xref: /xnu-12377.41.6/bsd/netinet/tcp.h (revision bbb1b6f9e71b8cdde6e5cd6f4841f207dee3d828)
1 /*
2  * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*
29  * Copyright (c) 1982, 1986, 1993
30  *	The Regents of the University of California.  All rights reserved.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  * 3. All advertising materials mentioning features or use of this software
41  *    must display the following acknowledgement:
42  *	This product includes software developed by the University of
43  *	California, Berkeley and its contributors.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)tcp.h	8.1 (Berkeley) 6/10/93
61  * $FreeBSD: src/sys/netinet/tcp.h,v 1.13.2.3 2001/03/01 22:08:42 jlemon Exp $
62  */
63 
64 #ifndef _NETINET_TCP_H_
65 #define _NETINET_TCP_H_
66 #ifndef DRIVERKIT
67 #include <sys/appleapiopts.h>
68 #include <sys/socket.h>
69 #include <sys/types.h>
70 #endif /* DRIVERKIT */
71 
72 #include <machine/endian.h>
73 #include <machine/types.h> /* __uint32_t */
74 #include <netinet/in.h>
75 
76 #ifndef DRIVERKIT
77 #include <sys/types.h>
78 #else
79 #include <sys/_types.h>
80 #endif /* DRIVERKIT */
81 
82 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
83 typedef __uint32_t tcp_seq;
84 typedef __uint32_t tcp_cc;              /* connection count per rfc1644 */
85 
86 #define tcp6_seq        tcp_seq /* for KAME src sync over BSD*'s */
87 #define tcp6hdr         tcphdr  /* for KAME src sync over BSD*'s */
88 
89 /*
90  * TCP header.
91  * Per RFC 793, September, 1981.
92  */
93 struct tcphdr {
94 	unsigned short  th_sport;       /* source port */
95 	unsigned short  th_dport;       /* destination port */
96 	tcp_seq th_seq;                 /* sequence number */
97 	tcp_seq th_ack;                 /* acknowledgement number */
98 #if __DARWIN_BYTE_ORDER == __DARWIN_LITTLE_ENDIAN
99 	unsigned int    th_x2:4,        /* (unused) */
100 	    th_off:4;                   /* data offset */
101 #endif
102 #if __DARWIN_BYTE_ORDER == __DARWIN_BIG_ENDIAN
103 	unsigned int    th_off:4,       /* data offset */
104 	    th_x2:4;                    /* (unused) */
105 #endif
106 	unsigned char   th_flags;
107 #define TH_FIN  0x01
108 #define TH_SYN  0x02
109 #define TH_RST  0x04
110 #define TH_PUSH 0x08
111 #define TH_ACK  0x10
112 #define TH_URG  0x20
113 #define TH_ECE  0x40
114 #define TH_CWR  0x80
115 #define TH_AE   0x100                   /* maps into th_x2 */
116 #define TH_FLAGS        (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)
117 #define TH_FLAGS_ALL    (TH_FLAGS|TH_PUSH)
118 #define TH_ACCEPT       (TH_FIN|TH_SYN|TH_RST|TH_ACK)
119 #define TH_ACE          (TH_AE|TH_CWR|TH_ECE)
120 
121 	unsigned short  th_win;         /* window */
122 	unsigned short  th_sum;         /* checksum */
123 	unsigned short  th_urp;         /* urgent pointer */
124 };
125 
126 #define TCPOPT_EOL              0
127 #define TCPOLEN_EOL             1
128 #define TCPOPT_NOP              1
129 #define TCPOLEN_NOP             1
130 #define TCPOPT_MAXSEG           2
131 #define TCPOLEN_MAXSEG          4
132 #define TCPOPT_WINDOW           3
133 #define TCPOLEN_WINDOW          3
134 #define TCPOPT_SACK_PERMITTED   4               /* SACK capability in SYN */
135 #define TCPOLEN_SACK_PERMITTED  2
136 #define TCPOPT_SACK             5
137 #define TCPOLEN_SACKHDR         2
138 #define TCPOLEN_SACK            8               /* len of sack block */
139 #define TCPOPT_TIMESTAMP        8
140 #define TCPOLEN_TIMESTAMP       10
141 #define TCPOLEN_TSTAMP_APPA             (TCPOLEN_TIMESTAMP+2) /* appendix A */
142 #define TCPOPT_TSTAMP_HDR               \
143     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
144 
145 #define MAX_TCPOPTLEN           40      /* Absolute maximum TCP options len */
146 
147 #define TCPOPT_CC               11              /* CC options: RFC-1644 */
148 #define TCPOPT_CCNEW            12
149 #define TCPOPT_CCECHO           13
150 #define    TCPOLEN_CC                   6
151 #define    TCPOLEN_CC_APPA              (TCPOLEN_CC+2)
152 #define    TCPOPT_CC_HDR(ccopt)         \
153     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|(ccopt)<<8|TCPOLEN_CC)
