tools/kvm/9p: Add error protocol reply

Add RERROR and use that in open on failure

NOTE: All the protocol operation should handle like this.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

diff --git a/tools/kvm/virtio/9p.c b/tools/kvm/virtio/9p.c
index d27017b4cb08ba4d522330d464dfb97738f61385..2015c543a3d65584edb51242c8869eac54d654af 100644 (file)
--- a/tools/kvm/virtio/9p.c
+++ b/tools/kvm/virtio/9p.c
@@ -210,6 +210,22 @@ static u16 virtio_p9_update_iov_cnt(struct iovec iov[], u32 count, int iov_cnt)
        return i;
 }
 
+static void virtio_p9_error_reply(struct p9_dev *p9dev,
+                                 struct p9_pdu *pdu, int err, u32 *outlen)
+{
+       char *err_str;
+       struct p9_msg *inmsg  = pdu->in_iov[0].iov_base;
+       struct p9_msg *outmsg = pdu->out_iov[0].iov_base;
+       struct p9_rerror *rerror  = (struct p9_rerror *)inmsg->msg;
+
+       err_str = strerror(err);
+       rerror->error.len = strlen(err_str);
+       memcpy(&rerror->error.str, err_str, rerror->error.len);
+
+       *outlen = VIRTIO_P9_HDR_LEN + rerror->error.len + sizeof(u16);
+       set_p9msg_hdr(inmsg, *outlen, P9_RERROR, outmsg->tag);
+}
+
 static bool virtio_p9_version(struct p9_dev *p9dev,
                              struct p9_pdu *pdu, u32 *outlen)
 {
@@ -254,19 +270,26 @@ static bool virtio_p9_open(struct p9_dev *p9dev,
        struct p9_fid *new_fid  = &p9dev->fids[topen->fid];
 
        if (lstat(new_fid->abs_path, &st) < 0)
-               return false;
+               goto err_out;
 
        st2qid(&st, &ropen->qid);
        ropen->iounit = 0;
 
-       if (new_fid->is_dir)
-               new_fid->dir    = opendir(new_fid->abs_path);
-       else
-               new_fid->fd     = open(new_fid->abs_path, omode2uflags(topen->mode));
-
+       if (new_fid->is_dir) {
+               new_fid->dir = opendir(new_fid->abs_path);
+               if (!new_fid->dir)
+                       goto err_out;
+       } else {
+               new_fid->fd  = open(new_fid->abs_path,
+                                  omode2uflags(topen->mode) | O_NOFOLLOW);
+               if (new_fid->fd < 0)
+                       goto err_out;
+       }
        *outlen = VIRTIO_P9_HDR_LEN + sizeof(*ropen);
        set_p9msg_hdr(inmsg, *outlen, P9_ROPEN, outmsg->tag);
-
+       return true;
+err_out:
+       virtio_p9_error_reply(p9dev, pdu, errno, outlen);
        return true;
 }