savecore.c

早期freebsd实现

	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 (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(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) / 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(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);
}