1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * udhcp client
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4 | *
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5 | * Russ Dill <Russ.Dill@asu.edu> July 2001
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6 | *
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7 | * This program is free software; you can redistribute it and/or modify
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8 | * it under the terms of the GNU General Public License as published by
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9 | * the Free Software Foundation; either version 2 of the License, or
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10 | * (at your option) any later version.
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11 | *
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12 | * This program is distributed in the hope that it will be useful,
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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15 | * GNU General Public License for more details.
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16 | *
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17 | * You should have received a copy of the GNU General Public License
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18 | * along with this program; if not, write to the Free Software
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19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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20 | */
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21 | #include <syslog.h>
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22 | /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
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23 | #define WANT_PIDFILE 1
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24 | #include "common.h"
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25 | #include "dhcpd.h"
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26 | #include "dhcpc.h"
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27 |
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28 | #include <asm/types.h>
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29 | #if (defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1) || defined(_NEWLIB_VERSION)
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30 | # include <netpacket/packet.h>
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31 | # include <net/ethernet.h>
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32 | #else
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33 | # include <linux/if_packet.h>
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34 | # include <linux/if_ether.h>
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35 | #endif
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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 | /*** Script execution code ***/
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42 |
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43 | /* get a rough idea of how long an option will be (rounding up...) */
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44 | static const uint8_t len_of_option_as_string[] = {
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45 | [OPTION_IP ] = sizeof("255.255.255.255 "),
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46 | [OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
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47 | [OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
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48 | [OPTION_STRING ] = 1,
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49 | #if ENABLE_FEATURE_UDHCP_RFC3397
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50 | [OPTION_DNS_STRING ] = 1, /* unused */
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51 | /* Hmmm, this severely overestimates size if SIP_SERVERS option
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52 | * is in domain name form: N-byte option in binary form
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53 | * mallocs ~16*N bytes. But it is freed almost at once.
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54 | */
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55 | [OPTION_SIP_SERVERS ] = sizeof("255.255.255.255 "),
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56 | #endif
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57 | // [OPTION_BOOLEAN ] = sizeof("yes "),
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58 | [OPTION_U8 ] = sizeof("255 "),
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59 | [OPTION_U16 ] = sizeof("65535 "),
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60 | // [OPTION_S16 ] = sizeof("-32768 "),
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61 | [OPTION_U32 ] = sizeof("4294967295 "),
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62 | [OPTION_S32 ] = sizeof("-2147483684 "),
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63 | };
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64 |
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65 | /* note: ip is a pointer to an IP in network order, possibly misaliged */
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66 | static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
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67 | {
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68 | return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
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69 | }
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70 |
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71 | /* really simple implementation, just count the bits */
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72 | static int mton(uint32_t mask)
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73 | {
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74 | int i = 0;
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75 | mask = ntohl(mask); /* 111110000-like bit pattern */
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76 | while (mask) {
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77 | i++;
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78 | mask <<= 1;
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79 | }
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80 | return i;
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81 | }
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82 |
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83 | /* Create "opt_name=opt_value" string */
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84 | static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
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85 | {
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86 | unsigned upper_length;
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87 | int len, type, optlen;
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88 | char *dest, *ret;
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89 |
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90 | /* option points to OPT_DATA, need to go back and get OPT_LEN */
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91 | len = option[OPT_LEN - OPT_DATA];
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92 |
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93 | type = optflag->flags & OPTION_TYPE_MASK;
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94 | optlen = dhcp_option_lengths[type];
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95 | upper_length = len_of_option_as_string[type] * ((unsigned)len / (unsigned)optlen);
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96 |
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97 | dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
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98 | dest += sprintf(ret, "%s=", opt_name);
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99 |
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100 | while (len >= optlen) {
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101 | unsigned ip_ofs = 0;
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102 |
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103 | switch (type) {
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104 | case OPTION_IP_PAIR:
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105 | dest += sprint_nip(dest, "", option);
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106 | *dest++ = '/';
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107 | ip_ofs = 4;
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108 | /* fall through */
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109 | case OPTION_IP:
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110 | dest += sprint_nip(dest, "", option + ip_ofs);
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111 | break;
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112 | // case OPTION_BOOLEAN:
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113 | // dest += sprintf(dest, *option ? "yes" : "no");
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114 | // break;
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115 | case OPTION_U8:
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116 | dest += sprintf(dest, "%u", *option);
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117 | break;
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118 | // case OPTION_S16:
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119 | case OPTION_U16: {
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120 | uint16_t val_u16;
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121 | move_from_unaligned16(val_u16, option);
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122 | dest += sprintf(dest, "%u", ntohs(val_u16));
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123 | break;
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124 | }
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125 | case OPTION_S32:
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126 | case OPTION_U32: {
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127 | uint32_t val_u32;
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128 | move_from_unaligned32(val_u32, option);
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129 | dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32));
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130 | break;
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131 | }
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132 | case OPTION_STRING:
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133 | memcpy(dest, option, len);
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134 | dest[len] = '\0';
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135 | return ret; /* Short circuit this case */
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136 | case OPTION_STATIC_ROUTES: {
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137 | /* Option binary format:
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138 | * mask [one byte, 0..32]
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139 | * ip [big endian, 0..4 bytes depending on mask]
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140 | * router [big endian, 4 bytes]
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141 | * may be repeated
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142 | *
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143 | * We convert it to a string "IP/MASK ROUTER IP2/MASK2 ROUTER2"
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144 | */
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145 | const char *pfx = "";
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146 |
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147 | while (len >= 1 + 4) { /* mask + 0-byte ip + router */
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148 | uint32_t nip;
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149 | uint8_t *p;
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150 | unsigned mask;
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151 | int bytes;
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152 |
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153 | mask = *option++;
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154 | if (mask > 32)
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155 | break;
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156 | len--;
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157 |
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158 | nip = 0;
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159 | p = (void*) &nip;
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160 | bytes = (mask + 7) / 8; /* 0 -> 0, 1..8 -> 1, 9..16 -> 2 etc */
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161 | while (--bytes >= 0) {
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162 | *p++ = *option++;
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163 | len--;
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164 | }
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165 | if (len < 4)
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166 | break;
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167 |
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168 | /* print ip/mask */
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169 | dest += sprint_nip(dest, pfx, (void*) &nip);
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170 | pfx = " ";
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171 | dest += sprintf(dest, "/%u ", mask);
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172 | /* print router */
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173 | dest += sprint_nip(dest, "", option);
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174 | option += 4;
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175 | len -= 4;
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176 | }
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177 |
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178 | return ret;
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179 | }
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180 | #if ENABLE_FEATURE_UDHCP_RFC3397
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181 | case OPTION_DNS_STRING:
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182 | /* unpack option into dest; use ret for prefix (i.e., "optname=") */
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183 | dest = dname_dec(option, len, ret);
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184 | if (dest) {
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185 | free(ret);
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186 | return dest;
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187 | }
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188 | /* error. return "optname=" string */
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189 | return ret;
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190 | case OPTION_SIP_SERVERS:
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191 | /* Option binary format:
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192 | * type: byte
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193 | * type=0: domain names, dns-compressed
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194 | * type=1: IP addrs
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195 | */
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196 | option++;
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197 | len--;
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198 | if (option[-1] == 0) {
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199 | dest = dname_dec(option, len, ret);
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200 | if (dest) {
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201 | free(ret);
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202 | return dest;
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203 | }
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204 | } else
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205 | if (option[-1] == 1) {
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206 | const char *pfx = "";
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207 | while (1) {
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208 | len -= 4;
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209 | if (len < 0)
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210 | break;
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211 | dest += sprint_nip(dest, pfx, option);
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212 | pfx = " ";
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213 | option += 4;
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214 | }
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215 | }
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216 | return ret;
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217 | #endif
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218 | } /* switch */
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219 | option += optlen;
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220 | len -= optlen;
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221 | // TODO: it can be a list only if (optflag->flags & OPTION_LIST).
