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-rw-r--r--dhcp.c183
1 files changed, 0 insertions, 183 deletions
diff --git a/dhcp.c b/dhcp.c
deleted file mode 100644
index 3474a17..0000000
--- a/dhcp.c
+++ /dev/null
@@ -1,183 +0,0 @@
-/*
- * OpenVPN -- An application to securely tunnel IP networks
- * over a single TCP/UDP port, with support for SSL/TLS-based
- * session authentication and key exchange,
- * packet encryption, packet authentication, and
- * packet compression.
- *
- * Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation.
- *
- * 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 (see the file COPYING included with this
- * distribution); if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#include "syshead.h"
-
-#include "dhcp.h"
-#include "socket.h"
-#include "error.h"
-
-#include "memdbg.h"
-
-static int
-get_dhcp_message_type (const struct dhcp *dhcp, const int optlen)
-{
- const uint8_t *p = (uint8_t *) (dhcp + 1);
- int i;
-
- for (i = 0; i < optlen; ++i)
- {
- const uint8_t type = p[i];
- const int room = optlen - i;
- if (type == DHCP_END) /* didn't find what we were looking for */
- return -1;
- else if (type == DHCP_PAD) /* no-operation */
- ;
- else if (type == DHCP_MSG_TYPE) /* what we are looking for */
- {
- if (room >= 3)
- {
- if (p[i+1] == 1) /* option length should be 1 */
- return p[i+2]; /* return message type */
- }
- return -1;
- }
- else /* some other option */
- {
- if (room >= 2)
- {
- const int len = p[i+1]; /* get option length */
- i += (len + 1); /* advance to next option */
- }
- }
- }
- return -1;
-}
-
-static in_addr_t
-do_extract (struct dhcp *dhcp, const int optlen)
-{
- uint8_t *p = (uint8_t *) (dhcp + 1);
- int i;
- in_addr_t ret = 0;
-
- for (i = 0; i < optlen; ++i)
- {
- const uint8_t type = p[i];
- const int room = optlen - i;
- if (type == DHCP_END)
- break;
- else if (type == DHCP_PAD)
- ;
- else if (type == DHCP_ROUTER)
- {
- if (room >= 2)
- {
- const int len = p[i+1]; /* get option length */
- if (len <= (room-2))
- {
- if (!ret && len >= 4 && (len & 3) == 0)
- {
- memcpy (&ret, p+i+2, 4); /* get router IP address */
- ret = ntohl (ret);
- }
- memset (p+i, DHCP_PAD, len+2); /* delete the router option by padding it out */
- }
- i += (len + 1); /* advance to next option */
- }
- }
- else /* some other option */
- {
- if (room >= 2)
- {
- const int len = p[i+1]; /* get option length */
- i += (len + 1); /* advance to next option */
- }
- }
- }
- return ret;
-}
-
-static uint16_t
-udp_checksum (const uint8_t *buf,
- const int len_udp,
- const uint8_t *src_addr,
- const uint8_t *dest_addr)
-{
- uint16_t word16;
- uint32_t sum = 0;
- int i;
-
- /* make 16 bit words out of every two adjacent 8 bit words and */
- /* calculate the sum of all 16 bit words */
- for (i = 0; i < len_udp; i += 2){
- word16 = ((buf[i] << 8) & 0xFF00) + ((i + 1 < len_udp) ? (buf[i+1] & 0xFF) : 0);
- sum += word16;
- }
-
- /* add the UDP pseudo header which contains the IP source and destination addresses */
- for (i = 0; i < 4; i += 2){
- word16 =((src_addr[i] << 8) & 0xFF00) + (src_addr[i+1] & 0xFF);
- sum += word16;
- }
- for (i = 0; i < 4; i += 2){
- word16 =((dest_addr[i] << 8) & 0xFF00) + (dest_addr[i+1] & 0xFF);
- sum += word16;
- }
-
- /* the protocol number and the length of the UDP packet */
- sum += (uint16_t) OPENVPN_IPPROTO_UDP + (uint16_t) len_udp;
-
- /* keep only the last 16 bits of the 32 bit calculated sum and add the carries */
- while (sum >> 16)
- sum = (sum & 0xFFFF) + (sum >> 16);
-
- /* Take the one's complement of sum */
- return ((uint16_t) ~sum);
-}
-
-in_addr_t
-dhcp_extract_router_msg (struct buffer *ipbuf)
-{
- struct dhcp_full *df = (struct dhcp_full *) BPTR (ipbuf);
- const int optlen = BLEN (ipbuf) - (sizeof (struct openvpn_iphdr) + sizeof (struct openvpn_udphdr) + sizeof (struct dhcp));
-
- if (optlen >= 0
- && df->ip.protocol == OPENVPN_IPPROTO_UDP
- && df->udp.source == htons (BOOTPS_PORT)
- && df->udp.dest == htons (BOOTPC_PORT)
- && df->dhcp.op == BOOTREPLY
- && get_dhcp_message_type (&df->dhcp, optlen) == DHCPACK)
- {
- /* get the router IP address while padding out all DHCP router options */
- const in_addr_t ret = do_extract (&df->dhcp, optlen);
-
- /* recompute the UDP checksum */
- df->udp.check = htons (udp_checksum ((uint8_t *) &df->udp,
- sizeof (struct openvpn_udphdr) + sizeof (struct dhcp) + optlen,
- (uint8_t *)&df->ip.saddr,
- (uint8_t *)&df->ip.daddr));
-
- if (ret)
- {
- struct gc_arena gc = gc_new ();
- msg (D_ROUTE, "Extracted DHCP router address: %s", print_in_addr_t (ret, 0, &gc));
- gc_free (&gc);
- }
-
- return ret;
- }
- else
- return 0;
-}