1 | /*
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2 | * QEMU BOOTP/DHCP server
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3 | *
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4 | * Copyright (c) 2004 Fabrice Bellard
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5 | *
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6 | * Permission is hereby granted, free of charge, to any person obtaining a copy
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7 | * of this software and associated documentation files (the "Software"), to deal
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8 | * in the Software without restriction, including without limitation the rights
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9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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10 | * copies of the Software, and to permit persons to whom the Software is
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11 | * furnished to do so, subject to the following conditions:
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12 | *
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13 | * The above copyright notice and this permission notice shall be included in
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14 | * all copies or substantial portions of the Software.
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15 | *
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16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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22 | * THE SOFTWARE.
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23 | */
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24 | #include <slirp.h>
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25 |
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26 | /* XXX: only DHCP is supported */
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27 |
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28 | static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };
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29 | static void bootp_reply(PNATState pData, struct mbuf *m0, int off, uint16_t flags);
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30 |
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31 | static uint8_t *dhcp_find_option(uint8_t *vend, uint8_t tag)
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32 | {
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33 | uint8_t *q = vend;
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34 | uint8_t len;
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35 | /*@todo magic validation */
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36 | q += 4; /*magic*/
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37 | while(*q != RFC1533_END)
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38 | {
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39 | if (*q == RFC1533_PAD)
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40 | continue;
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41 | if (*q == tag)
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42 | return q;
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43 | q++;
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44 | len = *q;
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45 | q += 1 + len;
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46 | }
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47 | return NULL;
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48 | }
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49 | static BOOTPClient *alloc_addr(PNATState pData)
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50 | {
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51 | int i;
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52 | for (i = 0; i < NB_ADDR; i++)
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53 | {
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54 | if (!bootp_clients[i].allocated)
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55 | {
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56 | BOOTPClient *bc;
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57 |
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58 | bc = &bootp_clients[i];
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59 | memset(bc, 0, sizeof(BOOTPClient));
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60 | bc->allocated = 1;
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61 | bc->number = i;
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62 | return bc;
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63 | }
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64 | }
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65 | return NULL;
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66 | }
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67 | static BOOTPClient *get_new_addr(PNATState pData, struct in_addr *paddr)
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68 | {
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69 | BOOTPClient *bc;
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70 | bc = alloc_addr(pData);
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71 | if (bc == NULL)
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72 | return NULL;
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73 | paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (bc->number + START_ADDR));
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74 | bc->addr.s_addr = paddr->s_addr;
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75 | return bc;
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76 | return NULL;
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77 | }
