diff options
Diffstat (limited to 'kernel/include/linux/tcp.h')
| -rw-r--r-- | kernel/include/linux/tcp.h | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/kernel/include/linux/tcp.h b/kernel/include/linux/tcp.h new file mode 100644 index 000000000..e8bbf4036 --- /dev/null +++ b/kernel/include/linux/tcp.h @@ -0,0 +1,398 @@ +/* + * 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 <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 + +/* 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 */ |