| 1 | /* $Id: DhcpMessage.cpp 76553 2019-01-01 01:45:53Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * DHCP Message and its de/serialization.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2017-2019 Oracle Corporation
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | * available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | * you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | * General Public License (GPL) as published by the Free Software
|
|---|
| 13 | * Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 14 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 15 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | */
|
|---|
| 17 |
|
|---|
| 18 | #include "DhcpMessage.h"
|
|---|
| 19 | #include "DhcpOptions.h"
|
|---|
| 20 |
|
|---|
| 21 | #include <iprt/string.h>
|
|---|
| 22 | #include <iprt/stream.h>
|
|---|
| 23 |
|
|---|
| 24 |
|
|---|
| 25 |
|
|---|
| 26 | DhcpMessage::DhcpMessage()
|
|---|
| 27 | : m_xid(0), m_flags(0),
|
|---|
| 28 | m_ciaddr(), m_yiaddr(), m_siaddr(), m_giaddr(),
|
|---|
| 29 | m_sname(), m_file(),
|
|---|
| 30 | m_optMessageType()
|
|---|
| 31 | {
|
|---|
| 32 | }
|
|---|
| 33 |
|
|---|
| 34 |
|
|---|
| 35 | /* static */
|
|---|
| 36 | DhcpClientMessage *DhcpClientMessage::parse(bool broadcasted, const void *buf, size_t buflen)
|
|---|
| 37 | {
|
|---|
| 38 | if (buflen < RT_OFFSETOF(RTNETBOOTP, bp_vend.Dhcp.dhcp_opts))
|
|---|
| 39 | {
|
|---|
| 40 | RTPrintf("%s: %zu bytes datagram is too short\n", __FUNCTION__, buflen);
|
|---|
| 41 | return NULL;
|
|---|
| 42 | }
|
|---|
| 43 |
|
|---|
| 44 | PCRTNETBOOTP bp = (PCRTNETBOOTP)buf;
|
|---|
| 45 |
|
|---|
| 46 | if (bp->bp_op != RTNETBOOTP_OP_REQUEST)
|
|---|
| 47 | {
|
|---|
| 48 | RTPrintf("%s: bad opcode: %d\n", __FUNCTION__, bp->bp_op);
|
|---|
| 49 | return NULL;
|
|---|
| 50 | }
|
|---|
| 51 |
|
|---|
| 52 | if (bp->bp_htype != RTNET_ARP_ETHER)
|
|---|
| 53 | {
|
|---|
| 54 | RTPrintf("%s: unsupported htype %d\n", __FUNCTION__, bp->bp_htype);
|
|---|
| 55 | return NULL;
|
|---|
| 56 | }
|
|---|
| 57 |
|
|---|
| 58 | if (bp->bp_hlen != sizeof(RTMAC))
|
|---|
| 59 | {
|
|---|
| 60 | RTPrintf("%s: unexpected hlen %d\n", __FUNCTION__, bp->bp_hlen);
|
|---|
| 61 | return NULL;
|
|---|
| 62 | }
|
|---|
| 63 |
|
|---|
| 64 | if ( (bp->bp_chaddr.Mac.au8[0] & 0x01) != 0
|
|---|
| 65 | && (bp->bp_flags & RTNET_DHCP_FLAG_BROADCAST) == 0)
|
|---|
| 66 | {
|
|---|
| 67 | RTPrintf("%s: multicast chaddr %RTmac without broadcast flag\n",
|
|---|
| 68 | __FUNCTION__, &bp->bp_chaddr.Mac);
