  We show how to generate Bell states and $N$-partite $W$ states of
long-distance superconducting (SC) qubits in a SC waveguide quantum
electrodynamical (QED) system, where SC qubits are coupled to an open microwave
transmission line. In the two-qubit case, the Bell state of two long-distance
qubits can be a dark state of the system by choosing appropriate system
parameters. If one proper microwave pulse drives one of two qubits, the two
qubits will evolve from their ground states to a Bell state. Further, we extend
this scheme to the multi-qubit case. We show that $W$ states of $N$
long-distance qubits can also be generated. Because both the Bell and $W$
states are decoupled from the waveguide (i.e., dark states of the system), they
are steady and have very long lifetimes in the ideal case without decoherence
of qubits. In contrast to the ideal case, the presence of decoherence of qubits
limits the lifetimes of the Bell and $W$ states. Our study provides a novel
scheme for generating Bell states and $N$-partite $W$ states in SC waveguide
QED, which can be used to entangle long-distance nodes in waveguide quantum
networks.
