Initial import

1 files changed, 414 insertions, 0 deletions

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
new file mode 100644
index 000000000..f62b548ac
--- /dev/null
+++ b/include/linux/tcp.h
@@ -0,0 +1,414 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Definitions for the TCP protocol.
+ *
+ * Version:	@(#)tcp.h	1.0.2	04/28/93
+ *
+ * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#ifndef _LINUX_TCP_H
+#define _LINUX_TCP_H
+
+
+#include <linux/skbuff.h>
+#include <linux/cryptohash.h>
+#include <net/sock.h>
+#include <net/inet_connection_sock.h>
+#include <net/inet_timewait_sock.h>
+#include <uapi/linux/tcp.h>
+
+static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb)
+{
+	return (struct tcphdr *)skb_transport_header(skb);
+}
+
+static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)
+{
+	return tcp_hdr(skb)->doff * 4;
+}
+
+static inline struct tcphdr *inner_tcp_hdr(const struct sk_buff *skb)
+{
+	return (struct tcphdr *)skb_inner_transport_header(skb);
+}
+
+static inline unsigned int inner_tcp_hdrlen(const struct sk_buff *skb)
+{
+	return inner_tcp_hdr(skb)->doff * 4;
+}
+
+static inline unsigned int tcp_optlen(const struct sk_buff *skb)
+{
+	return (tcp_hdr(skb)->doff - 5) * 4;
+}
+
+/* TCP Fast Open */
+#define TCP_FASTOPEN_COOKIE_MIN	4	/* Min Fast Open Cookie size in bytes */
+#define TCP_FASTOPEN_COOKIE_MAX	16	/* Max Fast Open Cookie size in bytes */
+#define TCP_FASTOPEN_COOKIE_SIZE 8	/* the size employed by this impl. */
+
+/* TCP Fast Open Cookie as stored in memory */
+struct tcp_fastopen_cookie {
+	s8	len;
+	u8	val[TCP_FASTOPEN_COOKIE_MAX];
+	bool	exp;	/* In RFC6994 experimental option format */
+};
+
+/* This defines a selective acknowledgement block. */
+struct tcp_sack_block_wire {
+	__be32	start_seq;
+	__be32	end_seq;
+};
+
+struct tcp_sack_block {
+	u32	start_seq;
+	u32	end_seq;
+};
+
+/*These are used to set the sack_ok field in struct tcp_options_received */
+#define TCP_SACK_SEEN     (1 << 0)   /*1 = peer is SACK capable, */
+#define TCP_FACK_ENABLED  (1 << 1)   /*1 = FACK is enabled locally*/
+#define TCP_DSACK_SEEN    (1 << 2)   /*1 = DSACK was received from peer*/
+
+struct tcp_options_received {
+/*	PAWS/RTTM data	*/
+	long	ts_recent_stamp;/* Time we stored ts_recent (for aging) */
+	u32	ts_recent;	/* Time stamp to echo next		*/
+	u32	rcv_tsval;	/* Time stamp value             	*/
+	u32	rcv_tsecr;	/* Time stamp echo reply        	*/
+	u16 	saw_tstamp : 1,	/* Saw TIMESTAMP on last packet		*/
+		tstamp_ok : 1,	/* TIMESTAMP seen on SYN packet		*/
+		dsack : 1,	/* D-SACK is scheduled			*/
+		wscale_ok : 1,	/* Wscale seen on SYN packet		*/
+		sack_ok : 4,	/* SACK seen on SYN packet		*/
+		snd_wscale : 4,	/* Window scaling received from sender	*/
+		rcv_wscale : 4;	/* Window scaling to send to receiver	*/
+	u8	num_sacks;	/* Number of SACK blocks		*/
+	u16	user_mss;	/* mss requested by user in ioctl	*/
+	u16	mss_clamp;	/* Maximal mss, negotiated at connection setup */
+};
+
+static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
+{
+	rx_opt->tstamp_ok = rx_opt->sack_ok = 0;
+	rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
+}
+
+/* This is the max number of SACKS that we'll generate and process. It's safe
+ * to increase this, although since:
+ *   size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8)
+ * only four options will fit in a standard TCP header */
+#define TCP_NUM_SACKS 4
+
+struct tcp_request_sock_ops;
+
+struct tcp_request_sock {
+	struct inet_request_sock 	req;
+	const struct tcp_request_sock_ops *af_specific;
+	bool				tfo_listener;
+	u32				rcv_isn;
+	u32				snt_isn;
+	u32				snt_synack; /* synack sent time */
+	u32				last_oow_ack_time; /* last SYNACK */
+	u32				rcv_nxt; /* the ack # by SYNACK. For
+						  * FastOpen it's the seq#
+						  * after data-in-SYN.