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222 | // Should we bail out/warn if we see multi-ip option which is
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223 | // not allowed to be such (for example, DHCP_BROADCAST)? -
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224 | if (len <= 0 /* || !(optflag->flags & OPTION_LIST) */)
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225 | break;
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226 | *dest++ = ' ';
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227 | *dest = '\0';
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228 | }
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229 | return ret;
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230 | }
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231 |
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232 | /* put all the parameters into the environment */
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233 | static char **fill_envp(struct dhcp_packet *packet)
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234 | {
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235 | int envc;
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236 | int i;
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237 | char **envp, **curr;
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238 | const char *opt_name;
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239 | uint8_t *temp;
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240 | uint8_t overload = 0;
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241 |
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242 | /* We need 6 elements for:
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243 | * "interface=IFACE"
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244 | * "ip=N.N.N.N" from packet->yiaddr
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245 | * "siaddr=IP" from packet->siaddr_nip (unless 0)
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246 | * "boot_file=FILE" from packet->file (unless overloaded)
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247 | * "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
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248 | * terminating NULL
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249 | */
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250 | envc = 6;
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251 | /* +1 element for each option, +2 for subnet option: */
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252 | if (packet) {
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253 | for (i = 0; dhcp_optflags[i].code; i++) {
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254 | if (udhcp_get_option(packet, dhcp_optflags[i].code)) {
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255 | if (dhcp_optflags[i].code == DHCP_SUBNET)
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256 | envc++; /* for mton */
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257 | envc++;
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258 | }
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259 | }
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260 | temp = udhcp_get_option(packet, DHCP_OPTION_OVERLOAD);
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261 | if (temp)
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262 | overload = *temp;
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263 | }
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264 | curr = envp = xzalloc(sizeof(char *) * envc);
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265 |
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266 | *curr = xasprintf("interface=%s", client_config.interface);
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267 | putenv(*curr++);
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268 |
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269 | if (!packet)
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270 | return envp;
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271 |
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272 | *curr = xmalloc(sizeof("ip=255.255.255.255"));
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273 | sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
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274 | putenv(*curr++);
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275 |
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276 | opt_name = dhcp_option_strings;
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277 | i = 0;
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278 | while (*opt_name) {
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279 | temp = udhcp_get_option(packet, dhcp_optflags[i].code);
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280 | if (!temp)
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281 | goto next;
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282 | *curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
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283 | putenv(*curr++);
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284 | if (dhcp_optflags[i].code == DHCP_SUBNET) {
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285 | /* Subnet option: make things like "$ip/$mask" possible */
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286 | uint32_t subnet;
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287 | move_from_unaligned32(subnet, temp);
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288 | *curr = xasprintf("mask=%d", mton(subnet));
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289 | putenv(*curr++);
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290 | }
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291 | next:
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292 | opt_name += strlen(opt_name) + 1;
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293 | i++;
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294 | }
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295 | if (packet->siaddr_nip) {
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296 | *curr = xmalloc(sizeof("siaddr=255.255.255.255"));
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297 | sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
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298 | putenv(*curr++);
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299 | }
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300 | if (!(overload & FILE_FIELD) && packet->file[0]) {
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301 | /* watch out for invalid packets */
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302 | *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
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303 | putenv(*curr++);
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304 | }
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305 | if (!(overload & SNAME_FIELD) && packet->sname[0]) {
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306 | /* watch out for invalid packets */
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307 | *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
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308 | putenv(*curr++);
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309 | }
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310 | return envp;
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311 | }
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312 |
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313 | /* Call a script with a par file and env vars */
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314 | static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
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315 | {
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316 | char **envp, **curr;
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317 | char *argv[3];
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318 |
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319 | if (client_config.script == NULL)
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320 | return;
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321 |
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322 | envp = fill_envp(packet);
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323 |
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324 | /* call script */
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325 | log1("Executing %s %s", client_config.script, name);
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326 | argv[0] = (char*) client_config.script;
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327 | argv[1] = (char*) name;
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328 | argv[2] = NULL;
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329 | spawn_and_wait(argv);
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330 |
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331 | for (curr = envp; *curr; curr++) {
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332 | log2(" %s", *curr);
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333 | bb_unsetenv_and_free(*curr);
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334 | }
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335 | free(envp);
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336 | }
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337 |
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338 |
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339 | /*** Sending/receiving packets ***/
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340 |
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341 | static ALWAYS_INLINE uint32_t random_xid(void)
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342 | {
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343 | return rand();
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344 | }
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345 |
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346 | /* Initialize the packet with the proper defaults */
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347 | static void init_packet(struct dhcp_packet *packet, char type)
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348 | {
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349 | /* Fill in: op, htype, hlen, cookie fields; message type option: */
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350 | udhcp_init_header(packet, type);
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351 |
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352 | packet->xid = random_xid();
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353 |
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354 | memcpy(packet->chaddr, client_config.client_mac, 6);
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355 | if (client_config.clientid)
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356 | udhcp_add_binary_option(packet, client_config.clientid);
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357 | }
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358 |
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359 | static void add_client_options(struct dhcp_packet *packet)
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360 | {
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361 | uint8_t c;
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362 | int i, end, len;
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363 |
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364 | udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE));
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365 |
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366 | /* Add a "param req" option with the list of options we'd like to have
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367 | * from stubborn DHCP servers. Pull the data from the struct in common.c.
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368 | * No bounds checking because it goes towards the head of the packet. */
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369 | end = udhcp_end_option(packet->options);
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370 | len = 0;
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371 | for (i = 0; (c = dhcp_optflags[i].code) != 0; i++) {
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372 | if (( (dhcp_optflags[i].flags & OPTION_REQ)
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373 | && !client_config.no_default_options
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374 | )
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375 | || (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
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376 | ) {
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377 | packet->options[end + OPT_DATA + len] = c;
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378 | len++;
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379 | }
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380 | }
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381 | if (len) {
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382 | packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
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383 | packet->options[end + OPT_LEN] = len;
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384 | packet->options[end + OPT_DATA + len] = DHCP_END;
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385 | }
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386 |
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387 | if (client_config.vendorclass)
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388 | udhcp_add_binary_option(packet, client_config.vendorclass);
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389 | if (client_config.hostname)
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390 | udhcp_add_binary_option(packet, client_config.hostname);
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391 | if (client_config.fqdn)
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392 | udhcp_add_binary_option(packet, client_config.fqdn);
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393 |
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394 | /* Add -x options if any */
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395 | {
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396 | struct option_set *curr = client_config.options;
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397 | while (curr) {
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398 | udhcp_add_binary_option(packet, curr->data);
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399 | curr = curr->next;
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400 | }
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401 | // if (client_config.sname)
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402 | // strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1);
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403 | // if (client_config.boot_file)
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404 | // strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
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405 | }
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406 | }
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407 |
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408 | /* RFC 2131
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409 | * 4.4.4 Use of broadcast and unicast
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410 | *
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411 | * The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
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412 | * messages, unless the client knows the address of a DHCP server.
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413 | * The client unicasts DHCPRELEASE messages to the server. Because
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414 | * the client is declining the use of the IP address supplied by the server,
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415 | * the client broadcasts DHCPDECLINE messages.
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416 | *
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417 | * When the DHCP client knows the address of a DHCP server, in either
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418 | * INIT or REBOOTING state, the client may use that address
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419 | * in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
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420 | * The client may also use unicast to send DHCPINFORM messages
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421 | * to a known DHCP server. If the client receives no response to DHCP
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422 | * messages sent to the IP address of a known DHCP server, the DHCP
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423 | * client reverts to using the IP broadcast address.
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424 | */
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425 |
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426 | static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
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427 | {
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428 | return udhcp_send_raw_packet(packet,
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429 | /*src*/ INADDR_ANY, CLIENT_PORT,
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430 | /*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
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431 | client_config.ifindex);
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432 | }
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433 |
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434 | /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
|
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435 | /* NOINLINE: limit stack usage in caller */
|
---|
436 | static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
|
---|
437 | {
|
---|
438 | struct dhcp_packet packet;
|
---|
439 |
|
---|
440 | /* Fill in: op, htype, hlen, cookie, chaddr fields,
|
---|
441 | * random xid field (we override it below),
|
---|
442 | * client-id option (unless -C), message type option:
|
---|
443 | */
|
---|
444 | init_packet(&packet, DHCPDISCOVER);
|
---|
445 |
|
---|
446 | packet.xid = xid;
|
---|
447 | if (requested)
|
---|
448 | udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
|
---|
449 |
|
---|
450 | /* Add options: maxsize,
|
---|
451 | * optionally: hostname, fqdn, vendorclass,
|
---|
452 | * "param req" option according to -O, options specified with -x
|
---|
453 | */
|
---|
454 | add_client_options(&packet);
|
---|
455 |
|
---|
456 | bb_info_msg("Sending discover...");
|
---|
457 | return raw_bcast_from_client_config_ifindex(&packet);
|
---|
458 | }
|
---|
459 |
|
---|
460 | /* Broadcast a DHCP request message */
|
---|
461 | /* RFC 2131 3.1 paragraph 3:
|
---|
462 | * "The client _broadcasts_ a DHCPREQUEST message..."
|
---|
463 | */
|
---|
464 | /* NOINLINE: limit stack usage in caller */
|
---|
465 | static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
|
---|
466 | {
|
---|
467 | struct dhcp_packet packet;
|
---|
468 | struct in_addr addr;
|
---|
469 |
|
---|
470 | /*
|
---|
471 | * RFC 2131 4.3.2 DHCPREQUEST message
|
---|
472 | * ...
