475 lines
15 KiB
C
475 lines
15 KiB
C
#ifndef _DCCP_H
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#define _DCCP_H
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/*
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* net/dccp/dccp.h
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*
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* An implementation of the DCCP protocol
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* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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* Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/dccp.h>
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#include <linux/ktime.h>
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#include <net/snmp.h>
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#include <net/sock.h>
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#include <net/tcp.h>
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#include "ackvec.h"
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/*
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* DCCP - specific warning and debugging macros.
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*/
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#define DCCP_WARN(fmt, a...) LIMIT_NETDEBUG(KERN_WARNING "%s: " fmt, \
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__func__, ##a)
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#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \
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__FILE__, __LINE__, __func__)
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#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0)
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#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \
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DCCP_BUG("\"%s\" holds (exception!)", \
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__stringify(cond)); \
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} while (0)
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#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
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printk(fmt, ##args); \
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} while(0)
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#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \
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"%s: " fmt, __func__, ##a)
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#ifdef CONFIG_IP_DCCP_DEBUG
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extern int dccp_debug;
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#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a)
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#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a)
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#define dccp_debug(fmt, a...) dccp_pr_debug_cat(KERN_DEBUG fmt, ##a)
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#else
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#define dccp_pr_debug(format, a...)
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#define dccp_pr_debug_cat(format, a...)
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#define dccp_debug(format, a...)
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#endif
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extern struct inet_hashinfo dccp_hashinfo;
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extern struct percpu_counter dccp_orphan_count;
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extern void dccp_time_wait(struct sock *sk, int state, int timeo);
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/*
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* Set safe upper bounds for header and option length. Since Data Offset is 8
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* bits (RFC 4340, sec. 5.1), the total header length can never be more than
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* 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1):
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* - DCCP-Response with ACK Subheader and 4 bytes of Service code OR
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* - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields
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* Hence a safe upper bound for the maximum option length is 1020-28 = 992
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*/
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#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(uint32_t))
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#define DCCP_MAX_PACKET_HDR 28
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#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR)
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#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER)
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/* Upper bound for initial feature-negotiation overhead (padded to 32 bits) */
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#define DCCP_FEATNEG_OVERHEAD (32 * sizeof(uint32_t))
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#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT
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* state, about 60 seconds */
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/* RFC 1122, 4.2.3.1 initial RTO value */
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#define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ))
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/*
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* The maximum back-off value for retransmissions. This is needed for
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* - retransmitting client-Requests (sec. 8.1.1),
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* - retransmitting Close/CloseReq when closing (sec. 8.3),
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* - feature-negotiation retransmission (sec. 6.6.3),
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* - Acks in client-PARTOPEN state (sec. 8.1.5).
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*/
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#define DCCP_RTO_MAX ((unsigned)(64 * HZ))
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/*
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* RTT sampling: sanity bounds and fallback RTT value from RFC 4340, section 3.4
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*/
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#define DCCP_SANE_RTT_MIN 100
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#define DCCP_FALLBACK_RTT (USEC_PER_SEC / 5)
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#define DCCP_SANE_RTT_MAX (3 * USEC_PER_SEC)
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/* Maximal interval between probes for local resources. */
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#define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U))
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/* sysctl variables for DCCP */
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extern int sysctl_dccp_request_retries;
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extern int sysctl_dccp_retries1;
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extern int sysctl_dccp_retries2;
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extern int sysctl_dccp_tx_qlen;
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extern int sysctl_dccp_sync_ratelimit;
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/*
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* 48-bit sequence number arithmetic (signed and unsigned)
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*/
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#define INT48_MIN 0x800000000000LL /* 2^47 */
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#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */
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#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */
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#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x)))
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#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x)))
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#define ADD48(a, b) (((a) + (b)) & UINT48_MAX)
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#define SUB48(a, b) ADD48((a), COMPLEMENT48(b))
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static inline void dccp_set_seqno(u64 *seqno, u64 value)
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{
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*seqno = value & UINT48_MAX;
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}
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static inline void dccp_inc_seqno(u64 *seqno)
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{
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*seqno = ADD48(*seqno, 1);
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}
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/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
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static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
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{
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u64 delta = SUB48(seqno2, seqno1);
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return TO_SIGNED48(delta);
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}
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/* is seq1 < seq2 ? */
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static inline int before48(const u64 seq1, const u64 seq2)
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{
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return (s64)((seq2 << 16) - (seq1 << 16)) > 0;
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}
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/* is seq1 > seq2 ? */
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#define after48(seq1, seq2) before48(seq2, seq1)
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/* is seq2 <= seq1 <= seq3 ? */
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static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3)
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{
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return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16);
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}
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static inline u64 max48(const u64 seq1, const u64 seq2)
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{
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return after48(seq1, seq2) ? seq1 : seq2;
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}
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/**
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* dccp_loss_free - Evaluates condition for data loss from RFC 4340, 7.7.1
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* @s1: start sequence number
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* @s2: end sequence number
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* @ndp: NDP count on packet with sequence number @s2
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* Returns true if the sequence range s1...s2 has no data loss.
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*/
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static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp)
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{
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s64 delta = dccp_delta_seqno(s1, s2);
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WARN_ON(delta < 0);
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return (u64)delta <= ndp + 1;
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}
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enum {
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DCCP_MIB_NUM = 0,
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DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */
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DCCP_MIB_ESTABRESETS, /* EstabResets */
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DCCP_MIB_CURRESTAB, /* CurrEstab */
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DCCP_MIB_OUTSEGS, /* OutSegs */
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DCCP_MIB_OUTRSTS,
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DCCP_MIB_ABORTONTIMEOUT,
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DCCP_MIB_TIMEOUTS,
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DCCP_MIB_ABORTFAILED,
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DCCP_MIB_PASSIVEOPENS,
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DCCP_MIB_ATTEMPTFAILS,
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DCCP_MIB_OUTDATAGRAMS,
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DCCP_MIB_INERRS,
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DCCP_MIB_OPTMANDATORYERROR,
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DCCP_MIB_INVALIDOPT,
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__DCCP_MIB_MAX
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};
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#define DCCP_MIB_MAX __DCCP_MIB_MAX
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struct dccp_mib {
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unsigned long mibs[DCCP_MIB_MAX];
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} __SNMP_MIB_ALIGN__;
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DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics);
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#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field)
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#define DCCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(dccp_statistics, field)
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#define DCCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(dccp_statistics, field)
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#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field)
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#define DCCP_ADD_STATS_BH(field, val) \
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SNMP_ADD_STATS_BH(dccp_statistics, field, val)
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#define DCCP_ADD_STATS_USER(field, val) \
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SNMP_ADD_STATS_USER(dccp_statistics, field, val)
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/*
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* Checksumming routines
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*/
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static inline unsigned int dccp_csum_coverage(const struct sk_buff *skb)
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{
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const struct dccp_hdr* dh = dccp_hdr(skb);
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if (dh->dccph_cscov == 0)
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return skb->len;
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return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32);
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}
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static inline void dccp_csum_outgoing(struct sk_buff *skb)
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{
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unsigned int cov = dccp_csum_coverage(skb);
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if (cov >= skb->len)
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dccp_hdr(skb)->dccph_cscov = 0;
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skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0);
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}
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extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
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extern int dccp_retransmit_skb(struct sock *sk);
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extern void dccp_send_ack(struct sock *sk);
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extern void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
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struct request_sock *rsk);
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extern void dccp_send_sync(struct sock *sk, const u64 seq,
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const enum dccp_pkt_type pkt_type);
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extern void dccp_write_xmit(struct sock *sk, int block);
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extern void dccp_write_space(struct sock *sk);
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extern void dccp_init_xmit_timers(struct sock *sk);
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static inline void dccp_clear_xmit_timers(struct sock *sk)
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{
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inet_csk_clear_xmit_timers(sk);
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}
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extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu);
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extern const char *dccp_packet_name(const int type);
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extern const char *dccp_state_name(const int state);
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extern void dccp_set_state(struct sock *sk, const int state);
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extern void dccp_done(struct sock *sk);
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extern int dccp_reqsk_init(struct request_sock *rq, struct dccp_sock const *dp,
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struct sk_buff const *skb);
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extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
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extern struct sock *dccp_create_openreq_child(struct sock *sk,
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const struct request_sock *req,
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const struct sk_buff *skb);
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extern int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
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extern struct sock *dccp_v4_request_recv_sock(struct sock *sk,
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struct sk_buff *skb,
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struct request_sock *req,
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struct dst_entry *dst);
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extern struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
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struct request_sock *req,
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struct request_sock **prev);
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extern int dccp_child_process(struct sock *parent, struct sock *child,
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struct sk_buff *skb);
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extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
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struct dccp_hdr *dh, unsigned len);
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extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
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const struct dccp_hdr *dh, const unsigned len);
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extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
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extern void dccp_destroy_sock(struct sock *sk);
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extern void dccp_close(struct sock *sk, long timeout);
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extern struct sk_buff *dccp_make_response(struct sock *sk,
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struct dst_entry *dst,
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struct request_sock *req);
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extern int dccp_connect(struct sock *sk);
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extern int dccp_disconnect(struct sock *sk, int flags);
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extern int dccp_getsockopt(struct sock *sk, int level, int optname,
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char __user *optval, int __user *optlen);
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extern int dccp_setsockopt(struct sock *sk, int level, int optname,
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char __user *optval, unsigned int optlen);
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#ifdef CONFIG_COMPAT
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extern int compat_dccp_getsockopt(struct sock *sk,
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int level, int optname,
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char __user *optval, int __user *optlen);
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extern int compat_dccp_setsockopt(struct sock *sk,
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int level, int optname,
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char __user *optval, unsigned int optlen);
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#endif
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extern int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg);
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extern int dccp_sendmsg(struct kiocb *iocb, struct sock *sk,
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struct msghdr *msg, size_t size);
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extern int dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
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struct msghdr *msg, size_t len, int nonblock,
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int flags, int *addr_len);
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extern void dccp_shutdown(struct sock *sk, int how);
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extern int inet_dccp_listen(struct socket *sock, int backlog);
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extern unsigned int dccp_poll(struct file *file, struct socket *sock,
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poll_table *wait);
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extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
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int addr_len);
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extern struct sk_buff *dccp_ctl_make_reset(struct sock *sk,
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struct sk_buff *skb);
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extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code);
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extern void dccp_send_close(struct sock *sk, const int active);
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extern int dccp_invalid_packet(struct sk_buff *skb);
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extern u32 dccp_sample_rtt(struct sock *sk, long delta);
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static inline int dccp_bad_service_code(const struct sock *sk,
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const __be32 service)
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{
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const struct dccp_sock *dp = dccp_sk(sk);
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if (dp->dccps_service == service)
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return 0;
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return !dccp_list_has_service(dp->dccps_service_list, service);
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}
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/**
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* dccp_skb_cb - DCCP per-packet control information
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* @dccpd_type: one of %dccp_pkt_type (or unknown)
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* @dccpd_ccval: CCVal field (5.1), see e.g. RFC 4342, 8.1
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* @dccpd_reset_code: one of %dccp_reset_codes
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* @dccpd_reset_data: Data1..3 fields (depend on @dccpd_reset_code)
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* @dccpd_opt_len: total length of all options (5.8) in the packet
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* @dccpd_seq: sequence number
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* @dccpd_ack_seq: acknowledgment number subheader field value
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* This is used for transmission as well as for reception.
