v4.19.13 snapshot.
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
new file mode 100644
index 0000000..d2c8f28
--- /dev/null
+++ b/include/linux/tcp.h
@@ -0,0 +1,488 @@
+/*
+ * 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/win_minmax.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 tcphdr *th)
+{
+ return th->doff * 4;
+}
+
+static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)
+{
+ return __tcp_hdrlen(tcp_hdr(skb));
+}
+
+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 {
+ union {
+ u8 val[TCP_FASTOPEN_COOKIE_MAX];
+#if IS_ENABLED(CONFIG_IPV6)
+ struct in6_addr addr;
+#endif
+ };
+ s8 len;
+ 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_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/
+
+struct tcp_options_received {
+/* PAWS/RTTM data */
+ int 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 : 3, /* SACK seen on SYN packet */
+ smc_ok : 1, /* SMC 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;
+#if IS_ENABLED(CONFIG_SMC)
+ rx_opt->smc_ok = 0;
+#endif
+}
+
+/* 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;
+ u64 snt_synack; /* first SYNACK sent time */
+ bool tfo_listener;
+ u32 txhash;
+ u32 rcv_isn;
+ u32 snt_isn;
+ u32 ts_off;
+ 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 segs_in; /* RFC4898 tcpEStatsPerfSegsIn
+ * total number of segments in.
+ */
+ u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn
+ * total number of data segments in.
+ */
+ 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 */
+ u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut
+ * The total number of segments sent.
+ */
+ u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut
+ * total number of data segments sent.
+ */
+ u64 bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut
+ * total number of data bytes sent.
+ */
+ u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked
+ * sum(delta(snd_una)), or how many bytes
+ * were acked.
+ */
+ u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups
+ * total number of DSACK blocks received
+ */
+ 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 compressed_ack_rcv_nxt;
+
+ u32 tsoffset; /* timestamp offset */
+
+ struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
+ struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */
+
+ 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 */
+
+ /* Information of the most recently (s)acked skb */
+ struct tcp_rack {
+ u64 mstamp; /* (Re)sent time of the skb */
+ u32 rtt_us; /* Associated RTT */
+ u32 end_seq; /* Ending TCP sequence of the skb */
+ u32 last_delivered; /* tp->delivered at last reo_wnd adj */
+ u8 reo_wnd_steps; /* Allowed reordering window */
+#define TCP_RACK_RECOVERY_THRESH 16
+ u8 reo_wnd_persist:5, /* No. of recovery since last adj */
+ dsack_seen:1, /* Whether DSACK seen after last adj */
+ advanced:1; /* mstamp advanced since last lost marking */
+ } rack;
+ u16 advmss; /* Advertised MSS */
+ u8 compressed_ack;
+ u32 chrono_start; /* Start time in jiffies of a TCP chrono */
+ u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */
+ u8 chrono_type:2, /* current chronograph type */
+ rate_app_limited:1, /* rate_{delivered,interval_us} limited? */
+ fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */
+ fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */
+ is_sack_reneg:1, /* in recovery from loss with SACK reneg? */
+ unused:2;
+ u8 nonagle : 4,/* Disable Nagle algorithm? */
+ thin_lto : 1,/* Use linear timeouts for thin streams */
+ recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */
+ repair : 1,
+ frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */
+ u8 repair_queue;
+ u8 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_fastopen_ch:1, /* Active TFO re-enabling probe */
+ syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
+ save_syn:1, /* Save headers of SYN packet */
+ is_cwnd_limited:1,/* forward progress limited by snd_cwnd? */
+ syn_smc:1; /* SYN includes SMC */
+ u32 tlp_high_seq; /* snd_nxt at the time of TLP retransmit. */
