subr_log.c

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    1 /*      $OpenBSD: subr_log.c,v 1.75 2022/07/02 08:50:42 visa 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/malloc.h>
   50 #include <sys/filedesc.h>
   51 #include <sys/socket.h>
   52 #include <sys/socketvar.h>
   53 #include <sys/fcntl.h>
   54 #include <sys/mutex.h>
   55 #include <sys/timeout.h>
   56 
   57 #ifdef KTRACE
   58 #include <sys/ktrace.h>
   59 #endif
   60 
   61 #include <sys/mount.h>
   62 #include <sys/syscallargs.h>
   63 
   64 #include <dev/cons.h>
   65 
   66 #define LOG_RDPRI       (PZERO + 1)
   67 #define LOG_TICK        50              /* log tick interval in msec */
   68 
   69 #define LOG_ASYNC       0x04
   70 #define LOG_RDWAIT      0x08
   71 
   72 /*
   73  * Locking:
   74  *      L       log_mtx
   75  */
   76 struct logsoftc {
   77         int     sc_state;               /* [L] see above for possibilities */
   78         struct  selinfo sc_selp;        /* process waiting on select call */
   79         struct  sigio_ref sc_sigio;     /* async I/O registration */
   80         int     sc_need_wakeup;         /* if set, wake up waiters */
   81         struct timeout sc_tick;         /* wakeup poll timeout */
   82 } logsoftc;
   83 
   84 int     log_open;                       /* also used in log() */
   85 int     msgbufmapped;                   /* is the message buffer mapped */
   86 struct  msgbuf *msgbufp;                /* the mapped buffer, itself. */
   87 struct  msgbuf *consbufp;               /* console message buffer. */
   88 
   89 struct  file *syslogf;
   90 struct  rwlock syslogf_rwlock = RWLOCK_INITIALIZER("syslogf");
   91 
   92 /*
   93  * Lock that serializes access to log message buffers.
   94  * This should be kept as a leaf lock in order not to constrain where
   95  * printf(9) can be used.
   96  */
   97 struct  mutex log_mtx =
   98     MUTEX_INITIALIZER_FLAGS(IPL_HIGH, "logmtx", MTX_NOWITNESS);
   99 
  100 void filt_logrdetach(struct knote *kn);
  101 int filt_logread(struct knote *kn, long hint);
  102 
  103 const struct filterops logread_filtops = {
  104         .f_flags        = FILTEROP_ISFD,
  105         .f_attach       = NULL,
  106         .f_detach       = filt_logrdetach,
  107         .f_event        = filt_logread,
  108 };
  109 
  110 int dosendsyslog(struct proc *, const char *, size_t, int, enum uio_seg);
  111 void logtick(void *);
  112 size_t msgbuf_getlen(struct msgbuf *);
  113 void msgbuf_putchar_locked(struct msgbuf *, const char);
  114 
  115 void
  116 initmsgbuf(caddr_t buf, size_t bufsize)
  117 {
  118         struct msgbuf *mbp;
  119         long new_bufs;
  120 
  121         /* Sanity-check the given size. */
  122         if (bufsize < sizeof(struct msgbuf))
  123                 return;
  124 
  125         mbp = msgbufp = (struct msgbuf *)buf;
  126 
  127         new_bufs = bufsize - offsetof(struct msgbuf, msg_bufc);
  128         if ((mbp->msg_magic != MSG_MAGIC) || (mbp->msg_bufs != new_bufs) ||
  129             (mbp->msg_bufr < 0) || (mbp->msg_bufr >= mbp->msg_bufs) ||
  130             (mbp->msg_bufx < 0) || (mbp->msg_bufx >= mbp->msg_bufs)) {
  131                 /*
  132                  * If the buffer magic number is wrong, has changed
  133                  * size (which shouldn't happen often), or is
  134                  * internally inconsistent, initialize it.
  135                  */
  136 
  137                 memset(buf, 0, bufsize);
  138                 mbp->msg_magic = MSG_MAGIC;
  139                 mbp->msg_bufs = new_bufs;
  140         }
  141 
  142         /*
  143          * Always start new buffer data on a new line.
  144          * Avoid using log_mtx because mutexes do not work during early boot
  145          * on some architectures.