|
---|
473 | * If the DHCPREQUEST message contains a 'server identifier'
|
---|
474 | * option, the message is in response to a DHCPOFFER message.
|
---|
475 | * Otherwise, the message is a request to verify or extend an
|
---|
476 | * existing lease. If the client uses a 'client identifier'
|
---|
477 | * in a DHCPREQUEST message, it MUST use that same 'client identifier'
|
---|
478 | * in all subsequent messages. If the client included a list
|
---|
479 | * of requested parameters in a DHCPDISCOVER message, it MUST
|
---|
480 | * include that list in all subsequent messages.
|
---|
481 | */
|
---|
482 | /* Fill in: op, htype, hlen, cookie, chaddr fields,
|
---|
483 | * random xid field (we override it below),
|
---|
484 | * client-id option (unless -C), message type option:
|
---|
485 | */
|
---|
486 | init_packet(&packet, DHCPREQUEST);
|
---|
487 |
|
---|
488 | packet.xid = xid;
|
---|
489 | udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
|
---|
490 |
|
---|
491 | udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
|
---|
492 |
|
---|
493 | /* Add options: maxsize,
|
---|
494 | * optionally: hostname, fqdn, vendorclass,
|
---|
495 | * "param req" option according to -O, and options specified with -x
|
---|
496 | */
|
---|
497 | add_client_options(&packet);
|
---|
498 |
|
---|
499 | addr.s_addr = requested;
|
---|
500 | bb_info_msg("Sending select for %s...", inet_ntoa(addr));
|
---|
501 | return raw_bcast_from_client_config_ifindex(&packet);
|
---|
502 | }
|
---|
503 |
|
---|
504 | /* Unicast or broadcast a DHCP renew message */
|
---|
505 | /* NOINLINE: limit stack usage in caller */
|
---|
506 | static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
|
---|
507 | {
|
---|
508 | struct dhcp_packet packet;
|
---|
509 |
|
---|
510 | /*
|
---|
511 | * RFC 2131 4.3.2 DHCPREQUEST message
|
---|
512 | * ...
|
---|
513 | * DHCPREQUEST generated during RENEWING state:
|
---|
514 | *
|
---|
515 | * 'server identifier' MUST NOT be filled in, 'requested IP address'
|
---|
516 | * option MUST NOT be filled in, 'ciaddr' MUST be filled in with
|
---|
517 | * client's IP address. In this situation, the client is completely
|
---|
518 | * configured, and is trying to extend its lease. This message will
|
---|
519 | * be unicast, so no relay agents will be involved in its
|
---|
520 | * transmission. Because 'giaddr' is therefore not filled in, the
|
---|
521 | * DHCP server will trust the value in 'ciaddr', and use it when
|
---|
522 | * replying to the client.
|
---|
523 | */
|
---|
524 | /* Fill in: op, htype, hlen, cookie, chaddr fields,
|
---|
525 | * random xid field (we override it below),
|
---|
526 | * client-id option (unless -C), message type option:
|
---|
527 | */
|
---|
528 | init_packet(&packet, DHCPREQUEST);
|
---|
529 |
|
---|
530 | packet.xid = xid;
|
---|
531 | packet.ciaddr = ciaddr;
|
---|
532 |
|
---|
533 | /* Add options: maxsize,
|
---|
534 | * optionally: hostname, fqdn, vendorclass,
|
---|
535 | * "param req" option according to -O, and options specified with -x
|
---|
536 | */
|
---|
537 | add_client_options(&packet);
|
---|
538 |
|
---|
539 | bb_info_msg("Sending renew...");
|
---|
540 | if (server)
|
---|
541 | return udhcp_send_kernel_packet(&packet,
|
---|
542 | ciaddr, CLIENT_PORT,
|
---|
543 | server, SERVER_PORT);
|
---|
544 | return raw_bcast_from_client_config_ifindex(&packet);
|
---|
545 | }
|
---|
546 |
|
---|
547 | #if ENABLE_FEATURE_UDHCPC_ARPING
|
---|
548 | /* Broadcast a DHCP decline message */
|
---|
549 | /* NOINLINE: limit stack usage in caller */
|
---|
550 | static NOINLINE int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
|
---|
551 | {
|
---|
552 | struct dhcp_packet packet;
|
---|
553 |
|
---|
554 | /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
|
---|
555 | * client-id option (unless -C), message type option:
|
---|
556 | */
|
---|
557 | init_packet(&packet, DHCPDECLINE);
|
---|
558 |
|
---|
559 | /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
|
---|
560 | * but in case the server is buggy and wants DHCPDECLINE's xid
|
---|
561 | * to match the xid which started entire handshake,
|
---|
562 | * we use the same xid we used in initial DHCPDISCOVER:
|
---|
563 | */
|
---|
564 | packet.xid = xid;
|
---|
565 | /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
|
---|
566 | udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
|
---|
567 |
|
---|
568 | udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
|
---|
569 |
|
---|
570 | bb_info_msg("Sending decline...");
|
---|
571 | return raw_bcast_from_client_config_ifindex(&packet);
|
---|
572 | }
|
---|
573 | #endif
|
---|
574 |
|
---|
575 | /* Unicast a DHCP release message */
|
---|
576 | static int send_release(uint32_t server, uint32_t ciaddr)
|
---|
577 | {
|
---|
578 | struct dhcp_packet packet;
|
---|
579 |
|
---|
580 | /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
|
---|
581 | * client-id option (unless -C), message type option:
|
---|
582 | */
|
---|
583 | init_packet(&packet, DHCPRELEASE);
|
---|
584 |
|
---|
585 | /* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */
|
---|
586 | packet.ciaddr = ciaddr;
|
---|
587 |
|
---|
588 | udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
|
---|
589 |
|
---|
590 | bb_info_msg("Sending release...");
|
---|
591 | return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
|
---|
592 | }
|
---|
593 |
|
---|
594 | /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
|
---|
595 | /* NOINLINE: limit stack usage in caller */
|
---|
596 | static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
|
---|
597 | {
|
---|
598 | int bytes;
|
---|
599 | struct ip_udp_dhcp_packet packet;
|
---|
600 | uint16_t check;
|
---|
601 |
|
---|
602 | memset(&packet, 0, sizeof(packet));
|
---|
603 | bytes = safe_read(fd, &packet, sizeof(packet));
|
---|
604 | if (bytes < 0) {
|
---|
605 | log1("Packet read error, ignoring");
|
---|
606 | /* NB: possible down interface, etc. Caller should pause. */
|
---|
607 | return bytes; /* returns -1 */
|
---|
608 | }
|
---|
609 |
|
---|
610 | if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
|
---|
611 | log1("Packet is too short, ignoring");
|
---|
612 | return -2;
|
---|
613 | }
|
---|
614 |
|
---|
615 | if (bytes < ntohs(packet.ip.tot_len)) {
|
---|
616 | /* packet is bigger than sizeof(packet), we did partial read */
|
---|
617 | log1("Oversized packet, ignoring");
|
---|
618 | return -2;
|
---|
619 | }
|
---|
620 |
|
---|
621 | /* ignore any extra garbage bytes */
|
---|
622 | bytes = ntohs(packet.ip.tot_len);
|
---|
623 |
|
---|
624 | /* make sure its the right packet for us, and that it passes sanity checks */
|
---|
625 | if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
|
---|
626 | || packet.ip.ihl != (sizeof(packet.ip) >> 2)
|
---|
627 | || packet.udp.dest != htons(CLIENT_PORT)
|
---|
628 | /* || bytes > (int) sizeof(packet) - can't happen */
|
---|
629 | || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
|
---|
630 | ) {
|
---|
631 | log1("Unrelated/bogus packet, ignoring");
|
---|
632 | return -2;
|
---|
633 | }
|
---|
634 |
|
---|
635 | /* verify IP checksum */
|
---|
636 | check = packet.ip.check;
|
---|
637 | packet.ip.check = 0;
|
---|
638 | if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
|
---|
639 | log1("Bad IP header checksum, ignoring");
|
---|
640 | return -2;
|
---|
641 | }
|
---|
642 |
|
---|
643 | /* verify UDP checksum. IP header has to be modified for this */
|
---|
644 | memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
|
---|
645 | /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
|
---|
646 | packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
|
---|
647 | check = packet.udp.check;
|
---|
648 | packet.udp.check = 0;
|
---|
649 | if (check && check != udhcp_checksum(&packet, bytes)) {
|
---|
650 | log1("Packet with bad UDP checksum received, ignoring");
|
---|
651 | return -2;
|
---|
652 | }
|
---|
653 |
|
---|
654 | memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
|
---|
655 |
|
---|
656 | if (dhcp_pkt->cookie != htonl(DHCP_MAGIC)) {
|
---|
657 | bb_info_msg("Packet with bad magic, ignoring");
|
---|
658 | return -2;
|
---|
659 | }
|
---|
660 | log1("Got valid DHCP packet");
|
---|
661 | udhcp_dump_packet(dhcp_pkt);
|
---|
662 | return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
|
---|
663 | }
|
---|
664 |
|
---|
665 |
|
---|
666 | /*** Main ***/
|
---|
667 |
|
---|
668 | static int sockfd = -1;
|
---|
669 |
|
---|
670 | #define LISTEN_NONE 0
|
---|
671 | #define LISTEN_KERNEL 1
|
---|
672 | #define LISTEN_RAW 2
|
---|
673 | static smallint listen_mode;
|
---|
674 |
|
---|
675 | /* initial state: (re)start DHCP negotiation */
|
---|
676 | #define INIT_SELECTING 0
|
---|
677 | /* discover was sent, DHCPOFFER reply received */
|
---|
678 | #define REQUESTING 1
|
---|
679 | /* select/renew was sent, DHCPACK reply received */
|
---|
680 | #define BOUND 2
|
---|
681 | /* half of lease passed, want to renew it by sending unicast renew requests */
|
---|
682 | #define RENEWING 3
|
---|
683 | /* renew requests were not answered, lease is almost over, send broadcast renew */
|
---|
684 | #define REBINDING 4
|
---|
685 | /* manually requested renew (SIGUSR1) */
|
---|
686 | #define RENEW_REQUESTED 5
|
---|
687 | /* release, possibly manually requested (SIGUSR2) */
|
---|
688 | #define RELEASED 6
|
---|
689 | static smallint state;
|
---|
690 |
|
---|
691 | static int udhcp_raw_socket(int ifindex)
|
---|
692 | {
|
---|
693 | int fd;
|
---|
694 | struct sockaddr_ll sock;
|
---|
695 |
|
---|
696 | /*
|
---|
697 | * Comment:
|
---|
698 | *
|
---|
699 | * I've selected not to see LL header, so BPF doesn't see it, too.
