43b223f42e
enabled use an updated timestamp instead of reusing the one used in the initial TCP SYN-ACK segment. This patch ensures that an updated timestamp is used when sending the SYN-ACK from the syncache code. It was already done if the SYN-ACK was retransmitted from the generic code. This makes the behaviour consistent and also conformant with the TCP specification. Reviewed by: jtl@, Jason Eggleston MFC after: 1 month Sponsored by: Neflix, Inc. Differential Revision: https://reviews.freebsd.org/D15634
140 lines
4.7 KiB
C
140 lines
4.7 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1982, 1986, 1993, 1994, 1995
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
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* $FreeBSD$
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*/
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#ifndef _NETINET_TCP_SYNCACHE_H_
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#define _NETINET_TCP_SYNCACHE_H_
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#ifdef _KERNEL
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void syncache_init(void);
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#ifdef VIMAGE
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void syncache_destroy(void);
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#endif
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void syncache_unreach(struct in_conninfo *, tcp_seq);
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int syncache_expand(struct in_conninfo *, struct tcpopt *,
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struct tcphdr *, struct socket **, struct mbuf *);
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int syncache_add(struct in_conninfo *, struct tcpopt *,
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struct tcphdr *, struct inpcb *, struct socket **, struct mbuf *,
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void *, void *);
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void syncache_chkrst(struct in_conninfo *, struct tcphdr *);
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void syncache_badack(struct in_conninfo *);
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int syncache_pcblist(struct sysctl_req *req, int max_pcbs, int *pcbs_exported);
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struct syncache {
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TAILQ_ENTRY(syncache) sc_hash;
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struct in_conninfo sc_inc; /* addresses */
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int sc_rxttime; /* retransmit time */
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u_int16_t sc_rxmits; /* retransmit counter */
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u_int32_t sc_tsreflect; /* timestamp to reflect */
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u_int32_t sc_tsoff; /* ts offset w/ syncookies */
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u_int32_t sc_flowlabel; /* IPv6 flowlabel */
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tcp_seq sc_irs; /* seq from peer */
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tcp_seq sc_iss; /* our ISS */
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struct mbuf *sc_ipopts; /* source route */
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u_int16_t sc_peer_mss; /* peer's MSS */
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u_int16_t sc_wnd; /* advertised window */
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u_int8_t sc_ip_ttl; /* IPv4 TTL */
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u_int8_t sc_ip_tos; /* IPv4 TOS */
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u_int8_t sc_requested_s_scale:4,
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sc_requested_r_scale:4;
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u_int16_t sc_flags;
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#if defined(TCP_OFFLOAD) || !defined(TCP_OFFLOAD_DISABLE)
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struct toedev *sc_tod; /* entry added by this TOE */
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void *sc_todctx; /* TOE driver context */
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#endif
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struct label *sc_label; /* MAC label reference */
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struct ucred *sc_cred; /* cred cache for jail checks */
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void *sc_tfo_cookie; /* for TCP Fast Open response */
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void *sc_pspare; /* TCP_SIGNATURE */
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u_int32_t sc_spare[2]; /* UTO */
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};
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/*
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* Flags for the sc_flags field.
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*/
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#define SCF_NOOPT 0x01 /* no TCP options */
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#define SCF_WINSCALE 0x02 /* negotiated window scaling */
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#define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
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/* MSS is implicit */
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#define SCF_UNREACH 0x10 /* icmp unreachable received */
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#define SCF_SIGNATURE 0x20 /* send MD5 digests */
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#define SCF_SACK 0x80 /* send SACK option */
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#define SCF_ECN 0x100 /* send ECN setup packet */
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struct syncache_head {
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struct mtx sch_mtx;
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TAILQ_HEAD(sch_head, syncache) sch_bucket;
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struct callout sch_timer;
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int sch_nextc;
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u_int sch_length;
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struct tcp_syncache *sch_sc;
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time_t sch_last_overflow;
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};
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#define SYNCOOKIE_SECRET_SIZE 16
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#define SYNCOOKIE_LIFETIME 15 /* seconds */
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struct syncookie_secret {
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volatile u_int oddeven;
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uint8_t key[2][SYNCOOKIE_SECRET_SIZE];
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struct callout reseed;
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u_int lifetime;
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};
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struct tcp_syncache {
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struct syncache_head *hashbase;
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uma_zone_t zone;
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u_int hashsize;
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u_int hashmask;
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u_int bucket_limit;
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u_int cache_limit;
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u_int rexmt_limit;
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uint32_t hash_secret;
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struct vnet *vnet;
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struct syncookie_secret secret;
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};
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/* Internal use for the syncookie functions. */
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union syncookie {
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uint8_t cookie;
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struct {
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uint8_t odd_even:1,
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sack_ok:1,
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wscale_idx:3,
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mss_idx:3;
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} flags;
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};
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#endif /* _KERNEL */
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#endif /* !_NETINET_TCP_SYNCACHE_H_ */
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