virtio-9p: Make infrastructure for the new security model.

This patch adds required infrastructure for the new security model.

- A new configure option for attr/xattr.
- if CONFIG_VIRTFS will be defined if both CONFIG_LINUX and CONFIG_ATTR defined.
- Defines routines related to both security models.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Venkateswararao Jujjuri (JV) 2010-06-14 13:34:41 -07:00 committed by Anthony Liguori
parent 9ce56db6f0
commit 758e8e38eb
8 changed files with 114 additions and 53 deletions

View File

@ -35,8 +35,8 @@ net-nested-$(CONFIG_SLIRP) += slirp.o
net-nested-$(CONFIG_VDE) += vde.o
net-obj-y += $(addprefix net/, $(net-nested-y))
fsdev-nested-$(CONFIG_LINUX) = qemu-fsdev.o
fsdev-obj-$(CONFIG_LINUX) += $(addprefix fsdev/, $(fsdev-nested-y))
fsdev-nested-$(CONFIG_VIRTFS) = qemu-fsdev.o
fsdev-obj-$(CONFIG_VIRTFS) += $(addprefix fsdev/, $(fsdev-nested-y))
######################################################################
# libqemu_common.a: Target independent part of system emulation. The
@ -233,7 +233,7 @@ sound-obj-$(CONFIG_CS4231A) += cs4231a.o
adlib.o fmopl.o: QEMU_CFLAGS += -DBUILD_Y8950=0
hw-obj-$(CONFIG_SOUND) += $(sound-obj-y)
hw-obj-$(CONFIG_LINUX) += virtio-9p-debug.o virtio-9p-local.o
hw-obj-$(CONFIG_VIRTFS) += virtio-9p-debug.o virtio-9p-local.o
######################################################################
# libdis

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@ -169,7 +169,7 @@ obj-y += virtio-blk.o virtio-balloon.o virtio-net.o virtio-serial-bus.o
obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
obj-y += vhost_net.o
obj-$(CONFIG_VHOST_NET) += vhost.o
obj-$(CONFIG_LINUX) += virtio-9p.o
obj-$(CONFIG_VIRTFS) += virtio-9p.o
obj-y += rwhandler.o
obj-$(CONFIG_KVM) += kvm.o kvm-all.o
obj-$(CONFIG_NO_KVM) += kvm-stub.o

37
configure vendored
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@ -270,6 +270,7 @@ vnc_tls=""
vnc_sasl=""
xen=""
linux_aio=""
attr=""
vhost_net=""
gprof="no"
@ -671,6 +672,10 @@ for opt do
;;
--enable-linux-aio) linux_aio="yes"
;;
--disable-attr) attr="no"
;;
--enable-attr) attr="yes"
;;
--enable-io-thread) io_thread="yes"
;;
--disable-blobs) blobs="no"
@ -858,6 +863,8 @@ echo " --disable-vde disable support for vde network"
echo " --enable-vde enable support for vde network"
echo " --disable-linux-aio disable Linux AIO support"
echo " --enable-linux-aio enable Linux AIO support"
echo " --disable-attr disables attr and xattr support"
echo " --enable-attr enable attr and xattr support"
echo " --enable-io-thread enable IO thread"
echo " --disable-blobs disable installing provided firmware blobs"
echo " --kerneldir=PATH look for kernel includes in PATH"
@ -1645,6 +1652,27 @@ EOF
fi
fi
##########################################
# attr probe
if test "$attr" != "no" ; then
cat > $TMPC <<EOF
#include <stdio.h>
#include <sys/types.h>
#include <attr/xattr.h>
int main(void) { getxattr(NULL, NULL, NULL, 0); setxattr(NULL, NULL, NULL, 0, 0); return 0; }
EOF
if compile_prog "" "-lattr" ; then
attr=yes
LIBS="-lattr $LIBS"
else
if test "$attr" = "yes" ; then
feature_not_found "ATTR"
fi
attr=no
fi
fi
##########################################
# iovec probe
cat > $TMPC <<EOF
@ -2079,6 +2107,7 @@ echo "PIE user targets $user_pie"
echo "vde support $vde"
echo "IO thread $io_thread"
echo "Linux AIO support $linux_aio"
echo "ATTR/XATTR support $attr"
echo "Install blobs $blobs"
echo "KVM support $kvm"
echo "fdt support $fdt"
@ -2280,6 +2309,14 @@ fi
if test "$linux_aio" = "yes" ; then
echo "CONFIG_LINUX_AIO=y" >> $config_host_mak
fi
if test "$attr" = "yes" ; then
echo "CONFIG_ATTR=y" >> $config_host_mak
fi
if test "$linux" = "yes" ; then
if test "$attr" = "yes" ; then
echo "CONFIG_VIRTFS=y" >> $config_host_mak
fi
fi
if test "$blobs" = "yes" ; then
echo "INSTALL_BLOBS=yes" >> $config_host_mak
fi

