kernel/netgraph7: Replace usage of MALLOC/FREE with kmalloc/kfree here too.
[dragonfly.git] / sys / netgraph7 / ng_nat.c
CommitLineData
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1/*-
2 * Copyright 2005, Gleb Smirnoff <glebius@FreeBSD.org>
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: src/sys/netgraph/ng_nat.c,v 1.12 2008/06/01 15:13:32 mav Exp $
5a975a3d 27 * $DragonFly: src/sys/netgraph7/ng_nat.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
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28 */
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/mbuf.h>
34#include <sys/malloc.h>
35#include <sys/ctype.h>
36#include <sys/errno.h>
37#include <sys/syslog.h>
38
39#include <netinet/in_systm.h>
40#include <netinet/in.h>
41#include <netinet/ip.h>
42#include <netinet/ip_var.h>
43#include <netinet/tcp.h>
44#include <machine/in_cksum.h>
45
46#include <netinet/libalias/alias.h>
47
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48#include "ng_message.h"
49#include "ng_parse.h"
50#include "ng_nat.h"
51#include "netgraph.h"
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52
53static ng_constructor_t ng_nat_constructor;
54static ng_rcvmsg_t ng_nat_rcvmsg;
55static ng_shutdown_t ng_nat_shutdown;
56static ng_newhook_t ng_nat_newhook;
57static ng_rcvdata_t ng_nat_rcvdata;
58static ng_disconnect_t ng_nat_disconnect;
59
60static unsigned int ng_nat_translate_flags(unsigned int x);
61
62/* Parse type for struct ng_nat_mode. */
63static const struct ng_parse_struct_field ng_nat_mode_fields[]
64 = NG_NAT_MODE_INFO;
65static const struct ng_parse_type ng_nat_mode_type = {
66 &ng_parse_struct_type,
67 &ng_nat_mode_fields
68};
69
70/* Parse type for 'description' field in structs. */
71static const struct ng_parse_fixedstring_info ng_nat_description_info
72 = { NG_NAT_DESC_LENGTH };
73static const struct ng_parse_type ng_nat_description_type = {
74 &ng_parse_fixedstring_type,
75 &ng_nat_description_info
76};
77
78/* Parse type for struct ng_nat_redirect_port. */
79static const struct ng_parse_struct_field ng_nat_redirect_port_fields[]
80 = NG_NAT_REDIRECT_PORT_TYPE_INFO(&ng_nat_description_type);
81static const struct ng_parse_type ng_nat_redirect_port_type = {
82 &ng_parse_struct_type,
83 &ng_nat_redirect_port_fields
84};
85
86/* Parse type for struct ng_nat_redirect_addr. */
87static const struct ng_parse_struct_field ng_nat_redirect_addr_fields[]
88 = NG_NAT_REDIRECT_ADDR_TYPE_INFO(&ng_nat_description_type);
89static const struct ng_parse_type ng_nat_redirect_addr_type = {
90 &ng_parse_struct_type,
91 &ng_nat_redirect_addr_fields
92};
93
94/* Parse type for struct ng_nat_redirect_proto. */
95static const struct ng_parse_struct_field ng_nat_redirect_proto_fields[]
96 = NG_NAT_REDIRECT_PROTO_TYPE_INFO(&ng_nat_description_type);
97static const struct ng_parse_type ng_nat_redirect_proto_type = {
98 &ng_parse_struct_type,
99 &ng_nat_redirect_proto_fields
100};
101
102/* Parse type for struct ng_nat_add_server. */
103static const struct ng_parse_struct_field ng_nat_add_server_fields[]
104 = NG_NAT_ADD_SERVER_TYPE_INFO;
105static const struct ng_parse_type ng_nat_add_server_type = {
106 &ng_parse_struct_type,
107 &ng_nat_add_server_fields
108};
109
110/* Parse type for one struct ng_nat_listrdrs_entry. */
