1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2001 Charles Mott <cm@linktel.net> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31/* 32 * Alias_local.h contains the function prototypes for alias.c, 33 * alias_db.c, alias_util.c and alias_ftp.c, alias_irc.c (as well 34 * as any future add-ons). It also includes macros, globals and 35 * struct definitions shared by more than one alias*.c file. 36 * 37 * This include file is intended to be used only within the aliasing 38 * software. Outside world interfaces are defined in alias.h 39 * 40 * This software is placed into the public domain with no restrictions 41 * on its distribution. 42 * 43 * Initial version: August, 1996 (cjm) 44 * 45 * <updated several times by original author and Eivind Eklund> 46 */ 47 48#ifndef _ALIAS_LOCAL_H_ 49#define _ALIAS_LOCAL_H_ 50 51#include <sys/types.h> 52#include <sys/sysctl.h> 53 54#ifdef _KERNEL 55#include <sys/malloc.h> 56#include <sys/param.h> 57#include <sys/lock.h> 58#include <sys/mutex.h> 59 60/* XXX: LibAliasSetTarget() uses this constant. */ 61#define INADDR_NONE 0xffffffff 62 63#include <netinet/libalias/alias_sctp.h> 64#else 65#include "alias_sctp.h" 66#endif 67 68/* Sizes of input and output link tables */ 69#define LINK_TABLE_OUT_SIZE 4001 70#define LINK_TABLE_IN_SIZE 4001 71 72#define GET_ALIAS_PORT -1 73#define GET_ALIAS_ID GET_ALIAS_PORT 74 75#ifdef _KERNEL 76#define INET_NTOA_BUF(buf) (buf) 77#else 78#define INET_NTOA_BUF(buf) (buf), sizeof(buf) 79#endif 80 81struct proxy_entry; 82 83struct libalias { 84 LIST_ENTRY(libalias) instancelist; 85 /* Mode flags documented in alias.h */ 86 int packetAliasMode; 87 /* Address written onto source field of IP packet. */ 88 struct in_addr aliasAddress; 89 /* IP address incoming packets are sent to 90 * if no aliasing link already exists */ 91 struct in_addr targetAddress; 92 /* Lookup table of pointers to chains of link records. 93 * Each link record is doubly indexed into input and 94 * output lookup tables. */ 95 LIST_HEAD (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE]; 96 LIST_HEAD (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE]; 97 /* Link statistics */ 98 int icmpLinkCount; 99 int udpLinkCount; 100 int tcpLinkCount; 101 int pptpLinkCount; 102 int protoLinkCount; 103 int fragmentIdLinkCount; 104 int fragmentPtrLinkCount; 105 int sockCount; 106 /* Index to chain of link table being inspected for old links */ 107 int cleanupIndex; 108 /* System time in seconds for current packet */ 109 int timeStamp; 110 /* Last time IncrementalCleanup() was called */ 111 int lastCleanupTime; 112 /* If equal to zero, DeleteLink() 113 * will not remove permanent links */ 114 int deleteAllLinks; 115 /* log descriptor */ 116#ifdef _KERNEL 117 char *logDesc; 118#else 119 FILE *logDesc; 120#endif 121 122#ifndef NO_FW_PUNCH 123 /* File descriptor to be able to control firewall. 124 * Opened by PacketAliasSetMode on first setting 125 * the PKT_ALIAS_PUNCH_FW flag. */ 126 int fireWallFD; 127 /* The first firewall entry free for our use */ 128 int fireWallBaseNum; 129 /* How many entries can we use? */ 130 int fireWallNumNums; 131 /* Which entry did we last use? */ 132 int fireWallActiveNum; 133 /* bool array for entries */ 134 char *fireWallField; 135#endif 136 /* TCP port used by the Skinny protocol. */ 137 unsigned int skinnyPort; 138 139 struct proxy_entry *proxyList; 140 141 struct in_addr true_addr; /* in network byte order. */ 142 u_short true_port; /* in host byte order. */ 143 144 /* Port ranges for aliasing. */ 145 u_short aliasPortLower; 146 u_short aliasPortLength; 147 148 /* 149 * sctp code support 150 */ 151 152 /* counts associations that have progressed to UP and not yet removed */ 153 int sctpLinkCount; 154#ifdef _KERNEL 155 /* timing queue for keeping track of association timeouts */ 156 struct sctp_nat_timer sctpNatTimer; 157 /* size of hash table used in this instance */ 158 u_int sctpNatTableSize; 159 /* local look up