[PATCH net-next v10 05/15] quic: provide quic.h header files for kernel and userspace

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
exposes quic_do_get/setsockopt() to handle QUIC socket options directly
for kernel subsystems.

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 <[email protected]>
Signed-off-by: Stefan Metzmacher <[email protected]>
Signed-off-by: Thomas Dreibholz <[email protected]>
Signed-off-by: Xin Long <[email protected]>
Acked-by: Paolo Abeni <[email protected]>
---
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.
v4:
  - Use MSG_QUIC_ prefix for MSG_* flags to avoid conflicts with other
    protocols, such as MSG_NOTIFICATION in SCTP (reported by Thomas).
  - Remove QUIC_CONG_ALG_CUBIC; only NEW RENO congestion control is
    supported in this version.
v5:
  - Add include/linux/quic.h and include/uapi/linux/quic.h to the
    QUIC PROTOCOL entry in MAINTAINERS.
v6:
  - Fix the copy/pasted the uAPI path for SCTP to the QUIC entry (noted
    by Jakub).
v7:
  - Expose quic_do_get/setsockopt() instead of quic_kernel_get/setsockopt()
    (suggested by Paolo).
v10:
  - Fix typo: 'extented' -> 'extended' (noted by AI review).
  - Add comment for inclusion of sys/socket.h in uapi quic.h.
  - Add uses-libc += linux/quic.h in usr/include/Makefile to fix the new
    build error.
  - Delete config from struct quic_sock, its members will be split into
    other subcomponents in the future patches.
  - Add explicit reserved fields to multiple structs to account for
    implicit padding and ensure UAPI stability.
  - Expand reserved fields in struct transport_param and config, handshake
    and stream_info to allow future extensions without breaking the UAPI.
---
 MAINTAINERS               |   2 +
 include/linux/quic.h      |  20 ++++
 include/uapi/linux/quic.h | 242 ++++++++++++++++++++++++++++++++++++++
 net/quic/socket.c         |  32 ++++-
 net/quic/socket.h         |   1 +
 usr/include/Makefile      |   1 +
 6 files changed, 296 insertions(+), 2 deletions(-)
 create mode 100644 include/linux/quic.h
 create mode 100644 include/uapi/linux/quic.h

diff --git a/MAINTAINERS b/MAINTAINERS
index f1dfc2239978..36aa61f29aab 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21920,6 +21920,8 @@ M:	Xin Long <[email protected]>
 L:	[email protected]
 S:	Maintained
 W:	https://github.com/lxin/quic
+F:	include/linux/quic.h
+F:	include/uapi/linux/quic.h
 F:	net/quic/
 
 RADEON and AMDGPU DRM DRIVERS
diff --git a/include/linux/quic.h b/include/linux/quic.h
new file mode 100644
index 000000000000..c246f6349f9c
--- /dev/null
+++ b/include/linux/quic.h
@@ -0,0 +1,20 @@
+/* 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 <[email protected]>
+ */
+
+#ifndef _LINUX_QUIC_H
+#define _LINUX_QUIC_H
+
+#include <linux/sockptr.h>
+#include <uapi/linux/quic.h>
+
+int quic_do_setsockopt(struct sock *sk, int optname, sockptr_t optval, unsigned int optlen);
+int quic_do_getsockopt(struct sock *sk, int optname, sockptr_t optval, sockptr_t optlen);
+
+#endif
diff --git a/include/uapi/linux/quic.h b/include/uapi/linux/quic.h
new file mode 100644
index 000000000000..19e0f0d957fe
--- /dev/null
+++ b/include/uapi/linux/quic.h
@@ -0,0 +1,242 @@
+/* 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 <[email protected]>
+ */
+
+#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> /* for MSG_* flags */
+#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_QUIC_STREAM_NEW		= MSG_SYN,
+	MSG_QUIC_STREAM_FIN		= MSG_FIN,
+	MSG_QUIC_STREAM_UNI		= MSG_CONFIRM,
+	MSG_QUIC_STREAM_DONTWAIT	= MSG_WAITFORONE,
+	MSG_QUIC_STREAM_SNDBLOCK	= MSG_ERRQUEUE,
+
+	/* extended flags for msg_flags */
+	MSG_QUIC_DATAGRAM		= MSG_RST,
+	MSG_QUIC_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;
+	__u8	reserved[7];
+};
+
+struct quic_stream_info {
+	__s64	stream_id;
+	__u32	stream_flags;
+	__u32	reserved;
+};
+
+/* 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[4];
+};
+
+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[43];
+};
+
+struct quic_crypto_secret {
+	__u8	send;  /* send or recv */
+	__u8	level; /* crypto level */
+	__u16	reserved;
+	__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_MAX,
+};
+
+struct quic_errinfo {
+	__s64	stream_id;
+	__u32	errcode;
+	__u32	reserved;
+};
+
+struct quic_connection_id_info {
+	__u8	dest;
+	__u8	reserved[3];
+	__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;
+	__u8	reserved[3];
+	__u32	errcode;
+	__u64	finalsz;
+};
+
+struct quic_stream_max_data {
+	__s64	id;
+	__u64	max_data;
+};
+
+struct quic_connection_close {
+	__u32	errcode;
+	__u8	frame;
+	__u8	reserved[3];
+	__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 1ef8a7932932..72483b561820 100644
--- a/net/quic/socket.c
+++ b/net/quic/socket.c
@@ -104,10 +104,24 @@ static void quic_close(struct sock *sk, long timeout)
 	sk_common_release(sk);
 }
 