111static const struct ng_parse_struct_field ng_nat_listrdrs_entry_fields[]
112 = NG_NAT_LISTRDRS_ENTRY_TYPE_INFO(&ng_nat_description_type);
113static const struct ng_parse_type ng_nat_listrdrs_entry_type = {
114 &ng_parse_struct_type,
115 &ng_nat_listrdrs_entry_fields
116};
117
118/* Parse type for 'redirects' array in struct ng_nat_list_redirects. */
119static int
120ng_nat_listrdrs_ary_getLength(const struct ng_parse_type *type,
121 const u_char *start, const u_char *buf)
122{
123 const struct ng_nat_list_redirects *lr;
124
125 lr = (const struct ng_nat_list_redirects *)
126 (buf - offsetof(struct ng_nat_list_redirects, redirects));
127 return lr->total_count;
128}
129
130static const struct ng_parse_array_info ng_nat_listrdrs_ary_info = {
131 &ng_nat_listrdrs_entry_type,
132 &ng_nat_listrdrs_ary_getLength,
133 NULL
134};
135static const struct ng_parse_type ng_nat_listrdrs_ary_type = {
136 &ng_parse_array_type,
137 &ng_nat_listrdrs_ary_info
138};
139
140/* Parse type for struct ng_nat_list_redirects. */
141static const struct ng_parse_struct_field ng_nat_list_redirects_fields[]
142 = NG_NAT_LIST_REDIRECTS_TYPE_INFO(&ng_nat_listrdrs_ary_type);
143static const struct ng_parse_type ng_nat_list_redirects_type = {
144 &ng_parse_struct_type,
145 &ng_nat_list_redirects_fields
146};
147
148/* List of commands and how to convert arguments to/from ASCII. */
149static const struct ng_cmdlist ng_nat_cmdlist[] = {
150 {
151 NGM_NAT_COOKIE,
152 NGM_NAT_SET_IPADDR,
153 "setaliasaddr",
154 &ng_parse_ipaddr_type,
155 NULL
156 },
157 {
158 NGM_NAT_COOKIE,
159 NGM_NAT_SET_MODE,
160 "setmode",
161 &ng_nat_mode_type,
162 NULL
163 },
164 {
165 NGM_NAT_COOKIE,
166 NGM_NAT_SET_TARGET,
167 "settarget",
168 &ng_parse_ipaddr_type,
169 NULL
170 },
171 {
172 NGM_NAT_COOKIE,
173 NGM_NAT_REDIRECT_PORT,
174 "redirectport",
175 &ng_nat_redirect_port_type,
176 &ng_parse_uint32_type
177 },
178 {
179 NGM_NAT_COOKIE,
180 NGM_NAT_REDIRECT_ADDR,
181 "redirectaddr",
182 &ng_nat_redirect_addr_type,
183 &ng_parse_uint32_type
184 },
185 {
186 NGM_NAT_COOKIE,
187 NGM_NAT_REDIRECT_PROTO,
188 "redirectproto",
189 &ng_nat_redirect_proto_type,
190 &ng_parse_uint32_type
191 },
192 {
193 NGM_NAT_COOKIE,
194 NGM_NAT_REDIRECT_DYNAMIC,
195 "redirectdynamic",
196 &ng_parse_uint32_type,
197 NULL
198 },
199 {
200 NGM_NAT_COOKIE,
201 NGM_NAT_REDIRECT_DELETE,
202 "redirectdelete",
203 &ng_parse_uint32_type,
204 NULL
205 },
206 {
207 NGM_NAT_COOKIE,
208 NGM_NAT_ADD_SERVER,
209 "addserver",
210 &ng_nat_add_server_type,
211 NULL
212 },
213 {
214 NGM_NAT_COOKIE,
215 NGM_NAT_LIST_REDIRECTS,
216 "listredirects",
217 NULL,
218 &ng_nat_list_redirects_type
219 },
220 {
221 NGM_NAT_COOKIE,
222 NGM_NAT_PROXY_RULE,
223 "proxyrule",
224 &ng_parse_string_type,
225 NULL
226 },
227 { 0 }
228};
229
230/* Netgraph node type descriptor. */
231static struct ng_type typestruct = {
232 .version = NG_ABI_VERSION,
233 .name = NG_NAT_NODE_TYPE,
234 .constructor = ng_nat_constructor,
235 .rcvmsg = ng_nat_rcvmsg,
236 .shutdown = ng_nat_shutdown,
237 .newhook = ng_nat_newhook,
238 .rcvdata = ng_nat_rcvdata,
239 .disconnect = ng_nat_disconnect,
240 .cmdlist = ng_nat_cmdlist,
241};
242NETGRAPH_INIT(nat, &typestruct);
243MODULE_DEPEND(ng_nat, libalias, 1, 1, 1);
244
245/* Element for list of redirects. */
246struct ng_nat_rdr_lst {