table sorted by l_vtag/l_port */ 160 LIST_HEAD(sctpNatTableL, sctp_nat_assoc) *sctpTableLocal; 161 /* global look up table sorted by g_vtag/g_port */ 162 LIST_HEAD(sctpNatTableG, sctp_nat_assoc) *sctpTableGlobal; 163 164 /* avoid races in libalias: every public function has to use it. */ 165 struct mtx mutex; 166#endif 167}; 168 169/* Macros */ 170 171#ifdef _KERNEL 172#define LIBALIAS_LOCK_INIT(l) \ 173 mtx_init(&l->mutex, "per-instance libalias mutex", NULL, MTX_DEF) 174#define LIBALIAS_LOCK_ASSERT(l) mtx_assert(&l->mutex, MA_OWNED) 175#define LIBALIAS_LOCK(l) mtx_lock(&l->mutex) 176#define LIBALIAS_UNLOCK(l) mtx_unlock(&l->mutex) 177#define LIBALIAS_LOCK_DESTROY(l) mtx_destroy(&l->mutex) 178#else 179#define LIBALIAS_LOCK_INIT(l) 180#define LIBALIAS_LOCK_ASSERT(l) 181#define LIBALIAS_LOCK(l) 182#define LIBALIAS_UNLOCK(l) 183#define LIBALIAS_LOCK_DESTROY(l) 184#endif 185 186/* 187 * The following macro is used to update an 188 * internet checksum. "delta" is a 32-bit 189 * accumulation of all the changes to the 190 * checksum (adding in new 16-bit words and 191 * subtracting out old words), and "cksum" 192 * is the checksum value to be updated. 193 */ 194#define ADJUST_CHECKSUM(acc, cksum) \ 195 do { \ 196 acc += cksum; \ 197 if (acc < 0) { \ 198 acc = -acc; \ 199 acc = (acc >> 16) + (acc & 0xffff); \ 200 acc += acc >> 16; \ 201 cksum = (u_short) ~acc; \ 202 } else { \ 203 acc = (acc >> 16) + (acc & 0xffff); \ 204 acc += acc >> 16; \ 205 cksum = (u_short) acc; \ 206 } \ 207 } while (0) 208 209/* Prototypes */ 210 211/* 212 * SctpFunction prototypes 213 * 214 */ 215void AliasSctpInit(struct libalias *la); 216void AliasSctpTerm(struct libalias *la); 217int SctpAlias(struct libalias *la, struct ip *ip, int direction); 218 219/* 220 * We do not calculate TCP checksums when libalias is a kernel 221 * module, since it has no idea about checksum offloading. 222 * If TCP data has changed, then we just set checksum to zero, 223 * and caller must recalculate it himself. 224 * In case if libalias will edit UDP data, the same approach 225 * should be used. 226 */ 227#ifndef _KERNEL 228u_short IpChecksum(struct ip *_pip); 229u_short TcpChecksum(struct ip *_pip); 230#endif 231void 232DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n); 233 234/* Internal data access */ 235struct alias_link * 236AddLink(struct libalias *la, struct in_addr src_addr, struct in_addr dst_addr, 237 struct in_addr alias_addr, u_short src_port, u_short dst_port, 238 int alias_param, int link_type); 239struct alias_link * 240FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 241 u_short _id_alias, int _create); 242struct alias_link * 243FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 244 u_short _id, int _create); 245struct alias_link * 246FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 247 u_short _ip_id); 248struct alias_link * 249FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 250 u_short _ip_id); 251struct alias_link * 252AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 253struct alias_link * 254FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 255struct alias_link * 256FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 257 u_char _proto); 258struct alias_link * 259FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 260 u_char _proto); 261struct alias_link * 262FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 263 u_short _dst_port, u_short _alias_port, u_char _proto, int _create); 264struct alias_link * 265FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 266 u_short _src_port, u_short _dst_port, u_char _proto, int _create); 267struct alias_link * 268AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 269 struct in_addr _alias_addr, u_int16_t _src_call_id); 270struct alias_link * 271FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr, 272 struct in_addr _dst_addr, u_int16_t _src_call_id); 273struct alias_link * 274FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr, 