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*/
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struct dccp_skb_cb {
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union {
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struct inet_skb_parm h4;
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#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
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struct inet6_skb_parm h6;
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#endif
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} header;
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__u8 dccpd_type:4;
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__u8 dccpd_ccval:4;
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__u8 dccpd_reset_code,
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dccpd_reset_data[3];
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__u16 dccpd_opt_len;
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__u64 dccpd_seq;
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__u64 dccpd_ack_seq;
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};
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#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0]))
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/* RFC 4340, sec. 7.7 */
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static inline int dccp_non_data_packet(const struct sk_buff *skb)
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{
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const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
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return type == DCCP_PKT_ACK ||
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type == DCCP_PKT_CLOSE ||
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type == DCCP_PKT_CLOSEREQ ||
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type == DCCP_PKT_RESET ||
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type == DCCP_PKT_SYNC ||
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type == DCCP_PKT_SYNCACK;
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}
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/* RFC 4340, sec. 7.7 */
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static inline int dccp_data_packet(const struct sk_buff *skb)
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{
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const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
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return type == DCCP_PKT_DATA ||
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type == DCCP_PKT_DATAACK ||
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type == DCCP_PKT_REQUEST ||
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type == DCCP_PKT_RESPONSE;
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}
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static inline int dccp_packet_without_ack(const struct sk_buff *skb)
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{
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const __u8 type = DCCP_SKB_CB(skb)->dccpd_type;
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return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST;
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}
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#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2)
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static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss)
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{
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struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh +
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sizeof(*dh));
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dh->dccph_seq2 = 0;
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dh->dccph_seq = htons((gss >> 32) & 0xfffff);
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dhx->dccph_seq_low = htonl(gss & 0xffffffff);
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}
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static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack,
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const u64 gsr)
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{
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dhack->dccph_reserved1 = 0;
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dhack->dccph_ack_nr_high = htons(gsr >> 32);
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dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff);
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}
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static inline void dccp_update_gsr(struct sock *sk, u64 seq)
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{
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struct dccp_sock *dp = dccp_sk(sk);
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dp->dccps_gsr = seq;
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/* Sequence validity window depends on remote Sequence Window (7.5.1) */
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dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4);
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dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4);
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}
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static inline void dccp_update_gss(struct sock *sk, u64 seq)
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|
{
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struct dccp_sock *dp = dccp_sk(sk);
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|
|
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dp->dccps_gss = seq;
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/* Ack validity window depends on local Sequence Window value (7.5.1) */
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dp->dccps_awl = SUB48(ADD48(dp->dccps_gss, 1), dp->dccps_l_seq_win);
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dp->dccps_awh = dp->dccps_gss;
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}
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|
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static inline int dccp_ack_pending(const struct sock *sk)
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|
{
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|
const struct dccp_sock *dp = dccp_sk(sk);
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|
return dp->dccps_timestamp_echo != 0 ||
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|
(dp->dccps_hc_rx_ackvec != NULL &&
|
|
dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||
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inet_csk_ack_scheduled(sk);
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}
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|
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extern int dccp_feat_finalise_settings(struct dccp_sock *dp);
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|
extern int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq);
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|
extern int dccp_feat_insert_opts(struct dccp_sock*, struct dccp_request_sock*,
|
|
struct sk_buff *skb);
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|
extern int dccp_feat_activate_values(struct sock *sk, struct list_head *fn);
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|
extern void dccp_feat_list_purge(struct list_head *fn_list);
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|
|
|
extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
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|
extern int dccp_insert_options_rsk(struct dccp_request_sock*, struct sk_buff*);
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|
extern int dccp_insert_option_elapsed_time(struct sock *sk,
|
|
struct sk_buff *skb,
|
|
u32 elapsed_time);
|
|
extern u32 dccp_timestamp(void);
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|
extern void dccp_timestamping_init(void);
|
|
extern int dccp_insert_option_timestamp(struct sock *sk,
|
|
struct sk_buff *skb);
|
|
extern int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
|
|
unsigned char option,
|
|
const void *value, unsigned char len);
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
extern int dccp_sysctl_init(void);
|
|
extern void dccp_sysctl_exit(void);
|
|
#else
|
|
static inline int dccp_sysctl_init(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void dccp_sysctl_exit(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#endif /* _DCCP_H */
|