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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /*
23: * Copyright (c) 1982, 1986, 1988, 1993
24: * The Regents of the University of California. All rights reserved.
25: *
26: * Redistribution and use in source and binary forms, with or without
27: * modification, are permitted provided that the following conditions
28: * are met:
29: * 1. Redistributions of source code must retain the above copyright
30: * notice, this list of conditions and the following disclaimer.
31: * 2. Redistributions in binary form must reproduce the above copyright
32: * notice, this list of conditions and the following disclaimer in the
33: * documentation and/or other materials provided with the distribution.
34: * 3. All advertising materials mentioning features or use of this software
35: * must display the following acknowledgement:
36: * This product includes software developed by the University of
37: * California, Berkeley and its contributors.
38: * 4. Neither the name of the University nor the names of its contributors
39: * may be used to endorse or promote products derived from this software
40: * without specific prior written permission.
41: *
42: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
43: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
46: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52: * SUCH DAMAGE.
53: *
54: */
55:
56: #if ISFB31
57: #include "opt_inet.h"
58: #include "opt_ipfw.h"
59: #include "opt_ipdivert.h"
60: #endif
61:
62: #ifndef INET
63: #error "IPDIVERT requires INET."
64: #endif
65:
66: #include <sys/param.h>
67: #include <sys/malloc.h>
68: #include <sys/mbuf.h>
69: #include <sys/socket.h>
70: #include <sys/protosw.h>
71: #include <sys/socketvar.h>
72: #include <sys/systm.h>
73: #include <sys/proc.h>
74:
75: #if ISFB31
76: #include <vm/vm_zone.h>
77: #endif
78:
79: #include <net/if.h>
80: #include <net/route.h>
81:
82: #include <netinet/in.h>
83: #include <netinet/in_systm.h>
84: #include <netinet/ip.h>
85: #include <netinet/in_pcb.h>
86: #include <netinet/in_var.h>
87: #include <netinet/ip_var.h>
88:
89: /*
90: * Divert sockets
91: */
92:
93: /*
94: * Allocate enough space to hold a full IP packet
95: */
96: #define DIVSNDQ (65536 + 100)
97: #define DIVRCVQ (65536 + 100)
98:
99: /* Global variables */
100:
101: /*
102: * ip_input() and ip_output() set this secret value before calling us to
103: * let us know which divert port to divert a packet to; this is done so
104: * we can use the existing prototype for struct protosw's pr_input().
105: * This is stored in host order.
106: */
107: u_short ip_divert_port;
108:
109: /*
110: * A 16 bit cookie is passed to the user process.
111: * The user process can send it back to help the caller know something
112: * about where the packet came from.
113: *
114: * If IPFW is the caller then the cookie is the rule that sent
115: * us here. On reinjection is is the rule after which processing
116: * should continue. Leaving it the same will make processing start
117: * at the rule number after that which sent it here. Setting it to
118: * 0 will restart processing at the beginning.
119: */
120: u_int16_t ip_divert_cookie;
121:
122: /* Internal variables */
123:
124: static struct inpcbhead divcb;
125: static struct inpcbinfo divcbinfo;
126:
127: static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
128: static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
129:
130: /* Optimization: have this preinitialized */
131: static struct sockaddr_in divsrc = { sizeof(divsrc), AF_INET };
132:
133: /* Internal functions */
134:
135: static int div_output(struct socket *so,
136: struct mbuf *m, struct sockaddr *addr, struct mbuf *control);
137:
138: /*
139: * Initialize divert connection block queue.
140: */
141: void
142: div_init(void)
143: {
144: LIST_INIT(&divcb);
145: divcbinfo.listhead = &divcb;
146: /*
147: * XXX We don't use the hash list for divert IP, but it's easier
148: * to allocate a one entry hash list than it is to check all
149: * over the place for hashbase == NULL.
150: */
151: divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
152: divcbinfo.porthashbase = hashinit(1, M_PCB, &divcbinfo.porthashmask);
153: divcbinfo.ipi_zone = (void *) zinit(sizeof(struct inpcb),(maxsockets * sizeof(struct inpcb)),
154: 4096, "divzone");
155:
156: /*
157: * ### LD 08/03: init IP forwarding at this point [ipfw is not a module yet]
158: */
159: ip_fw_init();
160: }
161:
162: /*
163: * Setup generic address and protocol structures
164: * for div_input routine, then pass them along with
165: * mbuf chain. ip->ip_len is assumed to have had
166: * the header length (hlen) subtracted out already.
167: * We tell whether the packet was incoming or outgoing
168: * by seeing if hlen == 0, which is a hack.
