alias_local.h revision 179480
1/*- 2 * Copyright (c) 2001 Charles Mott <cm@linktel.net> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/sys/netinet/libalias/alias_local.h 179480 2008-06-01 18:34:58Z mav $ 27 */ 28 29/* 30 * Alias_local.h contains the function prototypes for alias.c, 31 * alias_db.c, alias_util.c and alias_ftp.c, alias_irc.c (as well 32 * as any future add-ons). It also includes macros, globals and 33 * struct definitions shared by more than one alias*.c file. 34 * 35 * This include file is intended to be used only within the aliasing 36 * software. Outside world interfaces are defined in alias.h 37 * 38 * This software is placed into the public domain with no restrictions 39 * on its distribution. 40 * 41 * Initial version: August, 1996 (cjm) 42 * 43 * <updated several times by original author and Eivind Eklund> 44 */ 45 46#ifndef _ALIAS_LOCAL_H_ 47#define _ALIAS_LOCAL_H_ 48 49#include <sys/types.h> 50#include <sys/sysctl.h> 51 52#ifdef _KERNEL 53#include <sys/malloc.h> 54#include <sys/param.h> 55#include <sys/lock.h> 56#include <sys/mutex.h> 57 58/* XXX: LibAliasSetTarget() uses this constant. */ 59#define INADDR_NONE 0xffffffff 60#endif 61 62/* Sizes of input and output link tables */ 63#define LINK_TABLE_OUT_SIZE 4001 64#define LINK_TABLE_IN_SIZE 4001 65 66struct proxy_entry; 67 68struct libalias { 69 LIST_ENTRY(libalias) instancelist; 70 71 int packetAliasMode; /* Mode flags */ 72 /* - documented in alias.h */ 73 74 struct in_addr aliasAddress; /* Address written onto source */ 75 /* field of IP packet. */ 76 77 struct in_addr targetAddress; /* IP address incoming packets */ 78 /* are sent to if no aliasing */ 79 /* link already exists */ 80 81 struct in_addr nullAddress; /* Used as a dummy parameter for */ 82 /* some function calls */ 83 84 LIST_HEAD (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE]; 85 /* Lookup table of pointers to */ 86 /* chains of link records. Each */ 87 88 LIST_HEAD (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE]; 89 /* link record is doubly indexed */ 90 /* into input and output lookup */ 91 /* tables. */ 92 93 /* Link statistics */ 94 int icmpLinkCount; 95 int udpLinkCount; 96 int tcpLinkCount; 97 int pptpLinkCount; 98 int protoLinkCount; 99 int fragmentIdLinkCount; 100 int fragmentPtrLinkCount; 101 int sockCount; 102 103 int cleanupIndex; /* Index to chain of link table */ 104 /* being inspected for old links */ 105 106 int timeStamp; /* System time in seconds for */ 107 /* current packet */ 108 109 int lastCleanupTime; /* Last time 110 * IncrementalCleanup() */ 111 /* was called */ 112 113 int deleteAllLinks; /* If equal to zero, DeleteLink() */ 114 /* will not remove permanent links */ 115 116 /* log descriptor */ 117#ifdef _KERNEL 118 char *logDesc; 119#else 120 FILE *logDesc; 121#endif 122 /* statistics monitoring */ 123 124 int newDefaultLink; /* Indicates if a new aliasing */ 125 /* link has been created after a */ 126 /* call to PacketAliasIn/Out(). */ 127 128#ifndef NO_FW_PUNCH 129 int fireWallFD; /* File descriptor to be able to */ 130 /* control firewall. Opened by */ 131 /* PacketAliasSetMode on first */ 132 /* setting the PKT_ALIAS_PUNCH_FW */ 133 /* flag. */ 134 int fireWallBaseNum; /* The first firewall entry 135 * free for our use */ 136 int fireWallNumNums; /* How many entries can we 137 * use? */ 138 int fireWallActiveNum; /* Which entry did we last 139 * use? */ 140 char *fireWallField; /* bool array for entries */ 141#endif 142 143 unsigned int skinnyPort; /* TCP port used by the Skinny */ 144 /* protocol. */ 145 146 struct proxy_entry *proxyList; 147 148 struct in_addr true_addr; /* in network byte order. */ 149 u_short true_port; /* in host byte order. */ 150#ifdef _KERNEL 151 /* 152 * avoid races in libalias: every public function has to use it. 153 */ 154 struct mtx mutex; 155#endif 156}; 157 158/* Macros */ 159 160#ifdef _KERNEL 161#define LIBALIAS_LOCK_INIT(l) \ 162 mtx_init(&l->mutex, "per-instance libalias mutex", NULL, MTX_DEF) 163#define LIBALIAS_LOCK_ASSERT(l) mtx_assert(&l->mutex, MA_OWNED) 164#define LIBALIAS_LOCK(l) mtx_lock(&l->mutex) 165#define LIBALIAS_UNLOCK(l) mtx_unlock(&l->mutex) 166#define LIBALIAS_LOCK_DESTROY(l) mtx_destroy(&l->mutex) 167#else 168#define LIBALIAS_LOCK_INIT(l) 169#define LIBALIAS_LOCK_ASSERT(l) 170#define LIBALIAS_LOCK(l) 171#define LIBALIAS_UNLOCK(l) 172#define LIBALIAS_LOCK_DESTROY(l) 173#endif 174 175/* 176 * The following macro is used to update an 177 * internet checksum. "delta" is a 32-bit 178 * accumulation of all the changes to the 179 * checksum (adding in new 16-bit words and 180 * subtracting out old words), and "cksum" 181 * is the checksum value to be updated. 182 */ 183#define ADJUST_CHECKSUM(acc, cksum) \ 184 do { \ 185 acc += cksum; \ 186 if (acc < 0) { \ 187 acc = -acc; \ 188 acc = (acc >> 16) + (acc & 0xffff); \ 189 acc += acc >> 16; \ 190 cksum = (u_short) ~acc; \ 191 } else { \ 192 acc = (acc >> 16) + (acc & 0xffff); \ 193 acc += acc >> 16; \ 194 cksum = (u_short) acc; \ 195 } \ 196 } while (0) 197 198 199/* Prototypes */ 200 201/* 202 * We do not calculate TCP checksums when libalias is a kernel 203 * module, since it has no idea about checksum offloading. 204 * If TCP data has changed, then we just set checksum to zero, 205 * and caller must recalculate it himself. 206 * In case if libalias will edit UDP data, the same approach 207 * should be used. 208 */ 209#ifndef _KERNEL 210u_short IpChecksum(struct ip *_pip); 211u_short TcpChecksum(struct ip *_pip); 212#endif 213void 214DifferentialChecksum(u_short * _cksum, void * _new, void * _old, int _n); 215 216/* Internal data access */ 217struct alias_link * 218FindIcmpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 219 u_short _id_alias, int _create); 220struct alias_link * 221FindIcmpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 222 u_short _id, int _create); 223struct alias_link * 224FindFragmentIn1(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 225 u_short _ip_id); 226struct alias_link * 227FindFragmentIn2(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 228 u_short _ip_id); 229struct alias_link * 230 AddFragmentPtrLink(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 231struct alias_link * 232 FindFragmentPtr(struct libalias *la, struct in_addr _dst_addr, u_short _ip_id); 233struct alias_link * 234FindProtoIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 235 u_char _proto); 236struct alias_link * 237FindProtoOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 238 u_char _proto); 239struct alias_link * 240FindUdpTcpIn(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 241 u_short _dst_port, u_short _alias_port, u_char _proto, int _create); 242struct alias_link * 243FindUdpTcpOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 244 u_short _src_port, u_short _dst_port, u_char _proto, int _create); 245struct alias_link * 246AddPptp(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 247 struct in_addr _alias_addr, u_int16_t _src_call_id); 248struct alias_link * 249FindPptpOutByCallId(struct libalias *la, struct in_addr _src_addr, 250 struct in_addr _dst_addr, u_int16_t _src_call_id); 251struct alias_link * 252FindPptpInByCallId(struct libalias *la, struct in_addr _dst_addr, 253 struct in_addr _alias_addr, u_int16_t _dst_call_id); 254struct alias_link * 255FindPptpOutByPeerCallId(struct libalias *la, struct in_addr _src_addr, 256 struct in_addr _dst_addr, u_int16_t _dst_call_id); 257struct alias_link * 258FindPptpInByPeerCallId(struct libalias *la, struct