r0 = socket$inet6_udp(0xa, 0x2, 0x0) setsockopt$inet6_int(r0, 0x29, 0x21, &(0x7f0000000080)=0x519, 0x4) sendmmsg$inet6(r0, &(0x7f0000000a00)=[{{&(0x7f0000000040)={0xa, 0x4e22, 0x0, @mcast2}, 0x1c, 0x0}}], 0x1, 0x0)