, -1, UIO_WRITE, ktriov, len); 513 free(ktriov, M_TEMP, iovlen); 514 } 515#endif 516 if (syslogf) 517 FRELE(syslogf, p); 518 else 519 error = ENOTCONN; 520 return (error); 521} 522