We want `Get()` to always return the same value, otherwise it will look
like the `FuzzedSock` implementation itself is broken. So assign
`m_socket` a random number in the `FuzzedSock` constructor.
There is nothing to fuzz about the `Get()` and `Release()` methods, so
use the ones from the base class `Sock`.
`Reset()` is just setting our socket to `INVALID_SOCKET`. We don't want
to use the base `Reset()` because it will close `m_socket` and given
that our `m_socket` is just a random number it may end up closing a real
opened file descriptor if it coincides with our random `m_socket`.
Put a limit on the amount of data `Sock::RecvUntilTerminator()` can read
if no terminator is received.
In the case of I2P this avoids a runaway (or malicious) I2P proxy
sending us tons of data without a terminator before a timeout is
triggered.
Introduce two high level, convenience methods in the `Sock` class:
* `SendComplete()`: keep trying to send the specified data until either
successfully sent all of it, timeout or interrupted.
* `RecvUntilTerminator()`: read until a terminator is encountered (never
after it), timeout or interrupted.
These will be convenient in the I2P SAM implementation.
`SendComplete()` can also be used in the SOCKS5 implementation instead
of calling `send()` directly.
Previously `Sock::Wait()` would not have signaled to the caller whether
a timeout or one of the requested events occurred since that was not
needed by any of the callers.
Such functionality will be needed in the I2P implementation, thus extend
the `Sock::Wait()` method.
Introduce a class to manage the lifetime of a socket - when the object
that contains the socket goes out of scope, the underlying socket will
be closed.
In addition, the new `Sock` class has a `Send()`, `Recv()` and `Wait()`
methods that can be overridden by unit tests to mock the socket
operations.
The `Wait()` method also hides the
`#ifdef USE_POLL poll() #else select() #endif` technique from higher
level code.
Move `CloseSocket()` (and `NetworkErrorString()` which it uses) from
`netbase.{h,cpp}` to newly added `src/util/sock.{h,cpp}`.
This is necessary in order to use `CloseSocket()` from a newly
introduced Sock class (which will live in `src/util/sock.{h,cpp}`).
`sock.{h,cpp}` cannot depend on netbase because netbase will depend
on it.