275 struct in_addr _alias_addr, u_int16_t _dst_call_id); 276struct alias_link * 277FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr, 278 struct in_addr _dst_addr, u_int16_t _dst_call_id); 279struct alias_link * 280FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr, 281 struct in_addr _alias_addr, u_int16_t _alias_call_id); 282struct alias_link * 283FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 284 u_short _src_port, u_short _alias_port, u_char _proto); 285struct in_addr 286FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr); 287struct in_addr 288FindAliasAddress(struct libalias *la, struct in_addr _original_addr); 289struct in_addr 290FindSctpRedirectAddress(struct libalias *la, struct sctp_nat_msg *sm); 291 292/* External data access/modification */ 293int FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, 294 struct in_addr _alias_addr, u_short _src_port, 295 u_short _dst_port, u_short _port_count, u_char _proto, 296 u_char _align); 297void GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr); 298void SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr); 299void GetFragmentPtr(struct alias_link *_lnk, void **_fptr); 300void SetFragmentPtr(struct alias_link *_lnk, void *fptr); 301void SetStateIn(struct alias_link *_lnk, int _state); 302void SetStateOut(struct alias_link *_lnk, int _state); 303int GetStateIn (struct alias_link *_lnk); 304int GetStateOut(struct alias_link *_lnk); 305struct in_addr GetOriginalAddress(struct alias_link *_lnk); 306struct in_addr GetDestAddress(struct alias_link *_lnk); 307struct in_addr GetAliasAddress(struct alias_link *_lnk); 308struct in_addr GetDefaultAliasAddress(struct libalias *la); 309void SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr); 310u_short GetOriginalPort(struct alias_link *_lnk); 311u_short GetAliasPort(struct alias_link *_lnk); 312struct in_addr GetProxyAddress(struct alias_link *_lnk); 313void SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr); 314u_short GetProxyPort(struct alias_link *_lnk); 315void SetProxyPort(struct alias_link *_lnk, u_short _port); 316void SetAckModified(struct alias_link *_lnk); 317int GetAckModified(struct alias_link *_lnk); 318int GetDeltaAckIn(u_long, struct alias_link *_lnk); 319int GetDeltaSeqOut(u_long, struct alias_link *lnk); 320void AddSeq(struct alias_link *lnk, int delta, u_int ip_hl, 321 u_short ip_len, u_long th_seq, u_int th_off); 322void SetExpire (struct alias_link *_lnk, int _expire); 323void SetProtocolFlags(struct alias_link *_lnk, int _pflags); 324int GetProtocolFlags(struct alias_link *_lnk); 325void SetDestCallId(struct alias_link *_lnk, u_int16_t _cid); 326 327#ifndef NO_FW_PUNCH 328void PunchFWHole(struct alias_link *_lnk); 329 330#endif 331 332/* Housekeeping function */ 333void HouseKeeping(struct libalias *); 334 335/* Transparent proxy routines */ 336int 337ProxyCheck(struct libalias *la, struct in_addr *proxy_server_addr, 338 u_short * proxy_server_port, struct in_addr src_addr, 339 struct in_addr dst_addr, u_short dst_port, u_char ip_p); 340void 341ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip, 342 int _maxpacketsize, int _proxy_type); 343 344/* Tcp specific routines */ 345/* lint -save -library Suppress flexelint warnings */ 346 347enum alias_tcp_state { 348 ALIAS_TCP_STATE_NOT_CONNECTED, 349 ALIAS_TCP_STATE_CONNECTED, 350 ALIAS_TCP_STATE_DISCONNECTED 351}; 352 353#if defined(_NETINET_IP_H_) 354static __inline void * 355ip_next(struct ip *iphdr) 356{ 357 char *p = (char *)iphdr; 358 return (&p[iphdr->ip_hl * 4]); 359} 360#endif 361 362#if defined(_NETINET_TCP_H_) 363static __inline void * 364tcp_next(struct tcphdr *tcphdr) 365{ 366 char *p = (char *)tcphdr; 367 return (&p[tcphdr->th_off * 4]); 368} 369#endif 370 371#if defined(_NETINET_UDP_H_) 372static __inline void * 373udp_next(struct udphdr *udphdr) 374{ 375 return ((void *)(udphdr + 1)); 376} 377#endif 378 379#endif /* !_ALIAS_LOCAL_H_ */ 380