247 STAILQ_ENTRY(ng_nat_rdr_lst) entries;
248 struct alias_link *lnk;
249 struct ng_nat_listrdrs_entry rdr;
250};
251STAILQ_HEAD(rdrhead, ng_nat_rdr_lst);
252
253/* Information we store for each node. */
254struct ng_nat_priv {
255 node_p node; /* back pointer to node */
256 hook_p in; /* hook for demasquerading */
257 hook_p out; /* hook for masquerading */
258 struct libalias *lib; /* libalias handler */
259 uint32_t flags; /* status flags */
260 uint32_t rdrcount; /* number or redirects in list */
261 uint32_t nextid; /* for next in turn in list */
262 struct rdrhead redirhead; /* redirect list header */
263};
264typedef struct ng_nat_priv *priv_p;
265
266/* Values of flags */
267#define NGNAT_CONNECTED 0x1 /* We have both hooks connected */
268#define NGNAT_ADDR_DEFINED 0x2 /* NGM_NAT_SET_IPADDR happened */
269
270static int
271ng_nat_constructor(node_p node)
272{
273 priv_p priv;
274
275 /* Initialize private descriptor. */
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276 priv = kmalloc(sizeof(*priv), M_NETGRAPH,
277 M_WAITOK | M_NULLOK | M_ZERO);
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278 if (priv == NULL)
279 return (ENOMEM);
280
281 /* Init aliasing engine. */
282 priv->lib = LibAliasInit(NULL);
283 if (priv->lib == NULL) {
fc025606 284 kfree(priv, M_NETGRAPH);
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285 return (ENOMEM);
286 }
287
288 /* Set same ports on. */
289 (void )LibAliasSetMode(priv->lib, PKT_ALIAS_SAME_PORTS,
290 PKT_ALIAS_SAME_PORTS);
291
292 /* Init redirects housekeeping. */
293 priv->rdrcount = 0;
294 priv->nextid = 1;
295 STAILQ_INIT(&priv->redirhead);
296
297 /* Link structs together. */
298 NG_NODE_SET_PRIVATE(node, priv);
299 priv->node = node;
300
301 /*
302 * libalias is not thread safe, so our node
303 * must be single threaded.
304 */
305 NG_NODE_FORCE_WRITER(node);
306
307 return (0);
308}
309
310static int
311ng_nat_newhook(node_p node, hook_p hook, const char *name)
312{
313 const priv_p priv = NG_NODE_PRIVATE(node);
314
315 if (strcmp(name, NG_NAT_HOOK_IN) == 0) {
316 priv->in = hook;
317 } else if (strcmp(name, NG_NAT_HOOK_OUT) == 0) {
318 priv->out = hook;
319 } else
320 return (EINVAL);
321
322 if (priv->out != NULL &&
323 priv->in != NULL)
324 priv->flags |= NGNAT_CONNECTED;
325
326 return(0);
327}
328
329static int
330ng_nat_rcvmsg(node_p node, item_p item, hook_p lasthook)
331{
332 const priv_p priv = NG_NODE_PRIVATE(node);
333 struct ng_mesg *resp = NULL;
334 struct ng_mesg *msg;
335 int error = 0;
336
337 NGI_GET_MSG(item, msg);
338
339 switch (msg->header.typecookie) {
340 case NGM_NAT_COOKIE:
341 switch (msg->header.cmd) {
342 case NGM_NAT_SET_IPADDR:
343 {
344 struct in_addr *const ia = (struct in_addr *)msg->data;
345
346 if (msg->header.arglen < sizeof(*ia)) {
347 error = EINVAL;
348 break;
349 }
350
351 LibAliasSetAddress(priv->lib, *ia);
352
353 priv->flags |= NGNAT_ADDR_DEFINED;
354 }
355 break;
356 case NGM_NAT_SET_MODE:
357 {
358 struct ng_nat_mode *const mode =
359 (struct ng_nat_mode *)msg->data;
360
361 if (msg->header.arglen < sizeof(*mode)) {
362 error = EINVAL;
363 break;
364 }
365
366 if (LibAliasSetMode(priv->lib,
367 ng_nat_translate_flags(mode->flags),
368 ng_nat_translate_flags(mode->mask)) < 0) {
369 error = ENOMEM;
370 break;
371 }
372 }
373 break;
