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1 /* |
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2 * Copyright (c) 1982, 1986, 1993, 1994 |
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3 * The Regents of the University of California. All rights reserved. |
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4 * |
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5 * Redistribution and use in source and binary forms, with or without |
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6 * modification, are permitted provided that the following conditions |
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7 * are met: |
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8 * 1. Redistributions of source code must retain the above copyright |
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9 * notice, this list of conditions and the following disclaimer. |
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10 * 2. Redistributions in binary form must reproduce the above copyright |
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11 * notice, this list of conditions and the following disclaimer in the |
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12 * documentation and/or other materials provided with the distribution. |
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13 * 3. All advertising materials mentioning features or use of this software |
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14 * must display the following acknowledgement: |
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15 * This product includes software developed by the University of |
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16 * California, Berkeley and its contributors. |
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17 * 4. Neither the name of the University nor the names of its contributors |
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18 * may be used to endorse or promote products derived from this software |
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19 * without specific prior written permission. |
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20 * |
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21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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31 * SUCH DAMAGE. |
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32 * |
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33 * @(#)tcp_var.h 8.3 (Berkeley) 4/10/94 |
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34 * tcp_var.h,v 1.3 1994/08/21 05:27:39 paul Exp |
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35 */ |
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36 |
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37 #ifndef _TCP_VAR_H_ |
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38 #define _TCP_VAR_H_ |
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39 |
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40 #include "tcpip.h" |
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41 #include "tcp_timer.h" |
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42 |
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43 #if SIZEOF_CHAR_P == 4 |
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44 typedef struct tcpiphdr *tcpiphdrp_32; |
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45 #else |
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46 typedef u_int32_t tcpiphdrp_32; |
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47 #endif |
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48 |
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49 /* |
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50 * Tcp control block, one per tcp; fields: |
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51 */ |
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52 struct tcpcb { |
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53 tcpiphdrp_32 seg_next; /* sequencing queue */ |
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54 tcpiphdrp_32 seg_prev; |
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55 short t_state; /* state of this connection */ |
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56 short t_timer[TCPT_NTIMERS]; /* tcp timers */ |
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57 short t_rxtshift; /* log(2) of rexmt exp. backoff */ |
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58 short t_rxtcur; /* current retransmit value */ |
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59 short t_dupacks; /* consecutive dup acks recd */ |
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60 u_short t_maxseg; /* maximum segment size */ |
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61 char t_force; /* 1 if forcing out a byte */ |
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62 u_short t_flags; |
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63 #define TF_ACKNOW 0x0001 /* ack peer immediately */ |
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64 #define TF_DELACK 0x0002 /* ack, but try to delay it */ |
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65 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ |
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66 #define TF_NOOPT 0x0008 /* don't use tcp options */ |
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67 #define TF_SENTFIN 0x0010 /* have sent FIN */ |
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68 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ |
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69 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ |
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70 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ |
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71 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ |
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72 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ |
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73 |
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74 /* Make it static for now */ |
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75 /* struct tcpiphdr *t_template; / * skeletal packet for transmit */ |
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76 struct tcpiphdr t_template; |
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77 |
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78 struct socket *t_socket; /* back pointer to socket */ |
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79 /* |
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80 * The following fields are used as in the protocol specification. |
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81 * See RFC783, Dec. 1981, page 21. |
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82 */ |
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83 /* send sequence variables */ |
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84 tcp_seq snd_una; /* send unacknowledged */ |
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85 tcp_seq snd_nxt; /* send next */ |
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86 tcp_seq snd_up; /* send urgent pointer */ |
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87 tcp_seq snd_wl1; /* window update seg seq number */ |
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88 tcp_seq snd_wl2; /* window update seg ack number */ |
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89 tcp_seq iss; /* initial send sequence number */ |
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90 u_int32_t snd_wnd; /* send window */ |
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91 /* receive sequence variables */ |
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92 u_int32_t rcv_wnd; /* receive window */ |
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93 tcp_seq rcv_nxt; /* receive next */ |
