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-rw-r--r--sys/kern/subr_log.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/sys/kern/subr_log.c b/sys/kern/subr_log.c
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+/*
+ * 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/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/conf.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/filio.h>
+#include <sys/ttycom.h>
+#include <sys/msgbuf.h>
+#include <sys/signalvar.h>
+#include <sys/kernel.h>
+#include <sys/poll.h>
+#include <sys/filedesc.h>
+#include <sys/sysctl.h>
+
+#define LOG_RDPRI (PZERO + 1)
+
+#define LOG_ASYNC 0x04
+#define LOG_RDWAIT 0x08
+
+static d_open_t logopen;
+static d_close_t logclose;
+static d_read_t logread;
+static d_ioctl_t logioctl;
+static d_poll_t logpoll;
+
+static void logtimeout(void *arg);
+
+#define CDEV_MAJOR 7
+static struct cdevsw log_cdevsw = {
+ .d_open = logopen,
+ .d_close = logclose,
+ .d_read = logread,
+ .d_ioctl = logioctl,
+ .d_poll = logpoll,
+ .d_name = "log",
+ .d_maj = CDEV_MAJOR,
+};
+
+static struct logsoftc {
+ int sc_state; /* see above for possibilities */
+ struct selinfo sc_selp; /* process waiting on select call */
+ struct sigio *sc_sigio; /* information for async I/O */
+ struct callout sc_callout; /* callout to wakeup syslog */
+} logsoftc;
+
+int log_open; /* also used in log() */
+
+/* Times per second to check for a pending syslog wakeup. */
+static int log_wakeups_per_second = 5;
+SYSCTL_INT(_kern, OID_AUTO, log_wakeups_per_second, CTLFLAG_RW,
+ &log_wakeups_per_second, 0, "");
+
+/*ARGSUSED*/
+static int
+logopen(dev_t dev, int flags, int mode, struct thread *td)
+{
+ if (log_open)
+ return (EBUSY);
+ log_open = 1;
+ callout_init(&logsoftc.sc_callout, 0);
+ fsetown(td->td_proc->p_pid, &logsoftc.sc_sigio); /* signal process only */
+ if (log_wakeups_per_second < 1) {
+ printf("syslog wakeup is less than one. Adjusting to 1.\n");
+ log_wakeups_per_second = 1;
+ }
+ callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
+ logtimeout, NULL);
+ return (0);
+}
+
+/*ARGSUSED*/
+static int
+logclose(dev_t dev, int flag, int mode, struct thread *td)
+{
+
+ log_open = 0;
+ callout_stop(&logsoftc.sc_callout);
+ logsoftc.sc_state = 0;
+ funsetown(&logsoftc.sc_sigio);
+ return (0);
+}
+
+/*ARGSUSED*/
+static int
+logread(dev_t dev, struct uio *uio, int flag)
+{
+ char buf[128];
+ struct msgbuf *mbp = msgbufp;
+ int error = 0, l, s;
+
+ s = splhigh();
+ while (msgbuf_getcount(mbp) == 0) {
+ if (flag & IO_NDELAY) {
+ splx(s);
+ return (EWOULDBLOCK);
+ }
+ logsoftc.sc_state |= LOG_RDWAIT;
+ if ((error = tsleep(mbp, LOG_RDPRI | PCATCH, "klog", 0))) {
+ splx(s);
+ return (error);
+ }
+ }
+ splx(s);
+ logsoftc.sc_state &= ~LOG_RDWAIT;
+
+ while (uio->uio_resid > 0) {
+ l = imin(sizeof(buf), uio->uio_resid);
+ l = msgbuf_getbytes(mbp, buf, l);
+ if (l == 0)
+ break;
+ error = uiomove(buf, l, uio);
+ if (error)
+ break;
+ }
+ return (error);
+}
+
+/*ARGSUSED*/
+static int
+logpoll(dev_t dev, int events, struct thread *td)
+{
+ int s;
+ int revents = 0;
+
+ s = splhigh();
+
+ if (events & (POLLIN | POLLRDNORM)) {
+ if (msgbuf_getcount(msgbufp) > 0)
+ revents |= events & (POLLIN | POLLRDNORM);
+ else
+ selrecord(td, &logsoftc.sc_selp);
+ }
+ splx(s);
+ return (revents);
+}
+
+static void
+logtimeout(void *arg)
+{
+
+ if (!log_open)
+ return;
+ if (log_wakeups_per_second < 1) {
+ printf("syslog wakeup is less than one. Adjusting to 1.\n");
+ log_wakeups_per_second = 1;
+ }
+ if (msgbuftrigger == 0) {
+ callout_reset(&logsoftc.sc_callout,
+ hz / log_wakeups_per_second, logtimeout, NULL);
+ return;
+ }
+ msgbuftrigger = 0;
+ selwakeup(&logsoftc.sc_selp);
+ if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL)
+ pgsigio(&logsoftc.sc_sigio, SIGIO, 0);
+ if (logsoftc.sc_state & LOG_RDWAIT) {
+ wakeup(msgbufp);
+ logsoftc.sc_state &= ~LOG_RDWAIT;
+ }
+ callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
+ logtimeout, NULL);
+}
+
+/*ARGSUSED*/
+static int
+logioctl(dev_t dev, u_long com, caddr_t data, int flag, struct thread *td)
+{
+
+ switch (com) {
+
+ /* return number of characters immediately available */
+ case FIONREAD:
+ *(int *)data = msgbuf_getcount(msgbufp);
+ break;
+
+ case FIONBIO:
+ break;
+
+ case FIOASYNC:
+ if (*(int *)data)
+ logsoftc.sc_state |= LOG_ASYNC;
+ else
+ logsoftc.sc_state &= ~LOG_ASYNC;
+ break;
+
+ case FIOSETOWN:
+ return (fsetown(*(int *)data, &logsoftc.sc_sigio));
+
+ case FIOGETOWN:
+ *(int *)data = fgetown(&logsoftc.sc_sigio);
+ break;
+
+ /* This is deprecated, FIOSETOWN should be used instead. */
+ case TIOCSPGRP:
+ return (fsetown(-(*(int *)data), &logsoftc.sc_sigio));
+
+ /* This is deprecated, FIOGETOWN should be used instead */
+ case TIOCGPGRP:
+ *(int *)data = -fgetown(&logsoftc.sc_sigio);
+ break;
+
+ default:
+ return (ENOTTY);
+ }
+ return (0);
+}
+
+static void
+log_drvinit(void *unused)
+{
+
+ make_dev(&log_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "klog");
+}
+
+SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL)
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