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Diffstat (limited to 'src/VBox/NetworkServices/NAT/proxy_dhcp6ds.c')
-rw-r--r--src/VBox/NetworkServices/NAT/proxy_dhcp6ds.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/src/VBox/NetworkServices/NAT/proxy_dhcp6ds.c b/src/VBox/NetworkServices/NAT/proxy_dhcp6ds.c
new file mode 100644
index 00000000..a42629f7
--- /dev/null
+++ b/src/VBox/NetworkServices/NAT/proxy_dhcp6ds.c
@@ -0,0 +1,327 @@
+/* $Id: proxy_dhcp6ds.c $ */
+/** @file
+ * NAT Network - Simple stateless DHCPv6 (RFC 3736) server.
+ */
+
+/*
+ * Copyright (C) 2013-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#define LOG_GROUP LOG_GROUP_NAT_SERVICE
+
+#include "winutils.h"
+#include "dhcp6.h"
+#include "proxy.h"
+
+#include <string.h>
+
+#include "lwip/opt.h"
+#include "lwip/mld6.h"
+#include "lwip/udp.h"
+
+
+static void dhcp6ds_recv(void *, struct udp_pcb *, struct pbuf *, ip6_addr_t *, u16_t);
+
+
+/* ff02::1:2 - "All_DHCP_Relay_Agents_and_Servers" link-scoped multicast */
+static /* const */ ip6_addr_t all_dhcp_relays_and_servers = {
+ { PP_HTONL(0xff020000UL), 0, 0, PP_HTONL(0x00010002UL) }
+};
+
+/* ff05::1:3 - "All_DHCP_Servers" site-scoped multicast */
+static /* const */ ip6_addr_t all_dhcp_servers = {
+ { PP_HTONL(0xff050000UL), 0, 0, PP_HTONL(0x00010003UL) }
+};
+
+
+static struct udp_pcb *dhcp6ds_pcb;
+
+/* prebuilt Server ID option */
+#define DUID_LL_LEN (/* duid type */ 2 + /* hw type */ 2 + /* ether addr */ 6)
+static u8_t dhcp6ds_serverid[/* opt */ 2 + /* optlen */ 2 + DUID_LL_LEN];
+
+/* prebuilt DNS Servers option */
+static u8_t dhcp6ds_dns[/* opt */ 2 + /* optlen */ 2 + /* IPv6 addr */ 16];
+
+
+/**
+ * Initialize DHCP6 server.
+ *
+ * Join DHCP6 multicast groups.
+ * Create and bind server pcb.
+ * Prebuild fixed parts of reply.
+ */
+err_t
+dhcp6ds_init(struct netif *proxy_netif)
+{
+ ip6_addr_t *pxaddr, *pxaddr_nonlocal;
+ int i;
+ err_t error;
+
+ LWIP_ASSERT1(proxy_netif != NULL);
+ LWIP_ASSERT1(proxy_netif->hwaddr_len == 6); /* ethernet */
+
+ pxaddr = netif_ip6_addr(proxy_netif, 0); /* link local */
+
+ /*
+ * XXX: TODO: This is a leftover from testing with IPv6 mapped
+ * loopback with a special IPv6->IPv4 mapping hack in pxudp.c
+ */
+ /* advertise ourself as DNS resolver - will be proxied to host */
+ pxaddr_nonlocal = NULL;
+ for (i = 1; i < LWIP_IPV6_NUM_ADDRESSES; ++i) {
+ if (ip6_addr_ispreferred(netif_ip6_addr_state(proxy_netif, i))
+ && !ip6_addr_islinklocal(netif_ip6_addr(proxy_netif, i)))
+ {
+ pxaddr_nonlocal = netif_ip6_addr(proxy_netif, i);
+ break;
+ }
+ }
+ LWIP_ASSERT1(pxaddr_nonlocal != NULL); /* must be configured on the netif */
+
+
+ error = mld6_joingroup(pxaddr, &all_dhcp_relays_and_servers);
+ if (error != ERR_OK) {
+ DPRINTF0(("%s: failed to join All_DHCP_Relay_Agents_and_Servers: %s\n",
