Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 239 insertions, 0 deletions

diff --git a/include/net/request_sock.h b/include/net/request_sock.h
new file mode 100644
index 000000000..29e41ff3e
--- /dev/null
+++ b/include/net/request_sock.h
@@ -0,0 +1,239 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * NET		Generic infrastructure for Network protocols.
+ *
+ *		Definitions for request_sock
+ *
+ * Authors:	Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * 		From code originally in include/net/tcp.h
+ */
+#ifndef _REQUEST_SOCK_H
+#define _REQUEST_SOCK_H
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/bug.h>
+#include <linux/refcount.h>
+
+#include <net/sock.h>
+
+struct request_sock;
+struct sk_buff;
+struct dst_entry;
+struct proto;
+
+struct request_sock_ops {
+	int		family;
+	unsigned int	obj_size;
+	struct kmem_cache	*slab;
+	char		*slab_name;
+	int		(*rtx_syn_ack)(const struct sock *sk,
+				       struct request_sock *req);
+	void		(*send_ack)(const struct sock *sk, struct sk_buff *skb,
+				    struct request_sock *req);
+	void		(*send_reset)(const struct sock *sk,
+				      struct sk_buff *skb);
+	void		(*destructor)(struct request_sock *req);
+	void		(*syn_ack_timeout)(const struct request_sock *req);
+};
+
+int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req);
+
+struct saved_syn {
+	u32 mac_hdrlen;
+	u32 network_hdrlen;
+	u32 tcp_hdrlen;
+	u8 data[];
+};
+
+/* struct request_sock - mini sock to represent a connection request
+ */
+struct request_sock {
+	struct sock_common		__req_common;
+#define rsk_refcnt			__req_common.skc_refcnt
+#define rsk_hash			__req_common.skc_hash
+#define rsk_listener			__req_common.skc_listener
+#define rsk_window_clamp		__req_common.skc_window_clamp
+#define rsk_rcv_wnd			__req_common.skc_rcv_wnd
+
+	struct request_sock		*dl_next;
+	u16				mss;
+	u8				num_retrans; /* number of retransmits */
+	u8				syncookie:1; /* syncookie: encode tcpopts in timestamp */
+	u8				num_timeout:7; /* number of timeouts */
+	u32				ts_recent;
+	struct timer_list		rsk_timer;
+	const struct request_sock_ops	*rsk_ops;
+	struct sock			*sk;
+	struct saved_syn		*saved_syn;
+	u32				secid;
+	u32				peer_secid;
+};
+
+static inline struct request_sock *inet_reqsk(const struct sock *sk)
+{
+	return (struct request_sock *)sk;
+}
+
+static inline struct sock *req_to_sk(struct request_sock *req)
+{
+	return (struct sock *)req;
+}
+
+static inline struct request_sock *
+reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener,
+	    bool attach_listener)
+{
+	struct request_sock *req;
+
+	req = kmem_cache_alloc(ops->slab, GFP_ATOMIC | __GFP_NOWARN);
+	if (!req)
+		return NULL;
+	req->rsk_listener = NULL;
+	if (attach_listener) {
+		if (unlikely(!refcount_inc_not_zero(&sk_listener->sk_refcnt))) {
+			kmem_cache_free(ops->slab, req);
+			return NULL;
+		}
+		req->rsk_listener = sk_listener;
+	}
+	req->rsk_ops = ops;
+	req_to_sk(req)->sk_prot = sk_listener->sk_prot;
+	sk_node_init(&req_to_sk(req)->sk_node);
+	sk_tx_queue_clear(req_to_sk(req));
+	req->saved_syn = NULL;
+	req->num_timeout = 0;
+	req->num_retrans = 0;
+	req->sk = NULL;
+	refcount_set(&req->rsk_refcnt, 0);
+
+	return req;
+}
+
+static inline void __reqsk_free(struct request_sock *req)
+{
+	req->rsk_ops->destructor(req);
+	if (req->rsk_listener)
+		sock_put(req->rsk_listener);
+	kfree(req->saved_syn);
+	kmem_cache_free(req->rsk_ops->slab, req);
+}
+
+static inline void reqsk_free(struct request_sock *req)
+{
+	WARN_ON_ONCE(refcount_read(&req->rsk_refcnt) != 0);
+	__reqsk_free(req);
+}
+
+static inline void reqsk_put(struct request_sock *req)
+{
+	if (refcount_dec_and_test(&req->rsk_refcnt))
+		reqsk_free(req);
+}
+
+/*
+ * For a TCP Fast Open listener -
+ *	lock - protects the access to all the reqsk, which is co-owned by
+ *		the listener and the child socket.
