savecore.c

早期freebsd实现

/*-
 * Copyright (c) 1986, 1992, 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 char copyright[] =
"@(#) Copyright (c) 1986, 1992, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)savecore.c	8.3 (Berkeley) 1/2/94";
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/syslog.h>
#include <sys/time.h>

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <nlist.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tzfile.h>
#include <unistd.h>

#define ok(number) ((number) - KERNBASE)

struct nlist current_nl[] = {	/* Namelist for currently running system. */
#define X_DUMPDEV	0
	{ "_dumpdev" },
#define X_DUMPLO	1
	{ "_dumplo" },
#define X_TIME		2
	{ "_time" },
#define	X_DUMPSIZE	3
	{ "_dumpsize" },
#define X_VERSION	4
	{ "_version" },
#define X_PANICSTR	5
	{ "_panicstr" },
#define	X_DUMPMAG	6
	{ "_dumpmag" },
	{ "" },
};
int cursyms[] = { X_DUMPDEV, X_DUMPLO, X_VERSION, X_DUMPMAG, -1 };
int dumpsyms[] = { X_TIME, X_DUMPSIZE, X_VERSION, X_PANICSTR, X_DUMPMAG, -1 };

struct nlist dump_nl[] = {	/* Name list for dumped system. */
	{ "_dumpdev" },		/* Entries MUST be the same as */
	{ "_dumplo" },		/*	those in current_nl[].  */
	{ "_time" },
	{ "_dumpsize" },
	{ "_version" },
	{ "_panicstr" },
	{ "_dumpmag" },
	{ "" },
};

/* Types match kernel declarations. */
long	dumplo;				/* where dump starts on dumpdev */
int	dumpmag;			/* magic number in dump */
int	dumpsize;			/* amount of memory dumped */

char	*vmunix;
char	*dirname;			/* directory to save dumps in */
char	*ddname;			/* name of dump device */
dev_t	dumpdev;			/* dump device */
int	dumpfd;				/* read/write descriptor on block dev */
time_t	now;				/* current date */
char	panic_mesg[1024];
int	panicstr;
char	vers[1024];

int	clear, compress, force, verbose;	/* flags */

void	 check_kmem __P((void));
int	 check_space __P((void));
void	 clear_dump __P((void));
int	 Create __P((char *, int));
int	 dump_exists __P((void));
char	*find_dev __P((dev_t, int));
int	 get_crashtime __P((void));
void	 kmem_setup __P((void));
void	 log __P((int, char *, ...));
void	 Lseek __P((int, off_t, int));
int	 Open __P((char *, int rw));
int	 Read __P((int, void *, int));
char	*rawname __P((char *s));
void	 save_core __P((void));
void	 usage __P((void));
void	 Write __P((int, void *, int));

int
main(argc, argv)
	int argc;
	char *argv[];
{
	int ch;

	openlog("savecore", LOG_PERROR, LOG_DAEMON);

	while ((ch = getopt(argc, argv, "cdfNvz")) != EOF)
		switch(ch) {
		case 'c':
			clear = 1;
			break;
		case 'd':		/* Not documented. */
		case 'v':
			verbose = 1;
			break;
		case 'f':
			force = 1;
			break;
		case 'N':
			vmunix = optarg;
			break;
		case 'z':
			compress = 1;
			break;
		case '?':
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (!clear) {
		if (argc != 1 && argc != 2)
			usage();
		dirname = argv[0];
	}
	if (argc == 2)
		vmunix = argv[1];

	(void)time(&now);
	kmem_setup();

	if (clear) {
		clear_dump();
		exit(0);
	}

	if (!dump_exists() && !force)
		exit(1);

	check_kmem();

	if (panicstr)
		syslog(LOG_ALERT, "reboot after panic: %s", panic_mesg);
	else
		syslog(LOG_ALERT, "reboot");

	if ((!get_crashtime() || !check_space()) && !force)
		exit(1);

	save_core();

	clear_dump();
	exit(0);
}

void
kmem_setup()
{
	FILE *fp;
	int kmem, i;
	char *dump_sys;
	
