1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * DHCPv6 client.
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4 | *
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5 | * 2011-11.
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6 | * WARNING: THIS CODE IS INCOMPLETE. IT IS NOWHERE NEAR
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7 | * TO BE READY FOR PRODUCTION USE.
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8 | *
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9 | * Copyright (C) 2011 Denys Vlasenko.
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10 | *
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11 | * Licensed under GPLv2, see file LICENSE in this source tree.
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12 | */
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13 |
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14 | //config:config UDHCPC6
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15 | //config: bool "udhcp client for DHCPv6 (udhcpc6)"
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16 | //config: default n # not yet ready
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17 | //config: depends on FEATURE_IPV6
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18 | //config: help
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19 | //config: udhcpc6 is a DHCPv6 client
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20 |
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21 | //applet:IF_UDHCPC6(APPLET(udhcpc6, BB_DIR_USR_BIN, BB_SUID_DROP))
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22 |
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23 | //kbuild:lib-$(CONFIG_UDHCPC6) += d6_dhcpc.o d6_packet.o d6_socket.o common.o socket.o signalpipe.o
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24 |
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25 |
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26 | #include <syslog.h>
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27 | /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
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28 | #define WANT_PIDFILE 1
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29 | #include "common.h"
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30 | #include "dhcpd.h"
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31 | #include "dhcpc.h"
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32 | #include "d6_common.h"
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33 |
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34 | #include <netinet/if_ether.h>
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35 | #include <netpacket/packet.h>
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36 | #include <linux/filter.h>
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37 |
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38 | /* "struct client_config_t client_config" is in bb_common_bufsiz1 */
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39 |
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40 |
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41 | #if ENABLE_LONG_OPTS
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42 | static const char udhcpc6_longopts[] ALIGN1 =
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43 | "interface\0" Required_argument "i"
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44 | "now\0" No_argument "n"
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45 | "pidfile\0" Required_argument "p"
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46 | "quit\0" No_argument "q"
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47 | "release\0" No_argument "R"
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48 | "request\0" Required_argument "r"
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49 | "script\0" Required_argument "s"
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50 | "timeout\0" Required_argument "T"
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51 | "retries\0" Required_argument "t"
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52 | "tryagain\0" Required_argument "A"
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53 | "syslog\0" No_argument "S"
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54 | "request-option\0" Required_argument "O"
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55 | "no-default-options\0" No_argument "o"
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56 | "foreground\0" No_argument "f"
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57 | "background\0" No_argument "b"
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58 | /// IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
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59 | IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
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60 | ;
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61 | #endif
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62 | /* Must match getopt32 option string order */
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63 | enum {
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64 | OPT_i = 1 << 0,
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65 | OPT_n = 1 << 1,
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66 | OPT_p = 1 << 2,
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67 | OPT_q = 1 << 3,
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68 | OPT_R = 1 << 4,
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69 | OPT_r = 1 << 5,
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70 | OPT_s = 1 << 6,
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71 | OPT_T = 1 << 7,
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72 | OPT_t = 1 << 8,
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73 | OPT_S = 1 << 9,
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74 | OPT_A = 1 << 10,
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75 | OPT_O = 1 << 11,
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76 | OPT_o = 1 << 12,
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77 | OPT_x = 1 << 13,
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78 | OPT_f = 1 << 14,
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79 | /* The rest has variable bit positions, need to be clever */
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80 | OPTBIT_f = 14,
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81 | USE_FOR_MMU( OPTBIT_b,)
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82 | ///IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
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83 | IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
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84 | USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
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85 | ///IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
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86 | IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
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87 | };
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88 |
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89 |
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90 | /*** Utility functions ***/
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91 |
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92 | static void *d6_find_option(uint8_t *option, uint8_t *option_end, unsigned code)
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93 | {
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94 | /* "length minus 4" */
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95 | int len_m4 = option_end - option - 4;
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96 | while (len_m4 >= 0) {
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97 | /* Next option's len is too big? */
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98 | if (option[3] > len_m4)
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99 | return NULL; /* yes. bogus packet! */
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100 | /* So far we treat any opts with code >255
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101 | * or len >255 as bogus, and stop at once.
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102 | * This simplifies big-endian handling.
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103 | */
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104 | if (option[0] != 0 || option[2] != 0)
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105 | return NULL;
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106 | /* Option seems to be valid */
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107 | /* Does its code match? */
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108 | if (option[1] == code)
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109 | return option; /* yes! */
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110 | option += option[3] + 4;
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111 | len_m4 -= option[3] + 4;
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112 | }
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113 | return NULL;
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114 | }
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115 |
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116 | static void *d6_copy_option(uint8_t *option, uint8_t *option_end, unsigned code)
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117 | {
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118 | uint8_t *opt = d6_find_option(option, option_end, code);
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119 | if (!opt)
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120 | return opt;
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121 | return xmemdup(opt, opt[3] + 4);
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122 | }
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123 |
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124 | static void *d6_store_blob(void *dst, const void *src, unsigned len)
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125 | {
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126 | memcpy(dst, src, len);
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127 | return dst + len;
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128 | }
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129 |
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130 |
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131 | /*** Script execution code ***/
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132 |
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133 | static char** new_env(void)
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134 | {
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135 | client6_data.env_ptr = xrealloc_vector(client6_data.env_ptr, 3, client6_data.env_idx);
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136 | return &client6_data.env_ptr[client6_data.env_idx++];
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137 | }
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138 |
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139 | /* put all the parameters into the environment */
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140 | static void option_to_env(uint8_t *option, uint8_t *option_end)
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141 | {
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142 | /* "length minus 4" */
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143 | int len_m4 = option_end - option - 4;
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144 | while (len_m4 >= 0) {
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145 | uint32_t v32;
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146 | char ipv6str[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff")];
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147 |
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148 | if (option[0] != 0 || option[2] != 0)
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149 | break;
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150 |
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151 | switch (option[1]) {
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152 | //case D6_OPT_CLIENTID:
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153 | //case D6_OPT_SERVERID:
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154 | case D6_OPT_IA_NA:
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155 | case D6_OPT_IA_PD:
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156 | option_to_env(option + 16, option + 4 + option[3]);
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157 | break;
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158 | //case D6_OPT_IA_TA:
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159 | case D6_OPT_IAADDR:
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160 | /* 0 1 2 3
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161 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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162 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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163 | * | OPTION_IAADDR | option-len |
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164 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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165 | * | |
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166 | * | IPv6 address |
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167 | * | |
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168 | * | |
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169 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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170 | * | preferred-lifetime |
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171 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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172 | * | valid-lifetime |
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173 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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174 | */
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175 | sprint_nip6(ipv6str, option + 4);
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176 | *new_env() = xasprintf("ipv6=%s", ipv6str);
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177 |
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178 | move_from_unaligned32(v32, option + 4 + 16 + 4);
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179 | *new_env() = xasprintf("lease=%u", (unsigned)v32);
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180 | break;
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181 |
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182 | //case D6_OPT_ORO:
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183 | //case D6_OPT_PREFERENCE:
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184 | //case D6_OPT_ELAPSED_TIME:
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185 | //case D6_OPT_RELAY_MSG:
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186 | //case D6_OPT_AUTH:
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187 | //case D6_OPT_UNICAST:
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188 | //case D6_OPT_STATUS_CODE:
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189 | //case D6_OPT_RAPID_COMMIT:
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190 | //case D6_OPT_USER_CLASS:
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191 | //case D6_OPT_VENDOR_CLASS:
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192 | //case D6_OPT_VENDOR_OPTS:
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193 | //case D6_OPT_INTERFACE_ID:
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194 | //case D6_OPT_RECONF_MSG:
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195 | //case D6_OPT_RECONF_ACCEPT:
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196 |
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197 | case D6_OPT_IAPREFIX:
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198 | /* 0 1 2 3
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199 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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200 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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201 | * | OPTION_IAPREFIX | option-length |
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202 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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203 | * | preferred-lifetime |
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204 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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205 | * | valid-lifetime |
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206 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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207 | * | prefix-length | |
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208 | * +-+-+-+-+-+-+-+-+ IPv6 prefix |
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209 | * | (16 octets) |
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210 | * | |
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211 | * | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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212 | * | |
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213 | * +-+-+-+-+-+-+-+-+
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214 | */
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215 | //move_from_unaligned32(v32, option + 4 + 4);
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216 | //*new_env() = xasprintf("lease=%u", (unsigned)v32);
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217 |
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218 | sprint_nip6(ipv6str, option + 4 + 4 + 1);
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219 | *new_env() = xasprintf("ipv6prefix=%s/%u", ipv6str, (unsigned)(option[4 + 4]));
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220 | }
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221 | option += 4 + option[3];
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222 | len_m4 -= 4 + option[3];
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223 | }
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224 | }
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225 |
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226 | static char **fill_envp(struct d6_packet *packet)
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227 | {
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228 | char **envp, **curr;
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229 |
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230 | client6_data.env_ptr = NULL;
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231 | client6_data.env_idx = 0;
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232 |
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233 | *new_env() = xasprintf("interface=%s", client_config.interface);
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234 |
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235 | if (packet)
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236 | option_to_env(packet->d6_options, packet->d6_options + sizeof(packet->d6_options));
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237 |
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238 | envp = curr = client6_data.env_ptr;
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239 | while (*curr)
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240 | putenv(*curr++);
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241 |
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242 | return envp;
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243 | }
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244 |
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245 | /* Call a script with a par file and env vars */
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246 | static void d6_run_script(struct d6_packet *packet, const char *name)
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247 | {
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248 | char **envp, **curr;
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249 | char *argv[3];
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250 |
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251 | envp = fill_envp(packet);
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252 |
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253 | /* call script */
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254 | log1("executing %s %s", client_config.script, name);
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255 | argv[0] = (char*) client_config.script;
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256 | argv[1] = (char*) name;
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257 | argv[2] = NULL;
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258 | spawn_and_wait(argv);
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259 |
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260 | for (curr = envp; *curr; curr++) {
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261 | log2(" %s", *curr);
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262 | bb_unsetenv_and_free(*curr);
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263 | }
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264 | free(envp);
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265 | }
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266 |
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267 |
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268 | /*** Sending/receiving packets ***/
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269 |
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270 | static ALWAYS_INLINE uint32_t random_xid(void)
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271 | {
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272 | uint32_t t = rand() & htonl(0x00ffffff);
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273 | return t;
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274 | }
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275 |
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276 | /* Initialize the packet with the proper defaults */
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277 | static uint8_t *init_d6_packet(struct d6_packet *packet, char type, uint32_t xid)
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278 | {
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279 | struct d6_option *clientid;
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280 |
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281 | memset(packet, 0, sizeof(*packet));
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282 |
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283 | packet->d6_xid32 = xid;
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284 | packet->d6_msg_type = type;
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285 |
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286 | clientid = (void*)client_config.clientid;
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287 | return d6_store_blob(packet->d6_options, clientid, clientid->len + 2+2);
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288 | }
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289 |
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290 | static uint8_t *add_d6_client_options(uint8_t *ptr)
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291 | {
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292 | return ptr;
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293 | //uint8_t c;
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294 | //int i, end, len;
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295 |
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296 | /* Add a "param req" option with the list of options we'd like to have
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297 | * from stubborn DHCP servers. Pull the data from the struct in common.c.
