OpenBSD-4.6/sbin/savecore/savecore.c
/* $OpenBSD: savecore.c,v 1.47 2009/06/20 00:15:14 millert Exp $ */
/* $NetBSD: savecore.c,v 1.26 1996/03/18 21:16:05 leo 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. 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
#if 0
static char sccsid[] = "@(#)savecore.c 8.3 (Berkeley) 1/2/94";
#else
static char rcsid[] = "$OpenBSD: savecore.c,v 1.47 2009/06/20 00:15:14 millert Exp $";
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/syslog.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.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>
#include <limits.h>
#include <zlib.h>
#include <kvm.h>
#include <vis.h>
extern FILE *zopen(const char *fname, const char *mode, int bits);
#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_second" },
#define X_DUMPSIZE 3
{ "_dumpsize" },
#define X_VERSION 4
{ "_version" },
#define X_PANICSTR 5
{ "_panicstr" },
#define X_DUMPMAG 6
{ "_dumpmag" },
{ 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_second" },
{ "_dumpsize" },
{ "_version" },
{ "_panicstr" },
{ "_dumpmag" },
{ NULL },
};
/* Types match kernel declarations. */
long dumplo; /* where dump starts on dumpdev (in blocks) */
off_t dumpoff; /* where dump starts on dumpdev (in bytes) */
u_long dumpmag; /* magic number in dump */
int dumppages; /* amount of memory dumped (in pages) */
u_long dumpsize; /* amount of memory dumped */
char *kernel;
char *dirn; /* 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];
int panicstr;
char vers[1024];
int clear, zcompress, 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 Open(char *, int rw);
char *rawname(char *s);
void save_core(void);
void usage(void);
int
main(int argc, char *argv[])
{
struct rlimit rl;
int ch;
openlog("savecore", LOG_PERROR, LOG_DAEMON);
/* Increase our data size to the max if we can. */
if (getrlimit(RLIMIT_DATA, &rl) == 0) {
rl.rlim_cur = rl.rlim_max;
if (setrlimit(RLIMIT_DATA, &rl) < 0)
syslog(LOG_WARNING, "can't set rlimit data size: %m");
}
while ((ch = getopt(argc, argv, "cdfN:vz")) != -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':
zcompress = 1;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (!clear) {
if (argc != 1 && argc != 2)
usage();
dirn = argv[0];
}
if (argc == 2)
kernel = argv[1];
(void)time(&now);
kmem_setup();
if (clear) {
clear_dump();
return (0);
}
if (!dump_exists() && !force)
return (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)
return (1);
save_core();
clear_dump();
return (0);
}
char *dump_sys;
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 dump_sys namelist, but are
* presumed to be the same (since the disk partitions are probably
* the same!)
*/
kd_kern = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
if (kd_kern == NULL) {
syslog(LOG_ERR, "%s: kvm_openfiles: %s", _PATH_UNIX, errbuf);
exit(1);
}
if (kvm_nlist(kd_kern, current_nl) == -1)
syslog(LOG_ERR, "%s: kvm_nlist: %s", _PATH_UNIX,
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",
_PATH_UNIX, current_nl[cursyms[i]].n_name);
exit(1);
}
(void)KREAD(kd_kern, current_nl[X_DUMPDEV].n_value, &dumpdev);
if (dumpdev == NODEV) {
syslog(LOG_WARNING, "no core dump (no dumpdev)");
exit(1);
}
(void)KREAD(kd_kern, current_nl[X_DUMPLO].n_value, &dumplo);
dumpoff = (off_t)dumplo * DEV_BSIZE;
if (verbose)
(void)printf("dumpoff = %lld (%ld * %d)\n",
(long long)dumpoff, dumplo, DEV_BSIZE);
(void) KREAD(kd_kern, current_nl[X_DUMPMAG].n_value, &dumpmag);
if (kernel == NULL) {
if (kvm_read(kd_kern, current_nl[X_VERSION].n_value,
vers, sizeof(vers)) == -1) {
syslog(LOG_ERR, "%s: kvm_read: version misread", _PATH_UNIX);
exit(1);
}
vers[sizeof(vers) - 1] = '\0';
}
ddname = find_dev(dumpdev, S_IFBLK);
dumpfd = Open(ddname, O_RDWR);
dump_sys = kernel ? kernel : _PATH_UNIX;
kd_dump = kvm_openfiles(kernel, ddname, NULL, O_RDWR, errbuf);
if (kd_dump == NULL) {
syslog(LOG_ERR, "%s: kvm_openfiles: %s", dump_sys, errbuf);
exit(1);
}
if (kvm_nlist(kd_dump, dump_nl) == -1)
syslog(LOG_ERR, "%s: kvm_nlist: %s", dump_sys,
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",
dump_sys, dump_nl[dumpsyms[i]].n_name);
exit(1);
}
hdrsz = kvm_dump_mkheader(kd_dump, dumpoff);
if (hdrsz == -1) {
if(verbose)
syslog(LOG_ERR, "%s: kvm_dump_mkheader: %s", dump_sys,
kvm_geterr(kd_dump));
syslog(LOG_WARNING, "no core dump");
exit(1);
}
dumpoff += hdrsz;
kvm_close(kd_kern);
