Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/include/net/mptcp.h b/include/net/mptcp.h
new file mode 100644
index 0000000..753ba7e
--- /dev/null
+++ b/include/net/mptcp.h
@@ -0,0 +1,221 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Multipath TCP
+ *
+ * Copyright (c) 2017 - 2019, Intel Corporation.
+ */
+
+#ifndef __NET_MPTCP_H
+#define __NET_MPTCP_H
+
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+#include <linux/types.h>
+
+struct seq_file;
+
+/* MPTCP sk_buff extension data */
+struct mptcp_ext {
+	union {
+		u64	data_ack;
+		u32	data_ack32;
+	};
+	u64		data_seq;
+	u32		subflow_seq;
+	u16		data_len;
+	u8		use_map:1,
+			dsn64:1,
+			data_fin:1,
+			use_ack:1,
+			ack64:1,
+			mpc_map:1,
+			__unused:2;
+	/* one byte hole */
+};
+
+struct mptcp_out_options {
+#if IS_ENABLED(CONFIG_MPTCP)
+	u16 suboptions;
+	u64 sndr_key;
+	u64 rcvr_key;
+	union {
+		struct in_addr addr;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+		struct in6_addr addr6;
+#endif
+	};
+	u8 addr_id;
+	u64 ahmac;
+	u8 rm_id;
+	u8 join_id;
+	u8 backup;
+	u32 nonce;
+	u64 thmac;
+	u32 token;
+	u8 hmac[20];
+	struct mptcp_ext ext_copy;
+#endif
+};
+
+#ifdef CONFIG_MPTCP
+extern struct request_sock_ops mptcp_subflow_request_sock_ops;
+
+void mptcp_init(void);
+
+static inline bool sk_is_mptcp(const struct sock *sk)
+{
+	return tcp_sk(sk)->is_mptcp;
+}
+
+static inline bool rsk_is_mptcp(const struct request_sock *req)
+{
+	return tcp_rsk(req)->is_mptcp;
+}
+
+static inline bool rsk_drop_req(const struct request_sock *req)
+{
+	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
+}
+
+void mptcp_space(const struct sock *ssk, int *space, int *full_space);
+bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
+		       unsigned int *size, struct mptcp_out_options *opts);
+bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
+			  struct mptcp_out_options *opts);
+bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
+			       unsigned int *size, unsigned int remaining,
+			       struct mptcp_out_options *opts);
+void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
+
+void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts);
+
+/* move the skb extension owership, with the assumption that 'to' is
+ * newly allocated
+ */
+static inline void mptcp_skb_ext_move(struct sk_buff *to,
+				      struct sk_buff *from)
+{
+	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
+		return;
+
+	if (WARN_ON_ONCE(to->active_extensions))
+		skb_ext_put(to);
+
+	to->active_extensions = from->active_extensions;
+	to->extensions = from->extensions;
+	from->active_extensions = 0;
+}
+
+static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
+				     const struct mptcp_ext *from_ext)
+{
+	/* MPTCP always clears the ext when adding it to the skb, so
+	 * holes do not bother us here
+	 */
+	return !from_ext ||
+	       (to_ext && from_ext &&
+	        !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
+}
+
+/* check if skbs can be collapsed.
+ * MPTCP collapse is allowed if neither @to or @from carry an mptcp data
+ * mapping, or if the extension of @to is the same as @from.
+ * Collapsing is not possible if @to lacks an extension, but @from carries one.
+ */
+static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
+					  const struct sk_buff *from)
+{
+	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
+				 skb_ext_find(from, SKB_EXT_MPTCP));
+}
+
+void mptcp_seq_show(struct seq_file *seq);
+int mptcp_subflow_init_cookie_req(struct request_sock *req,
+				  const struct sock *sk_listener,
+				  struct sk_buff *skb);
+#else
+
+static inline void mptcp_init(void)
+{
+}
+
+static inline bool sk_is_mptcp(const struct sock *sk)
+{
+	return false;
+}
+
+static inline bool rsk_is_mptcp(const struct request_sock *req)
+{
+	return false;
+}
+
+static inline bool rsk_drop_req(const struct request_sock *req)
+{
+	return false;
+}
+
+static inline void mptcp_parse_option(const struct sk_buff *skb,
+				      const unsigned char *ptr, int opsize,
+				      struct tcp_options_received *opt_rx)
+{
+}
+
+static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
+				     unsigned int *size,
+				     struct mptcp_out_options *opts)
+{
+	return false;
+}
+
+static inline bool mptcp_synack_options(const struct request_sock *req,
+					unsigned int *size,
+					struct mptcp_out_options *opts)
+{
+	return false;
+}
+
+static inline bool mptcp_established_options(struct sock *sk,
+					     struct sk_buff *skb,
+					     unsigned int *size,
+					     unsigned int remaining,
+					     struct mptcp_out_options *opts)
+{
+	return false;
+}
+
+static inline void mptcp_incoming_options(struct sock *sk,
+					  struct sk_buff *skb)
+{
+}
+
+static inline void mptcp_skb_ext_move(struct sk_buff *to,
+				      const struct sk_buff *from)
+{
+}
+
+static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
+					  const struct sk_buff *from)
+{
+	return true;
+}
+
+static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
+static inline void mptcp_seq_show(struct seq_file *seq) { }
+
+static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
+						const struct sock *sk_listener,
+						struct sk_buff *skb)
+{
+	return 0; /* TCP fallback */
+}
+#endif /* CONFIG_MPTCP */
+
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+int mptcpv6_init(void);
+void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
+#elif IS_ENABLED(CONFIG_IPV6)
+static inline int mptcpv6_init(void) { return 0; }
+static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
+#endif
+
+#endif /* __NET_MPTCP_H */