10. sftp: Extension request "hardlink@openssh.com"
This request is for creating a hard link to a regular file. This
request is implemented as a SSH_FXP_EXTENDED request with the
following format:
uint32 id
string "hardlink@openssh.com"
string oldpath
string newpath
On receiving this request the server will perform the operation
link(oldpath, newpath) and will respond with a SSH_FXP_STATUS message.
This extension is advertised in the SSH_FXP_VERSION hello with version
"1".
Title.
A quick google landed me on this: