xref: /freebsd/sys/netinet/tcp_syncache.h (revision 15c433351f54e7cd5bec8d36c8e89e6a7fa55b26)
1 /*-
2  * Copyright (c) 1982, 1986, 1993, 1994, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)tcp_var.h	8.4 (Berkeley) 5/24/95
30  * $FreeBSD$
31  */
32 
33 #ifndef _NETINET_TCP_SYNCACHE_H_
34 #define _NETINET_TCP_SYNCACHE_H_
35 #ifdef _KERNEL
36 
37 void	 syncache_init(void);
38 #ifdef VIMAGE
39 void	syncache_destroy(void);
40 #endif
41 void	 syncache_unreach(struct in_conninfo *, struct tcphdr *);
42 int	 syncache_expand(struct in_conninfo *, struct tcpopt *,
43 	     struct tcphdr *, struct socket **, struct mbuf *);
44 int	 syncache_add(struct in_conninfo *, struct tcpopt *,
45 	     struct tcphdr *, struct inpcb *, struct socket **, struct mbuf *,
46 	     void *, void *);
47 void	 syncache_chkrst(struct in_conninfo *, struct tcphdr *);
48 void	 syncache_badack(struct in_conninfo *);
49 int	 syncache_pcblist(struct sysctl_req *req, int max_pcbs, int *pcbs_exported);
50 
51 struct syncache {
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_int32_t	sc_tsreflect;		/* timestamp to reflect */
57 	u_int32_t	sc_ts;			/* our timestamp to send */
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;		/* IPv4 TTL */
66 	u_int8_t	sc_ip_tos;		/* IPv4 TOS */
67 	u_int8_t	sc_requested_s_scale:4,
68 			sc_requested_r_scale:4;
69 	u_int16_t	sc_flags;
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 */
73 #endif
74 	struct label	*sc_label;		/* MAC label reference */
75 	struct ucred	*sc_cred;		/* cred cache for jail checks */
76 #ifdef TCP_RFC7413
77 	void		*sc_tfo_cookie;		/* for TCP Fast Open response */
78 #endif
79 	void		*sc_pspare;		/* TCP_SIGNATURE */
80 	u_int32_t	sc_spare[2];		/* UTO */
81 };
82 
83 /*
84  * Flags for the sc_flags field.
85  */
86 #define SCF_NOOPT	0x01			/* no TCP options */
87 #define SCF_WINSCALE	0x02			/* negotiated window scaling */
88 #define SCF_TIMESTAMP	0x04			/* negotiated timestamps */
89 						/* MSS is implicit */
90 #define SCF_UNREACH	0x10			/* icmp unreachable received */
91 #define SCF_SIGNATURE	0x20			/* send MD5 digests */
92 #define SCF_SACK	0x80			/* send SACK option */
93 #define SCF_ECN		0x100			/* send ECN setup packet */
94 
95 struct syncache_head {
96 	struct mtx	sch_mtx;
97 	TAILQ_HEAD(sch_head, syncache)	sch_bucket;
98 	struct callout	sch_timer;
99 	int		sch_nextc;
100 	u_int		sch_length;
101 	struct tcp_syncache *sch_sc;
102 };
103 
104 #define	SYNCOOKIE_SECRET_SIZE	16
105 #define	SYNCOOKIE_LIFETIME	15		/* seconds */
106 
107 struct syncookie_secret {
108 	volatile u_int oddeven;
109 	uint8_t key[2][SYNCOOKIE_SECRET_SIZE];
110 	struct callout reseed;
111 	u_int lifetime;
112 };
113 
114 struct tcp_syncache {
115 	struct	syncache_head *hashbase;
116 	uma_zone_t zone;
117 	u_int	hashsize;
118 	u_int	hashmask;
119 	u_int	bucket_limit;
120 	u_int	cache_limit;
121 	u_int	rexmt_limit;
122 	uint32_t hash_secret;
123 	struct vnet *vnet;
124 	struct syncookie_secret secret;
125 };
126 
127 /* Internal use for the syncookie functions. */
128 union syncookie {
129 	uint8_t cookie;
130 	struct {
131 		uint8_t odd_even:1,
132 			sack_ok:1,
133 			wscale_idx:3,
134 			mss_idx:3;
135 	} flags;
136 };
137 
138 #endif /* _KERNEL */
139 #endif /* !_NETINET_TCP_SYNCACHE_H_ */
140