Merge branch 'vendor/OPENSSH'
[dragonfly.git] / sys / netinet / ip_divert.c
CommitLineData
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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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: src/sys/netinet/ip_divert.c,v 1.42.2.6 2003/01/23 21:06:45 sam Exp $
87b66be9 34 * $DragonFly: src/sys/netinet/ip_divert.c,v 1.40 2008/10/21 13:51:01 sephe Exp $
984263bc
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35 */
36
0030d31a
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37#define _IP_VHL
38
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39#include "opt_inet.h"
40#include "opt_ipfw.h"
41#include "opt_ipdivert.h"
42#include "opt_ipsec.h"
43
44#ifndef INET
45#error "IPDIVERT requires INET."
46#endif
47
48#include <sys/param.h>
49#include <sys/kernel.h>
50#include <sys/malloc.h>
51#include <sys/mbuf.h>
52#include <sys/socket.h>
53#include <sys/protosw.h>
54#include <sys/socketvar.h>
55#include <sys/sysctl.h>
56#include <sys/systm.h>
57#include <sys/proc.h>
895c1f85 58#include <sys/priv.h>
1cae611f 59#include <sys/thread2.h>
0030d31a 60#include <sys/in_cksum.h>
87b66be9 61#include <sys/lock.h>
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62#ifdef SMP
63#include <sys/msgport.h>
64#endif
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65
66#include <vm/vm_zone.h>
67
68#include <net/if.h>
69#include <net/route.h>
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70#ifdef SMP
71#include <net/netmsg2.h>
72#endif
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73
74#include <netinet/in.h>
75#include <netinet/in_systm.h>
76#include <netinet/ip.h>
77#include <netinet/in_pcb.h>
78#include <netinet/in_var.h>
79#include <netinet/ip_var.h>
68edaf54 80#include <netinet/ip_divert.h>
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81
82/*
83 * Divert sockets
84 */
85
86/*
87 * Allocate enough space to hold a full IP packet
88 */
89#define DIVSNDQ (65536 + 100)
90#define DIVRCVQ (65536 + 100)
91
934c6849
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92#define DIV_IS_OUTPUT(sin) ((sin) == NULL || (sin)->sin_addr.s_addr == 0)
93
6f3f81a8
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94#define DIV_OUTPUT 0x10000
95#define DIV_INPUT 0x20000
96
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97/*
98 * Divert sockets work in conjunction with ipfw, see the divert(4)
99 * manpage for features.
100 * Internally, packets selected by ipfw in ip_input() or ip_output(),
101 * and never diverted before, are passed to the input queue of the
102 * divert socket with a given 'divert_port' number (as specified in
103 * the matching ipfw rule), and they are tagged with a 16 bit cookie
104 * (representing the rule number of the matching ipfw rule), which
105 * is passed to process reading from the socket.
106 *
107 * Packets written to the divert socket are again tagged with a cookie
108 * (usually the same as above) and a destination address.
109 * If the destination address is INADDR_ANY then the packet is
110 * treated as outgoing and sent to ip_output(), otherwise it is
111 * treated as incoming and sent to ip_input().
112 * In both cases, the packet is tagged with the cookie.
113 *
114 * On reinjection, processing in ip_input() and ip_output()
115 * will be exactly the same as for the original packet, except that
116 * ipfw processing will start at the rule number after the one
117 * written in the cookie (so, tagging a packet with a cookie of 0
118 * will cause it to be effectively considered as a standard packet).
119 */
120
121/* Internal variables */
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122static struct inpcbinfo divcbinfo;
123
124static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
125static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
126
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127static struct mbuf *ip_divert(struct mbuf *, int, int);
128
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129/*
130 * Initialize divert connection block queue.
131 */
132void
133div_init(void)
134{
d2e9e54c 135 in_pcbinfo_init(&divcbinfo);
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136 /*
137 * XXX We don't use the hash list for divert IP, but it's easier
138 * to allocate a one entry hash list than it is to check all
139 * over the place for hashbase == NULL.