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298 | * No bounds checking because it goes towards the head of the packet. */
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299 | //...
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300 |
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301 | /* Add -x options if any */
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302 | //...
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303 | }
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304 |
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305 | static int d6_mcast_from_client_config_ifindex(struct d6_packet *packet, uint8_t *end)
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306 | {
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307 | static const uint8_t FF02__1_2[16] = {
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308 | 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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309 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02,
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310 | };
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311 |
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312 | return d6_send_raw_packet(
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313 | packet, (end - (uint8_t*) packet),
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314 | /*src*/ NULL, CLIENT_PORT6,
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315 | /*dst*/ (struct in6_addr*)FF02__1_2, SERVER_PORT6, MAC_BCAST_ADDR,
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316 | client_config.ifindex
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317 | );
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318 | }
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319 |
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320 | /* Milticast a DHCPv6 Solicit packet to the network, with an optionally requested IP.
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321 | *
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322 | * RFC 3315 17.1.1. Creation of Solicit Messages
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323 | *
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324 | * The client MUST include a Client Identifier option to identify itself
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325 | * to the server. The client includes IA options for any IAs to which
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326 | * it wants the server to assign addresses. The client MAY include
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327 | * addresses in the IAs as a hint to the server about addresses for
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328 | * which the client has a preference. ...
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329 | *
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330 | * The client uses IA_NA options to request the assignment of non-
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331 | * temporary addresses and uses IA_TA options to request the assignment
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332 | * of temporary addresses. Either IA_NA or IA_TA options, or a
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333 | * combination of both, can be included in DHCP messages.
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334 | *
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335 | * The client SHOULD include an Option Request option (see section 22.7)
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336 | * to indicate the options the client is interested in receiving. The
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337 | * client MAY additionally include instances of those options that are
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338 | * identified in the Option Request option, with data values as hints to
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339 | * the server about parameter values the client would like to have
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340 | * returned.
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341 | *
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342 | * The client includes a Reconfigure Accept option (see section 22.20)
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343 | * if the client is willing to accept Reconfigure messages from the
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344 | * server.
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345 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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346 | | OPTION_CLIENTID | option-len |
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347 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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348 | . .
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349 | . DUID .
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350 | . (variable length) .
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351 | . .
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352 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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353 |
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354 |
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355 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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356 | | OPTION_IA_NA | option-len |
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357 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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358 | | IAID (4 octets) |
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359 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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360 | | T1 |
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361 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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362 | | T2 |
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363 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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364 | | |
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365 | . IA_NA-options .
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366 | . .
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367 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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368 |
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369 |
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370 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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371 | | OPTION_IAADDR | option-len |
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372 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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373 | | |
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374 | | IPv6 address |
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375 | | |
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376 | | |
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377 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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378 | | preferred-lifetime |
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379 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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380 | | valid-lifetime |
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381 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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382 | . .
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383 | . IAaddr-options .
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384 | . .
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385 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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386 |
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387 |
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388 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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389 | | OPTION_ORO | option-len |
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390 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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391 | | requested-option-code-1 | requested-option-code-2 |
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392 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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393 | | ... |
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394 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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395 |
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396 |
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397 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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398 | | OPTION_RECONF_ACCEPT | 0 |
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399 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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400 | */
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401 | /* NOINLINE: limit stack usage in caller */
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402 | static NOINLINE int send_d6_discover(uint32_t xid, struct in6_addr *requested_ipv6)
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403 | {
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404 | struct d6_packet packet;
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405 | uint8_t *opt_ptr;
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406 | unsigned len;
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407 |
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408 | /* Fill in: msg type, client id */
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409 | opt_ptr = init_d6_packet(&packet, D6_MSG_SOLICIT, xid);
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410 |
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411 | /* Create new IA_NA, optionally with included IAADDR with requested IP */
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412 | free(client6_data.ia_na);
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413 | len = requested_ipv6 ? 2+2+4+4+4 + 2+2+16+4+4 : 2+2+4+4+4;
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414 | client6_data.ia_na = xzalloc(len);
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415 | client6_data.ia_na->code = D6_OPT_IA_NA;
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416 | client6_data.ia_na->len = len - 4;
|
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417 | *(uint32_t*)client6_data.ia_na->data = rand(); /* IAID */
|
---|
418 | if (requested_ipv6) {
|
---|
419 | struct d6_option *iaaddr = (void*)(client6_data.ia_na->data + 4+4+4);
|
---|
420 | iaaddr->code = D6_OPT_IAADDR;
|
---|
421 | iaaddr->len = 16+4+4;
|
---|
422 | memcpy(iaaddr->data, requested_ipv6, 16);
|
---|
423 | }
|
---|
424 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, len);
|
---|
425 |
|
---|
426 | /* Add options:
|
---|
427 | * "param req" option according to -O, options specified with -x
|
---|
428 | */
|
---|
429 | opt_ptr = add_d6_client_options(opt_ptr);
|
---|
430 |
|
---|
431 | bb_error_msg("sending %s", "discover");
|
---|
432 | return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
|
---|
433 | }
|
---|
434 |
|
---|
435 | /* Multicast a DHCPv6 request message
|
---|
436 | *
|
---|
437 | * RFC 3315 18.1.1. Creation and Transmission of Request Messages
|
---|
438 | *
|
---|
439 | * The client uses a Request message to populate IAs with addresses and
|
---|
440 | * obtain other configuration information. The client includes one or
|
---|
441 | * more IA options in the Request message. The server then returns
|
---|
442 | * addresses and other information about the IAs to the client in IA
|
---|
443 | * options in a Reply message.
|
---|
444 | *
|
---|
445 | * The client generates a transaction ID and inserts this value in the
|
---|
446 | * "transaction-id" field.
|
---|
447 | *
|
---|
448 | * The client places the identifier of the destination server in a
|
---|
449 | * Server Identifier option.
|
---|
450 | *
|
---|
451 | * The client MUST include a Client Identifier option to identify itself
|
---|
452 | * to the server. The client adds any other appropriate options,
|
---|
453 | * including one or more IA options (if the client is requesting that
|
---|
454 | * the server assign it some network addresses).
|
---|
455 | *
|
---|
456 | * The client MUST include an Option Request option (see section 22.7)
|
---|
457 | * to indicate the options the client is interested in receiving. The
|
---|
458 | * client MAY include options with data values as hints to the server
|
---|
459 | * about parameter values the client would like to have returned.
|
---|
460 | *
|
---|
461 | * The client includes a Reconfigure Accept option (see section 22.20)
|
---|
462 | * indicating whether or not the client is willing to accept Reconfigure
|
---|
463 | * messages from the server.