|
---|
700 | * The filter may also pass non-IP and non-ARP packets, but we do
|
---|
701 | * a more complete check when receiving the message in userspace.
|
---|
702 | *
|
---|
703 | * and filter shamelessly stolen from:
|
---|
704 | *
|
---|
705 | * http://www.flamewarmaster.de/software/dhcpclient/
|
---|
706 | *
|
---|
707 | * There are a few other interesting ideas on that page (look under
|
---|
708 | * "Motivation"). Use of netlink events is most interesting. Think
|
---|
709 | * of various network servers listening for events and reconfiguring.
|
---|
710 | * That would obsolete sending HUP signals and/or make use of restarts.
|
---|
711 | *
|
---|
712 | * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
|
---|
713 | * License: GPL v2.
|
---|
714 | *
|
---|
715 | * TODO: make conditional?
|
---|
716 | */
|
---|
717 | #define SERVER_AND_CLIENT_PORTS ((67 << 16) + 68)
|
---|
718 | static const struct sock_filter filter_instr[] = {
|
---|
719 | /* check for udp */
|
---|
720 | BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
|
---|
721 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 2, 0), /* L5, L1, is UDP? */
|
---|
722 | /* ugly check for arp on ethernet-like and IPv4 */
|
---|
723 | BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2), /* L1: */
|
---|
724 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x08000604, 3, 4), /* L3, L4 */
|
---|
725 | /* skip IP header */
|
---|
726 | BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* L5: */
|
---|
727 | /* check udp source and destination ports */
|
---|
728 | BPF_STMT(BPF_LD|BPF_W|BPF_IND, 0),
|
---|
729 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, SERVER_AND_CLIENT_PORTS, 0, 1), /* L3, L4 */
|
---|
730 | /* returns */
|
---|
731 | BPF_STMT(BPF_RET|BPF_K, 0x0fffffff ), /* L3: pass */
|
---|
732 | BPF_STMT(BPF_RET|BPF_K, 0), /* L4: reject */
|
---|
733 | };
|
---|
734 | static const struct sock_fprog filter_prog = {
|
---|
735 | .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
|
---|
736 | /* casting const away: */
|
---|
737 | .filter = (struct sock_filter *) filter_instr,
|
---|
738 | };
|
---|
739 |
|
---|
740 | log1("Opening raw socket on ifindex %d", ifindex); //log2?
|
---|
741 |
|
---|
742 | fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
|
---|
743 | log1("Got raw socket fd %d", fd); //log2?
|
---|
744 |
|
---|
745 | if (SERVER_PORT == 67 && CLIENT_PORT == 68) {
|
---|
746 | /* Use only if standard ports are in use */
|
---|
747 | /* Ignoring error (kernel may lack support for this) */
|
---|
748 | if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
|
---|
749 | sizeof(filter_prog)) >= 0)
|
---|
750 | log1("Attached filter to raw socket fd %d", fd); // log?
|
---|
751 | }
|
---|
752 |
|
---|
753 | sock.sll_family = AF_PACKET;
|
---|
754 | sock.sll_protocol = htons(ETH_P_IP);
|
---|
755 | sock.sll_ifindex = ifindex;
|
---|
756 | xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
|
---|
757 | log1("Created raw socket");
|
---|
758 |
|
---|
759 | return fd;
|
---|
760 | }
|
---|
761 |
|
---|
762 | static void change_listen_mode(int new_mode)
|
---|
763 | {
|
---|
764 | log1("Entering listen mode: %s",
|
---|
765 | new_mode != LISTEN_NONE
|
---|
766 | ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
|
---|
767 | : "none"
|
---|
768 | );
|
---|
769 |
|
---|
770 | listen_mode = new_mode;
|
---|
771 | if (sockfd >= 0) {
|
---|
772 | close(sockfd);
|
---|
773 | sockfd = -1;
|
---|
774 | }
|
---|
775 | if (new_mode == LISTEN_KERNEL)
|
---|
776 | sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
|
---|
777 | else if (new_mode != LISTEN_NONE)
|
---|
778 | sockfd = udhcp_raw_socket(client_config.ifindex);
|
---|
779 | /* else LISTEN_NONE: sockfd stays closed */
|
---|
780 | }
|
---|
781 |
|
---|
782 | static void perform_renew(void)
|
---|
783 | {
|
---|
784 | bb_info_msg("Performing a DHCP renew");
|
---|
785 | switch (state) {
|
---|
786 | case BOUND:
|
---|
787 | change_listen_mode(LISTEN_KERNEL);
|
---|
788 | case RENEWING:
|
---|
789 | case REBINDING:
|
---|
790 | state = RENEW_REQUESTED;
|
---|
791 | break;
|
---|
792 | case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
|
---|
793 | udhcp_run_script(NULL, "deconfig");
|
---|
794 | case REQUESTING:
|
---|
795 | case RELEASED:
|
---|
796 | change_listen_mode(LISTEN_RAW);
|
---|
797 | state = INIT_SELECTING;
|
---|
798 | break;
|
---|
799 | case INIT_SELECTING:
|
---|
800 | break;
|
---|
801 | }
|
---|
802 | }
|
---|
803 |
|
---|
804 | static void perform_release(uint32_t requested_ip, uint32_t server_addr)
|
---|
805 | {
|
---|
806 | char buffer[sizeof("255.255.255.255")];
|
---|
807 | struct in_addr temp_addr;
|
---|
808 |
|
---|
809 | /* send release packet */
|
---|
810 | if (state == BOUND || state == RENEWING || state == REBINDING) {
|
---|
811 | temp_addr.s_addr = server_addr;
|
---|
812 | strcpy(buffer, inet_ntoa(temp_addr));
|
---|
813 | temp_addr.s_addr = requested_ip;
|
---|
814 | bb_info_msg("Unicasting a release of %s to %s",
|
---|
815 | inet_ntoa(temp_addr), buffer);
|
---|
816 | send_release(server_addr, requested_ip); /* unicast */
|
---|
817 | udhcp_run_script(NULL, "deconfig");
|
---|
818 | }
|
---|
819 | bb_info_msg("Entering released state");
|
---|
820 |
|
---|
821 | change_listen_mode(LISTEN_NONE);
|
---|
822 | state = RELEASED;
|
---|
823 | }
|
---|
824 |
|
---|
825 | static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
|
---|
826 | {
|
---|
827 | uint8_t *storage;
|
---|
828 | int len = strnlen(str, 255);
|
---|
829 | storage = xzalloc(len + extra + OPT_DATA);
|
---|
830 | storage[OPT_CODE] = code;
|
---|
831 | storage[OPT_LEN] = len + extra;
|
---|
832 | memcpy(storage + extra + OPT_DATA, str, len);
|
---|
833 | return storage;
|
---|
834 | }
|
---|
835 |
|
---|
836 | #if BB_MMU
|
---|
837 | static void client_background(void)
|
---|
838 | {
|
---|
839 | bb_daemonize(0);
|
---|
840 | logmode &= ~LOGMODE_STDIO;
|
---|
841 | /* rewrite pidfile, as our pid is different now */
|
---|
842 | write_pidfile(client_config.pidfile);
|
---|
843 | }
|
---|
844 | #endif
|
---|
845 |
|
---|
846 | //usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
---|
847 | //usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
|
---|
848 | //usage:#else
|
---|
849 | //usage:# define IF_UDHCP_VERBOSE(...)
