4.4BSD/usr/src/sbin/savecore/savecore.c
/*-
* 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 8.1 (Berkeley) 6/5/93";
#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));
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;
char *rawp, path[MAXPATHLEN];
/*
* Get the current number and update the bounds file. Do the update
* now, because may fail later and don't want to overwrite anything.
*/
(void)snprintf(path, sizeof(path), "%s/bounds", dirname);
if ((fp = fopen(path, "r")) == NULL)
goto err1;
if (fgets(buf, sizeof(buf), fp) == NULL) {
if (ferror(fp))
err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno));
bounds = 0;
} else
bounds = atoi(buf);
if (fp != NULL)
(void)fclose(fp);
if ((fp = fopen(path, "w")) == NULL)
syslog(LOG_ERR, "%s: %m", path);
else {
(void)fprintf(fp, "%d\n", bounds + 1);
(void)fclose(fp);
}
(void)fclose(fp);
/* Create the core file. */
(void)snprintf(path, sizeof(path), "%s/vmcore.%d%s",
dirname, bounds, compress ? ".Z" : "");
if (compress) {
if ((fp = zopen(path, "w", 0)) == NULL) {
syslog(LOG_ERR, "%s: %s", path, strerror(errno));
exit(1);
}
} else
ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
/* Open the raw device. */
rawp = rawname(ddname);
if ((ifd = open(rawp, O_RDONLY)) == -1) {
syslog(LOG_WARNING, "%s: %m; using block device", rawp);
ifd = dumpfd;
}
/* Read the dump size. */
Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET);
(void)Read(dumpfd, &dumpsize, sizeof(dumpsize));
/* Seek to the start of the core. */
Lseek(ifd, (off_t)dumplo, L_SET);
/* Copy the core file. */
dumpsize *= NBPG;
syslog(LOG_NOTICE, "writing %score to %s",
compress ? "compressed " : "", path);
for (; dumpsize > 0; dumpsize -= nr) {
(void)printf("%6dK\r", dumpsize / 1024);
(void)fflush(stdout);
nr = read(ifd, buf, MIN(dumpsize, sizeof(buf)));
if (nr <= 0) {
if (nr == 0)
syslog(LOG_WARNING,
"WARNING: EOF on dump device");
else
syslog(LOG_ERR, "%s: %m", rawp);
goto err2;
}
if (compress)
nw = fwrite(buf, 1, nr, fp);
else
nw = write(ofd, buf, nr);
if (nw != nr) {
syslog(LOG_ERR, "%s: %s",
path, strerror(nw == 0 ? EIO : errno));
err2: syslog(LOG_WARNING,
"WARNING: vmcore may be incomplete");
(void)printf("\n");
exit(1);
}
}
(void)printf("\n");
(void)close(ifd);
if (compress)
(void)fclose(fp);
else
(void)close(ofd);
/* Copy the kernel. */
ifd = Open(vmunix ? vmunix : _PATH_UNIX, O_RDONLY);
(void)snprintf(path, sizeof(path), "%s/vmunix.%d%s",
dirname, bounds, compress ? ".Z" : "");
if (compress) {
if ((fp = zopen(path, "w", 0)) == NULL) {
syslog(LOG_ERR, "%s: %s", path, strerror(errno));
exit(1);
}
} else
ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
syslog(LOG_NOTICE, "writing %skernel to %s",
compress ? "compressed " : "", path);
while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
if (compress)
nw = fwrite(buf, 1, nr, fp);
else
nw = write(ofd, buf, nr);
if (nw != nr) {
syslog(LOG_ERR, "%s: %s",
path, strerror(nw == 0 ? EIO : errno));
syslog(LOG_WARNING,
"WARNING: vmunix may be incomplete");
exit(1);
}
}
if (nr < 0) {
syslog(LOG_ERR, "%s: %s",
vmunix ? vmunix : _PATH_UNIX, strerror(errno));
syslog(LOG_WARNING,
"WARNING: vmunix may be incomplete");
exit(1);
}
if (compress)
(void)fclose(fp);
else
(void)close(ofd);
}
char *
find_dev(dev, type)
register dev_t dev;
register int type;
{
register DIR *dfd;
struct dirent *dir;
