1 | /*
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2 | * TINET (TCP/IP Protocol Stack)
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3 | *
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4 | * Copyright (C) 2001-2009 by Dep. of Computer Science and Engineering
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5 | * Tomakomai National College of Technology, JAPAN
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6 | *
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7 | * ä¸è¨èä½æ¨©è
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8 | ã¯ï¼ä»¥ä¸ã® (1)ï½(4) ã®æ¡ä»¶ãï¼Free Software Foundation
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9 | * ã«ãã£ã¦å
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10 | ¬è¡¨ããã¦ãã GNU General Public License ã® Version 2 ã«è¨
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11 | * è¿°ããã¦ããæ¡ä»¶ãæºããå ´åã«éãï¼æ¬ã½ããã¦ã§ã¢ï¼æ¬ã½ããã¦ã§ã¢
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12 | * ãæ¹å¤ãããã®ãå«ãï¼ä»¥ä¸åãï¼ã使ç¨ã»è¤è£½ã»æ¹å¤ã»åé
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13 | å¸ï¼ä»¥ä¸ï¼
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14 | * å©ç¨ã¨å¼ã¶ï¼ãããã¨ãç¡åã§è¨±è«¾ããï¼
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15 | * (1) æ¬ã½ããã¦ã§ã¢ãã½ã¼ã¹ã³ã¼ãã®å½¢ã§å©ç¨ããå ´åã«ã¯ï¼ä¸è¨ã®èä½
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16 | * 権表示ï¼ãã®å©ç¨æ¡ä»¶ããã³ä¸è¨ã®ç¡ä¿è¨¼è¦å®ãï¼ãã®ã¾ã¾ã®å½¢ã§ã½ã¼
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17 | * ã¹ã³ã¼ãä¸ã«å«ã¾ãã¦ãããã¨ï¼
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18 | * (2) æ¬ã½ããã¦ã§ã¢ãï¼ã©ã¤ãã©ãªå½¢å¼ãªã©ï¼ä»ã®ã½ããã¦ã§ã¢éçºã«ä½¿
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19 | * ç¨ã§ããå½¢ã§åé
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20 | å¸ããå ´åã«ã¯ï¼åé
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21 | å¸ã«ä¼´ãããã¥ã¡ã³ãï¼å©ç¨
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22 | * è
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23 | ããã¥ã¢ã«ãªã©ï¼ã«ï¼ä¸è¨ã®èä½æ¨©è¡¨ç¤ºï¼ãã®å©ç¨æ¡ä»¶ããã³ä¸è¨
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24 | * ã®ç¡ä¿è¨¼è¦å®ãæ²è¼ãããã¨ï¼
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25 | * (3) æ¬ã½ããã¦ã§ã¢ãï¼æ©å¨ã«çµã¿è¾¼ããªã©ï¼ä»ã®ã½ããã¦ã§ã¢éçºã«ä½¿
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26 | * ç¨ã§ããªãå½¢ã§åé
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27 | å¸ããå ´åã«ã¯ï¼æ¬¡ã®æ¡ä»¶ãæºãããã¨ï¼
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28 | * (a) åé
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29 | å¸ã«ä¼´ãããã¥ã¡ã³ãï¼å©ç¨è
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30 | ããã¥ã¢ã«ãªã©ï¼ã«ï¼ä¸è¨ã®è
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31 | * ä½æ¨©è¡¨ç¤ºï¼ãã®å©ç¨æ¡ä»¶ããã³ä¸è¨ã®ç¡ä¿è¨¼è¦å®ãæ²è¼ãããã¨ï¼
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32 | * (4) æ¬ã½ããã¦ã§ã¢ã®å©ç¨ã«ããç´æ¥çã¾ãã¯éæ¥çã«çãããããªãæ
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33 | * 害ãããï¼ä¸è¨èä½æ¨©è
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34 | ããã³TOPPERSããã¸ã§ã¯ããå
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35 | 責ãããã¨ï¼
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36 | *
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37 | * æ¬ã½ããã¦ã§ã¢ã¯ï¼ç¡ä¿è¨¼ã§æä¾ããã¦ãããã®ã§ããï¼ä¸è¨èä½æ¨©è
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38 | ã
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39 | * ãã³TOPPERSããã¸ã§ã¯ãã¯ï¼æ¬ã½ããã¦ã§ã¢ã«é¢ãã¦ï¼ãã®é©ç¨å¯è½æ§ã
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40 | * å«ãã¦ï¼ãããªãä¿è¨¼ãè¡ããªãï¼ã¾ãï¼æ¬ã½ããã¦ã§ã¢ã®å©ç¨ã«ããç´
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41 | * æ¥çã¾ãã¯éæ¥çã«çãããããªãæ害ã«é¢ãã¦ãï¼ãã®è²¬ä»»ãè² ããªãï¼
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42 | *
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43 | * @(#) $Id: tcp_input.c 270 2017-02-09 04:03:47Z coas-nagasima $
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44 | */
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45 |
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46 | /*
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47 | * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1994, 1995
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48 | * The Regents of the University of California. All rights reserved.
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49 | *
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50 | * Redistribution and use in source and binary forms, with or without
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51 | * modification, are permitted provided that the following conditions
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52 | * are met:
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53 | * 1. Redistributions of source code must retain the above copyright
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54 | * notice, this list of conditions and the following disclaimer.
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55 | * 2. Redistributions in binary form must reproduce the above copyright
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56 | * notice, this list of conditions and the following disclaimer in the
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57 | * documentation and/or other materials provided with the distribution.
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58 | * 3. All advertising materials mentioning features or use of this software
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59 | * must display the following acknowledgement:
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60 | * This product includes software developed by the University of
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61 | * California, Berkeley and its contributors.
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62 | * 4. Neither the name of the University nor the names of its contributors
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63 | * may be used to endorse or promote products derived from this software
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64 | * without specific prior written permission.
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65 | *
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66 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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67 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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68 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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69 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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70 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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71 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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72 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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73 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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74 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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75 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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76 | * SUCH DAMAGE.
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77 | *
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78 | * @(#)tcp_input.c 8.12 (Berkeley) 5/24/95
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79 | * $FreeBSD: src/sys/netinet/tcp_input.c,v 1.82.2.3 1999/10/14 11:49:38 des Exp $
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80 | */
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81 |
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82 | #include <string.h>
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83 |
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84 | #ifdef TARGET_KERNEL_ASP
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85 |
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86 | #include <kernel.h>
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87 | #include <sil.h>
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88 | #include <t_syslog.h>
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89 | #include "kernel_cfg.h"
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90 |
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91 | #endif /* of #ifdef TARGET_KERNEL_ASP */
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92 |
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93 | #ifdef TARGET_KERNEL_JSP
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94 |
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95 | #include <s_services.h>
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96 | #include <t_services.h>
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97 | #include "kernel_id.h"
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98 |
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99 | #endif /* of #ifdef TARGET_KERNEL_JSP */
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100 |
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101 | #include <tinet_defs.h>
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102 | #include <tinet_config.h>
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103 |
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104 | #include <net/if.h>
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105 | #include <net/if_ppp.h>
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106 | #include <net/if_loop.h>
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107 | #include <net/ethernet.h>
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108 | #include <net/net.h>
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109 | #include <net/net_var.h>
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110 | #include <net/net_buf.h>
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111 | #include <net/net_timer.h>
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112 | #include <net/net_count.h>
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113 |
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114 | #include <netinet/in.h>
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115 | #include <netinet/in_var.h>
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116 | #include <netinet6/in6.h>
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117 | #include <netinet6/in6_var.h>
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118 | #include <netinet6/nd6.h>
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119 | #include <netinet/in_itron.h>
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120 | #include <netinet/ip.h>
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121 | #include <netinet/ip_var.h>
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122 | #include <netinet/ip6.h>
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123 | #include <netinet6/ip6_var.h>