169: */
170: void
171: div_input(struct mbuf *m, int hlen)
172: {
173: struct ip *ip;
174: struct inpcb *inp;
175: struct socket *sa;
176:
177: /* Sanity check */
178: if (ip_divert_port == 0)
179: panic("div_input: port is 0");
180:
181: /* Assure header */
182: if (m->m_len < sizeof(struct ip) &&
183: (m = m_pullup(m, sizeof(struct ip))) == 0) {
184: return;
185: }
186: ip = mtod(m, struct ip *);
187:
188: /* Record divert cookie */
189: divsrc.sin_port = ip_divert_cookie;
190: ip_divert_cookie = 0;
191:
192: /* Restore packet header fields */
193: ip->ip_len += hlen;
194: HTONS(ip->ip_len);
195: HTONS(ip->ip_off);
196:
197: /*
198: * Record receive interface address, if any
199: * But only for incoming packets.
200: */
201: divsrc.sin_addr.s_addr = 0;
202: if (hlen) {
203: struct ifaddr *ifa;
204:
205: #if DIAGNOSTIC
206: /* Sanity check */
207: if (!(m->m_flags & M_PKTHDR))
208: panic("div_input: no pkt hdr");
209: #endif
210:
211: /* More fields affected by ip_input() */
212: HTONS(ip->ip_id);
213:
214: /* Find IP address for receive interface */
215: for (ifa = m->m_pkthdr.rcvif->if_addrhead.tqh_first;
216: ifa != NULL; ifa = ifa->ifa_link.tqe_next) {
217: if (ifa->ifa_addr == NULL)
218: continue;
219: if (ifa->ifa_addr->sa_family != AF_INET)
220: continue;
221: divsrc.sin_addr =
222: ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
223: break;
224: }
225: }
226: /*
227: * Record the incoming interface name whenever we have one.
228: */
229: bzero(&divsrc.sin_zero, sizeof(divsrc.sin_zero));
230: if (m->m_pkthdr.rcvif) {
231: /*
232: * Hide the actual interface name in there in the
233: * sin_zero array. XXX This needs to be moved to a
234: * different sockaddr type for divert, e.g.
235: * sockaddr_div with multiple fields like
236: * sockaddr_dl. Presently we have only 7 bytes
237: * but that will do for now as most interfaces
238: * are 4 or less + 2 or less bytes for unit.
239: * There is probably a faster way of doing this,
240: * possibly taking it from the sockaddr_dl on the iface.
241: * This solves the problem of a P2P link and a LAN interface
242: * having the same address, which can result in the wrong
243: * interface being assigned to the packet when fed back
244: * into the divert socket. Theoretically if the daemon saves
245: * and re-uses the sockaddr_in as suggested in the man pages,
246: * this iface name will come along for the ride.
247: * (see div_output for the other half of this.)
248: */
249: snprintf(divsrc.sin_zero, sizeof(divsrc.sin_zero),
250: "%s%d", m->m_pkthdr.rcvif->if_name,
251: m->m_pkthdr.rcvif->if_unit);
252: }
253:
254: /* Put packet on socket queue, if any */
255: sa = NULL;
256: for (inp = divcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
257: if (inp->inp_lport == htons(ip_divert_port))
258: sa = inp->inp_socket;
259: }
260: ip_divert_port = 0;
261: if (sa) {
262: if (sbappendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc,
263: m, (struct mbuf *)0) == 0)
264: m_freem(m);
265: else
266: sorwakeup(sa);
267: } else {
268: m_freem(m);
269: ipstat.ips_noproto++;
270: ipstat.ips_delivered--;
271: }
272: }
273:
274: /*
275: * Deliver packet back into the IP processing machinery.
276: *
277: * If no address specified, or address is 0.0.0.0, send to ip_output();
278: * otherwise, send to ip_input() and mark as having been received on
279: * the interface with that address.
280: */
281: static int
282: div_output(so, m, addr, control)
283: struct socket *so;
284: register struct mbuf *m;
285: struct sockaddr *addr;
286: struct mbuf *control;
287: {
288: register struct inpcb *const inp = sotoinpcb(so);
289: register struct ip *const ip = mtod(m, struct ip *);
290: struct sockaddr_in *sin = (struct sockaddr_in *)addr;
291: int error = 0;
292:
293: if (control)
294: m_freem(control); /* XXX */
295:
296: /* Loopback avoidance and state recovery */
297: if (sin) {
298: int len = 0;
299: char *c = sin->sin_zero;
300:
301: ip_divert_cookie = sin->sin_port;
302:
303: /*
304: * Find receive interface with the given name or IP address.
305: * The name is user supplied data so don't trust it's size or
306: * that it is zero terminated. The name has priority.
307: * We are presently assuming that the sockaddr_in
308: * has not been replaced by a sockaddr_div, so we limit it
309: * to 16 bytes in total. the name is stuffed (if it exists)
310: * in the sin_zero[] field.
