1 | /* |
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2 | * Copyright (c) 1993 Daniel Boulet |
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3 | * Copyright (c) 1994 Ugen J.S.Antsilevich |
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4 | * |
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5 | * Redistribution and use in source forms, with and without modification, |
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6 | * are permitted provided that this entire comment appears intact. |
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7 | * |
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8 | * Redistribution in binary form may occur without any restrictions. |
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9 | * Obviously, it would be nice if you gave credit where credit is due |
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10 | * but requiring it would be too onerous. |
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11 | * |
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12 | * This software is provided ``AS IS'' without any warranties of any kind. |
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13 | * |
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14 | * $Id$ |
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15 | */ |
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16 | |
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17 | #ifndef _IP_FW_H |
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18 | #define _IP_FW_H |
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19 | |
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20 | #include <net/if.h> |
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21 | |
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22 | /* |
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23 | * This union structure identifies an interface, either explicitly |
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24 | * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME |
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25 | * and IP_FW_F_OIFNAME say how to interpret this structure. An |
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26 | * interface unit number of -1 matches any unit number, while an |
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27 | * IP address of 0.0.0.0 indicates matches any interface. |
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28 | * |
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29 | * The receive and transmit interfaces are only compared against the |
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30 | * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE) |
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31 | * is set. Note some packets lack a receive or transmit interface |
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32 | * (in which case the missing "interface" never matches). |
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33 | */ |
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34 | |
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35 | union ip_fw_if { |
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36 | struct in_addr fu_via_ip; /* Specified by IP address */ |
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37 | struct { /* Specified by interface name */ |
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38 | #define FW_IFNLEN IFNAMSIZ |
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39 | char name[FW_IFNLEN]; |
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40 | short unit; /* -1 means match any unit */ |
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41 | } fu_via_if; |
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42 | }; |
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43 | |
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44 | /* |
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45 | * Format of an IP firewall descriptor |
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46 | * |
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47 | * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order. |
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48 | * fw_flg and fw_n*p are stored in host byte order (of course). |
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49 | * Port numbers are stored in HOST byte order. |
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50 | * Warning: setsockopt() will fail if sizeof(struct ip_fw) > MLEN (108) |
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51 | */ |
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52 | |
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53 | struct ip_fw { |
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54 | u_long fw_pcnt,fw_bcnt; /* Packet and byte counters */ |
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55 | struct in_addr fw_src, fw_dst; /* Source and destination IP addr */ |
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56 | struct in_addr fw_smsk, fw_dmsk; /* Mask for src and dest IP addr */ |
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57 | u_short fw_number; /* Rule number */ |
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58 | u_short fw_flg; /* Flags word */ |
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59 | #define IP_FW_MAX_PORTS 10 /* A reasonable maximum */ |
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60 | u_short fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */ |
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61 | u_char fw_ipopt,fw_ipnopt; /* IP options set/unset */ |
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62 | u_char fw_tcpf,fw_tcpnf; /* TCP flags set/unset */ |
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63 | #define IP_FW_ICMPTYPES_DIM (32 / (sizeof(unsigned) * 8)) |
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64 | unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */ |
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65 | long timestamp; /* timestamp (tv_sec) of last match */ |
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66 | union ip_fw_if fw_in_if, fw_out_if; /* Incoming and outgoing interfaces */ |
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67 | union { |
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68 | u_short fu_divert_port; /* Divert/tee port (options IPDIVERT) */ |
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69 | u_short fu_skipto_rule; /* SKIPTO command rule number */ |
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70 | u_short fu_reject_code; /* REJECT response code */ |
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71 | } fw_un; |
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72 | u_char fw_prot; /* IP protocol */ |
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73 | u_char fw_nports; /* N'of src ports and # of dst ports */ |
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74 | /* in ports array (dst ports follow */ |
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75 | /* src ports; max of 10 ports in all; */ |
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76 | /* count of 0 means match all ports) */ |
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77 | }; |
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78 | |
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79 | #define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f) |
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80 | #define IP_FW_SETNSRCP(rule, n) do { \ |
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81 | (rule)->fw_nports &= ~0x0f; \ |
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82 | (rule)->fw_nports |= (n); \ |
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83 | } while (0) |
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84 | #define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4) |
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85 | #define IP_FW_SETNDSTP(rule, n) do { \ |
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86 | (rule)->fw_nports &= ~0xf0; \ |
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87 | (rule)->fw_nports |= (n) << 4;\ |
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88 | } while (0) |
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89 | |
