HAMMER 60I/Many: Mirroring
[dragonfly.git] / sys / netinet / ip_divert.c
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1 /*
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
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.
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.
33 * $FreeBSD: src/sys/netinet/ip_divert.c,v 1.42.2.6 2003/01/23 21:06:45 sam Exp $
34 * $DragonFly: src/sys/netinet/ip_divert.c,v 1.36 2008/03/07 11:34:20 sephe Exp $
37 #include "opt_inet.h"
38 #include "opt_ipfw.h"
39 #include "opt_ipdivert.h"
40 #include "opt_ipsec.h"
42 #ifndef INET
43 #error "IPDIVERT requires INET."
44 #endif
46 #include <sys/param.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/socket.h>
51 #include <sys/protosw.h>
52 #include <sys/socketvar.h>
53 #include <sys/sysctl.h>
54 #include <sys/systm.h>
55 #include <sys/proc.h>
56 #include <sys/thread2.h>
57 #ifdef SMP
58 #include <sys/msgport.h>
59 #endif
61 #include <vm/vm_zone.h>
63 #include <net/if.h>
64 #include <net/route.h>
65 #ifdef SMP
66 #include <net/netmsg2.h>
67 #endif
69 #include <netinet/in.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/ip.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/in_var.h>
74 #include <netinet/ip_var.h>
77 * Divert sockets
81 * Allocate enough space to hold a full IP packet
83 #define DIVSNDQ (65536 + 100)
84 #define DIVRCVQ (65536 + 100)
86 #define DIV_IS_OUTPUT(sin) ((sin) == NULL || (sin)->sin_addr.s_addr == 0)
88 #define DIV_OUTPUT 0x10000
89 #define DIV_INPUT 0x20000
92 * Divert sockets work in conjunction with ipfw, see the divert(4)
93 * manpage for features.
94 * Internally, packets selected by ipfw in ip_input() or ip_output(),
95 * and never diverted before, are passed to the input queue of the
96 * divert socket with a given 'divert_port' number (as specified in
97 * the matching ipfw rule), and they are tagged with a 16 bit cookie
98 * (representing the rule number of the matching ipfw rule), which
99 * is passed to process reading from the socket.
101 * Packets written to the divert socket are again tagged with a cookie
102 * (usually the same as above) and a destination address.
103 * If the destination address is INADDR_ANY then the packet is
104 * treated as outgoing and sent to ip_output(), otherwise it is
105 * treated as incoming and sent to ip_input().
106 * In both cases, the packet is tagged with the cookie.
108 * On reinjection, processing in ip_input() and ip_output()
109 * will be exactly the same as for the original packet, except that
110 * ipfw processing will start at the rule number after the one
111 * written in the cookie (so, tagging a packet with a cookie of 0
112 * will cause it to be effectively considered as a standard packet).
115 /* Internal variables */
116 static struct inpcbinfo divcbinfo;
118 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
119 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
122 * Initialize divert connection block queue.
124 void
125 div_init(void)
127 in_pcbinfo_init(&divcbinfo);
129 * XXX We don't use the hash list for divert IP, but it's easier
130 * to allocate a one entry hash list than it is to check all
131 * over the place for hashbase == NULL.
133 divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
134 divcbinfo.porthashbase = hashinit(1, M_PCB, &divcbinfo.porthashmask);
135 divcbinfo.wildcardhashbase = hashinit(1, M_PCB,
136 &divcbinfo.wildcardhashmask);
137 divcbinfo.ipi_zone = zinit("divcb", sizeof(struct inpcb),
138 maxsockets, ZONE_INTERRUPT, 0);
142 * IPPROTO_DIVERT is not a real IP protocol; don't allow any packets
143 * with that protocol number to enter the system from the outside.
145 void
146 div_input(struct mbuf *m, ...)