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124 | #include <netinet/ip_icmp.h>
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125 | #include <netinet/tcp.h>
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126 | #include <netinet/tcp_timer.h>
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127 | #include <netinet/tcp_var.h>
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128 | #include <netinet/tcp_fsm.h>
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129 | #include <netinet/tcp_seq.h>
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130 |
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131 | #ifdef SUPPORT_TCP
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132 |
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133 | /*
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134 | * æ»ãå¤
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135 | *
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136 | * RET_OK æ£å¸¸
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137 | * RET_DROP ã¨ã©ã¼ãã»ã°ã¡ã³ããç ´æ£ããã
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138 | * RET_RST_DROP ã¨ã©ã¼ãRST ãéä¿¡ããã»ã°ã¡ã³ããç ´æ£ããã
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139 | */
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140 |
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141 | #define RET_OK (0)
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142 | #define RET_NEED_OUTPUT (1)
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143 | #define RET_RETURN (2)
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144 | #define RET_DROP (-1)
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145 | #define RET_RST_DROP (-2)
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146 |
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147 | /*
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148 | * é¢æ°
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149 | */
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150 |
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151 | static void close_connection (T_TCP_CEP *cep, bool_t *needoutput);
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152 | static void set_rexmt_timer (T_TCP_CEP *cep, T_TCP_TIME rtt);
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153 | static uint8_t reassemble (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, uint8_t flags);
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154 | static ER drop_after_ack (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff);
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155 | static ER listening (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, T_TCP_SEQ iss);
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156 | static ER proc_ack1 (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, bool_t *needoutput);
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157 | static ER proc_ack2 (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, bool_t *needoutput);
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158 | static ER syn_sent (T_TCP_HDR *tcph, T_TCP_CEP *cep);
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159 | static void trim_length (T_TCP_HDR *tcph, T_TCP_CEP *cep);
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160 | static void parse_option (T_TCP_HDR *tcph, T_TCP_CEP *cep);
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161 | static bool_t update_wnd (T_TCP_HDR *tcph, T_TCP_CEP *cep);
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162 | static void proc_urg (T_TCP_HDR *tcph, T_TCP_CEP *cep);
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163 |
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164 | #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0
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165 |
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166 | /*
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167 | * ã¿ã¹ã¯ããã® Time Wait ç¶æ
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168 | CEP åé¢æ©è½
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169 | */
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170 |
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171 | /*
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172 | * é¢æ°
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173 | */
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174 |
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175 | static T_TCP_TWCEP*tcp_find_twcep (T_IN_ADDR *dstaddr, uint16_t dstport,
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176 | T_IN_ADDR *peeraddr, uint16_t peerport);
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177 |
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178 | /*
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179 | * å¤æ°
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180 | */
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181 |
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182 | T_TCP_TWCEP tcp_twcep[NUM_TCP_TW_CEP_ENTRY];
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183 |
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184 | /*
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185 | * tcp_find_twcep -- ãã¼ãçªå·ãã Time Wait ç¨ TCP é信端ç¹ãå¾ãã
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186 | *
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187 | * 注æ: dstaddr ã¯ããããã¯ã¼ã¯ãã¤ããªã¼ã
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188 | */
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189 |
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190 | static T_TCP_TWCEP*
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191 | tcp_find_twcep (T_IN_ADDR *dstaddr, uint16_t dstport, T_IN_ADDR *peeraddr, uint16_t peerport)
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192 | {
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193 | T_TCP_TWCEP* twcep;
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194 |
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195 | /*
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196 | * ç¶æ
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197 | ã TIME WAIT ã§ã
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198 | * IP ã¢ãã¬ã¹ã¨ãã¼ãçªå·ãä¸è´ããé信端ç¹ãæ¢ç´¢ããã
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199 | */
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200 | for (twcep = &tcp_twcep[NUM_TCP_TW_CEP_ENTRY]; twcep -- != tcp_twcep; ) {
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201 | if (twcep->fsm_state == TCP_FSM_TIME_WAIT &&
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202 | IN_IS_DSTADDR_ACCEPT (&twcep->myaddr.ipaddr, dstaddr) &&
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203 | IN_ARE_NET_ADDR_EQUAL(&twcep->dstaddr.ipaddr, peeraddr) &&
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204 | dstport == twcep->myaddr.portno &&
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205 | peerport == twcep->dstaddr.portno)
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206 | return twcep;
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207 | }
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208 |
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209 | return NULL;
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210 | }
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211 |
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212 | /*
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213 | * å¿
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214 | è¦ãªæ
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215 | å ±ã Time Wait ç¨ TCP é信端ç¹ã«ç§»ãã¦ã
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216 | * æ¨æºã® TCP é信端ç¹ãéæ¾ããã
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217 | */
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218 |
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219 | void
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220 | tcp_move_twcep (T_TCP_CEP *cep)
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221 | {
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222 | T_TCP_TWCEP* twcep;
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223 |
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224 | /* 空ãã® Time Wait ç¨ TCP é信端ç¹ãæ¢ç´¢ããã*/
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225 | for (twcep = &tcp_twcep[NUM_TCP_TW_CEP_ENTRY]; twcep -- != tcp_twcep; ) {
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226 | if (twcep->fsm_state != TCP_FSM_TIME_WAIT) {
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227 |
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228 | /*
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229 | * é信端ç¹ãããã¯ãã
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230 | * å¿
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231 | è¦ãªæ
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232 | å ±ã Time Wait ç¨ TCP é信端ç¹ã«ç§»ãã
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233 | */
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234 | syscall(wai_sem(cep->semid_lock));
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235 | twcep->rbufsz = cep->rbufsz;
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236 | twcep->dstaddr = cep->dstaddr;
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237 | twcep->myaddr = cep->myaddr;
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238 | twcep->snd_una = cep->snd_una;
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239 | twcep->rcv_nxt = cep->rcv_nxt;
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240 | twcep->rwbuf_count = cep->rwbuf_count;
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241 | twcep->fsm_state = cep->fsm_state;
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242 | twcep->timer_2msl = cep->timer[TCP_TIM_2MSL];
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243 |
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244 | /* é信端ç¹ãããã¯ã解é¤ããã*/
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245 | syscall(sig_sem(cep->semid_lock));
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246 |
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247 | /* æ¨æº TCP é信端ç¹ãéæ¾ããã*/
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248 | tcp_close(cep);
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249 |
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250 | break;
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251 | }
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252 | }
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253 | }
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254 |
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255 | #endif /* of #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0 */
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256 |
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257 | /*
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258 | * parse_option -- TCP ãããã®ãªãã·ã§ã³ã解æããã
