ooni-probe-cli/internal/engine/netx
Simone Basso b5da8be183
fix(netxlite): robust {ReadAll,Copy}Context with wrapped io.EOF (#661)
* chore(netxlite): add currently failing test case

This diff introduces a test cases that will fail because of the reason
explained in https://github.com/ooni/probe/issues/1965.

* chore(netxlite/iox_test.go): add failing unit tests

These tests directly show how the Go implementation of ReadAll
and Copy has the issue of checking for io.EOF equality.

* fix(netxlite): make {ReadAll,Copy}Context robust to wrapped io.EOF

The fix is simple: we just need to check for `errors.Is(err, io.EOF)`
after either io.ReadAll or io.Copy has returned. When this condition is
true, we need to convert the error back to `nil` as it ought to be.

While there, observe that the unit tests I committed in the previous
commit are wrongly asserting that the error must be wrapped. This
assertion is not correct, because in both cases we have just ensured
that the returned error is `nil` (i.e., success).

See https://github.com/ooni/probe/issues/1965.

* cleanup: remove previous workaround for wrapped io.EOF

These workarounds were partial, meaning that they would cover some
cases in which the issue occurred but not all of them.

Handling the problem in `netxlite.{ReadAll,Copy}Context` is the
right thing to do _as long as_ we always use these functions instead
of `io.{ReadAll,Copy}`.

This is why it's now important to ensure we clearly mention that
inside of the `CONTRIBUTING.md` guide and to also ensure that we're
not using these functions in the code base.

* fix(urlgetter): repair tests who assumed to see EOF error

Now that we have established that we should normalize EOF when
reading bodies like the stdlib does and now that it's clear why
our behavior diverged from the stdlib, we also need to repair
all the tests that assumed this incorrect behavior.

* fix(all): don't use io{,util}.{Copy,ReadAll}

* feat: add checks to ensure we don't use io.{Copy,ReadAll}

* doc(netxlite): document we know how to deal w/ wrapped io.EOF

* fix(nocopyreadall.bash): add exception for i/n/iox.go
2022-01-12 14:26:10 +01:00
..
archival refactor: move i/netx/archival structs to i/model (#659) 2022-01-10 11:25:52 +01:00
dialer cleanup: remove unnecessary legacy interfaces (#656) 2022-01-07 18:33:37 +01:00
httptransport fix(netxlite): robust {ReadAll,Copy}Context with wrapped io.EOF (#661) 2022-01-12 14:26:10 +01:00
quicdialer cleanup: remove unnecessary legacy interfaces (#656) 2022-01-07 18:33:37 +01:00
resolver cleanup(netx): remove more legacy names and functions (#658) 2022-01-07 20:02:19 +01:00
tlsdialer cleanup: remove unnecessary legacy interfaces (#656) 2022-01-07 18:33:37 +01:00
trace chore: merge probe-engine into probe-cli (#201) 2021-02-02 12:05:47 +01:00
fake_test.go cleanup: remove unnecessary legacy interfaces (#656) 2022-01-07 18:33:37 +01:00
integration_test.go refactor: merge dnsx and errorsx into netxlite (#517) 2021-09-28 12:42:01 +02:00
netx_internal_test.go chore: merge probe-engine into probe-cli (#201) 2021-02-02 12:05:47 +01:00
netx_test.go cleanup(netx): remove the DNSClient type (#660) 2022-01-10 11:53:06 +01:00
netx.go cleanup(netx): remove the DNSClient type (#660) 2022-01-10 11:53:06 +01:00
README.md chore: merge probe-engine into probe-cli (#201) 2021-02-02 12:05:47 +01:00

Package github.com/ooni/probe-engine/netx

OONI extensions to the net and net/http packages. This code is used by ooni/probe-engine as a low level library to collect network, DNS, and HTTP events occurring during OONI measurements.

This library contains replacements for commonly used standard library interfaces that facilitate seamless network measurements. By using such replacements, as opposed to standard library interfaces, we can:

  • save the timing of HTTP events (e.g. received response headers)
  • save the timing and result of every Connect, Read, Write, Close operation
  • save the timing and result of the TLS handshake (including certificates)

By default, this library uses the system resolver. In addition, it is possible to configure alternative DNS transports and remote servers. We support DNS over UDP, DNS over TCP, DNS over TLS (DoT), and DNS over HTTPS (DoH). When using an alternative transport, we are also able to intercept and save DNS messages, as well as any other interaction with the remote server (e.g., the result of the TLS handshake for DoT and DoH).

This package is a fork of github.com/ooni/netx.