374 case NGM_NAT_SET_TARGET:
375 {
376 struct in_addr *const ia = (struct in_addr *)msg->data;
377
378 if (msg->header.arglen < sizeof(*ia)) {
379 error = EINVAL;
380 break;
381 }
382
383 LibAliasSetTarget(priv->lib, *ia);
384 }
385 break;
386 case NGM_NAT_REDIRECT_PORT:
387 {
388 struct ng_nat_rdr_lst *entry;
389 struct ng_nat_redirect_port *const rp =
390 (struct ng_nat_redirect_port *)msg->data;
391
392 if (msg->header.arglen < sizeof(*rp)) {
393 error = EINVAL;
394 break;
395 }
396
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397 if ((entry = kmalloc(sizeof(struct ng_nat_rdr_lst),
398 M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO)) == NULL) {
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399 error = ENOMEM;
400 break;
401 }
402
403 /* Try actual redirect. */
404 entry->lnk = LibAliasRedirectPort(priv->lib,
405 rp->local_addr, htons(rp->local_port),
406 rp->remote_addr, htons(rp->remote_port),
407 rp->alias_addr, htons(rp->alias_port),
408 rp->proto);
409
410 if (entry->lnk == NULL) {
411 error = ENOMEM;
fc025606 412 kfree(entry, M_NETGRAPH);
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413 break;
414 }
415
416 /* Successful, save info in our internal list. */
417 entry->rdr.local_addr = rp->local_addr;
418 entry->rdr.alias_addr = rp->alias_addr;
419 entry->rdr.remote_addr = rp->remote_addr;
420 entry->rdr.local_port = rp->local_port;
421 entry->rdr.alias_port = rp->alias_port;
422 entry->rdr.remote_port = rp->remote_port;
423 entry->rdr.proto = rp->proto;
424 bcopy(rp->description, entry->rdr.description,
425 NG_NAT_DESC_LENGTH);
426
427 /* Safety precaution. */
428 entry->rdr.description[NG_NAT_DESC_LENGTH-1] = '\0';
429
430 entry->rdr.id = priv->nextid++;
431 priv->rdrcount++;
432
433 /* Link to list of redirects. */
434 STAILQ_INSERT_TAIL(&priv->redirhead, entry, entries);
435
436 /* Response with id of newly added entry. */
5a975a3d 437 NG_MKRESPONSE(resp, msg, sizeof(entry->rdr.id), M_WAITOK | M_NULLOK);
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438 if (resp == NULL) {
439 error = ENOMEM;
440 break;
441 }
442 bcopy(&entry->rdr.id, resp->data, sizeof(entry->rdr.id));
443 }
444 break;
445 case NGM_NAT_REDIRECT_ADDR:
446 {
447 struct ng_nat_rdr_lst *entry;
448 struct ng_nat_redirect_addr *const ra =
449 (struct ng_nat_redirect_addr *)msg->data;
450
451 if (msg->header.arglen < sizeof(*ra)) {
452 error = EINVAL;
453 break;
454 }
455
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456 if ((entry = kmalloc(sizeof(struct ng_nat_rdr_lst),
457 M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO)) == NULL) {
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458 error = ENOMEM;
459 break;
460 }
461
462 /* Try actual redirect. */
463 entry->lnk = LibAliasRedirectAddr(priv->lib,
464 ra->local_addr, ra->alias_addr);
465
466 if (entry->lnk == NULL) {
467 error = ENOMEM;
fc025606 468 kfree(entry, M_NETGRAPH);
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469 break;
470 }
471
472 /* Successful, save info in our internal list. */
473 entry->rdr.local_addr = ra->local_addr;
474 entry->rdr.alias_addr = ra->alias_addr;
475 entry->rdr.proto = NG_NAT_REDIRPROTO_ADDR;
476 bcopy(ra->description, entry->rdr.description,
477 NG_NAT_DESC_LENGTH);
478
479 /* Safety precaution. */