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259 | */
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260 |
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261 | static void
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262 | parse_option (T_TCP_HDR *tcph, T_TCP_CEP *cep)
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263 | {
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264 | uint8_t *opt, type = 0;
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265 | uint_t len, ol, ssize;
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266 |
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267 | opt = (uint8_t*)tcph + TCP_HDR_SIZE;
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268 | len = (uint_t)(TCP_HDR_LEN(tcph->doff) - TCP_HDR_SIZE);
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269 | while (len > 0 && (type = *opt) != TCP_OPT_EOL) {
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270 | if (type == TCP_OPT_NOP)
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271 | ol = 1u;
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272 | else {
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273 | if (len < 2)
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274 | break;
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275 | ol = *(opt + 1);
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276 | if (ol < 2 || ol > len)
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277 | break;
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278 | }
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279 | switch (type) {
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280 | case TCP_OPT_NOP:
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281 | break;
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282 | case TCP_OPT_MAXSEG:
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283 | if ((ol == TCP_OPT_LEN_MAXSEG) && (tcph->flags & TCP_FLG_SYN)) {
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284 | ssize = ntohs(*(uint16_t*)(opt + 2));
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285 | if (ssize > MAX_TCP_SND_SEG)
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286 | cep->maxseg = MAX_TCP_SND_SEG;
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287 | else if (ssize < TCP_MINMSS)
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288 | cep->maxseg = TCP_MINMSS;
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289 | else
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290 | cep->maxseg = ssize;
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291 | }
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292 | break;
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293 |
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294 | case TCP_OPT_WINDOW:
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295 | case TCP_OPT_SACK_PERM:
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296 | case TCP_OPT_TIMESTAMP:
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297 | case TCP_OPT_CC:
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298 | case TCP_OPT_CCNEW:
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299 | case TCP_OPT_CCECHO:
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300 | syslog(LOG_INFO, "[TCP] unsup opt: %d.", type);
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301 | break;
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302 |
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303 | default:
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304 | syslog(LOG_NOTICE, "[TCP] unexp opt: %d.", type);
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305 | break;
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306 | }
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307 | opt += ol;
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308 | len -= ol;
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309 | }
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310 | }
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311 |
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312 | /*
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313 | * set_rexmt_timer -- æ°ããå¾å¾©æéãåéããåéã¿ã¤ããæ´æ°ããã
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314 | */
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315 |
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316 | static void
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317 | set_rexmt_timer (T_TCP_CEP *cep, T_TCP_TIME rtt)
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318 | {
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319 | T_TCP_TIME delta;
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320 |
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321 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RTT_UPDATES], 1);
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322 | if (cep->srtt != 0) {
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323 | /*
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324 | * srtt: å¹³æ»åããã RTT
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325 | *
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326 | * è¨æ¸¬ããã RTT (rtt) ã¨ç¾å¨ã®å¹³æ»åããã RTT (srtt) ã®å·® (delta) ãæ±ããã
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327 | *
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328 | * delta 㯠2 ãããå·¦ã·ãã ( 4 å) ããå¤ã§ä¿æããã
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329 | * srtt 㯠5 ãããå·¦ã·ãã (32 å) ããå¤ã§ä¿æããã¦ããã
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330 | *
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331 | * delta = rtt / 8 - srtt / 8
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332 | *
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333 | * æ°ãã srtt ã¯
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334 | *
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335 | * srtt = rtt / 8 + srtt * 7 / 8
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336 | * = srtt + (rtt / 8 - srtt / 8)
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337 | *
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338 | * ã§è¨ç®ããã
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339 | * ãã®ãããrtt ã 2 ãããå·¦ã·ããããsrtt ã (5 - 2) ãããå³ã·ããã㦠delta ãæ±ããã
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340 | */
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341 | delta = ((rtt - 1) << TCP_DELTA_SHIFT) - (cep->srtt >> (TCP_SRTT_SHIFT - TCP_DELTA_SHIFT));
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342 | cep->srtt += delta;
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343 | if (cep->srtt <= 0)
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344 | cep->srtt = 1;
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345 |
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346 | /*
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347 | * delta ã®çµ¶å¯¾å¤ | delta | ãæ±ããã
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348 | */
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349 | if (delta < 0)
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350 | delta = - delta;
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351 |
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352 | /*
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353 | * rttvar: å¹³æ»åãããåæ£
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354 | *
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355 | * rttvar 㯠4 ãããå·¦ã·ãã (16 å) ããå¤ã§ä¿æããã¦ããã
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356 | *
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357 | * delta = |delta| / 4 - rttvar / 4
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358 | *
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359 | * æ°ãã rttvar ã¯
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360 | *
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361 | * rttvar = |delta|/ 4 + rttvar * 3 /4
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362 | * = rttvar + (|delta| / 4 - rttvar / 4)
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363 | *
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364 | * ã§è¨ç®ããã
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365 | */
|
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366 | delta -= cep->rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
|
---|
367 | cep->rttvar += delta;
|
---|
368 | if (cep->rttvar <= 0)
|
---|
369 | cep->rttvar = 1;
|
---|
370 | }
|
---|
371 | else {
|
---|
372 | /*
|
---|
373 | * ã¾ã srtt ã®è¨å®ãè¡ããã¦ããªãã¨ãã¯ãä»åè¨æ¸¬ããã RTT ã使ç¨ããã
|
---|
374 | * å¹³æ»åããã RTT (srtt) ã«ã¯ãRTT ã 5 ãããå·¦ã·ãã (32å) ããå¤ã
|
---|
375 | * å¹³æ»åãããåæ£ (rttvar) ã«ã¯ãRTT ã® 1/2 ã 4 ãããå·¦ã·ãã (16å) ããå¤ã
|
---|
376 | */
|
---|
377 | cep->srtt = rtt << TCP_SRTT_SHIFT;
|
---|
378 | cep->rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
|
---|
379 | }
|
---|
380 |
|
---|
381 | /*
|
---|
382 | * rtt ã®æ¸¬å®ãçµäºããåéåæ°ããªã»ããããã
|
---|
383 | */
|
---|
384 | cep->rtt = cep->rxtshift = 0;
|
---|
385 |
|
---|
386 | /*
|
---|
387 | * RTT ã«è¨±ãããæå°å¤ 㨠rtt + 2 ã®å¤§ããªå¤ã®æ¹ãåéã¿ã¤ã ã¢ã¦ãã®æå°å¤ã«ããã
|
---|
388 | */
|
---|
389 | if (rtt + 2 < TCP_TVAL_MIN)
|
---|
390 | cep->rxtcur = tcp_range_set(tcp_rexmt_val(cep),
|
---|
391 | (T_TCP_TIME)TCP_TVAL_MIN,
|
---|
392 | (T_TCP_TIME)TCP_TVAL_MAX_REXMT);
|
---|
393 | else
|
---|
394 | cep->rxtcur = tcp_range_set(tcp_rexmt_val(cep),
|
---|
395 | (T_TCP_TIME)(rtt + 2),
|
---|
396 | (T_TCP_TIME)TCP_TVAL_MAX_REXMT);
|
---|
397 | }
|
---|
398 |
|
---|
399 | /*
|
---|
400 | * reassemble -- åä¿¡ã»ã°ã¡ã³ããåæ§æãããé çªéãã«åä¿¡ããã¨ãã®å¦ç
|
---|
401 | */
|
---|
402 |
|
---|
403 | static uint8_t
|
---|
404 | reassemble (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, uint8_t flags)
|
---|
405 | {
|
---|
406 | T_TCP_Q_HDR *qhdr;
|
---|
407 | T_TCP_HDR *tcph;
|
---|
408 |
|
---|
409 | tcph = GET_TCP_HDR(input, thoff);
|
---|
410 | if (tcph->sum > cep->rbufsz - cep->rwbuf_count) {
|
---|
411 | /*
|
---|
412 | * åä¿¡ã¦ã£ã³ããããã¡ã«ç©ºãããªãã¨ãã¯ç ´æ£ããã
|
---|
413 | */
|
---|
414 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_DROP_SEGS], 1);
|
---|
415 | syscall(rel_net_buf(input));
|
---|
416 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
417 | flags &= ~TCP_FLG_FIN;
|
---|
418 | }
|
---|
419 | else if (tcph->seq == cep->rcv_nxt &&
|
---|
420 | cep->reassq == NULL &&
|
---|
421 | cep->fsm_state == TCP_FSM_ESTABLISHED) {
|
---|
422 | /*
|
---|
423 | * é çªéãã«ã»ã°ã¡ã³ããåä¿¡ããæã®å¦ç
|
---|
424 | * åä¿¡ã»ã°ã¡ã³ãã®ä¸¦ã¹æ¿ãã¯ä¸è¦ãªã®ã§
|
---|
425 | * ãã®ã¾ã¾åä¿¡ã¦ã£ã³ããããã¡ã«æ¸ãè¾¼ãã
|
---|
426 | */
|
---|
427 |
|
---|
428 | #ifdef TCP_CFG_DELAY_ACK
|
---|
429 |
|
---|
430 | cep->flags |= TCP_CEP_FLG_DEL_ACK;
|
---|
431 |
|
---|
432 | #else/* of #ifdef TCP_CFG_DELAY_ACK */
|
---|
433 |
|
---|
434 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
435 |
|
---|
436 | #endif/* of #ifdef TCP_CFG_DELAY_ACK */
|
---|
437 |
|
---|
