freebsd-dev/sys/compat/linux/linux_mib.c
Jamie Gritton 7ae27ff49f Move the per-prison Linux MIB from a private one-off pointer to the new
OSD-based jail extensions.  This allows the Linux MIB to accessed via
jail_set and jail_get, and serves as a demonstration of adding jail support
to a module.

Reviewed by:	dchagin, kib
Approved by:	bz (mentor)
2009-05-07 18:36:47 +00:00

609 lines
15 KiB
C

/*-
* Copyright (c) 1999 Marcel Moolenaar
* 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
* in this position and unchanged.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/jail.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include "opt_compat.h"
#ifdef COMPAT_LINUX32
#include <machine/../linux32/linux.h>
#else
#include <machine/../linux/linux.h>
#endif
#include <compat/linux/linux_mib.h>
struct linux_prison {
char pr_osname[LINUX_MAX_UTSNAME];
char pr_osrelease[LINUX_MAX_UTSNAME];
int pr_oss_version;
int pr_use_linux26; /* flag to determine whether to use 2.6 emulation */
};
static unsigned linux_osd_jail_slot;
SYSCTL_NODE(_compat, OID_AUTO, linux, CTLFLAG_RW, 0,
"Linux mode");
static struct mtx osname_lock;
MTX_SYSINIT(linux_osname, &osname_lock, "linux osname", MTX_DEF);
static char linux_osname[LINUX_MAX_UTSNAME] = "Linux";
static int
linux_sysctl_osname(SYSCTL_HANDLER_ARGS)
{
char osname[LINUX_MAX_UTSNAME];
int error;
linux_get_osname(req->td, osname);
error = sysctl_handle_string(oidp, osname, LINUX_MAX_UTSNAME, req);
if (error || req->newptr == NULL)
return (error);
error = linux_set_osname(req->td, osname);
return (error);
}
SYSCTL_PROC(_compat_linux, OID_AUTO, osname,
CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
0, 0, linux_sysctl_osname, "A",
"Linux kernel OS name");
static char linux_osrelease[LINUX_MAX_UTSNAME] = "2.6.16";
static int linux_use_linux26 = 1;
static int
linux_sysctl_osrelease(SYSCTL_HANDLER_ARGS)
{
char osrelease[LINUX_MAX_UTSNAME];
int error;
linux_get_osrelease(req->td, osrelease);
error = sysctl_handle_string(oidp, osrelease, LINUX_MAX_UTSNAME, req);
if (error || req->newptr == NULL)
return (error);
error = linux_set_osrelease(req->td, osrelease);
return (error);
}
SYSCTL_PROC(_compat_linux, OID_AUTO, osrelease,
CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
0, 0, linux_sysctl_osrelease, "A",
"Linux kernel OS release");
static int linux_oss_version = 0x030600;
static int
linux_sysctl_oss_version(SYSCTL_HANDLER_ARGS)
{
int oss_version;
int error;
oss_version = linux_get_oss_version(req->td);
error = sysctl_handle_int(oidp, &oss_version, 0, req);
if (error || req->newptr == NULL)
return (error);
error = linux_set_oss_version(req->td, oss_version);
return (error);
}
SYSCTL_PROC(_compat_linux, OID_AUTO, oss_version,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
0, 0, linux_sysctl_oss_version, "I",
"Linux OSS version");
/*
* Returns holding the prison mutex if return non-NULL.
*/
static struct linux_prison *
linux_get_prison(struct thread *td, struct prison **prp)
{
struct prison *pr;
struct linux_prison *lpr;
KASSERT(td == curthread, ("linux_get_prison() called on !curthread"));
*prp = pr = td->td_ucred->cr_prison;
if (pr == NULL || !linux_osd_jail_slot)
return (NULL);
mtx_lock(&pr->pr_mtx);
lpr = osd_jail_get(pr, linux_osd_jail_slot);
if (lpr == NULL)
mtx_unlock(&pr->pr_mtx);
return (lpr);
}
/*
* Ensure a prison has its own Linux info. The prison should be locked on
* entrance and will be locked on exit (though it may get unlocked in the
* interrim).
*/
static int
linux_alloc_prison(struct prison *pr, struct linux_prison **lprp)
{
struct linux_prison *lpr, *nlpr;
int error;
/* If this prison already has Linux info, return that. */
error = 0;
mtx_assert(&pr->pr_mtx, MA_OWNED);
lpr = osd_jail_get(pr, linux_osd_jail_slot);
if (lpr != NULL)
goto done;
/*
* Allocate a new info record. Then check again, in case something
* changed during the allocation.