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78 |
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79 | static int release_addr(PNATState pData, struct in_addr *paddr)
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80 | {
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81 | unsigned i;
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82 | for (i = 0; i < NB_ADDR; i++)
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83 | {
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84 | if (paddr->s_addr == bootp_clients[i].addr.s_addr)
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85 | {
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86 | memset(&bootp_clients[i], 0, sizeof(BOOTPClient));
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87 | return 1;
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88 | }
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89 | }
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90 | return 0;
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91 | }
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92 |
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93 | /*
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94 | * from RFC 2131 4.3.1
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95 | * Field DHCPOFFER DHCPACK DHCPNAK
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96 | * ----- --------- ------- -------
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97 | * 'op' BOOTREPLY BOOTREPLY BOOTREPLY
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98 | * 'htype' (From "Assigned Numbers" RFC)
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99 | * 'hlen' (Hardware address length in octets)
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100 | * 'hops' 0 0 0
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101 | * 'xid' 'xid' from client 'xid' from client 'xid' from client
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102 | * DHCPDISCOVER DHCPREQUEST DHCPREQUEST
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103 | * message message message
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104 | * 'secs' 0 0 0
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105 | * 'ciaddr' 0 'ciaddr' from 0
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106 | * DHCPREQUEST or 0
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107 | * 'yiaddr' IP address offered IP address 0
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108 | * to client assigned to client
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109 | * 'siaddr' IP address of next IP address of next 0
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110 | * bootstrap server bootstrap server
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111 | * 'flags' 'flags' from 'flags' from 'flags' from
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112 | * client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
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113 | * message message message
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114 | * 'giaddr' 'giaddr' from 'giaddr' from 'giaddr' from
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115 | * client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
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116 | * message message message
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117 | * 'chaddr' 'chaddr' from 'chaddr' from 'chaddr' from
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118 | * client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
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119 | * message message message
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120 | * 'sname' Server host name Server host name (unused)
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121 | * or options or options
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122 | * 'file' Client boot file Client boot file (unused)
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123 | * name or options name or options
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124 | * 'options' options options
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125 | *
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126 | * Option DHCPOFFER DHCPACK DHCPNAK
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127 | * ------ --------- ------- -------
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128 | * Requested IP address MUST NOT MUST NOT MUST NOT
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129 | * IP address lease time MUST MUST (DHCPREQUEST) MUST NOT
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130 | * MUST NOT (DHCPINFORM)
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131 | * Use 'file'/'sname' fields MAY MAY MUST NOT
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132 | * DHCP message type DHCPOFFER DHCPACK DHCPNAK
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133 | * Parameter request list MUST NOT MUST NOT MUST NOT
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134 | * Message SHOULD SHOULD SHOULD
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135 | * Client identifier MUST NOT MUST NOT MAY
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136 | * Vendor class identifier MAY MAY MAY
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137 | * Server identifier MUST MUST MUST
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138 | * Maximum message size MUST NOT MUST NOT MUST NOT
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139 | * All others MAY MAY MUST NOT
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140 | */
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141 | static BOOTPClient *find_addr(PNATState pData, struct in_addr *paddr, const uint8_t *macaddr)