|
---|
464 | */
|
---|
465 | /* NOINLINE: limit stack usage in caller */
|
---|
466 | static NOINLINE int send_d6_select(uint32_t xid)
|
---|
467 | {
|
---|
468 | struct d6_packet packet;
|
---|
469 | uint8_t *opt_ptr;
|
---|
470 |
|
---|
471 | /* Fill in: msg type, client id */
|
---|
472 | opt_ptr = init_d6_packet(&packet, D6_MSG_REQUEST, xid);
|
---|
473 |
|
---|
474 | /* server id */
|
---|
475 | opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
|
---|
476 | /* IA NA (contains requested IP) */
|
---|
477 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
|
---|
478 |
|
---|
479 | /* Add options:
|
---|
480 | * "param req" option according to -O, options specified with -x
|
---|
481 | */
|
---|
482 | opt_ptr = add_d6_client_options(opt_ptr);
|
---|
483 |
|
---|
484 | bb_error_msg("sending %s", "select");
|
---|
485 | return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
|
---|
486 | }
|
---|
487 |
|
---|
488 | /* Unicast or broadcast a DHCP renew message
|
---|
489 | *
|
---|
490 | * RFC 3315 18.1.3. Creation and Transmission of Renew Messages
|
---|
491 | *
|
---|
492 | * To extend the valid and preferred lifetimes for the addresses
|
---|
493 | * associated with an IA, the client sends a Renew message to the server
|
---|
494 | * from which the client obtained the addresses in the IA containing an
|
---|
495 | * IA option for the IA. The client includes IA Address options in the
|
---|
496 | * IA option for the addresses associated with the IA. The server
|
---|
497 | * determines new lifetimes for the addresses in the IA according to the
|
---|
498 | * administrative configuration of the server. The server may also add
|
---|
499 | * new addresses to the IA. The server may remove addresses from the IA
|
---|
500 | * by setting the preferred and valid lifetimes of those addresses to
|
---|
501 | * zero.
|
---|
502 | *
|
---|
503 | * The server controls the time at which the client contacts the server
|
---|
504 | * to extend the lifetimes on assigned addresses through the T1 and T2
|
---|
505 | * parameters assigned to an IA.
|
---|
506 | *
|
---|
507 | * At time T1 for an IA, the client initiates a Renew/Reply message
|
---|
508 | * exchange to extend the lifetimes on any addresses in the IA. The
|
---|
509 | * client includes an IA option with all addresses currently assigned to
|
---|
510 | * the IA in its Renew message.
|
---|
511 | *
|
---|
512 | * If T1 or T2 is set to 0 by the server (for an IA_NA) or there are no
|
---|
513 | * T1 or T2 times (for an IA_TA), the client may send a Renew or Rebind
|
---|
514 | * message, respectively, at the client's discretion.
|
---|
515 | *
|
---|
516 | * The client sets the "msg-type" field to RENEW. The client generates
|
---|
517 | * a transaction ID and inserts this value in the "transaction-id"
|
---|
518 | * field.
|
---|
519 | *
|
---|
520 | * The client places the identifier of the destination server in a
|
---|
521 | * Server Identifier option.
|
---|
522 | *
|
---|
523 | * The client MUST include a Client Identifier option to identify itself
|
---|
524 | * to the server. The client adds any appropriate options, including
|
---|
525 | * one or more IA options. The client MUST include the list of
|
---|
526 | * addresses the client currently has associated with the IAs in the
|
---|
527 | * Renew message.
|
---|
528 | *
|
---|
529 | * The client MUST include an Option Request option (see section 22.7)
|
---|
530 | * to indicate the options the client is interested in receiving. The
|
---|
531 | * client MAY include options with data values as hints to the server
|
---|
532 | * about parameter values the client would like to have returned.
|
---|
533 | */
|
---|
534 | /* NOINLINE: limit stack usage in caller */
|
---|
535 | static NOINLINE int send_d6_renew(uint32_t xid, struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
|
---|
536 | {
|
---|
537 | struct d6_packet packet;
|
---|
538 | uint8_t *opt_ptr;
|
---|
539 |
|
---|
540 | /* Fill in: msg type, client id */
|
---|
541 | opt_ptr = init_d6_packet(&packet, DHCPREQUEST, xid);
|
---|
542 |
|
---|
543 | /* server id */
|
---|
544 | opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
|
---|
545 | /* IA NA (contains requested IP) */
|
---|
546 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
|
---|
547 |
|
---|
548 | /* Add options:
|
---|
549 | * "param req" option according to -O, options specified with -x
|
---|
550 | */
|
---|
551 | opt_ptr = add_d6_client_options(opt_ptr);
|
---|
552 |
|
---|
553 | bb_error_msg("sending %s", "renew");
|
---|
554 | if (server_ipv6)
|
---|
555 | return d6_send_kernel_packet(
|
---|
556 | &packet, (opt_ptr - (uint8_t*) &packet),
|
---|
557 | our_cur_ipv6, CLIENT_PORT6,
|
---|
558 | server_ipv6, SERVER_PORT6
|
---|
559 | );
|
---|
560 | return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
|
---|
561 | }
|
---|
562 |
|
---|
563 | /* Unicast a DHCP release message */
|
---|
564 | static int send_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
|
---|
565 | {
|
---|
566 | struct d6_packet packet;
|
---|
567 | uint8_t *opt_ptr;
|
---|
568 |
|
---|
569 | /* Fill in: msg type, client id */
|
---|
570 | opt_ptr = init_d6_packet(&packet, D6_MSG_RELEASE, random_xid());
|
---|
571 | /* server id */
|
---|
572 | opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
|
---|
573 | /* IA NA (contains our current IP) */
|
---|
574 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
|
---|
575 |
|
---|
576 | bb_error_msg("sending %s", "release");
|
---|
577 | return d6_send_kernel_packet(
|
---|
578 | &packet, (opt_ptr - (uint8_t*) &packet),
|
---|
579 | our_cur_ipv6, CLIENT_PORT6,
|
---|
580 | server_ipv6, SERVER_PORT6
|
---|
581 | );
|
---|
582 | }
|
---|
583 |
|
---|
584 | /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
|
---|
585 | /* NOINLINE: limit stack usage in caller */
|
---|
586 | static NOINLINE int d6_recv_raw_packet(struct in6_addr *peer_ipv6
|
---|
587 | UNUSED_PARAM
|
---|
588 | , struct d6_packet *d6_pkt, int fd)
|
---|
589 | {
|
---|
590 | int bytes;
|
---|
591 | struct ip6_udp_d6_packet packet;
|
---|
592 |
|
---|
593 | bytes = safe_read(fd, &packet, sizeof(packet));
|
---|
594 | if (bytes < 0) {
|
---|
595 | log1("packet read error, ignoring");
|
---|
596 | /* NB: possible down interface, etc. Caller should pause. */
|
---|
597 | return bytes; /* returns -1 */
|
---|
598 | }
|
---|
599 |
|
---|
600 | if (bytes < (int) (sizeof(packet.ip6) + sizeof(packet.udp))) {
|
---|
601 | log1("packet is too short, ignoring");
|
---|
602 | return -2;
|
---|
603 | }
|
---|
604 |
|
---|
605 | if (bytes < sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen)) {
|
---|
606 | /* packet is bigger than sizeof(packet), we did partial read */
|
---|
607 | log1("oversized packet, ignoring");
|
---|
608 | return -2;
|
---|
609 | }
|
---|
610 |
|
---|
611 | /* ignore any extra garbage bytes */
|
---|
612 | bytes = sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen);
|
---|
613 |
|
---|
614 | /* make sure its the right packet for us, and that it passes sanity checks */
|
---|
615 | if (packet.ip6.ip6_nxt != IPPROTO_UDP
|
---|
616 | || (packet.ip6.ip6_vfc >> 4) != 6
|
---|
617 | || packet.udp.dest != htons(CLIENT_PORT6)
|
---|
618 | /* || bytes > (int) sizeof(packet) - can't happen */
|
---|
619 | || packet.udp.len != packet.ip6.ip6_plen
|
---|
620 | ) {
|
---|
621 | log1("unrelated/bogus packet, ignoring");
|
---|
622 | return -2;
|
---|
623 | }
|
---|
624 |
|
---|
625 | //How to do this for ipv6?