|
|---|
| 69 | }
|
|---|
| 70 |
|
|---|
| 71 | /* we don't want to deal with forwarding */
|
|---|
| 72 | if (bp->bp_giaddr.u != 0)
|
|---|
| 73 | {
|
|---|
| 74 | RTPrintf("%s: giaddr %RTnaipv4\n", __FUNCTION__, bp->bp_giaddr.u);
|
|---|
| 75 | return NULL;
|
|---|
| 76 | }
|
|---|
| 77 |
|
|---|
| 78 | if (bp->bp_hops != 0)
|
|---|
| 79 | {
|
|---|
| 80 | RTPrintf("%s: non-zero hops %d\n", __FUNCTION__, bp->bp_hops);
|
|---|
| 81 | return NULL;
|
|---|
| 82 | }
|
|---|
| 83 |
|
|---|
| 84 | std::unique_ptr<DhcpClientMessage> msg(new DhcpClientMessage());
|
|---|
| 85 |
|
|---|
| 86 | msg->m_broadcasted = broadcasted;
|
|---|
| 87 |
|
|---|
| 88 | msg->m_xid = bp->bp_xid;
|
|---|
| 89 | msg->m_flags = bp->bp_flags;
|
|---|
| 90 |
|
|---|
| 91 | msg->m_mac = bp->bp_chaddr.Mac;
|
|---|
| 92 |
|
|---|
| 93 | msg->m_ciaddr = bp->bp_ciaddr;
|
|---|
| 94 | msg->m_yiaddr = bp->bp_yiaddr;
|
|---|
| 95 | msg->m_siaddr = bp->bp_siaddr;
|
|---|
| 96 | msg->m_giaddr = bp->bp_giaddr;
|
|---|
| 97 |
|
|---|
| 98 | if (bp->bp_vend.Dhcp.dhcp_cookie != RT_H2N_U32_C(RTNET_DHCP_COOKIE))
|
|---|
| 99 | {
|
|---|
| 100 | RTPrintf("bad cookie\n");
|
|---|
| 101 | return NULL;
|
|---|
| 102 | }
|
|---|
| 103 |
|
|---|
| 104 | int overload;
|
|---|
| 105 | overload = msg->parseOptions(&bp->bp_vend.Dhcp.dhcp_opts,
|
|---|
| 106 | buflen - RT_OFFSETOF(RTNETBOOTP, bp_vend.Dhcp.dhcp_opts));
|
|---|
| 107 | if (overload < 0)
|
|---|
| 108 | return NULL;
|
|---|
| 109 |
|
|---|
| 110 | /* "The 'file' field MUST be interpreted next ..." */
|
|---|
| 111 | if (overload & DHCP_OPTION_OVERLOAD_FILE) {
|
|---|
| 112 | int status = msg->parseOptions(bp->bp_file, sizeof(bp->bp_file));
|
|---|
| 113 | if (status != 0)
|
|---|
| 114 | return NULL;
|
|---|
| 115 | }
|
|---|
| 116 | else if (bp->bp_file[0] != '\0')
|
|---|
| 117 | {
|
|---|
| 118 | /* must be zero terminated, ignore if not */
|
|---|
| 119 | const char *pszFile = (const char *)bp->bp_file;
|
|---|
| 120 | size_t len = RTStrNLen(pszFile, sizeof(bp->bp_file));
|
|---|
| 121 | if (len < sizeof(bp->bp_file))
|
|---|
| 122 | msg->m_file.assign(pszFile, len);
|
|---|
| 123 | }
|
|---|
| 124 |
|
|---|
| 125 | /* "... followed by the 'sname' field." */
|
|---|
| 126 | if (overload & DHCP_OPTION_OVERLOAD_SNAME) {
|
|---|
| 127 | int status = msg->parseOptions(bp->bp_sname, sizeof(bp->bp_sname));
|
|---|
| 128 | if (status != 0) /* NB: this includes "nested" Option Overload */
|
|---|
| 129 | return NULL;
|
|---|
| 130 | }
|
|---|
