virtio-9p: Implement Security model for mknod

Mapped mode stores extended attributes in the user space of the extended
attributes. Given that the user space extended attributes are available
to regular files only, special files are created as regular files on the
fileserver and appropriate mode bits are added to the extended attributes.
This method presents all special files and symlinks as regular files on the
fileserver while they are represented as special files on the guest mount.

On Host/Fileserver:
-rw-------. 1 virfsuid virtfsgid 0 2010-05-11 09:36 afifo
-rw-------. 1 virfsuid virtfsgid 0 2010-05-11 09:32 blkdev
-rw-------. 1 virfsuid virtfsgid 0 2010-05-11 09:33 chardev

On Guest/Client:
prw-r--r-- 1 guestuser guestuser 0 2010-05-11 12:36 afifo
brw-r--r-- 1 guestuser guestuser 0, 0 2010-05-11 12:32 blkdev
crw-r--r-- 1 guestuser guestuser 4, 5 2010-05-11 12:33 chardev

In the passthrough securit model, specifal files are directly created
on the fileserver. But the user credential

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/hw/file-op-9p.h b/hw/file-op-9p.h
index 0808630fe4b74646a76f4b54e0138d82ceed1e87..5bc61b5dc1d57cac445b662f74fde6975e32aa88 100644 (file)
--- a/hw/file-op-9p.h
+++ b/hw/file-op-9p.h
@@ -51,7 +51,7 @@ typedef struct FileOperations
     ssize_t (*readlink)(FsContext *, const char *, char *, size_t);
     int (*chmod)(FsContext *, const char *, FsCred *);
     int (*chown)(FsContext *, const char *, FsCred *);
-    int (*mknod)(FsContext *, const char *, mode_t, dev_t);
+    int (*mknod)(FsContext *, const char *, FsCred *);
     int (*mksock)(FsContext *, const char *);
     int (*utime)(FsContext *, const char *, const struct utimbuf *);
     int (*remove)(FsContext *, const char *);

diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
index 711f2b5ca1c77db11c2ca4848672ed0c37376dd8..791a8ba0880194c49b5815c0bdafbfd718a22517 100644 (file)
--- a/hw/virtio-9p-local.c
+++ b/hw/virtio-9p-local.c
@@ -195,9 +195,39 @@ static int local_chmod(FsContext *fs_ctx, const char *path, FsCred *credp)
     return -1;
 }
 
-static int local_mknod(FsContext *ctx, const char *path, mode_t mode, dev_t dev)
+static int local_mknod(FsContext *fs_ctx, const char *path, FsCred *credp)
 {
-    return mknod(rpath(ctx, path), mode, dev);
+    int err = -1;
+    int serrno = 0;
+
+    /* Determine the security model */
+    if (fs_ctx->fs_sm == SM_MAPPED) {
+        err = mknod(rpath(fs_ctx, path), SM_LOCAL_MODE_BITS|S_IFREG, 0);
+        if (err == -1) {
+            return 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) {
+        err = mknod(rpath(fs_ctx, path), credp->fc_mode, credp->fc_rdev);
+        if (err == -1) {
+            return err;
+        }
+        err = local_post_create_passthrough(fs_ctx, path, credp);
+        if (err == -1) {
+            serrno = errno;
+            goto err_end;
+        }
+    }
+    return err;
+
+err_end:
+    remove(rpath(fs_ctx, path));
+    errno = serrno;
+    return err;
 }
 
 static int local_mksock(FsContext *ctx2, const char *path)

diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index 1a25e9695568cc7b1a74a069f6fc494f395c38b7..d276db3762ff90fe383035c17ae89f514677e9dd 100644 (file)
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -160,9 +160,15 @@ static int v9fs_do_chmod(V9fsState *s, V9fsString *path, mode_t mode)
     return s->ops->chmod(&s->ctx, path->data, &cred);
 }
 
-static int v9fs_do_mknod(V9fsState *s, V9fsString *path, mode_t mode, dev_t dev)
+static int v9fs_do_mknod(V9fsState *s, V9fsCreateState *vs, mode_t mode,
+        dev_t dev)
 {
-    return s->ops->mknod(&s->ctx, path->data, mode, dev);
+    FsCred cred;
+    cred_init(&cred);
+    cred.fc_uid = vs->fidp->uid;
+    cred.fc_mode = mode;
+    cred.fc_rdev = dev;
+    return s->ops->mknod(&s->ctx, vs->fullname.data, &cred);
 }
 
 static int v9fs_do_mksock(V9fsState *s, V9fsString *path)
@@ -1825,10 +1831,10 @@ static void v9fs_create_post_lstat(V9fsState *s, V9fsCreateState *vs, int err)
         }
 
         nmode |= vs->perm & 0777;
-        err = v9fs_do_mknod(s, &vs->fullname, nmode, makedev(major, minor));
+        err = v9fs_do_mknod(s, vs, nmode, makedev(major, minor));
         v9fs_create_post_perms(s, vs, err);
     } else if (vs->perm & P9_STAT_MODE_NAMED_PIPE) {
-        err = v9fs_do_mknod(s, &vs->fullname, S_IFIFO | (vs->mode & 0777), 0);
+        err = v9fs_do_mknod(s, vs, S_IFIFO | (vs->perm & 0777), 0);
         v9fs_post_create(s, vs, err);
     } else if (vs->perm & P9_STAT_MODE_SOCKET) {
         err = v9fs_do_mksock(s, &vs->fullname);