|
---|
626 | // /* verify UDP checksum. IP header has to be modified for this */
|
---|
627 | // memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
|
---|
628 | // /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
|
---|
629 | // packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
|
---|
630 | // check = packet.udp.check;
|
---|
631 | // packet.udp.check = 0;
|
---|
632 | // if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
|
---|
633 | // log1("packet with bad UDP checksum received, ignoring");
|
---|
634 | // return -2;
|
---|
635 | // }
|
---|
636 |
|
---|
637 | log1("received %s", "a packet");
|
---|
638 | d6_dump_packet(&packet.data);
|
---|
639 |
|
---|
640 | bytes -= sizeof(packet.ip6) + sizeof(packet.udp);
|
---|
641 | memcpy(d6_pkt, &packet.data, bytes);
|
---|
642 | return bytes;
|
---|
643 | }
|
---|
644 |
|
---|
645 |
|
---|
646 | /*** Main ***/
|
---|
647 |
|
---|
648 | static int sockfd = -1;
|
---|
649 |
|
---|
650 | #define LISTEN_NONE 0
|
---|
651 | #define LISTEN_KERNEL 1
|
---|
652 | #define LISTEN_RAW 2
|
---|
653 | static smallint listen_mode;
|
---|
654 |
|
---|
655 | /* initial state: (re)start DHCP negotiation */
|
---|
656 | #define INIT_SELECTING 0
|
---|
657 | /* discover was sent, DHCPOFFER reply received */
|
---|
658 | #define REQUESTING 1
|
---|
659 | /* select/renew was sent, DHCPACK reply received */
|
---|
660 | #define BOUND 2
|
---|
661 | /* half of lease passed, want to renew it by sending unicast renew requests */
|
---|
662 | #define RENEWING 3
|
---|
663 | /* renew requests were not answered, lease is almost over, send broadcast renew */
|
---|
664 | #define REBINDING 4
|
---|
665 | /* manually requested renew (SIGUSR1) */
|
---|
666 | #define RENEW_REQUESTED 5
|
---|
667 | /* release, possibly manually requested (SIGUSR2) */
|
---|
668 | #define RELEASED 6
|
---|
669 | static smallint state;
|
---|
670 |
|
---|
671 | static int d6_raw_socket(int ifindex)
|
---|
672 | {
|
---|
673 | int fd;
|
---|
674 | struct sockaddr_ll sock;
|
---|
675 |
|
---|
676 | /*
|
---|
677 | * Comment:
|
---|
678 | *
|
---|
679 | * I've selected not to see LL header, so BPF doesn't see it, too.
|
---|
680 | * The filter may also pass non-IP and non-ARP packets, but we do
|
---|
681 | * a more complete check when receiving the message in userspace.
|
---|
682 | *
|
---|
683 | * and filter shamelessly stolen from:
|
---|
684 | *
|
---|
685 | * http://www.flamewarmaster.de/software/dhcpclient/
|
---|
686 | *
|
---|
687 | * There are a few other interesting ideas on that page (look under
|
---|
688 | * "Motivation"). Use of netlink events is most interesting. Think
|
---|
689 | * of various network servers listening for events and reconfiguring.
|
---|
690 | * That would obsolete sending HUP signals and/or make use of restarts.
|
---|
691 | *
|
---|
692 | * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
|
---|
693 | * License: GPL v2.
|
---|
694 | *
|
---|
695 | * TODO: make conditional?
|
---|
696 | */
|
---|
697 | #if 0
|
---|
698 | static const struct sock_filter filter_instr[] = {
|
---|
699 | /* load 9th byte (protocol) */
|
---|
700 | BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
|
---|
701 | /* jump to L1 if it is IPPROTO_UDP, else to L4 */
|
---|
702 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
|
---|
703 | /* L1: load halfword from offset 6 (flags and frag offset) */
|
---|
704 | BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
|
---|
705 | /* jump to L4 if any bits in frag offset field are set, else to L2 */
|
---|
706 | BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
|
---|
707 | /* L2: skip IP header (load index reg with header len) */
|
---|
708 | BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
|
---|
709 | /* load udp destination port from halfword[header_len + 2] */
|
---|
710 | BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
|
---|
711 | /* jump to L3 if udp dport is CLIENT_PORT6, else to L4 */
|
---|
712 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
|
---|
713 | /* L3: accept packet */
|
---|
714 | BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
|
---|
715 | /* L4: discard packet */
|
---|
716 | BPF_STMT(BPF_RET|BPF_K, 0),
|
---|
717 | };
|
---|
718 | static const struct sock_fprog filter_prog = {
|
---|
719 | .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
|
---|
720 | /* casting const away: */
|
---|
721 | .filter = (struct sock_filter *) filter_instr,
|
---|
722 | };
|
---|
723 | #endif
|
---|
724 |
|
---|
725 | log1("opening raw socket on ifindex %d", ifindex); //log2?
|
---|
726 |
|
---|
727 | fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
|
---|
728 | log1("got raw socket fd %d", fd); //log2?
|
---|
729 |
|
---|
730 | sock.sll_family = AF_PACKET;
|
---|
731 | sock.sll_protocol = htons(ETH_P_IPV6);
|
---|
732 | sock.sll_ifindex = ifindex;
|
---|
733 | xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
|
---|
734 |
|
---|
735 | #if 0
|
---|
736 | if (CLIENT_PORT6 == 546) {
|
---|
737 | /* Use only if standard port is in use */
|
---|
738 | /* Ignoring error (kernel may lack support for this) */
|
---|
739 | if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
|
---|
740 | sizeof(filter_prog)) >= 0)
|
---|
741 | log1("attached filter to raw socket fd %d", fd); // log?
|
---|
742 | }
|
---|
743 | #endif
|
---|
744 |
|
---|
745 | log1("created raw socket");
|
---|
746 |
|
---|
747 | return fd;
|
---|
748 | }
|
---|
749 |
|
---|
750 | static void change_listen_mode(int new_mode)
|
---|
751 | {
|
---|
752 | log1("entering listen mode: %s",
|
---|
753 | new_mode != LISTEN_NONE
|
---|
754 | ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
|
---|
755 | : "none"
|
---|
756 | );
|
---|
757 |
|
---|
758 | listen_mode = new_mode;
|
---|
759 | if (sockfd >= 0) {
|
---|
760 | close(sockfd);
|
---|
761 | sockfd = -1;
|
---|
762 | }
|
---|
763 | if (new_mode == LISTEN_KERNEL)
|
---|
764 | sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT6, client_config.interface);
|
---|
765 | else if (new_mode != LISTEN_NONE)
|
---|
766 | sockfd = d6_raw_socket(client_config.ifindex);
|
---|
767 | /* else LISTEN_NONE: sockfd stays closed */
|
---|
768 | }
|
---|
769 |
|
---|
770 | /* Called only on SIGUSR1 */
|
---|
771 | static void perform_renew(void)
|
---|
772 | {
|
---|
773 | bb_error_msg("performing DHCP renew");
|
---|
774 | switch (state) {
|
---|
775 | case BOUND:
|
---|
776 | change_listen_mode(LISTEN_KERNEL);
|
---|
777 | case RENEWING:
|
---|
778 | case REBINDING:
|
---|
779 | state = RENEW_REQUESTED;
|
---|
780 | break;
|
---|
781 | case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
|
---|
782 | d6_run_script(NULL, "deconfig");
|
---|
783 | case REQUESTING:
|
---|
784 | case RELEASED:
|
---|
785 | change_listen_mode(LISTEN_RAW);
|
---|
786 | state = INIT_SELECTING;
|
---|
787 | break;
|
---|
788 | case INIT_SELECTING:
|
---|
789 | break;
|
---|
790 | }
|
---|
791 | }
|
---|
792 |
|
---|
793 | static void perform_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
|
---|
794 | {
|
---|
795 | /* send release packet */
|
---|
796 | if (state == BOUND || state == RENEWING || state == REBINDING) {
|
---|
797 | bb_error_msg("unicasting a release");
|
---|
798 | send_d6_release(server_ipv6, our_cur_ipv6); /* unicast */
|
---|
799 | d6_run_script(NULL, "deconfig");
|
---|
800 | }
|
---|
801 | bb_error_msg("entering released state");
|
---|
802 |
|
---|
803 | change_listen_mode(LISTEN_NONE);
|
---|
804 | state = RELEASED;
|
---|
805 | }
|
---|
806 |
|
---|
807 | ///static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
|
---|
808 | ///{
|
---|
809 | /// uint8_t *storage;
|
---|
810 | /// int len = strnlen(str, 255);
|
---|
811 | /// storage = xzalloc(len + extra + OPT_DATA);
|
---|
812 | /// storage[OPT_CODE] = code;
|
---|
813 | /// storage[OPT_LEN] = len + extra;
|
---|
814 | /// memcpy(storage + extra + OPT_DATA, str, len);
|
---|
815 | /// return storage;
|
---|
816 | ///}
|
---|
817 |
|
---|
818 | #if BB_MMU
|
---|
819 | static void client_background(void)
|
---|
820 | {
|
---|
821 | bb_daemonize(0);
|
---|
822 | logmode &= ~LOGMODE_STDIO;
|
---|
823 | /* rewrite pidfile, as our pid is different now */
|
---|
824 | write_pidfile(client_config.pidfile);
|
---|
825 | }
|
---|
826 | #endif
|
---|
827 |
|
---|
828 | //usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
---|
829 | //usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
|
---|
830 | //usage:#else
|
---|
831 | //usage:# define IF_UDHCP_VERBOSE(...)
