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alias.c (59726) alias.c (61861)
1/* -*- mode: c; tab-width: 8; c-basic-indent: 4; -*- */
2/*
3 Alias.c provides supervisory control for the functions of the
4 packet aliasing software. It consists of routines to monitor
5 TCP connection state, protocol-specific aliasing routines,
6 fragment handling and the following outside world functional
7 interfaces: SaveFragmentPtr, GetFragmentPtr, FragmentAliasIn,
8 PacketAliasIn and PacketAliasOut.

--- 62 unchanged lines hidden (view full) ---

71 - Rationalized API function names to begin
72 with "PacketAlias..."
73 - Eliminated PacketAliasIn2() and
74 PacketAliasOut2() as poorly conceived.
75
76 Version 2.3 Dec 1998 (dillon)
77 - Major bounds checking additions, see FreeBSD/CVS
78
1/* -*- mode: c; tab-width: 8; c-basic-indent: 4; -*- */
2/*
3 Alias.c provides supervisory control for the functions of the
4 packet aliasing software. It consists of routines to monitor
5 TCP connection state, protocol-specific aliasing routines,
6 fragment handling and the following outside world functional
7 interfaces: SaveFragmentPtr, GetFragmentPtr, FragmentAliasIn,
8 PacketAliasIn and PacketAliasOut.

--- 62 unchanged lines hidden (view full) ---

71 - Rationalized API function names to begin
72 with "PacketAlias..."
73 - Eliminated PacketAliasIn2() and
74 PacketAliasOut2() as poorly conceived.
75
76 Version 2.3 Dec 1998 (dillon)
77 - Major bounds checking additions, see FreeBSD/CVS
78
79 Version 3.1 May, 2000 (eds)
80 - Added hooks to handle PPTP.
81
79 See HISTORY file for additional revisions.
80
82 See HISTORY file for additional revisions.
83
81 $FreeBSD: head/sys/netinet/libalias/alias.c 59726 2000-04-28 13:44:49Z ru $
84 $FreeBSD: head/sys/netinet/libalias/alias.c 61861 2000-06-20 11:41:48Z ru $
82*/
83
84#include <sys/types.h>
85
86#include <netinet/in_systm.h>
87#include <netinet/in.h>
88#include <netinet/ip.h>
89#include <netinet/ip_icmp.h>
90#include <netinet/tcp.h>
91#include <netinet/udp.h>
92
85*/
86
87#include <sys/types.h>
88
89#include <netinet/in_systm.h>
90#include <netinet/in.h>
91#include <netinet/ip.h>
92#include <netinet/ip_icmp.h>
93#include <netinet/tcp.h>
94#include <netinet/udp.h>
95
93#ifndef IPPROTO_GRE
94#define IPPROTO_GRE 47
95#define IPPROTO_ESP 50
96#define IPPROTO_AH 51
97#endif
98
99#include "alias_local.h"
100#include "alias.h"
101
102#define NETBIOS_NS_PORT_NUMBER 137
103#define NETBIOS_DGM_PORT_NUMBER 138
104#define FTP_CONTROL_PORT_NUMBER 21
105#define IRC_CONTROL_PORT_NUMBER_1 6667
106#define IRC_CONTROL_PORT_NUMBER_2 6668
107#define CUSEEME_PORT_NUMBER 7648
96#include "alias_local.h"
97#include "alias.h"
98
99#define NETBIOS_NS_PORT_NUMBER 137
100#define NETBIOS_DGM_PORT_NUMBER 138
101#define FTP_CONTROL_PORT_NUMBER 21
102#define IRC_CONTROL_PORT_NUMBER_1 6667
103#define IRC_CONTROL_PORT_NUMBER_2 6668
104#define CUSEEME_PORT_NUMBER 7648
105#define PPTP_CONTROL_PORT_NUMBER 1723
108
109
110
111
112/* TCP Handling Routines
113
114 TcpMonitorIn() -- These routines monitor TCP connections, and
115 TcpMonitorOut() delete a link when a connection is closed.

--- 60 unchanged lines hidden (view full) ---

176
177/* Protocol Specific Packet Aliasing Routines
178
179 IcmpAliasIn(), IcmpAliasIn1(), IcmpAliasIn2(), IcmpAliasIn3()
180 IcmpAliasOut(), IcmpAliasOut1(), IcmpAliasOut2(), IcmpAliasOut3()
181 ProtoAliasIn(), ProtoAliasOut()
182 UdpAliasIn(), UdpAliasOut()
183 TcpAliasIn(), TcpAliasOut()
106
107
108
109
110/* TCP Handling Routines
111
112 TcpMonitorIn() -- These routines monitor TCP connections, and
113 TcpMonitorOut() delete a link when a connection is closed.