struct stat sb;
char *dp, devname[MAXPATHLEN + 1];
if ((dfd = opendir(_PATH_DEV)) == NULL) {
syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno));
exit(1);
}
(void)strcpy(devname, _PATH_DEV);
while ((dir = readdir(dfd))) {
(void)strcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name);
if (stat(devname, &sb)) {
syslog(LOG_ERR, "%s: %s", devname, strerror(errno));
continue;
}
if ((sb.st_mode & S_IFMT) != type)
continue;
if (dev == sb.st_rdev) {
closedir(dfd);
if ((dp = strdup(devname)) == NULL) {
syslog(LOG_ERR, "%s", strerror(errno));
exit(1);
}
return (dp);
}
}
closedir(dfd);
syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
exit(1);
}
char *
rawname(s)
char *s;
{
char *sl, name[MAXPATHLEN];
if ((sl = rindex(s, '/')) == NULL || sl[1] == '0') {
syslog(LOG_ERR,
"can't make raw dump device name from %s", s);
return (s);
}
(void)snprintf(name, sizeof(name), "%.*s/r%s", sl - s, s, sl + 1);
if ((sl = strdup(name)) == NULL) {
syslog(LOG_ERR, "%s", strerror(errno));
exit(1);
}
return (sl);
}
int
get_crashtime()
{
time_t dumptime; /* Time the dump was taken. */
Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), L_SET);
(void)Read(dumpfd, &dumptime, sizeof(dumptime));
if (dumptime == 0) {
if (verbose)
syslog(LOG_ERR, "dump time is zero");
return (0);
}
(void)printf("savecore: system went down at %s", ctime(&dumptime));
#define LEEWAY (7 * SECSPERDAY)
if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
(void)printf("dump time is unreasonable\n");
return (0);
}
return (1);
}
int
check_space()
{
register FILE *fp;
char *tvmunix;
off_t minfree, spacefree, vmunixsize, needed;
struct stat st;
struct statfs fsbuf;
char buf[100], path[MAXPATHLEN];
tvmunix = vmunix ? vmunix : _PATH_UNIX;
if (stat(tvmunix, &st) < 0) {
syslog(LOG_ERR, "%s: %m", tvmunix);
exit(1);
}
vmunixsize = st.st_blocks * S_BLKSIZE;
if (statfs(dirname, &fsbuf) < 0) {
syslog(LOG_ERR, "%s: %m", dirname);
exit(1);
}
spacefree = (fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
if ((fp = fopen(path, "r")) == NULL)
minfree = 0;
else {
if (fgets(buf, sizeof(buf), fp) == NULL)
minfree = 0;
else
minfree = atoi(buf);
(void)fclose(fp);
}
needed = dumpsize + vmunixsize;
if (minfree > 0 && spacefree - needed < minfree) {
syslog(LOG_WARNING,
"no dump, not enough free space on device");
return (0);
}
if (spacefree - needed < minfree)
syslog(LOG_WARNING,
"dump performed, but free space threshold crossed");
return (1);
}
int
Open(name, rw)
char *name;
int rw;
{
int fd;
if ((fd = open(name, rw, 0)) < 0) {
syslog(LOG_ERR, "%s: %m", name);
exit(1);
}
return (fd);
}
int
Read(fd, bp, size)
int fd, size;
void *bp;
{
int nr;
nr = read(fd, bp, size);
if (nr != size) {
syslog(LOG_ERR, "read: %m");
exit(1);
}
return (nr);
}
void
Lseek(fd, off, flag)
int fd, flag;
off_t off;
{
off_t ret;
ret = lseek(fd, off, flag);
if (ret == -1) {
syslog(LOG_ERR, "lseek: %m");
exit(1);
}
}
int
Create(file, mode)
char *file;
int mode;
{
register int fd;
fd = creat(file, mode);
if (fd < 0) {
syslog(LOG_ERR, "%s: %m", file);
exit(1);
}
return (fd);
}
void
Write(fd, bp, size)
int fd, size;
void *bp;
{
int n;
if ((n = write(fd, bp, size)) < size) {
syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
exit(1);
}
}
void
usage()
{
(void)syslog(LOG_ERR, "usage: savecore [-cfvz] [-N system] directory");
exit(1);
}