NetBSD/sbin/savecore/savecore.c

800 lines
19 KiB
C

/* $NetBSD: savecore.c,v 1.59 2002/12/06 02:20:00 thorpej Exp $ */
/*-
* 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1986, 1992, 1993\n\
The Regents of the University of California. All rights reserved.\n");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)savecore.c 8.5 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: savecore.c,v 1.59 2002/12/06 02:20:00 thorpej Exp $");
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/msgbuf.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 <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tzfile.h>
#include <unistd.h>
#include <util.h>
#include <limits.h>
#include <kvm.h>
extern FILE *zopen(const char *fname, const char *mode);
#define KREAD(kd, addr, p)\
(kvm_read(kd, addr, (char *)(p), sizeof(*(p))) != sizeof(*(p)))
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_DUMPMAG 5
{ "_dumpmag" },
#define X_PANICSTR 6
{ "_panicstr" },
#define X_PANICSTART 7
{ "_panicstart" },
#define X_PANICEND 8
{ "_panicend" },
#define X_MSGBUF 9
{ "_msgbufp" },
{ NULL },
};
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" },
{ "_dumpmag" },
{ "_panicstr" },
{ "_panicstart" },
{ "_panicend" },
{ "_msgbufp" },
{ NULL },
};
/* Types match kernel declarations. */
off_t dumplo; /* where dump starts on dumpdev */
u_int32_t dumpmag; /* magic number in dump */
int dumpsize; /* amount of memory dumped */
const char *kernel; /* name of used kernel */
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 */
kvm_t *kd_dump; /* kvm descriptor on block dev */
time_t now; /* current date */
char panic_mesg[1024];
long panicstr;
char vers[1024];
char gzmode[3];
static int clear, compress, force, verbose; /* flags */
void check_kmem(void);
int check_space(void);
void clear_dump(void);
int Create(char *, int);
int dump_exists(void);
char *find_dev(dev_t, int);
int get_crashtime(void);
void kmem_setup(void);
void Lseek(int, off_t, int);
int main(int, char *[]);
int Open(const char *, int rw);
char *rawname(char *s);
void save_core(void);
void usage(void);
void Write(int, void *, int);
int
main(int argc, char *argv[])
{
int ch, level;
char *ep;
dirname = NULL;
kernel = NULL;
level = 1; /* default to fastest gzip compression */
gzmode[0] = 'w';
openlog("savecore", LOG_PERROR, LOG_DAEMON);
while ((ch = getopt(argc, argv, "cdfN:vzZ:")) != -1)
switch(ch) {
case 'c':
clear = 1;
break;
case 'd': /* Not documented. */
case 'v':
verbose = 1;
break;
case 'f':
force = 1;
break;
case 'N':
kernel = optarg;
break;
case 'z':
compress = 1;
break;
case 'Z':
level = (int)strtol(optarg, &ep, 10);
if (level < 0 || level > 9) {
(void)syslog(LOG_ERR, "invalid compression %s",
optarg);
usage();
}
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc != (clear ? 0 : 1))
usage();
gzmode[1] = level + '0';
if (!clear)
dirname = argv[0];
if (kernel == NULL) {
kernel = getbootfile();
}
(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(void)
{
kvm_t *kd_kern;
char errbuf[_POSIX2_LINE_MAX];
int i, hdrsz;
/*
* 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 kernel namelist, but are
* presumed to be the same (since the disk partitions are probably
* the same!)