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@ -18,13 +18,33 @@
#include <utime.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/vfs.h>
#define SM_LOCAL_MODE_BITS 0600
#define SM_LOCAL_DIR_MODE_BITS 0700
typedef enum
{
SM_PASSTHROUGH = 1, /* uid/gid set on fileserver files */
SM_MAPPED, /* uid/gid part of xattr */
} SecModel;
typedef struct FsCred
{
uid_t fc_uid;
gid_t fc_gid;
mode_t fc_mode;
dev_t fc_rdev;
} FsCred;
typedef struct FsContext
{
char *fs_root;
SecModel fs_sm;
uid_t uid;
} FsContext;
extern void cred_init(FsCred *);
typedef struct FileOperations
{
int (*lstat)(FsContext *, const char *, struct stat *);

View File

@ -17,6 +17,7 @@
#include <grp.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <attr/xattr.h>
static const char *rpath(FsContext *ctx, const char *path)
{
@ -31,45 +32,37 @@ static int local_lstat(FsContext *ctx, const char *path, struct stat *stbuf)
return lstat(rpath(ctx, path), stbuf);
}
static int local_setuid(FsContext *ctx, uid_t uid)
static int local_set_xattr(const char *path, FsCred *credp)
{
struct passwd *pw;
gid_t groups[33];
int ngroups;
static uid_t cur_uid = -1;
if (cur_uid == uid) {
return 0;
int err;
if (credp->fc_uid != -1) {
err = setxattr(path, "user.virtfs.uid", &credp->fc_uid, sizeof(uid_t),
0);
if (err) {
return err;
}
}
if (setreuid(0, 0)) {
return -1;
if (credp->fc_gid != -1) {
err = setxattr(path, "user.virtfs.gid", &credp->fc_gid, sizeof(gid_t),
0);
if (err) {
return err;
}
}
pw = getpwuid(uid);
if (pw == NULL) {
return -1;
if (credp->fc_mode != -1) {
err = setxattr(path, "user.virtfs.mode", &credp->fc_mode,
sizeof(mode_t), 0);
if (err) {
return err;
}
}
ngroups = 33;
if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1) {
return -1;
if (credp->fc_rdev != -1) {
err = setxattr(path, "user.virtfs.rdev", &credp->fc_rdev,
sizeof(dev_t), 0);
if (err) {
return err;
}
}
if (setgroups(ngroups, groups)) {
return -1;
}
if (setregid(-1, pw->pw_gid)) {
return -1;
}
if (setreuid(-1, uid)) {
return -1;
}
cur_uid = uid;
return 0;
}
@ -183,6 +176,7 @@ static int local_open2(FsContext *ctx, const char *path, int flags, mode_t mode)
return open(rpath(ctx, path), flags, mode);
}
static int local_symlink(FsContext *ctx, const char *oldpath,
const char *newpath)
{
@ -259,12 +253,13 @@ static int local_remove(FsContext *ctx, const char *path)
static int local_fsync(FsContext *ctx, int fd)
{
if (0) /* Just to supress the warning. Will be removed in next patch. */
(void)local_set_xattr(NULL, NULL);
return fsync(fd);
}
FileOperations local_ops = {
.lstat = local_lstat,
.setuid = local_setuid,
.readlink = local_readlink,
.close = local_close,
.closedir = local_closedir,

