Merge from vendor branch SENDMAIL:
[dragonfly.git] / sys / kern / subr_log.c
CommitLineData
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1/*
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)subr_log.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: src/sys/kern/subr_log.c,v 1.39.2.2 2001/06/02 08:11:25 phk Exp $
e4c9c0c8 35 * $DragonFly: src/sys/kern/subr_log.c,v 1.7 2004/05/19 22:52:58 dillon Exp $
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36 */
37
38/*
39 * Error log buffer for kernel printf's.
40 */
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/conf.h>
45#include <sys/proc.h>
46#include <sys/vnode.h>
47#include <sys/filio.h>
48#include <sys/ttycom.h>
49#include <sys/msgbuf.h>
50#include <sys/signalvar.h>
51#include <sys/kernel.h>
52#include <sys/poll.h>
53#include <sys/filedesc.h>
54#include <sys/sysctl.h>
55
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56#define LOG_ASYNC 0x04
57#define LOG_RDWAIT 0x08
58
59static d_open_t logopen;
60static d_close_t logclose;
61static d_read_t logread;
62static d_ioctl_t logioctl;
63static d_poll_t logpoll;
64
65static void logtimeout(void *arg);
66
67#define CDEV_MAJOR 7
68static struct cdevsw log_cdevsw = {
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69 /* name */ "log",
70 /* maj */ CDEV_MAJOR,
71 /* flags */ 0,
72 /* port */ NULL,
455fcd7e 73 /* clone */ NULL,
fabb8ceb 74
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75 /* open */ logopen,
76 /* close */ logclose,
77 /* read */ logread,
78 /* write */ nowrite,
79 /* ioctl */ logioctl,
80 /* poll */ logpoll,
81 /* mmap */ nommap,
82 /* strategy */ nostrategy,
984263bc 83 /* dump */ nodump,
fabb8ceb 84 /* psize */ nopsize
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85};
86
87static struct logsoftc {
88 int sc_state; /* see above for possibilities */
89 struct selinfo sc_selp; /* process waiting on select call */
90 struct sigio *sc_sigio; /* information for async I/O */
91 struct callout sc_callout; /* callout to wakeup syslog */
92} logsoftc;
93
94int log_open; /* also used in log() */
95
96/* Times per second to check for a pending syslog wakeup. */
97static int log_wakeups_per_second = 5;
98SYSCTL_INT(_kern, OID_AUTO, log_wakeups_per_second, CTLFLAG_RW,
99 &log_wakeups_per_second, 0, "");
100
101/*ARGSUSED*/
102static int
41c20dac 103logopen(dev_t dev, int flags, int mode, struct thread *td)
984263bc 104{
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105 struct proc *p = td->td_proc;
106
107 KKASSERT(p != NULL);
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108 if (log_open)
109 return (EBUSY);
110 log_open = 1;
111 callout_init(&logsoftc.sc_callout);
112 fsetown(p->p_pid, &logsoftc.sc_sigio); /* signal process only */
113 callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
114 logtimeout, NULL);
115 return (0);
116}
117
118/*ARGSUSED*/
119static int
41c20dac 120logclose(dev_t dev, int flag, int mode, struct thread *td)
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121{
122
123 log_open = 0;
124 callout_stop(&logsoftc.sc_callout);
125 logsoftc.sc_state = 0;
126 funsetown(logsoftc.sc_sigio);
127 return (0);
128}
129
130/*ARGSUSED*/
131static int
132logread(dev_t dev, struct uio *uio, int flag)
133{
134 struct msgbuf *mbp = msgbufp;
135 long l;
136 int s;
137 int error = 0;
138
139 s = splhigh();