|
---|
832 | //usage:#endif
|
---|
833 | //usage:#define udhcpc6_trivial_usage
|
---|
834 | //usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
|
---|
835 | //usage: " [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
|
---|
836 | //usage:#define udhcpc6_full_usage "\n"
|
---|
837 | //usage: IF_LONG_OPTS(
|
---|
838 | //usage: "\n -i,--interface IFACE Interface to use (default eth0)"
|
---|
839 | //usage: "\n -p,--pidfile FILE Create pidfile"
|
---|
840 | //usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
|
---|
841 | //usage: "\n -B,--broadcast Request broadcast replies"
|
---|
842 | //usage: "\n -t,--retries N Send up to N discover packets"
|
---|
843 | //usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
|
---|
844 | //usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
|
---|
845 | //usage: "\n -f,--foreground Run in foreground"
|
---|
846 | //usage: USE_FOR_MMU(
|
---|
847 | //usage: "\n -b,--background Background if lease is not obtained"
|
---|
848 | //usage: )
|
---|
849 | //usage: "\n -n,--now Exit if lease is not obtained"
|
---|
850 | //usage: "\n -q,--quit Exit after obtaining lease"
|
---|
851 | //usage: "\n -R,--release Release IP on exit"
|
---|
852 | //usage: "\n -S,--syslog Log to syslog too"
|
---|
853 | //usage: IF_FEATURE_UDHCP_PORT(
|
---|
854 | //usage: "\n -P,--client-port N Use port N (default 546)"
|
---|
855 | //usage: )
|
---|
856 | ////usage: IF_FEATURE_UDHCPC_ARPING(
|
---|
857 | ////usage: "\n -a,--arping Use arping to validate offered address"
|
---|
858 | ////usage: )
|
---|
859 | //usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
|
---|
860 | //usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
|
---|
861 | //usage: "\n -r,--request IP Request this IP address"
|
---|
862 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
|
---|
863 | //usage: "\n Examples of string, numeric, and hex byte opts:"
|
---|
864 | //usage: "\n -x hostname:bbox - option 12"
|
---|
865 | //usage: "\n -x lease:3600 - option 51 (lease time)"
|
---|
866 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
|
---|
867 | //usage: IF_UDHCP_VERBOSE(
|
---|
868 | //usage: "\n -v Verbose"
|
---|
869 | //usage: )
|
---|
870 | //usage: )
|
---|
871 | //usage: IF_NOT_LONG_OPTS(
|
---|
872 | //usage: "\n -i IFACE Interface to use (default eth0)"
|
---|
873 | //usage: "\n -p FILE Create pidfile"
|
---|
874 | //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
|
---|
875 | //usage: "\n -B Request broadcast replies"
|
---|
876 | //usage: "\n -t N Send up to N discover packets"
|
---|
877 | //usage: "\n -T N Pause between packets (default 3 seconds)"
|
---|
878 | //usage: "\n -A N Wait N seconds (default 20) after failure"
|
---|
879 | //usage: "\n -f Run in foreground"
|
---|
880 | //usage: USE_FOR_MMU(
|
---|
881 | //usage: "\n -b Background if lease is not obtained"
|
---|
882 | //usage: )
|
---|
883 | //usage: "\n -n Exit if lease is not obtained"
|
---|
884 | //usage: "\n -q Exit after obtaining lease"
|
---|
885 | //usage: "\n -R Release IP on exit"
|
---|
886 | //usage: "\n -S Log to syslog too"
|
---|
887 | //usage: IF_FEATURE_UDHCP_PORT(
|
---|
888 | //usage: "\n -P N Use port N (default 546)"
|
---|
889 | //usage: )
|
---|
890 | ////usage: IF_FEATURE_UDHCPC_ARPING(
|
---|
891 | ////usage: "\n -a Use arping to validate offered address"
|
---|
892 | ////usage: )
|
---|
893 | //usage: "\n -O OPT Request option OPT from server (cumulative)"
|
---|
894 | //usage: "\n -o Don't request any options (unless -O is given)"
|
---|
895 | //usage: "\n -r IP Request this IP address"
|
---|
896 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
|
---|
897 | //usage: "\n Examples of string, numeric, and hex byte opts:"
|
---|
898 | //usage: "\n -x hostname:bbox - option 12"
|
---|
899 | //usage: "\n -x lease:3600 - option 51 (lease time)"
|
---|
900 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
|
---|
901 | //usage: IF_UDHCP_VERBOSE(
|
---|
902 | //usage: "\n -v Verbose"
|
---|
903 | //usage: )
|
---|
904 | //usage: )
|
---|
905 | //usage: "\nSignals:"
|
---|
906 | //usage: "\n USR1 Renew lease"
|
---|
907 | //usage: "\n USR2 Release lease"
|
---|
908 |
|
---|
909 |
|
---|
910 | int udhcpc6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
911 | int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
|
---|
912 | {
|
---|
913 | const char *str_r;
|
---|
914 | IF_FEATURE_UDHCP_PORT(char *str_P;)
|
---|
915 | void *clientid_mac_ptr;
|
---|
916 | llist_t *list_O = NULL;
|
---|
917 | llist_t *list_x = NULL;
|
---|
918 | int tryagain_timeout = 20;
|
---|
919 | int discover_timeout = 3;
|
---|
920 | int discover_retries = 3;
|
---|
921 | struct in6_addr srv6_buf;
|
---|
922 | struct in6_addr ipv6_buf;
|
---|
923 | struct in6_addr *requested_ipv6;
|
---|
924 | uint32_t xid = 0;
|
---|
925 | int packet_num;
|
---|
926 | int timeout; /* must be signed */
|
---|
927 | unsigned already_waited_sec;
|
---|
928 | unsigned opt;
|
---|
929 | int max_fd;
|
---|
930 | int retval;
|
---|
931 | fd_set rfds;
|
---|
932 |
|
---|
933 | setup_common_bufsiz();
|
---|
934 |
|
---|
935 | /* Default options */
|
---|
936 | IF_FEATURE_UDHCP_PORT(SERVER_PORT6 = 547;)
|
---|
937 | IF_FEATURE_UDHCP_PORT(CLIENT_PORT6 = 546;)
|
---|
938 | client_config.interface = "eth0";
|
---|
939 | client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
|
---|
940 |
|
---|
941 | /* Parse command line */
|
---|
942 | /* O,x: list; -T,-t,-A take numeric param */
|
---|
943 | opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ;
|
---|
944 | IF_LONG_OPTS(applet_long_options = udhcpc6_longopts;)
|
---|
945 | opt = getopt32(argv, "i:np:qRr:s:T:t:SA:O:ox:f"
|
---|
946 | USE_FOR_MMU("b")
|
---|
947 | ///IF_FEATURE_UDHCPC_ARPING("a")
|
---|
948 | IF_FEATURE_UDHCP_PORT("P:")
|
---|
949 | "v"
|
---|
950 | , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
|
---|
951 | , &client_config.script /* s */
|
---|
952 | , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
|
---|
953 | , &list_O
|
---|
954 | , &list_x
|
---|
955 | IF_FEATURE_UDHCP_PORT(, &str_P)
|
---|
956 | IF_UDHCP_VERBOSE(, &dhcp_verbose)
|
---|
957 | );
|
---|
958 | requested_ipv6 = NULL;
|
---|
959 | if (opt & OPT_r) {
|
---|
960 | if (inet_pton(AF_INET6, str_r, &ipv6_buf) <= 0)
|
---|
961 | bb_error_msg_and_die("bad IPv6 address '%s'", str_r);
|
---|
962 | requested_ipv6 = &ipv6_buf;
|
---|
963 | }
|
---|
964 | #if ENABLE_FEATURE_UDHCP_PORT
|
---|
965 | if (opt & OPT_P) {
|
---|
966 | CLIENT_PORT6 = xatou16(str_P);
|
---|
967 | SERVER_PORT6 = CLIENT_PORT6 + 1;
|
---|
968 | }
|
---|
969 | #endif
|
---|
970 | while (list_O) {
|
---|
971 | char *optstr = llist_pop(&list_O);
|
---|
972 | unsigned n = bb_strtou(optstr, NULL, 0);
|
---|
973 | if (errno || n > 254) {
|
---|
974 | n = udhcp_option_idx(optstr);
|
---|
975 | n = dhcp_optflags[n].code;
|
---|
976 | }
|
---|
977 | client_config.opt_mask[n >> 3] |= 1 << (n & 7);
|
---|
978 | }
|