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142 | {
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143 | int i;
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144 |
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145 | for (i = 0; i < NB_ADDR; i++)
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146 | {
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147 | if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
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148 | {
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149 | BOOTPClient *bc;
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150 |
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151 | bc = &bootp_clients[i];
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152 | bc->allocated = 1;
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153 | paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
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154 | return bc;
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155 | }
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156 | }
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157 | return NULL;
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158 | }
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159 |
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160 | static struct mbuf *dhcp_create_msg(PNATState pData, struct bootp_t *bp, struct mbuf *m, uint8_t type)
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161 | {
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162 | struct bootp_t *rbp;
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163 | struct ethhdr *eh;
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164 | uint8_t *q;
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165 |
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166 | rbp = mtod(m, struct bootp_t *);
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167 | memset(rbp, 0, sizeof(struct bootp_t));
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168 | eh = mtod(m, struct ethhdr *);
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169 | memcpy(eh->h_source, bp->bp_hwaddr, ETH_ALEN); /* XXX: if_encap just swap source with dest*/
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170 | m->m_data += if_maxlinkhdr; /*reserve ether header */
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171 | rbp = mtod(m, struct bootp_t *);
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172 | rbp->bp_op = BOOTP_REPLY;
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173 | rbp->bp_xid = bp->bp_xid; /* see table 3 of rfc2131*/
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174 | rbp->flags = bp->flags;
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175 | rbp->bp_giaddr.s_addr = bp->bp_giaddr.s_addr;
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176 | #if 0 /*check flags*/
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177 | saddr.sin_port = htons(BOOTP_SERVER);
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178 | daddr.sin_port = htons(BOOTP_CLIENT);
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179 | #endif
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180 | rbp->bp_htype = 1;
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181 | rbp->bp_hlen = 6;
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182 | memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
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183 |
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184 | memcpy(rbp->bp_vend, rfc1533_cookie, 4); /* cookie */
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185 | q = rbp->bp_vend;
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186 | q += 4;
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187 | *q++ = RFC2132_MSG_TYPE;
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188 | *q++ = 1;
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189 | *q++ = type;
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190 |
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191 | return m;
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192 | }
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193 |
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194 | static int dhcp_do_ack_offer(PNATState pData, struct mbuf *m, BOOTPClient *bc, int is_from_request)
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195 | {
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196 | int off = 0;
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197 | struct bootp_t *rbp = NULL;
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198 | uint8_t *q;
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199 | struct in_addr saddr;
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200 | int val;
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201 |
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202 | struct dns_entry *de = NULL;
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203 | struct dns_domain_entry *dd = NULL;
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204 | int added = 0;
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205 | uint8_t *q_dns_header = NULL;
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206 | uint32_t lease_time = htonl(LEASE_TIME);
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207 | uint32_t netmask = htonl(pData->netmask);
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208 |
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209 | rbp = mtod(m, struct bootp_t *);
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210 | q = &rbp->bp_vend[0];
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211 | q += 7; /* !cookie rfc 2132 + TYPE*/