}
void
check_kmem(void)
{
char *cp;
int panicloc;
char core_vers[1024];
if (kvm_read(kd_dump, dump_nl[X_VERSION].n_value, core_vers,
sizeof(core_vers)) != sizeof(core_vers)) {
syslog(LOG_ERR, "%s: kvm_read: version misread", dump_sys);
exit(1);
}
core_vers[sizeof(core_vers) - 1] = '\0';
if (strcmp(vers, core_vers) && kernel == 0) {
vers[strcspn(vers, "\n")] = '\0';
core_vers[strcspn(core_vers, "\n")] = '\0';
syslog(LOG_WARNING,
"warning: %s version mismatch:\n\t%s\nand\t%s\n",
_PATH_UNIX, vers, core_vers);
}
(void)KREAD(kd_dump, dump_nl[X_PANICSTR].n_value, &panicstr);
if (panicstr) {
char c, visout[5];
size_t vislen;
cp = panic_mesg;
panicloc = panicstr;
for (;;) {
if (KREAD(kd_dump, panicloc, &c) != 0 || c == '\0')
break;
panicloc++;
vis(visout, c, VIS_SAFE|VIS_NOSLASH, 0);
vislen = strlen(visout);
if (cp - panic_mesg + vislen >= sizeof(panic_mesg))
break;
strlcat(cp, visout,
panic_mesg + sizeof panic_mesg - cp);
cp += strlen(cp);
}
}
}
int
dump_exists(void)
{
u_long newdumpmag;
(void)KREAD(kd_dump, dump_nl[X_DUMPMAG].n_value, &newdumpmag);
/* Read the dump size. */
(void)KREAD(kd_dump, dump_nl[X_DUMPSIZE].n_value, &dumppages);
dumpsize = (u_long)dumppages * 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 (%lx != %lx)",
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 = -1;
char *rawp, path[MAXPATHLEN];
mode_t um;
um = umask(S_IRWXG|S_IRWXO);
/*
* 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", dirn);
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);
}
/* Create the core file. */
(void)snprintf(path, sizeof(path), "%s%s.%d.core%s",
dirn, _PATH_UNIX, bounds, zcompress ? ".Z" : "");
if (zcompress) {
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);
fp = fdopen(ofd, "w");
if (fp == NULL) {
syslog(LOG_ERR, "%s: fdopen: %s", path, strerror(errno));
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, dumpoff, 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",
zcompress ? "compressed " : "", path);
for (; dumpsize != 0; dumpsize -= nr) {
(void)printf("%8luK\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;
}
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 ? kernel : _PATH_UNIX, O_RDONLY);
(void)snprintf(path, sizeof(path), "%s%s.%d%s",
dirn, _PATH_UNIX, bounds, zcompress ? ".Z" : "");
if (zcompress) {
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",
zcompress ? "compressed " : "", path);
while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
if (zcompress)
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: %s",
kernel ? kernel : _PATH_UNIX, strerror(errno));
syslog(LOG_WARNING,
"WARNING: kernel may be incomplete");
exit(1);
}
if (zcompress)
(void)fclose(fp);
else
(void)close(ofd);
(void)umask(um);
}
char *
find_dev(dev_t dev, int type)
{
DIR *dfd;
struct dirent *dir;
struct stat sb;
char *dp, devname[MAXPATHLEN];
if ((dfd = opendir(_PATH_DEV)) == NULL) {
syslog(LOG_ERR, "%s: %s", _PATH_DEV, strerror(errno));
exit(1);
}
(void)strlcpy(devname, _PATH_DEV, sizeof devname);
while ((dir = readdir(dfd))) {
(void)strlcpy(devname + sizeof(_PATH_DEV) - 1, dir->d_name,
sizeof devname - (sizeof(_PATH_DEV) - 1));
if (lstat(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(char *s)
{
char *sl, 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, "%s", strerror(errno));
exit(1);
}
return (sl);
}
int
get_crashtime(void)
{
time_t dumptime; /* Time the dump was taken. */
(void)KREAD(kd_dump, dump_nl[X_TIME].n_value, &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(void)
{
FILE *fp;
char *tkernel;
off_t minfree, spacefree, kernelsize, needed;
struct stat st;
struct statfs fsbuf;
char buf[100], path[MAXPATHLEN];
int fd;
tkernel = kernel ? kernel : _PATH_UNIX;
if (stat(tkernel, &st) < 0) {
syslog(LOG_ERR, "%s: %m", tkernel);
exit(1);
}
kernelsize = st.st_blocks * S_BLKSIZE;
if ((fd = open(dirn, O_RDONLY, 0)) < 0 || fstatfs(fd, &fsbuf) < 0) {
syslog(LOG_ERR, "%s: %m", dirn);
exit(1);
}
close(fd);
spacefree = ((off_t)fsbuf.f_bavail * fsbuf.f_bsize) / 1024;
(void)snprintf(path, sizeof(path), "%s/minfree", dirn);
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 + kernelsize) / 1024;
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(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
usage(void)
{
extern char *__progname;
fprintf(stderr, "usage: %s [-cfvz] [-N system] directory\n",
__progname);
exit(1);
}