140 */
141 divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
142 divcbinfo.porthashbase = hashinit(1, M_PCB, &divcbinfo.porthashmask);
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143 divcbinfo.wildcardhashbase = hashinit(1, M_PCB,
144 &divcbinfo.wildcardhashmask);
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145 divcbinfo.ipi_zone = zinit("divcb", sizeof(struct inpcb),
146 maxsockets, ZONE_INTERRUPT, 0);
0030d31a 147 ip_divert_p = ip_divert;
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148}
149
150/*
151 * IPPROTO_DIVERT is not a real IP protocol; don't allow any packets
152 * with that protocol number to enter the system from the outside.
153 */
154void
a00138cb 155div_input(struct mbuf *m, ...)
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156{
157 ipstat.ips_noproto++;
158 m_freem(m);
159}
160
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161struct lwkt_port *
162div_soport(struct socket *so, struct sockaddr *nam,
163 struct mbuf **mptr, int req)
164{
165 struct sockaddr_in *sin;
166 struct mbuf *m;
167 int dir;
168
169 /* Except for send(), everything happens on CPU0 */
170 if (req != PRU_SEND)
171 return cpu0_soport(so, nam, mptr, req);
172
173 sin = (struct sockaddr_in *)nam;
174 m = *mptr;
175 M_ASSERTPKTHDR(m);
176
177 m->m_pkthdr.rcvif = NULL;
178 dir = DIV_IS_OUTPUT(sin) ? IP_MPORT_OUT : IP_MPORT_IN;
179
180 if (sin != NULL) {
181 int i;
182
183 /*
184 * Try locating the interface, if we originally had one.
185 * This is done even for outgoing packets, since for a
186 * forwarded packet, there must be an interface attached.
187 *
188 * Find receive interface with the given name, stuffed
189 * (if it exists) in the sin_zero[] field.
190 * The name is user supplied data so don't trust its size
191 * or that it is zero terminated.
192 */
193 for (i = 0; sin->sin_zero[i] && i < sizeof(sin->sin_zero); i++)
194 ;
195 if (i > 0 && i < sizeof(sin->sin_zero))
196 m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
197 }
198
199 if (dir == IP_MPORT_IN && m->m_pkthdr.rcvif == NULL) {
200 /*
201 * No luck with the name, check by IP address.
202 * Clear the port and the ifname to make sure
203 * there are no distractions for ifa_ifwithaddr.
204 *
205 * Be careful not to trash sin->sin_port; it will
206 * be used later in div_output().
207 */
208 struct ifaddr *ifa;
209 u_short sin_port;
210
211 bzero(sin->sin_zero, sizeof(sin->sin_zero));
212 sin_port = sin->sin_port; /* save */
213 sin->sin_port = 0;
214 ifa = ifa_ifwithaddr((struct sockaddr *)sin);
215 if (ifa == NULL) {
216 m_freem(m);
217 *mptr = NULL;
218 return NULL;
219 }
220 sin->sin_port = sin_port; /* restore */
221 m->m_pkthdr.rcvif = ifa->ifa_ifp;
222 }
223
224 return ip_mport(mptr, dir);
225}
226
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227/*
228 * Divert a packet by passing it up to the divert socket at port 'port'.
229 *
230 * Setup generic address and protocol structures for div_input routine,
231 * then pass them along with mbuf chain.
232 */
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233static void
234div_packet(struct mbuf *m, int incoming, int port)
984263bc 235{
668488bd 236 struct sockaddr_in divsrc = { sizeof divsrc, AF_INET };
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237 struct inpcb *inp;
238 struct socket *sa;
e5ecc832 239 struct m_tag *mtag;
68edaf54 240 struct divert_info *divinfo;
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241 u_int16_t nport;
242
68edaf54 243 /* Locate the divert info */
077c74e2 244 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
68edaf54
SZ
245 divinfo = m_tag_data(mtag);
246 divsrc.sin_port = divinfo->skipto;
077c74e2 247
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248 /*
249 * Record receive interface address, if any.
250 * But only for incoming packets.
