[PATCH net-next v3 05/15] quic: provide quic.h header files for kernel and userspace

Xin Long
2025-09-18T22:39:14Z

This commit adds quic.h to include/uapi/linux, providing the necessary
definitions for the QUIC socket API. Exporting this header allows both
user space applications and kernel subsystems to access QUIC-related
control messages, socket options, and event/notification interfaces.

Since kernel_get/setsockopt() is no longer available to kernel consumers,
a corresponding internal header, include/linux/quic.h, is added. This
provides kernel subsystems with the necessary declarations to handle
QUIC socket options directly.

Detailed descriptions of these structures are available in [1], and will
be also provided when adding corresponding socket interfaces in the
later patches.

[1] https://datatracker.ietf.org/doc/html/draft-lxin-quic-socket-apis

Signed-off-by: Tyler Fanelli <tfanelli@redhat.com>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
v2:
- Fix a kernel API description warning, found by Jakub.
- Replace uintN_t with __uN, capitalize _UAPI_LINUX_QUIC_H, and
assign explicit values for QUIC_TRANSPORT_ERROR_ enum in UAPI
quic.h, suggested by David Howells.
---
include/linux/quic.h | 19 +++
include/uapi/linux/quic.h | 236 ++++++++++++++++++++++++++++++++++++++
net/quic/socket.c | 38 ++++++
net/quic/socket.h | 7 ++
4 files changed, 300 insertions(+)
create mode 100644 include/linux/quic.h
create mode 100644 include/uapi/linux/quic.h