438 | qhdr = GET_TCP_Q_HDR(input, thoff);
|
---|
439 |
|
---|
440 | /* TCP ãããã®ä½ç½®ãä¿åããã*/
|
---|
441 | GET_TCP_IP_Q_HDR(input)->thoff = thoff;
|
---|
442 |
|
---|
443 | /* SDU ã®ãªãã»ããï¼å
|
---|
444 | ã¯ã¦ã£ã³ããµã¤ãºï¼ããªã»ããããã*/
|
---|
445 | qhdr->soff = 0;
|
---|
446 |
|
---|
447 | /* ãã¼ã¿ãåä¿¡ã¦ã£ã³ããããã¡ã«æ¸ãè¾¼ãã*/
|
---|
448 | TCP_WRITE_RWBUF(cep, input, thoff);
|
---|
449 | }
|
---|
450 | else {
|
---|
451 | flags = tcp_write_raque(input, cep, thoff, flags);
|
---|
452 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
453 | }
|
---|
454 | return flags;
|
---|
455 | }
|
---|
456 |
|
---|
457 | /*
|
---|
458 | * listening -- ååãªã¼ãã³ãã¦ï¼ç¶æ
|
---|
459 | ã LISTEN ã®å¦ç
|
---|
460 | *
|
---|
461 | * æ»ãå¤:
|
---|
462 | * RET_OK æ£å¸¸
|
---|
463 | * RET_DROP ã¨ã©ã¼ãã»ã°ã¡ã³ããç ´æ£ããã
|
---|
464 | * RET_RST_DROP ã¨ã©ã¼ãRST ãéä¿¡ããã»ã°ã¡ã³ããç ´æ£ããã
|
---|
465 | */
|
---|
466 |
|
---|
467 | static ER
|
---|
468 | listening (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, T_TCP_SEQ iss)
|
---|
469 | {
|
---|
470 | T_IP_HDR *iph;
|
---|
471 | T_TCP_HDR *tcph;
|
---|
472 |
|
---|
473 | iph = GET_IP_HDR(input);
|
---|
474 | tcph = GET_TCP_HDR(input, thoff);
|
---|
475 |
|
---|
476 | /*
|
---|
477 | * ãã©ã°ã« RST ãã»ããããã¦ããã°ç ´æ£ããã
|
---|
478 | */
|
---|
479 | if (tcph->flags & TCP_FLG_RST)
|
---|
480 | return RET_DROP;
|
---|
481 |
|
---|
482 | /*
|
---|
483 | * ãã©ã°ã« ACK ãã»ãããã¦ãããã°ã
|
---|
484 | * ãªã»ãããéã£ã¦ç ´æ£ããã
|
---|
485 | */
|
---|
486 | if (tcph->flags & TCP_FLG_ACK)
|
---|
487 | return RET_RST_DROP;
|
---|
488 |
|
---|
489 | /*
|
---|
490 | * ãã©ã°ã« SYN ãã»ããããã¦ããªããã°ãã°ç ´æ£ããã
|
---|
491 | */
|
---|
492 | if ((tcph->flags & TCP_FLG_SYN) == 0)
|
---|
493 | return RET_DROP;
|
---|
494 |
|
---|
495 | #if defined(SUPPORT_INET4)
|
---|
496 |
|
---|
497 | #ifdef SUPPORT_LOOP
|
---|
498 |
|
---|
499 | /*
|
---|
500 | * 次ã®ã¨ãã¯ç ´æ£ããã
|
---|
501 | * ã»ãã¼ãçªå·ãåä¸ã§ãéåä¿¡ IP ã¢ãã¬ã¹ ãåä¸ã
|
---|
502 | * ãã ãããã¼ã«ã«ã«ã¼ããã㯠(127.0.0.1) ãªãè¯ãã
|
---|
503 | * ã»ãã«ããã£ã¹ãã¢ãã¬ã¹
|
---|
504 | */
|
---|
505 |
|
---|
506 | if (tcph->dport == tcph->sport &&
|
---|
507 | (iph->dst == iph->src && ntohl(iph->src) != IPV4_ADDR_LOOPBACK))
|
---|
508 | return RET_DROP;
|
---|
509 |
|
---|
510 | #else /* of #ifdef SUPPORT_LOOP */
|
---|
511 |
|
---|
512 | /*
|
---|
513 | * 次ã®ã¨ãã¯ç ´æ£ããã
|
---|
514 | * ã»ãã¼ãçªå·ãåä¸ã§ãéåä¿¡ IP ã¢ãã¬ã¹ ãåä¸ã
|
---|
515 | * ã»ãã«ããã£ã¹ãã¢ãã¬ã¹
|
---|
516 | */
|
---|
517 |
|
---|
518 | if (tcph->dport == tcph->sport && iph->dst == iph->src)
|
---|
519 | return RET_DROP;
|
---|
520 |
|
---|
521 | #endif /* of #ifdef SUPPORT_LOOP */
|
---|
522 |
|
---|
523 | #endif /* of #if defined(SUPPORT_INET4) */
|
---|
524 |
|
---|
525 | #if defined(SUPPORT_INET6)
|
---|
526 |
|
---|
527 | /*
|
---|
528 | * 次ã®ã¨ãã¯ç ´æ£ããã
|
---|
529 | * ã»ãã¼ãçªå·ãåä¸ã§ãéåä¿¡ IP ã¢ãã¬ã¹ ãåä¸ã
|
---|
530 | * ã»ãã«ããã£ã¹ãã¢ãã¬ã¹
|
---|
531 | */
|
---|
532 |
|
---|
533 | if (tcph->dport == tcph->sport && IN_ARE_ADDR_EQUAL(&iph->dst, &iph->src))
|
---|
534 | return RET_DROP;
|
---|
535 |
|
---|
536 | #endif /* of #if defined(SUPPORT_INET6) */
|
---|
537 |
|
---|
538 | if (IN_IS_NET_ADDR_MULTICAST(&iph->dst))
|
---|
539 | return RET_DROP;
|
---|
540 |
|
---|
541 | /* ç¸æã®ã¢ãã¬ã¹ãè¨é²ããã*/
|
---|
542 | IN_COPY_TO_HOST(&cep->dstaddr.ipaddr, &iph->src);
|
---|
543 | cep->dstaddr.portno = tcph->sport;
|
---|
544 |
|
---|
545 | /* ãªãã·ã§ã³ãå¦çããã*/
|
---|
546 | parse_option(tcph, cep);
|
---|
547 |
|
---|
548 | /* ã·ã¼ã±ã³ã¹çªå·ãåæåããã*/
|
---|
549 | if (tcp_iss == 0)
|
---|
550 | tcp_init_iss();
|
---|
551 |
|
---|
552 | /* èªåã®ã·ã¼ã±ã³ã¹çªå·ã®åæå¤ãè¨é²ããã*/
|
---|
553 | if (iss != 0)
|
---|
554 | cep->iss = iss;
|
---|
555 | else
|
---|
556 | cep->iss = tcp_iss;
|
---|
557 |
|
---|
558 | tcp_iss += TCP_ISS_INCR() / 4;
|
---|
559 |
|
---|
560 | /* ç¸æã®ã·ã¼ã±ã³ã¹çªå·ã®åæå¤ãè¨é²ããã*/
|
---|
561 | cep->irs = tcph->seq;
|
---|
562 |
|
---|
563 | /* éåä¿¡ã·ã¼ã±ã³ã¹çªå·ãåæåããã*/
|
---|
564 | init_send_seq(cep);
|
---|
565 | init_receive_seq(cep);
|
---|
566 |
|
---|
567 | /* éä¿¡ã¦ã¤ã³ããµã¤ãºãè¨å®ããã*/
|
---|
568 | cep->snd_wnd = tcph->win;
|
---|
569 |
|
---|
570 | /* æçµè¨å® */
|
---|
571 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
572 | cep->fsm_state = TCP_FSM_SYN_RECVD;
|
---|
573 | cep->timer[TCP_TIM_KEEP] = TCP_TVAL_KEEP_INIT;
|
---|
574 |
|
---|
575 | return RET_OK;
|
---|
576 | }
|
---|
577 |
|
---|
578 | /*
|
---|
579 | * syn_sent -- è½åãªã¼ãã³ãã¦ãç¶æ
|
---|
580 | ã SYN éä¿¡æ¸ã®å¦ç
|
---|
581 | *
|
---|
582 | * æ»ãå¤:
|
---|
583 | * RET_OK æ£å¸¸
|
---|
584 | * RET_DROP ã¨ã©ã¼ãã»ã°ã¡ã³ããç ´æ£ããã
|
---|
585 | * RET_RST_DROP ã¨ã©ã¼ãRST ãéä¿¡ããã»ã°ã¡ã³ããç ´æ£ããã
|
---|
586 | */
|
---|
587 |
|
---|
588 | static ER
|
---|
589 | syn_sent (T_TCP_HDR *tcph, T_TCP_CEP *cep)
|
---|
590 | {
|
---|
591 | ER error = RET_OK;
|
---|
592 |
|
---|
593 | /*
|
---|
594 | * ç¸æããå信確èªãéããã¦æ¥ã¦ãã
|
---|
595 | *
|
---|
596 | * ACK <= iss && éä¿¡ããæ大 SEQ (snd_max) < ACK
|
---|
597 | *
|
---|
598 | * ãªãããªã»ãããéã£ã¦ã»ã°ã¡ã³ããç ´æ£ããã
|
---|
599 | */
|
---|
600 | if ((tcph->flags & TCP_FLG_ACK) &&
|
---|
601 | (SEQ_LE(tcph->ack, cep->iss) || SEQ_GT(tcph->ack, cep->snd_max)))
|
---|
602 | return RET_RST_DROP;
|
---|
603 |
|
---|
604 | /*
|
---|
605 | * RST/ACK ãã©ã°ã®å¿çãããã°ããã¼ããéãã¦ããªã
|
---|
606 | * ãã¨ãæå³ãã¦ããã
|
---|
607 | */
|
---|
608 | if (tcph->flags & TCP_FLG_RST) {
|
---|
609 | if (tcph->flags & TCP_FLG_ACK) {
|
---|
610 | cep->net_error = EV_CNNRF;
|
---|
611 | cep = tcp_drop(cep, E_CLS);
|
---|
612 | }
|
---|
613 | return RET_DROP;
|
---|
614 | }
|
---|
615 |
|
---|
616 | /*
|
---|
617 | * SYN ãã©ã°ããªããã°ã»ã°ã¡ã³ããç ´æ£ããã
|
---|
618 | */
|
---|
619 | if ((tcph->flags & TCP_FLG_SYN) == 0)
|
---|
620 | return RET_DROP;
|
---|
621 |
|
---|
622 | cep->snd_wnd = tcph->win; /* snd_wnd: ç¸æã®åä¿¡å¯è½ã¦ã£ã³ããµã¤ãº */
|
---|
623 | cep->irs = tcph->seq; /* irs: ç¸æã®ã·ã¼ã±ã³ã¹çªå·ã®åæå¤ */
|
---|
624 | init_receive_seq(cep); /* éåä¿¡ã·ã¼ã±ã³ã¹çªå·ãåæåããã */
|
---|
625 |
|
---|
626 | if (tcph->flags & TCP_FLG_ACK) {
|
---|
627 | /*
|
---|
628 | * ACK ãã©ã°ãããã¨ãã®å¦ç
|
---|
629 | *
|
---|
630 | * åä¿¡ãæå¾
|
---|
631 | ãã¦ããæ大㮠SEQ (rcv_adv) ã
|
---|
632 | * åä¿¡å¯è½ãªã¦ã£ã³ããµã¤ãº (rcv_wnd) åé²ããã
|
---|
633 | */
|
---|
634 | cep->rcv_adv += cep->rcv_wnd; /* rcv_adv: åä¿¡ãæå¾
|
---|
635 | ãã¦ããæ大㮠SEQ */
|
---|
636 | /* rcv_wnd: åä¿¡å¯è½ãªã¦ã£ã³ããµã¤ãº */
|
---|
637 |
|
---|
638 | /* æªç¢ºèªã®æå°éä¿¡ SEQ (snd_una) ã SYN å (1 ãªã¯ããã) é²ããã*/
|
---|
639 | cep->snd_una ++;
|
---|
640 |
|
---|
641 | #ifdef TCP_CFG_DELAY_ACK
|
---|
642 |
|
---|
643 | if (tcph->sum != 0) /* tcph->sum 㯠SDU é· */
|
---|
644 | cep->flags |= TCP_CEP_FLG_DEL_ACK;
|
---|
645 | else
|
---|
646 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
647 |
|
---|
648 | #else/* of #ifdef TCP_CFG_DELAY_ACK */
|
---|
649 |
|
---|
650 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
651 |
|
---|
652 | #endif/* of #ifdef TCP_CFG_DELAY_ACK */
|
---|
653 |
|
---|
654 | if (cep->flags & TCP_CEP_FLG_NEED_FIN) {
|
---|
655 | /*
|
---|
656 | * CEP 㧠FIN éä¿¡ãè¦æ±ããã¦ããã°ã
|
---|
657 | * åæå¦çãéå§ãã
|
---|
658 | * CEP ã®ç¶æ
|
---|
659 | ã FIN Wait 1 ã«ããã
|
---|
660 | */
|
---|
661 | cep->fsm_state = TCP_FSM_FIN_WAIT_1;
|
---|
662 | cep->flags &= ~TCP_CEP_FLG_NEED_FIN;
|
---|
663 | tcph->flags &= ~TCP_FLG_SYN;
|
---|
664 | }
|
---|
665 | else {
|
---|
666 | /*
|
---|
667 | * ç¸æãã ACK ãå¿çãããã®ã§ã
|
---|
668 | * CEP ã®ç¶æ
|
---|
669 | ã ã³ãã¯ã·ã§ã³éè¨å®äºç¶æ
|
---|
670 | ã«ããã
|
---|
671 | */
|
---|
672 | cep->timer[TCP_TIM_KEEP] = TCP_TVAL_KEEP_IDLE;
|
---|
673 | cep->fsm_state = TCP_FSM_ESTABLISHED;
|
---|
674 | NET_COUNT_MIB(tcp_stats.tcpActiveOpens, 1);
|
---|
675 | syscall(set_flg(cep->est_flgid, TCP_CEP_EVT_ESTABLISHED));
|
---|
676 |
|
---|
677 | #ifdef TCP_CFG_NON_BLOCKING
|
---|
678 |
|
---|
679 | if (cep->snd_nblk_tfn == TFN_TCP_CON_CEP) {
|
---|
680 |
|
---|
681 | /* ç¸æã®ã¢ãã¬ã¹ãã³ãã¼ããã*/
|
---|
682 | *cep->p_dstaddr = cep->dstaddr;
|
---|
683 |
|
---|
684 | if (IS_PTR_DEFINED(cep->callback)) {
|
---|
685 |
|
---|
686 | #ifdef TCP_CFG_NON_BLOCKING_COMPAT14
|
---|
687 |
|
---|
688 | NET_COUNT_TCP(net_count_tcp[NC_TCP_CONNECTS], 1);
|
---|
689 | (*cep->callback)(GET_TCP_CEPID(cep), cep->snd_nblk_tfn, E_OK);
|
---|
690 |
|
---|
691 | #else /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
692 |
|
---|
693 | ER error = E_OK;
|
---|
694 |
|
---|
695 | NET_COUNT_TCP(net_count_tcp[NC_TCP_CONNECTS], 1);
|
---|
696 | (*cep->callback)(GET_TCP_CEPID(cep), cep->snd_nblk_tfn, (void*)&error);
|
---|
697 |
|
---|
698 | #endif /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
699 |
|
---|
700 | }
|
---|
701 | else {
|
---|
702 | syslog(LOG_WARNING, "[TCP] no call back, CEP: %d.", GET_TCP_CEPID(cep));
|
---|
703 | error = RET_RST_DROP;
|
---|
704 | }
|
---|
705 | cep->p_dstaddr = NULL;
|
---|
706 | cep->snd_tskid = TA_NULL;
|
---|
707 | cep->snd_tfn = cep->snd_nblk_tfn = TFN_TCP_UNDEF;
|
---|
708 | }
|
---|
709 | else
|
---|
710 |
|
---|
711 | #endif /* of #ifdef TCP_CFG_NON_BLOCKING */
|
---|
712 |
|
---|
713 | NET_COUNT_TCP(net_count_tcp[NC_TCP_CONNECTS], 1);
|
---|
714 | }
|
---|
715 | }
|
---|
716 | else {
|
---|
717 | /* ACK ãã©ã°ããªãã¨ãã¯ãACK ãéã£ã¦ãCEP ã®ç¶æ
|
---|
718 | ã SYN åä¿¡æ¸ã¿ã«ããã*/
|
---|
719 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
720 | cep->timer[TCP_TIM_REXMT] = 0;
|
---|
721 | cep->fsm_state = TCP_FSM_SYN_RECVD;
|
---|
722 | }
|
---|
723 |
|
---|
724 | return error;
|
---|
725 | }
|
---|
726 |
|
---|
727 | /*
|
---|
728 | * trim_length -- åä¿¡ãã SDU é·ã調æ´ããã
|
---|
729 | */
|
---|
730 |
|
---|
731 | static void
|
---|
732 | trim_length (T_TCP_HDR *tcph, T_TCP_CEP *cep)
|
---|
733 | {
|
---|
734 | tcph->seq ++;
|
---|
735 | if (tcph->sum > cep->rcv_wnd) { /* 注æ: tcph->sum 㯠SDU é· */
|
---|
736 | /*
|
---|
737 | * SDU é·ãåä¿¡ã¦ã£ã³ããµã¤ãºãã大ããã¨ãã¯ãåä¿¡ã¦ã£ã³ããµã¤ãºä»¥éã¯
|
---|
738 | * ç ´æ£ããFIN ã«å¿çããªããã¨ã§ãç ´æ£ãããã¼ã¿ãåéãããã
|
---|
739 | */
|
---|
740 | tcph->sum = (uint16_t)cep->rcv_wnd;
|
---|
741 | tcph->flags &= ~TCP_FLG_FIN;
|
---|
742 | }
|
---|
743 | cep->snd_wl1 = tcph->seq - 1; /* cep->snd_wl1: ã¦ã£ã³ãæ´æ° SEQ çªå· */
|
---|
744 |
|
---|
745 | #ifdef TCP_CFG_EXTENTIONS
|
---|
746 | cep->rcv_up = tcph->seq; /* cep->rcv_up : åä¿¡ããç·æ¥ãã¤ã³ã¿ */
|
---|
747 | #endif
|
---|
748 | }
|
---|
749 |
|
---|
750 | /*
|
---|
751 | * proc_ack2 -- ACK ã®å¦ç (2)
|
---|
752 | *
|
---|
753 | * æ»ãå¤
|
---|
754 | *
|
---|
755 | * RET_OK æ£å¸¸
|
---|
756 | * RET_RETURN æ£å¸¸ããªã¿ã¼ã³ããã
|
---|
757 | * RET_DROP ã¨ã©ã¼ãã»ã°ã¡ã³ããç ´æ£ããã
|
---|
758 | * RET_RST_DROP ã¨ã©ã¼ãRST ãéä¿¡ããã»ã°ã¡ã³ããç ´æ£ããã
|
---|
759 | */
|
---|
760 |
|
---|
761 | static ER
|
---|
762 | proc_ack2 (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, bool_t *needoutput)
|
---|
763 | {
|
---|
764 | T_TCP_HDR *tcph;
|
---|
765 | ER ret = RET_OK;
|
---|
766 | uint32_t acked;
|
---|
767 | bool_t ourfinisacked = false;
|
---|
768 |
|
---|
769 | tcph = GET_TCP_HDR(input, thoff);
|
---|
770 |
|
---|
771 | /*
|
---|
772 | * ç¸æã«å信確èªããã ACK ãããã¾ã 確èªããã¦ããªã
|
---|
773 | * æå°éä¿¡ SEQ (snd_una) ãå¼ãã¨ãéä¿¡ã¦ã£ã³ããããã¡ãã