148 ipstat.ips_noproto++;
149 m_freem(m);
152 struct lwkt_port *
153 div_soport(struct socket *so, struct sockaddr *nam,
154 struct mbuf **mptr, int req)
156 struct sockaddr_in *sin;
157 struct mbuf *m;
158 int dir;
160 /* Except for send(), everything happens on CPU0 */
161 if (req != PRU_SEND)
162 return cpu0_soport(so, nam, mptr, req);
164 sin = (struct sockaddr_in *)nam;
165 m = *mptr;
166 M_ASSERTPKTHDR(m);
168 m->m_pkthdr.rcvif = NULL;
169 dir = DIV_IS_OUTPUT(sin) ? IP_MPORT_OUT : IP_MPORT_IN;
171 if (sin != NULL) {
172 int i;
175 * Try locating the interface, if we originally had one.
176 * This is done even for outgoing packets, since for a
177 * forwarded packet, there must be an interface attached.
179 * Find receive interface with the given name, stuffed
180 * (if it exists) in the sin_zero[] field.
181 * The name is user supplied data so don't trust its size
182 * or that it is zero terminated.
184 for (i = 0; sin->sin_zero[i] && i < sizeof(sin->sin_zero); i++)
186 if (i > 0 && i < sizeof(sin->sin_zero))
187 m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
190 if (dir == IP_MPORT_IN && m->m_pkthdr.rcvif == NULL) {
192 * No luck with the name, check by IP address.
193 * Clear the port and the ifname to make sure
194 * there are no distractions for ifa_ifwithaddr.
196 * Be careful not to trash sin->sin_port; it will
197 * be used later in div_output().
199 struct ifaddr *ifa;
200 u_short sin_port;
202 bzero(sin->sin_zero, sizeof(sin->sin_zero));
203 sin_port = sin->sin_port; /* save */
204 sin->sin_port = 0;
205 ifa = ifa_ifwithaddr((struct sockaddr *)sin);
206 if (ifa == NULL) {
207 m_freem(m);
208 *mptr = NULL;
209 return NULL;
211 sin->sin_port = sin_port; /* restore */
212 m->m_pkthdr.rcvif = ifa->ifa_ifp;
215 return ip_mport(mptr, dir);
219 * Divert a packet by passing it up to the divert socket at port 'port'.
221 * Setup generic address and protocol structures for div_input routine,
222 * then pass them along with mbuf chain.
224 static void
225 div_packet(struct mbuf *m, int incoming, int port)
227 struct sockaddr_in divsrc = { sizeof divsrc, AF_INET };
228 struct inpcb *inp;
229 struct socket *sa;
230 struct m_tag *mtag;
231 u_int16_t nport;
233 /* Locate the divert tag */
234 mtag = m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL);
235 divsrc.sin_port = *(u_int16_t *)m_tag_data(mtag);
238 * Record receive interface address, if any.
239 * But only for incoming packets.
241 divsrc.sin_addr.s_addr = 0;
242 if (incoming) {
243 struct ifaddr_container *ifac;
245 /* Find IP address for receive interface */
246 TAILQ_FOREACH(ifac, &m->m_pkthdr.rcvif->if_addrheads[mycpuid],
247 ifa_link) {
248 struct ifaddr *ifa = ifac->ifa;
250 if (ifa->ifa_addr == NULL)
251 continue;
252 if (ifa->ifa_addr->sa_family != AF_INET)
253 continue;
254 divsrc.sin_addr =
255 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
256 break;
260 * Record the incoming interface name whenever we have one.
262 if (m->m_pkthdr.rcvif) {
264 * Hide the actual interface name in there in the
265 * sin_zero array. XXX This needs to be moved to a
266 * different sockaddr type for divert, e.g.
267 * sockaddr_div with multiple fields like
268 * sockaddr_dl. Presently we have only 7 bytes
269 * but that will do for now as most interfaces
270 * are 4 or less + 2 or less bytes for unit.
271 * There is probably a faster way of doing this,
272 * possibly taking it from the sockaddr_dl on the iface.
273 * This solves the problem of a P2P link and a LAN interface
274 * having the same address, which can result in the wrong
275 * interface being assigned to the packet when fed back
276 * into the divert socket. Theoretically if the daemon saves
277 * and re-uses the sockaddr_in as suggested in the man pages,
278 * this iface name will come along for the ride.
279 * (see div_output for the other half of this.)
