xref: /freebsd/sys/netinet/raw_ip.c (revision 0de89efe5c443f213c7ea28773ef2dc6cf3af2ed)
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  *	@(#)raw_ip.c	8.7 (Berkeley) 5/15/95
34  *	$Id: raw_ip.c,v 1.48 1997/08/16 19:15:37 wollman Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/proc.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/sysctl.h>
47 
48 #include <net/if.h>
49 #include <net/route.h>
50 
51 #define _IP_VHL
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #include <netinet/in_pcb.h>
56 #include <netinet/in_var.h>
57 #include <netinet/ip_var.h>
58 #include <netinet/ip_mroute.h>
59 
60 #include <netinet/ip_fw.h>
61 
62 #if !defined(COMPAT_IPFW) || COMPAT_IPFW == 1
63 #undef COMPAT_IPFW
64 #define COMPAT_IPFW 1
65 #else
66 #undef COMPAT_IPFW
67 #endif
68 
69 static struct inpcbhead ripcb;
70 static struct inpcbinfo ripcbinfo;
71 
72 /*
73  * Nominal space allocated to a raw ip socket.
74  */
75 #define	RIPSNDQ		8192
76 #define	RIPRCVQ		8192
77 
78 /*
79  * Raw interface to IP protocol.
80  */
81 
82 /*
83  * Initialize raw connection block q.
84  */
85 void
86 rip_init()
87 {
88 	LIST_INIT(&ripcb);
89 	ripcbinfo.listhead = &ripcb;
90 	/*
91 	 * XXX We don't use the hash list for raw IP, but it's easier
92 	 * to allocate a one entry hash list than it is to check all
93 	 * over the place for hashbase == NULL.
94 	 */
95 	ripcbinfo.hashbase = hashinit(1, M_PCB, &ripcbinfo.hashmask);
96 }
97 
98 static struct	sockaddr_in ripsrc = { sizeof(ripsrc), AF_INET };
99 /*
100  * Setup generic address and protocol structures
101  * for raw_input routine, then pass them along with
102  * mbuf chain.
103  */
104 void
105 rip_input(m, iphlen)
106 	struct mbuf *m;
107 	int iphlen;
108 {
109 	register struct ip *ip = mtod(m, struct ip *);
110 	register struct inpcb *inp;
111 	struct inpcb *last = 0;
112 	struct mbuf *opts = 0;
113 
114 	ripsrc.sin_addr = ip->ip_src;
115 	for (inp = ripcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
116 		if (inp->inp_ip_p && inp->inp_ip_p != ip->ip_p)
117 			continue;
118 		if (inp->inp_laddr.s_addr &&
119                   inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
120 			continue;
121 		if (inp->inp_faddr.s_addr &&
122                   inp->inp_faddr.s_addr != ip->ip_src.s_addr)
123 			continue;
124 		if (last) {
125 			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);
126 			if (n) {
127 				if (last->inp_flags & INP_CONTROLOPTS ||
128 				    last->inp_socket->so_options & SO_TIMESTAMP)
129 				    ip_savecontrol(last, &opts, ip, n);
130 				if (sbappendaddr(&last->inp_socket->so_rcv,
131 				    (struct sockaddr *)&ripsrc, n,
132 				    opts) == 0) {
133 					/* should notify about lost packet */
134 					m_freem(n);
135 					if (opts)
136 					    m_freem(opts);
137 				} else
138 					sorwakeup(last->inp_socket);
139 				opts = 0;
140 			}
141 		}
142 		last = inp;
143 	}
144 	if (last) {
145 		if (last->inp_flags & INP_CONTROLOPTS ||
146 		    last->inp_socket->so_options & SO_TIMESTAMP)
147 			ip_savecontrol(last, &opts, ip, m);
148 		if (sbappendaddr(&last->inp_socket->so_rcv,
149 		    (struct sockaddr *)&ripsrc, m, opts) == 0) {
150 			m_freem(m);
151 			if (opts)
152 			    m_freem(opts);
153 		} else
154 			sorwakeup(last->inp_socket);
155 	} else {
156 		m_freem(m);
157               ipstat.ips_noproto++;
158               ipstat.ips_delivered--;
159       }
160 }
161 
162 /*
163  * Generate IP header and pass packet to ip_output.
164  * Tack on options user may have setup with control call.
