131 struct tcp_sock {  struct
133 	struct inet_connection_sock	inet_conn;
134 	u16	tcp_header_len;	/* Bytes of tcp header to send		*/
135 	u16	gso_segs;	/* Max number of segs per GSO packet	*/
141 	__be32	pred_flags;
148 	u64	bytes_received;	/* RFC4898 tcpEStatsAppHCThruOctetsReceived
152  	u32	rcv_nxt;	/* What we want to receive next 	*/
153 	u32	copied_seq;	/* Head of yet unread data		*/
154 	u32	rcv_wup;	/* rcv_nxt on last window update sent	*/
155  	u32	snd_nxt;	/* Next sequence we send		*/
157 	u64	bytes_acked;	/* RFC4898 tcpEStatsAppHCThruOctetsAcked
161 	struct u64_stats_sync syncp; /* protects 64bit vars (cf tcp_get_info()) */
163  	u32	snd_una;	/* First byte we want an ack for	*/
164  	u32	snd_sml;	/* Last byte of the most recently transmitted small packet */
165 	u32	rcv_tstamp;	/* timestamp of last received ACK (for keepalives) */
166 	u32	lsndtime;	/* timestamp of last sent data packet (for restart window) */
167 	u32	last_oow_ack_time;  /* timestamp of last out-of-window ACK */
169 	u32	tsoffset;	/* timestamp offset */
171 	struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
172 	unsigned long	tsq_flags;
175 	struct {
181 	} ucopy;
183 	u32	snd_wl1;	/* Sequence for window update		*/
184 	u32	snd_wnd;	/* The window we expect to receive	*/
185 	u32	max_window;	/* Maximal window ever seen from peer	*/
186 	u32	mss_cache;	/* Cached effective mss, not including SACKS */
188 	u32	window_clamp;	/* Maximal window to advertise		*/
189 	u32	rcv_ssthresh;	/* Current window clamp			*/
191 	u16	advmss;		/* Advertised MSS			*/
192 	u8	unused;
193 	u8	nonagle     : 4,/* Disable Nagle algorithm?             */
194 		thin_lto    : 1,/* Use linear timeouts for thin streams */
195 		thin_dupack : 1,/* Fast retransmit on first dupack      */
196 		repair      : 1,
197 		frto        : 1;/* F-RTO (RFC5682) activated in CA_Loss */
198 	u8	repair_queue;
199 	u8	do_early_retrans:1,/* Enable RFC5827 early-retransmit  */
200 		syn_data:1,	/* SYN includes data */
201 		syn_fastopen:1,	/* SYN includes Fast Open option */
202 		syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
203 		syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
204 		is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
205 	u32	tlp_high_seq;	/* snd_nxt at the time of TLP retransmit. */
208 	u32	srtt_us;	/* smoothed round trip time << 3 in usecs */
209 	u32	mdev_us;	/* medium deviation			*/
210 	u32	mdev_max_us;	/* maximal mdev for the last rtt period	*/
211 	u32	rttvar_us;	/* smoothed mdev_max			*/
212 	u32	rtt_seq;	/* sequence number to update rttvar	*/
214 	u32	packets_out;	/* Packets which are "in flight"	*/
215 	u32	retrans_out;	/* Retransmitted packets out		*/
216 	u32	max_packets_out;  /* max packets_out in last window */
217 	u32	max_packets_seq;  /* right edge of max_packets_out flight */
219 	u16	urg_data;	/* Saved octet of OOB data and control flags */
220 	u8	ecn_flags;	/* ECN status bits.			*/
221 	u8	keepalive_probes; /* num of allowed keep alive probes	*/
222 	u32	reordering;	/* Packet reordering metric.		*/
223 	u32	snd_up;		/* Urgent pointer		*/
228 	struct tcp_options_received rx_opt;
233  	u32	snd_ssthresh;	/* Slow start size threshold		*/
234  	u32	snd_cwnd;	/* Sending congestion window		*/
235 	u32	snd_cwnd_cnt;	/* Linear increase counter		*/
236 	u32	snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
237 	u32	snd_cwnd_used;
238 	u32	snd_cwnd_stamp;
239 	u32	prior_cwnd;	/* Congestion window at start of Recovery. */
240 	u32	prr_delivered;	/* Number of newly delivered packets to
242 	u32	prr_out;	/* Total number of pkts sent during Recovery. */
244  	u32	rcv_wnd;	/* Current receiver window		*/
245 	u32	write_seq;	/* Tail(+1) of data held in tcp send buffer */
246 	u32	notsent_lowat;	/* TCP_NOTSENT_LOWAT */
247 	u32	pushed_seq;	/* Last pushed seq, required to talk to windows */
248 	u32	lost_out;	/* Lost packets			*/
249 	u32	sacked_out;	/* SACK'd packets			*/
250 	u32	fackets_out;	/* FACK'd packets			*/
253 	struct sk_buff* lost_skb_hint;
254 	struct sk_buff *retransmit_skb_hint;
259 	struct sk_buff_head	out_of_order_queue;
262 	struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
263 	struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
265 	struct tcp_sack_block recv_sack_cache[4];
267 	struct sk_buff *highest_sack;   /* skb just after the highest
273 	int     lost_cnt_hint;
274 	u32     retransmit_high;	/* L-bits may be on up to this seqno */
276 	u32	lost_retrans_low;	/* Sent seq after any rxmit (lowest) */
278 	u32	prior_ssthresh; /* ssthresh saved at recovery start	*/
279 	u32	high_seq;	/* snd_nxt at onset of congestion	*/
281 	u32	retrans_stamp;	/* Timestamp of the last retransmit,
284 	u32	undo_marker;	/* snd_una upon a new recovery episode. */
285 	int	undo_retrans;	/* number of undoable retransmissions. */
286 	u32	total_retrans;	/* Total retransmits for entire connection */
288 	u32	urg_seq;	/* Seq of received urgent pointer */
289 	unsigned int		keepalive_time;	  /* time before keep alive takes place */
290 	unsigned int		keepalive_intvl;  /* time interval between keep alive probes */
292 	int			linger2;
295 	struct {
319 	const struct tcp_sock_af_ops	*af_specific;  argument
344 static inline struct tcp_sock *tcp_sk(const struct sock *sk)  in tcp_sk()  argument