  146          */
  147         if (mbp->msg_bufx > 0 && mbp->msg_bufc[mbp->msg_bufx - 1] != '\n')
  148                 msgbuf_putchar_locked(mbp, '\n');
  149 
  150         /* mark it as ready for use. */
  151         msgbufmapped = 1;
  152 }
  153 
  154 void
  155 initconsbuf(void)
  156 {
  157         /* Set up a buffer to collect /dev/console output */
  158         consbufp = malloc(CONSBUFSIZE, M_TTYS, M_WAITOK | M_ZERO);
  159         consbufp->msg_magic = MSG_MAGIC;
  160         consbufp->msg_bufs = CONSBUFSIZE - offsetof(struct msgbuf, msg_bufc);
  161 }
  162 
  163 void
  164 msgbuf_putchar(struct msgbuf *mbp, const char c)
  165 {
  166         if (mbp->msg_magic != MSG_MAGIC)
  167                 /* Nothing we can do */
  168                 return;
  169 
  170         mtx_enter(&log_mtx);
  171         msgbuf_putchar_locked(mbp, c);
  172         mtx_leave(&log_mtx);
  173 }
  174 
  175 void
  176 msgbuf_putchar_locked(struct msgbuf *mbp, const char c)
  177 {
  178         mbp->msg_bufc[mbp->msg_bufx++] = c;
  179         if (mbp->msg_bufx < 0 || mbp->msg_bufx >= mbp->msg_bufs)
  180                 mbp->msg_bufx = 0;
  181         /* If the buffer is full, keep the most recent data. */
  182         if (mbp->msg_bufr == mbp->msg_bufx) {
  183                 if (++mbp->msg_bufr >= mbp->msg_bufs)
  184                         mbp->msg_bufr = 0;
  185                 mbp->msg_bufd++;
  186         }
  187 }
  188 
  189 size_t
  190 msgbuf_getlen(struct msgbuf *mbp)
  191 {
  192         long len;
  193 
  194         mtx_enter(&log_mtx);
  195         len = mbp->msg_bufx - mbp->msg_bufr;
  196         if (len < 0)
  197                 len += mbp->msg_bufs;
  198         mtx_leave(&log_mtx);
  199         return (len);
  200 }
  201 
  202 int
  203 logopen(dev_t dev, int flags, int mode, struct proc *p)
  204 {
  205         if (log_open)
  206                 return (EBUSY);
  207         log_open = 1;
  208         sigio_init(&logsoftc.sc_sigio);
  209         timeout_set(&logsoftc.sc_tick, logtick, NULL);
  210         timeout_add_msec(&logsoftc.sc_tick, LOG_TICK);
  211         return (0);
  212 }
  213 
  214 int
  215 logclose(dev_t dev, int flag, int mode, struct proc *p)
  216 {
  217         struct file *fp;
  218 
  219         rw_enter_write(&syslogf_rwlock);
  220         fp = syslogf;
  221         syslogf = NULL;
  222         rw_exit(&syslogf_rwlock);
  223 
  224         if (fp)
  225                 FRELE(fp, p);
  226         log_open = 0;
  227         timeout_del(&logsoftc.sc_tick);
  228         logsoftc.sc_state = 0;
  229         sigio_free(&logsoftc.sc_sigio);
  230         return (0);
  231 }
  232 
  233 int
  234 logread(dev_t dev, struct uio *uio, int flag)
  235 {
  236         struct sleep_state sls;
  237         struct msgbuf *mbp = msgbufp;
  238         size_t l, rpos;
  239         int error = 0;
  240 
  241         mtx_enter(&log_mtx);
  242         while (mbp->msg_bufr == mbp->msg_bufx) {
  243                 if (flag & IO_NDELAY) {
  244                         error = EWOULDBLOCK;
  245                         goto out;
  246                 }
  247                 logsoftc.sc_state |= LOG_RDWAIT;
  248                 mtx_leave(&log_mtx);
  249                 /*
  250                  * Set up and enter sleep manually instead of using msleep()
  251                  * to keep log_mtx as a leaf lock.