|
---|
850 | //usage:#endif
|
---|
851 | //usage:#define udhcpc_trivial_usage
|
---|
852 | //usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oCR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
|
---|
853 | //usage: " [-H HOSTNAME] [-V VENDOR] [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
|
---|
854 | //usage:#define udhcpc_full_usage "\n"
|
---|
855 | //usage: IF_LONG_OPTS(
|
---|
856 | //usage: "\n -i,--interface IFACE Interface to use (default eth0)"
|
---|
857 | //usage: "\n -p,--pidfile FILE Create pidfile"
|
---|
858 | //usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
|
---|
859 | //usage: "\n -t,--retries N Send up to N discover packets"
|
---|
860 | //usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
|
---|
861 | //usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
|
---|
862 | //usage: "\n -f,--foreground Run in foreground"
|
---|
863 | //usage: USE_FOR_MMU(
|
---|
864 | //usage: "\n -b,--background Background if lease is not obtained"
|
---|
865 | //usage: )
|
---|
866 | //usage: "\n -n,--now Exit if lease is not obtained"
|
---|
867 | //usage: "\n -q,--quit Exit after obtaining lease"
|
---|
868 | //usage: "\n -R,--release Release IP on exit"
|
---|
869 | //usage: "\n -S,--syslog Log to syslog too"
|
---|
870 | //usage: IF_FEATURE_UDHCP_PORT(
|
---|
871 | //usage: "\n -P,--client-port N Use port N (default 68)"
|
---|
872 | //usage: )
|
---|
873 | //usage: IF_FEATURE_UDHCPC_ARPING(
|
---|
874 | //usage: "\n -a,--arping Use arping to validate offered address"
|
---|
875 | //usage: )
|
---|
876 | //usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
|
---|
877 | //usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
|
---|
878 | //usage: "\n -r,--request IP Request this IP address"
|
---|
879 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
|
---|
880 | //usage: "\n Examples of string, numeric, and hex byte opts:"
|
---|
881 | //usage: "\n -x hostname:bbox - option 12"
|
---|
882 | //usage: "\n -x lease:3600 - option 51 (lease time)"
|
---|
883 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
|
---|
884 | //usage: "\n -F,--fqdn NAME Ask server to update DNS mapping for NAME"
|
---|
885 | //usage: "\n -H,-h,--hostname NAME Send NAME as client hostname (default none)"
|
---|
886 | //usage: "\n -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')"
|
---|
887 | //usage: "\n -C,--clientid-none Don't send MAC as client identifier"
|
---|
888 | //usage: IF_UDHCP_VERBOSE(
|
---|
889 | //usage: "\n -v Verbose"
|
---|
890 | //usage: )
|
---|
891 | //usage: )
|
---|
892 | //usage: IF_NOT_LONG_OPTS(
|
---|
893 | //usage: "\n -i IFACE Interface to use (default eth0)"
|
---|
894 | //usage: "\n -p FILE Create pidfile"
|
---|
895 | //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
|
---|
896 | //usage: "\n -t N Send up to N discover packets"
|
---|
897 | //usage: "\n -T N Pause between packets (default 3 seconds)"
|
---|
898 | //usage: "\n -A N Wait N seconds (default 20) after failure"
|
---|
899 | //usage: "\n -f Run in foreground"
|
---|
900 | //usage: USE_FOR_MMU(
|
---|
901 | //usage: "\n -b Background if lease is not obtained"
|
---|
902 | //usage: )
|
---|
903 | //usage: "\n -n Exit if lease is not obtained"
|
---|
904 | //usage: "\n -q Exit after obtaining lease"
|
---|
905 | //usage: "\n -R Release IP on exit"
|
---|
906 | //usage: "\n -S Log to syslog too"
|
---|
907 | //usage: IF_FEATURE_UDHCP_PORT(
|
---|
908 | //usage: "\n -P N Use port N (default 68)"
|
---|
909 | //usage: )
|
---|
910 | //usage: IF_FEATURE_UDHCPC_ARPING(
|
---|
911 | //usage: "\n -a Use arping to validate offered address"
|
---|
912 | //usage: )
|
---|
913 | //usage: "\n -O OPT Request option OPT from server (cumulative)"
|
---|
914 | //usage: "\n -o Don't request any options (unless -O is given)"
|
---|
915 | //usage: "\n -r IP Request this IP address"
|
---|
916 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
|
---|
917 | //usage: "\n Examples of string, numeric, and hex byte opts:"
|
---|
918 | //usage: "\n -x hostname:bbox - option 12"
|
---|
919 | //usage: "\n -x lease:3600 - option 51 (lease time)"
|
---|
920 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
|
---|
921 | //usage: "\n -F NAME Ask server to update DNS mapping for NAME"
|
---|
922 | //usage: "\n -H,-h NAME Send NAME as client hostname (default none)"
|
---|
923 | //usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')"
|
---|
924 | //usage: "\n -C Don't send MAC as client identifier"
|
---|
925 | //usage: IF_UDHCP_VERBOSE(
|
---|
926 | //usage: "\n -v Verbose"
|
---|
927 | //usage: )
|
---|
928 | //usage: )
|
---|
929 |
|
---|
930 | int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
931 | int udhcpc_main(int argc UNUSED_PARAM, char **argv)
|
---|
932 | {
|
---|
933 | uint8_t *temp, *message;
|
---|
934 | const char *str_V, *str_h, *str_F, *str_r;
|
---|
935 | IF_FEATURE_UDHCP_PORT(char *str_P;)
|
---|
936 | void *clientid_mac_ptr;
|
---|
937 | llist_t *list_O = NULL;
|
---|
938 | llist_t *list_x = NULL;
|
---|
939 | int tryagain_timeout = 20;
|
---|
940 | int discover_timeout = 3;
|
---|
941 | int discover_retries = 3;
|
---|
942 | uint32_t server_addr = server_addr; /* for compiler */
|
---|
943 | uint32_t requested_ip = 0;
|
---|
944 | uint32_t xid = 0;
|
---|
945 | uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
|
---|
946 | int packet_num;
|
---|
947 | int timeout; /* must be signed */
|
---|
948 | unsigned already_waited_sec;
|
---|
949 | unsigned opt;
|
---|
950 | int max_fd;
|
---|
951 | int retval;
|
---|
952 | struct timeval tv;
|
---|
953 | struct dhcp_packet packet;
|
---|
954 | fd_set rfds;
|
---|
955 |
|
---|
956 | #if ENABLE_LONG_OPTS
|
---|
957 | static const char udhcpc_longopts[] ALIGN1 =
|
---|
958 | "clientid-none\0" No_argument "C"
|
---|
959 | "vendorclass\0" Required_argument "V"
|
---|
960 | "hostname\0" Required_argument "H"
|
---|
961 | "fqdn\0" Required_argument "F"
|
---|
962 | "interface\0" Required_argument "i"
|
---|
963 | "now\0" No_argument "n"
|
---|
964 | "pidfile\0" Required_argument "p"
|
---|
965 | "quit\0" No_argument "q"
|
---|
966 | "release\0" No_argument "R"
|
---|
967 | "request\0" Required_argument "r"
|
---|
968 | "script\0" Required_argument "s"
|
---|
969 | "timeout\0" Required_argument "T"
|
---|
970 | "version\0" No_argument "v"
|
---|
971 | "retries\0" Required_argument "t"
|
---|
972 | "tryagain\0" Required_argument "A"
|
---|
973 | "syslog\0" No_argument "S"
|
---|
974 | "request-option\0" Required_argument "O"
|
---|
975 | "no-default-options\0" No_argument "o"
|
---|
976 | "foreground\0" No_argument "f"
|
---|
977 | "background\0" No_argument "b"
|
---|
978 | IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
|
---|
979 | IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
|
---|