*/
mtx_unlock(&pr->pr_mtx);
nlpr = malloc(sizeof(struct linux_prison), M_PRISON, M_WAITOK);
mtx_lock(&pr->pr_mtx);
lpr = osd_jail_get(pr, linux_osd_jail_slot);
if (lpr != NULL) {
free(nlpr, M_PRISON);
goto done;
}
error = osd_jail_set(pr, linux_osd_jail_slot, nlpr);
if (error)
free(nlpr, M_PRISON);
else {
lpr = nlpr;
mtx_lock(&osname_lock);
strncpy(lpr->pr_osname, linux_osname, LINUX_MAX_UTSNAME);
strncpy(lpr->pr_osrelease, linux_osrelease, LINUX_MAX_UTSNAME);
lpr->pr_oss_version = linux_oss_version;
lpr->pr_use_linux26 = linux_use_linux26;
mtx_unlock(&osname_lock);
}
done:
if (lprp != NULL)
*lprp = lpr;
return (error);
}
/*
* Jail OSD methods for Linux prison data.
*/
static int
linux_prison_create(void *obj, void *data)
{
int error;
struct prison *pr = obj;
struct vfsoptlist *opts = data;
if (vfs_flagopt(opts, "nolinux", NULL, 0))
return (0);
/*
* Inherit a prison's initial values from its parent
* (different from NULL which also inherits changes).
*/
mtx_lock(&pr->pr_mtx);
error = linux_alloc_prison(pr, NULL);
mtx_unlock(&pr->pr_mtx);
return (error);
}
static int
linux_prison_check(void *obj __unused, void *data)
{
struct vfsoptlist *opts = data;
char *osname, *osrelease;
size_t len;
int error, oss_version;
/* Check that the parameters are correct. */
(void)vfs_flagopt(opts, "linux", NULL, 0);
(void)vfs_flagopt(opts, "nolinux", NULL, 0);
error = vfs_getopt(opts, "linux.osname", (void **)&osname, &len);
if (error != ENOENT) {
if (error != 0)
return (error);
if (len == 0 || osname[len - 1] != '\0')
return (EINVAL);
if (len > LINUX_MAX_UTSNAME) {
vfs_opterror(opts, "linux.osname too long");
return (ENAMETOOLONG);
}
}
error = vfs_getopt(opts, "linux.osrelease", (void **)&osrelease, &len);
if (error != ENOENT) {
if (error != 0)
return (error);
if (len == 0 || osrelease[len - 1] != '\0')
return (EINVAL);
if (len > LINUX_MAX_UTSNAME) {
vfs_opterror(opts, "linux.osrelease too long");
return (ENAMETOOLONG);
}
}
error = vfs_copyopt(opts, "linux.oss_version", &oss_version,
sizeof(oss_version));
return (error == ENOENT ? 0 : error);
}
static int
linux_prison_set(void *obj, void *data)
{
struct linux_prison *lpr;
struct prison *pr = obj;
struct vfsoptlist *opts = data;
char *osname, *osrelease;
size_t len;
int error, gotversion, nolinux, oss_version, yeslinux;
/* Set the parameters, which should be correct. */
yeslinux = vfs_flagopt(opts, "linux", NULL, 0);
nolinux = vfs_flagopt(opts, "nolinux", NULL, 0);
error = vfs_getopt(opts, "linux.osname", (void **)&osname, &len);
if (error == ENOENT)
osname = NULL;
else
yeslinux = 1;
error = vfs_getopt(opts, "linux.osrelease", (void **)&osrelease, &len);
if (error == ENOENT)
osrelease = NULL;
else
yeslinux = 1;
error = vfs_copyopt(opts, "linux.oss_version", &oss_version,
sizeof(oss_version));
gotversion = error == 0;
yeslinux |= gotversion;
if (nolinux) {
/* "nolinux": inherit the parent's Linux info. */
mtx_lock(&pr->pr_mtx);
osd_jail_del(pr, linux_osd_jail_slot);
mtx_unlock(&pr->pr_mtx);
} else if (yeslinux) {
/*
* "linux" or "linux.*":
* the prison gets its own Linux info.