251 */
252 divsrc.sin_addr.s_addr = 0;
253 if (incoming) {
b2632176 254 struct ifaddr_container *ifac;
984263bc 255
984263bc 256 /* Find IP address for receive interface */
b2632176
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257 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
258 ifa_link) {
259 struct ifaddr *ifa = ifac->ifa;
260
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261 if (ifa->ifa_addr == NULL)
262 continue;
263 if (ifa->ifa_addr->sa_family != AF_INET)
264 continue;
265 divsrc.sin_addr =
266 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
267 break;
268 }
269 }
270 /*
271 * Record the incoming interface name whenever we have one.
272 */
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273 if (m->m_pkthdr.rcvif) {
274 /*
f23061d4 275 * Hide the actual interface name in there in the
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276 * sin_zero array. XXX This needs to be moved to a
277 * different sockaddr type for divert, e.g.
f23061d4 278 * sockaddr_div with multiple fields like
984263bc
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279 * sockaddr_dl. Presently we have only 7 bytes
280 * but that will do for now as most interfaces
281 * are 4 or less + 2 or less bytes for unit.
282 * There is probably a faster way of doing this,
283 * possibly taking it from the sockaddr_dl on the iface.
284 * This solves the problem of a P2P link and a LAN interface
285 * having the same address, which can result in the wrong
286 * interface being assigned to the packet when fed back
287 * into the divert socket. Theoretically if the daemon saves
288 * and re-uses the sockaddr_in as suggested in the man pages,
289 * this iface name will come along for the ride.
290 * (see div_output for the other half of this.)
f23061d4 291 */
f8c7a42d 292 ksnprintf(divsrc.sin_zero, sizeof divsrc.sin_zero,
87b66be9 293 m->m_pkthdr.rcvif->if_xname);
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294 }
295
296 /* Put packet on socket queue, if any */
297 sa = NULL;
298 nport = htons((u_int16_t)port);
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299
300 /*
301 * XXX
302 * Following loop to locate the inpcb is MPSAFE since the inpcb
303 * insertion/removal happens on the same CPU (CPU0), however,
304 * saving/testing the socket pointer is not MPSAFE. So we still
305 * need to hold BGL here.
306 */
307 get_mplock();
d2e9e54c
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308 LIST_FOREACH(inp, &divcbinfo.pcblisthead, inp_list) {
309 if (inp->inp_flags & INP_PLACEMARKER)
310 continue;
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311 if (inp->inp_lport == nport)
312 sa = inp->inp_socket;
313 }
314 if (sa) {
6d49aa6f 315 if (ssb_appendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc, m,
2038fb68 316 NULL) == 0)
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317 m_freem(m);
318 else
319 sorwakeup(sa);
87b66be9 320 rel_mplock();
984263bc 321 } else {
87b66be9 322 rel_mplock();
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323 m_freem(m);
324 ipstat.ips_noproto++;
325 ipstat.ips_delivered--;
f23061d4 326 }
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327}
328
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329#ifdef SMP
330static void
331div_packet_handler(struct netmsg *nmsg)
332{
333 struct netmsg_packet *nmp;
334 struct lwkt_msg *msg;
335 struct mbuf *m;
336 int port, incoming = 0;
337
338 nmp = (struct netmsg_packet *)nmsg;
339 m = nmp->nm_packet;
340
341 msg = &nmsg->nm_lmsg;
342 port = msg->u.ms_result32 & 0xffff;
343 if (msg->u.ms_result32 & DIV_INPUT)
344 incoming = 1;
345
346 div_packet(m, incoming, port);
347}
348#endif /* SMP */
349
0030d31a 350static void
b0cb7c2c 351divert_packet(struct mbuf *m, int incoming)
6f3f81a8 352{
b0cb7c2c
SZ
353 struct m_tag *mtag;
354 struct divert_info *divinfo;
355 int port;
356
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SZ
357 M_ASSERTPKTHDR(m);
358
359 /* Assure header */
360 if (m->m_len < sizeof(struct ip) &&
361 (m = m_pullup(m, sizeof(struct ip))) == NULL)
362 return;
363
b0cb7c2c
SZ
364 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
365 KASSERT(mtag != NULL, ("%s no divert tag!", __func__));
