SSL_GET_CONN_CLOSE_INFO(3SSL) OpenSSL SSL_GET_CONN_CLOSE_INFO(3SSL)
NAME
SSL_get_conn_close_info, SSL_CONN_CLOSE_FLAG_LOCAL,
SSL_CONN_CLOSE_FLAG_TRANSPORT, OSSL_QUIC_ERR_NO_ERROR,
OSSL_QUIC_ERR_INTERNAL_ERROR, OSSL_QUIC_ERR_CONNECTION_REFUSED,
OSSL_QUIC_ERR_FLOW_CONTROL_ERROR, OSSL_QUIC_ERR_STREAM_LIMIT_ERROR,
OSSL_QUIC_ERR_STREAM_STATE_ERROR, OSSL_QUIC_ERR_FINAL_SIZE_ERROR,
OSSL_QUIC_ERR_FRAME_ENCODING_ERROR,
OSSL_QUIC_ERR_TRANSPORT_PARAMETER_ERROR,
OSSL_QUIC_ERR_CONNECTION_ID_LIMIT_ERROR,
OSSL_QUIC_ERR_PROTOCOL_VIOLATION, OSSL_QUIC_ERR_INVALID_TOKEN,
OSSL_QUIC_ERR_APPLICATION_ERROR, OSSL_QUIC_ERR_CRYPTO_BUFFER_EXCEEDED,
OSSL_QUIC_ERR_KEY_UPDATE_ERROR, OSSL_QUIC_ERR_AEAD_LIMIT_REACHED,
OSSL_QUIC_ERR_NO_VIABLE_PATH, OSSL_QUIC_ERR_CRYPTO_ERR_BEGIN,
OSSL_QUIC_ERR_CRYPTO_ERR_END, OSSL_QUIC_ERR_CRYPTO_ERR,
OSSL_QUIC_LOCAL_ERR_IDLE_TIMEOUT - get information about why a QUIC
connection was closed
SYNOPSIS
#include <openssl/ssl.h>
#define SSL_CONN_CLOSE_FLAG_LOCAL
#define SSL_CONN_CLOSE_FLAG_TRANSPORT
typedef struct ssl_conn_close_info_st {
uint64_t error_code, frame_type;
char *reason;
size_t reason_len;
uint32_t flags;
} SSL_CONN_CLOSE_INFO;
int SSL_get_conn_close_info(SSL *ssl, SSL_CONN_CLOSE_INFO *info,
size_t info_len);
#define OSSL_QUIC_ERR_NO_ERROR 0x00
#define OSSL_QUIC_ERR_INTERNAL_ERROR 0x01
#define OSSL_QUIC_ERR_CONNECTION_REFUSED 0x02
#define OSSL_QUIC_ERR_FLOW_CONTROL_ERROR 0x03
#define OSSL_QUIC_ERR_STREAM_LIMIT_ERROR 0x04
#define OSSL_QUIC_ERR_STREAM_STATE_ERROR 0x05
#define OSSL_QUIC_ERR_FINAL_SIZE_ERROR 0x06
#define OSSL_QUIC_ERR_FRAME_ENCODING_ERROR 0x07
#define OSSL_QUIC_ERR_TRANSPORT_PARAMETER_ERROR 0x08
#define OSSL_QUIC_ERR_CONNECTION_ID_LIMIT_ERROR 0x09
#define OSSL_QUIC_ERR_PROTOCOL_VIOLATION 0x0A
#define OSSL_QUIC_ERR_INVALID_TOKEN 0x0B
#define OSSL_QUIC_ERR_APPLICATION_ERROR 0x0C
#define OSSL_QUIC_ERR_CRYPTO_BUFFER_EXCEEDED 0x0D
#define OSSL_QUIC_ERR_KEY_UPDATE_ERROR 0x0E
#define OSSL_QUIC_ERR_AEAD_LIMIT_REACHED 0x0F
#define OSSL_QUIC_ERR_NO_VIABLE_PATH 0x10
/* Inclusive range for handshake-specific errors. */
#define OSSL_QUIC_ERR_CRYPTO_ERR_BEGIN 0x0100
#define OSSL_QUIC_ERR_CRYPTO_ERR_END 0x01FF
#define OSSL_QUIC_ERR_CRYPTO_ERR(X)
#define OSSL_QUIC_LOCAL_ERR_IDLE_TIMEOUT
DESCRIPTION
The SSL_get_conn_close_info() function provides information about why
and how a QUIC connection was closed.