980 | ;
|
---|
981 | #endif
|
---|
982 | enum {
|
---|
983 | OPT_C = 1 << 0,
|
---|
984 | OPT_V = 1 << 1,
|
---|
985 | OPT_H = 1 << 2,
|
---|
986 | OPT_h = 1 << 3,
|
---|
987 | OPT_F = 1 << 4,
|
---|
988 | OPT_i = 1 << 5,
|
---|
989 | OPT_n = 1 << 6,
|
---|
990 | OPT_p = 1 << 7,
|
---|
991 | OPT_q = 1 << 8,
|
---|
992 | OPT_R = 1 << 9,
|
---|
993 | OPT_r = 1 << 10,
|
---|
994 | OPT_s = 1 << 11,
|
---|
995 | OPT_T = 1 << 12,
|
---|
996 | OPT_t = 1 << 13,
|
---|
997 | OPT_S = 1 << 14,
|
---|
998 | OPT_A = 1 << 15,
|
---|
999 | OPT_O = 1 << 16,
|
---|
1000 | OPT_o = 1 << 17,
|
---|
1001 | OPT_x = 1 << 18,
|
---|
1002 | OPT_f = 1 << 19,
|
---|
1003 | /* The rest has variable bit positions, need to be clever */
|
---|
1004 | OPTBIT_f = 19,
|
---|
1005 | USE_FOR_MMU( OPTBIT_b,)
|
---|
1006 | IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
|
---|
1007 | IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
|
---|
1008 | USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
|
---|
1009 | IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
|
---|
1010 | IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
|
---|
1011 | };
|
---|
1012 |
|
---|
1013 | /* Default options */
|
---|
1014 | IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
|
---|
1015 | IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
|
---|
1016 | client_config.interface = "eth0";
|
---|
1017 | client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
|
---|
1018 | str_V = "udhcp "BB_VER;
|
---|
1019 |
|
---|
1020 | /* Parse command line */
|
---|
1021 | /* O,x: list; -T,-t,-A take numeric param */
|
---|
1022 | opt_complementary = "O::x::T+:t+:A+"
|
---|
1023 | #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
---|
1024 | ":vv"
|
---|
1025 | #endif
|
---|
1026 | ;
|
---|
1027 | IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
|
---|
1028 | opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:f"
|
---|
1029 | USE_FOR_MMU("b")
|
---|
1030 | IF_FEATURE_UDHCPC_ARPING("a")
|
---|
1031 | IF_FEATURE_UDHCP_PORT("P:")
|
---|
1032 | "v"
|
---|
1033 | , &str_V, &str_h, &str_h, &str_F
|
---|
1034 | , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
|
---|
1035 | , &client_config.script /* s */
|
---|
1036 | , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
|
---|
1037 | , &list_O
|
---|
1038 | , &list_x
|
---|
1039 | IF_FEATURE_UDHCP_PORT(, &str_P)
|
---|
1040 | #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
---|
1041 | , &dhcp_verbose
|
---|
1042 | #endif
|
---|
1043 | );
|
---|
1044 | if (opt & (OPT_h|OPT_H))
|
---|
1045 | client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
|
---|
1046 | if (opt & OPT_F) {
|
---|
1047 | /* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
|
---|
1048 | client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
|
---|
1049 | /* Flag bits: 0000NEOS
|
---|
1050 | * S: 1 = Client requests server to update A RR in DNS as well as PTR
|
---|
1051 | * O: 1 = Server indicates to client that DNS has been updated regardless
|
---|
1052 | * E: 1 = Name is in DNS format, i.e. <4>host<6>domain<3>com<0>,
|
---|
1053 | * not "host.domain.com". Format 0 is obsolete.
|
---|
1054 | * N: 1 = Client requests server to not update DNS (S must be 0 then)
|
---|
1055 | * Two [0] bytes which follow are deprecated and must be 0.
|
---|
1056 | */
|
---|
1057 | client_config.fqdn[OPT_DATA + 0] = 0x1;
|
---|
1058 | /*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
|
---|
1059 | /*client_config.fqdn[OPT_DATA + 2] = 0; */
|
---|
1060 | }
|
---|
1061 | if (opt & OPT_r)
|
---|
1062 | requested_ip = inet_addr(str_r);
|
---|
1063 | #if ENABLE_FEATURE_UDHCP_PORT
|
---|
1064 | if (opt & OPT_P) {
|
---|
1065 | CLIENT_PORT = xatou16(str_P);
|
---|
1066 | SERVER_PORT = CLIENT_PORT - 1;
|
---|
1067 | }
|
---|
1068 | #endif
|
---|
1069 | if (opt & OPT_o)
|
---|
1070 | client_config.no_default_options = 1;
|
---|
1071 | while (list_O) {
|
---|
1072 | char *optstr = llist_pop(&list_O);
|
---|
1073 | unsigned n = udhcp_option_idx(optstr);
|
---|
1074 | n = dhcp_optflags[n].code;
|
---|
1075 | client_config.opt_mask[n >> 3] |= 1 << (n & 7);
|
---|
1076 | }
|
---|
1077 | while (list_x) {
|
---|
1078 | char *optstr = llist_pop(&list_x);
|
---|
1079 | char *colon = strchr(optstr, ':');
|
---|
1080 | if (colon)
|
---|
1081 | *colon = ' ';
|
---|
1082 | /* now it looks similar to udhcpd's config file line:
|
---|
1083 | * "optname optval", using the common routine: */
|
---|
1084 | udhcp_str2optset(optstr, &client_config.options);
|
---|
1085 | }
|
---|
1086 |
|
---|
1087 | if (udhcp_read_interface(client_config.interface,
|
---|
1088 | &client_config.ifindex,
|
---|
1089 | NULL,
|
---|
1090 | client_config.client_mac)
|
---|
1091 | ) {
|
---|
1092 | return 1;
|
---|
1093 | }
|
---|
1094 |
|
---|
1095 | clientid_mac_ptr = NULL;
|
---|
1096 | if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) {
|
---|
1097 | /* not suppressed and not set, set the default client ID */
|
---|
1098 | client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
|
---|
1099 | client_config.clientid[OPT_DATA] = 1; /* type: ethernet */
|
---|
1100 | clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
|
---|
1101 | memcpy(clientid_mac_ptr, client_config.client_mac, 6);
|
---|
1102 | }
|
---|
1103 | if (str_V[0] != '\0')
|
---|
1104 | client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
|
---|
1105 | #if !BB_MMU
|
---|
1106 | /* on NOMMU reexec (i.e., background) early */
|
---|
1107 | if (!(opt & OPT_f)) {
|
---|
1108 | bb_daemonize_or_rexec(0 /* flags */, argv);
|
---|
1109 | logmode = LOGMODE_NONE;
|
---|
1110 | }
|
---|
1111 | #endif
|
---|
1112 | if (opt & OPT_S) {
|
---|
1113 | openlog(applet_name, LOG_PID, LOG_DAEMON);
|
---|
1114 | logmode |= LOGMODE_SYSLOG;
|
---|
1115 | }
|
---|
1116 |
|
---|
1117 | /* Make sure fd 0,1,2 are open */
|
---|
1118 | bb_sanitize_stdio();
|
---|
1119 | /* Equivalent of doing a fflush after every \n */
|
---|
1120 | setlinebuf(stdout);
|
---|
1121 | /* Create pidfile */
|
---|
1122 | write_pidfile(client_config.pidfile);
|
---|
1123 | /* Goes to stdout (unless NOMMU) and possibly syslog */
|
---|
1124 | bb_info_msg("%s (v"BB_VER") started", applet_name);
|
---|
1125 | /* Set up the signal pipe */
|
---|
1126 | udhcp_sp_setup();
|
---|
1127 | /* We want random_xid to be random... */
|
---|
1128 | srand(monotonic_us());
|
---|
1129 |
|
---|
1130 | state = INIT_SELECTING;
|
---|
1131 | udhcp_run_script(NULL, "deconfig");
|
---|
1132 | change_listen_mode(LISTEN_RAW);
|
---|
1133 | packet_num = 0;
|
---|
1134 | timeout = 0;
|
---|
1135 | already_waited_sec = 0;
|
---|
1136 |
|
---|
1137 | /* Main event loop. select() waits on signal pipe and possibly
|
---|
1138 | * on sockfd.
|
---|
1139 | * "continue" statements in code below jump to the top of the loop.
