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authorVenkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>2010-06-14 13:34:45 -0700
committerAnthony Liguori <aliguori@us.ibm.com>2010-06-22 15:15:50 -0500
commit4750a96f6baf8949cc04a0c5b7167606544a4401 (patch)
tree59dfed5f2adfb3fb546c078119629e3eca599d82 /hw
parent1237ad7607aae5859067831e36a59d3b017c5a54 (diff)
virtio-9p: Security model for create/open2
In the mapped security model, VirtFS server intercepts and maps the file object create and get/set attribute requests. Files on the fileserver will be created with VirtFS servers (QEMU) user credentials and the client-users credentials are stored in extended attributes. On the request to get attributes, server extracts the client-users credentials from extended attributes and sends them to the client. On Host/Fileserver: -rw-------. 2 virfsuid virtfsgid 0 2010-05-11 09:19 afile On Guest/Client: -rw-r--r-- 2 guestuser guestuser 0 2010-05-11 12:19 afile Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/file-op-9p.h2
-rw-r--r--hw/virtio-9p-local.c51
-rw-r--r--hw/virtio-9p.c16
3 files changed, 61 insertions, 8 deletions
diff --git a/hw/file-op-9p.h b/hw/file-op-9p.h
index a53cd35094..b345189336 100644
--- a/hw/file-op-9p.h
+++ b/hw/file-op-9p.h
@@ -62,7 +62,7 @@ typedef struct FileOperations
int (*closedir)(FsContext *, DIR *);
DIR *(*opendir)(FsContext *, const char *);
int (*open)(FsContext *, const char *, int);
- int (*open2)(FsContext *, const char *, int, mode_t);
+ int (*open2)(FsContext *, const char *, int, FsCred *);
void (*rewinddir)(FsContext *, DIR *);
off_t (*telldir)(FsContext *, DIR *);
struct dirent *(*readdir)(FsContext *, DIR *);
diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
index 74c81a60dc..bb5140efce 100644
--- a/hw/virtio-9p-local.c
+++ b/hw/virtio-9p-local.c
@@ -95,6 +95,18 @@ static int local_set_xattr(const char *path, FsCred *credp)
return 0;
}
+static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
+ FsCred *credp)
+{
+ if (chmod(rpath(fs_ctx, path), credp->fc_mode & 07777) < 0) {
+ return -1;
+ }
+ if (chown(rpath(fs_ctx, path), credp->fc_uid, credp->fc_gid) < 0) {
+ return -1;
+ }
+ return 0;
+}
+
static ssize_t local_readlink(FsContext *ctx, const char *path,
char *buf, size_t bufsz)
{
@@ -230,9 +242,44 @@ static int local_fstat(FsContext *fs_ctx, int fd, struct stat *stbuf)
return err;
}
-static int local_open2(FsContext *ctx, const char *path, int flags, mode_t mode)
+static int local_open2(FsContext *fs_ctx, const char *path, int flags,
+ FsCred *credp)
{
- return open(rpath(ctx, path), flags, mode);
+ int fd = -1;
+ int err = -1;
+ int serrno = 0;
+
+ /* Determine the security model */
+ if (fs_ctx->fs_sm == SM_MAPPED) {
+ fd = open(rpath(fs_ctx, path), flags, SM_LOCAL_MODE_BITS);
+ if (fd == -1) {
+ return fd;
+ }
+ credp->fc_mode = credp->fc_mode|S_IFREG;
+ /* Set cleint credentials in xattr */
+ err = local_set_xattr(rpath(fs_ctx, path), credp);
+ if (err == -1) {
+ serrno = errno;
+ goto err_end;
+ }
+ } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
+ fd = open(rpath(fs_ctx, path), flags, credp->fc_mode);
+ if (fd == -1) {
+ return fd;
+ }
+ err = local_post_create_passthrough(fs_ctx, path, credp);
+ if (err == -1) {
+ serrno = errno;
+ goto err_end;
+ }
+ }
+ return fd;
+
+err_end:
+ close(fd);
+ remove(rpath(fs_ctx, path));
+ errno = serrno;
+ return err;
}
diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index fa459c9260..49a3065be9 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -180,9 +180,17 @@ static int v9fs_do_fstat(V9fsState *s, int fd, struct stat *stbuf)
return s->ops->fstat(&s->ctx, fd, stbuf);
}
-static int v9fs_do_open2(V9fsState *s, V9fsString *path, int flags, mode_t mode)
+static int v9fs_do_open2(V9fsState *s, V9fsCreateState *vs)
{
- return s->ops->open2(&s->ctx, path->data, flags, mode);
+ FsCred cred;
+ int flags;
+
+ cred_init(&cred);
+ cred.fc_uid = vs->fidp->uid;
+ cred.fc_mode = vs->perm & 0777;
+ flags = omode_to_uflags(vs->mode) | O_CREAT;
+
+ return s->ops->open2(&s->ctx, vs->fullname.data, flags, &cred);
}
static int v9fs_do_symlink(V9fsState *s, V9fsString *oldpath,
@@ -1815,9 +1823,7 @@ static void v9fs_create_post_lstat(V9fsState *s, V9fsCreateState *vs, int err)
err = v9fs_do_mksock(s, &vs->fullname);
v9fs_create_post_mksock(s, vs, err);
} else {
- vs->fidp->fd = v9fs_do_open2(s, &vs->fullname,
- omode_to_uflags(vs->mode) | O_CREAT,
- vs->perm & 0777);
+ vs->fidp->fd = v9fs_do_open2(s, vs);
v9fs_create_post_open2(s, vs, err);
}