Connection closure information is written to *info, which must be non-
NULL. info_len must be set to sizeof(*info).
The following fields are set:
error_code
This is a 62-bit QUIC error code. It is either a 62-bit application
error code (if SSL_CONN_CLOSE_FLAG_TRANSPORT not set in flags) or a
62-bit standard QUIC transport error code (if
SSL_CONN_CLOSE_FLAG_TRANSPORT is set in flags).
frame_type
If SSL_CONN_CLOSE_FLAG_TRANSPORT is set, this may be set to a QUIC
frame type number which caused the connection to be closed. It may
also be set to 0 if no frame type was specified as causing the
connection to be closed. If SSL_CONN_CLOSE_FLAG_TRANSPORT is not
set, this is set to 0.
reason
If non-NULL, this is intended to be a UTF-8 textual string briefly
describing the reason for connection closure. The length of the
reason string in bytes is given in reason_len. While, if non-NULL,
OpenSSL guarantees that this string will be zero terminated,
consider that this buffer may originate from the (untrusted) peer
and thus may also contain zero bytes elsewhere. Therefore, use of
reason_len is recommended.
While it is intended as per the QUIC protocol that this be a UTF-8
string, there is no guarantee that this is the case for strings
received from the peer.
SSL_CONN_CLOSE_FLAG_LOCAL
If flags has SSL_CONN_CLOSE_FLAG_LOCAL set, connection closure was
locally triggered. This could be due to an application request (e.g.
if SSL_CONN_CLOSE_FLAG_TRANSPORT is unset), or (if
SSL_CONN_CLOSE_FLAG_TRANSPORT is set) due to logic internal to the
QUIC implementation (for example, if the peer engages in a protocol
violation, or an idle timeout occurs).
If unset, connection closure was remotely triggered.
SSL_CONN_CLOSE_FLAG_TRANSPORT
If flags has SSL_CONN_CLOSE_FLAG_TRANSPORT set, connection closure
was triggered for QUIC protocol reasons. Otherwise, connection
closure was triggered by the local or remote application.
The OSSL_QUIC_ERR macro definitions provide the QUIC transport error
codes as defined by RFC 9000. The OSSL_QUIC_ERR_CRYPTO_ERR() macro can
be used to convert a TLS alert code into a QUIC transport error code by
mapping it into the range reserved for such codes by RFC 9000. This
range begins at OSSL_QUIC_ERR_CRYPTO_ERR_BEGIN and ends at
OSSL_QUIC_ERR_CRYPTO_ERR_END inclusive.
NON-STANDARD TRANSPORT ERROR CODES
Some conditions which can cause QUIC connection termination are not
signalled on the wire and therefore do not have standard error codes.
OpenSSL indicates these errors via SSL_get_conn_close_info() by setting
SSL_CONN_CLOSE_FLAG_TRANSPORT and using one of the following error
values. These codes are specific to OpenSSL, and cannot be sent over the
wire, as they are above 2**62.
OSSL_QUIC_LOCAL_ERR_IDLE_TIMEOUT
The connection was terminated immediately due to the idle timeout
expiring.
RETURN VALUES
SSL_get_conn_close_info() returns 1 on success and 0 on failure. This
function fails if called on a QUIC connection SSL object which has not
yet been terminated. It also fails if called on a QUIC stream SSL object
or a non-QUIC SSL object.
SEE ALSO
SSL_shutdown_ex(3)
HISTORY
This function was added in OpenSSL 3.2.
COPYRIGHT
Copyright 2002-2024 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.5.7 2026-06-09 SSL_GET_CONN_CLOSE_INFO(3SSL)
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