---|
979 | if (!(opt & OPT_o)) {
|
---|
980 | /*
|
---|
981 | unsigned i, n;
|
---|
982 | for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
|
---|
983 | if (dhcp_optflags[i].flags & OPTION_REQ) {
|
---|
984 | client_config.opt_mask[n >> 3] |= 1 << (n & 7);
|
---|
985 | }
|
---|
986 | }
|
---|
987 | */
|
---|
988 | }
|
---|
989 | while (list_x) {
|
---|
990 | char *optstr = llist_pop(&list_x);
|
---|
991 | char *colon = strchr(optstr, ':');
|
---|
992 | if (colon)
|
---|
993 | *colon = ' ';
|
---|
994 | /* now it looks similar to udhcpd's config file line:
|
---|
995 | * "optname optval", using the common routine: */
|
---|
996 | udhcp_str2optset(optstr, &client_config.options);
|
---|
997 | }
|
---|
998 |
|
---|
999 | if (udhcp_read_interface(client_config.interface,
|
---|
1000 | &client_config.ifindex,
|
---|
1001 | NULL,
|
---|
1002 | client_config.client_mac)
|
---|
1003 | ) {
|
---|
1004 | return 1;
|
---|
1005 | }
|
---|
1006 |
|
---|
1007 | /* Create client ID based on mac, set clientid_mac_ptr */
|
---|
1008 | {
|
---|
1009 | struct d6_option *clientid;
|
---|
1010 | clientid = xzalloc(2+2+2+2+6);
|
---|
1011 | clientid->code = D6_OPT_CLIENTID;
|
---|
1012 | clientid->len = 2+2+6;
|
---|
1013 | clientid->data[1] = 3; /* DUID-LL */
|
---|
1014 | clientid->data[3] = 1; /* ethernet */
|
---|
1015 | clientid_mac_ptr = clientid->data + 2+2;
|
---|
1016 | memcpy(clientid_mac_ptr, client_config.client_mac, 6);
|
---|
1017 | client_config.clientid = (void*)clientid;
|
---|
1018 | }
|
---|
1019 |
|
---|
1020 | #if !BB_MMU
|
---|
1021 | /* on NOMMU reexec (i.e., background) early */
|
---|
1022 | if (!(opt & OPT_f)) {
|
---|
1023 | bb_daemonize_or_rexec(0 /* flags */, argv);
|
---|
1024 | logmode = LOGMODE_NONE;
|
---|
1025 | }
|
---|
1026 | #endif
|
---|
1027 | if (opt & OPT_S) {
|
---|
1028 | openlog(applet_name, LOG_PID, LOG_DAEMON);
|
---|
1029 | logmode |= LOGMODE_SYSLOG;
|
---|
1030 | }
|
---|
1031 |
|
---|
1032 | /* Make sure fd 0,1,2 are open */
|
---|
1033 | bb_sanitize_stdio();
|
---|
1034 | /* Equivalent of doing a fflush after every \n */
|
---|
1035 | setlinebuf(stdout);
|
---|
1036 | /* Create pidfile */
|
---|
1037 | write_pidfile(client_config.pidfile);
|
---|
1038 | /* Goes to stdout (unless NOMMU) and possibly syslog */
|
---|
1039 | bb_error_msg("started, v"BB_VER);
|
---|
1040 | /* Set up the signal pipe */
|
---|
1041 | udhcp_sp_setup();
|
---|
1042 | /* We want random_xid to be random... */
|
---|
1043 | srand(monotonic_us());
|
---|
1044 |
|
---|
1045 | state = INIT_SELECTING;
|
---|
1046 | d6_run_script(NULL, "deconfig");
|
---|
1047 | change_listen_mode(LISTEN_RAW);
|
---|
1048 | packet_num = 0;
|
---|
1049 | timeout = 0;
|
---|
1050 | already_waited_sec = 0;
|
---|
1051 |
|
---|
1052 | /* Main event loop. select() waits on signal pipe and possibly
|
---|
1053 | * on sockfd.
|
---|
1054 | * "continue" statements in code below jump to the top of the loop.
|
---|
1055 | */
|
---|
1056 | for (;;) {
|
---|
1057 | struct timeval tv;
|
---|
1058 | struct d6_packet packet;
|
---|
1059 | uint8_t *packet_end;
|
---|
1060 | /* silence "uninitialized!" warning */
|
---|
1061 | unsigned timestamp_before_wait = timestamp_before_wait;
|
---|
1062 |
|
---|
1063 | //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
|
---|
1064 |
|
---|
1065 | /* Was opening raw or udp socket here
|
---|
1066 | * if (listen_mode != LISTEN_NONE && sockfd < 0),
|
---|
1067 | * but on fast network renew responses return faster
|
---|
1068 | * than we open sockets. Thus this code is moved
|
---|
1069 | * to change_listen_mode(). Thus we open listen socket
|
---|
1070 | * BEFORE we send renew request (see "case BOUND:"). */
|
---|
1071 |
|
---|
1072 | max_fd = udhcp_sp_fd_set(&rfds, sockfd);
|
---|
1073 |
|
---|
1074 | tv.tv_sec = timeout - already_waited_sec;
|
---|
1075 | tv.tv_usec = 0;
|
---|
1076 | retval = 0;
|
---|
1077 | /* If we already timed out, fall through with retval = 0, else... */
|
---|
1078 | if ((int)tv.tv_sec > 0) {
|
---|
1079 | log1("waiting on select %u seconds", (int)tv.tv_sec);
|
---|
1080 | timestamp_before_wait = (unsigned)monotonic_sec();
|
---|
1081 | retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
|
---|
1082 | if (retval < 0) {
|
---|
1083 | /* EINTR? A signal was caught, don't panic */
|
---|
1084 | if (errno == EINTR) {
|
---|
1085 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
---|
1086 | continue;
|
---|
1087 | }
|
---|
1088 | /* Else: an error occured, panic! */
|
---|
1089 | bb_perror_msg_and_die("select");
|
---|
1090 | }
|
---|
1091 | }
|
---|
1092 |
|
---|
1093 | /* If timeout dropped to zero, time to become active:
|
---|
1094 | * resend discover/renew/whatever
|
---|
1095 | */
|
---|
1096 | if (retval == 0) {
|
---|
1097 | /* When running on a bridge, the ifindex may have changed
|
---|
1098 | * (e.g. if member interfaces were added/removed
|
---|
1099 | * or if the status of the bridge changed).
|
---|
1100 | * Refresh ifindex and client_mac:
|
---|
1101 | */
|
---|
1102 | if (udhcp_read_interface(client_config.interface,
|
---|
1103 | &client_config.ifindex,
|
---|
1104 | NULL,
|
---|
1105 | client_config.client_mac)
|
---|
1106 | ) {
|
---|
1107 | goto ret0; /* iface is gone? */
|
---|
1108 | }
|
---|
1109 | memcpy(clientid_mac_ptr, client_config.client_mac, 6);
|
---|
1110 |
|
---|
1111 | /* We will restart the wait in any case */
|
---|
1112 | already_waited_sec = 0;
|
---|
1113 |
|
---|
1114 | switch (state) {
|
---|
1115 | case INIT_SELECTING:
|
---|
1116 | if (!discover_retries || packet_num < discover_retries) {
|
---|
1117 | if (packet_num == 0)
|
---|
1118 | xid = random_xid();
|
---|
1119 | /* multicast */
|
---|
1120 | send_d6_discover(xid, requested_ipv6);
|
---|
1121 | timeout = discover_timeout;
|
---|
1122 | packet_num++;
|
---|
1123 | continue;
|
---|
1124 | }
|
---|
1125 | leasefail:
|
---|
1126 | d6_run_script(NULL, "leasefail");
|
---|
1127 | #if BB_MMU /* -b is not supported on NOMMU */
|
---|
1128 | if (opt & OPT_b) { /* background if no lease */
|
---|
1129 | bb_error_msg("no lease, forking to background");
|
---|
1130 | client_background();
|
---|
1131 | /* do not background again! */
|
---|
1132 | opt = ((opt & ~OPT_b) | OPT_f);
|
---|
1133 | } else
|
---|
1134 | #endif
|
---|
1135 | if (opt & OPT_n) { /* abort if no lease */
|
---|
1136 | bb_error_msg("no lease, failing");
|
---|
1137 | retval = 1;
|
---|
1138 | goto ret;
|
---|
1139 | }
|
---|
1140 | /* wait before trying again */
|
---|
1141 | timeout = tryagain_timeout;
|
---|
1142 | packet_num = 0;
|
---|
1143 | continue;
|
---|
1144 | case REQUESTING:
|
---|
1145 | if (!discover_retries || packet_num < discover_retries) {
|
---|
1146 | /* send multicast select packet */
|
---|
1147 | send_d6_select(xid);
|
---|
1148 | timeout = discover_timeout;
|
---|
1149 | packet_num++;
|
---|
1150 | continue;
|
---|
1151 | }
|
---|
1152 | /* Timed out, go back to init state.
