Revert "resolved: don't wait for TLS close_notify replies unnecessarily"

This change introduced a regression that stops DNSOverTLS from working
after some time. Revert it for now, as there's no fixup available at
the moment.

Fixes https://github.com/systemd/systemd/issues/38509

This reverts commit 4b6dbd4ea5.
This commit is contained in:
Luca Boccassi
2025-08-20 14:04:27 +02:00
committed by Zbigniew Jędrzejewski-Szmek
parent 39a8eb9e32
commit e9caf17f63
+58 -45
View File
@@ -162,39 +162,42 @@ int dnstls_stream_on_io(DnsStream *stream, uint32_t revents) {
}
if (stream->dnstls_data.shutdown) {
/* NB: when a shutdown is initiated by us we'll wait until the close_notify TLS message is
* sent out, but we'll not wait for the reply to it, to minimize dependencies on slow
* servers */
ERR_clear_error();
r = SSL_shutdown(stream->dnstls_data.ssl);
if (r < 0) {
error = SSL_get_error(stream->dnstls_data.ssl, r);
if (error == SSL_ERROR_WANT_READ)
stream->dnstls_events = EPOLLIN;
else if (error == SSL_ERROR_WANT_WRITE)
stream->dnstls_events = EPOLLOUT;
else if (error == SSL_ERROR_SYSCALL) {
if (errno != 0)
log_debug_errno(errno, "Failed to invoke SSL_shutdown(), ignoring: %m");
else
log_debug("Failed to invoke SSL_shutdown(), ignoring (unknown system error).");
} else
log_debug("Failed to invoke SSL_shutdown(), ignoring: %s", DNSTLS_ERROR_STRING(error));
} else
if (r == 0) {
stream->dnstls_events = 0;
r = dnstls_flush_write_buffer(stream);
if (r < 0)
return r;
return -EAGAIN;
} else if (r < 0) {
error = SSL_get_error(stream->dnstls_data.ssl, r);
if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) {
stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT;
r = dnstls_flush_write_buffer(stream);
if (r < 0)
return r;
return -EAGAIN;
} else if (error == SSL_ERROR_SYSCALL) {
if (errno > 0)
log_debug_errno(errno, "Failed to invoke SSL_shutdown, ignoring: %m");
} else
log_debug("Failed to invoke SSL_shutdown, ignoring: %s", DNSTLS_ERROR_STRING(error));
}
stream->dnstls_events = 0;
stream->dnstls_data.shutdown = false;
r = dnstls_flush_write_buffer(stream);
if (r < 0)
return r;
/* All data written? Then we are done, release the stream */
stream->dnstls_data.shutdown = false;
dns_stream_unref(stream);
return DNSTLS_STREAM_CLOSED;
} else if (stream->dnstls_data.handshake <= 0) {
ERR_clear_error();
stream->dnstls_data.handshake = SSL_do_handshake(stream->dnstls_data.ssl);
@@ -241,35 +244,45 @@ int dnstls_stream_shutdown(DnsStream *stream, int error) {
}
if (error == ETIMEDOUT) {
/* Initiate a shutdown from our side, and remember so. Pin the stream until that's complete. */
if (!stream->dnstls_data.shutdown) {
stream->dnstls_data.shutdown = true;
dns_stream_ref(stream);
}
ERR_clear_error();
r = SSL_shutdown(stream->dnstls_data.ssl);
if (r < 0) {
ssl_error = SSL_get_error(stream->dnstls_data.ssl, r);
if (ssl_error == SSL_ERROR_WANT_READ)
stream->dnstls_events = EPOLLIN;
else if (ssl_error == SSL_ERROR_WANT_WRITE)
stream->dnstls_events = EPOLLOUT;
else if (ssl_error == SSL_ERROR_SYSCALL) {
if (errno != 0)
log_debug_errno(errno, "Failed to invoke SSL_shutdown(), ignoring: %m");
else
log_debug("Failed to invoke SSL_shutdown(), ignoring (unknown system error).");
} else
log_debug("Failed to invoke SSL_shutdown(), ignoring: %s", DNSTLS_ERROR_STRING(error));
} else
if (r == 0) {
if (!stream->dnstls_data.shutdown) {
stream->dnstls_data.shutdown = true;
dns_stream_ref(stream);
}
stream->dnstls_events = 0;
r = dnstls_flush_write_buffer(stream);
if (r < 0)
return r;
return -EAGAIN;
} else if (r < 0) {
ssl_error = SSL_get_error(stream->dnstls_data.ssl, r);
if (IN_SET(ssl_error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) {
stream->dnstls_events = ssl_error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT;
r = dnstls_flush_write_buffer(stream);
if (r < 0 && r != -EAGAIN)
return r;
if (!stream->dnstls_data.shutdown) {
stream->dnstls_data.shutdown = true;
dns_stream_ref(stream);
}
return -EAGAIN;
} else if (ssl_error == SSL_ERROR_SYSCALL) {
if (errno > 0)
log_debug_errno(errno, "Failed to invoke SSL_shutdown, ignoring: %m");
} else
log_debug("Failed to invoke SSL_shutdown, ignoring: %s", DNSTLS_ERROR_STRING(ssl_error));
}
stream->dnstls_events = 0;
r = dnstls_flush_write_buffer(stream);
if (r < 0)
return r;
/* dnstls_stream_on_io() will complete the shutdown for us */
}
return 0;