311: */
312: while (*c++ && (len++ < sizeof(sin->sin_zero)));
313: if ((len > 0) && (len < sizeof(sin->sin_zero)))
314: m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
315: } else {
316: ip_divert_cookie = 0;
317: }
318:
319: /* Reinject packet into the system as incoming or outgoing */
320: if (!sin || sin->sin_addr.s_addr == 0) {
321: /*
322: * Don't allow both user specified and setsockopt options,
323: * and don't allow packet length sizes that will crash
324: */
325: if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) ||
326: ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
327: error = EINVAL;
328: goto cantsend;
329: }
330:
331: /* Convert fields to host order for ip_output() */
332: NTOHS(ip->ip_len);
333: NTOHS(ip->ip_off);
334:
335: /* Send packet to output processing */
336: ipstat.ips_rawout++; /* XXX */
337: error = ip_output(m, inp->inp_options, &inp->inp_route,
338: (so->so_options & SO_DONTROUTE) |
339: IP_ALLOWBROADCAST | IP_RAWOUTPUT, inp->inp_moptions);
340: } else {
341: struct ifaddr *ifa;
342:
343: /* If no luck with the name above. check by IP address. */
344: if (m->m_pkthdr.rcvif == NULL) {
345: /*
346: * Make sure there are no distractions
347: * for ifa_ifwithaddr. Clear the port and the ifname.
348: * Maybe zap all 8 bytes at once using a 64bit write?
349: */
350: bzero(sin->sin_zero, sizeof(sin->sin_zero));
351: /* *((u_int64_t *)sin->sin_zero) = 0; */ /* XXX ?? */
352: sin->sin_port = 0;
353: if (!(ifa = ifa_ifwithaddr((struct sockaddr *) sin))) {
354: error = EADDRNOTAVAIL;
355: goto cantsend;
356: }
357: m->m_pkthdr.rcvif = ifa->ifa_ifp;
358: }
359:
360: /* Send packet to input processing */
361: ip_input(m);
362: }
363:
364: /* paranoid: Reset for next time (and other packets) */
365: /* almost definitly already done in the ipfw filter but.. */
366: ip_divert_cookie = 0;
367: return error;
368:
369: cantsend:
370: ip_divert_cookie = 0;
371: m_freem(m);
372: return error;
373: }
374:
375: static int
376: div_attach(struct socket *so, int proto, struct proc *p)
377: {
378: struct inpcb *inp;
379: int error, s;
380:
381: inp = sotoinpcb(so);
382: if (inp)
383: panic("div_attach");
384: if (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
385: return error;
386:
387: s = splnet();
388: error = in_pcballoc(so, &divcbinfo, p);
389: splx(s);
390: if (error)
391: return error;
392: error = soreserve(so, div_sendspace, div_recvspace);
393: if (error)
394: return error;
395: inp = (struct inpcb *)so->so_pcb;
396: inp->inp_ip_p = proto;
397: inp->inp_flags |= INP_HDRINCL;
398: /* The socket is always "connected" because
399: we always know "where" to send the packet */
400: so->so_state |= SS_ISCONNECTED;
401: return 0;
402: }
403:
404: static int
405: div_detach(struct socket *so)
406: {
407: struct inpcb *inp;
408:
409: inp = sotoinpcb(so);
410: if (inp == 0)
411: panic("div_detach");
412: in_pcbdetach(inp);
413: return 0;
414: }
415:
416: static int
417: div_abort(struct socket *so)
418: {
419: soisdisconnected(so);
420: return div_detach(so);
421: }
422:
423: static int
424: div_disconnect(struct socket *so)
425: {
426: if ((so->so_state & SS_ISCONNECTED) == 0)
427: return ENOTCONN;
428: return div_abort(so);
429: }
430:
431: static int
432: div_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
433: {
434: struct inpcb *inp;
435: int s;
436: int error;
437:
438: s = splnet();
439: inp = sotoinpcb(so);
440: error = in_pcbbind(inp, nam, p);
441: splx(s);
442: return 0;
443: }
444:
445: static int
446: div_shutdown(struct socket *so)
447: {
448: socantsendmore(so);
449: return 0;
450: }
451:
452: static int
453: div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
454: struct mbuf *control, struct proc *p)
455: {
456: /* Packet must have a header (but that's about it) */
457: if (m->m_len < sizeof (struct ip) ||
458: (m = m_pullup(m, sizeof (struct ip))) == 0) {
459: ipstat.ips_toosmall++;
460: m_freem(m);
461: return EINVAL;
462: }
463:
464: /* Send packet */
465: return div_output(so, m, nam, control);
466: }
467:
468: struct pr_usrreqs div_usrreqs = {
469: div_abort, pru_accept_notsupp, div_attach, div_bind,
470: pru_connect_notsupp, pru_connect2_notsupp, in_control, div_detach,
471: div_disconnect, pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp,
472: pru_rcvoob_notsupp, div_send, pru_sense_null, div_shutdown,
473: in_setsockaddr, sosend, soreceive, sopoll
474: };
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