+ __func__, proxy_lwip_strerr(error)));
+ goto err;
+ }
+
+ error = mld6_joingroup(pxaddr, &all_dhcp_servers);
+ if (error != ERR_OK) {
+ DPRINTF0(("%s: failed to join All_DHCP_Servers: %s\n",
+ __func__, proxy_lwip_strerr(error)));
+ goto err1;
+ }
+
+
+ dhcp6ds_pcb = udp_new_ip6();
+ if (dhcp6ds_pcb == NULL) {
+ DPRINTF0(("%s: failed to allocate PCB\n", __func__));
+ error = ERR_MEM;
+ goto err2;
+ }
+
+ udp_recv_ip6(dhcp6ds_pcb, dhcp6ds_recv, NULL);
+
+ error = udp_bind_ip6(dhcp6ds_pcb, pxaddr, DHCP6_SERVER_PORT);
+ if (error != ERR_OK) {
+ DPRINTF0(("%s: failed to bind PCB\n", __func__));
+ goto err3;
+ }
+
+
+#define OPT_SET(buf, off, c) do { \
+ u16_t _s = PP_HTONS(c); \
+ memcpy(&(buf)[off], &_s, sizeof(u16_t)); \
+ } while (0)
+
+#define SERVERID_SET(off, c) OPT_SET(dhcp6ds_serverid, (off), (c))
+#define DNSSRV_SET(off, c) OPT_SET(dhcp6ds_dns, (off), (c))
+
+ SERVERID_SET(0, DHCP6_OPTION_SERVERID);
+ SERVERID_SET(2, DUID_LL_LEN);
+ SERVERID_SET(4, DHCP6_DUID_LL);
+ SERVERID_SET(6, ARES_HRD_ETHERNET);
+ memcpy(&dhcp6ds_serverid[8], proxy_netif->hwaddr, 6);
+
+ DNSSRV_SET(0, DHCP6_OPTION_DNS_SERVERS);
+ DNSSRV_SET(2, 16); /* one IPv6 address */
+ /*
+ * XXX: TODO: This is a leftover from testing with IPv6 mapped
+ * loopback with a special IPv6->IPv4 mapping hack in pxudp.c
+ */
+ memcpy(&dhcp6ds_dns[4], pxaddr_nonlocal, sizeof(ip6_addr_t));
+
+#undef SERVERID_SET
+#undef DNSSRV_SET
+
+ return ERR_OK;
+
+
+ err3:
+ udp_remove(dhcp6ds_pcb);
+ dhcp6ds_pcb = NULL;
+ err2:
+ mld6_leavegroup(pxaddr, &all_dhcp_servers);
+ err1:
+ mld6_leavegroup(pxaddr, &all_dhcp_relays_and_servers);
+ err:
+ return error;
+}
+
+
+static u8_t dhcp6ds_reply_buf[1024];
+
+static void
+dhcp6ds_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p,
+ ip6_addr_t *addr, u16_t port)
+{
+ u8_t msg_header[4];
+ unsigned int msg_type, msg_tid;
+ int copied;
+ size_t roff;
+ struct pbuf *q;
+ err_t error;
+
+ LWIP_UNUSED_ARG(arg);
+ LWIP_ASSERT1(p != NULL);
+
+ copied = pbuf_copy_partial(p, msg_header, sizeof(msg_header), 0);
+ if (copied != sizeof(msg_header)) {
+ DPRINTF(("%s: message header truncated\n", __func__));
+ pbuf_free(p);
+ return;
+ }
+ pbuf_header(p, -(s16_t)sizeof(msg_header));
+
+ msg_type = msg_header[0];
+ msg_tid = (msg_header[1] << 16) | (msg_header[2] << 8) | msg_header[3];
+ DPRINTF(("%s: type %u, tid 0x%6x\n", __func__, msg_type, msg_tid));
+ if (msg_type != DHCP6_INFORMATION_REQUEST) { /** @todo ? RELAY_FORW */
+ pbuf_free(p);
+ return;
+ }
+
+ roff = 0;
+
+ msg_header[0] = DHCP6_REPLY;
+ memcpy(dhcp6ds_reply_buf + roff, msg_header, sizeof(msg_header));
+ roff += sizeof(msg_header);
+
+
+ /* loop over options */
+ while (p->tot_len > 0) {
+ u16_t opt, optlen;
+
+ /* fetch option code */