-static int quic_do_setsockopt(struct sock *sk, int optname, sockptr_t optval, unsigned int optlen)
+/**
+ * quic_do_setsockopt - set a QUIC socket option
+ * @sk: socket to configure
+ * @optname: option name (QUIC-level)
+ * @optval: user buffer containing the option value
+ * @optlen: size of the option value
+ *
+ * Sets a QUIC socket option on a given socket.
+ *
+ * Return:
+ * - On success, 0 is returned.
+ * - On error, a negative error value is returned.
+ */
+int quic_do_setsockopt(struct sock *sk, int optname, sockptr_t optval, unsigned int optlen)
 {
 	return -EOPNOTSUPP;
 }
+EXPORT_SYMBOL_GPL(quic_do_setsockopt);
 
 static int quic_setsockopt(struct sock *sk, int level, int optname,
 			   sockptr_t optval, unsigned int optlen)
@@ -118,10 +132,24 @@ static int quic_setsockopt(struct sock *sk, int level, int optname,
 	return quic_do_setsockopt(sk, optname, optval, optlen);
 }
 
-static int quic_do_getsockopt(struct sock *sk, int optname, sockptr_t optval, sockptr_t optlen)
+/**
+ * quic_do_getsockopt - get a QUIC socket option
+ * @sk: socket to query
+ * @optname: option name (QUIC-level)
+ * @optval: user buffer to receive the option value
+ * @optlen: in/out parameter for buffer size; updated with actual length on return
+ *
+ * Gets a QUIC socket option from a given socket.
+ *
+ * Return:
+ * - On success, 0 is returned.
+ * - On error, a negative error value is returned.
+ */
+int quic_do_getsockopt(struct sock *sk, int optname, sockptr_t optval, sockptr_t optlen)
 {
 	return -EOPNOTSUPP;
 }
+EXPORT_SYMBOL_GPL(quic_do_getsockopt);
 
 static int quic_getsockopt(struct sock *sk, int level, int optname,
 			   char __user *optval, int __user *optlen)
diff --git a/net/quic/socket.h b/net/quic/socket.h
index 0aa642e3b0ae..61df0c5867be 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"
diff --git a/usr/include/Makefile b/usr/include/Makefile
index 6d86a53c6f0a..a0442e4d77da 100644
--- a/usr/include/Makefile
+++ b/usr/include/Makefile
@@ -120,6 +120,7 @@ uses-libc += linux/netfilter_ipv4.h
 uses-libc += linux/netfilter_ipv4/ip_tables.h
 uses-libc += linux/netfilter_ipv6.h
 uses-libc += linux/netfilter_ipv6/ip6_tables.h
+uses-libc += linux/quic.h
 uses-libc += linux/route.h
 uses-libc += linux/shm.h
 uses-libc += linux/soundcard.h
-- 
2.47.1