165  */
166 int
167 rip_output(m, so, dst)
168 	register struct mbuf *m;
169 	struct socket *so;
170 	u_long dst;
171 {
172 	register struct ip *ip;
173 	register struct inpcb *inp = sotoinpcb(so);
174 	int flags = (so->so_options & SO_DONTROUTE) | IP_ALLOWBROADCAST;
175 
176 	/*
177 	 * If the user handed us a complete IP packet, use it.
178 	 * Otherwise, allocate an mbuf for a header and fill it in.
179 	 */
180 	if ((inp->inp_flags & INP_HDRINCL) == 0) {
181 		if (m->m_pkthdr.len + sizeof(struct ip) > IP_MAXPACKET) {
182 			m_freem(m);
183 			return(EMSGSIZE);
184 		}
185 		M_PREPEND(m, sizeof(struct ip), M_WAIT);
186 		ip = mtod(m, struct ip *);
187 		ip->ip_tos = 0;
188 		ip->ip_off = 0;
189 		ip->ip_p = inp->inp_ip_p;
190 		ip->ip_len = m->m_pkthdr.len;
191 		ip->ip_src = inp->inp_laddr;
192 		ip->ip_dst.s_addr = dst;
193 		ip->ip_ttl = MAXTTL;
194 	} else {
195 		if (m->m_pkthdr.len > IP_MAXPACKET) {
196 			m_freem(m);
197 			return(EMSGSIZE);
198 		}
199 		ip = mtod(m, struct ip *);
200 		/* don't allow both user specified and setsockopt options,
201 		   and don't allow packet length sizes that will crash */
202 		if (((IP_VHL_HL(ip->ip_vhl) != (sizeof (*ip) >> 2))
203 		     && inp->inp_options)
204 		    || (ip->ip_len > m->m_pkthdr.len)
205 		    || (ip->ip_len < (IP_VHL_HL(ip->ip_vhl) << 2))) {
206 			m_freem(m);
207 			return EINVAL;
208 		}
209 		if (ip->ip_id == 0)
210 			ip->ip_id = htons(ip_id++);
211 		/* XXX prevent ip_output from overwriting header fields */
212 		flags |= IP_RAWOUTPUT;
213 		ipstat.ips_rawout++;
214 	}
215 	return (ip_output(m, inp->inp_options, &inp->inp_route, flags,
216 			  inp->inp_moptions));
217 }
218 
219 /*
220  * Raw IP socket option processing.
221  */
222 int
223 rip_ctloutput(op, so, level, optname, m, p)
224 	int op;
225 	struct socket *so;
226 	int level, optname;
227 	struct mbuf **m;
228 	struct proc *p;
229 {
230 	register struct inpcb *inp = sotoinpcb(so);
231 	register int error;
232 
233 	if (level != IPPROTO_IP) {
234 		if (op == PRCO_SETOPT && *m)
235 			(void)m_free(*m);
236 		return (EINVAL);
237 	}
238 
239 	switch (optname) {
240 
241 	case IP_HDRINCL:
242 		error = 0;
243 		if (op == PRCO_SETOPT) {
244 			if (m == 0 || *m == 0 || (*m)->m_len < sizeof (int))
245 				error = EINVAL;
246 			else if (*mtod(*m, int *))
247 				inp->inp_flags |= INP_HDRINCL;
248 			else
249 				inp->inp_flags &= ~INP_HDRINCL;
250 			if (*m)
251 				(void)m_free(*m);
252 		} else {
253 			*m = m_get(M_WAIT, MT_SOOPTS);
254 			(*m)->m_len = sizeof (int);
255 			*mtod(*m, int *) = inp->inp_flags & INP_HDRINCL;
256 		}
257 		return (error);
258 
259 #ifdef COMPAT_IPFW
260 	case IP_FW_GET:
261 		if (ip_fw_ctl_ptr == NULL || op == PRCO_SETOPT) {
262 			if (*m) (void)m_free(*m);
263 			return(EINVAL);
264 		}
265 		return (*ip_fw_ctl_ptr)(optname, m);
266 
267 	case IP_FW_ADD:
268 	case IP_FW_DEL:
269 	case IP_FW_FLUSH:
270 	case IP_FW_ZERO:
271 		if (ip_fw_ctl_ptr == NULL || op != PRCO_SETOPT) {
272 			if (*m) (void)m_free(*m);
273 			return(EINVAL);
274 		}
275 		return (*ip_fw_ctl_ptr)(optname, m);
