1 /* 2 * Copyright (c) 1982, 1986, 1988, 1993 3 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: src/sys/netinet/ip_divert.c,v 1.42.2.6 2003/01/23 21:06:45 sam Exp $ 30 */ 31 32 #define _IP_VHL 33 34 #include "opt_inet.h" 35 #include "opt_ipdivert.h" 36 #include "opt_ipsec.h" 37 38 #ifndef INET 39 #error "IPDIVERT requires INET." 40 #endif 41 42 #include <sys/param.h> 43 #include <sys/kernel.h> 44 #include <sys/malloc.h> 45 #include <sys/mbuf.h> 46 #include <sys/socket.h> 47 #include <sys/protosw.h> 48 #include <sys/socketvar.h> 49 #include <sys/socketvar2.h> 50 #include <sys/sysctl.h> 51 #include <sys/systm.h> 52 #include <sys/proc.h> 53 #include <sys/priv.h> 54 #include <sys/in_cksum.h> 55 #include <sys/lock.h> 56 #include <sys/msgport.h> 57 58 #include <net/if.h> 59 #include <net/route.h> 60 61 #include <net/netmsg2.h> 62 #include <net/netisr2.h> 63 #include <sys/thread2.h> 64 #include <sys/mplock2.h> 65 66 #include <netinet/in.h> 67 #include <netinet/in_systm.h> 68 #include <netinet/ip.h> 69 #include <netinet/in_pcb.h> 70 #include <netinet/in_var.h> 71 #include <netinet/ip_var.h> 72 #include <netinet/ip_divert.h> 73 74 /* 75 * Divert sockets 76 */ 77 78 /* 79 * Allocate enough space to hold a full IP packet 80 */ 81 #define DIVSNDQ (65536 + 100) 82 #define DIVRCVQ (65536 + 100) 83 84 #define DIV_IS_OUTPUT(sin) ((sin) == NULL || (sin)->sin_addr.s_addr == 0) 85 86 #define DIV_OUTPUT 0x10000 87 #define DIV_INPUT 0x20000 88 89 /* 90 * Divert sockets work in conjunction with ipfw, see the divert(4) 91 * manpage for features. 92 * Internally, packets selected by ipfw in ip_input() or ip_output(), 93 * and never diverted before, are passed to the input queue of the 94 * divert socket with a given 'divert_port' number (as specified in 95 * the matching ipfw rule), and they are tagged with a 16 bit cookie 96 * (representing the rule number of the matching ipfw rule), which 97 * is passed to process reading from the socket. 98 * 99 * Packets written to the divert socket are again tagged with a cookie 100 * (usually the same as above) and a destination address. 101 * If the destination address is INADDR_ANY then the packet is 102 * treated as outgoing and sent to ip_output(), otherwise it is 103 * treated as incoming and sent to ip_input(). 104 * In both cases, the packet is tagged with the cookie. 105 * 106 * On reinjection, processing in ip_input() and ip_output() 107 * will be exactly the same as for the original packet, except that 108 * ipfw processing will start at the rule number after the one 109 * written in the cookie (so, tagging a packet with a cookie of 0 110 * will cause it to be effectively considered as a standard packet). 111 */ 112 113 /* Internal variables */ 114 static struct inpcbinfo divcbinfo; 115 static struct inpcbportinfo divcbportinfo; 116 117 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ 118 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ 119 120 static struct mbuf *ip_divert(struct mbuf *, int, int); 121 122 /* 123 * Initialize divert connection block queue. 124 */ 125 void 126 div_init(void) 127 { 128 in_pcbinfo_init(&divcbinfo, 0, FALSE); 129 in_pcbportinfo_init(&divcbportinfo, 1, FALSE, 0); 130 /* 131 * XXX We don't use the hash list for divert IP, but it's easier 132 * to allocate a one entry hash list than it is to check all 133 * over the place for hashbase == NULL. 134 */ 135 divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask); 136 divcbinfo.portinfo = &divcbportinfo; 137 divcbinfo.wildcardhashbase = hashinit(1, M_PCB, 138 &divcbinfo.wildcardhashmask); 139 divcbinfo.ipi_size = sizeof(struct inpcb); 140 ip_divert_p = ip_divert; 141 } 142 143 /* 144 * IPPROTO_DIVERT is not a real IP protocol; don't allow any packets 145 * with that protocol number to enter the system from the outside. 