/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* This module contains functions used for reading and writing the scratch zone
* translation files. These files are used by Live Upgrade to keep track of
* mappings between actual kernel zone names and the zones in an alternate boot
* environment.
*
* The functions are MT-safe.
*
* The file format looks like this:
*
* <zonename> <kernel-zonename> <alt-root>
*
* The expected usage model is:
*
* fp = zonecfg_open_scratch("", B_TRUE);
* zonecfg_lock_scratch(fp);
* if (zonecfg_find_scratch(fp, zonename, altroot, NULL, 0) == 0) {
* handle error; zone already mounted
* }
* mount zone here
* zonecfg_add_scratch(fp, zonename, kernname, altroot);
* zonecfg_close_scratch(fp);
* fp = zonecfg_open_scratch(zoneroot, B_TRUE);
* ftruncate(fileno(fp), 0);
* zonecfg_add_scratch(fp, zonename, kernname, "/");
* zonecfg_close_scratch(fp);
*/
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <libzonecfg.h>
#define PATH_MAPFILE "tmp/.alt.lu-zone-map"
static int
lock_op(int fd, int type)
{
struct flock lock;
lock.l_type = type;
lock.l_whence = SEEK_SET;
lock.l_start = 0;
lock.l_len = 0;
return (fcntl(fd, F_SETLKW, &lock));
}
FILE *
zonecfg_open_scratch(const char *rootpath, boolean_t createfile)
{
mode_t oldmask = umask(0);
struct stat lbuf, fbuf;
int fd, flags;
FILE *fp;
char mapfile[MAXPATHLEN];
(void) snprintf(mapfile, sizeof (mapfile), "%s/" PATH_MAPFILE,
rootpath);
flags = O_RDWR | O_NOFOLLOW | O_NOLINKS;
if (createfile)
flags |= O_EXCL | O_CREAT;
if ((fd = open(mapfile, flags, 0644)) == -1) {
if (!createfile) {
errno = ENOENT;
goto failure;
}
if (lstat(mapfile, &lbuf) == -1)
goto failure;
if (!S_ISREG(lbuf.st_mode) || lbuf.st_nlink != 1 ||
lbuf.st_uid != 0) {
errno = EINVAL;
goto failure;
}
fd = open(mapfile, O_RDWR);
if (fd == -1)
goto failure;
if (fstat(fd, &fbuf) == -1)
goto failure;
if (lbuf.st_ino != fbuf.st_ino || lbuf.st_dev != fbuf.st_dev) {
errno = EINVAL;
goto failure;
}
}
if (lock_op(fd, F_RDLCK) == -1)
goto failure;
(void) umask(oldmask);
if ((fp = fdopen(fd, "r+")) == NULL)
(void) close(fd);
return (fp);
failure:
if (fd != -1)
(void) close(fd);
(void) umask(oldmask);
return (NULL);
}
int
zonecfg_lock_scratch(FILE *fp)
{
if (fflush(fp) != 0)
return (-1);
return (lock_op(fileno(fp), F_WRLCK));
}
void
zonecfg_close_scratch(FILE *fp)
{
(void) fclose(fp);
}
int
zonecfg_get_scratch(FILE *fp, char *zonename, size_t namelen, char *kernname,
size_t kernlen, char *altroot, size_t altlen)
{
char line[2 * ZONENAME_MAX + MAXPATHLEN + 2];
char *cp, *cp2;
/* We always hold at least a read lock on the file */
for (;;) {
if (fgets(line, sizeof (line), fp) == NULL)
return (-1);
if ((cp = strchr(line, '\n')) == NULL)
return (-1);
*cp = '\0';
if ((cp = strchr(line, ' ')) == NULL)
cp = line + strlen(line);
else
*cp++ = '\0';
if (zonename != NULL &&
strlcpy(zonename, line, namelen) >= namelen)
continue;
if ((cp2 = strchr(cp, ' ')) == NULL)
cp2 = cp + strlen(cp);
else
*cp2++ = '\0';
if (kernname != NULL &&
strlcpy(kernname, cp, kernlen) >= kernlen)
continue;
if (altroot != NULL && strlcpy(altroot, cp2, altlen) >= altlen)
continue;
break;
}
return (0);
}
int
zonecfg_find_scratch(FILE *fp, const char *zonename, const char *altroot,
char *kernzone, size_t kernlen)
{
char zone[ZONENAME_MAX];
char aroot[MAXPATHLEN];
rewind(fp);
while (zonecfg_get_scratch(fp, zone, sizeof (zone), kernzone, kernlen,
aroot, sizeof (aroot)) == 0) {
if (strcmp(zone, zonename) == 0 && strcmp(altroot, aroot) == 0)
return (0);
}
return (-1);
}
int
zonecfg_reverse_scratch(FILE *fp, const char *kernzone, char *zonename,
size_t namelen, char *altroot, size_t altlen)
{
char kzone[ZONENAME_MAX];
rewind(fp);
while (zonecfg_get_scratch(fp, zonename, namelen, kzone,
sizeof (kzone), altroot, altlen) == 0) {
if (strcmp(kzone, kernzone) == 0)
return (0);
}
return (-1);
}
int
zonecfg_add_scratch(FILE *fp, const char *zonename, const char *kernzone,
const char *altroot)
{
if (fseek(fp, 0, SEEK_END) == -1)
return (-1);
if (fprintf(fp, "%s %s %s\n", zonename, kernzone, altroot) == EOF)
return (-1);
if (fflush(fp) != 0)
return (-1);
return (0);
}
int
zonecfg_delete_scratch(FILE *fp, const char *kernzone)
{
char zone[ZONENAME_MAX];
char kzone[ZONENAME_MAX];
char aroot[MAXPATHLEN];
long roffs, woffs;
/*
* The implementation here is intentionally quite simple. We could
* allocate a buffer that's big enough to hold the data up to
* stat.st_size and then write back out the part we need to, but there
* seems to be little point.
*/
rewind(fp);
roffs = 0;
do {
woffs = roffs;
if (zonecfg_get_scratch(fp, NULL, 0, kzone, sizeof (kzone),
NULL, 0) != 0)
return (-1);
roffs = ftell(fp);
} while (strcmp(kzone, kernzone) != 0);
while (zonecfg_get_scratch(fp, zone, sizeof (zone), kzone,
sizeof (kzone), aroot, sizeof aroot) == 0) {
roffs = ftell(fp);
if (fseek(fp, woffs, SEEK_SET) == -1)
break;
if (fprintf(fp, "%s %s %s\n", zone, kzone, aroot) == EOF)
break;
woffs = ftell(fp);
if (fseek(fp, roffs, SEEK_SET) == -1)
break;
}
(void) ftruncate(fileno(fp), woffs);
return (0);
}
boolean_t
zonecfg_is_scratch(const char *kernzone)
{
return (strncmp(kernzone, "SUNWlu", 6) == 0);
}