+
+/* RTT measurement */
+ u64 tcp_mstamp; /* most recent packet received/sent */
+ 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 */
+ struct minmax rtt_min;
+
+ 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 reord_seen; /* number of data packet reordering events */
+ 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; /* cwnd right before starting loss recovery */
+ u32 prr_delivered; /* Number of newly delivered packets to
+ * receiver in Recovery. */
+ u32 prr_out; /* Total number of pkts sent during Recovery. */
+ u32 delivered; /* Total data packets delivered incl. rexmits */
+ u32 delivered_ce; /* Like the above but only ECE marked packets */
+ u32 lost; /* Total data packets lost incl. rexmits */
+ u32 app_limited; /* limited until "delivered" reaches this val */
+ u64 first_tx_mstamp; /* start of window send phase */
+ u64 delivered_mstamp; /* time we reached "delivered" */
+ u32 rate_delivered; /* saved rate sample: packets delivered */
+ u32 rate_interval_us; /* saved rate sample: time elapsed */
+
+ 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 */
+
+ struct hrtimer pacing_timer;
+ struct hrtimer compressed_ack_timer;
+
+ /* from STCP, retrans queue hinting */
+ struct sk_buff* lost_skb_hint;
+ struct sk_buff *retransmit_skb_hint;
+
+ /* OOO segments go in this rbtree. Socket lock must be held. */
+ struct rb_root out_of_order_queue;
+ struct sk_buff *ooo_last_skb; /* cache rb_last(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 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. */
+ u64 bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans
+ * Total data bytes retransmitted
+ */
+ 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;
+
+
+/* Sock_ops bpf program related variables */
+#ifdef CONFIG_BPF
+ u8 bpf_sock_ops_cb_flags; /* Control calling BPF programs
+ * values defined in uapi/linux/tcp.h
+ */
+#define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_cb_flags & ARG)
+#else
+#define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0
+#endif
+
+/* Receiver side RTT estimation */
+ u32 rcv_rtt_last_tsecr;
+ struct {
+ u32 rtt_us;
+ u32 seq;
+ u64 time;
+ } rcv_rtt_est;
+
+/* Receiver queue space */
+ struct {
+ u32 space;
+ u32 seq;
+ u64 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
+
+/* 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;
+ u32 *saved_syn;
+};
+
+enum tsq_enum {
+ 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()
+ */
+};
+
+enum tsq_flags {
+ TSQF_THROTTLED = (1UL << TSQ_THROTTLED),
+ TSQF_QUEUED = (1UL << TSQ_QUEUED),
+ TCPF_TSQ_DEFERRED = (1UL << TCP_TSQ_DEFERRED),
+ TCPF_WRITE_TIMER_DEFERRED = (1UL << TCP_WRITE_TIMER_DEFERRED),
+ TCPF_DELACK_TIMER_DEFERRED = (1UL << TCP_DELACK_TIMER_DEFERRED),
+ TCPF_MTU_REDUCED_DEFERRED = (1UL << TCP_MTU_REDUCED_DEFERRED),
+};
+
+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;
+#define tw_rcv_nxt tw_sk.__tw_common.skc_tw_rcv_nxt
+#define tw_snd_nxt tw_sk.__tw_common.skc_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;
+
+ int 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);
+}
+
+static inline void fastopen_queue_tune(struct sock *sk, int backlog)
+{
+ struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
+ int somaxconn = READ_ONCE(sock_net(sk)->core.sysctl_somaxconn);
+
+ queue->fastopenq.max_qlen = min_t(unsigned int, backlog, somaxconn);
+}
+
+static inline void tcp_move_syn(struct tcp_sock *tp,
+ struct request_sock *req)
+{
+ tp->saved_syn = req->saved_syn;
+ req->saved_syn = NULL;
+}
+
+static inline void tcp_saved_syn_free(struct tcp_sock *tp)
+{
+ kfree(tp->saved_syn);
+ tp->saved_syn = NULL;
+}
+
+struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk);
+
+static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss)
+{
+ /* We use READ_ONCE() here because socket might not be locked.
+ * This happens for listeners.
+ */
+ u16 user_mss = READ_ONCE(tp->rx_opt.user_mss);
+
+ return (user_mss && user_mss < mss) ? user_mss : mss;
+}
+#endif /* _LINUX_TCP_H */