Function encode_icmp_error 

pub fn encode_icmp_error(
    invoking: IpPacket<'_>,
    source: IpAddr,
    kind: IcmpErrorKind,
    output: &mut [u8],
) -> Result<Option<usize>, IpPacketError>

Available on crate feature net only.

Encode an IP packet carrying an ICMP error and a bounded quotation of invoking.

Returns None when error generation is suppressed: an error in response to an error, an unusable source, a non-initial IPv4 fragment, or a multicast destination (except IPv6 Packet Too Big). The caller must also suppress errors for link-layer broadcasts and subnet-directed IPv4 broadcasts, which cannot be identified without link configuration, and apply a rate limit.

Replies are at most 576 bytes for IPv4 and 1280 for IPv6; they do not reflect arbitrary peer-sized payloads. source is an address selected by the caller’s routing policy, not automatically the invoking packet’s destination.