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-rwxr-xr-xtap-win32/dhcp.c599
1 files changed, 0 insertions, 599 deletions
diff --git a/tap-win32/dhcp.c b/tap-win32/dhcp.c
deleted file mode 100755
index 3891d42..0000000
--- a/tap-win32/dhcp.c
+++ /dev/null
@@ -1,599 +0,0 @@
-/*
- * TAP-Win32/TAP-Win64 -- A kernel driver to provide virtual tap
- * device functionality on Windows.
- *
- * This code was inspired by the CIPE-Win32 driver by Damion K. Wilson.
- *
- * This source code is Copyright (C) 2002-2010 OpenVPN Technologies, Inc.,
- * and is released under the GPL version 2 (see below).
- *
- * 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
- */
-
-//=========================
-// Code to set DHCP options
-//=========================
-
-VOID
-SetDHCPOpt (DHCPMsg *m, void *data, unsigned int len)
-{
- if (!m->overflow)
- {
- if (m->optlen + len <= DHCP_OPTIONS_BUFFER_SIZE)
- {
- if (len)
- {
- NdisMoveMemory (m->msg.options + m->optlen, data, len);
- m->optlen += len;
- }
- }
- else
- {
- m->overflow = TRUE;
- }
- }
-}
-
-VOID
-SetDHCPOpt0 (DHCPMsg *msg, int type)
-{
- DHCPOPT0 opt;
- opt.type = (UCHAR) type;
- SetDHCPOpt (msg, &opt, sizeof (opt));
-}
-
-VOID
-SetDHCPOpt8 (DHCPMsg *msg, int type, ULONG data)
-{
- DHCPOPT8 opt;
- opt.type = (UCHAR) type;
- opt.len = sizeof (opt.data);
- opt.data = (UCHAR) data;
- SetDHCPOpt (msg, &opt, sizeof (opt));
-}
-
-VOID
-SetDHCPOpt32 (DHCPMsg *msg, int type, ULONG data)
-{
- DHCPOPT32 opt;
- opt.type = (UCHAR) type;
- opt.len = sizeof (opt.data);
- opt.data = data;
- SetDHCPOpt (msg, &opt, sizeof (opt));
-}
-
-//==============
-// Checksum code
-//==============
-
-USHORT
-ip_checksum (const UCHAR *buf, const int len_ip_header)
-{
- USHORT word16;
- ULONG sum = 0;
- int i;
-
- // make 16 bit words out of every two adjacent 8 bit words in the packet
- // and add them up
- for (i = 0; i < len_ip_header - 1; i += 2) {
- word16 = ((buf[i] << 8) & 0xFF00) + (buf[i+1] & 0xFF);
- sum += (ULONG) word16;
- }
-
- // take only 16 bits out of the 32 bit sum and add up the carries
- while (sum >> 16)
- sum = (sum & 0xFFFF) + (sum >> 16);
-
- // one's complement the result
- return ((USHORT) ~sum);
-}
-
-USHORT
-udp_checksum (const UCHAR *buf,
- const int len_udp,
- const UCHAR *src_addr,
- const UCHAR *dest_addr)
-{
- USHORT word16;
- ULONG 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 += (USHORT) IPPROTO_UDP + (USHORT) 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 ((USHORT) ~sum);
-}
-
-//================================
-// Set IP and UDP packet checksums
-//================================
-
-VOID
-SetChecksumDHCPMsg (DHCPMsg *m)
-{
- // Set IP checksum
- m->msg.pre.ip.check = htons (ip_checksum ((UCHAR *) &m->msg.pre.ip, sizeof (IPHDR)));
-
- // Set UDP Checksum
- m->msg.pre.udp.check = htons (udp_checksum ((UCHAR *) &m->msg.pre.udp,
- sizeof (UDPHDR) + sizeof (DHCP) + m->optlen,
- (UCHAR *)&m->msg.pre.ip.saddr,
- (UCHAR *)&m->msg.pre.ip.daddr));
-}
-
-//===================
-// DHCP message tests
-//===================
-
-int
-GetDHCPMessageType (const DHCP *dhcp, const int optlen)
-{
- const UCHAR *p = (UCHAR *) (dhcp + 1);
- int i;
-
- for (i = 0; i < optlen; ++i)
- {
- const UCHAR type = p[i];
- const int room = optlen - i - 1;
- 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 >= 2)
- {
- if (p[i+1] == 1) // message length should be 1
- return p[i+2]; // return message type
- }
- return -1;
- }
- else // some other message
- {
- if (room >= 1)
- {
- const int len = p[i+1]; // get message length
- i += (len + 1); // advance to next message
- }
- }
- }
- return -1;
-}
-
-BOOLEAN
-DHCPMessageOurs (const TapAdapterPointer p_Adapter,
- const ETH_HEADER *eth,
- const IPHDR *ip,
- const UDPHDR *udp,
- const DHCP *dhcp)
-{
- // Must be UDPv4 protocol
- if (!(eth->proto == htons (ETH_P_IP) && ip->protocol == IPPROTO_UDP))
- return FALSE;
-
- // Source MAC must be our adapter
- if (!MAC_EQUAL (eth->src, p_Adapter->m_MAC))
- return FALSE;
-
- // Dest MAC must be either broadcast or our virtual DHCP server
- if (!(MAC_EQUAL (eth->dest, p_Adapter->m_MAC_Broadcast)
- || MAC_EQUAL (eth->dest, p_Adapter->m_dhcp_server_mac)))
- return FALSE;
-
- // Port numbers must be correct
- if (!(udp->dest == htons (BOOTPS_PORT)
- && udp->source == htons (BOOTPC_PORT)))
- return FALSE;
-
- // Hardware address must be MAC addr sized
- if (!(dhcp->hlen == sizeof (MACADDR)))
- return FALSE;
-
- // Hardware address must match our adapter
- if (!MAC_EQUAL (eth->src, dhcp->chaddr))
- return FALSE;
-
- return TRUE;
-}
-
-
-//=====================================================
-// Build all of DHCP packet except for DHCP options.
