Parse received addrv2 messages

[teor2345]

Motivation

ZIP-155 activates at the same time as NU5 on mainnet.

To implement this ZIP, Zebra needs to parse received addrv2 messages.
Sending addrv2 messages is out of scope.

Specifications

https://zips.z.cash/zip-0155#specification

Solution

• add an AddrV2 type for parsing addrv2 messages
• update the message decoder to use AddrV2 for parsing addrv2 messages
• limit addr and addrv2 messages to MAX_ADDRS_IN_MESSAGE
  • this is a bug fix for received addr messages
• add tests for AddrV2

Closes #2681.

Review

I'd like both @jvff and @oxarbitrage to review this change, because it's the riskiest part of the ticket.

This is the last in the series of addrv2 PRs. This PR is based on PR #3032.

Reviewer Checklist

• Code implements Specs and Designs
• Tests for Expected Behaviour
• Tests for Errors

Follow Up Work

We should try to get some test vectors from the zcashd team.

[jvff]

Looks great! I added two suggestions, but they're optional.

[zancas]

OK, I've added a few tests to a zcashd feature branch. The test vectors are composed of addresses and serializations that were already in the tests elsewhere, but they are conveniently adjacent here:

https://github.com/zingolabs/zcash/blob/9ee66e423a3fbf4829ffeec354e82f4fbceff864/src/test/netbase_tests.cpp#L481

[jvff]

Overall looks good. There's one documentation typo, and I also added some optional suggestions.

[teor2345]

I'm going to put this in draft until I add test vectors from zcashd, and test vectors with extreme service values and address lengths.

[teor2345]

OK, I've added a few tests to a zcashd feature branch. The test vectors are composed of addresses and serializations that were already in the tests elsewhere, but they are conveniently adjacent here:

https://github.com/zingolabs/zcash/blob/9ee66e423a3fbf4829ffeec354e82f4fbceff864/src/test/netbase_tests.cpp#L481

@zancas thanks, we're now testing these cases in Zebra as well.

I added some extra addrv1 and addrv2 cases to cover various parsing edge-cases.
You can see them at:

zebra/zebra-test/src/network_addr.rs

Line 46 in f246cbc

// Extra test cases:

zebra/zebra-test/src/network_addr.rs

Line 122 in f246cbc

// Extra test cases:

Our test implementation is here, but it's probably not that interesting for you:

zebra/zebra-network/src/protocol/external/tests/vectors.rs

Line 39 in f246cbc

/// Test that deserializing [`AddrV1`] into [`MetaAddr`] succeeds,

[jvff]

Looks good! I added a few suggestions, but they are all optional 👍

[teor2345]

I applied the optional suggestions.

@zancas commit a7f11c2 fixes a mistake in the comments about the Tor v3 address test vectors. (I also listed all the field values in those comments.)