*/
kd_kern = kvm_openfiles(kernel, NULL, NULL, O_RDONLY, errbuf);
if (kd_kern == NULL) {
syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
exit(1);
}
if (kvm_nlist(kd_kern, current_nl) == -1)
syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
kvm_geterr(kd_kern));
for (i = 0; cursyms[i] != -1; i++)
if (current_nl[cursyms[i]].n_value == 0) {
syslog(LOG_ERR, "%s: %s not in namelist",
kernel, current_nl[cursyms[i]].n_name);
exit(1);
}
if (KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
exit(1);
}
if (dumpdev == NODEV) {
syslog(LOG_WARNING, "no core dump (no dumpdev)");
exit(1);
}
{
long l_dumplo;
if (KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &l_dumplo) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
exit(1);
}
if (l_dumplo == -1) {
syslog(LOG_WARNING, "no core dump (invalid dumplo)");
exit(1);
}
dumplo = DEV_BSIZE * (off_t) l_dumplo;
}
if (verbose)
(void)printf("dumplo = %lld (%ld * %ld)\n",
(long long)dumplo, (long)(dumplo / DEV_BSIZE), (long)DEV_BSIZE);
if (KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_kern));
exit(1);
}
(void)kvm_read(kd_kern, current_nl[X_VERSION].n_value, vers,
sizeof(vers));
vers[sizeof(vers) - 1] = '\0';
ddname = find_dev(dumpdev, S_IFBLK);
dumpfd = Open(ddname, O_RDWR);
kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
if (kd_dump == NULL) {
syslog(LOG_ERR, "%s: kvm_openfiles: %s", kernel, errbuf);
exit(1);
}
if (kvm_nlist(kd_dump, dump_nl) == -1)
syslog(LOG_ERR, "%s: kvm_nlist: %s", kernel,
kvm_geterr(kd_dump));
for (i = 0; dumpsyms[i] != -1; i++)
if (dump_nl[dumpsyms[i]].n_value == 0) {
syslog(LOG_ERR, "%s: %s not in namelist",
kernel, dump_nl[dumpsyms[i]].n_name);
exit(1);
}
hdrsz = kvm_dump_mkheader(kd_dump, dumplo);
/*
* If 'hdrsz' == 0, kvm_dump_mkheader() failed on the magic-number
* checks, ergo no dump is present...
*/
if (hdrsz == 0) {
syslog(LOG_WARNING, "no core dump");
exit(1);
}
if (hdrsz == -1) {
syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", kernel,
kvm_geterr(kd_dump));
exit(1);
}
dumplo += hdrsz;
kvm_close(kd_kern);
}
void
check_kmem(void)
{
char *cp, *bufdata;
struct kern_msgbuf msgbuf, *bufp;
long panicloc, panicstart, panicend;
char core_vers[1024];
(void)kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
sizeof(core_vers));
core_vers[sizeof(core_vers) - 1] = '\0';
if (strcmp(vers, core_vers) != 0)
syslog(LOG_WARNING,
"warning: %s version mismatch:\n\t%s\nand\t%s\n",
kernel, vers, core_vers);
panicstart = panicend = 0;
if (KREAD(kd_dump, dump_nl[X_PANICSTART].n_value, &panicstart) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
goto nomsguf;
}
if (KREAD(kd_dump, dump_nl[X_PANICEND].n_value, &panicend) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
goto nomsguf;
}
if (panicstart != 0 && panicend != 0) {
if (KREAD(kd_dump, dump_nl[X_MSGBUF].n_value, &bufp)) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
goto nomsguf;
}
if (kvm_read(kd_dump, (long)bufp, &msgbuf,
offsetof(struct kern_msgbuf, msg_bufc)) !=
offsetof(struct kern_msgbuf, msg_bufc)) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
goto nomsguf;
}
if (msgbuf.msg_magic != MSG_MAGIC) {
if (verbose)
syslog(LOG_WARNING, "msgbuf magic incorrect");
goto nomsguf;
}
bufdata = malloc(msgbuf.msg_bufs);
if (bufdata == NULL) {
if (verbose)
syslog(LOG_WARNING, "couldn't allocate space for msgbuf data");
goto nomsguf;
}
if (kvm_read(kd_dump, (long)&bufp->msg_bufc, bufdata,
msgbuf.msg_bufs) != msgbuf.msg_bufs) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
goto nomsguf;
}
cp = panic_mesg;
while (panicstart != panicend && cp < &panic_mesg[sizeof(panic_mesg)-1]) {
*cp++ = bufdata[panicstart];
panicstart++;
if (panicstart >= msgbuf.msg_bufs)
panicstart = 0;
}
/* Don't end in a new-line */
cp = &panic_mesg[strlen(panic_mesg)] - 1;
if (*cp == '\n')
*cp = '\0';
panic_mesg[sizeof(panic_mesg) - 1] = '\0';
panicstr = 1; /* anything not zero */
return;
}
nomsguf:
if (KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
return;
}
if (panicstr) {
cp = panic_mesg;
panicloc = panicstr;
do {
if (KREAD(kd_dump, panicloc, cp) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s",
kvm_geterr(kd_dump));
break;
}
panicloc++;
} while (*cp++ && cp < &panic_mesg[sizeof(panic_mesg)-1]);
panic_mesg[sizeof(panic_mesg) - 1] = '\0';
}
}
int
dump_exists(void)
{
u_int32_t newdumpmag;
if (KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
return (0);
}
/* Read the dump size. */
if (KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumpsize) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
return (0);
}
dumpsize *= getpagesize();
/*
* Return zero if core dump doesn't seem to be there, and note
* it for syslog. This check and return happens after the dump size
* is read, so dumpsize is whether or not the core is valid (for -f).