276 
277 	case IP_NAT:
278 		if (ip_nat_ctl_ptr == NULL) {
279 			if (*m) (void)m_free(*m);
280 			return(EINVAL);
281 		}
282 		return (*ip_nat_ctl_ptr)(op, m);
283 
284 #endif
285 	case IP_RSVP_ON:
286 		return ip_rsvp_init(so);
287 		break;
288 
289 	case IP_RSVP_OFF:
290 		return ip_rsvp_done();
291 		break;
292 
293 	case IP_RSVP_VIF_ON:
294 		return ip_rsvp_vif_init(so, *m);
295 
296 	case IP_RSVP_VIF_OFF:
297 		return ip_rsvp_vif_done(so, *m);
298 
299 	case MRT_INIT:
300 	case MRT_DONE:
301 	case MRT_ADD_VIF:
302 	case MRT_DEL_VIF:
303 	case MRT_ADD_MFC:
304 	case MRT_DEL_MFC:
305 	case MRT_VERSION:
306 	case MRT_ASSERT:
307 		if (op == PRCO_SETOPT) {
308 			error = ip_mrouter_set(optname, so, *m);
309 			if (*m)
310 				(void)m_free(*m);
311 		} else if (op == PRCO_GETOPT) {
312 			error = ip_mrouter_get(optname, so, m);
313 		} else
314 			error = EINVAL;
315 		return (error);
316 	}
317 	return (ip_ctloutput(op, so, level, optname, m, p));
318 }
319 
320 /*
321  * This function exists solely to receive the PRC_IFDOWN messages which
322  * are sent by if_down().  It looks for an ifaddr whose ifa_addr is sa,
323  * and calls in_ifadown() to remove all routes corresponding to that address.
324  * It also receives the PRC_IFUP messages from if_up() and reinstalls the
325  * interface routes.
326  */
327 void
328 rip_ctlinput(cmd, sa, vip)
329 	int cmd;
330 	struct sockaddr *sa;
331 	void *vip;
332 {
333 	struct in_ifaddr *ia;
334 	struct ifnet *ifp;
335 	int err;
336 	int flags;
337 
338 	switch(cmd) {
339 	case PRC_IFDOWN:
340 		for (ia = in_ifaddrhead.tqh_first; ia;
341 		     ia = ia->ia_link.tqe_next) {
342 			if (ia->ia_ifa.ifa_addr == sa
343 			    && (ia->ia_flags & IFA_ROUTE)) {
344 				/*
345 				 * in_ifscrub kills the interface route.
346 				 */
347 				in_ifscrub(ia->ia_ifp, ia);
348 				/*
349 				 * in_ifadown gets rid of all the rest of
350 				 * the routes.  This is not quite the right
351 				 * thing to do, but at least if we are running
352 				 * a routing process they will come back.
353 				 */
354 				in_ifadown(&ia->ia_ifa);
355 				break;
356 			}
357 		}
358 		break;
359 
360 	case PRC_IFUP:
361 		for (ia = in_ifaddrhead.tqh_first; ia;
362 		     ia = ia->ia_link.tqe_next) {
363 			if (ia->ia_ifa.ifa_addr == sa)
364 				break;
365 		}
366 		if (ia == 0 || (ia->ia_flags & IFA_ROUTE))
367 			return;
368 		flags = RTF_UP;
369 		ifp = ia->ia_ifa.ifa_ifp;
370 
371 		if ((ifp->if_flags & IFF_LOOPBACK)
372 		    || (ifp->if_flags & IFF_POINTOPOINT))
373 			flags |= RTF_HOST;
374 
375 		err = rtinit(&ia->ia_ifa, RTM_ADD, flags);
376 		if (err == 0)
377 			ia->ia_flags |= IFA_ROUTE;
378 		break;
379 	}
380 }
381 
382 static u_long	rip_sendspace = RIPSNDQ;
383 static u_long	rip_recvspace = RIPRCVQ;
384 
385 SYSCTL_INT(_net_inet_raw, OID_AUTO, maxdgram, CTLFLAG_RW, &rip_sendspace,
386 	   0, "");
387 SYSCTL_INT(_net_inet_raw, OID_AUTO, recvspace, CTLFLAG_RW, &rip_recvspace,
388 	   0, "");
389 
390 static int
391 rip_attach(struct socket *so, int proto, struct proc *p)
392 {
393 	struct inpcb *inp;