  252                  */
  253                 sleep_setup(&sls, mbp, LOG_RDPRI | PCATCH, "klog", 0);
  254                 error = sleep_finish(&sls, logsoftc.sc_state & LOG_RDWAIT);
  255                 mtx_enter(&log_mtx);
  256                 if (error)
  257                         goto out;
  258         }
  259 
  260         if (mbp->msg_bufd > 0) {
  261                 char buf[64];
  262                 long ndropped;
  263 
  264                 ndropped = mbp->msg_bufd;
  265                 mtx_leave(&log_mtx);
  266                 l = snprintf(buf, sizeof(buf),
  267                     "<%d>klog: dropped %ld byte%s, message buffer full\n",
  268                     LOG_KERN|LOG_WARNING, ndropped,
  269                     ndropped == 1 ? "" : "s");
  270                 error = uiomove(buf, ulmin(l, sizeof(buf) - 1), uio);
  271                 mtx_enter(&log_mtx);
  272                 if (error)
  273                         goto out;
  274                 mbp->msg_bufd -= ndropped;
  275         }
  276 
  277         while (uio->uio_resid > 0) {
  278                 if (mbp->msg_bufx >= mbp->msg_bufr)
  279                         l = mbp->msg_bufx - mbp->msg_bufr;
  280                 else
  281                         l = mbp->msg_bufs - mbp->msg_bufr;
  282                 l = ulmin(l, uio->uio_resid);
  283                 if (l == 0)
  284                         break;
  285                 rpos = mbp->msg_bufr;
  286                 mtx_leave(&log_mtx);
  287                 /* Ignore that concurrent readers may consume the same data. */
  288                 error = uiomove(&mbp->msg_bufc[rpos], l, uio);
  289                 mtx_enter(&log_mtx);
  290                 if (error)
  291                         break;
  292                 mbp->msg_bufr += l;
  293                 if (mbp->msg_bufr < 0 || mbp->msg_bufr >= mbp->msg_bufs)
  294                         mbp->msg_bufr = 0;
  295         }
  296  out:
  297         mtx_leave(&log_mtx);
  298         return (error);
  299 }
  300 
  301 int
  302 logkqfilter(dev_t dev, struct knote *kn)
  303 {
  304         struct klist *klist;
  305         int s;
  306 
  307         switch (kn->kn_filter) {
  308         case EVFILT_READ:
  309                 klist = &logsoftc.sc_selp.si_note;
  310                 kn->kn_fop = &logread_filtops;
  311                 break;
  312         default:
  313                 return (EINVAL);
  314         }
  315 
  316         kn->kn_hook = (void *)msgbufp;
  317 
  318         s = splhigh();
  319         klist_insert_locked(klist, kn);
  320         splx(s);
  321 
  322         return (0);
  323 }
  324 
  325 void
  326 filt_logrdetach(struct knote *kn)
  327 {
  328         int s;
  329 
  330         s = splhigh();
  331         klist_remove_locked(&logsoftc.sc_selp.si_note, kn);
  332         splx(s);
  333 }
  334 
  335 int
  336 filt_logread(struct knote *kn, long hint)
  337 {
  338         struct msgbuf *mbp = kn->kn_hook;
  339 
  340         kn->kn_data = msgbuf_getlen(mbp);
  341         return (kn->kn_data != 0);
  342 }
  343 
  344 void
  345 logwakeup(void)
  346 {
  347         /*
  348          * The actual wakeup has to be deferred because logwakeup() can be
  349          * called in very varied contexts.
  350          * Keep the print routines usable in as many situations as possible
  351          * by not using locking here.
  352          */
  353 
  354         /*
  355          * Ensure that preceding stores become visible to other CPUs
  356          * before the flag.
  357          */
  358         membar_producer();
  359 
  360         logsoftc.sc_need_wakeup = 1;
  361 }
  362 
  363 void
  364 logtick(void *arg)
  365 {
  366         int state;
  367 
  368         if (!log_open)
  369                 return;
  370 
  371         if (!logsoftc.sc_need_wakeup)
  372                 goto out;
  373         logsoftc.sc_need_wakeup = 0;
  374 
  375         /*
  376          * sc_need_wakeup has to be cleared before handling the wakeup.
  377          * Visiting log_mtx ensures the proper order.
