2 * Copyright (c) 2001 Charles Mott <cm@linktel.net>
3 * Brian Somers <brian@Awfulhak.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * $FreeBSD: src/usr.sbin/ppp/nat_cmd.c,v 1.35.2.13 2002/09/01 02:12:29 brian Exp $
28 * $DragonFly: src/usr.sbin/ppp/nat_cmd.c,v 1.2 2003/06/17 04:30:00 dillon Exp $
31 #include <sys/param.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
35 #include <netinet/in_systm.h>
36 #include <netinet/in.h>
37 #include <netinet/ip.h>
38 #include <sys/socket.h>
59 #include "descriptor.h"
63 #include "slcompress.h"
64 #include "throughput.h"
85 #define NAT_EXTRABUF (13)
87 static int StrToAddr(const char *, struct in_addr *);
88 static int StrToPortRange(const char *, u_short *, u_short *, const char *);
89 static int StrToAddrAndPort(const char *, struct in_addr *, u_short *,
90 u_short *, const char *);
93 lowhigh(u_short *a, u_short *b)
105 nat_RedirectPort(struct cmdargs const *arg)
107 if (!arg->bundle->NatEnabled) {
108 prompt_Printf(arg->prompt, "Alias not enabled\n");
110 } else if (arg->argc == arg->argn + 3 || arg->argc == arg->argn + 4) {
113 struct in_addr localaddr;
114 u_short hlocalport, llocalport;
115 struct in_addr aliasaddr;
116 u_short haliasport, laliasport;
117 struct in_addr remoteaddr;
118 u_short hremoteport, lremoteport;
119 struct alias_link *link;
122 proto = arg->argv[arg->argn];
123 if (strcmp(proto, "tcp") == 0) {
124 proto_constant = IPPROTO_TCP;
125 } else if (strcmp(proto, "udp") == 0) {
126 proto_constant = IPPROTO_UDP;
128 prompt_Printf(arg->prompt, "port redirect: protocol must be"
133 error = StrToAddrAndPort(arg->argv[arg->argn+1], &localaddr, &llocalport,
136 prompt_Printf(arg->prompt, "nat port: error reading localaddr:port\n");
140 error = StrToPortRange(arg->argv[arg->argn+2], &laliasport, &haliasport,
143 prompt_Printf(arg->prompt, "nat port: error reading alias port\n");
146 aliasaddr.s_addr = INADDR_ANY;
148 if (arg->argc == arg->argn + 4) {
149 error = StrToAddrAndPort(arg->argv[arg->argn+3], &remoteaddr,
150 &lremoteport, &hremoteport, proto);
152 prompt_Printf(arg->prompt, "nat port: error reading "
153 "remoteaddr:port\n");
157 remoteaddr.s_addr = INADDR_ANY;
158 lremoteport = hremoteport = 0;
161 lowhigh(&llocalport, &hlocalport);
162 lowhigh(&laliasport, &haliasport);
163 lowhigh(&lremoteport, &hremoteport);
165 if (haliasport - laliasport != hlocalport - llocalport) {
166 prompt_Printf(arg->prompt, "nat port: local & alias port ranges "
171 if (hremoteport && hremoteport - lremoteport != hlocalport - llocalport) {
172 prompt_Printf(arg->prompt, "nat port: local & remote port ranges "
177 while (laliasport <= haliasport) {
178 link = PacketAliasRedirectPort(localaddr, htons(llocalport),
179 remoteaddr, htons(lremoteport),
180 aliasaddr, htons(laliasport),
184 prompt_Printf(arg->prompt, "nat port: %d: error %d\n", laliasport,
202 nat_RedirectAddr(struct cmdargs const *arg)
204 if (!arg->bundle->NatEnabled) {
205 prompt_Printf(arg->prompt, "nat not enabled\n");
207 } else if (arg->argc == arg->argn+2) {
209 struct in_addr localaddr, aliasaddr;
210 struct alias_link *link;
212 error = StrToAddr(arg->argv[arg->argn], &localaddr);
214 prompt_Printf(arg->prompt, "address redirect: invalid local address\n");
217 error = StrToAddr(arg->argv[arg->argn+1], &aliasaddr);