394 	int error;
395 
396 	inp = sotoinpcb(so);
397 	if (inp)
398 		panic("rip_attach");
399 	if (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
400 		return error;
401 
402 	if ((error = soreserve(so, rip_sendspace, rip_recvspace)) ||
403 	    (error = in_pcballoc(so, &ripcbinfo, p)))
404 		return error;
405 	inp = (struct inpcb *)so->so_pcb;
406 	inp->inp_ip_p = proto;
407 	return 0;
408 }
409 
410 static int
411 rip_detach(struct socket *so)
412 {
413 	struct inpcb *inp;
414 
415 	inp = sotoinpcb(so);
416 	if (inp == 0)
417 		panic("rip_detach");
418 	if (so == ip_mrouter)
419 		ip_mrouter_done();
420 	ip_rsvp_force_done(so);
421 	if (so == ip_rsvpd)
422 		ip_rsvp_done();
423 	in_pcbdetach(inp);
424 	return 0;
425 }
426 
427 static int
428 rip_abort(struct socket *so)
429 {
430 	soisdisconnected(so);
431 	return rip_detach(so);
432 }
433 
434 static int
435 rip_disconnect(struct socket *so)
436 {
437 	if ((so->so_state & SS_ISCONNECTED) == 0)
438 		return ENOTCONN;
439 	return rip_abort(so);
440 }
441 
442 static int
443 rip_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
444 {
445 	struct inpcb *inp = sotoinpcb(so);
446 	struct sockaddr_in *addr = (struct sockaddr_in *)nam;
447 
448 	if (nam->sa_len != sizeof(*addr))
449 		return EINVAL;
450 
451 	if (TAILQ_EMPTY(&ifnet) || ((addr->sin_family != AF_INET) &&
452 				    (addr->sin_family != AF_IMPLINK)) ||
453 	    (addr->sin_addr.s_addr &&
454 	     ifa_ifwithaddr((struct sockaddr *)addr) == 0))
455 		return EADDRNOTAVAIL;
456 	inp->inp_laddr = addr->sin_addr;
457 	return 0;
458 }
459 
460 static int
461 rip_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
462 {
463 	struct inpcb *inp = sotoinpcb(so);
464 	struct sockaddr_in *addr = (struct sockaddr_in *)nam;
465 
466 	if (nam->sa_len != sizeof(*addr))
467 		return EINVAL;
468 	if (TAILQ_EMPTY(&ifnet))
469 		return EADDRNOTAVAIL;
470 	if ((addr->sin_family != AF_INET) &&
471 	    (addr->sin_family != AF_IMPLINK))
472 		return EAFNOSUPPORT;
473 	inp->inp_faddr = addr->sin_addr;
474 	soisconnected(so);
475 	return 0;
476 }
477 
478 static int
479 rip_shutdown(struct socket *so)
480 {
481 	socantsendmore(so);
482 	return 0;
483 }
484 
485 static int
486 rip_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
487 	 struct mbuf *control, struct proc *p)
488 {
489 	struct inpcb *inp = sotoinpcb(so);
490 	register u_long dst;
491 
492 	if (so->so_state & SS_ISCONNECTED) {
493 		if (nam) {
494 			m_freem(m);
495 			return EISCONN;
496 		}
497 		dst = inp->inp_faddr.s_addr;
498 	} else {
499 		if (nam == NULL) {
500 			m_freem(m);
501 			return ENOTCONN;
502 		}
503 		dst = ((struct sockaddr_in *)nam)->sin_addr.s_addr;
504 	}
505 	return rip_output(m, so, dst);
506 }
507 
508 struct pr_usrreqs rip_usrreqs = {
509 	rip_abort, pru_accept_notsupp, rip_attach, rip_bind, rip_connect,
510 	pru_connect2_notsupp, in_control, rip_detach, rip_disconnect,
511 	pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp,
512 	pru_rcvoob_notsupp, rip_send, pru_sense_null, rip_shutdown,
513 	in_setsockaddr, sosend, soreceive, sopoll
514 };
515