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94 tcp_seq rcv_up; /* receive urgent pointer */ |
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95 tcp_seq irs; /* initial receive sequence number */ |
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96 /* |
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97 * Additional variables for this implementation. |
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98 */ |
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99 /* receive variables */ |
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100 tcp_seq rcv_adv; /* advertised window */ |
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101 /* retransmit variables */ |
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102 tcp_seq snd_max; /* highest sequence number sent; |
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103 * used to recognize retransmits |
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104 */ |
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105 /* congestion control (for slow start, source quench, retransmit after loss) */ |
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106 u_int32_t snd_cwnd; /* congestion-controlled window */ |
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107 u_int32_t snd_ssthresh; /* snd_cwnd size threshold for |
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108 * for slow start exponential to |
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109 * linear switch |
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110 */ |
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111 /* |
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112 * transmit timing stuff. See below for scale of srtt and rttvar. |
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113 * "Variance" is actually smoothed difference. |
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114 */ |
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115 short t_idle; /* inactivity time */ |
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116 short t_rtt; /* round trip time */ |
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117 tcp_seq t_rtseq; /* sequence number being timed */ |
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118 short t_srtt; /* smoothed round-trip time */ |
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119 short t_rttvar; /* variance in round-trip time */ |
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120 u_short t_rttmin; /* minimum rtt allowed */ |
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121 u_int32_t max_sndwnd; /* largest window peer has offered */ |
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122 |
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123 /* out-of-band data */ |
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124 char t_oobflags; /* have some */ |
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125 char t_iobc; /* input character */ |
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126 #define TCPOOB_HAVEDATA 0x01 |
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127 #define TCPOOB_HADDATA 0x02 |
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128 short t_softerror; /* possible error not yet reported */ |
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129 |
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130 /* RFC 1323 variables */ |
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131 u_char snd_scale; /* window scaling for send window */ |
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132 u_char rcv_scale; /* window scaling for recv window */ |
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133 u_char request_r_scale; /* pending window scaling */ |
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134 u_char requested_s_scale; |
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135 u_int32_t ts_recent; /* timestamp echo data */ |
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136 u_int32_t ts_recent_age; /* when last updated */ |
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137 tcp_seq last_ack_sent; |
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138 |
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139 }; |
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140 |
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141 #define sototcpcb(so) ((so)->so_tcpcb) |
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142 |
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143 /* |
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144 * The smoothed round-trip time and estimated variance |
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145 * are stored as fixed point numbers scaled by the values below. |
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146 * For convenience, these scales are also used in smoothing the average |
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147 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). |
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148 * With these scales, srtt has 3 bits to the right of the binary point, |
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149 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the |
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150 * binary point, and is smoothed with an ALPHA of 0.75. |
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151 */ |
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152 #define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */ |
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153 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ |
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154 #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */ |
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155 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ |
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156 |
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157 /* |
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158 * The initial retransmission should happen at rtt + 4 * rttvar. |
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159 * Because of the way we do the smoothing, srtt and rttvar |
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160 * will each average +1/2 tick of bias. When we compute |
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161 * the retransmit timer, we want 1/2 tick of rounding and |
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162 * 1 extra tick because of +-1/2 tick uncertainty in the |
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163 * firing of the timer. The bias will give us exactly the |
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164 * 1.5 tick we need. But, because the bias is |
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165 * statistical, we have to test that we don't drop below |
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166 * the minimum feasible timer (which is 2 ticks). |
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167 * This macro assumes that the value of TCP_RTTVAR_SCALE |
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168 * is the same as the multiplier for rttvar. |
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169 */ |
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170 #define TCP_REXMTVAL(tp) \ |
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171 (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) |
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172 |
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173 /* XXX |
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174 * We want to avoid doing m_pullup on incoming packets but that |
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175 * means avoiding dtom on the tcp reassembly code. That in turn means |
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176 * keeping an mbuf pointer in the reassembly queue (since we might |
