Defined in 2 files as a macro:

• include/uapi/linux/if_tun.h, line 48 (as a macro)
• tools/include/uapi/linux/if_tun.h, line 48 (as a macro)

Referenced in 4 files:

• arch/um/drivers/vector_user.c, line 597
• drivers/net/tun_vnet.h, line 77
• tools/testing/selftests/net/tun.c, line 197
• tools/virtio/vhost_net_test.c, line 84