in_addr _dst_addr, 259 struct in_addr _alias_addr, u_int16_t _alias_call_id); 260struct alias_link * 261FindRtspOut(struct libalias *la, struct in_addr _src_addr, struct in_addr _dst_addr, 262 u_short _src_port, u_short _alias_port, u_char _proto); 263struct in_addr 264 FindOriginalAddress(struct libalias *la, struct in_addr _alias_addr); 265struct in_addr 266 FindAliasAddress(struct libalias *la, struct in_addr _original_addr); 267 268/* External data access/modification */ 269int 270FindNewPortGroup(struct libalias *la, struct in_addr _dst_addr, struct in_addr _alias_addr, 271 u_short _src_port, u_short _dst_port, u_short _port_count, 272 u_char _proto, u_char _align); 273void GetFragmentAddr(struct alias_link *_lnk, struct in_addr *_src_addr); 274void SetFragmentAddr(struct alias_link *_lnk, struct in_addr _src_addr); 275void GetFragmentPtr(struct alias_link *_lnk, char **_fptr); 276void SetFragmentPtr(struct alias_link *_lnk, char *fptr); 277void SetStateIn(struct alias_link *_lnk, int _state); 278void SetStateOut(struct alias_link *_lnk, int _state); 279int GetStateIn (struct alias_link *_lnk); 280int GetStateOut(struct alias_link *_lnk); 281struct in_addr 282 GetOriginalAddress(struct alias_link *_lnk); 283struct in_addr 284 GetDestAddress(struct alias_link *_lnk); 285struct in_addr 286 GetAliasAddress(struct alias_link *_lnk); 287struct in_addr 288 GetDefaultAliasAddress(struct libalias *la); 289void SetDefaultAliasAddress(struct libalias *la, struct in_addr _alias_addr); 290u_short GetOriginalPort(struct alias_link *_lnk); 291u_short GetAliasPort(struct alias_link *_lnk); 292struct in_addr 293 GetProxyAddress(struct alias_link *_lnk); 294void SetProxyAddress(struct alias_link *_lnk, struct in_addr _addr); 295u_short GetProxyPort(struct alias_link *_lnk); 296void SetProxyPort(struct alias_link *_lnk, u_short _port); 297void SetAckModified(struct alias_link *_lnk); 298int GetAckModified(struct alias_link *_lnk); 299int GetDeltaAckIn(u_long, struct alias_link *_lnk); 300int GetDeltaSeqOut(u_long, struct alias_link *lnk); 301void AddSeq(struct alias_link *lnk, int delta, u_int ip_hl, 302 u_short ip_len, u_long th_seq, u_int th_off); 303void SetExpire (struct alias_link *_lnk, int _expire); 304void ClearCheckNewLink(struct libalias *la); 305void SetProtocolFlags(struct alias_link *_lnk, int _pflags); 306int GetProtocolFlags(struct alias_link *_lnk); 307void SetDestCallId(struct alias_link *_lnk, u_int16_t _cid); 308 309#ifndef NO_FW_PUNCH 310void PunchFWHole(struct alias_link *_lnk); 311 312#endif 313 314/* Housekeeping function */ 315void HouseKeeping(struct libalias *); 316 317/* Tcp specfic routines */ 318/* lint -save -library Suppress flexelint warnings */ 319 320/* Transparent proxy routines */ 321int 322ProxyCheck(struct libalias *la, struct in_addr *proxy_server_addr, 323 u_short * proxy_server_port, struct in_addr src_addr, 324 struct in_addr dst_addr, u_short dst_port, u_char ip_p); 325void 326ProxyModify(struct libalias *la, struct alias_link *_lnk, struct ip *_pip, 327 int _maxpacketsize, int _proxy_type); 328 329enum alias_tcp_state { 330 ALIAS_TCP_STATE_NOT_CONNECTED, 331 ALIAS_TCP_STATE_CONNECTED, 332 ALIAS_TCP_STATE_DISCONNECTED 333}; 334 335#if defined(_NETINET_IP_H_) 336static __inline void * 337ip_next(struct ip *iphdr) 338{ 339 char *p = (char *)iphdr; 340 return (&p[iphdr->ip_hl * 4]); 341} 342#endif 343 344#if defined(_NETINET_TCP_H_) 345static __inline void * 346tcp_next(struct tcphdr *tcphdr) 347{ 348 char *p = (char *)tcphdr; 349 return (&p[tcphdr->th_off * 4]); 350} 351#endif 352 353#if defined(_NETINET_UDP_H_) 354static __inline void * 355udp_next(struct udphdr *udphdr) 356{ 357 return ((void *)(udphdr + 1)); 358} 359#endif 360 361#endif /* !_ALIAS_LOCAL_H_ */ 362