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/* $OpenBSD: subr_log.c,v 1.7 2001/04/06 04:42:07 csapuntz Exp $ */
/* $NetBSD: subr_log.c,v 1.11 1996/03/30 22:24:44 christos Exp $ */
/*
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)subr_log.c 8.1 (Berkeley) 6/10/93
*/
/*
* Error log buffer for kernel printf's.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ioctl.h>
#include <sys/msgbuf.h>
#include <sys/file.h>
#include <sys/signalvar.h>
#include <sys/syslog.h>
#include <sys/conf.h>
#define LOG_RDPRI (PZERO + 1)
#define LOG_ASYNC 0x04
#define LOG_RDWAIT 0x08
struct logsoftc {
int sc_state; /* see above for possibilities */
struct selinfo sc_selp; /* process waiting on select call */
int sc_pgid; /* process/group for async I/O */
uid_t sc_siguid; /* uid for process that set sc_pgid */
uid_t sc_sigeuid; /* euid for process that set sc_pgid */
} logsoftc;
int log_open; /* also used in log() */
int msgbufmapped; /* is the message buffer mapped */
int msgbufenabled; /* is logging to the buffer enabled */
struct msgbuf *msgbufp; /* the mapped buffer, itself. */
void
initmsgbuf(buf, bufsize)
caddr_t buf;
size_t bufsize;
{
register struct msgbuf *mbp;
long new_bufs;
/* Sanity-check the given size. */
if (bufsize < sizeof(struct msgbuf))
return;
mbp = msgbufp = (struct msgbuf *)buf;
new_bufs = bufsize - offsetof(struct msgbuf, msg_bufc);
if ((mbp->msg_magic != MSG_MAGIC) || (mbp->msg_bufs != new_bufs) ||
(mbp->msg_bufr < 0) || (mbp->msg_bufr >= mbp->msg_bufs) ||
(mbp->msg_bufx < 0) || (mbp->msg_bufx >= mbp->msg_bufs)) {
/*
* If the buffer magic number is wrong, has changed
* size (which shouldn't happen often), or is
* internally inconsistent, initialize it.
*/
bzero(buf, bufsize);
mbp->msg_magic = MSG_MAGIC;
mbp->msg_bufs = new_bufs;
}
/* mark it as ready for use. */
msgbufmapped = msgbufenabled = 1;
}
/*ARGSUSED*/
int
logopen(dev, flags, mode, p)
dev_t dev;
int flags, mode;
struct proc *p;
{
if (log_open)
return (EBUSY);
log_open = 1;
return (0);
}
/*ARGSUSED*/
int
logclose(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
log_open = 0;
logsoftc.sc_state = 0;
return (0);
}
/*ARGSUSED*/
int
logread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
register struct msgbuf *mbp = msgbufp;
register long l;
register int s;
int error = 0;
s = splhigh();
while (mbp->msg_bufr == mbp->msg_bufx) {
if (flag & IO_NDELAY) {
splx(s);
return (EWOULDBLOCK);
}
logsoftc.sc_state |= LOG_RDWAIT;
error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH,
"klog", 0);
if (error) {
splx(s);
return (error);
}
}
splx(s);
logsoftc.sc_state &= ~LOG_RDWAIT;
while (uio->uio_resid > 0) {
l = mbp->msg_bufx - mbp->msg_bufr;
if (l < 0)
l = mbp->msg_bufs - mbp->msg_bufr;
l = min(l, uio->uio_resid);
if (l == 0)
break;
error = uiomove((caddr_t)&mbp->msg_bufc[mbp->msg_bufr],
(int)l, uio);
if (error)
break;
mbp->msg_bufr += l;
if (mbp->msg_bufr < 0 || mbp->msg_bufr >= mbp->msg_bufs)
mbp->msg_bufr = 0;
}
return (error);
}
/*ARGSUSED*/
int
logselect(dev, rw, p)
dev_t dev;
int rw;
struct proc *p;
{
int s = splhigh();
switch (rw) {
case FREAD:
if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
splx(s);
return (1);
}
selrecord(p, &logsoftc.sc_selp);
break;
}
splx(s);
return (0);
}
void
logwakeup()
{
if (!log_open)
return;
selwakeup(&logsoftc.sc_selp);
if (logsoftc.sc_state & LOG_ASYNC)
csignal(logsoftc.sc_pgid, SIGIO,
logsoftc.sc_siguid, logsoftc.sc_sigeuid);
if (logsoftc.sc_state & LOG_RDWAIT) {
wakeup((caddr_t)msgbufp);
logsoftc.sc_state &= ~LOG_RDWAIT;
}
}
/*ARGSUSED*/
int
logioctl(dev, com, data, flag, p)
dev_t dev;
u_long com;
caddr_t data;
int flag;
struct proc *p;
{
long l;
int s;
switch (com) {
/* return number of characters immediately available */
case FIONREAD:
s = splhigh();
l = msgbufp->msg_bufx - msgbufp->msg_bufr;
splx(s);
if (l < 0)
l += msgbufp->msg_bufs;
*(int *)data = l;
break;
case FIONBIO:
break;
case FIOASYNC:
if (*(int *)data)
logsoftc.sc_state |= LOG_ASYNC;
else
logsoftc.sc_state &= ~LOG_ASYNC;
break;
case TIOCSPGRP:
logsoftc.sc_pgid = *(int *)data;
logsoftc.sc_siguid = p->p_cred->p_ruid;
logsoftc.sc_sigeuid = p->p_ucred->cr_uid;
break;
case TIOCGPGRP:
*(int *)data = logsoftc.sc_pgid;
break;
default:
return (-1);
}
return (0);
}
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