+						  */
+};
+
+static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
+{
+	return (struct tcp_request_sock *)req;
+}
+
+struct tcp_sock {
+	/* inet_connection_sock has to be the first member of tcp_sock */
+	struct inet_connection_sock	inet_conn;
+	u16	tcp_header_len;	/* Bytes of tcp header to send		*/
+	u16	gso_segs;	/* Max number of segs per GSO packet	*/
+
+/*
+ *	Header prediction flags
+ *	0x5?10 << 16 + snd_wnd in net byte order
+ */
+	__be32	pred_flags;
+
+/*
+ *	RFC793 variables by their proper names. This means you can
+ *	read the code and the spec side by side (and laugh ...)
+ *	See RFC793 and RFC1122. The RFC writes these in capitals.
+ */
+	u64	bytes_received;	/* RFC4898 tcpEStatsAppHCThruOctetsReceived
+				 * sum(delta(rcv_nxt)), or how many bytes
+				 * were acked.
+				 */
+ 	u32	rcv_nxt;	/* What we want to receive next 	*/
+	u32	copied_seq;	/* Head of yet unread data		*/
+	u32	rcv_wup;	/* rcv_nxt on last window update sent	*/
+ 	u32	snd_nxt;	/* Next sequence we send		*/
+
+	u64	bytes_acked;	/* RFC4898 tcpEStatsAppHCThruOctetsAcked
+				 * sum(delta(snd_una)), or how many bytes
+				 * were acked.
+				 */
+	struct u64_stats_sync syncp; /* protects 64bit vars (cf tcp_get_info()) */
+
+ 	u32	snd_una;	/* First byte we want an ack for	*/
+ 	u32	snd_sml;	/* Last byte of the most recently transmitted small packet */
+	u32	rcv_tstamp;	/* timestamp of last received ACK (for keepalives) */
+	u32	lsndtime;	/* timestamp of last sent data packet (for restart window) */
+	u32	last_oow_ack_time;  /* timestamp of last out-of-window ACK */
+
+	u32	tsoffset;	/* timestamp offset */
+
+	struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
+	unsigned long	tsq_flags;
+
+	/* Data for direct copy to user */
+	struct {
+		struct sk_buff_head	prequeue;
+		struct task_struct	*task;
+		struct msghdr		*msg;
+		int			memory;
+		int			len;
+	} ucopy;
+
+	u32	snd_wl1;	/* Sequence for window update		*/
+	u32	snd_wnd;	/* The window we expect to receive	*/
+	u32	max_window;	/* Maximal window ever seen from peer	*/
+	u32	mss_cache;	/* Cached effective mss, not including SACKS */
+
+	u32	window_clamp;	/* Maximal window to advertise		*/
+	u32	rcv_ssthresh;	/* Current window clamp			*/
+
+	u16	advmss;		/* Advertised MSS			*/
+	u8	unused;
+	u8	nonagle     : 4,/* Disable Nagle algorithm?             */
+		thin_lto    : 1,/* Use linear timeouts for thin streams */
+		thin_dupack : 1,/* Fast retransmit on first dupack      */
+		repair      : 1,
+		frto        : 1;/* F-RTO (RFC5682) activated in CA_Loss */
+	u8	repair_queue;
+	u8	do_early_retrans:1,/* Enable RFC5827 early-retransmit  */
+		syn_data:1,	/* SYN includes data */
+		syn_fastopen:1,	/* SYN includes Fast Open option */
+		syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
+		syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
+		is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
+	u32	tlp_high_seq;	/* snd_nxt at the time of TLP retransmit. */
+
+/* RTT measurement */
+	u32	srtt_us;	/* smoothed round trip time << 3 in usecs */
+	u32	mdev_us;	/* medium deviation			*/
+	u32	mdev_max_us;	/* maximal mdev for the last rtt period	*/
+	u32	rttvar_us;	/* smoothed mdev_max			*/
+	u32	rtt_seq;	/* sequence number to update rttvar	*/
+
+	u32	packets_out;	/* Packets which are "in flight"	*/
+	u32	retrans_out;	/* Retransmitted packets out		*/
+	u32	max_packets_out;  /* max packets_out in last window */
+	u32	max_packets_seq;  /* right edge of max_packets_out flight */
+
+	u16	urg_data;	/* Saved octet of OOB data and control flags */
+	u8	ecn_flags;	/* ECN status bits.			*/
+	u8	keepalive_probes; /* num of allowed keep alive probes	*/
+	u32	reordering;	/* Packet reordering metric.		*/
+	u32	snd_up;		/* Urgent pointer		*/
+
+/*
+ *      Options received (usually on last packet, some only on SYN packets).