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212 |
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213 | /*DHCP Offer specific*/
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214 | if ( tftp_prefix
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215 | && RTDirExists(tftp_prefix)
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216 | && bootp_filename)
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217 | RTStrPrintf((char*)rbp->bp_file, sizeof(rbp->bp_file), "%s", bootp_filename);
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218 |
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219 | Log(("NAT: DHCP: bp_file:%s\n", &rbp->bp_file));
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220 | /* Address/port of the DHCP server. */
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221 | rbp->bp_yiaddr = bc->addr; /* Client IP address */
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222 | Log(("NAT: DHCP: bp_yiaddr:%R[IP4]\n", &rbp->bp_yiaddr));
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223 | rbp->bp_siaddr = pData->tftp_server; /* Next Server IP address, i.e. TFTP */
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224 | Log(("NAT: DHCP: bp_siaddr:%R[IP4]\n", &rbp->bp_siaddr));
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225 | if (is_from_request)
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226 | {
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227 | rbp->bp_ciaddr.s_addr = bc->addr.s_addr; /* Client IP address */
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228 | }
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229 | #ifndef VBOX_WITH_NAT_SERVICE
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230 | saddr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_ALIAS);
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231 | #else
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232 | saddr.s_addr = special_addr.s_addr;
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233 | #endif
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234 | Log(("NAT: DHCP: s_addr:%R[IP4]\n", &saddr));
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235 |
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236 | #define FILL_BOOTP_EXT(q, tag, len, pvalue) \
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237 | do { \
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238 | struct bootp_ext *be = (struct bootp_ext *)(q); \
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239 | be->bpe_tag = (tag); \
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240 | be->bpe_len = (len); \
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241 | memcpy(&be[1], (pvalue), (len)); \
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242 | (q) = (uint8_t *)(&be[1]) + (len); \
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243 | }while(0)
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244 | /* appending another value to tag, calculates len of whole block*/
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245 | #define FILL_BOOTP_APP(head, q, tag, len, pvalue) \
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246 | do { \
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247 | struct bootp_ext *be = (struct bootp_ext *)(head); \
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248 | memcpy(q, (pvalue), (len)); \
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249 | (q) += (len); \
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250 | Assert(be->bpe_tag == (tag)); \
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251 | be->bpe_len += (len); \
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252 | }while(0)
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253 |
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254 |
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255 |
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256 | FILL_BOOTP_EXT(q, RFC1533_NETMASK, 4, &netmask);
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257 | FILL_BOOTP_EXT(q, RFC1533_GATEWAY, 4, &saddr);
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258 |
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259 | if (pData->use_dns_proxy)
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260 | {
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261 | uint32_t addr = htonl(ntohl(special_addr.s_addr) | CTL_DNS);
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262 | FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &addr);
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263 | goto skip_dns_servers;
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264 | }
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265 |
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266 | if (!TAILQ_EMPTY(&pData->dns_list_head))
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267 | {
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268 | de = TAILQ_LAST(&pData->dns_list_head, dns_list_head);
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269 | q_dns_header = q;
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270 | FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &de->de_addr.s_addr);
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271 | }
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272 |
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273 | TAILQ_FOREACH_REVERSE(de, &pData->dns_list_head, dns_list_head, de_list)
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274 | {
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275 | if (TAILQ_LAST(&pData->dns_list_head, dns_list_head) == de)
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276 | continue; /* first value with head we've ingected before */
