r0 = socket$inet6_udp(0xa, 0x2, 0x0)
connect$inet6(r0, &(0x7f0000000000)={0xa, 0x0, 0x0, @mcast2, 0x5}, 0x1c)
sendmmsg$inet6(r0, &(0x7f0000004d00)=[{{0x0, 0x0, &(0x7f00000004c0)=[{&(0x7f0000000080)='K', 0x1}], 0x1}}], 0x7ffff000, 0x0)
setsockopt$inet6_IPV6_RTHDRDSTOPTS(r0, 0x29, 0x37, &(0x7f0000000300)=ANY=[], 0xb8)