-// Assume that *p has been zeroed before we are called.
-//=====================================================
-
-VOID
-BuildDHCPPre (const TapAdapterPointer a,
- DHCPPre *p,
- const ETH_HEADER *eth,
- const IPHDR *ip,
- const UDPHDR *udp,
- const DHCP *dhcp,
- const int optlen,
- const int type)
-{
- // Should we broadcast or direct to a specific MAC / IP address?
- const BOOLEAN broadcast = (type == DHCPNAK
- || MAC_EQUAL (eth->dest, a->m_MAC_Broadcast));
- // Build ethernet header
-
- COPY_MAC (p->eth.src, a->m_dhcp_server_mac);
-
- if (broadcast)
- COPY_MAC (p->eth.dest, a->m_MAC_Broadcast);
- else
- COPY_MAC (p->eth.dest, eth->src);
-
- p->eth.proto = htons (ETH_P_IP);
-
- // Build IP header
-
- p->ip.version_len = (4 << 4) | (sizeof (IPHDR) >> 2);
- p->ip.tos = 0;
- p->ip.tot_len = htons (sizeof (IPHDR) + sizeof (UDPHDR) + sizeof (DHCP) + optlen);
- p->ip.id = 0;
- p->ip.frag_off = 0;
- p->ip.ttl = 16;
- p->ip.protocol = IPPROTO_UDP;
- p->ip.check = 0;
- p->ip.saddr = a->m_dhcp_server_ip;
-
- if (broadcast)
- p->ip.daddr = ~0;
- else
- p->ip.daddr = a->m_dhcp_addr;
-
- // Build UDP header
-
- p->udp.source = htons (BOOTPS_PORT);
- p->udp.dest = htons (BOOTPC_PORT);
- p->udp.len = htons (sizeof (UDPHDR) + sizeof (DHCP) + optlen);
- p->udp.check = 0;
-
- // Build DHCP response
-
- p->dhcp.op = BOOTREPLY;
- p->dhcp.htype = 1;
- p->dhcp.hlen = sizeof (MACADDR);
- p->dhcp.hops = 0;
- p->dhcp.xid = dhcp->xid;
- p->dhcp.secs = 0;
- p->dhcp.flags = 0;
- p->dhcp.ciaddr = 0;
-
- if (type == DHCPNAK)
- p->dhcp.yiaddr = 0;
- else
- p->dhcp.yiaddr = a->m_dhcp_addr;
-
- p->dhcp.siaddr = a->m_dhcp_server_ip;
- p->dhcp.giaddr = 0;
- COPY_MAC (p->dhcp.chaddr, eth->src);
- p->dhcp.magic = htonl (0x63825363);
-}
-//=============================
-// Build specific DHCP messages
-//=============================
-
-VOID
-SendDHCPMsg (const TapAdapterPointer a,
- const int type,
- const ETH_HEADER *eth,
- const IPHDR *ip,
- const UDPHDR *udp,
- const DHCP *dhcp)
-{
- DHCPMsg *pkt;
-
- if (!(type == DHCPOFFER || type == DHCPACK || type == DHCPNAK))
- {
- DEBUGP (("[TAP] SendDHCPMsg: Bad DHCP type: %d\n", type));
- return;
- }
-
- pkt = (DHCPMsg *) MemAlloc (sizeof (DHCPMsg), TRUE);
-
- if (pkt)
- {
- //-----------------------
- // Build DHCP options
- //-----------------------
-
- // Message Type
- SetDHCPOpt8 (pkt, DHCP_MSG_TYPE, type);
-
- // Server ID
- SetDHCPOpt32 (pkt, DHCP_SERVER_ID, a->m_dhcp_server_ip);
-
- if (type == DHCPOFFER || type == DHCPACK)
- {
- // Lease Time
- SetDHCPOpt32 (pkt, DHCP_LEASE_TIME, htonl (a->m_dhcp_lease_time));