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277 | FILL_BOOTP_APP(q_dns_header, q, RFC1533_DNS, 4, &de->de_addr.s_addr);
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278 | }
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279 |
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280 | skip_dns_servers:
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281 | if (LIST_EMPTY(&pData->dns_domain_list_head))
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282 | {
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283 | /* Microsoft dhcp client doen't like domain-less dhcp and trimmed packets*/
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284 | /* dhcpcd client very sad if no domain name is passed */
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285 | FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, " ");
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286 | }
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287 | if (pData->fPassDomain)
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288 | {
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289 | LIST_FOREACH(dd, &pData->dns_domain_list_head, dd_list)
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290 | {
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291 |
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292 | if (dd->dd_pszDomain == NULL)
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293 | continue;
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294 | /* never meet valid separator here in RFC1533*/
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295 | if (added != 0)
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296 | FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, ",");
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297 | else
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298 | added = 1;
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299 | val = (int)strlen(dd->dd_pszDomain);
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300 | FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, val, dd->dd_pszDomain);
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301 | }
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302 | }
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303 |
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304 | FILL_BOOTP_EXT(q, RFC2132_LEASE_TIME, 4, &lease_time);
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305 |
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306 | if (*slirp_hostname)
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307 | {
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308 | val = (int)strlen(slirp_hostname);
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309 | FILL_BOOTP_EXT(q, RFC1533_HOSTNAME, val, slirp_hostname);
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310 | }
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311 | return q - rbp->bp_vend; /*return offset */
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312 | }
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313 |
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314 | static int dhcp_send_nack(PNATState pData, struct bootp_t *bp, BOOTPClient *bc, struct mbuf *m)
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315 | {
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316 | struct bootp_t *rbp;
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317 | uint8_t *q = NULL;
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318 | rbp = mtod(m, struct bootp_t *);
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319 |
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320 | dhcp_create_msg(pData, bp, m, DHCPNAK);
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321 |
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322 | return 7;
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323 | }
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324 | static int dhcp_send_ack(PNATState pData, struct bootp_t *bp, BOOTPClient *bc, struct mbuf *m, int is_from_request)
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325 | {
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326 | struct bootp_t *rbp;
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327 | int off = 0; /* boot_reply will fill general options and add END before sending response*/
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328 |
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329 | dhcp_create_msg(pData, bp, m, DHCPACK);
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330 | off = dhcp_do_ack_offer(pData, m, bc, is_from_request);
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331 | return off;
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332 | }
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333 | static int dhcp_send_offer(PNATState pData, struct bootp_t *bp, BOOTPClient *bc, struct mbuf *m)
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334 | {
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335 | struct bootp_t *rbp;
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336 | int off = 0; /* boot_reply will fill general options and add END before sending response*/
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337 |
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338 | dhcp_create_msg(pData, bp, m, DHCPOFFER);
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339 | off = dhcp_do_ack_offer(pData, m, bc, 0);
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340 | return off;
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341 | }
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342 |
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343 | /**