|
---|
774 | * åé¤ãã¦ãããªã¯ãããæ° (acked) ã«ãªãã
|
---|
775 | */
|
---|
776 | acked = tcph->ack - cep->snd_una;
|
---|
777 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_ACKS], 1);
|
---|
778 |
|
---|
779 | /*
|
---|
780 | * å¾å¾©æéè¨æ¸¬ (rtt) ãè¨å®ããã¦ãã¦ãè¨æ¸¬éå§ SEQ ãã
|
---|
781 | * å¾ã® ACK ãåä¿¡ããããã¿ã¤ãããã¯ãªãããã£ã³ã»ã«ãã
|
---|
782 | * åéã¿ã¤ããåè¨å®ããã
|
---|
783 | */
|
---|
784 | if (cep->rtt && SEQ_GT(tcph->ack, cep->rtseq)) {
|
---|
785 | set_rexmt_timer(cep, cep->rtt);
|
---|
786 | }
|
---|
787 |
|
---|
788 | /*
|
---|
789 | * å
|
---|
790 | ¨ã¦ã®æªç¢ºèªãã¼ã¿ã ACK ãããããåéã¿ã¤ããåæ¢ãã
|
---|
791 | * åéãè¨æ¶ãã (ããã«åºåãæç¶)ã
|
---|
792 | * ãããACK ãã¹ããããã«å¤ãã®ãã¼ã¿ããããªããåéã¿ã¤ãã«
|
---|
793 | * ç¾å¨ã®åéã¿ã¤ã ã¢ã¦ããè¨å®ããã
|
---|
794 | */
|
---|
795 | if (tcph->ack == cep->snd_max) { /* cep->snd_max: éä¿¡ããæ大 SEQ */
|
---|
796 |
|
---|
797 | #ifdef TCP_CFG_SWBUF_CSAVE
|
---|
798 |
|
---|
799 | /*
|
---|
800 | * éä¿¡ã¦ã£ã³ããããã¡ã®çã³ãã¼æ©è½ãæå¹ã®å ´åã¯ã
|
---|
801 | * éä¿¡æ¸ã¿ã§ãACKãå®äºããã¾ã§åéã¿ã¤ããå¤æ´ããªãã
|
---|
802 | */
|
---|
803 | if ((cep->flags & TCP_CEP_FLG_WBCS_MASK) == TCP_CEP_FLG_WBCS_ACKED)
|
---|
804 | cep->timer[TCP_TIM_REXMT] = 0;
|
---|
805 |
|
---|
806 | #else /* of #ifdef TCP_CFG_SWBUF_CSAVE */
|
---|
807 |
|
---|
808 | cep->timer[TCP_TIM_REXMT] = 0;
|
---|
809 |
|
---|
810 | #endif /* of #ifdef TCP_CFG_SWBUF_CSAVE */
|
---|
811 |
|
---|
812 | *needoutput = true;
|
---|
813 | }
|
---|
814 | else if (cep->timer[TCP_TIM_PERSIST] == 0) {
|
---|
815 | cep->timer[TCP_TIM_REXMT] = cep->rxtcur; /* cep->rxtcur: ç¾å¨ã®åéã¿ã¤ã ã¢ã¦ã */
|
---|
816 | }
|
---|
817 |
|
---|
818 | /* ç¸æãå信確èªãããã¼ã¿ãããã¨ãã®å¦ç */
|
---|
819 | if (acked) {
|
---|
820 | uint32_t cw = cep->snd_cwnd; /* cep->snd_cwnd: 輻輳ã¦ã£ã³ããµã¤ãº */
|
---|
821 | uint32_t incr = cep->maxseg; /* cep->maxseg: æ大ã»ã°ã¡ã³ããµã¤ãº */
|
---|
822 |
|
---|
823 | /*
|
---|
824 | * æ°ãã«ç¸æãå信確èªãããã¼ã¿ããã£ãã¨ãã¯ã
|
---|
825 | * 輻輳ã¦ã£ã³ããµã¤ãºã大ããããã
|
---|
826 | * 輻輳ã¦ã£ã³ããµã¤ãº (snd_cwnd) ã
|
---|
827 | * 輻輳ã¦ã£ã³ããµã¤ãºã®ãããå¤ (snd_ssthresh) ãã大ããã¨ãã¯
|
---|
828 | * 輻輳åé¿å¶å¾¡ãè¡ãã
|
---|
829 | *
|
---|
830 | * snd_cwnd = snd_cwnd + maxseg * maxseg / snd_cwnd;
|
---|
831 | *
|
---|
832 | * çãããå°ããã¨ãã¯ãã¹ãã¼ã¹ã¿ã¼ãå¶å¾¡ãè¡ãã
|
---|
833 | *
|
---|
834 | * snd_cwnd = snd_cwnd + maxseg
|
---|
835 | *
|
---|
836 | */
|
---|
837 | if (cw > cep->snd_ssthresh)
|
---|
838 | /* 輻輳åé¿å¶å¾¡ */
|
---|
839 | incr = incr * incr / cw;
|
---|
840 |
|
---|
841 | if (cw + incr < MAX_TCP_WIN_SIZE)
|
---|
842 | cep->snd_cwnd = (uint16_t)(cw + incr);
|
---|
843 | else
|
---|
844 | cep->snd_cwnd = MAX_TCP_WIN_SIZE;
|
---|
845 |
|
---|
846 | /*
|
---|
847 | * éä¿¡ã¦ã£ã³ããããã¡ãããç¸æãå信確èªãããã¼ã¿æ° (acked) ã®ãã¼ã¿ãåé¤ããã
|
---|
848 | */
|
---|
849 | if (acked > cep->swbuf_count) {
|
---|
850 | cep->snd_wnd -= cep->swbuf_count;
|
---|
851 | TCP_DROP_SWBUF(cep, (uint_t)cep->swbuf_count);
|
---|
852 | ourfinisacked = true;
|
---|
853 | }
|
---|
854 | else {
|
---|
855 | cep->snd_wnd -= (uint16_t)acked;
|
---|
856 | TCP_DROP_SWBUF(cep, (uint_t)acked);
|
---|
857 | ourfinisacked = false;
|
---|
858 | }
|
---|
859 |
|
---|
860 | /* éä¿¡ã¦ã£ã³ããããã¡ã«ç©ºããã§ãããã¨ãç¥ãããã*/
|
---|
861 | syscall(set_flg(cep->snd_flgid, TCP_CEP_EVT_SWBUF_READY));
|
---|
862 |
|
---|
863 | /*
|
---|
864 | * éé確èªããã¦ããªãæå°éä¿¡ SEQ (snd_una) ã
|
---|
865 | * ä»åéé確èªããã ACK ã¾ã§é²ãã
|
---|
866 | * 次ã®éä¿¡ãã¼ã¿ã® SEQ (snd_nxt) ããæ°ãã
|
---|
867 | * éé確èªããã¦ããªãæå°éä¿¡ SEQ (snd_una)
|
---|
868 | * ã¾ã§é²ããã
|
---|
869 | */
|
---|
870 | cep->snd_una += acked;
|
---|
871 | if (SEQ_LT(cep->snd_nxt, cep->snd_una))
|
---|
872 | cep->snd_nxt = cep->snd_una;
|
---|
873 |
|
---|
874 | /*
|
---|
875 | * ç¶æ
|
---|
876 | ã«ããåå²
|
---|
877 | */
|
---|
878 | switch (cep->fsm_state) {
|
---|
879 | case TCP_FSM_FIN_WAIT_1: /* APP ãçµäºãFIN éä¿¡æ¸ã¿ãACK å¾
|
---|
880 | ã¡ */
|
---|
881 | if (ourfinisacked) {
|
---|
882 | cep->fsm_state = TCP_FSM_FIN_WAIT_2;
|
---|
883 | cep->timer[TCP_TIM_2MSL] = TCP_TVAL_KEEP_COUNT * TCP_TVAL_KEEP_INTERVAL;
|
---|
884 | }
|
---|
885 | break;
|
---|
886 | case TCP_FSM_CLOSING: /* åæã¯ãã¼ãºãFIN 交ææ¸ã¿ãACK å¾
|
---|
887 | ã¡ */
|
---|
888 | if (ourfinisacked) {
|
---|
889 | /*
|
---|
890 | * éä¿¡ãã FIN ã確èªããã¦ããã°ç¶æ
|
---|
891 | ãå¤æ´ãã
|
---|
892 | * ãã¹ã¦ã®ã¿ã¤ãããªã»ããããå¾ã2MSL ã¿ã¤ããè¨å®ããã
|
---|
893 | */
|
---|
894 | cep->fsm_state = TCP_FSM_TIME_WAIT;
|
---|
895 | tcp_cancel_timers(cep);
|
---|
896 | cep->timer[TCP_TIM_2MSL] = 2 * TCP_TVAL_MSL;
|
---|
897 | }
|
---|
898 | break;
|
---|
899 | case TCP_FSM_LAST_ACK: /* APP ãçµäºãACK å¾
|
---|
900 | ã¡ */
|
---|
901 | if (ourfinisacked) {
|
---|
902 | /*
|
---|
903 | * éä¿¡ãã FIN ã確èªããã¦ããã°ãcep ãã¯ãã¼ãºãã
|
---|
904 | * ã»ã°ã¡ã³ããç ´æ£ããã
|
---|
905 | */
|
---|
906 | cep = tcp_close(cep);
|
---|
907 | ret = RET_DROP;
|
---|
908 | }
|
---|
909 | break;
|
---|
910 | case TCP_FSM_TIME_WAIT: /* ç¸æããã® FIN åä¿¡æ¸ã¿ãæéå¾
|
---|
911 | ã¡ */
|
---|
912 | /*
|
---|
913 | * ç¸æãã FIN ãåéããããããä¸åº¦2MSL ã¿ã¤ããè¨å®ãã
|
---|
914 | * ACK éä¿¡å¾ãã»ã°ã¡ã³ããç ´æ£ããã
|
---|
915 | */
|
---|
916 | cep->timer[TCP_TIM_2MSL] = 2 * TCP_TVAL_MSL;
|
---|
917 | return drop_after_ack(input, cep, thoff);
|
---|
918 | }
|
---|
919 | }
|
---|
920 |
|
---|
921 | return ret;
|
---|
922 | }
|
---|
923 |
|
---|
924 | /*
|
---|
925 | * proc_ack1 -- ACK ã®å¦ç (1)
|
---|
926 | *
|
---|
927 | * æ»ãå¤:
|
---|
928 | * RET_OK æ£å¸¸
|
---|
929 | * RET_RETURN æ£å¸¸ããªã¿ã¼ã³ããã
|
---|
930 | * RET_DROP ã¨ã©ã¼ãã»ã°ã¡ã³ããç ´æ£ããã
|
---|
931 | * RET_RST_DROP ã¨ã©ã¼ãRST ãéä¿¡ããã»ã°ã¡ã³ããç ´æ£ããã
|
---|
932 | *
|
---|
933 | */
|
---|
934 |
|
---|
935 | static ER
|
---|
936 | proc_ack1 (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff, bool_t *needoutput)
|
---|
937 | {
|
---|
938 | T_TCP_HDR *tcph = GET_TCP_HDR(input, thoff);
|
---|
939 |
|
---|
940 | switch (cep->fsm_state) {
|
---|
941 | case TCP_FSM_SYN_RECVD: /* SYN ãåä¿¡ããSYN éä¿¡æ¸ã¿ */
|
---|
942 |
|
---|
943 | /* ç¶æ
|
---|
944 | ãå¤æ´ããã*/
|
---|
945 | if (cep->flags & TCP_CEP_FLG_NEED_FIN) {
|
---|
946 | cep->fsm_state = TCP_FSM_FIN_WAIT_1;
|
---|
947 | cep->flags &= ~TCP_CEP_FLG_NEED_FIN;
|
---|
948 | }
|
---|
949 | else {
|
---|
950 | cep->timer[TCP_TIM_KEEP] = TCP_TVAL_KEEP_IDLE;
|
---|
951 | cep->fsm_state = TCP_FSM_ESTABLISHED;
|
---|
952 |
|
---|
953 | /* TCP é信端ç¹ããTCP åä»å£ã解æ¾ããã*/
|
---|
954 | cep->rep = NULL;
|
---|
955 |
|
---|
956 | syscall(set_flg(cep->est_flgid, TCP_CEP_EVT_ESTABLISHED));
|
---|
957 |
|
---|
958 | #ifdef TCP_CFG_NON_BLOCKING
|
---|
959 |
|
---|
960 | if (cep->rcv_nblk_tfn == TFN_TCP_ACP_CEP) {
|
---|
961 |
|
---|
962 | /* ç¸æã®ã¢ãã¬ã¹ãã³ãã¼ããã*/
|
---|
963 | *cep->p_dstaddr = cep->dstaddr;
|
---|
964 |
|
---|
965 | if (IS_PTR_DEFINED(cep->callback)) {
|
---|
966 |
|
---|
967 | #ifdef TCP_CFG_NON_BLOCKING_COMPAT14
|
---|
968 |
|
---|
969 | NET_COUNT_MIB(tcp_stats.tcpPassiveOpens, 1);
|
---|
970 | NET_COUNT_TCP(net_count_tcp[NC_TCP_ACCEPTS], 1);
|
---|
971 | (*cep->callback)(GET_TCP_CEPID(cep), cep->rcv_nblk_tfn, E_OK);
|
---|
972 |
|
---|
973 | #else /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
974 |
|
---|
975 | ER error = E_OK;
|
---|
976 |
|
---|
977 | NET_COUNT_MIB(tcp_stats.tcpPassiveOpens, 1);
|
---|
978 | NET_COUNT_TCP(net_count_tcp[NC_TCP_ACCEPTS], 1);
|
---|
979 | (*cep->callback)(GET_TCP_CEPID(cep), cep->rcv_nblk_tfn, (void*)&error);
|
---|
980 |
|
---|
981 | #endif /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
982 |
|
---|
983 | cep->p_dstaddr = NULL;
|
---|
984 | cep->rcv_tskid = TA_NULL;
|
---|
985 | cep->rcv_tfn = cep->rcv_nblk_tfn = TFN_TCP_UNDEF;
|
---|
986 | }
|
---|
987 | else {
|
---|
988 | syslog(LOG_WARNING, "[TCP] no call back, CEP: %d.", GET_TCP_CEPID(cep));
|
---|
989 | cep->p_dstaddr = NULL;
|
---|
990 | cep->rcv_tskid = TA_NULL;
|
---|
991 | cep->rcv_tfn = cep->rcv_nblk_tfn = TFN_TCP_UNDEF;
|
---|
992 | return RET_RST_DROP;
|
---|
993 | }
|
---|
994 | }
|
---|
995 |
|
---|
996 | if (cep->snd_nblk_tfn == TFN_TCP_CON_CEP) {
|
---|
997 |
|
---|
998 | /* ç¸æã®ã¢ãã¬ã¹ãã³ãã¼ããã*/
|
---|
999 | *cep->p_dstaddr = cep->dstaddr;
|
---|
1000 |
|
---|
1001 | if (IS_PTR_DEFINED(cep->callback)) {
|
---|
1002 |
|
---|
1003 | #ifdef TCP_CFG_NON_BLOCKING_COMPAT14
|
---|
1004 |
|
---|
1005 | NET_COUNT_MIB(tcp_stats.tcpActiveOpens, 1);
|
---|
1006 | NET_COUNT_TCP(net_count_tcp[NC_TCP_CONNECTS], 1);
|
---|
1007 | (*cep->callback)(GET_TCP_CEPID(cep), cep->snd_nblk_tfn, E_OK);
|
---|
1008 |
|
---|
1009 | #else /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
1010 |
|
---|
1011 | ER error = E_OK;
|
---|
1012 |
|
---|
1013 | NET_COUNT_MIB(tcp_stats.tcpActiveOpens, 1);
|
---|
1014 | NET_COUNT_TCP(net_count_tcp[NC_TCP_CONNECTS], 1);
|
---|
1015 | (*cep->callback)(GET_TCP_CEPID(cep), cep->snd_nblk_tfn, (void*)&error);
|
---|
1016 |
|
---|
1017 | #endif /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
1018 |
|
---|
1019 | cep->p_dstaddr = NULL;
|
---|
1020 | cep->snd_tskid = TA_NULL;
|
---|
1021 | cep->snd_tfn = cep->snd_nblk_tfn = TFN_TCP_UNDEF;
|
---|
1022 | }
|
---|
1023 | else {
|
---|
1024 | syslog(LOG_WARNING, "[TCP] no call back, CEP: %d.", GET_TCP_CEPID(cep));
|
---|
1025 | cep->p_dstaddr = NULL;
|
---|
1026 | cep->snd_tskid = TA_NULL;
|
---|
1027 | cep->snd_tfn = cep->snd_nblk_tfn = TFN_TCP_UNDEF;
|
---|
1028 | return RET_RST_DROP;
|
---|
1029 | }
|
---|
1030 | }
|
---|
1031 |
|
---|
1032 | #endif /* of #ifdef TCP_CFG_NON_BLOCKING */
|
---|
1033 |
|
---|
1034 | if (cep->rcv_tfn == TFN_TCP_ACP_CEP) {
|
---|
1035 | NET_COUNT_MIB(tcp_stats.tcpPassiveOpens, 1);
|
---|
1036 | NET_COUNT_TCP(net_count_tcp[NC_TCP_ACCEPTS], 1);
|
---|
1037 | }
|
---|
1038 |
|
---|
1039 | if (cep->snd_tfn == TFN_TCP_CON_CEP) {
|
---|
1040 | NET_COUNT_MIB(tcp_stats.tcpActiveOpens, 1);
|
---|
1041 | NET_COUNT_TCP(net_count_tcp[NC_TCP_CONNECTS], 1);
|
---|
1042 | }
|
---|
1043 | }
|
---|
1044 |
|
---|
1045 | /*
|
---|
1046 | * SDU ããªã FIN ãã¤ãã¦ããªããã°ãtcp_move_ra2rw() ãå¼åºãã
|
---|
1047 | */
|
---|
1048 | if (tcph->sum == 0 && (tcph->flags & TCP_FLG_FIN) == 0) /* tcph->sum 㯠SDU é· */
|
---|
1049 | tcph->flags = tcp_move_ra2rw(cep, tcph->flags);
|
---|
1050 |
|
---|
1051 | cep->snd_wl1 = tcph->seq - 1; /* snd_wl1: ã¦ã£ã³ãæ´æ° SEQ */
|
---|
1052 |
|
---|
1053 | /* break; ä¸ã«è½ã¡ãã*/
|
---|
1054 |
|
---|
1055 | case TCP_FSM_ESTABLISHED: /* ã³ãã¯ã·ã§ã³éè¨å®äº */
|
---|
1056 | case TCP_FSM_FIN_WAIT_1: /* çµäºãã¦ãFIN éä¿¡æ¸ã¿ */
|
---|
1057 | case TCP_FSM_FIN_WAIT_2: /* çµäºãFIN ä¼é確èªåä¿¡ãFINå¾
|
---|
1058 | ã¡*/
|
---|
1059 | case TCP_FSM_CLOSE_WAIT: /* FIN åä¿¡ãã¯ãã¼ãºå¾
|
---|
1060 | ã¡ */
|
---|
1061 | case TCP_FSM_CLOSING: /* çµäºãFIN 交ææ¸ã¿ãACK å¾
|
---|
1062 | ã¡ */
|
---|
1063 | case TCP_FSM_LAST_ACK: /* FIN åä¿¡ãçµäºãACK å¾
|
---|
1064 | ã¡ */
|
---|
1065 | case TCP_FSM_TIME_WAIT: /* çµäºãæéå¾
|
---|
1066 | ã¡ */
|
---|
1067 |
|
---|
1068 | if (SEQ_LE(tcph->ack, cep->snd_una)) {
|
---|
1069 |
|
---|
1070 | /*
|
---|
1071 | * åä¿¡ç¢ºèª ACK ã æªç¢ºèªã®æå°éä¿¡ SEQ (snd_una) ã¨åãã以åã®ã¨ãã®å¦ç
|
---|
1072 | * ã¤ã¾ããå¤éã« ACK ãåä¿¡ãããã¨ãæå³ãã¦ããã
|
---|
1073 | */
|
---|
1074 |
|
---|