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90 | #define fw_divert_port fw_un.fu_divert_port |
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91 | #define fw_skipto_rule fw_un.fu_skipto_rule |
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92 | #define fw_reject_code fw_un.fu_reject_code |
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93 | |
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94 | struct ip_fw_chain { |
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95 | LIST_ENTRY(ip_fw_chain) chain; |
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96 | struct ip_fw *rule; |
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97 | }; |
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98 | |
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99 | /* |
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100 | * Values for "flags" field . |
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101 | */ |
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102 | #define IP_FW_F_IN 0x0001 /* Check inbound packets */ |
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103 | #define IP_FW_F_OUT 0x0002 /* Check outbound packets */ |
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104 | #define IP_FW_F_IIFACE 0x0004 /* Apply inbound interface test */ |
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105 | #define IP_FW_F_OIFACE 0x0008 /* Apply outbound interface test */ |
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106 | |
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107 | #define IP_FW_F_COMMAND 0x0070 /* Mask for type of chain entry: */ |
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108 | #define IP_FW_F_DENY 0x0000 /* This is a deny rule */ |
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109 | #define IP_FW_F_REJECT 0x0010 /* Deny and send a response packet */ |
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110 | #define IP_FW_F_ACCEPT 0x0020 /* This is an accept rule */ |
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111 | #define IP_FW_F_COUNT 0x0030 /* This is a count rule */ |
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112 | #define IP_FW_F_DIVERT 0x0040 /* This is a divert rule */ |
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113 | #define IP_FW_F_TEE 0x0050 /* This is a tee rule */ |
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114 | #define IP_FW_F_SKIPTO 0x0060 /* This is a skipto rule */ |
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115 | |
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116 | #define IP_FW_F_PRN 0x0080 /* Print if this rule matches */ |
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117 | |
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118 | #define IP_FW_F_SRNG 0x0100 /* The first two src ports are a min * |
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119 | * and max range (stored in host byte * |
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120 | * order). */ |
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121 | |
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122 | #define IP_FW_F_DRNG 0x0200 /* The first two dst ports are a min * |
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123 | * and max range (stored in host byte * |
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124 | * order). */ |
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125 | |
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126 | #define IP_FW_F_IIFNAME 0x0400 /* In interface by name/unit (not IP) */ |
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127 | #define IP_FW_F_OIFNAME 0x0800 /* Out interface by name/unit (not IP) */ |
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128 | |
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129 | #define IP_FW_F_INVSRC 0x1000 /* Invert sense of src check */ |
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130 | #define IP_FW_F_INVDST 0x2000 /* Invert sense of dst check */ |
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131 | |
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132 | #define IP_FW_F_FRAG 0x4000 /* Fragment */ |
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133 | |
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134 | #define IP_FW_F_ICMPBIT 0x8000 /* ICMP type bitmap is valid */ |
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135 | |
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136 | #define IP_FW_F_MASK 0xFFFF /* All possible flag bits mask */ |
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137 | |
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138 | /* |
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139 | * For backwards compatibility with rules specifying "via iface" but |
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140 | * not restricted to only "in" or "out" packets, we define this combination |
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141 | * of bits to represent this configuration. |
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142 | */ |
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143 | |
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144 | #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) |
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145 | |
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146 | /* |
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147 | * Definitions for REJECT response codes. |
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148 | * Values less than 256 correspond to ICMP unreachable codes. |
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149 | */ |
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150 | #define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ |
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151 | |
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152 | /* |
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153 | * Definitions for IP option names. |
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154 | */ |
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155 | #define IP_FW_IPOPT_LSRR 0x01 |
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156 | #define IP_FW_IPOPT_SSRR 0x02 |
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157 | #define IP_FW_IPOPT_RR 0x04 |
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158 | #define IP_FW_IPOPT_TS 0x08 |
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159 | |
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160 | /* |
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161 | * Definitions for TCP flags. |
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162 | */ |
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163 | #define IP_FW_TCPF_FIN TH_FIN |
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164 | #define IP_FW_TCPF_SYN TH_SYN |
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165 | #define IP_FW_TCPF_RST TH_RST |
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166 | #define IP_FW_TCPF_PSH TH_PUSH |
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167 | #define IP_FW_TCPF_ACK TH_ACK |
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168 | #define IP_FW_TCPF_URG TH_URG |
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169 | #define IP_FW_TCPF_ESTAB 0x40 |
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170 | |
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171 | /* |
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172 | * Main firewall chains definitions and global var's definitions. |
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173 | */ |
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174 | #ifdef KERNEL |
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175 | |
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176 | /* |
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177 | * Function definitions. |
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178 | */ |
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179 | void ip_fw_init(void); |
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180 | |
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181 | #endif /* KERNEL */ |
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182 | |
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183 | #endif /* _IP_FW_H */ |
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