+ */
+	struct tcp_options_received rx_opt;
+
+/*
+ *	Slow start and congestion control (see also Nagle, and Karn & Partridge)
+ */
+ 	u32	snd_ssthresh;	/* Slow start size threshold		*/
+ 	u32	snd_cwnd;	/* Sending congestion window		*/
+	u32	snd_cwnd_cnt;	/* Linear increase counter		*/
+	u32	snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
+	u32	snd_cwnd_used;
+	u32	snd_cwnd_stamp;
+	u32	prior_cwnd;	/* Congestion window at start of Recovery. */
+	u32	prr_delivered;	/* Number of newly delivered packets to
+				 * receiver in Recovery. */
+	u32	prr_out;	/* Total number of pkts sent during Recovery. */
+
+ 	u32	rcv_wnd;	/* Current receiver window		*/
+	u32	write_seq;	/* Tail(+1) of data held in tcp send buffer */
+	u32	notsent_lowat;	/* TCP_NOTSENT_LOWAT */
+	u32	pushed_seq;	/* Last pushed seq, required to talk to windows */
+	u32	lost_out;	/* Lost packets			*/
+	u32	sacked_out;	/* SACK'd packets			*/
+	u32	fackets_out;	/* FACK'd packets			*/
+
+	/* from STCP, retrans queue hinting */
+	struct sk_buff* lost_skb_hint;
+	struct sk_buff *retransmit_skb_hint;
+
+	/* OOO segments go in this list. Note that socket lock must be held,
+	 * as we do not use sk_buff_head lock.
+	 */
+	struct sk_buff_head	out_of_order_queue;
+
+	/* SACKs data, these 2 need to be together (see tcp_options_write) */
+	struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
+	struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
+
+	struct tcp_sack_block recv_sack_cache[4];
+
+	struct sk_buff *highest_sack;   /* skb just after the highest
+					 * skb with SACKed bit set
+					 * (validity guaranteed only if
+					 * sacked_out > 0)
+					 */
+
+	int     lost_cnt_hint;
+	u32     retransmit_high;	/* L-bits may be on up to this seqno */
+
+	u32	lost_retrans_low;	/* Sent seq after any rxmit (lowest) */
+
+	u32	prior_ssthresh; /* ssthresh saved at recovery start	*/
+	u32	high_seq;	/* snd_nxt at onset of congestion	*/
+
+	u32	retrans_stamp;	/* Timestamp of the last retransmit,
+				 * also used in SYN-SENT to remember stamp of
+				 * the first SYN. */
+	u32	undo_marker;	/* snd_una upon a new recovery episode. */
+	int	undo_retrans;	/* number of undoable retransmissions. */
+	u32	total_retrans;	/* Total retransmits for entire connection */
+
+	u32	urg_seq;	/* Seq of received urgent pointer */
+	unsigned int		keepalive_time;	  /* time before keep alive takes place */
+	unsigned int		keepalive_intvl;  /* time interval between keep alive probes */
+
+	int			linger2;
+
+/* Receiver side RTT estimation */
+	struct {
+		u32	rtt;
+		u32	seq;
+		u32	time;
+	} rcv_rtt_est;
+
+/* Receiver queue space */
+	struct {
+		int	space;
+		u32	seq;
+		u32	time;
+	} rcvq_space;
+
+/* TCP-specific MTU probe information. */
+	struct {
+		u32		  probe_seq_start;
+		u32		  probe_seq_end;
+	} mtu_probe;
+	u32	mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG
+			   * while socket was owned by user.