1075 | if (tcph->sum == 0 && tcph->win == cep->snd_wnd) { /* tcph->sum 㯠SDU é· */
|
---|
1076 |
|
---|
1077 | /*
|
---|
1078 | * SDU ããªããç¸æã®ã¦ã£ã³ããµã¤ãºãå¤æ´ããã¦ããªããã°ã
|
---|
1079 | * ãã§ã«éä¿¡ããã»ã°ã¡ã³ãã®ä¸ã§ãACK (tcph->ack) ã¨
|
---|
1080 | * åã SEQ ããå§ã¾ãã»ã°ã¡ã³ãããéä¸ã§æ¶å¤±ããå¯è½æ§ãããã
|
---|
1081 | * ãã®å ´åã¯ãé«éå転éã¨é«éãªã«ããªãè¡ãã
|
---|
1082 | */
|
---|
1083 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_DUP_ACKS], 1);
|
---|
1084 |
|
---|
1085 | if (cep->timer[TCP_TIM_REXMT] == 0 || tcph->ack != cep->snd_una) {
|
---|
1086 |
|
---|
1087 | /*
|
---|
1088 | * åéã¿ã¤ããã»ããããã¦ããªãã¨ãã
|
---|
1089 | * ã¾ãã¯ãACK (tcph->ack) ã¨æªç¢ºèªã®æå°éä¿¡ SEQã
|
---|
1090 | * ä¸è´ããªãã¨ãã¯ãå¤é ACK æ°ã 0 ã«ããã
|
---|
1091 | */
|
---|
1092 | cep->dupacks = 0;
|
---|
1093 | }
|
---|
1094 |
|
---|
1095 | else if (++ cep->dupacks == MAX_TCP_REXMT_THRESH) {
|
---|
1096 |
|
---|
1097 | /*
|
---|
1098 | * å¤é ACK æ°ããããå¤ (æ¨æº 3) ã«ãªã£ãã
|
---|
1099 | * é«éå転éå¦çãéå§ããã
|
---|
1100 | */
|
---|
1101 | uint_t win;
|
---|
1102 |
|
---|
1103 | /*
|
---|
1104 | * 輻輳ã¦ã£ã³ããµã¤ãº(snd_cwnd)ã®ãããå¤ãè¨å®ããã
|
---|
1105 | *
|
---|
1106 | * ç¸æã®åä¿¡å¯è½ã¦ã£ã³ããµã¤ãº (snd_wnd) ã
|
---|
1107 | * 輻輳ã¦ã£ã³ããµã¤ãº (snd_cwnd) ã® 1/2ã
|
---|
1108 | * ãã ãã2 * maxseg 以ä¸ã
|
---|
1109 | *
|
---|
1110 | */
|
---|
1111 | if (cep->snd_wnd < cep->snd_cwnd)
|
---|
1112 | win = cep->snd_wnd / 2 / cep->maxseg;
|
---|
1113 | else
|
---|
1114 | win = cep->snd_cwnd / 2 / cep->maxseg;
|
---|
1115 | if (win < 2)
|
---|
1116 | win = 2;
|
---|
1117 | cep->snd_ssthresh = win * cep->maxseg;
|
---|
1118 |
|
---|
1119 | /* åéã¿ã¤ãã¨å¾å¾©æéããªã»ããããã*/
|
---|
1120 | cep->timer[TCP_TIM_REXMT] = 0;
|
---|
1121 | cep->rtt = 0;
|
---|
1122 |
|
---|
1123 | /* æ¶å¤±ããã»ã°ã¡ã³ããéä¿¡ããã*/
|
---|
1124 | cep->snd_old_nxt = cep->snd_nxt;
|
---|
1125 | cep->snd_nxt = tcph->ack;
|
---|
1126 | cep->snd_cwnd = cep->maxseg;
|
---|
1127 |
|
---|
1128 | /*
|
---|
1129 | * snd_nxt ãå
|
---|
1130 | ã«æ»ãããã«è¨å®ãã¦
|
---|
1131 | * éä¿¡ãæ示ããã
|
---|
1132 | */
|
---|
1133 | cep->flags |= TCP_CEP_FLG_POST_OUTPUT |
|
---|
1134 | TCP_CEP_FLG_FORCE |
|
---|
1135 | TCP_CEP_FLG_FORCE_CLEAR |
|
---|
1136 | TCP_CEP_FLG_RESTORE_NEXT_OUTPUT;
|
---|
1137 | sig_sem(SEM_TCP_POST_OUTPUT);
|
---|
1138 |
|
---|
1139 | /* 輻輳ã¦ã£ã³ããµã¤ãºãæ´æ°ããã*/
|
---|
1140 | cep->snd_cwnd = (uint16_t)(cep->snd_ssthresh
|
---|
1141 | + cep->maxseg * cep->dupacks);
|
---|
1142 |
|
---|
1143 | return RET_DROP;
|
---|
1144 | }
|
---|
1145 |
|
---|
1146 | else if (cep->dupacks > MAX_TCP_REXMT_THRESH) {
|
---|
1147 |
|
---|
1148 | /*
|
---|
1149 | * å¤é ACK æ°ããããå¤ (æ¨æº 3) ãè¶
|
---|
1150 | ããã
|
---|
1151 | * 輻輳ã¦ã£ã³ããµã¤ãºãå¢å ããªããåéããã
|
---|
1152 | */
|
---|
1153 | cep->snd_cwnd += cep->maxseg;
|
---|
1154 |
|
---|
1155 | /* éä¿¡ãæ示ããã*/
|
---|
1156 | cep->flags |= TCP_CEP_FLG_POST_OUTPUT;
|
---|
1157 | sig_sem(SEM_TCP_POST_OUTPUT);
|
---|
1158 |
|
---|
1159 | return RET_DROP;
|
---|
1160 | }
|
---|
1161 | }
|
---|
1162 | else
|
---|
1163 | cep->dupacks = 0;
|
---|
1164 | break;
|
---|
1165 | }
|
---|
1166 |
|
---|
1167 | /*
|
---|
1168 | * åä¿¡ç¢ºèª ACK ã æªç¢ºèªã®æå°éä¿¡ SEQ (snd_una) 以éã®ã¨ãã®å¦ç
|
---|
1169 | */
|
---|
1170 | if (cep->dupacks >= MAX_TCP_REXMT_THRESH && cep->snd_cwnd > cep->snd_ssthresh)
|
---|
1171 | /*
|
---|
1172 | * é«éå転éãè¡ã£ã¦ããã¨ãã¯ã輻輳ã¦ã£ã³ããµã¤ãºããããå¤ã¾ã§æ»ãã
|
---|
1173 | */
|
---|
1174 | cep->snd_cwnd = (uint16_t)cep->snd_ssthresh;
|
---|
1175 |
|
---|
1176 | cep->dupacks = 0;
|
---|
1177 |
|
---|
1178 | if (SEQ_GT(tcph->ack, cep->snd_max))
|
---|
1179 | /*
|
---|
1180 | * åä¿¡ãã ACK ãéä¿¡ããæ大 SEQ ãè¶
|
---|
1181 | ãã¦ããã¨ãã®å¦ç
|
---|
1182 | */
|
---|
1183 | return drop_after_ack(input, cep, thoff);
|
---|
1184 |
|
---|
1185 | if (cep->flags & TCP_CEP_FLG_NEED_SYN) {
|
---|
1186 | /*
|
---|
1187 | * SYN éä¿¡è¦æ±ãåãæ¶ãã¦ãæªç¢ºèªã®æå°éä¿¡ SEQ ãé²ããã
|
---|
1188 | */
|
---|
1189 | cep->flags &= ~TCP_CEP_FLG_NEED_SYN;
|
---|
1190 | cep->snd_una ++;
|
---|
1191 | }
|
---|
1192 |
|
---|
1193 | return proc_ack2(input, cep, thoff, needoutput);
|
---|
1194 | break;
|
---|
1195 | }
|
---|
1196 | return RET_OK;
|
---|
1197 | }
|
---|
1198 |
|
---|
1199 | /*
|
---|
1200 | * update_wnd -- ã¦ã£ã³ããµã¤ãºãæ´æ°ããã
|
---|
1201 | *
|
---|
1202 | * æ»ãå¤: éä¿¡ãå¿
|
---|
1203 | è¦ãªã true ãè¿ãã
|
---|
1204 | */
|
---|
1205 |
|
---|
1206 | static bool_t
|
---|
1207 | update_wnd (T_TCP_HDR *tcph, T_TCP_CEP *cep)
|
---|
1208 | {
|
---|
1209 |
|
---|
1210 | /*
|
---|
1211 | * æ´æ°æ¡ä»¶
|
---|
1212 | *
|
---|
1213 | * ACK ãã©ã°ãã»ããããã¦ãã &&
|
---|
1214 | * (ååã¦ã£ã³ããæ´æ°ãã SEQ (snd_wl1) ã SEQ ããå ||
|
---|
1215 | * ååã¦ã£ã³ããæ´æ°ãã SEQ (snd_wl1) ã SEQ ã¨åã &&
|
---|
1216 | * (ååã¦ã£ã³ããæ´æ°ãã ACK (snd_wl2) ã ACK ããå ||
|
---|
1217 | * (ååã¦ã£ã³ããæ´æ°ãã ACK (snd_wl2) ã ACK ã¨åã &&
|
---|
1218 | * WIN ãç¸æã®åä¿¡å¯è½ã¦ã£ã³ããµã¤ãº (snd_wnd) ãã大ãã
|
---|
1219 | * )
|
---|
1220 | * )
|
---|
1221 | * )
|
---|
1222 | */
|
---|
1223 | if ((tcph->flags & TCP_FLG_ACK) &&
|
---|
1224 | (SEQ_LT(cep->snd_wl1, tcph->seq) ||
|
---|
1225 | (cep->snd_wl1 == tcph->seq &&
|
---|
1226 | (SEQ_LT(cep->snd_wl2, tcph->ack) ||
|
---|
1227 | (cep->snd_wl2 == tcph->ack && tcph->win > cep->snd_wnd))))) {
|
---|
1228 |
|
---|
1229 | cep->snd_wnd = tcph->win;
|
---|
1230 | cep->snd_wl1 = tcph->seq;
|
---|
1231 | cep->snd_wl2 = tcph->ack;
|
---|
1232 |
|
---|
1233 | if (cep->snd_wnd > cep->max_sndwnd)
|
---|
1234 | /* ä»ã¾ã§ã®æ大éä¿¡ã¦ã£ã³ããµã¤ãºãæ´æ°ããã*/
|
---|
1235 | cep->max_sndwnd = cep->snd_wnd;
|
---|
1236 |
|
---|
1237 | #ifdef TCP_CFG_SWBUF_CSAVE
|
---|
1238 |
|
---|
1239 | if ((cep->flags & TCP_CEP_FLG_WBCS_MASK) == TCP_CEP_FLG_WBCS_WOPEN_PEND) {
|
---|
1240 |
|
---|
1241 | /*
|
---|
1242 | * éä¿¡ã¦ã£ã³ããããã¡ç¨ã®ãããã¯ã¼ã¯ãããã¡å²ãå½ã¦ä¸ã§ã
|
---|
1243 | * ç¸æã®åä¿¡ã¦ã£ã³ãã空ãã®ãå¾
|
---|
1244 | ã£ã¦ããã¨ãã®å¦ç
|
---|
1245 | */
|
---|
1246 | if (cep->snd_wnd > 0) {
|
---|
1247 |
|
---|
1248 | /*
|
---|
1249 | * ç¸æã®åä¿¡ã¦ã£ã³ãã空ããã¨ãã¯ã
|
---|
1250 | * éä¿¡ã¦ã£ã³ããããã¡ç¨ã®ãããã¯ã¼ã¯ãããã¡å²ãå½ã¦ãåéããã
|
---|
1251 | */
|
---|
1252 | cep->flags = (cep->flags & ~TCP_CEP_FLG_WBCS_MASK)
|
---|
1253 | | TCP_CEP_FLG_WBCS_FREE | TCP_CEP_FLG_POST_OUTPUT;
|
---|
1254 | sig_sem(SEM_TCP_POST_OUTPUT);
|
---|
1255 | }
|
---|
1256 | }
|
---|
1257 |
|
---|
1258 | #endif /* of #ifdef TCP_CFG_SWBUF_CSAVE */
|
---|
1259 |
|
---|
1260 | return true;
|
---|
1261 | }
|
---|
1262 | else
|
---|
1263 | return false;
|
---|
1264 | }
|
---|
1265 |
|
---|
1266 | /*
|
---|
1267 | * proc_urg -- ç·æ¥ãã¼ã¿ã¤ãã®ã»ã°ã¡ã³ãã®å¦ç
|
---|
1268 | */
|
---|
1269 |
|
---|
1270 | #ifdef TCP_CFG_EXTENTIONS
|
---|
1271 |
|
---|
1272 | static void
|
---|
1273 | proc_urg (T_TCP_HDR *tcph, T_TCP_CEP *cep)
|
---|
1274 | {
|
---|
1275 | if ((tcph->flags & TCP_FLG_URG) && VALID_URG_POINTER(tcph->urp) &&
|
---|
1276 | TCP_FSM_HAVE_RCVD_FIN(cep->fsm_state) == 0) {
|
---|
1277 |
|
---|
1278 | /* ç·æ¥ãã¼ã¿ã¤ãã®ã»ã°ã¡ã³ãã®å¦ç */
|
---|
1279 |
|
---|
1280 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_URG_SEGS], 1);
|
---|
1281 | if (tcph->urp + cep->rwbuf_count > cep->rbufsz) {
|
---|
1282 |
|
---|
1283 | /*
|
---|
1284 | * ç·æ¥ãã¤ã³ã¿ã®ä½ç½®ãåä¿¡ã¦ã£ã³ããããã¡ã®
|
---|
1285 | * ç¯å²ãè¶
|
---|
1286 | ããã¨ãã¯ä½ãããªãã
|
---|
1287 | */
|
---|
1288 | tcph->urp = 0;
|
---|
1289 | tcph->flags &= ~TCP_FLG_URG;
|
---|
1290 | }
|
---|
1291 |
|
---|
1292 | if (SEQ_GT(tcph->seq + tcph->urp, cep->rcv_up))
|
---|
1293 | /* ç·æ¥ãã¤ã³ã¿ãæ´æ°ãããã¨ãã®å¦ç */
|
---|
1294 | cep->rcv_up = tcph->seq + tcph->urp;
|
---|
1295 |
|
---|
1296 | if ((tcph->flags & TCP_FLG_URG) && (tcph->urp + TCP_CFG_URG_OFFSET) < tcph->sum) { /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1297 |
|
---|
1298 | /*
|
---|
1299 | * ç·æ¥ãã¤ã³ã¿ã®ä½ç½®ããä»ååä¿¡ããã»ã°ã¡ã³ãå
|
---|
1300 | ã®å ´åã¯ã
|
---|
1301 | * ã³ã¼ã«ããã¯é¢æ°ãå¼ã³åºãã
|
---|
1302 | */
|
---|
1303 | cep->urg_tcph = tcph;
|
---|
1304 | if (IS_PTR_DEFINED(cep->callback)) {
|
---|
1305 |
|
---|
1306 | #ifdef TCP_CFG_NON_BLOCKING_COMPAT14
|
---|
1307 |
|
---|
1308 | (*cep->callback)(GET_TCP_CEPID(cep), TEV_TCP_RCV_OOB, (void*)(uint32_t)1);
|
---|
1309 |
|
---|
1310 | #else /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
1311 |
|
---|
1312 | uint32_t len = 1;
|
---|
1313 |
|
---|
1314 | (*cep->callback)(GET_TCP_CEPID(cep), TEV_TCP_RCV_OOB, (void*)&len);
|
---|
1315 |
|
---|
1316 | #endif /* of #ifdef TCP_CFG_NON_BLOCKING_COMPAT14 */
|
---|
1317 |
|
---|
1318 | }
|
---|
1319 | else {
|
---|
1320 | syslog(LOG_WARNING, "[TCP] no call back for OOB, CEP: %d.", GET_TCP_CEPID(cep));
|
---|
1321 | }
|
---|
1322 |
|
---|
1323 | if (cep->urg_tcph != NULL) {
|
---|
1324 | /* ã³ã¼ã«ããã¯é¢æ°å
|
---|
1325 | 㧠tcp_rcv_oob() ãå¼åºããªãã£ãã*/
|
---|
1326 | cep->urg_tcph = NULL;
|
---|
1327 | tcph->urp = 0;
|
---|
1328 | }
|
---|
1329 | else {
|
---|
1330 | /*
|
---|
1331 | * ã³ã¼ã«ããã¯é¢æ°å
|
---|
1332 | 㧠tcp_rcv_oob() ãå¼åºããæã¯ã
|
---|
1333 | * SDU é·ã®è£æ£å¤ãè¨å®ããã
|
---|
1334 | */
|
---|
1335 | tcph->urp = 1;
|
---|
1336 | }
|
---|
1337 | }
|
---|
1338 | else if (tcph->urp > 0) {
|
---|
1339 | tcph->urp = 0;
|
---|
1340 | }
|
---|
1341 |
|
---|
1342 | }
|
---|
1343 | else if (SEQ_GT(cep->rcv_nxt, cep->rcv_up)) {
|
---|
1344 | cep->rcv_up = cep->rcv_nxt;
|
---|
1345 | tcph->urp = 0;
|
---|
1346 | }
|
---|
1347 | }
|
---|
1348 |
|
---|
1349 | #else /* of #ifdef TCP_CFG_EXTENTIONS */
|
---|
1350 |
|
---|
1351 | static void
|
---|
1352 | proc_urg (T_TCP_HDR *tcph, T_TCP_CEP *cep)
|
---|
1353 | {
|
---|
1354 | tcph->urp = 0;
|
---|
1355 | }
|
---|
1356 |
|
---|
1357 | #endif /* of #ifdef TCP_CFG_EXTENTIONS */
|
---|
1358 |
|
---|
1359 | /*
|
---|
1360 | * drop_after_ack -- åä¿¡ã»ã°ã¡ã³ããç ´æ£ããå¾ãACK ãè¿ã (注æ: ååã¨ã¯åã£ã¦ããªã)ã
|
---|
1361 | *
|
---|
1362 | * æ»ãå¤:
|
---|
1363 | * RET_RETURN æ£å¸¸ããªã¿ã¼ã³ããã
|
---|
1364 | * RET_RST_DROP ã¨ã©ã¼ãRST ãéä¿¡ããã»ã°ã¡ã³ããç ´æ£ããã
|
---|
1365 | */
|
---|
1366 |
|
---|
1367 | static ER
|
---|
1368 | drop_after_ack (T_NET_BUF *input, T_TCP_CEP *cep, uint_t thoff)
|
---|
1369 | {
|
---|
1370 | T_TCP_HDR *tcph = GET_TCP_HDR(input, thoff);
|
---|
1371 |
|
---|
1372 | /*
|
---|
1373 | * SYN åä¿¡ç¶æ
|
---|
1374 | ã§ãACK ãéé確èªããã¦ããªãæå°éä¿¡ SEQ (snd_una) ãã
|
---|
1375 | * åã®å¤ããéä¿¡ãããæ大 SEQ (snd_max) ããå¾ã®å¤ã®å ´åã¯ãç¸æã« RST ã
|
---|
1376 | * éã£ã¦çµäºãããããã¯ã"LAND" DoS æ»æã¸ã®é²å¾¡ã§ãããå½é ããã SYN
|
---|
1377 | * ã»ã°ã¡ã³ããéä¿¡ãã¤ã¥ãããã¼ãéã§ã® ACK ã¹ãã¼ã ãé²ãã
|
---|
1378 | */
|
---|
1379 | if (cep->fsm_state == TCP_FSM_SYN_RECVD && (tcph->flags & TCP_FLG_ACK) &&
|
---|
1380 | (SEQ_GT(cep->snd_una, tcph->ack) ||
|
---|
1381 | SEQ_GT(tcph->ack, cep->snd_max)))
|
---|
1382 | return RET_RST_DROP;
|
---|
1383 |
|
---|
1384 | syscall(rel_net_buf(input));
|
---|
1385 |
|
---|
1386 | /* éä¿¡ãæ示ããã*/
|
---|
1387 | cep->flags |= TCP_CEP_FLG_ACK_NOW | TCP_CEP_FLG_POST_OUTPUT;
|
---|
1388 | sig_sem(SEM_TCP_POST_OUTPUT);
|
---|
1389 | return RET_RETURN;
|
---|
1390 | }
|
---|
1391 |
|
---|
1392 | /*
|
---|
1393 | * close_connection -- ã³ãã¯ã·ã§ã³éæ¾å¦çãç¸æãã FIN ãåä¿¡ããã
|
---|
1394 | */
|
---|
1395 |
|
---|
1396 | static void
|
---|
1397 | close_connection (T_TCP_CEP *cep, bool_t *needoutput)
|
---|
1398 | {
|
---|
