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/tree.h> 52 #include <sys/types.h> 53 #include <sys/sysctl.h> 54 55 #ifdef _KERNEL 56 #include <sys/malloc.h> 57 #include <sys/param.h> 58 #include <sys/lock.h> 59 #include <sys/mutex.h> 60 61 /* XXX: LibAliasSetTarget() uses this constant. */ 62 #define INADDR_NONE 0xffffffff 63 64 #include <netinet/libalias/alias_sctp.h> 65 #else 66 #include "alias_sctp.h" 67 #endif 68 69 /* Sizes of input and output link tables */ 70 #define GET_ALIAS_PORT -1 71 #define GET_ALIAS_ID GET_ALIAS_PORT 72 73 #ifdef _KERNEL 74 #define INET_NTOA_BUF(buf) (buf) 75 #else 76 #define INET_NTOA_BUF(buf) (buf), sizeof(buf) 77 #endif 78 79 struct proxy_entry; 80 81 struct group_in { 82 struct in_addr alias_addr; 83 u_short alias_port; 84 int link_type; 85 SPLAY_ENTRY(group_in) in; 86 LIST_HEAD(, alias_link) full, partial; 87 }; 88 89 struct libalias { 90 LIST_ENTRY(libalias) instancelist; 91 /* Mode flags documented in alias.h */ 92 int packetAliasMode; 93 /* Address written onto source field of IP packet. */ 94 struct in_addr aliasAddress; 95 /* IP address incoming packets are sent to 96 * if no aliasing link already exists */ 97 struct in_addr targetAddress; 98 /* Lookup table of pointers to chains of link records. 99 * Each link record is doubly indexed into input and 100 * output lookup tables. */ 101 SPLAY_HEAD(splay_out, alias_link) linkSplayOut; 102 SPLAY_HEAD(splay_in, group_in) linkSplayIn; 103 LIST_HEAD (, alias_link) pptpList; 104 /* HouseKeeping */ 105 TAILQ_HEAD (, alias_link) checkExpire; 106 /* Link statistics */ 107 unsigned int icmpLinkCount; 108 unsigned int udpLinkCount; 109 unsigned int tcpLinkCount; 110 unsigned int pptpLinkCount; 111 unsigned int protoLinkCount; 112 unsigned int fragmentIdLinkCount; 113 unsigned int fragmentPtrLinkCount; 114 unsigned int sockCount; 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 /* System time in seconds for current packet */ 212 extern int LibAliasTime; 213 214 /* 215 * SctpFunction prototypes 216 * 217 */ 218 void AliasSctpInit(struct libalias *la); 219 void AliasSctpTerm(struct libalias *la); 220 int SctpAlias(struct libalias *la, struct ip *ip, int direction); 221 222 /* 223 * We do not calculate TCP checksums when libalias is a kernel 224 * module, since it has no idea about checksum offloading. 225 * If TCP data has changed, then we just set checksum to zero, 226 * and caller must recalculate it himself. 227 * In case if libalias will edit UDP data, the same approach 228 * should be used. 229 */ 230 #ifndef _KERNEL 231 u_short IpChecksum(struct ip *_pip); 232 u_short TcpChecksum(struct ip *_pip); 233 #endif 234 void 235 DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n); 236 237 /* Internal data access */ 238 struct alias_link * 239 AddLink(struct libalias *la, struct in_addr src_addr, struct in_addr dst_addr, 240 struct in_addr alias_addr, u_short src_port, u_short dst_port, 241 int alias_param, int link_type); 242 struct alias_link * 243 FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 244 u_short _id_alias, int _create); 245 struct alias_link * 246 FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 247 u_short _id, int _create); 248 struct alias_link * 249 FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 250 u_short _ip_id); 251 struct alias_link * 252 FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 253 u_short _ip_id); 254 struct alias_link * 255 AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 256 struct alias_link * 257 FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 258 struct alias_link * 259 FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 260 u_char _proto); 261 struct alias_link * 262 FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 263 u_char _proto); 264 struct alias_link * 265 FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 266 u_short _dst_port, u_short _alias_port, u_char _proto, int _create); 267 struct alias_link * 268 FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 269 u_short _src_port, u_short _dst_port, u_char _proto, int _create); 270 struct alias_link * 271 AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 272 struct in_addr _alias_addr, u_int16_t _src_call_id); 273 