480 entry->rdr.description[NG_NAT_DESC_LENGTH-1] = '\0';
481
482 entry->rdr.id = priv->nextid++;
483 priv->rdrcount++;
484
485 /* Link to list of redirects. */
486 STAILQ_INSERT_TAIL(&priv->redirhead, entry, entries);
487
488 /* Response with id of newly added entry. */
5a975a3d 489 NG_MKRESPONSE(resp, msg, sizeof(entry->rdr.id), M_WAITOK | M_NULLOK);
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490 if (resp == NULL) {
491 error = ENOMEM;
492 break;
493 }
494 bcopy(&entry->rdr.id, resp->data, sizeof(entry->rdr.id));
495 }
496 break;
497 case NGM_NAT_REDIRECT_PROTO:
498 {
499 struct ng_nat_rdr_lst *entry;
500 struct ng_nat_redirect_proto *const rp =
501 (struct ng_nat_redirect_proto *)msg->data;
502
503 if (msg->header.arglen < sizeof(*rp)) {
504 error = EINVAL;
505 break;
506 }
507
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508 if ((entry = kmalloc(sizeof(struct ng_nat_rdr_lst),
509 M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO)) == NULL) {
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510 error = ENOMEM;
511 break;
512 }
513
514 /* Try actual redirect. */
515 entry->lnk = LibAliasRedirectProto(priv->lib,
516 rp->local_addr, rp->remote_addr,
517 rp->alias_addr, rp->proto);
518
519 if (entry->lnk == NULL) {
520 error = ENOMEM;
fc025606 521 kfree(entry, M_NETGRAPH);
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522 break;
523 }
524
525 /* Successful, save info in our internal list. */
526 entry->rdr.local_addr = rp->local_addr;
527 entry->rdr.alias_addr = rp->alias_addr;
528 entry->rdr.remote_addr = rp->remote_addr;
529 entry->rdr.proto = rp->proto;
530 bcopy(rp->description, entry->rdr.description,
531 NG_NAT_DESC_LENGTH);
532
533 /* Safety precaution. */
534 entry->rdr.description[NG_NAT_DESC_LENGTH-1] = '\0';
535
536 entry->rdr.id = priv->nextid++;
537 priv->rdrcount++;
538
539 /* Link to list of redirects. */
540 STAILQ_INSERT_TAIL(&priv->redirhead, entry, entries);
541
542 /* Response with id of newly added entry. */
5a975a3d 543 NG_MKRESPONSE(resp, msg, sizeof(entry->rdr.id), M_WAITOK | M_NULLOK);
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544 if (resp == NULL) {
545 error = ENOMEM;
546 break;
547 }
548 bcopy(&entry->rdr.id, resp->data, sizeof(entry->rdr.id));
549 }
550 break;
551 case NGM_NAT_REDIRECT_DYNAMIC:
552 case NGM_NAT_REDIRECT_DELETE:
553 {
554 struct ng_nat_rdr_lst *entry;
555 uint32_t *const id = (uint32_t *)msg->data;
556
557 if (msg->header.arglen < sizeof(*id)) {
558 error = EINVAL;
559 break;
560 }
561
562 /* Find entry with supplied id. */
563 STAILQ_FOREACH(entry, &priv->redirhead, entries) {
564 if (entry->rdr.id == *id)
565 break;
566 }
567
568 /* Not found. */
569 if (entry == NULL) {
570 error = ENOENT;
571 break;
572 }
573
574 if (msg->header.cmd == NGM_NAT_REDIRECT_DYNAMIC) {
575 if (LibAliasRedirectDynamic(priv->lib,
576 entry->lnk) == -1) {
577 error = ENOTTY; /* XXX Something better? */
578 break;
579 }
580 } else { /* NGM_NAT_REDIRECT_DELETE */
581 LibAliasRedirectDelete(priv->lib, entry->lnk);
582 }
583
584 /* Delete entry from our internal list. */
585 priv->rdrcount--;
586 STAILQ_REMOVE(&priv->redirhead, entry, ng_nat_rdr_lst, entries);
fc025606 587 kfree(entry, M_NETGRAPH);
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588 }
589 break;
590 case NGM_NAT_ADD_SERVER:
591 {
592 struct ng_nat_rdr_lst *entry;
593 struct ng_nat_add_server *const as =
594 (struct ng_nat_add_server *)msg->data;
595
596 if (msg->header.arglen < sizeof(*as)) {
597 error = EINVAL;
598 break;
599 }
600
601 /* Find entry with supplied id. */
602 STAILQ_FOREACH(entry, &priv->redirhead, entries) {
603 if (entry->rdr.id == as->id)
604 break;
605 }
606
607 /* Not found. */
608 if (entry == NULL) {
609 error = ENOENT;
610 break;
611 }
612
613 if (LibAliasAddServer(priv->lib, entry->lnk,
614 as->addr, htons(as->port)) == -1) {
615 error = ENOMEM;
616 break;
617 }
618
619 entry->rdr.lsnat++;
620 }
621 break;
622 case NGM_NAT_LIST_REDIRECTS:
623 {
624 struct ng_nat_rdr_lst *entry;
625 struct ng_nat_list_redirects *ary;
626 int i = 0;
627
628 NG_MKRESPONSE(resp, msg, sizeof(*ary) +
5a975a3d 629 (priv->rdrcount) * sizeof(*entry), M_WAITOK | M_NULLOK);
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630 if (resp == NULL) {
631 error = ENOMEM;
632 break;
633 }
634
635 ary = (struct ng_nat_list_redirects *)resp->data;
636 ary->total_count = priv->rdrcount;
637
638 STAILQ_FOREACH(entry, &priv->redirhead, entries) {
639 bcopy(&entry->rdr, &ary->redirects[i++],
640 sizeof(struct ng_nat_listrdrs_entry));
641 }
642 }
643 break;
644 case NGM_NAT_PROXY_RULE:
645 {
646 char *cmd = (char *)msg->data;
647
648 if (msg->header.arglen < 6) {
649 error = EINVAL;
650 break;
651 }
652
653 if (LibAliasProxyRule(priv->lib, cmd) != 0)
654 error = ENOMEM;
655 }
656 break;
657 default:
658 error = EINVAL; /* unknown command */
659 break;
660 }
661 break;
662 default:
663 error = EINVAL; /* unknown cookie type */
664 break;
665 }
666
667 NG_RESPOND_MSG(error, node, item, resp);
668 NG_FREE_MSG(msg);
669 return (error);
670}
671
672static int
673ng_nat_rcvdata(hook_p hook, item_p item )
674{
675 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
676 struct mbuf *m;
677 struct ip *ip;
678 int rval, error = 0;
679 char *c;
680
681 /* We have no required hooks. */
682 if (!(priv->flags & NGNAT_CONNECTED)) {
683 NG_FREE_ITEM(item);
684 return (ENXIO);
685 }
686
687 /* We have no alias address yet to do anything. */
688 if (!(priv->flags & NGNAT_ADDR_DEFINED))
689 goto send;
690
691 m = NGI_M(item);
692
693 if ((m = m_megapullup(m, m->m_pkthdr.len)) == NULL) {
694 NGI_M(item) = NULL; /* avoid double free */
695 NG_FREE_ITEM(item);
696 return (ENOBUFS);
697 }
698
699 NGI_M(item) = m;
700
701 c = mtod(m, char *);
702 ip = mtod(m, struct ip *);
703
704 KASSERT(m->m_pkthdr.len == ntohs(ip->ip_len),
705 ("ng_nat: ip_len != m_pkthdr.len"));
706
707 if (hook == priv->in) {
708 rval = LibAliasIn(priv->lib, c, m->m_len + M_TRAILINGSPACE(m));
709 if (rval != PKT_ALIAS_OK &&
710 rval != PKT_ALIAS_FOUND_HEADER_FRAGMENT) {
711 NG_FREE_ITEM(item);
712 return (EINVAL);
713 }
714 } else if (hook == priv->out) {
715 rval = LibAliasOut(priv->lib, c, m->m_len + M_TRAILINGSPACE(m));
716 if (rval != PKT_ALIAS_OK) {
717 NG_FREE_ITEM(item);
718 return (EINVAL);
719 }
720 } else
721 panic("ng_nat: unknown hook!\n");
722
723 m->m_pkthdr.len = m->m_len = ntohs(ip->ip_len);
724
725 if ((ip->ip_off & htons(IP_OFFMASK)) == 0 &&
726 ip->ip_p == IPPROTO_TCP) {
727 struct tcphdr *th = (struct tcphdr *)((caddr_t)ip +
728 (ip->ip_hl << 2));
729
730 /*
731 * Here is our terrible HACK.
