3004d5a [validation] Remove fMissingInputs from AcceptToMemoryPool() (John Newbery)
c428622 [validation] Remove unused first_invalid parameter from ProcessNewBlockHeaders() (John Newbery)
7204c64 [validation] Remove useless ret parameter from Invalid() (John Newbery)
1a37de4 [validation] Remove error() calls from Invalid() calls (John Newbery)
067981e [validation] Tidy Up ValidationResult class (John Newbery)
a27a295 [validation] Add CValidationState subclasses (John Newbery)

Pull request description:

  Carries out some remaining tidy-ups remaining after PR 15141:

  - split ValidationState into TxValidationState and BlockValidationState (commit from ajtowns)
  - various minor code style tidy-ups to the ValidationState class
  - remove the useless `ret` parameter from `ValidationState::Invalid()`
  - remove the now unused `first_invalid` parameter from `ProcessNewBlockHeaders()`
  - remove the `fMissingInputs` parameter from `AcceptToMemoryPool()`, and deal with missing inputs the same way as other errors by using the `TxValidationState` object.

  Tip for reviewers (thanks ryanofsky!): The first commit ("[validation] Add CValidationState subclasses" ) is huge and can be easier to start reviewing if you revert the rote, mechanical changes:

  Substitute the commit hash of commit "[validation] Add CValidationState subclasses" for <CommitHash> in the commands below.

  ```sh
  git checkout <CommitHash>
  git grep -l ValidationState | xargs sed -i 's/BlockValidationState\|TxValidationState/CValidationState/g'
  git grep -l ValidationResult | xargs sed -i 's/BlockValidationResult\|TxValidationResult/ValidationInvalidReason/g'
  git grep -l MaybePunish | xargs sed -i 's/MaybePunishNode\(ForBlock\|ForTx\)/MaybePunishNode/g'
  git diff HEAD^
  ```

  After that it's possible to easily see the mechanical changes with:

  ```sh
  git log -p -n1 -U0 --word-diff-regex=. <CommitHash>
  ```

ACKs for top commit:
  laanwj:
    ACK 3004d5a
  amitiuttarwar:
    code review ACK 3004d5a. Also built & ran tests locally.
  fjahr:
    Code review ACK 3004d5a . Only nit style change and pure virtual destructor added since my last review.
  ryanofsky:
    Code review ACK 3004d5a. Just whitespace change and pure virtual destructor added since last review.

Tree-SHA512: 511de1fb380a18bec1944ea82b513b6192df632ee08bb16344a2df3c40811a88f3872f04df24bc93a41643c96c48f376a04551840fd804a961490d6c702c3d36

…", …) when receiving a transaction we already have

73b96c9 net: Fix uninitialized read in ProcessMessage(...) (practicalswift)

Pull request description:

  Fix an uninitialized read in `ProcessMessage(…, "tx", …)` when receiving a transaction we already have.

  The uninitialized value is read and used on [L2526 in the case of `AlreadyHave(inv) == true`](https://github.com/bitcoin/bitcoin/blob/d8a66626d63135fd245d5afc524b88b9a94d208b/src/net_processing.cpp#L2494-L2526).

  Proof of concept being run against a `bitcoind` built with MemorySanitizer (`-fsanitize=memory`):

  ```
  $ ./p2p-uninit-read-in-conditional-poc.py
  Usage: ./p2p-uninit-read-in-conditional-poc.py <dstaddr> <dstport> <net>
  $ bitcoind -regtest &
  $ ./p2p-uninit-read-in-conditional-poc.py 127.0.0.1 18444 regtest
  SUMMARY: MemorySanitizer: use-of-uninitialized-value
  [1]+  Exit 77                 bitcoind -regtest
  $
  ```

  Proof of concept being run against a `bitcoind` running under Valgrind (`valgrind --exit-on-first-error`):

  ```
  $ valgrind -q --exit-on-first-error=yes --error-exitcode=1 bitcoind -regtest &
  $ ./p2p-uninit-read-in-conditional-poc.py 127.0.0.1 18444 regtest
  ==27351== Conditional jump or move depends on uninitialised value(s)
  [1]+  Exit 1                  valgrind -q --exit-on-first-error=yes --error-exitcode=1 bitcoind -regtest
  $
  ```

  Proof of concept script:

  ```
  #!/usr/bin/env python3

  import sys

  from test_framework.mininode import NetworkThread
  from test_framework.mininode import P2PDataStore
  from test_framework.messages import CTransaction, CTxIn, CTxOut, msg_tx

  def send_duplicate_tx(dstaddr="127.0.0.1", dstport=18444, net="regtest"):
      network_thread = NetworkThread()
      network_thread.start()

      node = P2PDataStore()
      node.peer_connect(dstaddr=dstaddr, dstport=dstport, net=net)()
      node.wait_for_verack()

      tx = CTransaction()
      tx.vin.append(CTxIn())
      tx.vout.append(CTxOut())
      node.send_message(msg_tx(tx))
      node.send_message(msg_tx(tx))
      node.peer_disconnect()
      network_thread.close()

  if __name__ == "__main__":
      if len(sys.argv) != 4:
          print("Usage: {} <dstaddr> <dstport> <net>".format(sys.argv[0]))
          sys.exit(0)
      send_duplicate_tx(sys.argv[1], int(sys.argv[2]), sys.argv[3])
  ```

  Note that the transaction in the proof of concept is the simplest possible, but really any transaction can be used. It does not have to be a valid transaction.

  This bug was introduced in #15921 ("validation: Tidy up ValidationState interface") which was merged in to `master` 28 days ago.