| 131 | else if (bp->bp_sname[0] != '\0')
|
|---|
| 132 | {
|
|---|
| 133 | /* must be zero terminated, ignore if not */
|
|---|
| 134 | const char *pszSName = (const char *)bp->bp_sname;
|
|---|
| 135 | size_t len = RTStrNLen(pszSName, sizeof(bp->bp_sname));
|
|---|
| 136 | if (len < sizeof(bp->bp_sname))
|
|---|
| 137 | msg->m_sname.assign(pszSName, len);
|
|---|
| 138 | }
|
|---|
| 139 |
|
|---|
| 140 | msg->m_optMessageType = OptMessageType(*msg);
|
|---|
| 141 | if (!msg->m_optMessageType.present())
|
|---|
| 142 | return NULL;
|
|---|
| 143 |
|
|---|
| 144 | msg->m_id = ClientId(msg->m_mac, OptClientId(*msg));
|
|---|
| 145 |
|
|---|
| 146 | return msg.release();
|
|---|
| 147 | }
|
|---|
| 148 |
|
|---|
| 149 |
|
|---|
| 150 | int DhcpClientMessage::parseOptions(const void *buf, size_t buflen)
|
|---|
| 151 | {
|
|---|
| 152 | uint8_t opt, optlen;
|
|---|
| 153 | const uint8_t *data;
|
|---|
| 154 | int overload;
|
|---|
| 155 |
|
|---|
| 156 | overload = 0;
|
|---|
| 157 |
|
|---|
| 158 | data = static_cast<const uint8_t *>(buf);
|
|---|
| 159 | while (buflen > 0) {
|
|---|
| 160 | opt = *data++;
|
|---|
| 161 | --buflen;
|
|---|
| 162 |
|
|---|
| 163 | if (opt == RTNET_DHCP_OPT_PAD) {
|
|---|
| 164 | continue;
|
|---|
| 165 | }
|
|---|
| 166 |
|
|---|
| 167 | if (opt == RTNET_DHCP_OPT_END) {
|
|---|
| 168 | break;
|
|---|
| 169 | }
|
|---|
| 170 |
|
|---|
| 171 | if (buflen == 0) {
|
|---|
| 172 | RTPrintf("option %d has no length field\n", opt);
|
|---|
| 173 | return -1;
|
|---|
| 174 | }
|
|---|
| 175 |
|
|---|
| 176 | optlen = *data++;
|
|---|
| 177 | --buflen;
|
|---|
| 178 |
|
|---|
| 179 | if (optlen > buflen) {
|
|---|
| 180 | RTPrintf("option %d truncated (length %d, but only %lu bytes left)\n",
|
|---|
| 181 | opt, optlen, (unsigned long)buflen);
|
|---|
| 182 | return -1;
|
|---|
| 183 | }
|
|---|
| 184 |
|
|---|
| 185 | #if 0
|
|---|
| 186 | rawopts_t::const_iterator it(m_optmap.find(opt));
|
|---|
| 187 | if (it != m_optmap.cend())
|
|---|
| 188 | return -1;
|
|---|
| 189 | #endif
|
|---|
| 190 | if (opt == RTNET_DHCP_OPT_OPTION_OVERLOAD) {
|
|---|
| 191 | if (optlen != 1) {
|
|---|
| 192 | RTPrintf("Overload Option (option %d) has invalid length %d\n",
|
|---|
| 193 | opt, optlen);
|
|---|
| 194 | return -1;
|
|---|
| 195 | }
|
|---|
| 196 |
|
|---|
| 197 | overload = *data;
|
|---|
| 198 |
|
|---|
| 199 | if ((overload & ~DHCP_OPTION_OVERLOAD_MASK) != 0) {
|
|---|
| 200 | RTPrintf("Overload Option (option %d) has invalid value 0x%x\n",
|
|---|
| 201 | opt, overload);
