/* * Copyright (c) 1982, 1986, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)tcp.h 8.1 (Berkeley) 6/10/93 * $FreeBSD: src/sys/netinet/tcp.h,v 1.13.2.3 2001/03/01 22:08:42 jlemon Exp $ */ #ifndef _NETINET_TCP_H_ #define _NETINET_TCP_H_ #include #if __BSD_VISIBLE #include typedef uint32_t tcp_seq; typedef int32_t tcp_seq_diff_t; #define tcp6_seq tcp_seq /* for KAME src sync over BSD*'s */ #define tcp6hdr tcphdr /* for KAME src sync over BSD*'s */ /* * TCP header. * Per RFC 793, September, 1981. */ struct tcphdr { u_short th_sport; /* source port */ u_short th_dport; /* destination port */ tcp_seq th_seq; /* sequence number */ tcp_seq th_ack; /* acknowledgement number */ #if _BYTE_ORDER == _LITTLE_ENDIAN u_int th_x2:4, /* (unused) */ th_off:4; /* data offset */ #elif _BYTE_ORDER == _BIG_ENDIAN u_int th_off:4, /* data offset */ th_x2:4; /* (unused) */ #else #error "Byte order not implemented" #endif u_char th_flags; #define TH_FIN 0x01 #define TH_SYN 0x02 #define TH_RST 0x04 #define TH_PUSH 0x08 #define TH_ACK 0x10 #define TH_URG 0x20 #define TH_ECE 0x40 #define TH_CWR 0x80 #define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR) u_short th_win; /* window */ u_short th_sum; /* checksum */ u_short th_urp; /* urgent pointer */ }; #define TCPOPT_EOL 0 #define TCPOPT_NOP 1 #define TCPOPT_2NOPs (TCPOPT_NOP << 24 | TCPOPT_NOP << 16) #define TCPOPT_MAXSEG 2 #define TCPOLEN_MAXSEG 4 #define TCPOPT_WINDOW 3 #define TCPOLEN_WINDOW 3 #define TCPOPT_SACK_PERMITTED 4 #define TCPOLEN_SACK_PERMITTED 2 #define TCPOPT_SACK_PERMITTED_ALIGNED \ (TCPOPT_2NOPs | TCPOPT_SACK_PERMITTED << 8 | TCPOLEN_SACK_PERMITTED) #define TCPOLEN_SACK_PERMITTED_ALIGNED 4 #define TCPOPT_SACK 5 #define TCPOLEN_SACK 2 #define TCPOLEN_SACK_BLOCK 8 #define TCPOPT_SACK_ALIGNED (TCPOPT_2NOPs | TCPOPT_SACK << 8) #define TCPOLEN_SACK_ALIGNED 4 #define TCPOPT_TIMESTAMP 8 #define TCPOLEN_TIMESTAMP 10 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ #define TCPOPT_TSTAMP_HDR \ (TCPOPT_2NOPs | TCPOPT_TIMESTAMP << 8 | TCPOLEN_TIMESTAMP) #define TCPOPT_CC 11 /* CC options: RFC-1644 */ #define TCPOPT_CCNEW 12 #define TCPOPT_CCECHO 13 #define TCPOPT_SIGNATURE 19 /* Keyed MD5: RFC 2385 */ #define TCPOLEN_SIGNATURE 18 /* * Default maximum segment size for TCP. * With an IP MSS of 576, this is 536, * but 512 is probably more convenient. * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). */ #define TCP_MSS 512 /* * TCP_MINMSS is defined to be 256 which is fine for the smallest * link MTU (296 bytes, SLIP interface) in the Internet. * However it is very unlikely to come across such low MTU interfaces * these days (anno dato 2003). * Probably it can be set to 512 without ill effects. But we play safe. * See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. * Setting this to "0" disables the minmss check. */ #define TCP_MINMSS 256 /* * Default maximum segment size for TCP6. * With an IP6 MSS of 1280, this is 1220, * but 1024 is probably more convenient. (xxx kazu in doubt) * This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr)) * * NOTE: TCP_MIN_WINSHIFT is used when negotiating window scaling. Larger * values are possible but apparently some firewires blows up if * values larger then 5 are used, so use 5. */ #define TCP6_MSS 1024 #define TCP_MAXWIN 65535 /* max value for (unscaled) window */ #define TCP_MIN_WINSHIFT 5 /* requested minimum (x32) */ #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ #define TCP_MAXBURST 4 /* maximum segments in a burst */ #define TCP_MAXHLEN (0xf<<2) /* max length of header in bytes */ #define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr)) /* max space left for options */ #endif /* __BSD_VISIBLE */ /* * User-settable options (used with setsockopt). */ #define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ #if __BSD_VISIBLE #define TCP_MAXSEG 0x02 /* set maximum segment size */ #define TCP_NOPUSH 0x04 /* don't push last block of write */ #define TCP_NOOPT 0x08 /* don't use TCP options */ #define TCP_SIGNATURE_ENABLE 0x10 /* use MD5 digests (RFC2385) */ #define TCP_KEEPINIT 0x20 /* set max time to establish connection */ /* 0x40 unused */ #define TCP_FASTKEEP 0x80 #define TCP_KEEPIDLE 0x100 /* set time before keepalive probes begin */ #define TCP_KEEPINTVL 0x200 /* set time between keepalive probes */ #define TCP_KEEPCNT 0x400 /* set max number of keepalive probes */ #endif /* __BSD_VISIBLE */ #endif