struct alias_link * 274 FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr, 275 struct in_addr _dst_addr, u_int16_t _src_call_id); 276 struct alias_link * 277 FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr, 278 struct in_addr _alias_addr, u_int16_t _dst_call_id); 279 struct alias_link * 280 FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr, 281 struct in_addr _dst_addr, u_int16_t _dst_call_id); 282 struct alias_link * 283 FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr, 284 struct in_addr _alias_addr, u_int16_t _alias_call_id); 285 struct alias_link * 286 FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 287 u_short _src_port, u_short _alias_port, u_char _proto); 288 struct in_addr 289 FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr); 290 struct in_addr 291 FindAliasAddress(struct libalias *la, struct in_addr _original_addr); 292 struct in_addr 293 FindSctpRedirectAddress(struct libalias *la, struct sctp_nat_msg *sm); 294 295 /* External data access/modification */ 296 int FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, 297 struct in_addr _alias_addr, u_short _src_port, 298 u_short _dst_port, u_short _port_count, u_char _proto, 299 u_char _align); 300 void GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr); 301 void SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr); 302 void GetFragmentPtr(struct alias_link *_lnk, void **_fptr); 303 void SetFragmentPtr(struct alias_link *_lnk, void *fptr); 304 void SetStateIn(struct alias_link *_lnk, int _state); 305 void SetStateOut(struct alias_link *_lnk, int _state); 306 int GetStateIn (struct alias_link *_lnk); 307 int GetStateOut(struct alias_link *_lnk); 308 struct in_addr GetOriginalAddress(struct alias_link *_lnk); 309 struct in_addr GetDestAddress(struct alias_link *_lnk); 310 struct in_addr GetAliasAddress(struct alias_link *_lnk); 311 struct in_addr GetDefaultAliasAddress(struct libalias *la); 312 void SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr); 313 u_short GetOriginalPort(struct alias_link *_lnk); 314 u_short GetAliasPort(struct alias_link *_lnk); 315 struct in_addr GetProxyAddress(struct alias_link *_lnk); 316 void SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr); 317 u_short GetProxyPort(struct alias_link *_lnk); 318 void SetProxyPort(struct alias_link *_lnk, u_short _port); 319 void SetAckModified(struct alias_link *_lnk); 320 int GetAckModified(struct alias_link *_lnk); 321 int GetDeltaAckIn(u_long, struct alias_link *_lnk); 322 int GetDeltaSeqOut(u_long, struct alias_link *lnk); 323 void AddSeq(struct alias_link *lnk, int delta, u_int ip_hl, 324 u_short ip_len, u_long th_seq, u_int th_off); 325 void SetExpire (struct alias_link *_lnk, int _expire); 326 void SetProtocolFlags(struct alias_link *_lnk, int _pflags); 327 int GetProtocolFlags(struct alias_link *_lnk); 328 void SetDestCallId(struct alias_link *_lnk, u_int16_t _cid); 329 330 #ifndef NO_FW_PUNCH 331 void PunchFWHole(struct alias_link *_lnk); 332 333 #endif 334 335 /* Housekeeping function */ 336 void HouseKeeping(struct libalias *); 337 338 /* Transparent proxy routines */ 339 int 340 ProxyCheck(struct libalias *la, struct in_addr *proxy_server_addr, 341 u_short * proxy_server_port, struct in_addr src_addr, 342 struct in_addr dst_addr, u_short dst_port, u_char ip_p); 343 void 344 ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip, 345 int _maxpacketsize, int _proxy_type); 346 347 /* Tcp specific routines */ 348 /* lint -save -library Suppress flexelint warnings */ 349 350 enum alias_tcp_state { 351 ALIAS_TCP_STATE_NOT_CONNECTED, 352 ALIAS_TCP_STATE_CONNECTED, 353 ALIAS_TCP_STATE_DISCONNECTED 354 }; 355 356 #if defined(_NETINET_IP_H_) 357 static __inline void * 358 ip_next(struct ip *iphdr) 359 { 360 char *p = (char *)iphdr; 361 return (&p[iphdr->ip_hl * 4]); 362 } 363 #endif 364 365 #if defined(_NETINET_TCP_H_) 366 static __inline void * 367 tcp_next(struct tcphdr *tcphdr) 368 { 369 char *p = (char *)tcphdr; 370 return (&p[tcphdr->th_off * 4]); 371 } 372 #endif 373 374 #if defined(_NETINET_UDP_H_) 375 static __inline void * 376 udp_next(struct udphdr *udphdr) 377 { 378 return ((void *)(udphdr + 1)); 379 } 380 #endif 381 382 #endif /* !_ALIAS_LOCAL_H_ */ 383