View File

@ -67,16 +67,19 @@ static int omode_to_uflags(int8_t mode)
return ret;
}
void cred_init(FsCred *credp)
{
credp->fc_uid = -1;
credp->fc_gid = -1;
credp->fc_mode = -1;
credp->fc_rdev = -1;
}
static int v9fs_do_lstat(V9fsState *s, V9fsString *path, struct stat *stbuf)
{
return s->ops->lstat(&s->ctx, path->data, stbuf);
}
static int v9fs_do_setuid(V9fsState *s, uid_t uid)
{
return s->ops->setuid(&s->ctx, uid);
}
static ssize_t v9fs_do_readlink(V9fsState *s, V9fsString *path, V9fsString *buf)
{
ssize_t len;
@ -348,7 +351,6 @@ static V9fsFidState *lookup_fid(V9fsState *s, int32_t fid)
for (f = s->fid_list; f; f = f->next) {
if (f->fid == fid) {
v9fs_do_setuid(s, f->uid);
return f;
}
}
@ -2253,8 +2255,15 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
exit(1);
}
if (!strcmp(fse->security_model, "passthrough") &&
!strcmp(fse->security_model, "mapped")) {
if (!strcmp(fse->security_model, "passthrough")) {
/* Files on the Fileserver set to client user credentials */
s->ctx.fs_sm = SM_PASSTHROUGH;
} else if (!strcmp(fse->security_model, "mapped")) {
/* Files on the fileserver are set to QEMU credentials.
* Client user credentials are saved in extended attributes.
*/
s->ctx.fs_sm = SM_MAPPED;
} else {
/* user haven't specified a correct security option */
fprintf(stderr, "one of the following must be specified as the"
"security option:\n\t security_model=passthrough \n\t "

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@ -641,7 +641,7 @@ static int virtio_balloon_init_pci(PCIDevice *pci_dev)
return 0;
}
#ifdef CONFIG_LINUX
#ifdef CONFIG_VIRTFS
static int virtio_9p_init_pci(PCIDevice *pci_dev)
{
VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
@ -712,7 +712,7 @@ static PCIDeviceInfo virtio_info[] = {
},
.qdev.reset = virtio_pci_reset,
},{
#ifdef CONFIG_LINUX
#ifdef CONFIG_VIRTFS
.qdev.name = "virtio-9p-pci",
.qdev.size = sizeof(VirtIOPCIProxy),
.init = virtio_9p_init_pci,

8
vl.c
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@ -147,7 +147,7 @@ int main(int argc, char **argv)
#include "qemu-config.h"
#include "qemu-objects.h"
#include "qemu-options.h"
#ifdef CONFIG_LINUX
#ifdef CONFIG_VIRTFS
#include "fsdev/qemu-fsdev.h"
#endif
@ -1532,7 +1532,7 @@ static int chardev_init_func(QemuOpts *opts, void *opaque)
return 0;
}
#ifdef CONFIG_LINUX
#ifdef CONFIG_VIRTFS
static int fsdev_init_func(QemuOpts *opts, void *opaque)
{
int ret;
@ -2281,7 +2281,7 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
break;
#ifdef CONFIG_LINUX
#ifdef CONFIG_VIRTFS
case QEMU_OPTION_fsdev:
opts = qemu_opts_parse(&qemu_fsdev_opts, optarg, 1);
if (!opts) {
@ -2705,7 +2705,7 @@ int main(int argc, char **argv, char **envp)
if (qemu_opts_foreach(&qemu_chardev_opts, chardev_init_func, NULL, 1) != 0)
exit(1);
#ifdef CONFIG_LINUX
#ifdef CONFIG_VIRTFS
if (qemu_opts_foreach(&qemu_fsdev_opts, fsdev_init_func, NULL, 1) != 0) {
exit(1);
}