219 prompt_Printf(arg->prompt, "address redirect: invalid alias address\n");
220 prompt_Printf(arg->prompt, "usage: nat %s %s\n", arg->cmd->name,
224 link = PacketAliasRedirectAddr(localaddr, aliasaddr);
226 prompt_Printf(arg->prompt, "address redirect: packet aliasing"
228 prompt_Printf(arg->prompt, "usage: nat %s %s\n", arg->cmd->name,
239 nat_RedirectProto(struct cmdargs const *arg)
241 if (!arg->bundle->NatEnabled) {
242 prompt_Printf(arg->prompt, "nat not enabled\n");
244 } else if (arg->argc >= arg->argn + 2 && arg->argc <= arg->argn + 4) {
245 struct in_addr localIP, publicIP, remoteIP;
246 struct alias_link *link;
250 len = strlen(arg->argv[arg->argn]);
252 prompt_Printf(arg->prompt, "proto redirect: invalid protocol\n");
255 if (strspn(arg->argv[arg->argn], "01234567") == len)
256 pe = getprotobynumber(atoi(arg->argv[arg->argn]));
258 pe = getprotobyname(arg->argv[arg->argn]);
260 prompt_Printf(arg->prompt, "proto redirect: invalid protocol\n");
264 error = StrToAddr(arg->argv[arg->argn + 1], &localIP);
266 prompt_Printf(arg->prompt, "proto redirect: invalid src address\n");
270 if (arg->argc >= arg->argn + 3) {
271 error = StrToAddr(arg->argv[arg->argn + 2], &publicIP);
273 prompt_Printf(arg->prompt, "proto redirect: invalid alias address\n");
274 prompt_Printf(arg->prompt, "usage: nat %s %s\n", arg->cmd->name,
279 publicIP.s_addr = INADDR_ANY;
281 if (arg->argc == arg->argn + 4) {
282 error = StrToAddr(arg->argv[arg->argn + 2], &remoteIP);
284 prompt_Printf(arg->prompt, "proto redirect: invalid dst address\n");
285 prompt_Printf(arg->prompt, "usage: nat %s %s\n", arg->cmd->name,
290 remoteIP.s_addr = INADDR_ANY;
292 link = PacketAliasRedirectProto(localIP, remoteIP, publicIP, pe->p_proto);
294 prompt_Printf(arg->prompt, "proto redirect: packet aliasing"
296 prompt_Printf(arg->prompt, "usage: nat %s %s\n", arg->cmd->name,
307 StrToAddr(const char *str, struct in_addr *addr)
311 if (inet_aton(str, addr))
314 hp = gethostbyname(str);
316 log_Printf(LogWARN, "StrToAddr: Unknown host %s.\n", str);
319 *addr = *((struct in_addr *) hp->h_addr);
325 StrToPort(const char *str, u_short *port, const char *proto)
330 *port = strtol(str, &end, 10);
332 sp = getservbyname(str, proto);
334 log_Printf(LogWARN, "StrToAddr: Unknown port or service %s/%s.\n",
338 *port = ntohs(sp->s_port);
345 StrToPortRange(const char *str, u_short *low, u_short *high, const char *proto)
350 minus = strchr(str, '-');
352 *minus = '\0'; /* Cheat the const-ness ! */
354 res = StrToPort(str, low, proto);
357 *minus = '-'; /* Cheat the const-ness ! */
361 res = StrToPort(minus + 1, high, proto);
370 StrToAddrAndPort(const char *str, struct in_addr *addr, u_short *low,
371 u_short *high, const char *proto)
376 colon = strchr(str, ':');
378 log_Printf(LogWARN, "StrToAddrAndPort: %s is missing port number.\n", str);
382 *colon = '\0'; /* Cheat the const-ness ! */
383 res = StrToAddr(str, addr);
384 *colon = ':'; /* Cheat the const-ness ! */
388 return StrToPortRange(colon + 1, low, high, proto);
392 nat_ProxyRule(struct cmdargs const *arg)
398 if (arg->argn >= arg->argc)
401 for (f = arg->argn, pos = 0; f < arg->argc; f++) {
402 len = strlen(arg->argv[f]);
403 if (sizeof cmd - pos < len + (len ? 1 : 0))
407 strcpy(cmd + pos, arg->argv[f]);
411 return PacketAliasProxyRule(cmd);
415 nat_SetTarget(struct cmdargs const *arg)