|
|---|
| 202 | return -1;
|
|---|
| 203 | }
|
|---|
| 204 | }
|
|---|
| 205 | else
|
|---|
| 206 | {
|
|---|
| 207 | m_rawopts.insert(std::make_pair(opt, octets_t(data, data + optlen)));
|
|---|
| 208 | }
|
|---|
| 209 |
|
|---|
| 210 | data += optlen;
|
|---|
| 211 | buflen -= optlen;
|
|---|
| 212 | }
|
|---|
| 213 |
|
|---|
| 214 | return overload;
|
|---|
| 215 | }
|
|---|
| 216 |
|
|---|
| 217 |
|
|---|
| 218 | void DhcpClientMessage::dump() const
|
|---|
| 219 | {
|
|---|
| 220 | switch (m_optMessageType.value())
|
|---|
| 221 | {
|
|---|
| 222 | case RTNET_DHCP_MT_DISCOVER:
|
|---|
| 223 | LogDHCP(("DISCOVER"));
|
|---|
| 224 | break;
|
|---|
| 225 |
|
|---|
| 226 | case RTNET_DHCP_MT_REQUEST:
|
|---|
| 227 | LogDHCP(("REQUEST"));
|
|---|
| 228 | break;
|
|---|
| 229 |
|
|---|
| 230 | case RTNET_DHCP_MT_INFORM:
|
|---|
| 231 | LogDHCP(("INFORM"));
|
|---|
| 232 | break;
|
|---|
| 233 |
|
|---|
| 234 | case RTNET_DHCP_MT_DECLINE:
|
|---|
| 235 | LogDHCP(("DECLINE"));
|
|---|
| 236 | break;
|
|---|
| 237 |
|
|---|
| 238 | case RTNET_DHCP_MT_RELEASE:
|
|---|
| 239 | LogDHCP(("RELEASE"));
|
|---|
| 240 | break;
|
|---|
| 241 |
|
|---|
| 242 | default:
|
|---|
| 243 | LogDHCP(("<Unknown Mesage Type %d>", m_optMessageType.value()));
|
|---|
| 244 | break;
|
|---|
| 245 | }
|
|---|
| 246 |
|
|---|
| 247 | if (OptRapidCommit(*this).present())
|
|---|
| 248 | LogDHCP((" (rapid commit)"));
|
|---|
| 249 |
|
|---|
| 250 |
|
|---|
| 251 | const OptServerId sid(*this);
|
|---|
| 252 | if (sid.present())
|
|---|
| 253 | LogDHCP((" for server %RTnaipv4", sid.value().u));
|
|---|
| 254 |
|
|---|
| 255 | LogDHCP((" xid 0x%08x", m_xid));
|
|---|
| 256 | LogDHCP((" chaddr %RTmac\n", &m_mac));
|
|---|
| 257 |
|
|---|
| 258 | const OptClientId cid(*this);
|
|---|
| 259 | if (cid.present()) {
|
|---|
| 260 | if (cid.value().size() > 0)
|
|---|
| 261 | LogDHCP((" client id: %.*Rhxs\n", cid.value().size(), &cid.value().front()));
|
|---|
| 262 | else
|
|---|
| 263 | LogDHCP((" client id: <empty>\n"));
|
|---|
| 264 | }
|
|---|
| 265 |
|
|---|
| 266 | LogDHCP((" ciaddr %RTnaipv4", m_ciaddr.u));
|
|---|
| 267 | if (m_yiaddr.u != 0)
|
|---|
| 268 | LogDHCP((" yiaddr %RTnaipv4", m_yiaddr.u));
|
|---|
| 269 | if (m_siaddr.u != 0)
|
|---|
| 270 | LogDHCP((" siaddr %RTnaipv4", m_siaddr.u));
|
|---|
| 271 | if (m_giaddr.u != 0)
|
|---|
| 272 | LogDHCP((" giaddr %RTnaipv4", m_giaddr.u));
|
|---|
| 273 | LogDHCP(("%s\n", broadcast() ? "broadcast" : ""));
|
|---|
| 274 |
|
|---|
| 275 |
|
|---|