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344 | * decoding client messages RFC2131 (4.3.6)
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345 | * ---------------------------------------------------------------------
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346 | * | |INIT-REBOOT |SELECTING |RENEWING |REBINDING |
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347 | * ---------------------------------------------------------------------
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348 | * |broad/unicast |broadcast |broadcast |unicast |broadcast |
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349 | * |server-ip |MUST NOT |MUST |MUST NOT |MUST NOT |
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350 | * |requested-ip |MUST |MUST |MUST NOT |MUST NOT |
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351 | * |ciaddr |zero |zero |IP address |IP address|
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352 | * ---------------------------------------------------------------------
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353 | *
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354 | */
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355 | enum DHCP_REQUEST_STATES{INIT_REBOOT, SELECTING, RENEWING, REBINDING, NONE};
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356 | static int dhcp_decode_request(PNATState pData, struct bootp_t *bp, const uint8_t *buf, int size, struct mbuf *m)
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357 | {
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358 | BOOTPClient *bc;
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359 | struct in_addr daddr;
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360 | int off;
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361 | uint8_t *opt;
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362 | uint8_t *req_ip;
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363 | uint8_t *server_ip;
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364 | enum DHCP_REQUEST_STATES dhcp_stat = NONE;
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365 | /*need to understand which type of request we get */
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366 | req_ip = dhcp_find_option(&bp->bp_vend[0], RFC2132_REQ_ADDR);
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367 | server_ip = dhcp_find_option(&bp->bp_vend[0], RFC2132_SRV_ID);
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368 |
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369 | bc = find_addr(pData, &daddr, bp->bp_hwaddr);
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370 | if (!bc)
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371 | {
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372 | LogRel(("NAT: DHCP no IP address left\n"));
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373 | Log(("no address left\n"));
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374 | return -1;
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375 | }
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376 | LogRel(("NAT: flags:%x sec:%x\n", bp->flags, bp->bp_secs));
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377 | if (server_ip != NULL)
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378 | {
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379 | /*selecting*/
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380 | dhcp_stat = SELECTING;
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381 | Assert((bp->bp_ciaddr.s_addr == INADDR_ANY));
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382 | Assert((*(uint32_t *)(req_ip + 2) == bc->addr.s_addr)); /*the same address as in offer*/
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383 | Assert((bp->bp_xid == bc->xid));
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384 | }
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385 | else
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386 | {
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387 | if (req_ip != NULL)
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388 | {
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389 | /* init-reboot */
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390 | dhcp_stat = INIT_REBOOT;
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391 | }
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392 | else
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393 | {
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394 | if (bp->flags & DHCP_FLAGS_B)
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395 | dhcp_stat = RENEWING;
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396 | else
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397 | dhcp_stat = REBINDING; /*??rebinding??*/
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398 | }
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399 | }
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400 | /*?? renewing ??*/
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401 | if(dhcp_stat == RENEWING){
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402 | Assert(( server_ip == NULL
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403 | && req_ip == NULL
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404 | && bp->bp_ciaddr.s_addr != INADDR_ANY));
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405 | if (bc != NULL)
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406 | {
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407 | Assert((bc->addr.s_addr == bp->bp_ciaddr.s_addr));
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408 | /*if it already here well just do ack, we aren't aware of dhcp time expiration*/
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409 | }