366 divinfo = m_tag_data(mtag);
367
368 port = divinfo->port;
369 KASSERT(port != 0, ("%s: port=0", __func__));
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370
371#ifdef SMP
372 if (mycpuid != 0) {
373 struct netmsg_packet *nmp;
374 struct lwkt_msg *msg;
375
376 nmp = &m->m_hdr.mh_netmsg;
87b66be9 377 netmsg_init(&nmp->nm_netmsg, &netisr_apanic_rport, MSGF_MPSAFE,
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SZ
378 div_packet_handler);
379 nmp->nm_packet = m;
380
381 msg = &nmp->nm_netmsg.nm_lmsg;
382 msg->u.ms_result32 = port; /* port is 16bits */
383 if (incoming)
384 msg->u.ms_result32 |= DIV_INPUT;
385 else
386 msg->u.ms_result32 |= DIV_OUTPUT;
387
388 lwkt_sendmsg(cpu_portfn(0), &nmp->nm_netmsg.nm_lmsg);
389 } else
390#endif
391 div_packet(m, incoming, port);
392}
393
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394/*
395 * Deliver packet back into the IP processing machinery.
396 *
397 * If no address specified, or address is 0.0.0.0, send to ip_output();
398 * otherwise, send to ip_input() and mark as having been received on
399 * the interface with that address.
400 */
401static int
402div_output(struct socket *so, struct mbuf *m,
403 struct sockaddr_in *sin, struct mbuf *control)
404{
405 int error = 0;
e5ecc832 406 struct m_tag *mtag;
68edaf54 407 struct divert_info *divinfo;
984263bc 408
934c6849
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409 if (control)
410 m_freem(control); /* XXX */
411
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MD
412 /*
413 * Prepare the tag for divert info. Note that a packet
414 * with a 0 tag in mh_data is effectively untagged,
415 * so we could optimize that case.
416 */
68edaf54 417 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT, sizeof(*divinfo), MB_DONTWAIT);
e5ecc832
JS
418 if (mtag == NULL) {
419 error = ENOBUFS;
420 goto cantsend;
421 }
422 m_tag_prepend(m, mtag);
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423
424 /* Loopback avoidance and state recovery */
68edaf54 425 divinfo = m_tag_data(mtag);
934c6849 426 if (sin)
68edaf54 427 divinfo->skipto = sin->sin_port;
934c6849 428 else
68edaf54 429 divinfo->skipto = 0;
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430
431 /* Reinject packet into the system as incoming or outgoing */
934c6849 432 if (DIV_IS_OUTPUT(sin)) {
984263bc
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433 struct ip *const ip = mtod(m, struct ip *);
434
b171561b
SZ
435 /* Don't allow packet length sizes that will crash */
436 if ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len) {
984263bc
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437 error = EINVAL;
438 goto cantsend;
439 }
440
441 /* Convert fields to host order for ip_output() */
442 ip->ip_len = ntohs(ip->ip_len);
443 ip->ip_off = ntohs(ip->ip_off);
444
445 /* Send packet to output processing */
446 ipstat.ips_rawout++; /* XXX */
b171561b 447 error = ip_output(m, NULL, NULL,
984263bc
MD
448 (so->so_options & SO_DONTROUTE) |
449 IP_ALLOWBROADCAST | IP_RAWOUTPUT,
b171561b 450 NULL, NULL);
984263bc 451 } else {
e5ecc832 452 ip_input(m);
984263bc 453 }
984263bc
MD
454 return error;
455
456cantsend:
457 m_freem(m);
458 return error;
459}
460
461static int
e4700d00 462div_attach(struct socket *so, int proto, struct pru_attach_info *ai)
984263bc
MD
463{
464 struct inpcb *inp;
1cae611f 465 int error;
984263bc 466
ed894f8c 467 inp = so->so_pcb;
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MD
468 if (inp)
469 panic("div_attach");
895c1f85 470 if ((error = priv_check_cred(ai->p_ucred, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
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MD
471 return error;
472
e4700d00 473 error = soreserve(so, div_sendspace, div_recvspace, ai->sb_rlimit);
984263bc
MD
474 if (error)
475 return error;
e4700d00 476 error = in_pcballoc(so, &divcbinfo);
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MD
477 if (error)
478 return error;
479 inp = (struct inpcb *)so->so_pcb;
480 inp->inp_ip_p = proto;
481 inp->inp_vflag |= INP_IPV4;
482 inp->inp_flags |= INP_HDRINCL;
5fe66e68
JH
483 /*
484 * The socket is always "connected" because
485 * we always know "where" to send the packet.
