| 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 $ |
| 27 | * $DragonFly: src/sys/netgraph7/ng_nat.c,v 1.2 2008/06/26 23:05:35 dillon Exp $ |
| 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 | |
| 48 | #include "ng_message.h" |
| 49 | #include "ng_parse.h" |
| 50 | #include "ng_nat.h" |
| 51 | #include "netgraph.h" |
| 52 | |
| 53 | static ng_constructor_t ng_nat_constructor; |
| 54 | static ng_rcvmsg_t ng_nat_rcvmsg; |
| 55 | static ng_shutdown_t ng_nat_shutdown; |
| 56 | static ng_newhook_t ng_nat_newhook; |
| 57 | static ng_rcvdata_t ng_nat_rcvdata; |
| 58 | static ng_disconnect_t ng_nat_disconnect; |
| 59 | |
| 60 | static unsigned int ng_nat_translate_flags(unsigned int x); |
| 61 | |
| 62 | /* Parse type for struct ng_nat_mode. */ |
| 63 | static const struct ng_parse_struct_field ng_nat_mode_fields[] |
| 64 | = NG_NAT_MODE_INFO; |
| 65 | static 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. */ |
| 71 | static const struct ng_parse_fixedstring_info ng_nat_description_info |
| 72 | = { NG_NAT_DESC_LENGTH }; |
| 73 | static 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. */ |
| 79 | static const struct ng_parse_struct_field ng_nat_redirect_port_fields[] |
| 80 | = NG_NAT_REDIRECT_PORT_TYPE_INFO(&ng_nat_description_type); |
| 81 | static 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. */ |
| 87 | static const struct ng_parse_struct_field ng_nat_redirect_addr_fields[] |
| 88 | = NG_NAT_REDIRECT_ADDR_TYPE_INFO(&ng_nat_description_type); |
| 89 | static 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. */ |
| 95 | static const struct ng_parse_struct_field ng_nat_redirect_proto_fields[] |
| 96 | = NG_NAT_REDIRECT_PROTO_TYPE_INFO(&ng_nat_description_type); |
| 97 | static 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. */ |
| 103 | static const struct ng_parse_struct_field ng_nat_add_server_fields[] |
| 104 | = NG_NAT_ADD_SERVER_TYPE_INFO; |
| 105 | static 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. */ |
| 111 | static const struct ng_parse_struct_field ng_nat_listrdrs_entry_fields[] |
| 112 | = NG_NAT_LISTRDRS_ENTRY_TYPE_INFO(&ng_nat_description_type); |
| 113 | static 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. */ |
| 119 | static int |
| 120 | ng_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 | |
| 130 | static 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 | }; |
| 135 | static 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. */ |
| 141 | static const struct ng_parse_struct_field ng_nat_list_redirects_fields[] |
| 142 | = NG_NAT_LIST_REDIRECTS_TYPE_INFO(&ng_nat_listrdrs_ary_type); |
| 143 | static 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. */ |
| 149 | static 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. */ |
| 231 | static 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 | }; |
| 242 | NETGRAPH_INIT(nat, &typestruct); |
| 243 | MODULE_DEPEND(ng_nat, libalias, 1, 1, 1); |
| 244 | |
| 245 | /* Element for list of redirects. */ |
| 246 | struct 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 | }; |
| 251 | STAILQ_HEAD(rdrhead, ng_nat_rdr_lst); |
| 252 | |
| 253 | /* Information we store for each node. */ |
| 254 | struct 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 | }; |
| 264 | typedef 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 | |
| 270 | static int |
| 271 | ng_nat_constructor(node_p node) |
| 272 | { |
| 273 | priv_p priv; |
| 274 | |
| 275 | /* Initialize private descriptor. */ |
| 276 | priv = kmalloc(sizeof(*priv), M_NETGRAPH, |
| 277 | M_WAITOK | M_NULLOK | M_ZERO); |
| 278 | if (priv == NULL) |
| 279 | return (ENOMEM); |
| 280 | |
| 281 | /* Init aliasing engine. */ |
| 282 | priv->lib = LibAliasInit(NULL); |
| 283 | if (priv->lib == NULL) { |
| 284 | kfree(priv, M_NETGRAPH); |
| 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 | |
| 310 | static int |
| 311 | ng_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 | |
| 329 | static int |
| 330 | ng_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 | |
| 397 | if ((entry = kmalloc(sizeof(struct ng_nat_rdr_lst), |
| 398 | M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO)) == NULL) { |
| 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; |
| 412 | kfree(entry, M_NETGRAPH); |
| 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. */ |
| 437 | NG_MKRESPONSE(resp, msg, sizeof(entry->rdr.id), M_WAITOK | M_NULLOK); |
| 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 | |
| 456 | if ((entry = kmalloc(sizeof(struct ng_nat_rdr_lst), |
| 457 | M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO)) == NULL) { |
| 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; |
| 468 | kfree(entry, M_NETGRAPH); |
| 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. */ |
| 489 | NG_MKRESPONSE(resp, msg, sizeof(entry->rdr.id), M_WAITOK | M_NULLOK); |
| 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 | |
| 508 | if ((entry = kmalloc(sizeof(struct ng_nat_rdr_lst), |
| 509 | M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO)) == NULL) { |
| 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; |
| 521 | kfree(entry, M_NETGRAPH); |
| 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. */ |
| 543 | NG_MKRESPONSE(resp, msg, sizeof(entry->rdr.id), M_WAITOK | M_NULLOK); |
| 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); |
| 587 | kfree(entry, M_NETGRAPH); |
| 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) + |
| 629 | (priv->rdrcount) * sizeof(*entry), M_WAITOK | M_NULLOK); |
| 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 | |
| 672 | static int |
| 673 | ng_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 | |
| 768 | send: |
| 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 | |
| 777 | static int |
| 778 | ng_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); |
| 789 | kfree(entry, M_NETGRAPH); |
| 790 | }; |
| 791 | |
| 792 | /* Final free. */ |
| 793 | LibAliasUninit(priv->lib); |
| 794 | kfree(priv, M_NETGRAPH); |
| 795 | |
| 796 | return (0); |
| 797 | } |
| 798 | |
| 799 | static int |
| 800 | ng_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 | |
| 817 | static unsigned int |
| 818 | ng_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 | } |