281 ksnprintf(divsrc.sin_zero, sizeof divsrc.sin_zero,
282 m->m_pkthdr.rcvif->if_xname);
285 /* Put packet on socket queue, if any */
286 sa = NULL;
287 nport = htons((u_int16_t)port);
288 LIST_FOREACH(inp, &divcbinfo.pcblisthead, inp_list) {
289 if (inp->inp_flags & INP_PLACEMARKER)
290 continue;
291 if (inp->inp_lport == nport)
292 sa = inp->inp_socket;
294 if (sa) {
295 if (ssb_appendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc, m,
296 (struct mbuf *)NULL) == 0)
297 m_freem(m);
298 else
299 sorwakeup(sa);
300 } else {
301 m_freem(m);
302 ipstat.ips_noproto++;
303 ipstat.ips_delivered--;
307 #ifdef SMP
308 static void
309 div_packet_handler(struct netmsg *nmsg)
311 struct netmsg_packet *nmp;
312 struct lwkt_msg *msg;
313 struct mbuf *m;
314 int port, incoming = 0;
316 nmp = (struct netmsg_packet *)nmsg;
317 m = nmp->nm_packet;
319 msg = &nmsg->nm_lmsg;
320 port = msg->u.ms_result32 & 0xffff;
321 if (msg->u.ms_result32 & DIV_INPUT)
322 incoming = 1;
324 div_packet(m, incoming, port);
326 #endif /* SMP */
328 void
329 divert_packet(struct mbuf *m, int incoming, int port)
331 /* Sanity check */
332 KASSERT(port != 0, ("%s: port=0", __func__));
333 M_ASSERTPKTHDR(m);
335 /* Assure header */
336 if (m->m_len < sizeof(struct ip) &&
337 (m = m_pullup(m, sizeof(struct ip))) == NULL)
338 return;
340 /* Sanity check */
341 KASSERT(m_tag_find(m, PACKET_TAG_IPFW_DIVERT, NULL) != NULL,
342 ("%s no divert tag!", __func__));
344 #ifdef SMP
345 if (mycpuid != 0) {
346 struct netmsg_packet *nmp;
347 struct lwkt_msg *msg;
349 nmp = &m->m_hdr.mh_netmsg;
350 netmsg_init(&nmp->nm_netmsg, &netisr_apanic_rport, 0,
351 div_packet_handler);
352 nmp->nm_packet = m;
354 msg = &nmp->nm_netmsg.nm_lmsg;
355 msg->u.ms_result32 = port; /* port is 16bits */
356 if (incoming)
357 msg->u.ms_result32 |= DIV_INPUT;
358 else
359 msg->u.ms_result32 |= DIV_OUTPUT;
361 lwkt_sendmsg(cpu_portfn(0), &nmp->nm_netmsg.nm_lmsg);
362 } else
363 #endif
364 div_packet(m, incoming, port);
368 * Deliver packet back into the IP processing machinery.
370 * If no address specified, or address is 0.0.0.0, send to ip_output();
371 * otherwise, send to ip_input() and mark as having been received on
372 * the interface with that address.
374 static int
375 div_output(struct socket *so, struct mbuf *m,
376 struct sockaddr_in *sin, struct mbuf *control)
378 int error = 0;
379 struct m_tag *mtag;
381 if (control)
382 m_freem(control); /* XXX */
385 * Prepare the tag for divert info. Note that a packet
386 * with a 0 tag in mh_data is effectively untagged,
387 * so we could optimize that case.
