Socket descriptors are eligible for fstat(), so sockets can be called for vn_getattr. The PFS should consider supporting this operation and returning some information in the ATTR structure. At a minimum, you could return: the file type, permission bits of 777, the current time for the time values, the devno as passed by vfs_network, and an inode number for the socket that is unique for this socket at this point in time.

Generally, a program cannot set any attributes of a socket, so the PFS does not have to support the vn_setattr operation.