419 if (arg->argc == arg->argn) {
420 addr.s_addr = INADDR_ANY;
421 PacketAliasSetTarget(addr);
425 if (arg->argc != arg->argn + 1)
428 if (!strcasecmp(arg->argv[arg->argn], "MYADDR")) {
429 addr.s_addr = INADDR_ANY;
430 PacketAliasSetTarget(addr);
434 addr = GetIpAddr(arg->argv[arg->argn]);
435 if (addr.s_addr == INADDR_NONE) {
436 log_Printf(LogWARN, "%s: invalid address\n", arg->argv[arg->argn]);
440 PacketAliasSetTarget(addr);
446 nat_PunchFW(struct cmdargs const *arg)
451 if (arg->argc == arg->argn) {
452 PacketAliasSetMode(0, PKT_ALIAS_PUNCH_FW);
456 if (arg->argc != arg->argn + 2)
459 base = strtol(arg->argv[arg->argn], &end, 10);
460 if (*end != '\0' || base < 0)
463 count = strtol(arg->argv[arg->argn + 1], &end, 10);
464 if (*end != '\0' || count < 0)
467 PacketAliasSetFWBase(base, count);
468 PacketAliasSetMode(PKT_ALIAS_PUNCH_FW, PKT_ALIAS_PUNCH_FW);
475 nat_LayerPush(struct bundle *bundle, struct link *l, struct mbuf *bp,
476 int pri, u_short *proto)
478 if (!bundle->NatEnabled || *proto != PROTO_IP)
481 log_Printf(LogDEBUG, "nat_LayerPush: PROTO_IP -> PROTO_IP\n");
482 m_settype(bp, MB_NATOUT);
483 /* Ensure there's a bit of extra buffer for the NAT code... */
484 bp = m_pullup(m_append(bp, NULL, NAT_EXTRABUF));
485 PacketAliasOut(MBUF_CTOP(bp), bp->m_len);
486 bp->m_len = ntohs(((struct ip *)MBUF_CTOP(bp))->ip_len);
492 nat_LayerPull(struct bundle *bundle, struct link *l, struct mbuf *bp,
496 int ret, len, nfrags;
500 if (!bundle->NatEnabled || *proto != PROTO_IP)
503 log_Printf(LogDEBUG, "nat_LayerPull: PROTO_IP -> PROTO_IP\n");
504 m_settype(bp, MB_NATIN);
505 /* Ensure there's a bit of extra buffer for the NAT code... */
506 bp = m_pullup(m_append(bp, NULL, NAT_EXTRABUF));
507 ret = PacketAliasIn(MBUF_CTOP(bp), bp->m_len);
509 bp->m_len = ntohs(((struct ip *)MBUF_CTOP(bp))->ip_len);
510 if (bp->m_len > MAX_MRU) {
511 log_Printf(LogWARN, "nat_LayerPull: Problem with IP header length (%lu)\n",
512 (unsigned long)bp->m_len);
521 case PKT_ALIAS_UNRESOLVED_FRAGMENT:
522 /* Save the data for later */
523 fptr = malloc(bp->m_len);
524 bp = mbuf_Read(bp, fptr, bp->m_len);
525 PacketAliasSaveFragment(fptr);
526 log_Printf(LogDEBUG, "Store another frag (%lu) - now %d\n",
527 (unsigned long)((struct ip *)fptr)->ip_id, ++gfrags);
530 case PKT_ALIAS_FOUND_HEADER_FRAGMENT:
531 /* Fetch all the saved fragments and chain them on the end of `bp' */
532 last = &bp->m_nextpkt;
534 while ((fptr = PacketAliasGetFragment(MBUF_CTOP(bp))) != NULL) {
536 PacketAliasFragmentIn(MBUF_CTOP(bp), fptr);
537 len = ntohs(((struct ip *)fptr)->ip_len);
538 *last = m_get(len, MB_NATIN);
539 memcpy(MBUF_CTOP(*last), fptr, len);
541 last = &(*last)->m_nextpkt;
544 log_Printf(LogDEBUG, "Found a frag header (%lu) - plus %d more frags (no"
545 "w %d)\n", (unsigned long)((struct ip *)MBUF_CTOP(bp))->ip_id,
549 case PKT_ALIAS_IGNORED:
550 if (PacketAliasSetMode(0, 0) & PKT_ALIAS_DENY_INCOMING) {
551 log_Printf(LogTCPIP, "NAT engine denied data:\n");
554 } else if (log_IsKept(LogTCPIP)) {
555 log_Printf(LogTCPIP, "NAT engine ignored data:\n");
556 PacketCheck(bundle, AF_INET, MBUF_CTOP(bp), bp->m_len, NULL,
562 log_Printf(LogWARN, "nat_LayerPull: Dropped a packet (%d)....\n", ret);
571 struct layer natlayer =
572 { LAYER_NAT, "nat", nat_LayerPush, nat_LayerPull };