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31 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
35 #ifndef _NETINET_TCP_SYNCACHE_H_
36 #define _NETINET_TCP_SYNCACHE_H_
39 void syncache_init(void);
41 void syncache_destroy(void);
43 void syncache_unreach(struct in_conninfo *, tcp_seq);
44 int syncache_expand(struct in_conninfo *, struct tcpopt *,
45 struct tcphdr *, struct socket **, struct mbuf *);
46 int syncache_add(struct in_conninfo *, struct tcpopt *,
47 struct tcphdr *, struct inpcb *, struct socket **, struct mbuf *,
49 void syncache_chkrst(struct in_conninfo *, struct tcphdr *);
50 void syncache_badack(struct in_conninfo *);
51 int syncache_pcblist(struct sysctl_req *req, int max_pcbs, int *pcbs_exported);
54 TAILQ_ENTRY(syncache) sc_hash;
55 struct in_conninfo sc_inc; /* addresses */
56 int sc_rxttime; /* retransmit time */
57 u_int16_t sc_rxmits; /* retransmit counter */
58 u_int32_t sc_tsreflect; /* timestamp to reflect */
59 u_int32_t sc_ts; /* our timestamp to send */
60 u_int32_t sc_tsoff; /* ts offset w/ syncookies */
61 u_int32_t sc_flowlabel; /* IPv6 flowlabel */
62 tcp_seq sc_irs; /* seq from peer */
63 tcp_seq sc_iss; /* our ISS */
64 struct mbuf *sc_ipopts; /* source route */
65 u_int16_t sc_peer_mss; /* peer's MSS */
66 u_int16_t sc_wnd; /* advertised window */
67 u_int8_t sc_ip_ttl; /* IPv4 TTL */
68 u_int8_t sc_ip_tos; /* IPv4 TOS */
69 u_int8_t sc_requested_s_scale:4,
70 sc_requested_r_scale:4;
72 #if defined(TCP_OFFLOAD) || !defined(TCP_OFFLOAD_DISABLE)
73 struct toedev *sc_tod; /* entry added by this TOE */
74 void *sc_todctx; /* TOE driver context */
76 struct label *sc_label; /* MAC label reference */
77 struct ucred *sc_cred; /* cred cache for jail checks */
79 void *sc_tfo_cookie; /* for TCP Fast Open response */
81 void *sc_pspare; /* TCP_SIGNATURE */
82 u_int32_t sc_spare[2]; /* UTO */
86 * Flags for the sc_flags field.
88 #define SCF_NOOPT 0x01 /* no TCP options */
89 #define SCF_WINSCALE 0x02 /* negotiated window scaling */
90 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
92 #define SCF_UNREACH 0x10 /* icmp unreachable received */
93 #define SCF_SIGNATURE 0x20 /* send MD5 digests */
94 #define SCF_SACK 0x80 /* send SACK option */
95 #define SCF_ECN 0x100 /* send ECN setup packet */
97 struct syncache_head {
99 TAILQ_HEAD(sch_head, syncache) sch_bucket;
100 struct callout sch_timer;
103 struct tcp_syncache *sch_sc;
104 time_t sch_last_overflow;
107 #define SYNCOOKIE_SECRET_SIZE 16
108 #define SYNCOOKIE_LIFETIME 15 /* seconds */
110 struct syncookie_secret {
111 volatile u_int oddeven;
112 uint8_t key[2][SYNCOOKIE_SECRET_SIZE];
113 struct callout reseed;
117 struct tcp_syncache {
118 struct syncache_head *hashbase;
125 uint32_t hash_secret;
127 struct syncookie_secret secret;
130 /* Internal use for the syncookie functions. */
142 #endif /* !_NETINET_TCP_SYNCACHE_H_ */