1399 | if (TCP_FSM_HAVE_RCVD_FIN(cep->fsm_state) == 0) {
|
---|
1400 |
|
---|
1401 | #ifdef TCP_CFG_DELAY_ACK
|
---|
1402 |
|
---|
1403 | if (cep->flags & TCP_CEP_FLG_NEED_SYN)
|
---|
1404 | cep->flags |= TCP_CEP_FLG_DEL_ACK;
|
---|
1405 | else
|
---|
1406 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
1407 |
|
---|
1408 | #else/* of #ifdef TCP_CFG_DELAY_ACK */
|
---|
1409 |
|
---|
1410 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
1411 |
|
---|
1412 | #endif/* of #ifdef TCP_CFG_DELAY_ACK */
|
---|
1413 |
|
---|
1414 | cep->rcv_nxt ++;
|
---|
1415 | }
|
---|
1416 |
|
---|
1417 | switch (cep->fsm_state) {
|
---|
1418 | case TCP_FSM_SYN_RECVD: /* SYN ãåä¿¡ããSYN éä¿¡æ¸ã¿ */
|
---|
1419 | case TCP_FSM_ESTABLISHED: /* ã³ãã¯ã·ã§ã³éè¨å®äº */
|
---|
1420 | cep->fsm_state = TCP_FSM_CLOSE_WAIT;
|
---|
1421 | break;
|
---|
1422 |
|
---|
1423 | case TCP_FSM_FIN_WAIT_1: /* APP ãçµäºãFIN éä¿¡æ¸ã¿ãACK å¾
|
---|
1424 | ã¡ */
|
---|
1425 | cep->fsm_state = TCP_FSM_CLOSING;
|
---|
1426 | break;
|
---|
1427 |
|
---|
1428 | case TCP_FSM_FIN_WAIT_2: /* ç¸æããã® FIN å¾
|
---|
1429 | ã¡ */
|
---|
1430 | cep->fsm_state = TCP_FSM_TIME_WAIT;
|
---|
1431 | tcp_cancel_timers(cep);
|
---|
1432 | cep->timer[TCP_TIM_2MSL] = 2 * TCP_TVAL_MSL;
|
---|
1433 |
|
---|
1434 | /*
|
---|
1435 | * FIN WAIT 2 ç¶æ
|
---|
1436 | ã§ã¯ã
|
---|
1437 | * åä¿¡ã¯å¯è½ã§ãããããã§ã«éä¿¡ã¯çµäºãã¦ããã
|
---|
1438 | * ç¸æã®éä¿¡ãçµäºããã®ã§ãå
|
---|
1439 | ¥åã¿ã¹ã¯ã®ã¿èµ·åºããã
|
---|
1440 | */
|
---|
1441 | syscall(set_flg(cep->snd_flgid, TCP_CEP_EVT_SWBUF_READY));
|
---|
1442 |
|
---|
1443 | #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0
|
---|
1444 |
|
---|
1445 | /* ç¸æããã® FIN ã«å¯¾ãã¦å¿çãè¿ãã*/
|
---|
1446 | tcp_respond(NULL, cep, cep->rcv_nxt, cep->snd_una,
|
---|
1447 | cep->rbufsz - cep->rwbuf_count, TCP_FLG_ACK);
|
---|
1448 | cep->flags &= ~TCP_CEP_FLG_ACK_NOW;
|
---|
1449 | *needoutput = false;
|
---|
1450 |
|
---|
1451 | /*
|
---|
1452 | * å¿
|
---|
1453 | è¦ãªæ
|
---|
1454 | å ±ã Time Wait ç¨ TCP é信端ç¹ã«ç§»ãã¦ã
|
---|
1455 | * æ¨æºã® TCP é信端ç¹ãéæ¾ããã
|
---|
1456 | */
|
---|
1457 | tcp_move_twcep(cep);
|
---|
1458 |
|
---|
1459 | #endif /* of #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0 */
|
---|
1460 |
|
---|
1461 | break;
|
---|
1462 |
|
---|
1463 | case TCP_FSM_TIME_WAIT: /* ç¸æããã® FIN åä¿¡æ¸ã¿ãæéå¾
|
---|
1464 | ã¡ */
|
---|
1465 | cep->timer[TCP_TIM_2MSL] = 2 * TCP_TVAL_MSL;
|
---|
1466 | break;
|
---|
1467 | }
|
---|
1468 | }
|
---|
1469 |
|
---|
1470 | /*
|
---|
1471 | * tcp_input -- TCP ã®å
|
---|
1472 | ¥åé¢æ°
|
---|
1473 | *
|
---|
1474 | * 注æ: input ã«ã¯ IF ããã㨠IP ããããå
|
---|
1475 | é ã«ããã
|
---|
1476 | */
|
---|
1477 |
|
---|
1478 | uint_t
|
---|
1479 | tcp_input (T_NET_BUF **inputp, uint_t *offp, uint_t *nextp)
|
---|
1480 | {
|
---|
1481 | T_NET_BUF *input = *inputp;
|
---|
1482 | T_IP_HDR *iph;
|
---|
1483 | T_TCP_HDR *tcph;
|
---|
1484 | T_TCP_CEP *cep = NULL;
|
---|
1485 | T_TCP_SEQ iss = 0;
|
---|
1486 | ER ret;
|
---|
1487 | bool_t needoutput = false;
|
---|
1488 | int_t rbfree;
|
---|
1489 | int32_t todrop, win;
|
---|
1490 | uint16_t seglen;
|
---|
1491 | uint8_t flags;
|
---|
1492 |
|
---|
1493 | #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0
|
---|
1494 | T_TCP_TWCEP *twcep;
|
---|
1495 | #endif /* of #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0 */
|
---|
1496 |
|
---|
1497 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_OCTETS],
|
---|
1498 | input->len - GET_IF_IP_HDR_SIZE(input));
|
---|
1499 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_SEGS], 1);
|
---|
1500 | NET_COUNT_MIB(tcp_stats.tcpInSegs, 1);
|
---|
1501 |
|
---|
1502 | /* ãããé·ããã§ãã¯ããã*/
|
---|
1503 | if (input->len < IF_IP_TCP_HDR_SIZE) {
|
---|
1504 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_BAD_HEADERS], 1);
|
---|
1505 | goto drop;
|
---|
1506 | }
|
---|
1507 |
|
---|
1508 | iph = GET_IP_HDR(input);
|
---|
1509 | tcph = GET_TCP_HDR(input, *offp);
|
---|
1510 |
|
---|
1511 | seglen = input->len - *offp; /* TCP ã®ã»ã°ã¡ã³ãé· */
|
---|
1512 |
|
---|
1513 | if (IN_CKSUM(input, IPPROTO_TCP, *offp, (uint_t)seglen) != 0) {
|
---|
1514 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_BAD_CKSUMS], 1);
|
---|
1515 | goto drop;
|
---|
1516 | }
|
---|
1517 |
|
---|
1518 | /* TCP ãããé·ããã§ãã¯ããã*/
|
---|
1519 | if (TCP_HDR_LEN(tcph->doff) < TCP_HDR_SIZE || TCP_HDR_LEN(tcph->doff) > seglen) {
|
---|
1520 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_BAD_HEADERS], 1);
|
---|
1521 | goto drop;
|
---|
1522 | }
|
---|
1523 | tcph->sum = seglen - TCP_HDR_LEN(tcph->doff); /* ãããã tcph->sum 㯠TCP ã® SDU é· */
|
---|
1524 |
|
---|
1525 | /*
|
---|
1526 | * SYN 㨠FIN ã®ä¸¡ããããã»ããããã¦ããã°ç ´æ£ãããnmap çã®å¯¾ç
|
---|
1527 | * ãã ããRFC1644 T/TCP æ¡å¼µæ©è½ã¨ç«¶åããã
|
---|
1528 | */
|
---|
1529 | if ((tcph->flags & (TCP_FLG_SYN | TCP_FLG_FIN)) == (TCP_FLG_SYN | TCP_FLG_FIN))
|
---|
1530 | goto drop;
|
---|
1531 |
|
---|
1532 | /* ãããã¯ã¼ã¯ãªã¼ãã¼ãããã¹ããªã¼ãã¼ã«å¤æããã*/
|
---|
1533 |
|
---|
1534 | NTOHL(tcph->seq);
|
---|
1535 | NTOHL(tcph->ack);
|
---|
1536 | NTOHS(tcph->win);
|
---|
1537 | NTOHS(tcph->urp);
|
---|
1538 | NTOHS(tcph->sport);
|
---|
1539 | NTOHS(tcph->dport);
|
---|
1540 |
|
---|
1541 | find_cep:
|
---|
1542 |
|
---|
1543 | #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0
|
---|
1544 |
|
---|
1545 | /*
|
---|
1546 | * ç¶æ
|
---|
1547 | ã Time Wait ä¸ã® CEP ãæ¢ç´¢ããã
|
---|
1548 | */
|
---|
1549 | twcep = tcp_find_twcep(&iph->dst, tcph->dport, &iph->src, tcph->sport);
|
---|
1550 | if (twcep != NULL) {
|
---|
1551 |
|
---|
1552 | if (tcph->flags & TCP_FLG_RST) /* RST ãã©ã°ãåä¿¡ããã¨ãã¯ç¡è¦ããã*/
|
---|
1553 | goto drop;
|
---|
1554 | else {
|
---|
1555 |
|
---|
1556 | /*
|
---|
1557 | * TCP é信端ç¹ã Time Wait ã®æãç¸æãã¹ãããã»ã°ã¡ã³ããæ¥ãã¨ãã¯ã
|
---|
1558 | * ç¸æãã¹ãã® FIN ã«å¯¾ããèªãã¹ãã® ACK ã»ã°ã¡ã³ããéä¸ã§
|
---|
1559 | * æ失ãããã¨ãæå³ãã¦ããã®ã§ãACK ã»ã°ã¡ã³ããåéããã
|
---|
1560 | */
|
---|
1561 |
|
---|
1562 | /* ãã¹ããªã¼ãã¼ãããããã¯ã¼ã¯ãªã¼ãã¼ã«æ»ãã*/
|
---|
1563 | HTONS(tcph->sport);
|
---|
1564 | HTONS(tcph->dport);
|
---|
1565 |
|
---|
1566 | tcp_respond(input, NULL, twcep->rcv_nxt, twcep->snd_una, twcep->rbufsz - twcep->rwbuf_count, TCP_FLG_ACK);
|
---|
1567 | }
|
---|
1568 | return IPPROTO_DONE;
|
---|
1569 | }
|
---|
1570 | else
|
---|
1571 | /* æ¨æºã® TCP é信端ç¹ãå¾ãã*/
|
---|
1572 | cep = tcp_find_cep(&iph->dst, tcph->dport, &iph->src, tcph->sport);
|
---|
1573 |
|
---|
1574 | #else /* of #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0 */
|
---|
1575 |
|
---|
1576 | /* TCP é信端ç¹ãå¾ãã*/
|
---|
1577 | cep = tcp_find_cep(&iph->dst, tcph->dport, &iph->src, tcph->sport);
|
---|
1578 |
|
---|
1579 | #endif /* of #if defined(NUM_TCP_TW_CEP_ENTRY) && NUM_TCP_TW_CEP_ENTRY > 0 */
|
---|
1580 |
|
---|
1581 | /*
|
---|
1582 | * TCP é信端ç¹ããªãå ´å㨠CEP ã®ç¶æ
|
---|
1583 | ãã¯ãã¼ãºãªãç ´æ£ããã
|
---|
1584 | */
|
---|
1585 | if (cep == NULL) {
|
---|
1586 | syslog(LOG_INFO, "[TCP] unexp port: %d.", tcph->dport);
|
---|
1587 | goto reset_drop;
|
---|
1588 | }
|
---|
1589 |
|
---|
1590 | #ifdef TCP_CFG_TRACE
|
---|
1591 |
|
---|
1592 | tcp_input_trace(input, cep);
|
---|
1593 |
|
---|
1594 | #endif /* of #ifdef TCP_CFG_TRACE */
|
---|
1595 |
|
---|
1596 |
|
---|
1597 | if (cep->fsm_state == TCP_FSM_CLOSED)
|
---|
1598 | goto drop;
|
---|
1599 |
|
---|
1600 | /*
|
---|
1601 | * ã³ãã¯ã·ã§ã³éè¨æ¸ã¿ã§ã»ã°ã¡ã³ããåä¿¡ããã¨ãã¯ã
|
---|
1602 | * ã¢ã¤ãã«æéã¨çå確èªã¿ã¤ãããªã»ããããã
|
---|
1603 | */
|
---|
1604 | cep->idle = 0;
|
---|
1605 | if (TCP_FSM_HAVE_ESTABLISHED(cep->fsm_state)) {
|
---|
1606 | cep->timer[TCP_TIM_KEEP] = TCP_TVAL_KEEP_IDLE;
|
---|
1607 | }
|
---|
1608 |
|
---|
1609 | /* CEP ã®ç¶æ
|
---|
1610 | ã LISTEN 以å¤ã®æã¯ããªãã·ã§ã³ãå¦çããã*/
|
---|
1611 | if (cep->fsm_state != TCP_FSM_LISTEN)
|
---|
1612 | parse_option(tcph, cep);
|
---|
1613 |
|
---|
1614 | /*
|
---|
1615 | * åä¿¡å¯è½ã¦ã£ã³ããµã¤ãºãè¨ç®ããã
|
---|
1616 | *
|
---|
1617 | * rcv_nxt: åä¿¡ãæå¾
|
---|
1618 | ãã¦ããæå°ã® SEQï¼ãã以åã¯åä¿¡æ¸ã¿ï¼
|
---|
1619 | * rcv_adv: åä¿¡ãæå¾
|
---|
1620 | ãã¦ããæ大㮠SEQ
|
---|
1621 | * rbufsz: åä¿¡ã¦ã£ã³ããããã¡ãµã¤ãº
|
---|
1622 | * rwbuf_count: åä¿¡ã¦ã£ã³ããããã¡ã«ãããã¼ã¿é
|
---|
1623 | * tcph->sum: ä»ååä¿¡ãã SDU ãµã¤ãº
|
---|
1624 | *
|
---|
1625 | * ä»ååä¿¡ããã»ã°ã¡ã³ããé åºæ´åãã¥ã¼ã«é£çµãã
|
---|
1626 | * å¯è½æ§ãããã®ã§ tcph->sum ãèæ
|
---|
1627 | ®ããã
|
---|
1628 | *
|
---|
1629 | */
|
---|
1630 | win = cep->rbufsz - (cep->rwbuf_count + tcph->sum);
|
---|
1631 | if (win < 0)
|
---|
1632 | win = 0;
|
---|
1633 | if (win > (int32_t)(cep->rcv_adv - cep->rcv_nxt))
|
---|
1634 | cep->rcv_wnd = win;
|
---|
1635 | else
|
---|
1636 | cep->rcv_wnd = cep->rcv_adv - cep->rcv_nxt;
|
---|
1637 |
|
---|
1638 | /* CEP ã®ç¶æ
|
---|
1639 | ã«ããå¦çãè¡ãã*/
|
---|
1640 |
|
---|
1641 | if (cep->fsm_state == TCP_FSM_LISTEN) { /* ååãªã¼ãã³ (LISTEN) ã®å¦çã*/
|
---|
1642 | if ((ret = listening(input, cep, *offp, iss)) == RET_RST_DROP)
|
---|
1643 | goto reset_drop;
|
---|
1644 | else if (ret == RET_DROP)
|
---|
1645 | goto drop;
|
---|
1646 | trim_length(tcph, cep); /* åä¿¡ãã SDU é·ã調æ´ããã*/
|
---|
1647 |
|
---|
1648 | if (tcph->flags & TCP_FLG_ACK) { /* ACK ãã©ã°ã®å¦ç */
|
---|
1649 | if ((ret = proc_ack2(input, cep, *offp, &needoutput)) == RET_DROP)
|
---|
1650 | goto drop;
|
---|
1651 | else if (ret == RET_RST_DROP)
|
---|
1652 | goto reset_drop;
|
---|
1653 | else if (ret == RET_RETURN)
|
---|
1654 | return IPPROTO_DONE;
|
---|
1655 | }
|
---|
1656 | }
|
---|
1657 | else if (cep->fsm_state == TCP_FSM_SYN_SENT) { /* è½åãªã¼ãã³ãSYN éä¿¡æ¸ã¿ */
|
---|
1658 | if ((ret = syn_sent(tcph, cep)) == RET_RST_DROP)
|
---|
1659 | goto reset_drop;
|
---|
1660 | else if (ret == RET_DROP)
|
---|
1661 | goto drop;
|
---|
1662 | trim_length(tcph, cep); /* åä¿¡ãã SDU é·ã調æ´ããã*/
|
---|
1663 |
|
---|
1664 | if (tcph->flags & TCP_FLG_ACK) { /* ACK ãã©ã°ã®å¦ç */
|
---|
1665 | if ((ret = proc_ack2(input, cep, *offp, &needoutput)) == RET_DROP)
|
---|
1666 | goto drop;
|
---|
1667 | else if (ret == RET_RST_DROP)
|
---|
1668 | goto reset_drop;
|
---|
1669 | else if (ret == RET_RETURN)
|
---|
1670 | return IPPROTO_DONE;
|
---|
1671 | }
|
---|
1672 | }
|
---|
1673 | else {
|
---|
1674 | if (cep->fsm_state == TCP_FSM_SYN_RECVD) { /* SYN ãåä¿¡ãSYN éä¿¡æ¸ã¿ */
|
---|
1675 | /*
|
---|
1676 | * ç¸æããå信確èªãéããã¦æ¥ã¦ãã
|
---|
1677 | *
|
---|
1678 | * ACK <= æªç¢ºèªã®æå°éä¿¡ SEQ (snd_una) &&
|
---|
1679 | * éä¿¡ããæ大 SEQ (snd_max) < ACK
|
---|
1680 | *
|
---|
1681 | * ãªãããªã»ãããéã£ã¦ã»ã°ã¡ã³ããç ´æ£ããã
|
---|
1682 | */
|
---|
1683 | if ((tcph->flags & TCP_FLG_ACK) &&
|
---|
1684 | (SEQ_LE(tcph->ack, cep->snd_una) ||
|
---|
1685 | SEQ_GT(tcph->ack, cep->snd_max)))
|
---|
1686 | goto reset_drop;
|
---|
1687 | }
|
---|
1688 |
|
---|
1689 | /*
|
---|
1690 | * RST ãã©ã°ãåä¿¡ããã¨ãã®å¦ç (ç°å¸¸åæ)
|
---|
1691 | */
|
---|
1692 | if (tcph->flags & TCP_FLG_RST) {
|
---|
1693 | if (SEQ_GE(tcph->seq, cep->last_ack_sent) &&
|
---|
1694 | SEQ_LT(tcph->seq, cep->last_ack_sent + cep->rcv_wnd)) {
|
---|
1695 | /*
|
---|
1696 | * åä¿¡ããã»ã°ã¡ã³ãã® SEQ ããæå¾ã«éä¿¡ãã ACK (last_ack_sent)
|
---|
1697 | * ãããåä¿¡ã¦ã¤ã³ãã¦ãµã¤ãºã¾ã§ã®éã®å¦ç
|
---|
1698 | */
|
---|
