r0 = socket$inet6_tcp(0xa, 0x1, 0x0)
setsockopt$inet6_tcp_TCP_FASTOPEN_KEY(r0, 0x6, 0x21, &(0x7f0000000300)="e3ea646bdd7dca35511961866df8b71b", 0x10)
getsockopt$inet6_tcp_buf(r0, 0x6, 0x21, 0x0, &(0x7f0000000180))