+			   */
+
+#ifdef CONFIG_TCP_MD5SIG
+/* TCP AF-Specific parts; only used by MD5 Signature support so far */
+	const struct tcp_sock_af_ops	*af_specific;
+
+/* TCP MD5 Signature Option information */
+	struct tcp_md5sig_info	__rcu *md5sig_info;
+#endif
+
+#ifdef CONFIG_TCP_STEALTH
+/* Stealth TCP socket configuration */
+	struct {
+		#define TCP_STEALTH_MODE_AUTH		BIT(0)
+		#define TCP_STEALTH_MODE_INTEGRITY	BIT(1)
+		#define TCP_STEALTH_MODE_INTEGRITY_LEN	BIT(2)
+		u8 mode;
+		u8 secret[MD5_MESSAGE_BYTES];
+		u16 integrity_hash;
+		size_t integrity_len;
+		struct skb_mstamp mstamp;
+		bool saw_tsval;
+	} stealth;
+#endif
+
+/* TCP fastopen related information */
+	struct tcp_fastopen_request *fastopen_req;
+	/* fastopen_rsk points to request_sock that resulted in this big
+	 * socket. Used to retransmit SYNACKs etc.
+	 */
+	struct request_sock *fastopen_rsk;
+};
+
+enum tsq_flags {
+	TSQ_THROTTLED,
+	TSQ_QUEUED,
+	TCP_TSQ_DEFERRED,	   /* tcp_tasklet_func() found socket was owned */
+	TCP_WRITE_TIMER_DEFERRED,  /* tcp_write_timer() found socket was owned */
+	TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */
+	TCP_MTU_REDUCED_DEFERRED,  /* tcp_v{4|6}_err() could not call
+				    * tcp_v{4|6}_mtu_reduced()
+				    */
+};
+
+static inline struct tcp_sock *tcp_sk(const struct sock *sk)
+{
+	return (struct tcp_sock *)sk;
+}
+
+struct tcp_timewait_sock {
+	struct inet_timewait_sock tw_sk;
+	u32			  tw_rcv_nxt;
+	u32			  tw_snd_nxt;
+	u32			  tw_rcv_wnd;
+	u32			  tw_ts_offset;
+	u32			  tw_ts_recent;
+
+	/* The time we sent the last out-of-window ACK: */
+	u32			  tw_last_oow_ack_time;
+
+	long			  tw_ts_recent_stamp;
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_md5sig_key	  *tw_md5_key;
+#endif
+};
+
+static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
+{
+	return (struct tcp_timewait_sock *)sk;
+}
+
+static inline bool tcp_passive_fastopen(const struct sock *sk)
+{
+	return (sk->sk_state == TCP_SYN_RECV &&
+		tcp_sk(sk)->fastopen_rsk != NULL);
+}
+
+extern void tcp_sock_destruct(struct sock *sk);
+
+static inline int fastopen_init_queue(struct sock *sk, int backlog)
+{
+	struct request_sock_queue *queue =
+	    &inet_csk(sk)->icsk_accept_queue;
+
+	if (queue->fastopenq == NULL) {
+		queue->fastopenq = kzalloc(
+		    sizeof(struct fastopen_queue),
+		    sk->sk_allocation);
+		if (queue->fastopenq == NULL)
+			return -ENOMEM;
+
+		sk->sk_destruct = tcp_sock_destruct;
+		spin_lock_init(&queue->fastopenq->lock);
+	}
+	queue->fastopenq->max_qlen = backlog;
+	return 0;
+}
+
+#endif	/* _LINUX_TCP_H */