*/
if (newdumpmag != dumpmag) {
if (verbose)
syslog(LOG_WARNING,
"magic number mismatch (0x%x != 0x%x)",
newdumpmag, dumpmag);
syslog(LOG_WARNING, "no core dump");
return (0);
}
return (1);
}
void
clear_dump(void)
{
if (kvm_dump_inval(kd_dump) == -1)
syslog(LOG_ERR, "%s: kvm_clear_dump: %s", ddname,
kvm_geterr(kd_dump));
}
char buf[1024 * 1024];
void
save_core(void)
{
FILE *fp;
int bounds, ifd, nr, nw, ofd;
char *rawp, path[MAXPATHLEN];
ofd = -1;
/*
* Get the current number and update the bounds file. Do the update
* now, because may fail later and don't want to overwrite anything.
*/
umask(066);
(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: %m", path);
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);
}
/* Create the core file. */
(void)snprintf(path, sizeof(path), "%s/netbsd.%d.core%s",
dirname, bounds, compress ? ".gz" : "");
if (compress) {
if ((fp = zopen(path, gzmode)) == NULL) {
syslog(LOG_ERR, "%s: %m", path);
exit(1);
}
} else {
ofd = Create(path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
fp = fdopen(ofd, "w");
if (fp == NULL) {
syslog(LOG_ERR, "%s: fdopen: %m", path);
exit(1);
}
}
/* 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;
}
/* Seek to the start of the core. */
Lseek(ifd, dumplo, SEEK_SET);
if (kvm_dump_wrtheader(kd_dump, fp, dumpsize) == -1) {
syslog(LOG_ERR, "kvm_dump_wrtheader: %s : %s", path,
kvm_geterr(kd_dump));
exit(1);
}
/* Copy the core file. */
syslog(LOG_NOTICE, "writing %score to %s",
compress ? "compressed " : "", path);
for (; dumpsize > 0; dumpsize -= nr) {
char nbuf[7];
humanize_number(nbuf, 7, dumpsize, "", HN_AUTOSCALE, 0);
(void)printf("%7s\r", nbuf);
(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;
}
nw = fwrite(buf, 1, nr, fp);
if (nw != nr) {
syslog(LOG_ERR, "%s: %s",
path, strerror(nw == 0 ? EIO : errno));
err2: syslog(LOG_WARNING,
"WARNING: core may be incomplete");
(void)printf("\n");
exit(1);
}
}
(void)close(ifd);
(void)fclose(fp);
/* Copy the kernel. */
ifd = Open(kernel, O_RDONLY);
(void)snprintf(path, sizeof(path), "%s/netbsd.%d%s",
dirname, bounds, compress ? ".gz" : "");
if (compress) {
if ((fp = zopen(path, gzmode)) == NULL) {
syslog(LOG_ERR, "%s: %m", path);
exit(1);
}
} else
ofd = Create(path, S_IRUSR | S_IWUSR);
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: kernel may be incomplete");
exit(1);
}
}
if (nr < 0) {
syslog(LOG_ERR, "%s: %m", kernel);
syslog(LOG_WARNING, "WARNING: kernel may be incomplete");
exit(1);
}
if (compress)
(void)fclose(fp);
else
(void)close(ofd);
}
char *
find_dev(dev_t dev, int type)
{
DIR *dfd;
struct dirent *dir;
struct stat sb;
char *dp, device[MAXPATHLEN + 1];
if ((dfd = opendir(_PATH_DEV)) == NULL) {
syslog(LOG_ERR, "%s: %m", _PATH_DEV);