|
---|
1140 | */
|
---|
1141 | for (;;) {
|
---|
1142 | /* silence "uninitialized!" warning */
|
---|
1143 | unsigned timestamp_before_wait = timestamp_before_wait;
|
---|
1144 |
|
---|
1145 | //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
|
---|
1146 |
|
---|
1147 | /* Was opening raw or udp socket here
|
---|
1148 | * if (listen_mode != LISTEN_NONE && sockfd < 0),
|
---|
1149 | * but on fast network renew responses return faster
|
---|
1150 | * than we open sockets. Thus this code is moved
|
---|
1151 | * to change_listen_mode(). Thus we open listen socket
|
---|
1152 | * BEFORE we send renew request (see "case BOUND:"). */
|
---|
1153 |
|
---|
1154 | max_fd = udhcp_sp_fd_set(&rfds, sockfd);
|
---|
1155 |
|
---|
1156 | tv.tv_sec = timeout - already_waited_sec;
|
---|
1157 | tv.tv_usec = 0;
|
---|
1158 | retval = 0;
|
---|
1159 | /* If we already timed out, fall through with retval = 0, else... */
|
---|
1160 | if ((int)tv.tv_sec > 0) {
|
---|
1161 | timestamp_before_wait = (unsigned)monotonic_sec();
|
---|
1162 | log1("Waiting on select...");
|
---|
1163 | retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
|
---|
1164 | if (retval < 0) {
|
---|
1165 | /* EINTR? A signal was caught, don't panic */
|
---|
1166 | if (errno == EINTR) {
|
---|
1167 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
---|
1168 | continue;
|
---|
1169 | }
|
---|
1170 | /* Else: an error occured, panic! */
|
---|
1171 | bb_perror_msg_and_die("select");
|
---|
1172 | }
|
---|
1173 | }
|
---|
1174 |
|
---|
1175 | /* If timeout dropped to zero, time to become active:
|
---|
1176 | * resend discover/renew/whatever
|
---|
1177 | */
|
---|
1178 | if (retval == 0) {
|
---|
1179 | /* When running on a bridge, the ifindex may have changed
|
---|
1180 | * (e.g. if member interfaces were added/removed
|
---|
1181 | * or if the status of the bridge changed).
|
---|
1182 | * Refresh ifindex and client_mac:
|
---|
1183 | */
|
---|
1184 | if (udhcp_read_interface(client_config.interface,
|
---|
1185 | &client_config.ifindex,
|
---|
1186 | NULL,
|
---|
1187 | client_config.client_mac)
|
---|
1188 | ) {
|
---|
1189 | return 1; /* iface is gone? */
|
---|
1190 | }
|
---|
1191 | if (clientid_mac_ptr)
|
---|
1192 | memcpy(clientid_mac_ptr, client_config.client_mac, 6);
|
---|
1193 |
|
---|
1194 | /* We will restart the wait in any case */
|
---|
1195 | already_waited_sec = 0;
|
---|
1196 |
|
---|
1197 | switch (state) {
|
---|
1198 | case INIT_SELECTING:
|
---|
1199 | if (packet_num < discover_retries) {
|
---|
1200 | if (packet_num == 0)
|
---|
1201 | xid = random_xid();
|
---|
1202 | /* broadcast */
|
---|
1203 | send_discover(xid, requested_ip);
|
---|
1204 | timeout = discover_timeout;
|
---|
1205 | packet_num++;
|
---|
1206 | continue;
|
---|
1207 | }
|
---|
1208 | leasefail:
|
---|
1209 | udhcp_run_script(NULL, "leasefail");
|
---|
1210 | #if BB_MMU /* -b is not supported on NOMMU */
|
---|
1211 | if (opt & OPT_b) { /* background if no lease */
|
---|
1212 | bb_info_msg("No lease, forking to background");
|
---|
1213 | client_background();
|
---|
1214 | /* do not background again! */
|
---|
1215 | opt = ((opt & ~OPT_b) | OPT_f);
|
---|
1216 | } else
|
---|
1217 | #endif
|
---|
1218 | if (opt & OPT_n) { /* abort if no lease */
|
---|
1219 | bb_info_msg("No lease, failing");
|
---|
1220 | retval = 1;
|
---|
1221 | goto ret;
|
---|
1222 | }
|
---|
1223 | /* wait before trying again */
|
---|
1224 | timeout = tryagain_timeout;
|
---|
1225 | packet_num = 0;
|
---|
1226 | continue;
|
---|
1227 | case REQUESTING:
|
---|
1228 | if (packet_num < discover_retries) {
|
---|
1229 | /* send broadcast select packet */
|
---|
1230 | send_select(xid, server_addr, requested_ip);
|
---|
1231 | timeout = discover_timeout;
|
---|
1232 | packet_num++;
|
---|
1233 | continue;
|
---|
1234 | }
|
---|
1235 | /* Timed out, go back to init state.
|
---|
1236 | * "discover...select...discover..." loops
|
---|
1237 | * were seen in the wild. Treat them similarly
|
---|
1238 | * to "no response to discover" case */
|
---|
1239 | change_listen_mode(LISTEN_RAW);
|
---|
1240 | state = INIT_SELECTING;
|
---|
1241 | goto leasefail;
|
---|
1242 | case BOUND:
|
---|
1243 | /* 1/2 lease passed, enter renewing state */
|
---|
1244 | state = RENEWING;
|
---|
1245 | change_listen_mode(LISTEN_KERNEL);
|
---|
1246 | log1("Entering renew state");
|
---|
1247 | /* fall right through */
|
---|
1248 | case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
|
---|
1249 | case_RENEW_REQUESTED:
|
---|
1250 | case RENEWING:
|
---|
1251 | if (timeout > 60) {
|
---|
1252 | /* send an unicast renew request */
|
---|
1253 | /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
|
---|
1254 | * a new UDP socket for sending inside send_renew.
|
---|
1255 | * I hazard to guess existing listening socket
|
---|
1256 | * is somehow conflicting with it, but why is it
|
---|
1257 | * not deterministic then?! Strange.
|
---|
1258 | * Anyway, it does recover by eventually failing through
|
---|
1259 | * into INIT_SELECTING state.
|
---|
1260 | */
|
---|
1261 | send_renew(xid, server_addr, requested_ip);
|
---|
1262 | timeout >>= 1;
|
---|
1263 | continue;
|
---|
1264 | }
|
---|
1265 | /* Timed out, enter rebinding state */
|
---|
1266 | log1("Entering rebinding state");
|
---|
1267 | state = REBINDING;
|
---|
1268 | /* fall right through */
|
---|
1269 | case REBINDING:
|
---|
1270 | /* Switch to bcast receive */
|
---|
1271 | change_listen_mode(LISTEN_RAW);
|
---|
1272 | /* Lease is *really* about to run out,
|
---|
1273 | * try to find DHCP server using broadcast */
|
---|
1274 | if (timeout > 0) {
|
---|
1275 | /* send a broadcast renew request */
|
---|
1276 | send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
|
---|
1277 | timeout >>= 1;
|
---|
1278 | continue;
|
---|
1279 | }
|
---|
1280 | /* Timed out, enter init state */
|
---|
1281 | bb_info_msg("Lease lost, entering init state");
|
---|
1282 | udhcp_run_script(NULL, "deconfig");
|
---|
1283 | state = INIT_SELECTING;
|
---|
1284 | /*timeout = 0; - already is */
|
---|
1285 | packet_num = 0;
|
---|
1286 | continue;
|
---|
1287 | /* case RELEASED: */
|
---|
1288 | }
|
---|
1289 | /* yah, I know, *you* say it would never happen */
|
---|
1290 | timeout = INT_MAX;
|
---|
1291 | continue; /* back to main loop */
|
---|
1292 | } /* if select timed out */
|
---|
1293 |
|
---|
1294 | /* select() didn't timeout, something happened */
|
---|
1295 |
|
---|
1296 | /* Is it a signal? */
|
---|
1297 | /* note: udhcp_sp_read checks FD_ISSET before reading */
|
---|
1298 | switch (udhcp_sp_read(&rfds)) {
|
---|
1299 | case SIGUSR1:
|
---|
1300 | perform_renew();
|
---|
1301 | if (state == RENEW_REQUESTED)
|
---|
1302 | goto case_RENEW_REQUESTED;
|
---|
1303 | /* Start things over */
|
---|
1304 | packet_num = 0;
|
---|
1305 | /* Kill any timeouts, user wants this to hurry along */
|
---|
1306 | timeout = 0;
|
---|
1307 | continue;
|
---|
1308 | case SIGUSR2:
|
---|
1309 | perform_release(requested_ip, server_addr);
|
---|
1310 | timeout = INT_MAX;
|
---|
1311 | continue;
|
---|
1312 | case SIGTERM:
|
---|
1313 | bb_info_msg("Received SIGTERM");
|
---|
1314 | if (opt & OPT_R) /* release on quit */
|
---|
1315 | perform_release(requested_ip, server_addr);
|
---|
1316 | goto ret0;
|
---|
1317 | }
|
---|
1318 |
|
---|
1319 | /* Is it a packet? */
|
---|
1320 | if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
|
---|
1321 | continue; /* no */
|
---|
1322 |
|
---|
1323 | {
|
---|
1324 | int len;
|
---|
1325 |
|
---|
1326 | /* A packet is ready, read it */
|
---|
1327 | if (listen_mode == LISTEN_KERNEL)
|
---|
1328 | len = udhcp_recv_kernel_packet(&packet, sockfd);
|
---|
1329 | else
|
---|
1330 | len = udhcp_recv_raw_packet(&packet, sockfd);
|
---|
1331 | if (len == -1) {
|
---|
1332 | /* Error is severe, reopen socket */
|
---|
1333 | bb_info_msg("Read error: %s, reopening socket", strerror(errno));
|
---|
1334 | sleep(discover_timeout); /* 3 seconds by default */
|
---|
1335 | change_listen_mode(listen_mode); /* just close and reopen */
|
---|
1336 | }
|
---|
1337 | /* If this packet will turn out to be unrelated/bogus,
|
---|
1338 | * we will go back and wait for next one.