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410 | else
|
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411 | {
|
---|
412 | if ((bp->bp_ciaddr.s_addr & pData->netmask) != special_addr.s_addr)
|
---|
413 | {
|
---|
414 | off = dhcp_send_nack(pData, bp, bc, m);
|
---|
415 | return off;
|
---|
416 | }
|
---|
417 | bc = alloc_addr(pData);
|
---|
418 | if (bc == NULL)
|
---|
419 | {
|
---|
420 | LogRel(("NAT: can't alloc address. RENEW has been silently ignored\n"));
|
---|
421 | return -1;
|
---|
422 | }
|
---|
423 | Assert((bp->bp_hlen == ETH_ALEN));
|
---|
424 | memcpy(bc->macaddr, bp->bp_hwaddr, bp->bp_hlen);
|
---|
425 | bc->addr.s_addr = bp->bp_ciaddr.s_addr; /* @todo change releasing */
|
---|
426 | }
|
---|
427 | }
|
---|
428 | Assert((dhcp_stat != NONE));
|
---|
429 | off = dhcp_send_ack(pData, bp, bc, m, 1);/*@todo when need send NACK */
|
---|
430 | return off;
|
---|
431 | }
|
---|
432 |
|
---|
433 | static int dhcp_decode_discover(PNATState pData, struct bootp_t *bp, const uint8_t *buf, int size, int flag, struct mbuf *m)
|
---|
434 | {
|
---|
435 | BOOTPClient *bc;
|
---|
436 | struct in_addr daddr;
|
---|
437 | int off;
|
---|
438 | /* flag == 1 discover */
|
---|
439 | if (flag == 1)
|
---|
440 | {
|
---|
441 | bc = find_addr(pData, &daddr, bp->bp_hwaddr);
|
---|
442 | if (!bc)
|
---|
443 | {
|
---|
444 | bc = get_new_addr(pData, &daddr);
|
---|
445 | if (!bc)
|
---|
446 | {
|
---|
447 | LogRel(("NAT: DHCP no IP address left\n"));
|
---|
448 | Log(("no address left\n"));
|
---|
449 | return -1;
|
---|
450 | }
|
---|
451 | memcpy(bc->macaddr, bp->bp_hwaddr, 6);
|
---|
452 | }
|
---|
453 | bc->xid = bp->bp_xid;
|
---|
454 | /*bc isn't NULL */
|
---|
455 | off = dhcp_send_offer(pData, bp, bc, m);
|
---|
456 | return off;
|
---|
457 | }
|
---|
458 | else
|
---|
459 | {
|
---|
460 | /* flag == 0 inform */
|
---|
461 | bc = find_addr(pData, &daddr, bp->bp_hwaddr);
|
---|
462 | if (bc == NULL)
|
---|
463 | {
|
---|
464 | LogRel(("NAT: DHCP Inform was ignored no boot client was found\n"));
|
---|
465 | return -1;
|
---|
466 | }
|
---|
467 | off = dhcp_send_ack(pData, bp, bc, m, 0);
|
---|
468 | return off;
|
---|
469 | }
|
---|
470 | return -1;
|
---|
471 | }
|
---|
472 |
|
---|
473 | static int dhcp_decode_release(PNATState pData, struct bootp_t *bp, const uint8_t *buf, int size, int flag)
|
---|
474 | {
|
---|
475 | return -1;
|
---|
476 | }
|
---|
477 | /**
|
---|
478 | * fields for discovering t
|
---|
479 | * Field DHCPDISCOVER DHCPREQUEST DHCPDECLINE,
|
---|
480 | * DHCPINFORM DHCPRELEASE
|
---|
481 | * ----- ------------ ----------- -----------
|
---|
482 | * 'op' BOOTREQUEST BOOTREQUEST BOOTREQUEST
|
---|
483 | * 'htype' (From "Assigned Numbers" RFC)
|
---|
484 | * 'hlen' (Hardware address length in octets)
|
---|
485 | * 'hops' 0 0 0
|
---|
486 | * 'xid' selected by client 'xid' from server selected by
|
---|
487 | * DHCPOFFER message client
|
---|
488 | * 'secs' 0 or seconds since 0 or seconds since 0
|
---|
489 | * DHCP process started DHCP process started
|
---|
490 | * 'flags' Set 'BROADCAST' Set 'BROADCAST' 0
|
---|
491 | * flag if client flag if client
|
---|
492 | * requires broadcast requires broadcast
|
---|
493 | * reply reply
|
---|
494 | * 'ciaddr' 0 (DHCPDISCOVER) 0 or client's 0 (DHCPDECLINE)
|
---|
495 | * client's network address client's network
|
---|
496 | * network address (BOUND/RENEW/REBIND) address
|
---|
497 | * (DHCPINFORM) (DHCPRELEASE)
|
---|
498 | * 'yiaddr' 0 0 0
|
---|
499 | * 'siaddr' 0 0 0
|
---|
500 | * 'giaddr' 0 0 0
|
---|
501 | * 'chaddr' client's hardware client's hardware client's hardware
|
---|
502 | * address address address
|
---|
503 | * 'sname' options, if options, if (unused)
|
---|
504 | * indicated in indicated in
|
---|
505 | * 'sname/file' 'sname/file'
|
---|
506 | * option; otherwise option; otherwise
|
---|
507 | * unused unused
|
---|
508 | * 'file' options, if options, if (unused)
|
---|
509 | * indicated in indicated in
|
---|
510 | * 'sname/file' 'sname/file'
|
---|
511 | * option; otherwise option; otherwise
|
---|
512 | * unused unused
|
---|
513 | * 'options' options options (unused)
|
---|
514 | * Requested IP address MAY MUST (in MUST
|
---|
515 | * (DISCOVER) SELECTING or (DHCPDECLINE),
|
---|
516 | * MUST NOT INIT-REBOOT) MUST NOT
|
---|
517 | * (INFORM) MUST NOT (in (DHCPRELEASE)
|
---|
518 | * BOUND or
|
---|
519 | * RENEWING)
|
---|
520 | * IP address lease time MAY MAY MUST NOT
|
---|
521 | * (DISCOVER)
|
---|
522 | * MUST NOT
|
---|
523 | * (INFORM)
|
---|
524 | * Use 'file'/'sname' fields MAY MAY MAY
|
---|
525 | * DHCP message type DHCPDISCOVER/ DHCPREQUEST DHCPDECLINE/
|
---|
526 | * DHCPINFORM DHCPRELEASE
|
---|
527 | * Client identifier MAY MAY MAY
|
---|
528 | * Vendor class identifier MAY MAY MUST NOT
|
---|
529 | * Server identifier MUST NOT MUST (after MUST
|
---|
530 | * SELECTING)
|
---|
531 | * MUST NOT (after
|
---|
532 | * INIT-REBOOT,
|
---|
533 | * BOUND, RENEWING
|
---|
534 | * or REBINDING)
|
---|
535 | * Parameter request list MAY MAY MUST NOT
|
---|
536 | * Maximum message size MAY MAY MUST NOT
|
---|
537 | * Message SHOULD NOT SHOULD NOT SHOULD
|
---|
538 | * Site-specific MAY MAY MUST NOT
|
---|
539 | * All others MAY MAY MUST NOT
|
---|
540 | *
|
---|
541 | */
|
---|
542 | static void dhcp_decode(PNATState pData, struct bootp_t *bp, const uint8_t *buf, int size)
|
---|
543 | {
|
---|
544 | const uint8_t *p, *p_end;
|
---|
545 | int rc;
|
---|
546 | int pmsg_type;
|
---|
547 | struct in_addr req_ip;
|
---|
548 | int flag = 0;
|
---|
549 | int len, tag;
|
---|
550 | struct mbuf *m = NULL;
|
---|
551 |
|
---|
552 | pmsg_type = 0;
|
---|
553 |
|
---|
554 | p = buf;
|
---|
555 | p_end = buf + size;
|
---|
556 | if (size < 5)
|
---|
557 | return;
|
---|
558 | if (memcmp(p, rfc1533_cookie, 4) != 0)
|
---|
559 | return;
|
---|
