rustc(E0515) when trying to use icmp_packet_iter.next()

Apologies if this is a Rust noob question.

I am trying to return the first reply packet from a Layer4(Ipv4(IpNextHeaderProtocols::Icmp)) transport_channel.

The end of my function is:

    let mut rx_iter = icmp_packet_iter(&mut rx);
    rx_iter.next()

And I get the following errors:

error[E0515]: cannot return reference to local variable `rx_iter`
  --> src\main.rs:29:5
   |
29 |     rx_iter.next()
   |     ^^^^^^^^^^^^^^ returns a reference to data owned by the current function

error[E0515]: cannot return value referencing local variable `rx`
  --> src\main.rs:29:5
   |
28 |     let mut rx_iter = icmp_packet_iter(&mut rx);
   |                                        ------- `rx` is borrowed here
29 |     rx_iter.next()
   |     ^^^^^^^^^^^^^^ returns a value referencing data owned by the current function

The official advice is to "consider returning an owned value instead". How should I do it?

Start in src/main.rs at the transport_channel setup and the icmp_packet_iter call, then check the iterator's return type and lifetime against Rust's E0515 guidance. Determine an owned return value that does not borrow local rx or rx_iter, and verify that it represents the first received ICMP reply.