  Luckily this bug was caught before being part of any Bitcoin Core release :)

ACKs for top commit:
  jnewbery:
    utACK 73b96c9
  laanwj:
    ACK 73b96c9, thanks for discovering and reporting this before it ended up in a release.

Tree-SHA512: 7ce6b8f260bcdd9b2ec4ff4b941a891bbef578acf4456df33b7a8d42b248237ec4949e65e2445b24851d1639b10681c701ad500b1c0b776ff050ef8c3812c795

Summary:
This is in preparation for the next commit, which removes the useless
`ret` parameter from ValidationState::Invalid().

error() is simply a convenience wrapper that calls LogPrintf and returns
false. Call LogPrintf explicitly and substitute the error() call for a
false bool literal.

Partial backport of Core [[bitcoin/bitcoin#15921 | PR15921]] : bitcoin/bitcoin@1a37de4

Test Plan: `ninja check check-functional`

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6876

…ckHeaders()

Summary:
No callers use the returned value in first_invalid. Remove it from the
function signature and don't set it in the function.

Partial backport of Core [[bitcoin/bitcoin#15921 | PR15921]] : bitcoin/bitcoin@c428622

Depends on D6873 only to be lint-free.

Test Plan: `ninja check`

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6874

Summary:
ValidationState::Invalid() takes a parameter `ret` which is returned to
the caller. All call sites set this to false. Remove the `ret` parameter
and just return false always.

Partial backport of Core [[bitcoin/bitcoin#15921 | PR15921]] : bitcoin/bitcoin@7204c64

Test Plan: `ninja check check-functional`

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6885

Summary:
Handle this failure in the same way as all other failures: call Invalid()
with the reasons for the failure.

Partial backport of Core [[bitcoin/bitcoin#15921 | PR15921]] : bitcoin/bitcoin@3004d5a

Test Plan: `ninja check check-functional`

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6923

Summary:
3004d5a12d09d94bfc4dee2a8e8f2291996a4aaf [validation] Remove fMissingInputs from AcceptToMemoryPool() (John Newbery)
c428622a5bb1e37b2e6ab2c52791ac05d9271238 [validation] Remove unused first_invalid parameter from ProcessNewBlockHeaders() (John Newbery)
7204c6434b944f6ad51b3c895837729d3aa56eea [validation] Remove useless ret parameter from Invalid() (John Newbery)
1a37de4b3174d19a6d8691ae07e92b32fdfaef11 [validation] Remove error() calls from Invalid() calls (John Newbery)
067981e49246822421a7bcc720491427e1dba8a3 [validation] Tidy Up ValidationResult class (John Newbery)
a27a2957ed9afbe5a96caa5f0f4cbec730d27460 [validation] Add CValidationState subclasses (John Newbery)

Pull request description:

  Carries out some remaining tidy-ups remaining after PR 15141:

  - split ValidationState into TxValidationState and BlockValidationState (commit from ajtowns)
  - various minor code style tidy-ups to the ValidationState class
  - remove the useless `ret` parameter from `ValidationState::Invalid()`
  - remove the now unused `first_invalid` parameter from `ProcessNewBlockHeaders()`
  - remove the `fMissingInputs` parameter from `AcceptToMemoryPool()`, and deal with missing inputs the same way as other errors by using the `TxValidationState` object.

  Tip for reviewers (thanks ryanofsky!): The first commit ("[validation] Add CValidationState subclasses" ) is huge and can be easier to start reviewing if you revert the rote, mechanical changes:

  Substitute the commit hash of commit "[validation] Add CValidationState subclasses" for <CommitHash> in the commands below.

  ```sh
  git checkout <CommitHash>
  git grep -l ValidationState | xargs sed -i 's/BlockValidationState\|TxValidationState/CValidationState/g'
  git grep -l ValidationResult | xargs sed -i 's/BlockValidationResult\|TxValidationResult/ValidationInvalidReason/g'
  git grep -l MaybePunish | xargs sed -i 's/MaybePunishNode\(ForBlock\|ForTx\)/MaybePunishNode/g'
  git diff HEAD^
  ```

  After that it's possible to easily see the mechanical changes with:

  ```sh
  git log -p -n1 -U0 --word-diff-regex=. <CommitHash>
  ```

ACKs for top commit:
  laanwj:
    ACK 3004d5a12d09d94bfc4dee2a8e8f2291996a4aaf
  amitiuttarwar:
    code review ACK 3004d5a12d09d94bfc4dee2a8e8f2291996a4aaf. Also built & ran tests locally.
  fjahr:
    Code review ACK 3004d5a12d09d94bfc4dee2a8e8f2291996a4aaf . Only nit style change and pure virtual destructor added since my last review.
  ryanofsky:
    Code review ACK 3004d5a12d09d94bfc4dee2a8e8f2291996a4aaf. Just whitespace change and pure virtual destructor added since last review.

Tree-SHA512: 511de1fb380a18bec1944ea82b513b6192df632ee08bb16344a2df3c40811a88f3872f04df24bc93a41643c96c48f376a04551840fd804a961490d6c702c3d36

Backport of Core [[bitcoin/bitcoin#15921 | PR15921]] and [[bitcoin/bitcoin#17624 | PR17624]] (small fix to 15921)

Followup to [[bitcoin/bitcoin#15141 | PR15141]]

Some differences reviewers will encounter:
1. RejectCodes (such as REJECT_INVALID) do not appear in the original PR due to an out-of-order backport, but we currently still support them, so it was retained.
2. Some files (notably tests) contain refactors not present in the original PR. This is due to a few out-of-order backports but otherwise harmless.

Depends on D6923, D6929, D6930

Test Plan: `ninja check check-functional-extended`

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6860