560 | p = dhcp_find_option(bp->bp_vend, RFC2132_MSG_TYPE);
|
---|
561 | Assert(p);
|
---|
562 | if (p == NULL)
|
---|
563 | return;
|
---|
564 | if ((m = m_get(pData)) == NULL)
|
---|
565 | {
|
---|
566 | LogRel(("NAT: can't alocate memory for response!\n"));
|
---|
567 | return;
|
---|
568 | }
|
---|
569 | switch(*(p+2))
|
---|
570 | {
|
---|
571 | case DHCPDISCOVER:
|
---|
572 | flag = 1;
|
---|
573 | /**/
|
---|
574 | case DHCPINFORM:
|
---|
575 | rc = dhcp_decode_discover(pData, bp, buf, size, flag, m);
|
---|
576 | Assert(rc > 0);
|
---|
577 | goto reply;
|
---|
578 | break;
|
---|
579 | case DHCPREQUEST:
|
---|
580 | rc = dhcp_decode_request(pData, bp, buf, size, m);
|
---|
581 | Assert(rc > 0);
|
---|
582 | goto reply;
|
---|
583 | break;
|
---|
584 | case DHCPRELEASE:
|
---|
585 | flag = 1;
|
---|
586 | #if 0
|
---|
587 | case DHCPDECLINE:
|
---|
588 | #endif
|
---|
589 | rc = dhcp_decode_release(pData, bp, buf, size, flag);
|
---|
590 | Assert(rc > 0);
|
---|
591 | goto reply;
|
---|
592 | break;
|
---|
593 | default:
|
---|
594 | AssertMsgFailed(("unsupported DHCP message type"));
|
---|
595 | }
|
---|
596 | return;
|
---|
597 | reply:
|
---|
598 | Assert(m);
|
---|
599 | if (rc < 0)
|
---|
600 | {
|
---|
601 | /*silently ignore*/
|
---|
602 | m_free(pData, m);
|
---|
603 | return;
|
---|
604 | }
|
---|
605 | bootp_reply(pData, m, rc, bp->flags);
|
---|
606 | return;
|
---|
607 | }
|
---|
608 |
|
---|
609 | static void bootp_reply(PNATState pData, struct mbuf *m, int off, uint16_t flags)
|
---|
610 | {
|
---|
611 | #if 0
|
---|
612 | BOOTPClient *bc;
|
---|
613 | struct mbuf *m; /* XXX: @todo vasily - it'd be better to reuse this mbuf here */
|
---|
614 | struct bootp_t *bp = mtod(m0, struct bootp_t *);
|
---|
615 | struct bootp_t *rbp;
|
---|
616 | struct sockaddr_in saddr, daddr;
|
---|
617 | int dhcp_msg_type, val;
|
---|
618 | uint8_t *q;
|
---|
619 | struct in_addr requested_ip; /* the requested IP in DHCPREQUEST */
|
---|
620 | int send_nak = 0;
|
---|
621 |
|
---|
622 | /* extract exact DHCP msg type */
|
---|
623 | requested_ip.s_addr = 0xffffffff;
|
---|
624 | dhcp_decode(bp, bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type, &requested_ip);
|
---|
625 | Log(("bootp packet op=%d msgtype=%d\n", bp->bp_op, dhcp_msg_type));
|
---|
626 |
|
---|
627 | if (dhcp_msg_type == 0)
|
---|
628 | dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
|
---|
629 |
|
---|
630 | if (dhcp_msg_type == DHCPRELEASE)
|
---|
631 | {
|
---|
632 | int rc;
|
---|
633 | rc = release_addr(pData, &bp->bp_ciaddr);
|
---|
634 | LogRel(("NAT: %s %R[IP4]\n",
|
---|
635 | rc ? "DHCP released IP address" : "Ignored DHCP release for IP address",
|
---|
636 | &bp->bp_ciaddr));
|
---|
637 | /* This message is not to be answered in any way. */
|
---|
638 | return;
|
---|
639 | }
|
---|
640 | if ( dhcp_msg_type != DHCPDISCOVER
|
---|
641 | && dhcp_msg_type != DHCPREQUEST)
|
---|
642 | return;
|
---|
643 |
|
---|
644 |
|
---|
645 | if (dhcp_msg_type == DHCPDISCOVER)
|
---|
646 | {
|
---|
647 | /* Do not allocate a new lease for clients that forgot that they had a lease. */
|
---|
648 | }
|
---|
649 | else if (dhcp_msg_type == DHCPREQUEST)
|
---|
650 | {
|
---|
651 | *q++ = RFC2132_MSG_TYPE;
|
---|
652 | *q++ = 1;
|
---|
653 | if (requested_ip.s_addr != daddr.sin_addr.s_addr)
|
---|
654 | {
|
---|
655 | /* network changed */
|
---|
656 | *q++ = DHCPNAK;
|
---|
657 | send_nak = 1;
|
---|
658 | }
|
---|
659 | else
|
---|
660 | *q++ = DHCPACK;
|
---|
661 | }
|
---|
662 |
|
---|
663 | if (send_nak)
|
---|
664 | LogRel(("NAT: Client requested IP address %R[IP4] -- sending NAK\n",
|
---|
665 | &requested_ip));
|
---|
666 | else
|
---|
667 | LogRel(("NAT: DHCP offered IP address %R[IP4]\n",
|
---|
668 | &daddr.sin_addr));
|
---|
669 | if ( dhcp_msg_type == DHCPDISCOVER
|
---|
670 | || dhcp_msg_type == DHCPREQUEST)
|
---|
671 | {
|
---|
672 | FILL_BOOTP_EXT(q, RFC2132_SRV_ID, 4, &saddr.sin_addr);
|
---|
673 | }
|
---|
674 |
|
---|
675 | if (!send_nak &&
|
---|
676 | ( dhcp_msg_type == DHCPDISCOVER
|
---|
677 | || dhcp_msg_type == DHCPREQUEST))
|
---|
678 | #endif
|
---|
679 | struct sockaddr_in saddr, daddr;
|
---|
680 | struct bootp_t *rbp = NULL;
|
---|
681 | uint8_t *q = NULL;
|
---|
682 | int nack;
|
---|
683 | rbp = mtod(m, struct bootp_t *);
|
---|
684 | Assert((m));
|
---|
685 | Assert((rbp));
|
---|
686 | q = rbp->bp_vend;
|
---|
687 | nack = (q[6] == DHCPNAK);
|
---|
688 | q += off;
|
---|
689 |
|
---|
690 | #ifndef VBOX_WITH_NAT_SERVICE
|
---|
691 | saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_ALIAS);
|
---|
692 | #else
|
---|
693 | saddr.sin_addr.s_addr = special_addr.s_addr;
|
---|
694 | #endif
|
---|
695 |
|
---|
696 | FILL_BOOTP_EXT(q, RFC2132_SRV_ID, 4, &saddr.sin_addr);
|
---|
697 |
|
---|
698 |
|
---|
699 | *q++ = RFC1533_END; /*end of message */
|
---|
700 |
|
---|
701 |
|
---|
702 | m->m_len = sizeof(struct bootp_t)
|
---|
703 | - sizeof(struct ip)
|
---|
704 | - sizeof(struct udphdr);
|
---|
705 | m->m_data += sizeof(struct udphdr)
|
---|
706 | + sizeof(struct ip);
|
---|
707 | if ((flags & DHCP_FLAGS_B) || nack != 0)
|
---|
708 | daddr.sin_addr.s_addr = INADDR_BROADCAST;
|
---|
709 | else
|
---|
710 | daddr.sin_addr.s_addr = rbp->bp_yiaddr.s_addr; /*unicast requested by client*/
|
---|
711 | saddr.sin_port = htons(BOOTP_SERVER);
|
---|
712 | daddr.sin_port = htons(BOOTP_CLIENT);
|
---|
713 | udp_output2(pData, NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
|
---|
714 | }
|
---|
715 |
|
---|
716 | void bootp_input(PNATState pData, struct mbuf *m)
|
---|
717 | {
|
---|
718 | struct bootp_t *bp = mtod(m, struct bootp_t *);
|
---|
719 |
|
---|
720 | if (bp->bp_op == BOOTP_REQUEST)
|
---|
721 | {
|
---|
722 | dhcp_decode(pData, bp, bp->bp_vend, DHCP_OPT_LEN);
|
---|
723 | }
|
---|
724 | }
|
---|