r0 = socket$inet6_udp(0xa, 0x2, 0x0)
setsockopt$inet6_IPV6_FLOWLABEL_MGR(r0, 0x29, 0x20, &(0x7f0000000040)={@loopback, 0x0, 0x0, 0x2, 0x1}, 0x21)
sendmsg$inet6(r0, &(0x7f00000005c0)={&(0x7f00000002c0)={0xa, 0x4e24, 0x0, @mcast2}, 0x1c, 0x0, 0x0, &(0x7f0000000540)=[@flowinfo={{0x14, 0x29, 0xb, 0xc8}}], 0x18}, 0x0)