|
---|
1339 | * Be sure timeout is properly decreased. */
|
---|
1340 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
---|
1341 | if (len < 0)
|
---|
1342 | continue;
|
---|
1343 | }
|
---|
1344 |
|
---|
1345 | if (packet.xid != xid) {
|
---|
1346 | log1("xid %x (our is %x), ignoring packet",
|
---|
1347 | (unsigned)packet.xid, (unsigned)xid);
|
---|
1348 | continue;
|
---|
1349 | }
|
---|
1350 |
|
---|
1351 | /* Ignore packets that aren't for us */
|
---|
1352 | if (packet.hlen != 6
|
---|
1353 | || memcmp(packet.chaddr, client_config.client_mac, 6) != 0
|
---|
1354 | ) {
|
---|
1355 | //FIXME: need to also check that last 10 bytes are zero
|
---|
1356 | log1("chaddr does not match, ignoring packet"); // log2?
|
---|
1357 | continue;
|
---|
1358 | }
|
---|
1359 |
|
---|
1360 | message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
|
---|
1361 | if (message == NULL) {
|
---|
1362 | bb_error_msg("no message type option, ignoring packet");
|
---|
1363 | continue;
|
---|
1364 | }
|
---|
1365 |
|
---|
1366 | switch (state) {
|
---|
1367 | case INIT_SELECTING:
|
---|
1368 | /* Must be a DHCPOFFER to one of our xid's */
|
---|
1369 | if (*message == DHCPOFFER) {
|
---|
1370 | /* TODO: why we don't just fetch server's IP from IP header? */
|
---|
1371 | temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
|
---|
1372 | if (!temp) {
|
---|
1373 | bb_error_msg("no server ID, ignoring packet");
|
---|
1374 | continue;
|
---|
1375 | /* still selecting - this server looks bad */
|
---|
1376 | }
|
---|
1377 | /* it IS unaligned sometimes, don't "optimize" */
|
---|
1378 | move_from_unaligned32(server_addr, temp);
|
---|
1379 | /*xid = packet.xid; - already is */
|
---|
1380 | requested_ip = packet.yiaddr;
|
---|
1381 |
|
---|
1382 | /* enter requesting state */
|
---|
1383 | state = REQUESTING;
|
---|
1384 | timeout = 0;
|
---|
1385 | packet_num = 0;
|
---|
1386 | already_waited_sec = 0;
|
---|
1387 | }
|
---|
1388 | continue;
|
---|
1389 | case REQUESTING:
|
---|
1390 | case RENEWING:
|
---|
1391 | case RENEW_REQUESTED:
|
---|
1392 | case REBINDING:
|
---|
1393 | if (*message == DHCPACK) {
|
---|
1394 | temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
|
---|
1395 | if (!temp) {
|
---|
1396 | bb_error_msg("no lease time with ACK, using 1 hour lease");
|
---|
1397 | lease_seconds = 60 * 60;
|
---|
1398 | } else {
|
---|
1399 | /* it IS unaligned sometimes, don't "optimize" */
|
---|
1400 | move_from_unaligned32(lease_seconds, temp);
|
---|
1401 | lease_seconds = ntohl(lease_seconds);
|
---|
1402 | lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
|
---|
1403 | if (lease_seconds < 10) /* and not too small */
|
---|
1404 | lease_seconds = 10;
|
---|
1405 | }
|
---|
1406 | #if ENABLE_FEATURE_UDHCPC_ARPING
|
---|
1407 | if (opt & OPT_a) {
|
---|
1408 | /* RFC 2131 3.1 paragraph 5:
|
---|
1409 | * "The client receives the DHCPACK message with configuration
|
---|
1410 | * parameters. The client SHOULD perform a final check on the
|
---|
1411 | * parameters (e.g., ARP for allocated network address), and notes
|
---|
1412 | * the duration of the lease specified in the DHCPACK message. At this
|
---|
1413 | * point, the client is configured. If the client detects that the
|
---|
1414 | * address is already in use (e.g., through the use of ARP),
|
---|
1415 | * the client MUST send a DHCPDECLINE message to the server and restarts
|
---|
1416 | * the configuration process..." */
|
---|
1417 | if (!arpping(packet.yiaddr,
|
---|
1418 | NULL,
|
---|
1419 | (uint32_t) 0,
|
---|
1420 | client_config.client_mac,
|
---|
1421 | client_config.interface)
|
---|
1422 | ) {
|
---|
1423 | bb_info_msg("Offered address is in use "
|
---|
1424 | "(got ARP reply), declining");
|
---|
1425 | send_decline(xid, server_addr, packet.yiaddr);
|
---|
1426 |
|
---|
1427 | if (state != REQUESTING)
|
---|
1428 | udhcp_run_script(NULL, "deconfig");
|
---|
1429 | change_listen_mode(LISTEN_RAW);
|
---|
1430 | state = INIT_SELECTING;
|
---|
1431 | requested_ip = 0;
|
---|
1432 | timeout = tryagain_timeout;
|
---|
1433 | packet_num = 0;
|
---|
1434 | already_waited_sec = 0;
|
---|
1435 | continue; /* back to main loop */
|
---|
1436 | }
|
---|
1437 | }
|
---|
1438 | #endif
|
---|
1439 | /* enter bound state */
|
---|
1440 | timeout = lease_seconds / 2;
|
---|
1441 | {
|
---|
1442 | struct in_addr temp_addr;
|
---|
1443 | temp_addr.s_addr = packet.yiaddr;
|
---|
1444 | bb_info_msg("Lease of %s obtained, lease time %u",
|
---|
1445 | inet_ntoa(temp_addr), (unsigned)lease_seconds);
|
---|
1446 | }
|
---|
1447 | requested_ip = packet.yiaddr;
|
---|
1448 | udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
|
---|
1449 |
|
---|
1450 | state = BOUND;
|
---|
1451 | change_listen_mode(LISTEN_NONE);
|
---|
1452 | if (opt & OPT_q) { /* quit after lease */
|
---|
1453 | if (opt & OPT_R) /* release on quit */
|
---|
1454 | perform_release(requested_ip, server_addr);
|
---|
1455 | goto ret0;
|
---|
1456 | }
|
---|
1457 | /* future renew failures should not exit (JM) */
|
---|
1458 | opt &= ~OPT_n;
|
---|
1459 | #if BB_MMU /* NOMMU case backgrounded earlier */
|
---|
1460 | if (!(opt & OPT_f)) {
|
---|
1461 | client_background();
|
---|
1462 | /* do not background again! */
|
---|
1463 | opt = ((opt & ~OPT_b) | OPT_f);
|
---|
1464 | }
|
---|
1465 | #endif
|
---|
1466 | already_waited_sec = 0;
|
---|
1467 | continue; /* back to main loop */
|
---|
1468 | }
|
---|
1469 | if (*message == DHCPNAK) {
|
---|
1470 | /* return to init state */
|
---|
1471 | bb_info_msg("Received DHCP NAK");
|
---|
1472 | udhcp_run_script(&packet, "nak");
|
---|
1473 | if (state != REQUESTING)
|
---|
1474 | udhcp_run_script(NULL, "deconfig");
|
---|
1475 | change_listen_mode(LISTEN_RAW);
|
---|
1476 | sleep(3); /* avoid excessive network traffic */
|
---|
1477 | state = INIT_SELECTING;
|
---|
1478 | requested_ip = 0;
|
---|
1479 | timeout = 0;
|
---|
1480 | packet_num = 0;
|
---|
1481 | already_waited_sec = 0;
|
---|
1482 | }
|
---|
1483 | continue;
|
---|
1484 | /* case BOUND: - ignore all packets */
|
---|
1485 | /* case RELEASED: - ignore all packets */
|
---|
1486 | }
|
---|
1487 | /* back to main loop */
|
---|
1488 | } /* for (;;) - main loop ends */
|
---|
1489 |
|
---|
1490 | ret0:
|
---|
1491 | retval = 0;
|
---|
1492 | ret:
|
---|
1493 | /*if (client_config.pidfile) - remove_pidfile has its own check */
|
---|
1494 | remove_pidfile(client_config.pidfile);
|
---|
1495 | return retval;
|
---|
1496 | }
|
---|