154 #define TCPOPT_SIGNATURE                19      /* Keyed MD5: RFC 2385 */
155 #define    TCPOLEN_SIGNATURE            18
156 #if MPTCP
157 #define TCPOPT_MULTIPATH                30
158 #endif
159 
160 #define TCPOPT_FASTOPEN                 34
161 #define TCPOLEN_FASTOPEN_REQ            2
162 
163 #define TCPOPT_ACCECN0                  172 /* AccECN Order 0 */
164 #define TCPOPT_ACCECN1                  174 /* AccECN Order 1 */
165 #define TCPOLEN_ACCECN_EMPTY            2    /* Empty option contains kind and length */
166 #define TCPOLEN_ACCECN_COUNTER          3    /* Length of each AccECN counter */
167 
168 /* Option definitions */
169 #define TCPOPT_SACK_PERMIT_HDR  \
170 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED)
171 #define TCPOPT_SACK_HDR         (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8)
172 /* Miscellaneous constants */
173 #define MAX_SACK_BLKS   6       /* Max # SACK blocks stored at sender side */
174 
175 /*
176  * A SACK option that specifies n blocks will have a length of (8*n + 2)
177  * bytes, so the 40 bytes available for TCP options can specify a
178  * maximum of 4 blocks.
179  */
180 
181 #define TCP_MAX_SACK    4       /* MAX # SACKs sent in any segment */
182 
183 
184 /*
185  * Default maximum segment size for TCP.
186  * With an IP MTU of 576, this is 536,
187  * but 512 is probably more convenient.
188  * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
189  */
190 #define TCP_MSS 512
191 
192 /*
193  * TCP_MINMSS is defined to be 216 which is fine for the smallest
194  * link MTU (256 bytes, SLIP interface) in the Internet.
195  * However it is very unlikely to come across such low MTU interfaces
196  * these days (anno dato 2004).
197  * Probably it can be set to 512 without ill effects. But we play safe.
198  * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments.
199  * Setting this to "0" disables the minmss check.
200  */
201 #define TCP_MINMSS 216
202 
203 /*
204  * Default maximum segment size for TCP6.
205  * With an IP6 MSS of 1280, this is 1220,
206  * but 1024 is probably more convenient. (xxx kazu in doubt)
207  * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr))
208  */
209 #define TCP6_MSS        1024
210 
211 #define TCP_MAXWIN      65535   /* largest value for (unscaled) window */
212 #define TTCP_CLIENT_SND_WND     4096    /* dflt send window for T/TCP client */
213 
214 #define TCP_MAX_WINSHIFT        14      /* maximum window shift */
215 
216 #define TCP_MAXHLEN     (0xf<<2)        /* max length of header in bytes */
217 #define TCP_MAXOLEN     (TCP_MAXHLEN - sizeof(struct tcphdr))
218 /* max space left for options */
219 #endif /* (_POSIX_C_SOURCE && !_DARWIN_C_SOURCE) */
220 
221 /*
222  * User-settable options (used with setsockopt).
223  */
224 #define TCP_NODELAY             0x01    /* don't delay send to coalesce packets */
225 #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
226 #define TCP_MAXSEG              0x02    /* set maximum segment size */
227 #define TCP_NOPUSH              0x04    /* don't push last block of write */
228 #define TCP_NOOPT               0x08    /* don't use TCP options */
229 #define TCP_KEEPALIVE           0x10    /* idle time used when SO_KEEPALIVE is enabled */
230 #define TCP_CONNECTIONTIMEOUT   0x20    /* connection timeout */
231 #define PERSIST_TIMEOUT         0x40    /* time after which a connection in
232 	                                 *  persist timeout will terminate.
233 	                                 *  see draft-ananth-tcpm-persist-02.txt
234 	                                 */
235 #define TCP_RXT_CONNDROPTIME    0x80    /* time after which tcp retransmissions will be
236 	                                 * stopped and the connection will be dropped
237 	                                 */
238 #define TCP_RXT_FINDROP         0x100   /* when this option is set, drop a connection
239 	                                 * after retransmitting the FIN 3 times. It will
240 	                                 * prevent holding too many mbufs in socket
241 	                                 * buffer queues.