146 */ 147 int 148 div_input(struct mbuf **mp, int *offp, int proto) 149 { 150 struct mbuf *m = *mp; 151 152 ipstat.ips_noproto++; 153 m_freem(m); 154 return(IPPROTO_DONE); 155 } 156 157 /* 158 * Divert a packet by passing it up to the divert socket at port 'port'. 159 * 160 * Setup generic address and protocol structures for div_input routine, 161 * then pass them along with mbuf chain. 162 */ 163 static void 164 div_packet(struct mbuf *m, int incoming, int port) 165 { 166 struct sockaddr_in divsrc = { sizeof divsrc, AF_INET }; 167 struct inpcb *inp; 168 struct socket *sa; 169 struct m_tag *mtag; 170 struct divert_info *divinfo; 171 u_int16_t nport; 172 173 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 174 ("not in netisr0")); 175 176 /* Locate the divert info */ 177 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL); 178 divinfo = m_tag_data(mtag); 179 divsrc.sin_port = divinfo->skipto; 180 181 /* 182 * Record receive interface address, if any. 183 * But only for incoming packets. 184 */ 185 divsrc.sin_addr.s_addr = 0; 186 if (incoming) { 187 struct ifaddr_container *ifac; 188 189 /* Find IP address for receive interface */ 190 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid], 191 ifa_link) { 192 struct ifaddr *ifa = ifac->ifa; 193 194 if (ifa->ifa_addr == NULL) 195 continue; 196 if (ifa->ifa_addr->sa_family != AF_INET) 197 continue; 198 divsrc.sin_addr = 199 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; 200 break; 201 } 202 } 203 /* 204 * Record the incoming interface name whenever we have one. 205 */ 206 if (m->m_pkthdr.rcvif) { 207 /* 208 * Hide the actual interface name in there in the 209 * sin_zero array. XXX This needs to be moved to a 210 * different sockaddr type for divert, e.g. 211 * sockaddr_div with multiple fields like 212 * sockaddr_dl. Presently we have only 7 bytes 213 * but that will do for now as most interfaces 214 * are 4 or less + 2 or less bytes for unit. 215 * There is probably a faster way of doing this, 216 * possibly taking it from the sockaddr_dl on the iface. 217 * This solves the problem of a P2P link and a LAN interface 218 * having the same address, which can result in the wrong 219 * interface being assigned to the packet when fed back 220 * into the divert socket. Theoretically if the daemon saves 221 * and re-uses the sockaddr_in as suggested in the man pages, 222 * this iface name will come along for the ride. 223 * (see div_output for the other half of this.) 224 */ 225 ksnprintf(divsrc.sin_zero, sizeof divsrc.sin_zero, "%s", 226 m->m_pkthdr.rcvif->if_xname); 227 } 228 229 /* Put packet on socket queue, if any */ 230 sa = NULL; 231 nport = htons((u_int16_t)port); 232 233 /* 234 * Following loop to locate the inpcb is MPSAFE since the inpcb 235 * insertion/removal happens on the same CPU (CPU0). 236 */ 237 LIST_FOREACH(inp, &divcbinfo.pcblisthead, inp_list) { 238 if (inp->inp_flags & INP_PLACEMARKER) 239 continue; 240 if (inp->inp_lport == nport) 241 sa = inp->inp_socket; 242 } 243 if (sa) { 244 lwkt_gettoken(&sa->so_rcv.ssb_token); 245 if (ssb_appendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc, m, NULL) == 0) 246 m_freem(m); 247 else 248 sorwakeup(sa); 249 lwkt_reltoken(&sa->so_rcv.ssb_token); 250 } else { 251 m_freem(m); 252 ipstat.ips_noproto++; 253 ipstat.ips_delivered--; 254 } 255 } 256 257 static void 258 div_packet_handler(netmsg_t msg) 259 { 260 struct mbuf *m; 261 int port, incoming = 0; 262 263 m = msg->packet.nm_packet; 264 265 port = msg->lmsg.u.ms_result32 & 0xffff; 266 if (msg->lmsg.u.ms_result32 & DIV_INPUT) 267 incoming = 1; 268 div_packet(m, incoming, port); 269 /* no reply, msg embedded in mbuf */ 270 } 271 272 static void 273 divert_packet(struct mbuf *m, int incoming) 274 { 275 struct m_tag *mtag; 276 struct divert_info *divinfo; 277 int port; 278 279 M_ASSERTPKTHDR(m); 280 281 /* Assure header */ 282 if (m->m_len < sizeof(struct ip) && 283 (m = m_pullup(m, sizeof(struct ip))) == NULL) 284 return; 285 286 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL); 287 KASSERT(mtag != NULL, ("%s no divert tag!", __func__)); 288 divinfo = m_tag_data(mtag); 289 290 port = divinfo->port; 291 KASSERT(port != 0, ("%s: port=0", __func__)); 292 293 if (mycpuid != 0) { 294 struct netmsg_packet *nmp; 295 296 nmp = &m->m_hdr.mh_netmsg; 297 netmsg_init(&nmp->base, NULL, &netisr_apanic_rport, 298 0, div_packet_handler); 299 nmp->nm_packet = m; 300 301 nmp->base.lmsg.u.ms_result32 = port; /* port is 16bits */ 302 if (incoming) 303 nmp->base.lmsg.u.ms_result32 |= DIV_INPUT; 304 else 305 nmp->base.lmsg.u.ms_result32 |= DIV_OUTPUT; 306 307 lwkt_sendmsg(netisr_cpuport(0), &nmp->base.lmsg); 308 } else { 309 div_packet(m, incoming, port); 310 } 311 } 312 313 /* 314 * Deliver packet back into the IP processing machinery. 315 * 316 * If no address specified, or address is 0.0.0.0, send to ip_output(); 317 * otherwise, send to ip_input() and mark as having been received on 318 * the interface with that address. 319 */ 320 static int 321 div_output(struct socket *so, struct mbuf *m, 322 struct sockaddr_in *sin, struct mbuf *control) 323 { 324 int error = 0; 325 struct m_tag *mtag; 326 struct divert_info *divinfo; 327 328 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 329 ("not in netisr0")); 330 331 if (control) 332 m_freem(control); /* XXX */ 333 334 /* 335 * Prepare the tag for divert info. Note that a packet 336 * with a 0 tag in mh_data is effectively untagged, 337 * so we could optimize that case. 338 */ 339 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT, sizeof(*divinfo), MB_DONTWAIT); 340 if (mtag == NULL) { 341 error = ENOBUFS; 342 goto cantsend; 343 } 344 m_tag_prepend(m, mtag); 345 346 /* Loopback avoidance and state recovery */ 347 divinfo = m_tag_data(mtag); 348 if (sin) 349 divinfo->skipto = sin->sin_port; 350 else 351 divinfo->skipto = 0; 352 353 /* Reinject packet into the system as incoming or outgoing */ 354 if (DIV_IS_OUTPUT(sin)) { 355 struct ip *const ip = mtod(m, struct ip *); 356 357 /* Don't allow packet length sizes that will crash */ 358 if ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len) { 359 error = EINVAL; 360 goto cantsend; 361 } 362 363 /* Convert fields to host order for ip_output() */ 364 ip->ip_len = ntohs(ip->ip_len); 365 ip->ip_off = ntohs(ip->ip_off); 366 367 /* Send packet to output processing */ 368 ipstat.ips_rawout++; /* XXX */ 369 error = ip_output(m, NULL, NULL, 370 (so->so_options & SO_DONTROUTE) | 371 IP_ALLOWBROADCAST | IP_RAWOUTPUT, 372 NULL, NULL); 373 } else { 374 ip_input(m); 375 } 376 return error; 377 378 cantsend: 379 m_freem(m); 380 return error; 381 } 382 383 static void 384 div_attach(netmsg_t msg) 385 { 386 struct socket *so = msg->attach.base.nm_so; 387 int proto = msg->attach.nm_proto; 388 struct pru_attach_info *ai = msg->attach.nm_ai; 389 struct inpcb *inp; 390 int error; 391 392 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 393 ("not in netisr0")); 394 395 inp = so->so_pcb; 396 if (inp) 397 panic("div_attach"); 398 error = priv_check_cred(ai->p_ucred, PRIV_ROOT, NULL_CRED_OKAY); 399 if (error) 400 goto out; 401 402 error = soreserve(so, div_sendspace, div_recvspace, ai->sb_rlimit); 403 if (error) 404 goto out; 405 error = in_pcballoc(so, &divcbinfo); 406 if (error) 407 goto out; 408 inp = (struct inpcb *)so->so_pcb; 409 inp->inp_ip_p = proto; 410 inp->inp_vflag |= INP_IPV4; 411 inp->inp_flags |= INP_HDRINCL; 412 /* 413 * The socket is always "connected" because 414 * we always know "where" to send the packet. 