486 */
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487 so->so_state |= SS_ISCONNECTED;
488 return 0;
489}
490
491static int
492div_detach(struct socket *so)
493{
494 struct inpcb *inp;
495
ed894f8c 496 inp = so->so_pcb;
5fe66e68 497 if (inp == NULL)
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498 panic("div_detach");
499 in_pcbdetach(inp);
500 return 0;
501}
502
503static int
504div_abort(struct socket *so)
505{
506 soisdisconnected(so);
507 return div_detach(so);
508}
509
510static int
511div_disconnect(struct socket *so)
512{
5fe66e68 513 if (!(so->so_state & SS_ISCONNECTED))
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514 return ENOTCONN;
515 return div_abort(so);
516}
517
518static int
dadab5e9 519div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
984263bc 520{
984263bc
MD
521 int error;
522
65b1ea7e
SZ
523 /*
524 * in_pcbbind assumes that nam is a sockaddr_in
984263bc
MD
525 * and in_pcbbind requires a valid address. Since divert
526 * sockets don't we need to make sure the address is
527 * filled in properly.
528 * XXX -- divert should not be abusing in_pcbind
529 * and should probably have its own family.
530 */
65b1ea7e 531 if (nam->sa_family != AF_INET) {
984263bc 532 error = EAFNOSUPPORT;
65b1ea7e 533 } else {
984263bc 534 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
65b1ea7e 535 error = in_pcbbind(so->so_pcb, nam, td);
984263bc 536 }
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MD
537 return error;
538}
539
540static int
541div_shutdown(struct socket *so)
542{
543 socantsendmore(so);
544 return 0;
545}
546
547static int
548div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
dadab5e9 549 struct mbuf *control, struct thread *td)
984263bc 550{
934c6849
SZ
551 /* Length check already done in ip_mport() */
552 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
984263bc
MD
553
554 /* Send packet */
555 return div_output(so, m, (struct sockaddr_in *)nam, control);
556}
557
984263bc 558SYSCTL_DECL(_net_inet_divert);
48a2763f
JS
559SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, &divcbinfo, 0,
560 in_pcblist_global, "S,xinpcb", "List of active divert sockets");
984263bc
MD
561
562struct pr_usrreqs div_usrreqs = {
fa5e758c
MD
563 .pru_abort = div_abort,
564 .pru_accept = pru_accept_notsupp,
565 .pru_attach = div_attach,
566 .pru_bind = div_bind,
567 .pru_connect = pru_connect_notsupp,
568 .pru_connect2 = pru_connect2_notsupp,
569 .pru_control = in_control,
570 .pru_detach = div_detach,
571 .pru_disconnect = div_disconnect,
572 .pru_listen = pru_listen_notsupp,
573 .pru_peeraddr = in_setpeeraddr,
574 .pru_rcvd = pru_rcvd_notsupp,
575 .pru_rcvoob = pru_rcvoob_notsupp,
576 .pru_send = div_send,
577 .pru_sense = pru_sense_null,
578 .pru_shutdown = div_shutdown,
579 .pru_sockaddr = in_setsockaddr,
580 .pru_sosend = sosend,
581 .pru_soreceive = soreceive,
582 .pru_sopoll = sopoll
984263bc 583};
0030d31a
SZ
584
585static struct mbuf *
586ip_divert_out(struct mbuf *m, int tee)
587{
588 struct mbuf *clone = NULL;
589 struct ip *ip = mtod(m, struct ip *);
590
591 /* Clone packet if we're doing a 'tee' */
592 if (tee)
593 clone = m_dup(m, MB_DONTWAIT);
594
595 /*
596 * XXX
597 * delayed checksums are not currently compatible
598 * with divert sockets.
