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32 #ifndef _NETINET_TCP_SYNCACHE_H_
33 #define _NETINET_TCP_SYNCACHE_H_
36 void syncache_init(void);
38 void syncache_destroy(void);
40 void syncache_unreach(struct in_conninfo *, tcp_seq, uint16_t);
41 int syncache_expand(struct in_conninfo *, struct tcpopt *,
42 struct tcphdr *, struct socket **, struct mbuf *, uint16_t);
43 struct socket * syncache_add(struct in_conninfo *, struct tcpopt *,
44 struct tcphdr *, struct inpcb *, struct socket *, struct mbuf *,
45 void *, void *, uint8_t, uint16_t);
46 void syncache_chkrst(struct in_conninfo *, struct tcphdr *, struct mbuf *,
48 void syncache_badack(struct in_conninfo *, uint16_t);
49 int syncache_pcblist(struct sysctl_req *);
52 TAILQ_ENTRY(syncache) sc_hash;
53 struct in_conninfo sc_inc; /* addresses */
54 int sc_rxttime; /* retransmit time */
55 u_int16_t sc_rxmits; /* retransmit counter */
56 u_int16_t sc_port; /* remote UDP encaps port */
57 u_int32_t sc_tsreflect; /* timestamp to reflect */
58 u_int32_t sc_tsoff; /* ts offset w/ syncookies */
59 u_int32_t sc_flowlabel; /* IPv6 flowlabel */
60 tcp_seq sc_irs; /* seq from peer */
61 tcp_seq sc_iss; /* our ISS */
62 struct mbuf *sc_ipopts; /* source route */
63 u_int16_t sc_peer_mss; /* peer's MSS */
64 u_int16_t sc_wnd; /* advertised window */
65 u_int8_t sc_ip_ttl; /* TTL / Hop Limit */
66 u_int8_t sc_ip_tos; /* TOS / Traffic Class */
67 u_int8_t sc_requested_s_scale:4,
68 sc_requested_r_scale:4;
70 #if defined(TCP_OFFLOAD) || !defined(TCP_OFFLOAD_DISABLE)
71 struct toedev *sc_tod; /* entry added by this TOE */
72 void *sc_todctx; /* TOE driver context */
74 struct label *sc_label; /* MAC label reference */
75 struct ucred *sc_cred; /* cred cache for jail checks */
76 void *sc_tfo_cookie; /* for TCP Fast Open response */
77 void *sc_pspare; /* TCP_SIGNATURE */
78 u_int32_t sc_spare[2]; /* UTO */
82 * Flags for the sc_flags field.
84 #define SCF_NOOPT 0x01 /* no TCP options */
85 #define SCF_WINSCALE 0x02 /* negotiated window scaling */
86 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
88 #define SCF_UNREACH 0x10 /* icmp unreachable received */
89 #define SCF_SIGNATURE 0x20 /* send MD5 digests */
90 #define SCF_SACK 0x80 /* send SACK option */
91 #define SCF_ECN_MASK 0x700 /* ECN codepoint mask */
92 #define SCF_ECN 0x100 /* send ECN setup packet */
93 #define SCF_ACE_N 0x400 /* send ACE non-ECT setup */
94 #define SCF_ACE_0 0x500 /* send ACE ECT0 setup */
95 #define SCF_ACE_1 0x600 /* send ACE ECT1 setup */
96 #define SCF_ACE_CE 0x700 /* send ACE CE setup */
98 struct syncache_head {
100 TAILQ_HEAD(sch_head, syncache) sch_bucket;
101 struct callout sch_timer;
104 struct tcp_syncache *sch_sc;
105 time_t sch_last_overflow;
108 #define SYNCOOKIE_SECRET_SIZE 16
109 #define SYNCOOKIE_LIFETIME 15 /* seconds */
111 struct syncookie_secret {
112 volatile u_int oddeven;
113 uint8_t key[2][SYNCOOKIE_SECRET_SIZE];
114 struct callout reseed;
118 #define TCP_SYNCACHE_PAUSE_TIME SYNCOOKIE_LIFETIME
119 #define TCP_SYNCACHE_MAX_BACKOFF 6 /* 16 minutes */
121 struct tcp_syncache {
122 struct syncache_head *hashbase;
129 uint32_t hash_secret;
131 struct syncookie_secret secret;
132 struct mtx pause_mtx;
133 struct callout pause_co;
135 uint8_t pause_backoff;
136 volatile bool paused;
140 /* Internal use for the syncookie functions. */
152 #endif /* !_NETINET_TCP_SYNCACHE_H_ */