|
---|
1153 | * "discover...select...discover..." loops
|
---|
1154 | * were seen in the wild. Treat them similarly
|
---|
1155 | * to "no response to discover" case */
|
---|
1156 | change_listen_mode(LISTEN_RAW);
|
---|
1157 | state = INIT_SELECTING;
|
---|
1158 | goto leasefail;
|
---|
1159 | case BOUND:
|
---|
1160 | /* 1/2 lease passed, enter renewing state */
|
---|
1161 | state = RENEWING;
|
---|
1162 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
1163 | change_listen_mode(LISTEN_KERNEL);
|
---|
1164 | log1("entering renew state");
|
---|
1165 | /* fall right through */
|
---|
1166 | case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
|
---|
1167 | case_RENEW_REQUESTED:
|
---|
1168 | case RENEWING:
|
---|
1169 | if (timeout > 60) {
|
---|
1170 | /* send an unicast renew request */
|
---|
1171 | /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
|
---|
1172 | * a new UDP socket for sending inside send_renew.
|
---|
1173 | * I hazard to guess existing listening socket
|
---|
1174 | * is somehow conflicting with it, but why is it
|
---|
1175 | * not deterministic then?! Strange.
|
---|
1176 | * Anyway, it does recover by eventually failing through
|
---|
1177 | * into INIT_SELECTING state.
|
---|
1178 | */
|
---|
1179 | send_d6_renew(xid, &srv6_buf, requested_ipv6);
|
---|
1180 | timeout >>= 1;
|
---|
1181 | continue;
|
---|
1182 | }
|
---|
1183 | /* Timed out, enter rebinding state */
|
---|
1184 | log1("entering rebinding state");
|
---|
1185 | state = REBINDING;
|
---|
1186 | /* fall right through */
|
---|
1187 | case REBINDING:
|
---|
1188 | /* Switch to bcast receive */
|
---|
1189 | change_listen_mode(LISTEN_RAW);
|
---|
1190 | /* Lease is *really* about to run out,
|
---|
1191 | * try to find DHCP server using broadcast */
|
---|
1192 | if (timeout > 0) {
|
---|
1193 | /* send a broadcast renew request */
|
---|
1194 | send_d6_renew(xid, /*server_ipv6:*/ NULL, requested_ipv6);
|
---|
1195 | timeout >>= 1;
|
---|
1196 | continue;
|
---|
1197 | }
|
---|
1198 | /* Timed out, enter init state */
|
---|
1199 | bb_error_msg("lease lost, entering init state");
|
---|
1200 | d6_run_script(NULL, "deconfig");
|
---|
1201 | state = INIT_SELECTING;
|
---|
1202 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
1203 | /*timeout = 0; - already is */
|
---|
1204 | packet_num = 0;
|
---|
1205 | continue;
|
---|
1206 | /* case RELEASED: */
|
---|
1207 | }
|
---|
1208 | /* yah, I know, *you* say it would never happen */
|
---|
1209 | timeout = INT_MAX;
|
---|
1210 | continue; /* back to main loop */
|
---|
1211 | } /* if select timed out */
|
---|
1212 |
|
---|
1213 | /* select() didn't timeout, something happened */
|
---|
1214 |
|
---|
1215 | /* Is it a signal? */
|
---|
1216 | /* note: udhcp_sp_read checks FD_ISSET before reading */
|
---|
1217 | switch (udhcp_sp_read(&rfds)) {
|
---|
1218 | case SIGUSR1:
|
---|
1219 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
1220 | already_waited_sec = 0;
|
---|
1221 | perform_renew();
|
---|
1222 | if (state == RENEW_REQUESTED) {
|
---|
1223 | /* We might be either on the same network
|
---|
1224 | * (in which case renew might work),
|
---|
1225 | * or we might be on a completely different one
|
---|
1226 | * (in which case renew won't ever succeed).
|
---|
1227 | * For the second case, must make sure timeout
|
---|
1228 | * is not too big, or else we can send
|
---|
1229 | * futile renew requests for hours.
|
---|
1230 | * (Ab)use -A TIMEOUT value (usually 20 sec)
|
---|
1231 | * as a cap on the timeout.
|
---|
1232 | */
|
---|
1233 | if (timeout > tryagain_timeout)
|
---|
1234 | timeout = tryagain_timeout;
|
---|
1235 | goto case_RENEW_REQUESTED;
|
---|
1236 | }
|
---|
1237 | /* Start things over */
|
---|
1238 | packet_num = 0;
|
---|
1239 | /* Kill any timeouts, user wants this to hurry along */
|
---|
1240 | timeout = 0;
|
---|
1241 | continue;
|
---|
1242 | case SIGUSR2:
|
---|
1243 | perform_d6_release(&srv6_buf, requested_ipv6);
|
---|
1244 | timeout = INT_MAX;
|
---|
1245 | continue;
|
---|
1246 | case SIGTERM:
|
---|
1247 | bb_error_msg("received %s", "SIGTERM");
|
---|
1248 | goto ret0;
|
---|
1249 | }
|
---|
1250 |
|
---|
1251 | /* Is it a packet? */
|
---|
1252 | if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
|
---|
1253 | continue; /* no */
|
---|
1254 |
|
---|
1255 | {
|
---|
1256 | int len;
|
---|
1257 |
|
---|
1258 | /* A packet is ready, read it */
|
---|
1259 | if (listen_mode == LISTEN_KERNEL)
|
---|
1260 | len = d6_recv_kernel_packet(&srv6_buf, &packet, sockfd);
|
---|
1261 | else
|
---|
1262 | len = d6_recv_raw_packet(&srv6_buf, &packet, sockfd);
|
---|
1263 | if (len == -1) {
|
---|
1264 | /* Error is severe, reopen socket */
|
---|
1265 | bb_error_msg("read error: %s, reopening socket", strerror(errno));
|
---|
1266 | sleep(discover_timeout); /* 3 seconds by default */
|
---|
1267 | change_listen_mode(listen_mode); /* just close and reopen */
|
---|
1268 | }
|
---|
1269 | /* If this packet will turn out to be unrelated/bogus,
|
---|
1270 | * we will go back and wait for next one.
|
---|
1271 | * Be sure timeout is properly decreased. */
|
---|
1272 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
---|
1273 | if (len < 0)
|
---|
1274 | continue;
|
---|
1275 | packet_end = (uint8_t*)&packet + len;
|
---|
1276 | }
|
---|
1277 |
|
---|
1278 | if ((packet.d6_xid32 & htonl(0x00ffffff)) != xid) {
|
---|
1279 | log1("xid %x (our is %x), ignoring packet",
|
---|
1280 | (unsigned)(packet.d6_xid32 & htonl(0x00ffffff)), (unsigned)xid);
|
---|
1281 | continue;
|
---|
1282 | }
|
---|
1283 |
|
---|
1284 | switch (state) {
|
---|
1285 | case INIT_SELECTING:
|
---|
1286 | if (packet.d6_msg_type == D6_MSG_ADVERTISE)
|
---|
1287 | goto type_is_ok;
|
---|
1288 | /* DHCPv6 has "Rapid Commit", when instead of Advertise,
|
---|
1289 | * server sends Reply right away.
|
---|
1290 | * Fall through to check for this case.
|
---|
1291 | */
|
---|
1292 | case REQUESTING:
|
---|
1293 | case RENEWING:
|
---|
1294 | case RENEW_REQUESTED:
|
---|
1295 | case REBINDING:
|
---|
1296 | if (packet.d6_msg_type == D6_MSG_REPLY) {
|
---|
1297 | uint32_t lease_seconds;
|
---|
1298 | struct d6_option *option, *iaaddr;
|
---|
1299 | type_is_ok:
|
---|
1300 | option = d6_find_option(packet.d6_options, packet_end, D6_OPT_STATUS_CODE);
|
---|
1301 | if (option && option->data[4] != 0) {
|
---|
1302 | /* return to init state */
|
---|
1303 | bb_error_msg("received DHCP NAK (%u)", option->data[4]);
|
---|
1304 | d6_run_script(&packet, "nak");
|
---|
1305 | if (state != REQUESTING)
|
---|
1306 | d6_run_script(NULL, "deconfig");
|
---|
1307 | change_listen_mode(LISTEN_RAW);
|
---|
1308 | sleep(3); /* avoid excessive network traffic */
|
---|
1309 | state = INIT_SELECTING;
|
---|
1310 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
1311 | requested_ipv6 = NULL;
|
---|
1312 | timeout = 0;
|
---|
1313 | packet_num = 0;
|
---|
1314 | already_waited_sec = 0;
|
---|
1315 | continue;
|
---|
1316 | }
|
---|
1317 | option = d6_copy_option(packet.d6_options, packet_end, D6_OPT_SERVERID);
|
---|
1318 | if (!option) {
|
---|
1319 | bb_error_msg("no server ID, ignoring packet");
|
---|
1320 | continue;
|
---|
1321 | /* still selecting - this server looks bad */
|
---|
1322 | }
|
---|
1323 | //Note: we do not bother comparing server IDs in Advertise and Reply msgs.
|
---|
1324 | //server_id variable is used solely for creation of proper server_id option
|
---|
1325 | //in outgoing packets. (why DHCPv6 even introduced it is a mystery).