-
- // Netmask
- SetDHCPOpt32 (pkt, DHCP_NETMASK, a->m_dhcp_netmask);
-
- // Other user-defined options
- SetDHCPOpt (pkt,
- a->m_dhcp_user_supplied_options_buffer,
- a->m_dhcp_user_supplied_options_buffer_len);
- }
-
- // End
- SetDHCPOpt0 (pkt, DHCP_END);
-
- if (!DHCPMSG_OVERFLOW (pkt))
- {
- // The initial part of the DHCP message (not including options) gets built here
- BuildDHCPPre (a,
- &pkt->msg.pre,
- eth,
- ip,
- udp,
- dhcp,
- DHCPMSG_LEN_OPT (pkt),
- type);
-
- SetChecksumDHCPMsg (pkt);
-
- DUMP_PACKET ("DHCPMsg",
- DHCPMSG_BUF (pkt),
- DHCPMSG_LEN_FULL (pkt));
-
- // Return DHCP response to kernel
- InjectPacketDeferred (a,
- DHCPMSG_BUF (pkt),
- DHCPMSG_LEN_FULL (pkt));
- }
- else
- {
- DEBUGP (("[TAP] SendDHCPMsg: DHCP buffer overflow\n"));
- }
-
- MemFree (pkt, sizeof (DHCPMsg));
- }
-}
-
-//===================================================================
-// Handle a BOOTPS packet produced by the local system to
-// resolve the address/netmask of this adapter.
-// If we are in TAP_IOCTL_CONFIG_DHCP_MASQ mode, reply
-// to the message. Return TRUE if we processed the passed
-// message, so that downstream stages can ignore it.
-//===================================================================
-
-BOOLEAN
-ProcessDHCP (TapAdapterPointer p_Adapter,
- const ETH_HEADER *eth,
- const IPHDR *ip,
- const UDPHDR *udp,
- const DHCP *dhcp,
- int optlen)
-{
- int msg_type;
-
- // Sanity check IP header
- if (!(ntohs (ip->tot_len) == sizeof (IPHDR) + sizeof (UDPHDR) + sizeof (DHCP) + optlen
- && (ntohs (ip->frag_off) & IP_OFFMASK) == 0))
- return TRUE;
-
- // Does this message belong to us?
- if (!DHCPMessageOurs (p_Adapter, eth, ip, udp, dhcp))
- return FALSE;
-
- msg_type = GetDHCPMessageType (dhcp, optlen);
-
- // Drop non-BOOTREQUEST messages
- if (dhcp->op != BOOTREQUEST)
- return TRUE;
-
- // Drop any messages except DHCPDISCOVER or DHCPREQUEST
- if (!(msg_type == DHCPDISCOVER || msg_type == DHCPREQUEST))
- return TRUE;
-
- // Should we reply with DHCPOFFER, DHCPACK, or DHCPNAK?
- if (msg_type == DHCPREQUEST
- && ((dhcp->ciaddr && dhcp->ciaddr != p_Adapter->m_dhcp_addr)
- || !p_Adapter->m_dhcp_received_discover
- || p_Adapter->m_dhcp_bad_requests >= BAD_DHCPREQUEST_NAK_THRESHOLD))
- SendDHCPMsg (p_Adapter,
- DHCPNAK,
- eth, ip, udp, dhcp);
- else
- SendDHCPMsg (p_Adapter,
- (msg_type == DHCPDISCOVER ? DHCPOFFER : DHCPACK),
- eth, ip, udp, dhcp);
-
- // Remember if we received a DHCPDISCOVER
- if (msg_type == DHCPDISCOVER)
- p_Adapter->m_dhcp_received_discover = TRUE;
-
- // Is this a bad DHCPREQUEST?