415 */ 416 sosetstate(so, SS_ISCONNECTED); 417 error = 0; 418 out: 419 lwkt_replymsg(&msg->attach.base.lmsg, error); 420 } 421 422 static void 423 div_detach(netmsg_t msg) 424 { 425 struct socket *so = msg->detach.base.nm_so; 426 struct inpcb *inp; 427 428 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 429 ("not in netisr0")); 430 431 inp = so->so_pcb; 432 if (inp == NULL) 433 panic("div_detach"); 434 in_pcbdetach(inp); 435 lwkt_replymsg(&msg->detach.base.lmsg, 0); 436 } 437 438 static void 439 div_abort(netmsg_t msg) 440 { 441 /* 442 * Divert socket does not support listen(2), 443 * so this should never be called. 444 */ 445 panic("div_abort is called"); 446 } 447 448 static void 449 div_disconnect(netmsg_t msg) 450 { 451 struct socket *so = msg->disconnect.base.nm_so; 452 int error; 453 454 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 455 ("not in netisr0")); 456 457 if (so->so_state & SS_ISCONNECTED) { 458 soisdisconnected(so); 459 error = 0; 460 } else { 461 error = ENOTCONN; 462 } 463 lwkt_replymsg(&msg->disconnect.base.lmsg, error); 464 } 465 466 static void 467 div_bind(netmsg_t msg) 468 { 469 struct socket *so = msg->bind.base.nm_so; 470 struct sockaddr *nam = msg->bind.nm_nam; 471 int error; 472 473 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 474 ("not in netisr0")); 475 476 /* 477 * in_pcbbind assumes that nam is a sockaddr_in 478 * and in_pcbbind requires a valid address. Since divert 479 * sockets don't we need to make sure the address is 480 * filled in properly. 481 * XXX -- divert should not be abusing in_pcbind 482 * and should probably have its own family. 483 */ 484 if (nam->sa_family != AF_INET) { 485 error = EAFNOSUPPORT; 486 } else { 487 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY; 488 error = in_pcbbind(so->so_pcb, nam, msg->bind.nm_td); 489 } 490 lwkt_replymsg(&msg->bind.base.lmsg, error); 491 } 492 493 static void 494 div_shutdown(netmsg_t msg) 495 { 496 struct socket *so = msg->shutdown.base.nm_so; 497 498 KASSERT(&curthread->td_msgport == netisr_cpuport(0), 499 ("not in netisr0")); 500 501 socantsendmore(so); 502 503 lwkt_replymsg(&msg->shutdown.base.lmsg, 0); 504 } 505 506 static void 507 div_send(netmsg_t msg) 508 { 509 struct socket *so = msg->send.base.nm_so; 510 struct mbuf *m = msg->send.nm_m; 511 struct sockaddr *nam = msg->send.nm_addr; 512 struct mbuf *control = msg->send.nm_control; 513 int error; 514 515 /* Length check already done in ip_hashfn() */ 516 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf")); 517 518 /* Send packet */ 519 error = div_output(so, m, (struct sockaddr_in *)nam, control); 520 lwkt_replymsg(&msg->send.base.lmsg, error); 521 } 522 523 SYSCTL_DECL(_net_inet_divert); 524 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, &divcbinfo, 1, 525 in_pcblist_global, "S,xinpcb", "List of active divert sockets"); 526 527 struct pr_usrreqs div_usrreqs = { 528 .pru_abort = div_abort, 529 .pru_accept = pr_generic_notsupp, 530 .pru_attach = div_attach, 531 .pru_bind = div_bind, 532 .pru_connect = pr_generic_notsupp, 533 .pru_connect2 = pr_generic_notsupp, 534 .pru_control = in_control_dispatch, 535 .pru_detach = div_detach, 536 .pru_disconnect = div_disconnect, 537 .pru_listen = pr_generic_notsupp, 538 .pru_peeraddr = in_setpeeraddr_dispatch, 539 .pru_rcvd = pr_generic_notsupp, 540 .pru_rcvoob = pr_generic_notsupp, 541 .pru_send = div_send, 542 .pru_sense = pru_sense_null, 543 .pru_shutdown = div_shutdown, 544 .pru_sockaddr = in_setsockaddr_dispatch, 545 .pru_sosend = sosend, 546 .pru_soreceive = soreceive 547 }; 548 549 static struct mbuf * 550 ip_divert_out(struct mbuf *m, int tee) 551 { 552 struct mbuf *clone = NULL; 553 struct ip *ip = mtod(m, struct ip *); 554 555 /* Clone packet if we're doing a 'tee' */ 556 if (tee) 557 clone = m_dup(m, MB_DONTWAIT); 558 559 /* 560 * XXX 561 * delayed checksums are not currently compatible 562 * with divert sockets. 