|
---|
1326 | free(client6_data.server_id);
|
---|
1327 | client6_data.server_id = option;
|
---|
1328 | if (packet.d6_msg_type == D6_MSG_ADVERTISE) {
|
---|
1329 | /* enter requesting state */
|
---|
1330 | state = REQUESTING;
|
---|
1331 | timeout = 0;
|
---|
1332 | packet_num = 0;
|
---|
1333 | already_waited_sec = 0;
|
---|
1334 | continue;
|
---|
1335 | }
|
---|
1336 | /* It's a D6_MSG_REPLY */
|
---|
1337 | /*
|
---|
1338 | * RFC 3315 18.1.8. Receipt of Reply Messages
|
---|
1339 | *
|
---|
1340 | * Upon the receipt of a valid Reply message in response to a Solicit
|
---|
1341 | * (with a Rapid Commit option), Request, Confirm, Renew, Rebind or
|
---|
1342 | * Information-request message, the client extracts the configuration
|
---|
1343 | * information contained in the Reply. The client MAY choose to report
|
---|
1344 | * any status code or message from the status code option in the Reply
|
---|
1345 | * message.
|
---|
1346 | *
|
---|
1347 | * The client SHOULD perform duplicate address detection [17] on each of
|
---|
1348 | * the addresses in any IAs it receives in the Reply message before
|
---|
1349 | * using that address for traffic. If any of the addresses are found to
|
---|
1350 | * be in use on the link, the client sends a Decline message to the
|
---|
1351 | * server as described in section 18.1.7.
|
---|
1352 | *
|
---|
1353 | * If the Reply was received in response to a Solicit (with a Rapid
|
---|
1354 | * Commit option), Request, Renew or Rebind message, the client updates
|
---|
1355 | * the information it has recorded about IAs from the IA options
|
---|
1356 | * contained in the Reply message:
|
---|
1357 | *
|
---|
1358 | * - Record T1 and T2 times.
|
---|
1359 | *
|
---|
1360 | * - Add any new addresses in the IA option to the IA as recorded by
|
---|
1361 | * the client.
|
---|
1362 | *
|
---|
1363 | * - Update lifetimes for any addresses in the IA option that the
|
---|
1364 | * client already has recorded in the IA.
|
---|
1365 | *
|
---|
1366 | * - Discard any addresses from the IA, as recorded by the client, that
|
---|
1367 | * have a valid lifetime of 0 in the IA Address option.
|
---|
1368 | *
|
---|
1369 | * - Leave unchanged any information about addresses the client has
|
---|
1370 | * recorded in the IA but that were not included in the IA from the
|
---|
1371 | * server.
|
---|
1372 | *
|
---|
1373 | * Management of the specific configuration information is detailed in
|
---|
1374 | * the definition of each option in section 22.
|
---|
1375 | *
|
---|
1376 | * If the client receives a Reply message with a Status Code containing
|
---|
1377 | * UnspecFail, the server is indicating that it was unable to process
|
---|
1378 | * the message due to an unspecified failure condition. If the client
|
---|
1379 | * retransmits the original message to the same server to retry the
|
---|
1380 | * desired operation, the client MUST limit the rate at which it
|
---|
1381 | * retransmits the message and limit the duration of the time during
|
---|
1382 | * which it retransmits the message.
|
---|
1383 | *
|
---|
1384 | * When the client receives a Reply message with a Status Code option
|
---|
1385 | * with the value UseMulticast, the client records the receipt of the
|
---|
1386 | * message and sends subsequent messages to the server through the
|
---|
1387 | * interface on which the message was received using multicast. The
|
---|
1388 | * client resends the original message using multicast.
|
---|
1389 | *
|
---|
1390 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1391 | * | OPTION_IA_NA | option-len |
|
---|
1392 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1393 | * | IAID (4 octets) |
|
---|
1394 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1395 | * | T1 |
|
---|
1396 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1397 | * | T2 |
|
---|
1398 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1399 | * | |
|
---|
1400 | * . IA_NA-options .
|
---|
1401 | * . .
|
---|
1402 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1403 | *
|
---|
1404 | *
|
---|
1405 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1406 | * | OPTION_IAADDR | option-len |
|
---|
1407 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1408 | * | |
|
---|
1409 | * | IPv6 address |
|
---|
1410 | * | |
|
---|
1411 | * | |
|
---|
1412 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1413 | * | preferred-lifetime |
|
---|
1414 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1415 | * | valid-lifetime |
|
---|
1416 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1417 | * . .
|
---|
1418 | * . IAaddr-options .
|
---|
1419 | * . .
|
---|
1420 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
1421 | */
|
---|
1422 | free(client6_data.ia_na);
|
---|
1423 | client6_data.ia_na = d6_copy_option(packet.d6_options, packet_end, D6_OPT_IA_NA);
|
---|
1424 | if (!client6_data.ia_na) {
|
---|
1425 | bb_error_msg("no %s option, ignoring packet", "IA_NA");
|
---|
1426 | continue;
|
---|
1427 | }
|
---|
1428 | if (client6_data.ia_na->len < (4 + 4 + 4) + (2 + 2 + 16 + 4 + 4)) {
|
---|
1429 | bb_error_msg("IA_NA option is too short:%d bytes", client6_data.ia_na->len);
|
---|
1430 | continue;
|
---|
1431 | }
|
---|
1432 | iaaddr = d6_find_option(client6_data.ia_na->data + 4 + 4 + 4,
|
---|
1433 | client6_data.ia_na->data + client6_data.ia_na->len,
|
---|
1434 | D6_OPT_IAADDR
|
---|
1435 | );
|
---|
1436 | if (!iaaddr) {
|
---|
1437 | bb_error_msg("no %s option, ignoring packet", "IAADDR");
|
---|
1438 | continue;
|
---|
1439 | }
|
---|
1440 | if (iaaddr->len < (16 + 4 + 4)) {
|
---|
1441 | bb_error_msg("IAADDR option is too short:%d bytes", iaaddr->len);
|
---|
1442 | continue;
|
---|
1443 | }
|
---|
1444 | /* Note: the address is sufficiently aligned for cast:
|
---|
1445 | * we _copied_ IA-NA, and copy is always well-aligned.
|
---|
1446 | */
|
---|
1447 | requested_ipv6 = (struct in6_addr*) iaaddr->data;
|
---|
1448 | move_from_unaligned32(lease_seconds, iaaddr->data + 16 + 4);
|
---|
1449 | lease_seconds = ntohl(lease_seconds);
|
---|
1450 | /* paranoia: must not be too small and not prone to overflows */
|
---|
1451 | if (lease_seconds < 0x10)
|
---|
1452 | lease_seconds = 0x10;
|
---|
1453 | /// TODO: check for 0 lease time?
|
---|
1454 | if (lease_seconds >= 0x10000000)
|
---|
1455 | lease_seconds = 0x0fffffff;
|
---|
1456 | /* enter bound state */
|
---|
1457 | timeout = lease_seconds / 2;
|
---|
1458 | bb_error_msg("lease obtained, lease time %u",
|
---|
1459 | /*inet_ntoa(temp_addr),*/ (unsigned)lease_seconds);
|
---|
1460 | d6_run_script(&packet, state == REQUESTING ? "bound" : "renew");
|
---|
1461 |
|
---|
1462 | state = BOUND;
|
---|
1463 | change_listen_mode(LISTEN_NONE);
|
---|
1464 | if (opt & OPT_q) { /* quit after lease */
|
---|
1465 | goto ret0;
|
---|
1466 | }
|
---|
1467 | /* future renew failures should not exit (JM) */
|
---|
1468 | opt &= ~OPT_n;
|
---|
1469 | #if BB_MMU /* NOMMU case backgrounded earlier */
|
---|
1470 | if (!(opt & OPT_f)) {
|
---|
1471 | client_background();
|
---|
1472 | /* do not background again! */
|
---|
1473 | opt = ((opt & ~OPT_b) | OPT_f);
|
---|
1474 | }
|
---|
1475 | #endif
|
---|
1476 | already_waited_sec = 0;
|
---|
1477 | continue; /* back to main loop */
|
---|
1478 | }
|
---|
1479 | continue;
|
---|
1480 | /* case BOUND: - ignore all packets */
|
---|
1481 | /* case RELEASED: - ignore all packets */
|
---|
1482 | }
|
---|
1483 | /* back to main loop */
|
---|
1484 | } /* for (;;) - main loop ends */
|
---|
1485 |
|
---|
1486 | ret0:
|
---|
1487 | if (opt & OPT_R) /* release on quit */
|
---|
1488 | perform_d6_release(&srv6_buf, requested_ipv6);
|
---|
1489 | retval = 0;
|
---|
1490 | ret:
|
---|
1491 | /*if (client_config.pidfile) - remove_pidfile has its own check */
|
---|
1492 | remove_pidfile(client_config.pidfile);
|
---|
1493 | return retval;
|
---|
1494 | }
|
---|