+ *	qlen - pending TFO requests (still in TCP_SYN_RECV).
+ *	max_qlen - max TFO reqs allowed before TFO is disabled.
+ *
+ *	XXX (TFO) - ideally these fields can be made as part of "listen_sock"
+ *	structure above. But there is some implementation difficulty due to
+ *	listen_sock being part of request_sock_queue hence will be freed when
+ *	a listener is stopped. But TFO related fields may continue to be
+ *	accessed even after a listener is closed, until its sk_refcnt drops
+ *	to 0 implying no more outstanding TFO reqs. One solution is to keep
+ *	listen_opt around until	sk_refcnt drops to 0. But there is some other
+ *	complexity that needs to be resolved. E.g., a listener can be disabled
+ *	temporarily through shutdown()->tcp_disconnect(), and re-enabled later.
+ */
+struct fastopen_queue {
+	struct request_sock	*rskq_rst_head; /* Keep track of past TFO */
+	struct request_sock	*rskq_rst_tail; /* requests that caused RST.
+						 * This is part of the defense
+						 * against spoofing attack.
+						 */
+	spinlock_t	lock;
+	int		qlen;		/* # of pending (TCP_SYN_RECV) reqs */
+	int		max_qlen;	/* != 0 iff TFO is currently enabled */
+
+	struct tcp_fastopen_context __rcu *ctx; /* cipher context for cookie */
+};
+
+/** struct request_sock_queue - queue of request_socks
+ *
+ * @rskq_accept_head - FIFO head of established children
+ * @rskq_accept_tail - FIFO tail of established children
+ * @rskq_defer_accept - User waits for some data after accept()
+ *
+ */
+struct request_sock_queue {
+	spinlock_t		rskq_lock;
+	u8			rskq_defer_accept;
+
+	u32			synflood_warned;
+	atomic_t		qlen;
+	atomic_t		young;
+
+	struct request_sock	*rskq_accept_head;
+	struct request_sock	*rskq_accept_tail;
+	struct fastopen_queue	fastopenq;  /* Check max_qlen != 0 to determine
+					     * if TFO is enabled.
+					     */
+};
+
+void reqsk_queue_alloc(struct request_sock_queue *queue);
+
+void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req,
+			   bool reset);
+
+static inline bool reqsk_queue_empty(const struct request_sock_queue *queue)
+{
+	return READ_ONCE(queue->rskq_accept_head) == NULL;
+}
+
+static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue,
+						      struct sock *parent)
+{
+	struct request_sock *req;
+
+	spin_lock_bh(&queue->rskq_lock);
+	req = queue->rskq_accept_head;
+	if (req) {
+		sk_acceptq_removed(parent);
+		WRITE_ONCE(queue->rskq_accept_head, req->dl_next);
+		if (queue->rskq_accept_head == NULL)
+			queue->rskq_accept_tail = NULL;
+	}
+	spin_unlock_bh(&queue->rskq_lock);
+	return req;
+}
+
+static inline void reqsk_queue_removed(struct request_sock_queue *queue,
+				       const struct request_sock *req)
+{
+	if (req->num_timeout == 0)
+		atomic_dec(&queue->young);
+	atomic_dec(&queue->qlen);
+}
+
+static inline void reqsk_queue_added(struct request_sock_queue *queue)
+{
+	atomic_inc(&queue->young);
+	atomic_inc(&queue->qlen);
+}
+
+static inline int reqsk_queue_len(const struct request_sock_queue *queue)
+{
+	return atomic_read(&queue->qlen);
+}
+
+static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
+{
+	return atomic_read(&queue->young);
+}
+
+#endif /* _REQUEST_SOCK_H */