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177 * have a cluster). As a quick hack, the source & destination |
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178 * port numbers (which are no longer needed once we've located the |
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179 * tcpcb) are overlayed with an mbuf pointer. |
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180 */ |
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181 #if SIZEOF_CHAR_P == 4 |
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182 typedef struct mbuf *mbufp_32; |
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183 #else |
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184 typedef u_int32_t mbufp_32; |
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185 #endif |
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186 #define REASS_MBUF(ti) (*(mbufp_32 *)&((ti)->ti_t)) |
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187 |
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188 #ifdef LOG_ENABLED |
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189 /* |
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190 * TCP statistics. |
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191 * Many of these should be kept per connection, |
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192 * but that's inconvenient at the moment. |
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193 */ |
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194 struct tcpstat { |
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195 u_long tcps_connattempt; /* connections initiated */ |
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196 u_long tcps_accepts; /* connections accepted */ |
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197 u_long tcps_connects; /* connections established */ |
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198 u_long tcps_drops; /* connections dropped */ |
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199 u_long tcps_conndrops; /* embryonic connections dropped */ |
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200 u_long tcps_closed; /* conn. closed (includes drops) */ |
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201 u_long tcps_segstimed; /* segs where we tried to get rtt */ |
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202 u_long tcps_rttupdated; /* times we succeeded */ |
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203 u_long tcps_delack; /* delayed acks sent */ |
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204 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ |
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205 u_long tcps_rexmttimeo; /* retransmit timeouts */ |
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206 u_long tcps_persisttimeo; /* persist timeouts */ |
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207 u_long tcps_keeptimeo; /* keepalive timeouts */ |
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208 u_long tcps_keepprobe; /* keepalive probes sent */ |
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209 u_long tcps_keepdrops; /* connections dropped in keepalive */ |
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210 |
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211 u_long tcps_sndtotal; /* total packets sent */ |
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212 u_long tcps_sndpack; /* data packets sent */ |
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213 u_long tcps_sndbyte; /* data bytes sent */ |
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214 u_long tcps_sndrexmitpack; /* data packets retransmitted */ |
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215 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ |
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216 u_long tcps_sndacks; /* ack-only packets sent */ |
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217 u_long tcps_sndprobe; /* window probes sent */ |
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218 u_long tcps_sndurg; /* packets sent with URG only */ |
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219 u_long tcps_sndwinup; /* window update-only packets sent */ |
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220 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ |
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221 |
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222 u_long tcps_rcvtotal; /* total packets received */ |
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223 u_long tcps_rcvpack; /* packets received in sequence */ |
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224 u_long tcps_rcvbyte; /* bytes received in sequence */ |
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225 u_long tcps_rcvbadsum; /* packets received with ccksum errs */ |
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226 u_long tcps_rcvbadoff; /* packets received with bad offset */ |
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227 /* u_long tcps_rcvshort; */ /* packets received too short */ |
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228 u_long tcps_rcvduppack; /* duplicate-only packets received */ |
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229 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ |
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230 u_long tcps_rcvpartduppack; /* packets with some duplicate data */ |
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231 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ |
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232 u_long tcps_rcvoopack; /* out-of-order packets received */ |
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233 u_long tcps_rcvoobyte; /* out-of-order bytes received */ |
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234 u_long tcps_rcvpackafterwin; /* packets with data after window */ |
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235 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ |
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236 u_long tcps_rcvafterclose; /* packets rcvd after "close" */ |
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237 u_long tcps_rcvwinprobe; /* rcvd window probe packets */ |
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238 u_long tcps_rcvdupack; /* rcvd duplicate acks */ |
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239 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ |
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240 u_long tcps_rcvackpack; /* rcvd ack packets */ |
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241 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ |
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242 u_long tcps_rcvwinupd; /* rcvd window update packets */ |
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243 /* u_long tcps_pawsdrop; */ /* segments dropped due to PAWS */ |
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244 u_long tcps_predack; /* times hdr predict ok for acks */ |
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245 u_long tcps_preddat; /* times hdr predict ok for data pkts */ |
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246 u_long tcps_socachemiss; /* tcp_last_so misses */ |
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247 u_long tcps_didnuttin; /* Times tcp_output didn't do anything XXX */ |
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248 }; |
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249 |
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250 extern struct tcpstat tcpstat; /* tcp statistics */ |
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251 #endif |
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252 |
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253 extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ |
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254 |
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255 #endif |