1699 | switch (cep->fsm_state) {
|
---|
1700 | case TCP_FSM_SYN_RECVD: /* SYN ãåä¿¡ããSYN éä¿¡æ¸ã¿ */
|
---|
1701 |
|
---|
1702 | cep->net_error = EV_CNNRF; /* æ¥ç¶ä¸è½ */
|
---|
1703 | cep->error = E_CLS;
|
---|
1704 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_RSTS], 1);
|
---|
1705 | NET_COUNT_MIB(tcp_stats.tcpAttemptFails, 1);
|
---|
1706 | cep = tcp_close(cep);
|
---|
1707 | break;
|
---|
1708 |
|
---|
1709 | case TCP_FSM_ESTABLISHED: /* ã³ãã¯ã·ã§ã³éè¨å®äº */
|
---|
1710 | case TCP_FSM_CLOSE_WAIT: /* FIN åä¿¡ãã¯ãã¼ãºå¾
|
---|
1711 | ã¡ */
|
---|
1712 | NET_COUNT_MIB(tcp_stats.tcpEstabResets, 1);
|
---|
1713 | /* fallthrough */
|
---|
1714 |
|
---|
1715 | case TCP_FSM_FIN_WAIT_1: /* çµäºãã¦ãFIN éä¿¡æ¸ã¿ */
|
---|
1716 | case TCP_FSM_FIN_WAIT_2: /* çµäºãFIN ä¼é確èªåä¿¡ãFINå¾
|
---|
1717 | ã¡ */
|
---|
1718 |
|
---|
1719 | cep->net_error = EV_CNRST; /* æ¥ç¶ãªã»ãã */
|
---|
1720 | cep->error = E_CLS;
|
---|
1721 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_RSTS], 1);
|
---|
1722 | /* no break; */
|
---|
1723 |
|
---|
1724 | case TCP_FSM_CLOSING: /* çµäºãFIN 交ææ¸ã¿ãACK å¾
|
---|
1725 | ã¡ */
|
---|
1726 | case TCP_FSM_LAST_ACK: /* FIN åä¿¡ãçµäºãACK å¾
|
---|
1727 | ã¡ */
|
---|
1728 |
|
---|
1729 | cep = tcp_close(cep);
|
---|
1730 | break;
|
---|
1731 | }
|
---|
1732 | }
|
---|
1733 | goto drop;
|
---|
1734 | }
|
---|
1735 |
|
---|
1736 | /*
|
---|
1737 | * CEP ã®ç¶æ
|
---|
1738 | ã SYN ãåä¿¡ããSYN éä¿¡æ¸ã¿ã®å ´åã¯ã
|
---|
1739 | * åä¿¡ã¦ã£ã³ãã«åã¾ãããã«ãã¼ã¿ã
|
---|
1740 | * 調æ´ããåã«ããã®æ¥ç¶ã«ãããã±ãããã©ãããæ¤è¨¼ããã
|
---|
1741 | *
|
---|
1742 | * åä¿¡ããç¸æã® SEQ < ç¸æã® SEQ ã®åæå¤ (irs)
|
---|
1743 | *
|
---|
1744 | * ããã¯ã"LAND" DoS æ»æã®é²å¾¡ã§ããã
|
---|
1745 | */
|
---|
1746 | if (cep->fsm_state == TCP_FSM_SYN_RECVD && SEQ_LT(tcph->seq, cep->irs)) {
|
---|
1747 | goto reset_drop;
|
---|
1748 | }
|
---|
1749 |
|
---|
1750 | /*
|
---|
1751 | * åä¿¡ãæå¾
|
---|
1752 | ãã¦ããæå°ã® SEQ (rcv_nxt) - åä¿¡ããç¸æã® SEQ ã
|
---|
1753 | * æ£ãªããrcv_nxt 以åã®ãã¼ã¿ã¯ãã§ã«åä¿¡ãã¦ããã®ã§ããã®é¨åã
|
---|
1754 | * åé¤ããã
|
---|
1755 | * <---------- rcv_wnd --------->
|
---|
1756 | * rcv_nxt rcv_nxt + rcv_wnd
|
---|
1757 | * v v
|
---|
1758 | * -----+----------------------------+-----
|
---|
1759 | * | |
|
---|
1760 | * -----+----------------------------+-----
|
---|
1761 | * +----------------------+
|
---|
1762 | * |***************| |
|
---|
1763 | * +----------------------+
|
---|
1764 | * ^ ^
|
---|
1765 | * seq seq + len
|
---|
1766 | * <---------------> åé¤ããã
|
---|
1767 | */
|
---|
1768 | todrop = cep->rcv_nxt - tcph->seq;
|
---|
1769 | if (todrop > 0) {
|
---|
1770 |
|
---|
1771 | /*
|
---|
1772 | * SYN ãã©ã°ãã¤ãã¦ããã¨ãã¯ããã®å (1 ãªã¯ããã)
|
---|
1773 | * SEQ ãé²ããç·æ¥ãã¤ã³ã¿ã¨åé¤ããé·ãã調æ´ããã
|
---|
1774 | */
|
---|
1775 | if (tcph->flags & TCP_FLG_SYN) {
|
---|
1776 | tcph->flags &= ~TCP_FLG_SYN;
|
---|
1777 | tcph->seq ++;
|
---|
1778 | if (tcph->urp > 1)
|
---|
1779 | tcph->urp --;
|
---|
1780 | else
|
---|
1781 | tcph->flags &= ~TCP_FLG_URG;
|
---|
1782 | todrop --;
|
---|
1783 | }
|
---|
1784 |
|
---|
1785 | /*
|
---|
1786 | * åé¤ããé·ãã SDU ããé·ããã¤ã¾ããåä¿¡ãæå¾
|
---|
1787 | ãã¦ãã
|
---|
1788 | * æå°ã® SEQ (rcv_nxt) ã«éãã¦ããªããã
|
---|
1789 | * åé¤ããé·ãã SDU ã¨åãã§ãFIN ãã©ã°ãã¤ãã¦ãªããã°
|
---|
1790 | * å
|
---|
1791 | ¨ã¦åé¤ããã
|
---|
1792 | */
|
---|
1793 | if ( todrop > tcph->sum || /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1794 | (todrop == tcph->sum && (tcph->flags & TCP_FLG_FIN) == 0)) {
|
---|
1795 | tcph->flags &= ~TCP_FLG_FIN;
|
---|
1796 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
1797 | todrop = tcph->sum; /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1798 | }
|
---|
1799 |
|
---|
1800 | /*
|
---|
1801 | * SDU ãåã«è©°ããã
|
---|
1802 | */
|
---|
1803 | if (todrop < tcph->sum) { /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1804 | memcpy(GET_TCP_SDU(input, *offp),
|
---|
1805 | GET_TCP_SDU(input, *offp) + todrop, (size_t)(tcph->sum - todrop));
|
---|
1806 | }
|
---|
1807 |
|
---|
1808 | /*
|
---|
1809 | * SEQ 㨠SDU é·ã調æ´ããã
|
---|
1810 | */
|
---|
1811 | tcph->seq += todrop;
|
---|
1812 | tcph->sum -= (uint16_t)todrop; /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1813 |
|
---|
1814 | /*
|
---|
1815 | * ç·æ¥ãã¤ã³ã¿ã調æ´ããã
|
---|
1816 | */
|
---|
1817 | if (tcph->urp > todrop)
|
---|
1818 | tcph->urp -= (uint16_t)todrop;
|
---|
1819 | else {
|
---|
1820 | tcph->flags &= ~TCP_FLG_URG;
|
---|
1821 | tcph->urp = 0;
|
---|
1822 | }
|
---|
1823 |
|
---|
1824 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_DUP_SEGS], 1);
|
---|
1825 | }
|
---|
1826 |
|
---|
1827 | /*
|
---|
1828 | * ããã¦ã¼ã¶ã¿ã¹ã¯ãçµäºããå¾ã«ããã¼ã¿ãåä¿¡ãã
|
---|
1829 | * å ´åã¯ãRST ãéãã
|
---|
1830 | */
|
---|
1831 | if (cep->fsm_state == TCP_FSM_LAST_ACK && tcph->sum > 0) { /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1832 | cep = tcp_close(cep);
|
---|
1833 | goto reset_drop;
|
---|
1834 | }
|
---|
1835 |
|
---|
1836 | /*
|
---|
1837 | * åä¿¡ã»ã°ã¡ã³ããåä¿¡ã¦ã£ã³ããè¶
|
---|
1838 | ããå ´åã¯ã
|
---|
1839 | * è¶
|
---|
1840 | ããåãåãã
|
---|
1841 | *
|
---|
1842 | * <---------- rcv_wnd --------->
|
---|
1843 | * rcv_nxt (rcv_nxt + rcv_wnd)
|
---|
1844 | * v v
|
---|
1845 | * -----+----------------------------+-----
|
---|
1846 | * | |
|
---|
1847 | * -----+----------------------------+-----
|
---|
1848 | * +----------------------+
|
---|
1849 | * | |******|
|
---|
1850 | * +----------------------+
|
---|
1851 | * ^ ^
|
---|
1852 | * seq seq + len
|
---|
1853 | * <-----> åé¤ããã
|
---|
1854 | */
|
---|
1855 | todrop = (tcph->seq + tcph->sum) - (cep->rcv_nxt + cep->rcv_wnd); /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1856 | if (todrop > 0) {
|
---|
1857 | if (todrop > tcph->sum) { /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1858 | /*
|
---|
1859 | * åä¿¡ãã SDU ã®å
|
---|
1860 | ¨ã¦ãåä¿¡ã¦ã£ã³ããè¶
|
---|
1861 | ããå ´åã
|
---|
1862 | *
|
---|
1863 | * TIME_WAIT ä¸ã«ãæ°ããªæ¥ç¶è¦æ±ãåä¿¡ããã
|
---|
1864 | * å¤ãæ¥ç¶ãç ´æ£ããæ°ããªæ¥ç¶ãéå§ããã
|
---|
1865 | * ãã ããSEQ ã¯åããé²ãã§ããªããã°ãªããªãã
|
---|
1866 | */
|
---|
1867 | if ((tcph->flags & TCP_FLG_SYN) &&
|
---|
1868 | cep->fsm_state == TCP_FSM_TIME_WAIT &&
|
---|
1869 | SEQ_GT(tcph->seq, cep->rcv_nxt)) {
|
---|
1870 | iss = cep->snd_nxt + TCP_ISS_INCR();
|
---|
1871 | tcp_close(cep);
|
---|
1872 | syscall(dly_tsk(0));
|
---|
1873 | goto find_cep;
|
---|
1874 | }
|
---|
1875 |
|
---|
1876 | /*
|
---|
1877 | * åä¿¡ã¦ã£ã³ãã 0 ã§ãåä¿¡ãã SEQ ã¨
|
---|
1878 | * åä¿¡ãæå¾
|
---|
1879 | ãã¦ããæå°ã® SEQ ãä¸è´ããã¨ãã¯
|
---|
1880 | * ACK ãè¿ãããã以å¤ã¯ãã¼ã¿ãç ´æ£ããACK ãè¿ãã
|
---|
1881 | */
|
---|
1882 | if (cep->rcv_wnd == 0 && (tcph->seq == cep->rcv_nxt || tcph->sum == 0)) {
|
---|
1883 | cep->flags |= TCP_CEP_FLG_ACK_NOW;
|
---|
1884 | }
|
---|
1885 | else if (drop_after_ack(input, cep, *offp) == RET_RST_DROP)
|
---|
1886 | goto reset_drop;
|
---|
1887 | else {
|
---|
1888 | return IPPROTO_DONE;
|
---|
1889 | }
|
---|
1890 | }
|
---|
1891 | tcph->sum -= (uint16_t)todrop; /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1892 | tcph->flags &= ~(TCP_FLG_PUSH | TCP_FLG_FIN);
|
---|
1893 | }
|
---|
1894 |
|
---|
1895 | /*
|
---|
1896 | * ãããSYN ãã»ããããã¦ããã°ã
|
---|
1897 | * ã¨ã©ã¼ãªã®ã§ RST ãéããæ¥ç¶ãç ´æ£ããã
|
---|
1898 | */
|
---|
1899 | if (tcph->flags & TCP_FLG_SYN) {
|
---|
1900 | cep->net_error = EV_CNRST;
|
---|
1901 | cep = tcp_drop(cep, E_CLS);
|
---|
1902 | goto reset_drop;
|
---|
1903 | }
|
---|
1904 |
|
---|
1905 | /*
|
---|
1906 | * ãããACK ãã»ããããã¦ããªãå ´åã¯ã
|
---|
1907 | * ç¶æ
|
---|
1908 | ã SYN åä¿¡æ¸ã¿ã
|
---|
1909 | * SYN ãéä¿¡ãããã¨ãã¦ããã°ãå¦çãç¶ãããã
|
---|
1910 | * ãã以å¤ã¯ã»ã°ã¡ã³ããç ´æ£ãã¦çµäºããã
|
---|
1911 | */
|
---|
1912 | if ((tcph->flags & TCP_FLG_ACK) == 0) {
|
---|
1913 | if (!(cep->fsm_state == TCP_FSM_SYN_RECVD || (cep->flags & TCP_CEP_FLG_NEED_SYN)))
|
---|
1914 | goto drop;
|
---|
1915 | }
|
---|
1916 | else {
|
---|
1917 | /*
|
---|
1918 | * ACK ã®å¦ç
|
---|
1919 | */
|
---|
1920 | ret = proc_ack1(input, cep, *offp, &needoutput);
|
---|
1921 | if (ret == RET_DROP)
|
---|
1922 | goto drop;
|
---|
1923 | else if (ret == RET_RST_DROP)
|
---|
1924 | goto reset_drop;
|
---|
1925 | else if (ret == RET_RETURN)
|
---|
1926 | return IPPROTO_DONE;
|
---|
1927 | }
|
---|
1928 | }
|
---|
1929 |
|
---|
1930 | /* step 6 */
|
---|
1931 |
|
---|
1932 | /* éä¿¡ã¦ã£ã³ããæ´æ°ããã*/
|
---|
1933 | if (update_wnd(tcph, cep) == true)
|
---|
1934 | needoutput = true;
|
---|
1935 |
|
---|
1936 | /* ç·æ¥ãã¼ã¿ãå¦çããã*/
|
---|
1937 | proc_urg(tcph, cep);
|
---|
1938 |
|
---|
1939 | /* do data */
|
---|
1940 |
|
---|
1941 | /*
|
---|
1942 | * SDU ãããããFIN ãæªåä¿¡ã®ç¶æ
|
---|
1943 | ã§ãæåã« FIN ãåä¿¡ããã¨ãã
|
---|
1944 | * åä¿¡ã»ã°ã¡ã³ããã¥ã¼ã« net_buf ã追å ããã
|
---|
1945 | * ãã以å¤ã®å ´åã¯ãã»ã°ã¡ã³ããç ´æ£ããã
|
---|
1946 | */
|
---|
1947 | flags = tcph->flags;
|
---|
1948 | if ((tcph->sum > 0 || (flags & TCP_FLG_FIN)) && /* tcph->sum 㯠TCP ã® SDU é· */
|
---|
1949 | TCP_FSM_HAVE_RCVD_FIN(cep->fsm_state) == 0) {
|
---|
1950 | flags = reassemble(input, cep, *offp, flags);
|
---|
1951 | }
|
---|
1952 | else {
|
---|
1953 | syscall(rel_net_buf(input));
|
---|
1954 | flags &= ~TCP_FLG_FIN;
|
---|
1955 | }
|
---|
1956 |
|
---|
1957 | /*
|
---|
1958 | * FIN ãåä¿¡ãããã³ãã¯ã·ã§ã³ãã¯ãã¼ãºããã
|
---|
1959 | */
|
---|
1960 | if (flags & TCP_FLG_FIN)
|
---|
1961 | close_connection(cep, &needoutput);
|
---|
1962 |
|
---|
1963 | /* åºåãè¡ã£ãå¾çµäºããã*/
|
---|
1964 | if (needoutput == true || (cep->flags & TCP_CEP_FLG_ACK_NOW)) {
|
---|
1965 | /* éä¿¡ãæ示ããã*/
|
---|
1966 | cep->flags |= TCP_CEP_FLG_POST_OUTPUT;
|
---|
1967 | sig_sem(SEM_TCP_POST_OUTPUT);
|
---|
1968 | }
|
---|
1969 |
|
---|
1970 | return IPPROTO_DONE;
|
---|
1971 |
|
---|
1972 | reset_drop:
|
---|
1973 | /*
|
---|
1974 | * RST éä¿¡å¦ç
|
---|
1975 | */
|
---|
1976 |
|
---|
1977 | if ((tcph->flags & TCP_FLG_RST) || IN_IS_NET_ADDR_MULTICAST(&iph->dst))
|
---|
1978 | goto drop;
|
---|
1979 |
|
---|
1980 | /* ãã¹ããªã¼ãã¼ãããããã¯ã¼ã¯ãªã¼ãã¼ã«æ»ãã*/
|
---|
1981 |
|
---|
1982 | HTONS(tcph->sport);
|
---|
1983 | HTONS(tcph->dport);
|
---|
1984 |
|
---|
1985 | if (cep == NULL)
|
---|
1986 | rbfree = 0;
|
---|
1987 | else
|
---|
1988 | rbfree = cep->rbufsz - cep->rwbuf_count;
|
---|
1989 |
|
---|
1990 | if (tcph->flags & TCP_FLG_ACK) {
|
---|
1991 | tcp_respond(input, cep, 0, tcph->ack, rbfree, TCP_FLG_RST);
|
---|
1992 | }
|
---|
1993 | else {
|
---|
1994 | if (tcph->flags & TCP_FLG_SYN)
|
---|
1995 | tcph->sum ++; /* tcph->sum 㯠SDU é· */
|
---|
1996 | tcp_respond(input, cep, tcph->seq + tcph->sum, 0, rbfree, TCP_FLG_RST | TCP_FLG_ACK);
|
---|
1997 | }
|
---|
1998 |
|
---|
1999 | /* input 㯠tcp_respoond ã§è¿å´ãããã*/
|
---|
2000 | NET_COUNT_TCP(net_count_tcp[NC_TCP_SEND_RSTS], 1);
|
---|
2001 | NET_COUNT_MIB(tcp_stats.tcpOutRsts, 1);
|
---|
2002 | return IPPROTO_DONE;
|
---|
2003 |
|
---|
2004 | drop:
|
---|
2005 | NET_COUNT_TCP(net_count_tcp[NC_TCP_RECV_DROP_SEGS], 1);
|
---|
2006 | NET_COUNT_MIB(tcp_stats.tcpInErrs, 1);
|
---|
2007 | syscall(rel_net_buf(input));
|
---|
2008 | return IPPROTO_DONE;
|
---|
2009 | }
|
---|
2010 |
|
---|
2011 | #endif /* of #ifdef SUPPORT_TCP */
|
---|