732 *
733 * Sometimes LibAlias edits contents of TCP packet.
734 * In this case it needs to recompute full TCP
735 * checksum. However, the problem is that LibAlias
736 * doesn't have any idea about checksum offloading
737 * in kernel. To workaround this, we do not do
738 * checksumming in LibAlias, but only mark the
739 * packets in th_x2 field. If we receive a marked
740 * packet, we calculate correct checksum for it
741 * aware of offloading.
742 *
743 * Why do I do such a terrible hack instead of
744 * recalculating checksum for each packet?
745 * Because the previous checksum was not checked!
746 * Recalculating checksums for EVERY packet will
747 * hide ALL transmission errors. Yes, marked packets
748 * still suffer from this problem. But, sigh, natd(8)
749 * has this problem, too.
750 */
751
752 if (th->th_x2) {
753 th->th_x2 = 0;
754 ip->ip_len = ntohs(ip->ip_len);
755 th->th_sum = in_pseudo(ip->ip_src.s_addr,
756 ip->ip_dst.s_addr, htons(IPPROTO_TCP +
757 ip->ip_len - (ip->ip_hl << 2)));
758
759 if ((m->m_pkthdr.csum_flags & CSUM_TCP) == 0) {
760 m->m_pkthdr.csum_data = offsetof(struct tcphdr,
761 th_sum);
762 in_delayed_cksum(m);
763 }
764 ip->ip_len = htons(ip->ip_len);
765 }
766 }
767
768send:
769 if (hook == priv->in)
770 NG_FWD_ITEM_HOOK(error, item, priv->out);
771 else
772 NG_FWD_ITEM_HOOK(error, item, priv->in);
773
774 return (error);
775}
776
777static int
778ng_nat_shutdown(node_p node)
779{
780 const priv_p priv = NG_NODE_PRIVATE(node);
781
782 NG_NODE_SET_PRIVATE(node, NULL);
783 NG_NODE_UNREF(node);
784
785 /* Free redirects list. */
786 while (!STAILQ_EMPTY(&priv->redirhead)) {
787 struct ng_nat_rdr_lst *entry = STAILQ_FIRST(&priv->redirhead);
788 STAILQ_REMOVE_HEAD(&priv->redirhead, entries);
fc025606 789 kfree(entry, M_NETGRAPH);
b06ebda0
MD
790 };
791
792 /* Final free. */
793 LibAliasUninit(priv->lib);
fc025606 794 kfree(priv, M_NETGRAPH);
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795
796 return (0);
797}
798
799static int
800ng_nat_disconnect(hook_p hook)
801{
802 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
803
804 priv->flags &= ~NGNAT_CONNECTED;
805
806 if (hook == priv->out)
807 priv->out = NULL;
808 if (hook == priv->in)
809 priv->in = NULL;
810
811 if (priv->out == NULL && priv->in == NULL)
812 ng_rmnode_self(NG_HOOK_NODE(hook));
813
814 return (0);
815}
816
817static unsigned int
818ng_nat_translate_flags(unsigned int x)
819{
820 unsigned int res = 0;
821
822 if (x & NG_NAT_LOG)
823 res |= PKT_ALIAS_LOG;
824 if (x & NG_NAT_DENY_INCOMING)
825 res |= PKT_ALIAS_DENY_INCOMING;
826 if (x & NG_NAT_SAME_PORTS)
827 res |= PKT_ALIAS_SAME_PORTS;
828 if (x & NG_NAT_UNREGISTERED_ONLY)
829 res |= PKT_ALIAS_UNREGISTERED_ONLY;
830 if (x & NG_NAT_RESET_ON_ADDR_CHANGE)
831 res |= PKT_ALIAS_RESET_ON_ADDR_CHANGE;
832 if (x & NG_NAT_PROXY_ONLY)
833 res |= PKT_ALIAS_PROXY_ONLY;
834 if (x & NG_NAT_REVERSE)
835 res |= PKT_ALIAS_REVERSE;
836
837 return (res);
838}