| 276 | const OptRequestedAddress reqAddr(*this);
|
|---|
| 277 | if (reqAddr.present())
|
|---|
| 278 | LogDHCP((" requested address %RTnaipv4", reqAddr.value().u));
|
|---|
| 279 | const OptLeaseTime reqLeaseTime(*this);
|
|---|
| 280 | if (reqLeaseTime.present())
|
|---|
| 281 | LogDHCP((" requested lease time %d", reqAddr.value()));
|
|---|
| 282 | if (reqAddr.present() || reqLeaseTime.present())
|
|---|
| 283 | LogDHCP(("\n"));
|
|---|
| 284 |
|
|---|
| 285 | const OptParameterRequest params(*this);
|
|---|
| 286 | if (params.present())
|
|---|
| 287 | {
|
|---|
| 288 | LogDHCP((" params {"));
|
|---|
| 289 | typedef OptParameterRequest::value_t::const_iterator it_t;
|
|---|
| 290 | for (it_t it = params.value().begin(); it != params.value().end(); ++it)
|
|---|
| 291 | LogDHCP((" %d", *it));
|
|---|
| 292 | LogDHCP((" }\n"));
|
|---|
| 293 | }
|
|---|
| 294 |
|
|---|
| 295 | bool fHeader = true;
|
|---|
| 296 | for (rawopts_t::const_iterator it = m_rawopts.begin();
|
|---|
| 297 | it != m_rawopts.end(); ++it)
|
|---|
| 298 | {
|
|---|
| 299 | const uint8_t optcode = (*it).first;
|
|---|
| 300 | switch (optcode) {
|
|---|
| 301 | case OptMessageType::optcode: /* FALLTHROUGH */
|
|---|
| 302 | case OptClientId::optcode: /* FALLTHROUGH */
|
|---|
| 303 | case OptRequestedAddress::optcode: /* FALLTHROUGH */
|
|---|
| 304 | case OptLeaseTime::optcode: /* FALLTHROUGH */
|
|---|
| 305 | case OptParameterRequest::optcode: /* FALLTHROUGH */
|
|---|
| 306 | case OptRapidCommit::optcode:
|
|---|
| 307 | break;
|
|---|
| 308 |
|
|---|
| 309 | default:
|
|---|
| 310 | if (fHeader)
|
|---|
| 311 | {
|
|---|
| 312 | LogDHCP((" other options:"));
|
|---|
| 313 | fHeader = false;
|
|---|
| 314 | }
|
|---|
| 315 | LogDHCP((" %d", optcode));
|
|---|
| 316 | break;
|
|---|
| 317 | }
|
|---|
| 318 | }
|
|---|
| 319 | if (!fHeader)
|
|---|
| 320 | LogDHCP(("\n"));
|
|---|
| 321 | }
|
|---|
| 322 |
|
|---|
| 323 |
|
|---|
| 324 | DhcpServerMessage::DhcpServerMessage(const DhcpClientMessage &req,
|
|---|
| 325 | uint8_t messageTypeParam, RTNETADDRIPV4 serverAddr)
|
|---|
| 326 | : DhcpMessage(),
|
|---|
| 327 | m_optServerId(serverAddr)
|
|---|
| 328 | {
|
|---|
| 329 | m_dst.u = 0xffffffff; /* broadcast */
|
|---|
| 330 |
|
|---|
| 331 | m_optMessageType = OptMessageType(messageTypeParam);
|
|---|
| 332 |
|
|---|
| 333 | /* copy values from the request (cf. RFC2131 Table 3) */
|
|---|
| 334 | m_xid = req.xid();
|
|---|
| 335 | m_flags = req.flags();
|
|---|
| 336 | m_giaddr = req.giaddr();