*/
mtx_lock(&pr->pr_mtx);
error = linux_alloc_prison(pr, &lpr);
if (error) {
mtx_unlock(&pr->pr_mtx);
return (error);
}
if (osname)
strlcpy(lpr->pr_osname, osname, LINUX_MAX_UTSNAME);
if (osrelease) {
strlcpy(lpr->pr_osrelease, osrelease,
LINUX_MAX_UTSNAME);
lpr->pr_use_linux26 = strlen(osrelease) >= 3 &&
osrelease[2] == '6';
}
if (gotversion)
lpr->pr_oss_version = oss_version;
mtx_unlock(&pr->pr_mtx);
}
return (0);
}
SYSCTL_JAIL_PARAM_NODE(linux, "Jail Linux parameters");
SYSCTL_JAIL_PARAM(, nolinux, CTLTYPE_INT | CTLFLAG_RW,
"BN", "Jail w/ no Linux parameters");
SYSCTL_JAIL_PARAM_STRING(_linux, osname, CTLFLAG_RW, LINUX_MAX_UTSNAME,
"Jail Linux kernel OS name");
SYSCTL_JAIL_PARAM_STRING(_linux, osrelease, CTLFLAG_RW, LINUX_MAX_UTSNAME,
"Jail Linux kernel OS release");
SYSCTL_JAIL_PARAM(_linux, oss_version, CTLTYPE_INT | CTLFLAG_RW,
"I", "Jail Linux OSS version");
static int
linux_prison_get(void *obj, void *data)
{
struct linux_prison *lpr;
struct prison *pr = obj;
struct vfsoptlist *opts = data;
int error, i;
mtx_lock(&pr->pr_mtx);
/* Tell whether this prison has its own Linux info. */
lpr = osd_jail_get(pr, linux_osd_jail_slot);
i = lpr != NULL;
error = vfs_setopt(opts, "linux", &i, sizeof(i));
if (error != 0 && error != ENOENT)
goto done;
i = !i;
error = vfs_setopt(opts, "nolinux", &i, sizeof(i));
if (error != 0 && error != ENOENT)
goto done;
/*
* It's kind of bogus to give the root info, but leave it to the caller
* to check the above flag.
*/
if (lpr != NULL) {
error = vfs_setopts(opts, "linux.osname", lpr->pr_osname);
if (error != 0 && error != ENOENT)
goto done;
error = vfs_setopts(opts, "linux.osrelease", lpr->pr_osrelease);
if (error != 0 && error != ENOENT)
goto done;
error = vfs_setopt(opts, "linux.oss_version",
&lpr->pr_oss_version, sizeof(lpr->pr_oss_version));
if (error != 0 && error != ENOENT)
goto done;
} else {
mtx_lock(&osname_lock);
error = vfs_setopts(opts, "linux.osname", linux_osname);
if (error != 0 && error != ENOENT)
goto done;
error = vfs_setopts(opts, "linux.osrelease", linux_osrelease);
if (error != 0 && error != ENOENT)
goto done;
error = vfs_setopt(opts, "linux.oss_version",
&linux_oss_version, sizeof(linux_oss_version));
if (error != 0 && error != ENOENT)
goto done;
mtx_unlock(&osname_lock);
}
error = 0;
done:
mtx_unlock(&pr->pr_mtx);
return (error);
}
static void
linux_prison_destructor(void *data)
{
free(data, M_PRISON);
}
void
linux_osd_jail_register(void)
{
struct prison *pr;
osd_method_t methods[PR_MAXMETHOD] = {
[PR_METHOD_CREATE] = linux_prison_create,
[PR_METHOD_GET] = linux_prison_get,
[PR_METHOD_SET] = linux_prison_set,
[PR_METHOD_CHECK] = linux_prison_check
};
linux_osd_jail_slot =
osd_jail_register(linux_prison_destructor, methods);
if (linux_osd_jail_slot > 0) {
/* Copy the system linux info to any current prisons. */
sx_xlock(&allprison_lock);
TAILQ_FOREACH(pr, &allprison, pr_list) {
mtx_lock(&pr->pr_mtx);
(void)linux_alloc_prison(pr, NULL);
mtx_unlock(&pr->pr_mtx);
}
sx_xunlock(&allprison_lock);
}
}
void
linux_osd_jail_deregister(void)
{
if (linux_osd_jail_slot)
osd_jail_deregister(linux_osd_jail_slot);
}
void
linux_get_osname(struct thread *td, char *dst)
{
struct prison *pr;
struct linux_prison *lpr;
lpr = linux_get_prison(td, &pr);
if (lpr != NULL) {
bcopy(lpr->pr_osname, dst, LINUX_MAX_UTSNAME);
mtx_unlock(&pr->pr_mtx);
} else {
mtx_lock(&osname_lock);