--- 60 unchanged lines hidden (view full) ---

174
175/* Protocol Specific Packet Aliasing Routines
176
177 IcmpAliasIn(), IcmpAliasIn1(), IcmpAliasIn2(), IcmpAliasIn3()
178 IcmpAliasOut(), IcmpAliasOut1(), IcmpAliasOut2(), IcmpAliasOut3()
179 ProtoAliasIn(), ProtoAliasOut()
180 UdpAliasIn(), UdpAliasOut()
181 TcpAliasIn(), TcpAliasOut()
182 GreAliasIn()
184
185These routines handle protocol specific details of packet aliasing.
186One may observe a certain amount of repetitive arithmetic in these
187functions, the purpose of which is to compute a revised checksum
188without actually summing over the entire data packet, which could be
189unnecessarily time consuming.
190
191The purpose of the packet aliasing routines is to replace the source

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229static int ProtoAliasOut(struct ip *);
230
231static int UdpAliasOut(struct ip *);
232static int UdpAliasIn (struct ip *);
233
234static int TcpAliasOut(struct ip *, int);
235static int TcpAliasIn (struct ip *);
236
183
184These routines handle protocol specific details of packet aliasing.
185One may observe a certain amount of repetitive arithmetic in these
186functions, the purpose of which is to compute a revised checksum
187without actually summing over the entire data packet, which could be
188unnecessarily time consuming.
189
190The purpose of the packet aliasing routines is to replace the source

--- 37 unchanged lines hidden (view full) ---

228static int ProtoAliasOut(struct ip *);
229
230static int UdpAliasOut(struct ip *);
231static int UdpAliasIn (struct ip *);
232
233static int TcpAliasOut(struct ip *, int);
234static int TcpAliasIn (struct ip *);
235
236static int GreAliasIn(struct ip *);
237
237
238
238static int
239IcmpAliasIn1(struct ip *pip)
240{
241/*
242 De-alias incoming echo and timestamp replies
243*/
244 struct alias_link *link;
245 struct icmp *ic;

--- 474 unchanged lines hidden (view full) ---

720 pip->ip_src = alias_address;
721
722 return(PKT_ALIAS_OK);
723 }
724 return(PKT_ALIAS_IGNORED);
725}
726
727
239static int
240IcmpAliasIn1(struct ip *pip)
241{
242/*
243 De-alias incoming echo and timestamp replies
244*/
245 struct alias_link *link;
246 struct icmp *ic;

--- 474 unchanged lines hidden (view full) ---

721 pip->ip_src = alias_address;
722
723 return(PKT_ALIAS_OK);
724 }
725 return(PKT_ALIAS_IGNORED);
726}
727
728
729static int
730GreAliasIn(struct ip *pip)
731{
732 u_short call_id;
733 struct alias_link *link;
728
734
735/* Return if proxy-only mode is enabled. */
736 if (packetAliasMode & PKT_ALIAS_PROXY_ONLY)
737 return (PKT_ALIAS_OK);
738
739 if (PptpGetCallID(pip, &call_id)) {
740 if ((link = FindPptpIn(pip->ip_src, pip->ip_dst, call_id)) != NULL) {
741 struct in_addr alias_address;
742 struct in_addr original_address;
743
744 alias_address = GetAliasAddress(link);
745 original_address = GetOriginalAddress(link);
746 PptpSetCallID(pip, GetOriginalPort(link));
747
748 /* Restore original IP address. */
749 DifferentialChecksum(&pip->ip_sum,
750 (u_short *)&original_address,
751 (u_short *)&pip->ip_dst,
752 2);
753 pip->ip_dst = original_address;
754
755 return (PKT_ALIAS_OK);
756 } else
757 return (PKT_ALIAS_IGNORED);
758 } else
759 return ProtoAliasIn(pip);
760}
761
762
729static int
730UdpAliasIn(struct ip *pip)
731{
732 struct udphdr *ud;
733 struct alias_link *link;
734
735/* Return if proxy-only mode is enabled */
736 if (packetAliasMode & PKT_ALIAS_PROXY_ONLY)

--- 161 unchanged lines hidden (view full) ---

898 struct in_addr alias_address;
899 struct in_addr original_address;
900 struct in_addr proxy_address;
901 u_short alias_port;
902 u_short proxy_port;
903 int accumulate;
904 u_short *sptr;
905
763static int
764UdpAliasIn(struct ip *pip)
765{
766 struct udphdr *ud;
767 struct alias_link *link;
768
769/* Return if proxy-only mode is enabled */
770 if (packetAliasMode & PKT_ALIAS_PROXY_ONLY)