|
|---|
| 337 | m_mac = req.mac();
|
|---|
| 338 |
|
|---|
| 339 | if (req.messageType() == RTNET_DHCP_MT_REQUEST)
|
|---|
| 340 | m_ciaddr = req.ciaddr();
|
|---|
| 341 | }
|
|---|
| 342 |
|
|---|
| 343 |
|
|---|
| 344 | void DhcpServerMessage::maybeUnicast(const DhcpClientMessage &req)
|
|---|
| 345 | {
|
|---|
| 346 | if (!req.broadcast() && req.ciaddr().u != 0)
|
|---|
| 347 | setDst(req.ciaddr());
|
|---|
| 348 | }
|
|---|
| 349 |
|
|---|
| 350 |
|
|---|
| 351 | void DhcpServerMessage::addOption(DhcpOption *opt)
|
|---|
| 352 | {
|
|---|
| 353 | m_optmap << opt;
|
|---|
| 354 | }
|
|---|
| 355 |
|
|---|
| 356 |
|
|---|
| 357 | void DhcpServerMessage::addOptions(const optmap_t &optmap)
|
|---|
| 358 | {
|
|---|
| 359 | for (optmap_t::const_iterator it ( optmap.begin() );
|
|---|
| 360 | it != optmap.end(); ++it)
|
|---|
| 361 | {
|
|---|
| 362 | m_optmap << it->second;
|
|---|
| 363 | }
|
|---|
| 364 | }
|
|---|
| 365 |
|
|---|
| 366 |
|
|---|
| 367 | int DhcpServerMessage::encode(octets_t &data)
|
|---|
| 368 | {
|
|---|
| 369 | /*
|
|---|
| 370 | * Header, including DHCP cookie.
|
|---|
| 371 | */
|
|---|
| 372 | RTNETBOOTP bp;
|
|---|
| 373 | RT_ZERO(bp);
|
|---|
| 374 |
|
|---|
| 375 | bp.bp_op = RTNETBOOTP_OP_REPLY;
|
|---|
| 376 | bp.bp_htype = RTNET_ARP_ETHER;
|
|---|
| 377 | bp.bp_hlen = sizeof(RTMAC);
|
|---|
| 378 |
|
|---|
| 379 | bp.bp_xid = m_xid;
|
|---|
| 380 |
|
|---|
| 381 | bp.bp_ciaddr = m_ciaddr;
|
|---|
| 382 | bp.bp_yiaddr = m_yiaddr;
|
|---|
| 383 | bp.bp_siaddr = m_siaddr;
|
|---|
| 384 | bp.bp_giaddr = m_giaddr;
|
|---|
| 385 |
|
|---|
| 386 | bp.bp_chaddr.Mac = m_mac;
|
|---|
| 387 |
|
|---|
| 388 | bp.bp_vend.Dhcp.dhcp_cookie = RT_H2N_U32_C(RTNET_DHCP_COOKIE);
|
|---|
| 389 |
|
|---|
| 390 | data.insert(data.end(), (uint8_t *)&bp, (uint8_t *)&bp.bp_vend.Dhcp.dhcp_opts);
|
|---|
| 391 |
|
|---|
| 392 | /*
|
|---|
| 393 | * Options
|
|---|
| 394 | */
|
|---|
| 395 | data << m_optServerId
|
|---|
| 396 | << m_optMessageType;
|
|---|
| 397 |
|
|---|
| 398 | for (optmap_t::const_iterator it ( m_optmap.begin() );
|
|---|
| 399 | it != m_optmap.end(); ++it)
|
|---|
| 400 | {
|
|---|
| 401 | RTPrintf("encoding option %d\n", it->first);
|
|---|
| 402 | DhcpOption &opt = *it->second;
|
|---|
| 403 | data << opt;
|
|---|
| 404 | }
|
|---|
| 405 |
|
|---|
| 406 | data << OptEnd();
|
|---|
| 407 |
|
|---|
| 408 | if (data.size() < 548) /* XXX */
|
|---|
| 409 | data.resize(548);
|
|---|
| 410 |
|
|---|
| 411 | return VINF_SUCCESS;
|
|---|
| 412 | }
|
|---|