bcopy(linux_osname, dst, LINUX_MAX_UTSNAME);
mtx_unlock(&osname_lock);
}
}
int
linux_set_osname(struct thread *td, char *osname)
{
struct prison *pr;
struct linux_prison *lpr;
lpr = linux_get_prison(td, &pr);
if (lpr != NULL) {
strlcpy(lpr->pr_osname, osname, LINUX_MAX_UTSNAME);
mtx_unlock(&pr->pr_mtx);
} else {
mtx_lock(&osname_lock);
strcpy(linux_osname, osname);
mtx_unlock(&osname_lock);
}
return (0);
}
void
linux_get_osrelease(struct thread *td, char *dst)
{
struct prison *pr;
struct linux_prison *lpr;
lpr = linux_get_prison(td, &pr);
if (lpr != NULL) {
bcopy(lpr->pr_osrelease, dst, LINUX_MAX_UTSNAME);
mtx_unlock(&pr->pr_mtx);
} else {
mtx_lock(&osname_lock);
bcopy(linux_osrelease, dst, LINUX_MAX_UTSNAME);
mtx_unlock(&osname_lock);
}
}
int
linux_use26(struct thread *td)
{
struct prison *pr;
struct linux_prison *lpr;
int use26;
lpr = linux_get_prison(td, &pr);
if (lpr != NULL) {
use26 = lpr->pr_use_linux26;
mtx_unlock(&pr->pr_mtx);
} else
use26 = linux_use_linux26;
return (use26);
}
int
linux_set_osrelease(struct thread *td, char *osrelease)
{
struct prison *pr;
struct linux_prison *lpr;
lpr = linux_get_prison(td, &pr);
if (lpr != NULL) {
strlcpy(lpr->pr_osrelease, osrelease, LINUX_MAX_UTSNAME);
lpr->pr_use_linux26 =
strlen(osrelease) >= 3 && osrelease[2] == '6';
mtx_unlock(&pr->pr_mtx);
} else {
mtx_lock(&osname_lock);
strcpy(linux_osrelease, osrelease);
linux_use_linux26 =
strlen(osrelease) >= 3 && osrelease[2] == '6';
mtx_unlock(&osname_lock);
}
return (0);
}
int
linux_get_oss_version(struct thread *td)
{
struct prison *pr;
struct linux_prison *lpr;
int version;
lpr = linux_get_prison(td, &pr);
if (lpr != NULL) {
version = lpr->pr_oss_version;
mtx_unlock(&pr->pr_mtx);
} else
version = linux_oss_version;
return (version);
}
int
linux_set_oss_version(struct thread *td, int oss_version)
{
struct prison *pr;
struct linux_prison *lpr;
lpr = linux_get_prison(td, &pr);
if (lpr != NULL) {
lpr->pr_oss_version = oss_version;
mtx_unlock(&pr->pr_mtx);
} else {
mtx_lock(&osname_lock);
linux_oss_version = oss_version;
mtx_unlock(&osname_lock);
}
return (0);
}
#if defined(DEBUG) || defined(KTR)
u_char linux_debug_map[howmany(LINUX_SYS_MAXSYSCALL, sizeof(u_char))];
static int
linux_debug(int syscall, int toggle, int global)
{
if (global) {
char c = toggle ? 0 : 0xff;
memset(linux_debug_map, c, sizeof(linux_debug_map));
return (0);
}
if (syscall < 0 || syscall >= LINUX_SYS_MAXSYSCALL)
return (EINVAL);
if (toggle)
clrbit(linux_debug_map, syscall);
else
setbit(linux_debug_map, syscall);
return (0);
}
/*
* Usage: sysctl linux.debug=<syscall_nr>.<0/1>
*
* E.g.: sysctl linux.debug=21.0
*
* As a special case, syscall "all" will apply to all syscalls globally.
*/
#define LINUX_MAX_DEBUGSTR 16
static int
linux_sysctl_debug(SYSCTL_HANDLER_ARGS)
{
char value[LINUX_MAX_DEBUGSTR], *p;
int error, sysc, toggle;
int global = 0;
value[0] = '\0';
error = sysctl_handle_string(oidp, value, LINUX_MAX_DEBUGSTR, req);
if (error || req->newptr == NULL)
return (error);
for (p = value; *p != '\0' && *p != '.'; p++);
if (*p == '\0')
return (EINVAL);
*p++ = '\0';
sysc = strtol(value, NULL, 0);
toggle = strtol(p, NULL, 0);
if (strcmp(value, "all") == 0)
global = 1;
error = linux_debug(sysc, toggle, global);
return (error);
}
SYSCTL_PROC(_compat_linux, OID_AUTO, debug,
CTLTYPE_STRING | CTLFLAG_RW,
0, 0, linux_sysctl_debug, "A",
"Linux debugging control");
#endif /* DEBUG || KTR */