563 */ 564 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 565 in_delayed_cksum(m); 566 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 567 } 568 569 /* Restore packet header fields to original values */ 570 ip->ip_len = htons(ip->ip_len); 571 ip->ip_off = htons(ip->ip_off); 572 573 /* Deliver packet to divert input routine */ 574 divert_packet(m, 0); 575 576 /* If 'tee', continue with original packet */ 577 return clone; 578 } 579 580 static struct mbuf * 581 ip_divert_in(struct mbuf *m, int tee) 582 { 583 struct mbuf *clone = NULL; 584 struct ip *ip = mtod(m, struct ip *); 585 struct m_tag *mtag; 586 587 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 588 const struct divert_info *divinfo; 589 u_short frag_off; 590 int hlen; 591 592 /* 593 * Only trust divert info in the fragment 594 * at offset 0. 595 */ 596 frag_off = ip->ip_off << 3; 597 if (frag_off != 0) { 598 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL); 599 m_tag_delete(m, mtag); 600 } 601 602 /* 603 * Attempt reassembly; if it succeeds, proceed. 604 * ip_reass() will return a different mbuf. 605 */ 606 m = ip_reass(m); 607 if (m == NULL) 608 return NULL; 609 ip = mtod(m, struct ip *); 610 611 /* Caller need to redispatch the packet, if it is for us */ 612 m->m_pkthdr.fw_flags |= FW_MBUF_REDISPATCH; 613 614 /* 615 * Get the header length of the reassembled 616 * packet 617 */ 618 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 619 620 /* 621 * Restore original checksum before diverting 622 * packet 623 */ 624 ip->ip_len += hlen; 625 ip->ip_len = htons(ip->ip_len); 626 ip->ip_off = htons(ip->ip_off); 627 ip->ip_sum = 0; 628 if (hlen == sizeof(struct ip)) 629 ip->ip_sum = in_cksum_hdr(ip); 630 else 631 ip->ip_sum = in_cksum(m, hlen); 632 ip->ip_off = ntohs(ip->ip_off); 633 ip->ip_len = ntohs(ip->ip_len); 634 635 /* 636 * Only use the saved divert info 637 */ 638 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL); 639 if (mtag == NULL) { 640 /* Wrongly configured ipfw */ 641 kprintf("ip_input no divert info\n"); 642 m_freem(m); 643 return NULL; 644 } 645 divinfo = m_tag_data(mtag); 646 tee = divinfo->tee; 647 } 648 649 /* 650 * Divert or tee packet to the divert protocol if 651 * required. 652 */ 653 654 /* Clone packet if we're doing a 'tee' */ 655 if (tee) 656 clone = m_dup(m, MB_DONTWAIT); 657 658 /* 659 * Restore packet header fields to original 660 * values 661 */ 662 ip->ip_len = htons(ip->ip_len); 663 ip->ip_off = htons(ip->ip_off); 664 665 /* Deliver packet to divert input routine */ 666 divert_packet(m, 1); 667 668 /* Catch invalid reference */ 669 m = NULL; 670 ip = NULL; 671 672 ipstat.ips_delivered++; 673 674 /* If 'tee', continue with original packet */ 675 if (clone != NULL) { 676 /* 677 * Complete processing of the packet. 678 * XXX Better safe than sorry, remove the DIVERT tag. 679 */ 680 mtag = m_tag_find(clone, PACKET_TAG_IPFW_DIVERT, NULL); 681 KKASSERT(mtag != NULL); 682 m_tag_delete(clone, mtag); 683 } 684 return clone; 685 } 686 687 static struct mbuf * 688 ip_divert(struct mbuf *m, int tee, int incoming) 689 { 690 struct mbuf *ret; 691 692 if (incoming) 693 ret = ip_divert_in(m, tee); 694 else 695 ret = ip_divert_out(m, tee); 696 return ret; 697 } 698