+ copied = pbuf_copy_partial(p, &opt, sizeof(opt), 0);
+ if (copied != sizeof(opt)) {
+ DPRINTF(("%s: option header truncated\n", __func__));
+ pbuf_free(p);
+ return;
+ }
+ pbuf_header(p, -(s16_t)sizeof(opt));
+ opt = ntohs(opt);
+
+ /* fetch option length */
+ copied = pbuf_copy_partial(p, &optlen, sizeof(optlen), 0);
+ if (copied != sizeof(optlen)) {
+ DPRINTF(("%s: option %u length truncated\n", __func__, opt));
+ pbuf_free(p);
+ return;
+ }
+ pbuf_header(p, -(s16_t)sizeof(optlen));
+ optlen = ntohs(optlen);
+
+ /* enough data? */
+ if (optlen > p->tot_len) {
+ DPRINTF(("%s: option %u truncated: expect %u, got %u\n",
+ __func__, opt, optlen, p->tot_len));
+ pbuf_free(p);
+ return;
+ }
+
+ DPRINTF2(("%s: option %u length %u\n", __func__, opt, optlen));
+
+ if (opt == DHCP6_OPTION_CLIENTID) {
+ u16_t s;
+
+ /* "A DUID can be no more than 128 octets long (not
+ including the type code)." */
+ if (optlen > 130) {
+ DPRINTF(("%s: client DUID too long: %u\n", __func__, optlen));
+ pbuf_free(p);
+ return;
+ }
+
+ s = PP_HTONS(DHCP6_OPTION_CLIENTID);
+ memcpy(dhcp6ds_reply_buf + roff, &s, sizeof(s));
+ roff += sizeof(s);
+
+ s = ntohs(optlen);
+ memcpy(dhcp6ds_reply_buf + roff, &s, sizeof(s));
+ roff += sizeof(s);
+
+ pbuf_copy_partial(p, dhcp6ds_reply_buf + roff, optlen, 0);
+ roff += optlen;
+ }
+ else if (opt == DHCP6_OPTION_ORO) {
+ u16_t *opts;
+ int i, nopts;
+
+ if (optlen % 2 != 0) {
+ DPRINTF2(("%s: Option Request of odd length\n", __func__));
+ goto bad_oro;
+ }
+ nopts = optlen / 2;
+
+ opts = (u16_t *)malloc(optlen);
+ if (opts == NULL) {
+ DPRINTF2(("%s: failed to allocate space for Option Request\n",
+ __func__));
+ goto bad_oro;
+ }
+
+ pbuf_copy_partial(p, opts, optlen, 0);
+ for (i = 0; i < nopts; ++i) {
+ opt = ntohs(opts[i]);
+ DPRINTF2(("> request option %u\n", opt));
+ };
+ free(opts);
+
+ bad_oro: /* empty */;
+ }
+
+ pbuf_header(p, -optlen); /* go to next option */
+ }
+ pbuf_free(p); /* done */
+
+
+ memcpy(dhcp6ds_reply_buf + roff, dhcp6ds_serverid, sizeof(dhcp6ds_serverid));
+ roff += sizeof(dhcp6ds_serverid);
+
+ memcpy(dhcp6ds_reply_buf + roff, dhcp6ds_dns, sizeof(dhcp6ds_dns));
+ roff += sizeof(dhcp6ds_dns);
+
+ Assert(roff == (u16_t)roff);
+ q = pbuf_alloc(PBUF_RAW, (u16_t)roff, PBUF_RAM);
+ if (q == NULL) {
+ DPRINTF(("%s: pbuf_alloc(%d) failed\n", __func__, (int)roff));
+ return;
+ }
+
+ error = pbuf_take(q, dhcp6ds_reply_buf, (u16_t)roff);
+ if (error != ERR_OK) {
+ DPRINTF(("%s: pbuf_take(%d) failed: %s\n",
+ __func__, (int)roff, proxy_lwip_strerr(error)));
+ pbuf_free(q);
+ return;
+ }
+
+ error = udp_sendto_ip6(pcb, q, addr, port);
+ if (error != ERR_OK) {
+ DPRINTF(("%s: udp_sendto failed: %s\n",
+ __func__, proxy_lwip_strerr(error)));
+ }
+
+ pbuf_free(q);
+}
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