diff options
Diffstat (limited to 'sbin/dmesg')
| -rw-r--r-- | sbin/dmesg/Makefile | 10 | ||||
| -rw-r--r-- | sbin/dmesg/dmesg.8 | 68 | ||||
| -rw-r--r-- | sbin/dmesg/dmesg.c | 168 |
3 files changed, 246 insertions, 0 deletions
diff --git a/sbin/dmesg/Makefile b/sbin/dmesg/Makefile new file mode 100644 index 000000000000..83a194ce0182 --- /dev/null +++ b/sbin/dmesg/Makefile @@ -0,0 +1,10 @@ +# @(#)Makefile 8.1 (Berkeley) 6/5/93 + +PROG= dmesg +MAN8= dmesg.8 +BINGRP= kmem +BINMODE=2555 +LDADD= -lkvm +DPADD= ${LIBKVM} + +.include <bsd.prog.mk> diff --git a/sbin/dmesg/dmesg.8 b/sbin/dmesg/dmesg.8 new file mode 100644 index 000000000000..b3648fcb8ba6 --- /dev/null +++ b/sbin/dmesg/dmesg.8 @@ -0,0 +1,68 @@ +.\" Copyright (c) 1980, 1991, 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. +.\" +.\" @(#)dmesg.8 8.1 (Berkeley) 6/5/93 +.\" +.Dd June 5, 1993 +.Dt DMESG 8 +.Os BSD 4 +.Sh NAME +.Nm dmesg +.Nd "display the system message buffer" +.Sh SYNOPSIS +.Nm dmesg +.Op Fl M Ar core +.Op Fl N Ar system +.Sh DESCRIPTION +.Nm Dmesg +displays the contents of the system message buffer. +.Pp +The options are as follows: +.Bl -tag -width Ds +.It Fl M +Extract values associated with the name list from the specified core +instead of the default ``/dev/kmem''. +.It Fl N +Extract the name list from the specified system instead of the default +``/kernel''. +.El +.Sh SEE ALSO +.Xr syslogd 8 +.Sh FILES +/dev/mem +/dev/kmem +/dev/drum +/kernel +.Sh HISTORY +The +.Nm +command appeared in +.Bx 4.0 . diff --git a/sbin/dmesg/dmesg.c b/sbin/dmesg/dmesg.c new file mode 100644 index 000000000000..b68a1d9e4eed --- /dev/null +++ b/sbin/dmesg/dmesg.c @@ -0,0 +1,168 @@ +/*- + * Copyright (c) 1991, 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. + */ + +#ifndef lint +static const char copyright[] = +"@(#) Copyright (c) 1991, 1993\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif /* not lint */ + +#ifndef lint +#if 0 +static const char sccsid[] = "@(#)dmesg.c 8.1 (Berkeley) 6/5/93"; +#endif +static const char rcsid[] = + "$Id$"; +#endif /* not lint */ + +#include <sys/cdefs.h> +#include <sys/msgbuf.h> + +#include <err.h> +#include <fcntl.h> +#include <kvm.h> +#include <limits.h> +#include <locale.h> +#include <nlist.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <unistd.h> +#include <vis.h> + +struct nlist nl[] = { +#define X_MSGBUF 0 + { "_msgbufp" }, + { NULL }, +}; + +void usage __P((void)); + +#define KREAD(addr, var) \ + kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var) + +int +main(argc, argv) + int argc; + char *argv[]; +{ + register int ch, newl, skip; + register char *p, *ep; + struct msgbuf *bufp, cur; + char *memf, *nlistf; + kvm_t *kd; + char buf[5]; + + (void) setlocale(LC_CTYPE, ""); + memf = nlistf = NULL; + while ((ch = getopt(argc, argv, "M:N:")) != EOF) + switch(ch) { + case 'M': + memf = optarg; + break; + case 'N': + nlistf = optarg; + break; + case '?': + default: + usage(); + } + argc -= optind; + argv += optind; + + /* + * Discard setgid privileges if not the running kernel so that bad + * guys can't print interesting stuff from kernel memory. + */ + if (memf != NULL || nlistf != NULL) + setgid(getgid()); + + /* Read in kernel message buffer, do sanity checks. */ + if ((kd = kvm_open(nlistf, memf, NULL, O_RDONLY, "dmesg")) == NULL) + exit (1); + if (kvm_nlist(kd, nl) == -1) + errx(1, "kvm_nlist: %s", kvm_geterr(kd)); + if (nl[X_MSGBUF].n_type == 0) + errx(1, "%s: msgbufp not found", nlistf ? nlistf : "namelist"); + if (KREAD(nl[X_MSGBUF].n_value, bufp) || KREAD((long)bufp, cur)) + errx(1, "kvm_read: %s", kvm_geterr(kd)); + kvm_close(kd); + if (cur.msg_magic != MSG_MAGIC) + errx(1, "magic number incorrect"); + if (cur.msg_bufx >= MSG_BSIZE) + cur.msg_bufx = 0; + + /* + * The message buffer is circular. If the buffer has wrapped, the + * write pointer points to the oldest data. Otherwise, the write + * pointer points to \0's following the data. Read the entire + * buffer starting at the write pointer and ignore nulls so that + * we effectively start at the oldest data. + */ + p = cur.msg_bufc + cur.msg_bufx; + ep = (cur.msg_bufx == 0 ? cur.msg_bufc + MSG_BSIZE : p); + newl = skip = 0; + do { + if (p == cur.msg_bufc + MSG_BSIZE) + p = cur.msg_bufc; + ch = *p; + /* Skip "\n<.*>" syslog sequences. */ + if (skip) { + if (ch == '>') + newl = skip = 0; + continue; + } + if (newl && ch == '<') { + skip = 1; + continue; + } + if (ch == '\0') + continue; + newl = ch == '\n'; + (void)vis(buf, ch, 0, 0); + if (buf[1] == 0) + (void)putchar(buf[0]); + else + (void)printf("%s", buf); + } while (++p != ep); + if (!newl) + (void)putchar('\n'); + exit(0); +} + +void +usage() +{ + (void)fprintf(stderr, "usage: dmesg [-M core] [-N system]\n"); + exit(1); +} |