  378          */
  379 
  380         mtx_enter(&log_mtx);
  381         state = logsoftc.sc_state;
  382         if (logsoftc.sc_state & LOG_RDWAIT)
  383                 logsoftc.sc_state &= ~LOG_RDWAIT;
  384         mtx_leave(&log_mtx);
  385 
  386         selwakeup(&logsoftc.sc_selp);
  387         if (state & LOG_ASYNC)
  388                 pgsigio(&logsoftc.sc_sigio, SIGIO, 0);
  389         if (state & LOG_RDWAIT)
  390                 wakeup(msgbufp);
  391 out:
  392         timeout_add_msec(&logsoftc.sc_tick, LOG_TICK);
  393 }
  394 
  395 int
  396 logioctl(dev_t dev, u_long com, caddr_t data, int flag, struct proc *p)
  397 {
  398         struct file *fp, *newfp;
  399         int error;
  400 
  401         switch (com) {
  402 
  403         /* return number of characters immediately available */
  404         case FIONREAD:
  405                 *(int *)data = (int)msgbuf_getlen(msgbufp);
  406                 break;
  407 
  408         case FIONBIO:
  409                 break;
  410 
  411         case FIOASYNC:
  412                 mtx_enter(&log_mtx);
  413                 if (*(int *)data)
  414                         logsoftc.sc_state |= LOG_ASYNC;
  415                 else
  416                         logsoftc.sc_state &= ~LOG_ASYNC;
  417                 mtx_leave(&log_mtx);
  418                 break;
  419 
  420         case FIOSETOWN:
  421         case TIOCSPGRP:
  422                 return (sigio_setown(&logsoftc.sc_sigio, com, data));
  423 
  424         case FIOGETOWN:
  425         case TIOCGPGRP:
  426                 sigio_getown(&logsoftc.sc_sigio, com, data);
  427                 break;
  428 
  429         case LIOCSFD:
  430                 if ((error = suser(p)) != 0)
  431                         return (error);
  432                 if ((error = getsock(p, *(int *)data, &newfp)) != 0)
  433                         return (error);
  434 
  435                 rw_enter_write(&syslogf_rwlock);
  436                 fp = syslogf;
  437                 syslogf = newfp;
  438                 rw_exit(&syslogf_rwlock);
  439 
  440                 if (fp)
  441                         FRELE(fp, p);
  442                 break;
  443 
  444         default:
  445                 return (ENOTTY);
  446         }
  447         return (0);
  448 }
  449 
  450 /*
  451  * If syslogd is not running, temporarily store a limited amount of messages
  452  * in kernel.  After log stash is full, drop messages and count them.  When
  453  * syslogd is available again, next log message will flush the stashed
  454  * messages and insert a message with drop count.  Calls to malloc(9) and
  455  * copyin(9) may sleep, protect data structures with rwlock.
  456  */
  457 
  458 #define LOGSTASH_SIZE   100
  459 struct logstash_message {
  460         char    *lgs_buffer;
  461         size_t   lgs_size;
  462 } logstash_messages[LOGSTASH_SIZE];
  463 
  464 struct  logstash_message *logstash_in = &logstash_messages[0];
  465 struct  logstash_message *logstash_out = &logstash_messages[0];
  466 
  467 struct  rwlock logstash_rwlock = RWLOCK_INITIALIZER("logstash");
  468 
  469 int     logstash_dropped, logstash_error, logstash_pid;
  470 
  471 int     logstash_insert(const char *, size_t, int, pid_t);
  472 void    logstash_remove(void);
  473 int     logstash_sendsyslog(struct proc *);
  474 
  475 static inline int
  476 logstash_full(void)
  477 {
  478         rw_assert_anylock(&logstash_rwlock);
  479 
  480         return logstash_out->lgs_buffer != NULL &&
  481             logstash_in == logstash_out;
  482 }
  483 
  484 static inline void
  485 logstash_increment(struct logstash_message **msg)
  486 {
  487         rw_assert_wrlock(&logstash_rwlock);
  488 
  489         KASSERT((*msg) >= &logstash_messages[0]);
  490         KASSERT((*msg) < &logstash_messages[LOGSTASH_SIZE]);
  491         if ((*msg) == &logstash_messages[LOGSTASH_SIZE - 1])
  492                 (*msg) = &logstash_messages[0];
  493         else
  494                 (*msg)++;
  495 }
  496 
  497 int
  498 logstash_insert(const char *buf, size_t nbyte, int logerror, pid_t pid)
  499 {
  500         int error;
  501 
  502         rw_enter_write(&logstash_rwlock);
  503 
  504         if (logstash_full()) {
  505                 if (logstash_dropped == 0) {
  506                         logstash_error = logerror;
  507                         logstash_pid = pid;
  508                 }
  509                 logstash_dropped++;
  510 
  511                 rw_exit(&logstash_rwlock);
  512                 return (0);
  513         }
  514 
  515         logstash_in->lgs_buffer = malloc(nbyte, M_LOG, M_WAITOK);
  516         error = copyin(buf, logstash_in->lgs_buffer, nbyte);
  517         if (error) {
  518                 free(logstash_in->lgs_buffer, M_LOG, nbyte);
  519                 logstash_in->lgs_buffer = NULL;
  520 
  521                 rw_exit(&logstash_rwlock);
  522                 return (error);
  523         }
  524         logstash_in->lgs_size = nbyte;
  525         logstash_increment(&logstash_in);
  526 
  527         rw_exit(&logstash_rwlock);
  528         return (0);
  529 }
  530 
  531 void
  532 logstash_remove(void)
  533 {
  534         rw_assert_wrlock(&logstash_rwlock);
  535 
  536         KASSERT(logstash_out->lgs_buffer != NULL);
  537         free(logstash_out->lgs_buffer, M_LOG, logstash_out->lgs_size);
  538         logstash_out->lgs_buffer = NULL;
  539         logstash_increment(&logstash_out);
  540 
  541         /* Insert dropped message in sequence where messages were dropped. */
  542         if (logstash_dropped) {
  543                 size_t l, nbyte;
  544                 char buf[80];
  545 
  546                 l = snprintf(buf, sizeof(buf),
  547                     "<%d>sendsyslog: dropped %d message%s, error %d, pid %d",
  548                     LOG_KERN|LOG_WARNING, logstash_dropped,
  549                     logstash_dropped == 1 ? "" : "s",
  550                     logstash_error, logstash_pid);
  551                 logstash_dropped = 0;
  552                 logstash_error = 0;
  553                 logstash_pid = 0;
  554 
  555                 /* Cannot fail, we have just freed a slot. */
  556                 KASSERT(!logstash_full());
  557                 nbyte = ulmin(l, sizeof(buf) - 1);
  558                 logstash_in->lgs_buffer = malloc(nbyte, M_LOG, M_WAITOK);
  559                 memcpy(logstash_in->lgs_buffer, buf, nbyte);
  560                 logstash_in->lgs_size = nbyte;
  561                 logstash_increment(&logstash_in);
  562         }
  563 }
  564 
  565 int
  566 logstash_sendsyslog(struct proc *p)
  567 {
  568         int error;
  569 
  570         rw_enter_write(&logstash_rwlock);
  571 
  572         while (logstash_out->lgs_buffer != NULL) {
  573                 error = dosendsyslog(p, logstash_out->lgs_buffer,
  574                     logstash_out->lgs_size, 0, UIO_SYSSPACE);
  575                 if (error) {
  576                         rw_exit(&logstash_rwlock);
  577                         return (error);
  578                 }
  579                 logstash_remove();
  580         }
  581 
  582         rw_exit(&logstash_rwlock);
  583         return (0);
  584 }
  585 
  586 /*
  587  * Send syslog(3) message from userland to socketpair(2) created by syslogd(8).
  588  * Store message in kernel log stash for later if syslogd(8) is not available
  589  * or sending fails.  Send to console if LOG_CONS is set and syslogd(8) socket
  590  * does not exist.
  591  */
  592 
  593 int
  594 sys_sendsyslog(struct proc *p, void *v, register_t *retval)
  595 {
  596         struct sys_sendsyslog_args /* {
  597                 syscallarg(const char *) buf;
  598                 syscallarg(size_t) nbyte;
  599                 syscallarg(int) flags;
  600         } */ *uap = v;
  601         size_t nbyte;
  602         int error;
  603 
  604         nbyte = SCARG(uap, nbyte);
  605         if (nbyte > LOG_MAXLINE)
  606                 nbyte = LOG_MAXLINE;
  607 
  608         logstash_sendsyslog(p);
  609         error = dosendsyslog(p, SCARG(uap, buf), nbyte, SCARG(uap, flags),
  610             UIO_USERSPACE);
  611         if (error && error != EFAULT)
  612                 logstash_insert(SCARG(uap, buf), nbyte, error, p->p_p->ps_pid);
  613         return (error);
  614 }
  615 
  616 int
  617 dosendsyslog(struct proc *p, const char *buf, size_t nbyte, int flags,
  618     enum uio_seg sflg)
  619 {
  620 #ifdef KTRACE
  621         struct iovec ktriov;
  622 #endif
  623         struct file *fp;
  624         char pri[6], *kbuf;
  625         struct iovec aiov;
  626         struct uio auio;
  627         size_t i, len;
  628         int error;
  629 
  630         /* Global variable syslogf may change during sleep, use local copy. */
  631         rw_enter_read(&syslogf_rwlock);
  632         fp = syslogf;
  633         if (fp)
  634                 FREF(fp);
  635         rw_exit(&syslogf_rwlock);
  636 
  637         if (fp == NULL) {
  638                 if (!ISSET(flags, LOG_CONS))
  639                         return (ENOTCONN);
  640                 /*
  641                  * Strip off syslog priority when logging to console.