exit(1);
}
(void)strcpy(device, _PATH_DEV);
while ((dir = readdir(dfd))) {
(void)strcpy(device + sizeof(_PATH_DEV) - 1, dir->d_name);
if (lstat(device, &sb)) {
syslog(LOG_ERR, "%s: %m", device);
continue;
}
if ((sb.st_mode & S_IFMT) != type)
continue;
if (dev == sb.st_rdev) {
closedir(dfd);
if ((dp = strdup(device)) == NULL) {
syslog(LOG_ERR, "%m");
exit(1);
}
return (dp);
}
}
closedir(dfd);
syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
exit(1);
}
char *
rawname(char *s)
{
char *sl;
char name[MAXPATHLEN];
if ((sl = strrchr(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", (int)(sl - s), s,
sl + 1);
if ((sl = strdup(name)) == NULL) {
syslog(LOG_ERR, "%m");
exit(1);
}
return (sl);
}
int
get_crashtime(void)
{
struct timeval dtime;
time_t dumptime; /* Time the dump was taken. */
if (KREAD(kd_dump, dump_nl[X_TIME].n_value, &dtime) != 0) {
if (verbose)
syslog(LOG_WARNING, "kvm_read: %s", kvm_geterr(kd_dump));
return (0);
}
dumptime = dtime.tv_sec;
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(void)
{
FILE *fp;
off_t minfree, spacefree, kernelsize, needed;
struct stat st;
struct statfs fsbuf;
char mbuf[100], path[MAXPATHLEN];
#ifdef __GNUC__
(void) &minfree;
#endif
if (stat(kernel, &st) < 0) {
syslog(LOG_ERR, "%s: %m", kernel);
exit(1);
}
kernelsize = st.st_blocks * S_BLKSIZE;
if (statfs(dirname, &fsbuf) < 0) {
syslog(LOG_ERR, "%s: %m", dirname);
exit(1);
}
spacefree = fsbuf.f_bavail;
spacefree *= fsbuf.f_bsize;
spacefree /= 1024;
(void)snprintf(path, sizeof(path), "%s/minfree", dirname);
if ((fp = fopen(path, "r")) == NULL)
minfree = 0;
else {
if (fgets(mbuf, sizeof(mbuf), fp) == NULL)
minfree = 0;
else
minfree = atoi(mbuf);
(void)fclose(fp);
}
needed = (dumpsize + kernelsize) / 1024;
if (minfree > 0 && spacefree - needed < minfree) {
syslog(LOG_WARNING,
"no dump, not enough free space in %s", dirname);
return (0);
}
if (spacefree - needed < minfree)
syslog(LOG_WARNING,
"dump performed, but free space threshold crossed");
return (1);
}
int
Open(const char *name, int rw)
{
int fd;
if ((fd = open(name, rw, 0)) < 0) {
syslog(LOG_ERR, "%s: %m", name);
exit(1);
}
return (fd);
}
void
Lseek(int fd, off_t off, int flag)
{
off_t ret;
ret = lseek(fd, off, flag);
if (ret == -1) {
syslog(LOG_ERR, "lseek: %m");
exit(1);
}
}
int
Create(char *file, int mode)
{
int fd;
fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode);
if (fd < 0) {
syslog(LOG_ERR, "%s: %m", file);
exit(1);
}
return (fd);
}
void
Write(int fd, void *bp, int size)
{
int n;
if ((n = write(fd, bp, size)) < size) {
syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO));
exit(1);
}
}
void
usage(void)
{
(void)syslog(LOG_ERR,
"usage: savecore [-cfvz] [-N system] [-Z level] directory");
exit(1);
}