	/*
	 * Some names we need for the currently running system, others for
	 * the system that was running when the dump was made.  The values
	 * obtained from the current system are used to look for things in
	 * /dev/kmem that cannot be found in the dump_sys namelist, but are
	 * presumed to be the same (since the disk partitions are probably
	 * the same!)
	 */
	if ((nlist(_PATH_UNIX, current_nl)) == -1)
		syslog(LOG_ERR, "%s: nlist: %s", _PATH_UNIX, strerror(errno));
	for (i = 0; cursyms[i] != -1; i++)
		if (current_nl[cursyms[i]].n_value == 0) {
			syslog(LOG_ERR, "%s: %s not in namelist",
			    _PATH_UNIX, current_nl[cursyms[i]].n_name);
			exit(1);
		}

	dump_sys = vmunix ? vmunix : _PATH_UNIX;
	if ((nlist(dump_sys, dump_nl)) == -1)
		syslog(LOG_ERR, "%s: nlist: %s", dump_sys, strerror(errno));
	for (i = 0; dumpsyms[i] != -1; i++)
		if (dump_nl[dumpsyms[i]].n_value == 0) {
			syslog(LOG_ERR, "%s: %s not in namelist",
			    dump_sys, dump_nl[dumpsyms[i]].n_name);
			exit(1);
		}

	kmem = Open(_PATH_KMEM, O_RDONLY);
	Lseek(kmem, (off_t)current_nl[X_DUMPDEV].n_value, L_SET);
	(void)Read(kmem, &dumpdev, sizeof(dumpdev));
	if (dumpdev == NODEV) {
		syslog(LOG_WARNING, "no core dump (no dumpdev)");
		exit(1);
	}
	Lseek(kmem, (off_t)current_nl[X_DUMPLO].n_value, L_SET);
	(void)Read(kmem, &dumplo, sizeof(dumplo));
	if (verbose)
		(void)printf("dumplo = %d (%d * %d)\n",
		    dumplo, dumplo/DEV_BSIZE, DEV_BSIZE);
	Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET);
	(void)Read(kmem, &dumpmag, sizeof(dumpmag));
	dumplo *= DEV_BSIZE;
	ddname = find_dev(dumpdev, S_IFBLK);
	dumpfd = Open(ddname, O_RDWR);
	fp = fdopen(kmem, "r");
	if (fp == NULL) {
		syslog(LOG_ERR, "%s: fdopen: %m", _PATH_KMEM);
		exit(1);
	}
	if (vmunix)
		return;
	(void)fseek(fp, (off_t)current_nl[X_VERSION].n_value, L_SET);
	(void)fgets(vers, sizeof(vers), fp);

	/* Don't fclose(fp), we use dumpfd later. */
}

void
check_kmem()
{
	register char *cp;
	FILE *fp;
	char core_vers[1024];

	fp = fdopen(dumpfd, "r");
	if (fp == NULL) {
		syslog(LOG_ERR, "%s: fdopen: %m", ddname);
		exit(1);
	}
	fseek(fp, (off_t)(dumplo + ok(dump_nl[X_VERSION].n_value)), L_SET);
	fgets(core_vers, sizeof(core_vers), fp);
	if (strcmp(vers, core_vers) && vmunix == 0)
		syslog(LOG_WARNING,
		    "warning: %s version mismatch:\n\t%s\nand\t%s\n",
		    _PATH_UNIX, vers, core_vers);
	(void)fseek(fp,
	    (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), L_SET);
	(void)fread(&panicstr, sizeof(panicstr), 1, fp);
	if (panicstr) {
		(void)fseek(fp, dumplo + ok(panicstr), L_SET);
		cp = panic_mesg;
		do
			*cp = getc(fp);
		while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)]);
	}
	/* Don't fclose(fp), we use dumpfd later. */
}

void
clear_dump()
{
	long newdumplo;

	newdumplo = 0;
	Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET);
	Write(dumpfd, &newdumplo, sizeof(newdumplo));
}

int
dump_exists()
{
	int newdumpmag;

	Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET);
	(void)Read(dumpfd, &newdumpmag, sizeof(newdumpmag));
	if (newdumpmag != dumpmag) {
		if (verbose)
			syslog(LOG_WARNING, "magic number mismatch (%x != %x)",
			    newdumpmag, dumpmag);
		syslog(LOG_WARNING, "no core dump");
		return (0);
	}
	return (1);
}

char buf[1024 * 1024];

void
save_core()
{
	register FILE *fp;
	register int bounds, ifd, nr, nw, ofd;