599 */
600 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
601 in_delayed_cksum(m);
602 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
603 }
604
605 /* Restore packet header fields to original values */
606 ip->ip_len = htons(ip->ip_len);
607 ip->ip_off = htons(ip->ip_off);
608
609 /* Deliver packet to divert input routine */
610 divert_packet(m, 0);
611
612 /* If 'tee', continue with original packet */
613 return clone;
614}
615
616static struct mbuf *
617ip_divert_in(struct mbuf *m, int tee)
618{
619 struct mbuf *clone = NULL;
620 struct ip *ip = mtod(m, struct ip *);
621 struct m_tag *mtag;
622
623 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
624 const struct divert_info *divinfo;
625 u_short frag_off;
626 int hlen;
627
628 /*
629 * Only trust divert info in the fragment
630 * at offset 0.
631 */
632 frag_off = ip->ip_off << 3;
633 if (frag_off != 0) {
634 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
635 m_tag_delete(m, mtag);
636 }
637
638 /*
639 * Attempt reassembly; if it succeeds, proceed.
640 * ip_reass() will return a different mbuf.
641 */
642 m = ip_reass(m);
643 if (m == NULL)
644 return NULL;
645 ip = mtod(m, struct ip *);
646
647 /* Caller need to redispatch the packet, if it is for us */
648 m->m_pkthdr.fw_flags |= FW_MBUF_REDISPATCH;
649
650 /*
651 * Get the header length of the reassembled
652 * packet
653 */
654 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
655
656 /*
657 * Restore original checksum before diverting
658 * packet
659 */
660 ip->ip_len += hlen;
661 ip->ip_len = htons(ip->ip_len);
662 ip->ip_off = htons(ip->ip_off);
663 ip->ip_sum = 0;
664 if (hlen == sizeof(struct ip))
665 ip->ip_sum = in_cksum_hdr(ip);
666 else
667 ip->ip_sum = in_cksum(m, hlen);
668 ip->ip_off = ntohs(ip->ip_off);
669 ip->ip_len = ntohs(ip->ip_len);
670
671 /*
672 * Only use the saved divert info
673 */
674 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
675 if (mtag == NULL) {
676 /* Wrongly configured ipfw */
677 kprintf("ip_input no divert info\n");
678 m_freem(m);
679 return NULL;
680 }
681 divinfo = m_tag_data(mtag);
682 tee = divinfo->tee;
683 }
684
685 /*
686 * Divert or tee packet to the divert protocol if
687 * required.
688 */
689
690 /* Clone packet if we're doing a 'tee' */
691 if (tee)
692 clone = m_dup(m, MB_DONTWAIT);
693
694 /*
695 * Restore packet header fields to original
696 * values
697 */
698 ip->ip_len = htons(ip->ip_len);
699 ip->ip_off = htons(ip->ip_off);
700
701 /* Deliver packet to divert input routine */
702 divert_packet(m, 1);
703
704 /* Catch invalid reference */
705 m = NULL;
706 ip = NULL;
707
708 ipstat.ips_delivered++;
709
710 /* If 'tee', continue with original packet */
711 if (clone != NULL) {
712 /*
713 * Complete processing of the packet.
714 * XXX Better safe than sorry, remove the DIVERT tag.
715 */
716 mtag = m_tag_find(clone, PACKET_TAG_IPFW_DIVERT, NULL);
717 KKASSERT(mtag != NULL);
718 m_tag_delete(clone, mtag);
719 }
720 return clone;
721}
722
723static struct mbuf *
724ip_divert(struct mbuf *m, int tee, int incoming)
725{
726 struct mbuf *ret;
727
728 if (incoming)
729 ret = ip_divert_in(m, tee);
730 else
731 ret = ip_divert_out(m, tee);
732 return ret;
733}