242 	                                 */
243 #define TCP_KEEPINTVL           0x101   /* interval between keepalives */
244 #define TCP_KEEPCNT             0x102   /* number of keepalives before close */
245 #define TCP_SENDMOREACKS        0x103   /* always ack every other packet */
246 #define TCP_ENABLE_ECN          0x104   /* Enable ECN on a connection */
247 #define TCP_FASTOPEN            0x105   /* Enable/Disable TCP Fastopen on this socket */
248 #define TCP_CONNECTION_INFO     0x106   /* State of TCP connection */
249 
250 #ifdef PRIVATE
251 /* See tcp_private.h for additional options */
252 #endif /* PRIVATE */
253 
254 
255 #define TCP_NOTSENT_LOWAT       0x201   /* Low water mark for TCP unsent data */
256 
257 struct tcp_connection_info {
258 	u_int8_t        tcpi_state;     /* connection state */
259 	u_int8_t        tcpi_snd_wscale; /* Window scale for send window */
260 	u_int8_t        tcpi_rcv_wscale; /* Window scale for receive window */
261 	u_int8_t        __pad1;
262 	u_int32_t       tcpi_options;   /* TCP options supported */
263 #define TCPCI_OPT_TIMESTAMPS    0x00000001 /* Timestamps enabled */
264 #define TCPCI_OPT_SACK          0x00000002 /* SACK enabled */
265 #define TCPCI_OPT_WSCALE        0x00000004 /* Window scaling enabled */
266 #define TCPCI_OPT_ECN           0x00000008 /* ECN enabled */
267 	u_int32_t       tcpi_flags;     /* flags */
268 #define TCPCI_FLAG_LOSSRECOVERY 0x00000001
269 #define TCPCI_FLAG_REORDERING_DETECTED  0x00000002
270 	u_int32_t       tcpi_rto;       /* retransmit timeout in ms */
271 	u_int32_t       tcpi_maxseg;    /* maximum segment size supported */
272 	u_int32_t       tcpi_snd_ssthresh; /* slow start threshold in bytes */
273 	u_int32_t       tcpi_snd_cwnd;  /* send congestion window in bytes */
274 	u_int32_t       tcpi_snd_wnd;   /* send widnow in bytes */
275 	u_int32_t       tcpi_snd_sbbytes; /* bytes in send socket buffer, including in-flight data */
276 	u_int32_t       tcpi_rcv_wnd;   /* receive window in bytes*/
277 	u_int32_t       tcpi_rttcur;    /* most recent RTT in ms */
278 	u_int32_t       tcpi_srtt;      /* average RTT in ms */
279 	u_int32_t       tcpi_rttvar;    /* RTT variance */
280 	u_int32_t
281 	    tcpi_tfo_cookie_req:1,             /* Cookie requested? */
282 	    tcpi_tfo_cookie_rcv:1,             /* Cookie received? */
283 	    tcpi_tfo_syn_loss:1,               /* Fallback to reg. TCP after SYN-loss */
284 	    tcpi_tfo_syn_data_sent:1,             /* SYN+data has been sent out */
285 	    tcpi_tfo_syn_data_acked:1,             /* SYN+data has been fully acknowledged */
286 	    tcpi_tfo_syn_data_rcv:1,             /* Server received SYN+data with a valid cookie */
287 	    tcpi_tfo_cookie_req_rcv:1,             /* Server received cookie-request */
288 	    tcpi_tfo_cookie_sent:1,             /* Server announced cookie */
289 	    tcpi_tfo_cookie_invalid:1,             /* Server received an invalid cookie */
290 	    tcpi_tfo_cookie_wrong:1,             /* Our sent cookie was wrong */
291 	    tcpi_tfo_no_cookie_rcv:1,             /* We did not receive a cookie upon our request */
292 	    tcpi_tfo_heuristics_disable:1,             /* TFO-heuristics disabled it */
293 	    tcpi_tfo_send_blackhole:1,             /* A sending-blackhole got detected */
294 	    tcpi_tfo_recv_blackhole:1,             /* A receiver-blackhole got detected */
295 	    tcpi_tfo_onebyte_proxy:1,             /* A proxy acknowledges all but one byte of the SYN */
296 	    __pad2:17;
297 	u_int64_t       tcpi_txpackets __attribute__((aligned(8)));
298 	u_int64_t       tcpi_txbytes __attribute__((aligned(8)));
299 	u_int64_t       tcpi_txretransmitbytes __attribute__((aligned(8)));
300 	u_int64_t       tcpi_rxpackets __attribute__((aligned(8)));
301 	u_int64_t       tcpi_rxbytes __attribute__((aligned(8)));
302 	u_int64_t       tcpi_rxoutoforderbytes __attribute__((aligned(8)));
303 	u_int64_t       tcpi_txretransmitpackets __attribute__((aligned(8)));
304 };
305 #endif /* (_POSIX_C_SOURCE && !_DARWIN_C_SOURCE) */
306 
307 #ifdef PRIVATE
308 #include <netinet/tcp_private.h>
309 #endif
310 
311 #endif
312