389 mtag = m_tag_get(PACKET_TAG_IPFW_DIVERT, sizeof(u_int16_t), MB_DONTWAIT);
390 if (mtag == NULL) {
391 error = ENOBUFS;
392 goto cantsend;
394 m_tag_prepend(m, mtag);
396 /* Loopback avoidance and state recovery */
397 if (sin)
398 *(u_int16_t *)m_tag_data(mtag) = sin->sin_port;
399 else
400 *(u_int16_t *)m_tag_data(mtag) = 0;
402 /* Reinject packet into the system as incoming or outgoing */
403 if (DIV_IS_OUTPUT(sin)) {
404 struct ip *const ip = mtod(m, struct ip *);
406 /* Don't allow packet length sizes that will crash */
407 if ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len) {
408 error = EINVAL;
409 goto cantsend;
412 /* Convert fields to host order for ip_output() */
413 ip->ip_len = ntohs(ip->ip_len);
414 ip->ip_off = ntohs(ip->ip_off);
416 /* Send packet to output processing */
417 ipstat.ips_rawout++; /* XXX */
418 error = ip_output(m, NULL, NULL,
419 (so->so_options & SO_DONTROUTE) |
420 IP_ALLOWBROADCAST | IP_RAWOUTPUT,
421 NULL, NULL);
422 } else {
423 ip_input(m);
425 return error;
427 cantsend:
428 m_freem(m);
429 return error;
432 static int
433 div_attach(struct socket *so, int proto, struct pru_attach_info *ai)
435 struct inpcb *inp;
436 int error;
438 inp = so->so_pcb;
439 if (inp)
440 panic("div_attach");
441 if ((error = suser_cred(ai->p_ucred, NULL_CRED_OKAY)) != 0)
442 return error;
444 error = soreserve(so, div_sendspace, div_recvspace, ai->sb_rlimit);
445 if (error)
446 return error;
447 error = in_pcballoc(so, &divcbinfo);
448 if (error)
449 return error;
450 inp = (struct inpcb *)so->so_pcb;
451 inp->inp_ip_p = proto;
452 inp->inp_vflag |= INP_IPV4;
453 inp->inp_flags |= INP_HDRINCL;
455 * The socket is always "connected" because
456 * we always know "where" to send the packet.
458 so->so_state |= SS_ISCONNECTED;
459 return 0;
462 static int
463 div_detach(struct socket *so)
465 struct inpcb *inp;
467 inp = so->so_pcb;
468 if (inp == NULL)
469 panic("div_detach");
470 in_pcbdetach(inp);
471 return 0;
474 static int
475 div_abort(struct socket *so)
477 soisdisconnected(so);
478 return div_detach(so);
481 static int
482 div_disconnect(struct socket *so)
484 if (!(so->so_state & SS_ISCONNECTED))
485 return ENOTCONN;
486 return div_abort(so);
489 static int
490 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
492 int error;
495 * in_pcbbind assumes that nam is a sockaddr_in
496 * and in_pcbbind requires a valid address. Since divert
497 * sockets don't we need to make sure the address is
498 * filled in properly.
499 * XXX -- divert should not be abusing in_pcbind
500 * and should probably have its own family.
502 if (nam->sa_family != AF_INET) {
503 error = EAFNOSUPPORT;
504 } else {
505 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
506 error = in_pcbbind(so->so_pcb, nam, td);
508 return error;
511 static int
512 div_shutdown(struct socket *so)
514 socantsendmore(so);
515 return 0;
518 static int
519 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
520 struct mbuf *control, struct thread *td)
522 /* Length check already done in ip_mport() */
523 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
525 /* Send packet */
526 return div_output(so, m, (struct sockaddr_in *)nam, control);
529 SYSCTL_DECL(_net_inet_divert);
530 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, &divcbinfo, 0,
531 in_pcblist_global, "S,xinpcb", "List of active divert sockets");
533 struct pr_usrreqs div_usrreqs = {
534 .pru_abort = div_abort,
535 .pru_accept = pru_accept_notsupp,
536 .pru_attach = div_attach,
537 .pru_bind = div_bind,
538 .pru_connect = pru_connect_notsupp,
539 .pru_connect2 = pru_connect2_notsupp,
540 .pru_control = in_control,
541 .pru_detach = div_detach,
542 .pru_disconnect = div_disconnect,
543 .pru_listen = pru_listen_notsupp,
544 .pru_peeraddr = in_setpeeraddr,
545 .pru_rcvd = pru_rcvd_notsupp,
546 .pru_rcvoob = pru_rcvoob_notsupp,
547 .pru_send = div_send,
548 .pru_sense = pru_sense_null,
549 .pru_shutdown = div_shutdown,
550 .pru_sockaddr = in_setsockaddr,
551 .pru_sosend = sosend,
552 .pru_soreceive = soreceive,
553 .pru_sopoll = sopoll