140 while (mbp->msg_bufr == mbp->msg_bufx) {
141 if (flag & IO_NDELAY) {
142 splx(s);
143 return (EWOULDBLOCK);
144 }
145 logsoftc.sc_state |= LOG_RDWAIT;
377d4740 146 if ((error = tsleep((caddr_t)mbp, PCATCH, "klog", 0))) {
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147 splx(s);
148 return (error);
149 }
150 }
151 splx(s);
152 logsoftc.sc_state &= ~LOG_RDWAIT;
153
154 while (uio->uio_resid > 0) {
155 l = mbp->msg_bufx - mbp->msg_bufr;
156 if (l < 0)
157 l = mbp->msg_size - mbp->msg_bufr;
158 l = min(l, uio->uio_resid);
159 if (l == 0)
160 break;
161 error = uiomove((caddr_t)msgbufp->msg_ptr + mbp->msg_bufr,
162 (int)l, uio);
163 if (error)
164 break;
165 mbp->msg_bufr += l;
166 if (mbp->msg_bufr >= mbp->msg_size)
167 mbp->msg_bufr = 0;
168 }
169 return (error);
170}
171
172/*ARGSUSED*/
173static int
41c20dac 174logpoll(dev_t dev, int events, struct thread *td)
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175{
176 int s;
177 int revents = 0;
178
179 s = splhigh();
180
181 if (events & (POLLIN | POLLRDNORM)) {
182 if (msgbufp->msg_bufr != msgbufp->msg_bufx)
183 revents |= events & (POLLIN | POLLRDNORM);
184 else
41c20dac 185 selrecord(td, &logsoftc.sc_selp);
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186 }
187 splx(s);
188 return (revents);
189}
190
191static void
192logtimeout(void *arg)
193{
194
195 if (!log_open)
196 return;
197 if (msgbuftrigger == 0) {
198 callout_reset(&logsoftc.sc_callout,
199 hz / log_wakeups_per_second, logtimeout, NULL);
200 return;
201 }
202 msgbuftrigger = 0;
203 selwakeup(&logsoftc.sc_selp);
204 if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL)
205 pgsigio(logsoftc.sc_sigio, SIGIO, 0);
206 if (logsoftc.sc_state & LOG_RDWAIT) {
207 wakeup((caddr_t)msgbufp);
208 logsoftc.sc_state &= ~LOG_RDWAIT;
209 }
210 callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
211 logtimeout, NULL);
212}
213
214/*ARGSUSED*/
215static int
41c20dac 216logioctl(dev_t dev, u_long com, caddr_t data, int flag, struct thread *td)
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217{
218 long l;
219 int s;
220
221 switch (com) {
222
223 /* return number of characters immediately available */
224 case FIONREAD:
225 s = splhigh();
226 l = msgbufp->msg_bufx - msgbufp->msg_bufr;
227 splx(s);
228 if (l < 0)
229 l += msgbufp->msg_size;
230 *(int *)data = l;
231 break;
232
233 case FIONBIO:
234 break;
235
236 case FIOASYNC:
237 if (*(int *)data)
238 logsoftc.sc_state |= LOG_ASYNC;
239 else
240 logsoftc.sc_state &= ~LOG_ASYNC;
241 break;
242
243 case FIOSETOWN:
244 return (fsetown(*(int *)data, &logsoftc.sc_sigio));
245
246 case FIOGETOWN:
247 *(int *)data = fgetown(logsoftc.sc_sigio);
248 break;
249
250 /* This is deprecated, FIOSETOWN should be used instead. */
251 case TIOCSPGRP:
252 return (fsetown(-(*(int *)data), &logsoftc.sc_sigio));
253
254 /* This is deprecated, FIOGETOWN should be used instead */
255 case TIOCGPGRP:
256 *(int *)data = -fgetown(logsoftc.sc_sigio);
257 break;
258
259 default:
260 return (ENOTTY);
261 }
262 return (0);
263}
264
265static void
266log_drvinit(void *unused)
267{
e4c9c0c8 268 cdevsw_add(&log_cdevsw, 0, 0);
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269 make_dev(&log_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "klog");
270}
271
272SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL)