freebsd-dev/sbin/dmesg/dmesg.c
Warner Losh fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

218 lines
6.2 KiB
C

/*-
* 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. 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.
*/
#if 0
#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
static const char sccsid[] = "@(#)dmesg.c 8.1 (Berkeley) 6/5/93";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/msgbuf.h>
#include <sys/sysctl.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <locale.h>
#include <nlist.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vis.h>
#include <sys/syslog.h>
static struct nlist nl[] = {
#define X_MSGBUF 0
{ "_msgbufp", 0, 0, 0, 0 },
{ NULL, 0, 0, 0, 0 },
};
void usage(void) __dead2;
#define KREAD(addr, var) \
kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var)
int
main(int argc, char *argv[])
{
struct msgbuf *bufp, cur;
char *bp, *ep, *memf, *nextp, *nlistf, *p, *q, *visbp;
kvm_t *kd;
size_t buflen, bufpos;
long pri;
int ch, clear;
bool all;
all = false;
clear = false;
(void) setlocale(LC_CTYPE, "");
memf = nlistf = NULL;
while ((ch = getopt(argc, argv, "acM:N:")) != -1)
switch(ch) {
case 'a':
all = true;
break;
case 'c':
clear = true;
break;
case 'M':
memf = optarg;
break;
case 'N':
nlistf = optarg;
break;
case '?':
default:
usage();
}
argc -= optind;
if (argc != 0)
usage();
if (memf == NULL) {
/*
* Running kernel. Use sysctl. This gives an unwrapped buffer
* as a side effect. Remove nulterm (if present) so the value
* returned by sysctl is formatted as the rest of the code
* expects (the same as the value read from a core file below).
*/
if (sysctlbyname("kern.msgbuf", NULL, &buflen, NULL, 0) == -1)
err(1, "sysctl kern.msgbuf");
/* Allocate extra room for growth between the sysctl calls. */
buflen += buflen/8;
/* Allocate more than sysctl sees, for room to append \n\0. */
if ((bp = malloc(buflen + 2)) == NULL)
errx(1, "malloc failed");
if (sysctlbyname("kern.msgbuf", bp, &buflen, NULL, 0) == -1)
err(1, "sysctl kern.msgbuf");
if (buflen > 0 && bp[buflen - 1] == '\0')
buflen--;
if (clear)
if (sysctlbyname("kern.msgbuf_clear", NULL, NULL, &clear, sizeof(int)))
err(1, "sysctl kern.msgbuf_clear");
} else {
/* Read in kernel message buffer and do sanity checks. */
kd = kvm_open(nlistf, memf, NULL, O_RDONLY, "dmesg");
if (kd == 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));
if (cur.msg_magic != MSG_MAGIC)
errx(1, "kernel message buffer has different magic "
"number");
if ((bp = malloc(cur.msg_size + 2)) == NULL)
errx(1, "malloc failed");
/* Unwrap the circular buffer to start from the oldest data. */
bufpos = MSGBUF_SEQ_TO_POS(&cur, cur.msg_wseq);
if (kvm_read(kd, (long)&cur.msg_ptr[bufpos], bp,
cur.msg_size - bufpos) != (ssize_t)(cur.msg_size - bufpos))
errx(1, "kvm_read: %s", kvm_geterr(kd));
if (bufpos != 0 && kvm_read(kd, (long)cur.msg_ptr,
&bp[cur.msg_size - bufpos], bufpos) != (ssize_t)bufpos)
errx(1, "kvm_read: %s", kvm_geterr(kd));
kvm_close(kd);
buflen = cur.msg_size;
}
/*
* Ensure that the buffer ends with a newline and a \0 to avoid
* complications below. We left space above.
*/
if (buflen == 0 || bp[buflen - 1] != '\n')
bp[buflen++] = '\n';
bp[buflen] = '\0';
if ((visbp = malloc(4 * buflen + 1)) == NULL)
errx(1, "malloc failed");
/*
* The message buffer is circular, but has been unwrapped so that
* the oldest data comes first. The data will be preceded by \0's
* if the message buffer was not full.
*/
p = bp;
ep = &bp[buflen];
if (*p == '\0') {
/* Strip leading \0's */
while (*p == '\0')
p++;
} else if (!all) {
/* Skip the first line, since it is probably incomplete. */
p = memchr(p, '\n', ep - p);
p++;
}
for (; p < ep; p = nextp) {
nextp = memchr(p, '\n', ep - p);
nextp++;
/* Skip ^<[0-9]+> syslog sequences. */
if (*p == '<' && isdigit(*(p+1))) {
errno = 0;
pri = strtol(p + 1, &q, 10);
if (*q == '>' && pri >= 0 && pri < INT_MAX &&
errno == 0) {
if (LOG_FAC(pri) != LOG_KERN && !all)
continue;
p = q + 1;
}
}
(void)strvisx(visbp, p, nextp - p, 0);
(void)printf("%s", visbp);
}
exit(0);
}
void
usage(void)
{
fprintf(stderr, "usage: dmesg [-ac] [-M core [-N system]]\n");
exit(1);
}