Single function smtp::connect::connect_stream
returns a stream of a single `dyn` type
that can be a TLS, STARTTLS or plaintext
connection established over SOCKS5 or directly.
Previously Delta Chat tried all DNS resolution results
in sequence until TCP connection is established successfully,
then tried to establish TLS on top of the TCP connection.
If establishing TLS fails, the whole
connection establishment procedure failed
without trying next DNS resolution results.
In particular, in a scenario
where DNS returns incorrect result
pointing e.g. to a server
that listens on the TCP port
but does not have correpsponding TLS certificate,
Delta Chat now will fall back to the cached result
and connect successfully.
Even though SMTP ALPN is not officially registered (unlike IMAP),
it is an obvious choice that will allow
to multiplex SMTP and other protocols on the same TLS port.
Since commit c0a17df344
(PR https://github.com/deltachat/deltachat-core-rust/pull/3402)
`send_smtp_messages` returns an error
as soon as it encounters the first message it failed to send.
Since this worked like this for about 2 years
without any problems, there is no need to revert the change,
but outdated comment should be removed.
If a time value doesn't need to be sent to another host, saved to the db or otherwise used across
program restarts, a monotonically nondecreasing clock (`Instant`) should be used. But as `Instant`
may use `libc::clock_gettime(CLOCK_MONOTONIC)`, e.g. on Android, and does not advance while being in
deep sleep mode, get rid of `Instant` in favor of using `SystemTime`, but add `tools::Time` as an
alias for it with the appropriate comment so that it's clear why `Instant` isn't used in those
places and to protect from unwanted usages of `Instant` in the future. Also this can help to switch
to another clock impl if we find any.
a27e84ad89 "fix: Delete received outgoing messages from SMTP queue"
can break sending messages sent as several SMTP messages because they have a lot of recipients:
`pub(crate) const DEFAULT_MAX_SMTP_RCPT_TO: usize = 50;`
We should not cancel sending if it is such a message and we received BCC-self because it does not
mean the other part was sent successfully. For this, split such messages into separate jobs in the
`smtp` table so that only a job containing BCC-self is canceled from `receive_imf_inner()`. Although
this doesn't solve the initial problem with timed-out SMTP requests for such messages completely,
this enables fine-grained SMTP retries so we don't need to resend all SMTP messages if only some of
them failed to be sent.
If there's a temporary SMTP error, pretend there are no more MDNs to send in send_mdn(). It's
unlikely that other MDNs could be sent successfully in case of connectivity problems. This approach
is simpler and perhaps even better than adding a progressive backoff between MDN sending retries --
MDNs just will be resent after a reconnection, which makes some sense.
I.e. from delete_msgs(). Otherwise messages must not be deleted from there, e.g. if a message is
ephemeral, but a network outage lasts longer than the ephemeral message timer, the message still
must be sent upon a successful reconnection.
I.e. from delete_msgs(). Otherwise messages must not be deleted from there, e.g. if a message is
ephemeral, but a network outage lasts longer than the ephemeral message timer, the message still
must be sent upon a successful reconnection.
Moved custom ToSql trait including Send + Sync from lib.rs to sql.rs.
Replaced most params! and paramsv! macro usage with tuples.
Replaced paramsv! and params_iterv! with params_slice!,
because there is no need to construct a vector.
async-smtp does not implement read buffering anymore
and expects library user to implement it.
To implement read buffer, we wrap streams into BufStream
instead of BufWriter.
* more flexible render_webxdc_status_update_object()
* delay webxdc updates when ratelimit is reached
* inject updates messages to the SMTP loop as needed
this avoids starting several tasks
and allows sending updates out after a restart of the app.
* use mutex to prevent race conditions in status updates
* check ratelimiter only before the sending loop; it won't change until messages are actually sent out
* fix typo
* prefer standard type declaration over turbofish syntax
* use UNIQUE and ON CONFLICT for query smtp_status_updates
* combine DELETE+SELECT to one atomic statement
* as all operations on smtp_status_updates are now atomic, a mutex is no longer needed
* test DELETE+RETURNING statement
* simplify calls to can_send()
* comment about ratelimit boolean in send_smtp_messages()
This makes sure that under normal circumstances the LoginParam struct
is always fully validated, ensure future use does not have to be
careful with this.
The brittle handling of `server_flags` is also abstraced away from
users of it and is now handled entirely internally, as the flags is
really only a boolean a lot of the flag parsing complexity is removed.
The OAuth2 flag is moved into the ServerLoginParam struct as it really
belongs in there.
New ratelimiter module counts number of sent messages and calculates
the time until more messages can be sent.
Rate limiter is currently applied only to MDNs. Other messages are
sent without rate limiting even if quota is exceeded, but MDNs are not
sent until ratelimiter allows sending again.