diff --git a/include/linux/quic.h b/include/linux/quic.h
new file mode 100644
index 000000000000..d35ff40bb005
--- /dev/null
+++ b/include/linux/quic.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* QUIC kernel implementation
+ * (C) Copyright Red Hat Corp. 2023
+ *
+ * This file is part of the QUIC kernel implementation
+ *
+ * Written or modified by:
+ * Xin Long <lucien.xin@gmail.com>
+ */
+
+#ifndef _LINUX_QUIC_H
+#define _LINUX_QUIC_H
+
+#include <uapi/linux/quic.h>
+
+int quic_kernel_setsockopt(struct sock *sk, int optname, void *optval, unsigned int optlen);
+int quic_kernel_getsockopt(struct sock *sk, int optname, void *optval, unsigned int *optlen);
+
+#endif
diff --git a/include/uapi/linux/quic.h b/include/uapi/linux/quic.h
new file mode 100644
index 000000000000..f7c85399ac4a
--- /dev/null
+++ b/include/uapi/linux/quic.h
@@ -0,0 +1,236 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/* QUIC kernel implementation
+ * (C) Copyright Red Hat Corp. 2023
+ *
+ * This file is part of the QUIC kernel implementation
+ *
+ * Written or modified by:
+ * Xin Long <lucien.xin@gmail.com>
+ */
+
+#ifndef _UAPI_LINUX_QUIC_H
+#define _UAPI_LINUX_QUIC_H
+
+#include <linux/types.h>
+#ifdef __KERNEL__
+#include <linux/socket.h>
+#else
+#include <sys/socket.h>
+#endif
+
+/* NOTE: Structure descriptions are specified in:
+ * https://datatracker.ietf.org/doc/html/draft-lxin-quic-socket-apis
+ */
+
+/* Send or Receive Options APIs */
+enum quic_cmsg_type {
+ QUIC_STREAM_INFO,
+ QUIC_HANDSHAKE_INFO,
+};
+
+#define QUIC_STREAM_TYPE_SERVER_MASK 0x01
+#define QUIC_STREAM_TYPE_UNI_MASK 0x02
+#define QUIC_STREAM_TYPE_MASK 0x03
+
+enum quic_msg_flags {
+ /* flags for stream_flags */
+ MSG_STREAM_NEW = MSG_SYN,
+ MSG_STREAM_FIN = MSG_FIN,
+ MSG_STREAM_UNI = MSG_CONFIRM,
+ MSG_STREAM_DONTWAIT = MSG_WAITFORONE,
+ MSG_STREAM_SNDBLOCK = MSG_ERRQUEUE,
+
+ /* extented flags for msg_flags */
+ MSG_DATAGRAM = MSG_RST,
+ MSG_NOTIFICATION = MSG_MORE,
+};
+
+enum quic_crypto_level {
+ QUIC_CRYPTO_APP,
+ QUIC_CRYPTO_INITIAL,
+ QUIC_CRYPTO_HANDSHAKE,
+ QUIC_CRYPTO_EARLY,
+ QUIC_CRYPTO_MAX,
+};
+
+struct quic_handshake_info {
+ __u8 crypto_level;
+};
+
+struct quic_stream_info {
+ __s64 stream_id;
+ __u32 stream_flags;
+};
+
+/* Socket Options APIs */
+#define QUIC_SOCKOPT_EVENT 0
+#define QUIC_SOCKOPT_STREAM_OPEN 1
+#define QUIC_SOCKOPT_STREAM_RESET 2
+#define QUIC_SOCKOPT_STREAM_STOP_SENDING 3
+#define QUIC_SOCKOPT_CONNECTION_ID 4
+#define QUIC_SOCKOPT_CONNECTION_CLOSE 5
+#define QUIC_SOCKOPT_CONNECTION_MIGRATION 6
+#define QUIC_SOCKOPT_KEY_UPDATE 7
+#define QUIC_SOCKOPT_TRANSPORT_PARAM 8
+#define QUIC_SOCKOPT_CONFIG 9
+#define QUIC_SOCKOPT_TOKEN 10
+#define QUIC_SOCKOPT_ALPN 11
+#define QUIC_SOCKOPT_SESSION_TICKET 12
+#define QUIC_SOCKOPT_CRYPTO_SECRET 13
+#define QUIC_SOCKOPT_TRANSPORT_PARAM_EXT 14
+
+#define QUIC_VERSION_V1 0x1
+#define QUIC_VERSION_V2 0x6b3343cf
+
+struct quic_transport_param {
+ __u8 remote;
+ __u8 disable_active_migration;
+ __u8 grease_quic_bit;
+ __u8 stateless_reset;
+ __u8 disable_1rtt_encryption;
+ __u8 disable_compatible_version;
+ __u8 active_connection_id_limit;
+ __u8 ack_delay_exponent;
+ __u16 max_datagram_frame_size;
+ __u16 max_udp_payload_size;
+ __u32 max_idle_timeout;
+ __u32 max_ack_delay;
+ __u16 max_streams_bidi;
+ __u16 max_streams_uni;
+ __u64 max_data;
+ __u64 max_stream_data_bidi_local;
+ __u64 max_stream_data_bidi_remote;
+ __u64 max_stream_data_uni;
+ __u64 reserved;
+};
+
+struct quic_config {
+ __u32 version;
+ __u32 plpmtud_probe_interval;
+ __u32 initial_smoothed_rtt;
+ __u32 payload_cipher_type;
+ __u8 congestion_control_algo;
+ __u8 validate_peer_address;
+ __u8 stream_data_nodelay;
+ __u8 receive_session_ticket;
+ __u8 certificate_request;
+ __u8 reserved[3];
+};
+
+struct quic_crypto_secret {
+ __u8 send; /* send or recv */
+ __u8 level; /* crypto level */
+ __u32 type; /* TLS_CIPHER_* */
+#define QUIC_CRYPTO_SECRET_BUFFER_SIZE 48
+ __u8 secret[QUIC_CRYPTO_SECRET_BUFFER_SIZE];
+};
+
+enum quic_cong_algo {
+ QUIC_CONG_ALG_RENO,
+ QUIC_CONG_ALG_CUBIC,
+ QUIC_CONG_ALG_MAX,
+};
+
+struct quic_errinfo {
+ __s64 stream_id;
+ __u32 errcode;
+};
+
+struct quic_connection_id_info {
+ __u8 dest;
+ __u32 active;
+ __u32 prior_to;
+};
+
+struct quic_event_option {
+ __u8 type;
+ __u8 on;
+};
+
+/* Event APIs */
+enum quic_event_type {
+ QUIC_EVENT_NONE,
+ QUIC_EVENT_STREAM_UPDATE,
+ QUIC_EVENT_STREAM_MAX_DATA,
+ QUIC_EVENT_STREAM_MAX_STREAM,
+ QUIC_EVENT_CONNECTION_ID,
+ QUIC_EVENT_CONNECTION_CLOSE,
+ QUIC_EVENT_CONNECTION_MIGRATION,
+ QUIC_EVENT_KEY_UPDATE,
+ QUIC_EVENT_NEW_TOKEN,
+ QUIC_EVENT_NEW_SESSION_TICKET,
+ QUIC_EVENT_MAX,
+};
+
+enum {
+ QUIC_STREAM_SEND_STATE_READY,
+ QUIC_STREAM_SEND_STATE_SEND,
+ QUIC_STREAM_SEND_STATE_SENT,
+ QUIC_STREAM_SEND_STATE_RECVD,
+ QUIC_STREAM_SEND_STATE_RESET_SENT,
+ QUIC_STREAM_SEND_STATE_RESET_RECVD,
+
+ QUIC_STREAM_RECV_STATE_RECV,
+ QUIC_STREAM_RECV_STATE_SIZE_KNOWN,
+ QUIC_STREAM_RECV_STATE_RECVD,
+ QUIC_STREAM_RECV_STATE_READ,
+ QUIC_STREAM_RECV_STATE_RESET_RECVD,
+ QUIC_STREAM_RECV_STATE_RESET_READ,
+};
+
+struct quic_stream_update {
+ __s64 id;
+ __u8 state;
+ __u32 errcode;
+ __u64 finalsz;
+};
+
+struct quic_stream_max_data {
+ __s64 id;
+ __u64 max_data;
+};
+
+struct quic_connection_close {
+ __u32 errcode;
+ __u8 frame;
+ __u8 phrase[];
+};
+
+union quic_event {
+ struct quic_stream_update update;
+ struct quic_stream_max_data max_data;
+ struct quic_connection_close close;
+ struct quic_connection_id_info info;
+ __u64 max_stream;
+ __u8 local_migration;
+ __u8 key_update_phase;
+};
+
+enum {
+ QUIC_TRANSPORT_ERROR_NONE = 0x00,
+ QUIC_TRANSPORT_ERROR_INTERNAL = 0x01,
+ QUIC_TRANSPORT_ERROR_CONNECTION_REFUSED = 0x02,
+ QUIC_TRANSPORT_ERROR_FLOW_CONTROL = 0x03,
+ QUIC_TRANSPORT_ERROR_STREAM_LIMIT = 0x04,
+ QUIC_TRANSPORT_ERROR_STREAM_STATE = 0x05,
+ QUIC_TRANSPORT_ERROR_FINAL_SIZE = 0x06,
+ QUIC_TRANSPORT_ERROR_FRAME_ENCODING = 0x07,
+ QUIC_TRANSPORT_ERROR_TRANSPORT_PARAM = 0x08,
+ QUIC_TRANSPORT_ERROR_CONNECTION_ID_LIMIT = 0x09,
+ QUIC_TRANSPORT_ERROR_PROTOCOL_VIOLATION = 0x0a,
+ QUIC_TRANSPORT_ERROR_INVALID_TOKEN = 0x0b,
+ QUIC_TRANSPORT_ERROR_APPLICATION = 0x0c,
+ QUIC_TRANSPORT_ERROR_CRYPTO_BUF_EXCEEDED = 0x0d,
+ QUIC_TRANSPORT_ERROR_KEY_UPDATE = 0x0e,
+ QUIC_TRANSPORT_ERROR_AEAD_LIMIT_REACHED = 0x0f,
+ QUIC_TRANSPORT_ERROR_NO_VIABLE_PATH = 0x10,
+
+ /* The cryptographic handshake failed. A range of 256 values is reserved
+ * for carrying error codes specific to the cryptographic handshake that
+ * is used. Codes for errors occurring when TLS is used for the
+ * cryptographic handshake are described in Section 4.8 of [QUIC-TLS].
+ */
+ QUIC_TRANSPORT_ERROR_CRYPTO = 0x0100,
+};
+
+#endif /* _UAPI_LINUX_QUIC_H */
diff --git a/net/quic/socket.c b/net/quic/socket.c
index 0b8fec63f769..08d21389c52e 100644
--- a/net/quic/socket.c
+++ b/net/quic/socket.c
@@ -121,6 +121,25 @@ static int quic_setsockopt(struct sock *sk, int level, int optname,
return quic_do_setsockopt(sk, optname, optval, optlen);
}