  642                  * LOG_PRIMASK | LOG_FACMASK is 0x03ff, so at most 4
  643                  * decimal digits may appear in priority as <1023>.
  644                  */
  645                 len = MIN(nbyte, sizeof(pri));
  646                 if (sflg == UIO_USERSPACE) {
  647                         if ((error = copyin(buf, pri, len)))
  648                                 return (error);
  649                 } else
  650                         memcpy(pri, buf, len);
  651                 if (0 < len && pri[0] == '<') {
  652                         for (i = 1; i < len; i++) {
  653                                 if (pri[i] < '' || pri[i] > '9')
  654                                         break;
  655                         }
  656                         if (i < len && pri[i] == '>') {
  657                                 i++;
  658                                 /* There must be at least one digit <0>. */
  659                                 if (i >= 3) {
  660                                         buf += i;
  661                                         nbyte -= i;
  662                                 }
  663                         }
  664                 }
  665         }
  666 
  667         aiov.iov_base = (char *)buf;
  668         aiov.iov_len = nbyte;
  669         auio.uio_iov = &aiov;
  670         auio.uio_iovcnt = 1;
  671         auio.uio_segflg = sflg;
  672         auio.uio_rw = UIO_WRITE;
  673         auio.uio_procp = p;
  674         auio.uio_offset = 0;
  675         auio.uio_resid = aiov.iov_len;
  676 #ifdef KTRACE
  677         if (sflg == UIO_USERSPACE && KTRPOINT(p, KTR_GENIO))
  678                 ktriov = aiov;
  679         else
  680                 ktriov.iov_len = 0;
  681 #endif
  682 
  683         len = auio.uio_resid;
  684         if (fp) {
  685                 int flags = (fp->f_flag & FNONBLOCK) ? MSG_DONTWAIT : 0;
  686                 error = sosend(fp->f_data, NULL, &auio, NULL, NULL, flags);
  687                 if (error == 0)
  688                         len -= auio.uio_resid;
  689         } else {
  690                 KERNEL_LOCK();
  691                 if (constty || cn_devvp) {
  692                         error = cnwrite(0, &auio, 0);
  693                         if (error == 0)
  694                                 len -= auio.uio_resid;
  695                         aiov.iov_base = "\r\n";
  696                         aiov.iov_len = 2;
  697                         auio.uio_iov = &aiov;
  698                         auio.uio_iovcnt = 1;
  699                         auio.uio_segflg = UIO_SYSSPACE;
  700                         auio.uio_rw = UIO_WRITE;
  701                         auio.uio_procp = p;
  702                         auio.uio_offset = 0;
  703                         auio.uio_resid = aiov.iov_len;
  704                         cnwrite(0, &auio, 0);
  705                 } else {
  706                         /* XXX console redirection breaks down... */
  707                         if (sflg == UIO_USERSPACE) {
  708                                 kbuf = malloc(len, M_TEMP, M_WAITOK);
  709                                 error = copyin(aiov.iov_base, kbuf, len);
  710                         } else {
  711                                 kbuf = aiov.iov_base;
  712                                 error = 0;
  713                         }
  714                         if (error == 0)
  715                                 for (i = 0; i < len; i++) {
  716                                         if (kbuf[i] == '\0')
  717                                                 break;
  718                                         cnputc(kbuf[i]);
  719                                         auio.uio_resid--;
  720                                 }
  721                         if (sflg == UIO_USERSPACE)
  722                                 free(kbuf, M_TEMP, len);
  723                         if (error == 0)
  724                                 len -= auio.uio_resid;
  725                         cnputc('\n');
  726                 }
  727                 KERNEL_UNLOCK();
  728         }
  729 
  730 #ifdef KTRACE
  731         if (error == 0 && ktriov.iov_len != 0)
  732                 ktrgenio(p, -1, UIO_WRITE, &ktriov, len);
  733 #endif
  734         if (fp)
  735                 FRELE(fp, p);
  736         else if (error != EFAULT)
  737                 error = ENOTCONN;
  738         return (error);
  739 }
Cache object: 4d35c5c291a79b5ed71e6baec17ab676
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FreeBSD/Linux Kernel Cross Reference sys/kern/subr_log.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_log.c
