The `datalen` indicates the whole len of original packet, which will become the payload inside icmpv6 packet.
Using `datalen = (ipv4->len[0] << 8) + ipv4->len[1]` in icmp_reply is correct, because it includes IPv4 header, but when coming to IPv6, the `len` does not include the header, so we need to add it back.
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
commit 3b69d09c80 corrected the
unreachable handling for net/udp/icmp but introduced an unaligned store.
This splits the uint32_t data field into a two element uint16_t data
field to avoid the unaligned store.
Reference RFC1122:
https://datatracker.ietf.org/doc/html/rfc1122
----------------------------------------------
4.1.3 SPECIFIC ISSUES
4.1.3.1 Ports
If a datagram arrives addressed to a UDP port for which
there is no pending LISTEN call, UDP SHOULD send an ICMP
Port Unreachable message.
Signed-off-by: chao.an <anchao@xiaomi.com>