+/**
+ * quic_kernel_setsockopt - set a QUIC socket option from within the kernel
+ * @sk: socket to configure
+ * @optname: option name (QUIC-level)
+ * @optval: pointer to the option value
+ * @optlen: size of the option value
+ *
+ * Sets a QUIC socket option on a kernel socket without involving user space.
+ *
+ * Return:
+ * - On success, 0 is returned.
+ * - On error, a negative error value is returned.
+ */
+int quic_kernel_setsockopt(struct sock *sk, int optname, void *optval, unsigned int optlen)
+{
+ return quic_do_setsockopt(sk, optname, KERNEL_SOCKPTR(optval), optlen);
+}
+EXPORT_SYMBOL_GPL(quic_kernel_setsockopt);
+
static int quic_do_getsockopt(struct sock *sk, int optname, sockptr_t optval, sockptr_t optlen)
{
return -EOPNOTSUPP;
@@ -135,6 +154,25 @@ static int quic_getsockopt(struct sock *sk, int level, int optname,
return quic_do_getsockopt(sk, optname, USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
}

+/**
+ * quic_kernel_getsockopt - get a QUIC socket option from within the kernel
+ * @sk: socket to query
+ * @optname: option name (QUIC-level)
+ * @optval: pointer to the buffer to receive the option value
+ * @optlen: pointer to the size of the buffer; updated to actual length on return
+ *
+ * Gets a QUIC socket option from a kernel socket, bypassing user space.
+ *
+ * Return:
+ * - On success, 0 is returned.
+ * - On error, a negative error value is returned.
+ */
+int quic_kernel_getsockopt(struct sock *sk, int optname, void *optval, unsigned int *optlen)
+{
+ return quic_do_getsockopt(sk, optname, KERNEL_SOCKPTR(optval), KERNEL_SOCKPTR(optlen));
+}
+EXPORT_SYMBOL_GPL(quic_kernel_getsockopt);
+
static void quic_release_cb(struct sock *sk)
{
}
diff --git a/net/quic/socket.h b/net/quic/socket.h
index 3f808489f571..aeaefc677973 100644
--- a/net/quic/socket.h
+++ b/net/quic/socket.h
@@ -9,6 +9,7 @@
*/

#include <net/udp_tunnel.h>
+#include <linux/quic.h>

#include "common.h"
#include "family.h"
@@ -29,6 +30,7 @@ struct quic_sock {
struct inet_sock inet;
struct list_head reqs;

+ struct quic_config config;
struct quic_data ticket;
struct quic_data token;
struct quic_data alpn;
@@ -49,6 +51,11 @@ static inline struct list_head *quic_reqs(const struct sock *sk)
return &quic_sk(sk)->reqs;
}

+static inline struct quic_config *quic_config(const struct sock *sk)
+{
+ return &quic_sk(sk)->config;
+}
+
static inline struct quic_data *quic_token(const struct sock *sk)
{
return &quic_sk(sk)->token;
--
2.47.1