--- 161 unchanged lines hidden (view full) ---

932 struct in_addr alias_address;
933 struct in_addr original_address;
934 struct in_addr proxy_address;
935 u_short alias_port;
936 u_short proxy_port;
937 int accumulate;
938 u_short *sptr;
939
940/* Special processing for IP encoding protocols */
941 if (ntohs(tc->th_dport) == PPTP_CONTROL_PORT_NUMBER
942 || ntohs(tc->th_sport) == PPTP_CONTROL_PORT_NUMBER)
943 AliasHandlePptpIn(pip, link);
944
906 alias_address = GetAliasAddress(link);
907 original_address = GetOriginalAddress(link);
908 proxy_address = GetProxyAddress(link);
909 alias_port = tc->th_dport;
910 tc->th_dport = GetOriginalPort(link);
911 proxy_port = GetProxyPort(link);
912
913/* Adjust TCP checksum since destination port is being unaliased */

--- 151 unchanged lines hidden (view full) ---

1065
1066/* Monitor TCP connection state */
1067 TcpMonitorOut(pip, link);
1068
1069/* Special processing for IP encoding protocols */
1070 if (ntohs(tc->th_dport) == FTP_CONTROL_PORT_NUMBER
1071 || ntohs(tc->th_sport) == FTP_CONTROL_PORT_NUMBER)
1072 AliasHandleFtpOut(pip, link, maxpacketsize);
945 alias_address = GetAliasAddress(link);
946 original_address = GetOriginalAddress(link);
947 proxy_address = GetProxyAddress(link);
948 alias_port = tc->th_dport;
949 tc->th_dport = GetOriginalPort(link);
950 proxy_port = GetProxyPort(link);
951
952/* Adjust TCP checksum since destination port is being unaliased */

--- 151 unchanged lines hidden (view full) ---

1104
1105/* Monitor TCP connection state */
1106 TcpMonitorOut(pip, link);
1107
1108/* Special processing for IP encoding protocols */
1109 if (ntohs(tc->th_dport) == FTP_CONTROL_PORT_NUMBER
1110 || ntohs(tc->th_sport) == FTP_CONTROL_PORT_NUMBER)
1111 AliasHandleFtpOut(pip, link, maxpacketsize);
1073 if (ntohs(tc->th_dport) == IRC_CONTROL_PORT_NUMBER_1
1112 else if (ntohs(tc->th_dport) == IRC_CONTROL_PORT_NUMBER_1
1074 || ntohs(tc->th_dport) == IRC_CONTROL_PORT_NUMBER_2)
1075 AliasHandleIrcOut(pip, link, maxpacketsize);
1113 || ntohs(tc->th_dport) == IRC_CONTROL_PORT_NUMBER_2)
1114 AliasHandleIrcOut(pip, link, maxpacketsize);
1115 else if (ntohs(tc->th_dport) == PPTP_CONTROL_PORT_NUMBER
1116 || ntohs(tc->th_sport) == PPTP_CONTROL_PORT_NUMBER)
1117 AliasHandlePptpOut(pip, link);
1076
1077/* Adjust TCP checksum since source port is being aliased */
1078/* and source address is being altered */
1079 accumulate = tc->th_sport;
1080 tc->th_sport = alias_port;
1081 accumulate -= tc->th_sport;
1082
1083 sptr = (u_short *) &(pip->ip_src);

--- 212 unchanged lines hidden (view full) ---

1296 iresult = IcmpAliasIn(pip);
1297 break;
1298 case IPPROTO_UDP:
1299 iresult = UdpAliasIn(pip);
1300 break;
1301 case IPPROTO_TCP:
1302 iresult = TcpAliasIn(pip);
1303 break;
1118
1119/* Adjust TCP checksum since source port is being aliased */
1120/* and source address is being altered */
1121 accumulate = tc->th_sport;
1122 tc->th_sport = alias_port;
1123 accumulate -= tc->th_sport;
1124
1125 sptr = (u_short *) &(pip->ip_src);

--- 212 unchanged lines hidden (view full) ---

1338 iresult = IcmpAliasIn(pip);
1339 break;
1340 case IPPROTO_UDP:
1341 iresult = UdpAliasIn(pip);
1342 break;
1343 case IPPROTO_TCP:
1344 iresult = TcpAliasIn(pip);
1345 break;
1346 case IPPROTO_GRE:
1347 iresult = GreAliasIn(pip);
1348 break;
1304 default:
1305 iresult = ProtoAliasIn(pip);
1306 break;
1307 }
1308
1309 if (ntohs(pip->ip_off) & IP_MF)
1310 {
1311 struct alias_link *link;

--- 111 unchanged lines hidden --- 		1349 default:
1350 iresult = ProtoAliasIn(pip);
1351 break;
1352 }
1353
1354 if (ntohs(pip->ip_off) & IP_MF)
1355 {
1356 struct alias_link *link;

--- 111 unchanged lines hidden ---