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109 lines
3.4 KiB
C
109 lines
3.4 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Definitions for the TCP protocol.
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*
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* Version: @(#)tcp.h 1.0.2 04/28/93
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*
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* Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _LINUX_TCP_H
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#define _LINUX_TCP_H
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#include <linux/skbuff.h>
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#include <uapi/linux/tcp.h>
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static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb)
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{
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return (struct tcphdr *)skb_transport_header(skb);
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}
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static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)
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{
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return tcp_hdr(skb)->doff * 4;
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}
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static inline unsigned int tcp_optlen(const struct sk_buff *skb)
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{
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return (tcp_hdr(skb)->doff - 5) * 4;
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}
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/* TCP Fast Open */
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#define TCP_FASTOPEN_COOKIE_MIN 4 /* Min Fast Open Cookie size in bytes */
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#define TCP_FASTOPEN_COOKIE_MAX 16 /* Max Fast Open Cookie size in bytes */
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#define TCP_FASTOPEN_COOKIE_SIZE 8 /* the size employed by this impl. */
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/* TCP Fast Open Cookie as stored in memory */
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struct tcp_fastopen_cookie {
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s8 len;
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u8 val[TCP_FASTOPEN_COOKIE_MAX];
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};
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/* This defines a selective acknowledgement block. */
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struct tcp_sack_block_wire {
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__be32 start_seq;
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__be32 end_seq;
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};
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struct tcp_sack_block {
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u32 start_seq;
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u32 end_seq;
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};
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/*These are used to set the sack_ok field in struct tcp_options_received */
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#define TCP_SACK_SEEN (1 << 0) /*1 = peer is SACK capable, */
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#define TCP_FACK_ENABLED (1 << 1) /*1 = FACK is enabled locally*/
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#define TCP_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/
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struct tcp_options_received {
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/* PAWS/RTTM data */
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long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
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u32 ts_recent; /* Time stamp to echo next */
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u32 rcv_tsval; /* Time stamp value */
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u32 rcv_tsecr; /* Time stamp echo reply */
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u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
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tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
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dsack : 1, /* D-SACK is scheduled */
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wscale_ok : 1, /* Wscale seen on SYN packet */
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sack_ok : 4, /* SACK seen on SYN packet */
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snd_wscale : 4, /* Window scaling received from sender */
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rcv_wscale : 4; /* Window scaling to send to receiver */
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u8 num_sacks; /* Number of SACK blocks */
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u16 user_mss; /* mss requested by user in ioctl */
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u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
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};
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static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
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{
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rx_opt->tstamp_ok = rx_opt->sack_ok = 0;
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rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
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}
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/* This is the max number of SACKS that we'll generate and process. It's safe
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* to increase this, although since:
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* size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8)
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* only four options will fit in a standard TCP header */
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#define TCP_NUM_SACKS 4
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enum tsq_flags {
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TSQ_THROTTLED,
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TSQ_QUEUED,
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TCP_TSQ_DEFERRED, /* tcp_tasklet_func() found socket was owned */
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TCP_WRITE_TIMER_DEFERRED, /* tcp_write_timer() found socket was owned */
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TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */
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TCP_MTU_REDUCED_DEFERRED, /* tcp_v{4|6}_err() could not call
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* tcp_v{4|6}_mtu_reduced()
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*/
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};
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#endif /* _LINUX_TCP_H */
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