- if (msg_type == DHCPREQUEST && dhcp->ciaddr != p_Adapter->m_dhcp_addr)
- ++p_Adapter->m_dhcp_bad_requests;
-
- return TRUE;
-}
-
-#if DBG
-
-const char *
-message_op_text (int op)
-{
- switch (op)
- {
- case BOOTREQUEST:
- return "BOOTREQUEST";
- case BOOTREPLY:
- return "BOOTREPLY";
- default:
- return "???";
- }
-}
-
-const char *
-message_type_text (int type)
-{
- switch (type)
- {
- case DHCPDISCOVER:
- return "DHCPDISCOVER";
- case DHCPOFFER:
- return "DHCPOFFER";
- case DHCPREQUEST:
- return "DHCPREQUEST";
- case DHCPDECLINE:
- return "DHCPDECLINE";
- case DHCPACK:
- return "DHCPACK";
- case DHCPNAK:
- return "DHCPNAK";
- case DHCPRELEASE:
- return "DHCPRELEASE";
- case DHCPINFORM:
- return "DHCPINFORM";
- default:
- return "???";
- }
-}
-
-const char *
-port_name (int port)
-{
- switch (port)
- {
- case BOOTPS_PORT:
- return "BOOTPS";
- case BOOTPC_PORT:
- return "BOOTPC";
- default:
- return "unknown";
- }
-}
-
-VOID
-DumpDHCP (const ETH_HEADER *eth,
- const IPHDR *ip,
- const UDPHDR *udp,
- const DHCP *dhcp,
- const int optlen)
-{
- DEBUGP ((" %s", message_op_text (dhcp->op)));
- DEBUGP ((" %s ", message_type_text (GetDHCPMessageType (dhcp, optlen))));
- PrIP (ip->saddr);
- DEBUGP ((":%s[", port_name (ntohs (udp->source))));
- PrMac (eth->src);
- DEBUGP (("] -> "));
- PrIP (ip->daddr);
- DEBUGP ((":%s[", port_name (ntohs (udp->dest))));
- PrMac (eth->dest);
- DEBUGP (("]"));
- if (dhcp->ciaddr)
- {
- DEBUGP ((" ci="));
- PrIP (dhcp->ciaddr);
- }
- if (dhcp->yiaddr)
- {
- DEBUGP ((" yi="));
- PrIP (dhcp->yiaddr);
- }
- if (dhcp->siaddr)
- {
- DEBUGP ((" si="));
- PrIP (dhcp->siaddr);
- }
- if (dhcp->hlen == sizeof (MACADDR))
- {
- DEBUGP ((" ch="));
- PrMac (dhcp->chaddr);
- }
-
- DEBUGP ((" xid=0x%08x", ntohl (dhcp->xid)));
-
- if (ntohl (dhcp->magic) != 0x63825363)
- DEBUGP ((" ma=0x%08x", ntohl (dhcp->magic)));
- if (dhcp->htype != 1)
- DEBUGP ((" htype=%d", dhcp->htype));
- if (dhcp->hops)
- DEBUGP ((" hops=%d", dhcp->hops));
- if (ntohs (dhcp->secs))
- DEBUGP ((" secs=%d", ntohs (dhcp->secs)));
- if (ntohs (dhcp->flags))
- DEBUGP ((" flags=0x%04x", ntohs (dhcp->flags)));
-
- // extra stuff
-
- if (ip->version_len != 0x45)
- DEBUGP ((" vl=0x%02x", ip->version_len));
- if (ntohs (ip->tot_len) != sizeof (IPHDR) + sizeof (UDPHDR) + sizeof (DHCP) + optlen)
- DEBUGP ((" tl=%d", ntohs (ip->tot_len)));
- if (ntohs (udp->len) != sizeof (UDPHDR) + sizeof (DHCP) + optlen)
- DEBUGP ((" ul=%d", ntohs (udp->len)));
-
- if (ip->tos)
- DEBUGP ((" tos=0x%02x", ip->tos));
- if (ntohs (ip->id))
- DEBUGP ((" id=0x%04x", ntohs (ip->id)));
- if (ntohs (ip->frag_off))
- DEBUGP ((" frag_off=0x%04x", ntohs (ip->frag_off)));
-
- DEBUGP ((" ttl=%d", ip->ttl));
- DEBUGP ((" ic=0x%04x [0x%04x]", ntohs (ip->check),
- ip_checksum ((UCHAR*)ip, sizeof (IPHDR))));
- DEBUGP ((" uc=0x%04x [0x%04x/%d]", ntohs (udp->check),
- udp_checksum ((UCHAR *) udp,
- sizeof (UDPHDR) + sizeof (DHCP) + optlen,
- (UCHAR *) &ip->saddr,
- (UCHAR *) &ip->daddr),
- optlen));
-
- // Options
- {
- const UCHAR *opt = (UCHAR *) (dhcp + 1);
- int i;
-
- DEBUGP ((" OPT"));
- for (i = 0; i < optlen; ++i)
- {
- const UCHAR data = opt[i];
- DEBUGP ((".%d", data));
- }
- }
-}
-
-#endif /* DBG */
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