xref: /netbsd-src/sys/netinet/udp_usrreq.c (revision 0b9f50897e9a9c6709320fafb4c3787fddcc0a45) 
1 /*
2  * Copyright (c) 1982, 1986, 1988, 1990 Regents of the University of California.
3  * 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  *	from: @(#)udp_usrreq.c	7.20 (Berkeley) 4/20/91
34  *	$Id: udp_usrreq.c,v 1.3 1993/05/22 11:42:52 cgd Exp $
35  */
36 
37 #include "param.h"
38 #include "malloc.h"
39 #include "mbuf.h"
40 #include "protosw.h"
41 #include "socket.h"
42 #include "socketvar.h"
43 #include "stat.h"
44 
45 #include "../net/if.h"
46 #include "../net/route.h"
47 
48 #include "in.h"
49 #include "in_systm.h"
50 #include "ip.h"
51 #include "in_pcb.h"
52 #include "ip_var.h"
53 #include "ip_icmp.h"
54 #include "udp.h"
55 #include "udp_var.h"
56 
57 struct	inpcb *udp_last_inpcb = &udb;
58 
59 /*
60  * UDP protocol implementation.
61  * Per RFC 768, August, 1980.
62  */
63 udp_init()
64 {
65 
66 	udb.inp_next = udb.inp_prev = &udb;
67 }
68 
69 #ifndef	COMPAT_42
70 int	udpcksum = 1;
71 #else
72 int	udpcksum = 0;		/* XXX */
73 #endif
74 int	udp_ttl = UDP_TTL;
75 
76 struct	sockaddr_in udp_in = { sizeof(udp_in), AF_INET };
77 
78 udp_input(m, iphlen)
79 	register struct mbuf *m;
80 	int iphlen;
81 {
82 	register struct ip *ip;
83 	register struct udphdr *uh;
84 	register struct inpcb *inp;
85 	struct mbuf *opts = 0;
86 	int len;
87 	struct ip save_ip;
88 
89 	udpstat.udps_ipackets++;
90 
91 	/*
92 	 * Strip IP options, if any; should skip this,
93 	 * make available to user, and use on returned packets,
94 	 * but we don't yet have a way to check the checksum
95 	 * with options still present.
96 	 */
97 	if (iphlen > sizeof (struct ip)) {
98 		ip_stripoptions(m, (struct mbuf *)0);
99 		iphlen = sizeof(struct ip);
100 	}
101 
102 	/*
103 	 * Get IP and UDP header together in first mbuf.
104 	 */
105 	ip = mtod(m, struct ip *);
106 	if (m->m_len < iphlen + sizeof(struct udphdr)) {
107 		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
108 			udpstat.udps_hdrops++;
109 			return;
110 		}
111 		ip = mtod(m, struct ip *);
112 	}
113 	uh = (struct udphdr *)((caddr_t)ip + iphlen);
114 
115 	/*
116 	 * Make mbuf data length reflect UDP length.
117 	 * If not enough data to reflect UDP length, drop.
118 	 */
119 	len = ntohs((u_short)uh->uh_ulen);
120 	if (ip->ip_len != len) {
121 		if (len > ip->ip_len) {
122 			udpstat.udps_badlen++;
123 			goto bad;
124 		}
125 		m_adj(m, len - ip->ip_len);
126 		/* ip->ip_len = len; */
127 	}
128 	/*
129 	 * Save a copy of the IP header in case we want restore it
130 	 * for sending an ICMP error message in response.
131 	 */
132 	save_ip = *ip;
133 
134 	/*
135 	 * Checksum extended UDP header and data.
136 	 */
137 	if (udpcksum && uh->uh_sum) {
138 		((struct ipovly *)ip)->ih_next = 0;
139 		((struct ipovly *)ip)->ih_prev = 0;
140 		((struct ipovly *)ip)->ih_x1 = 0;
141 		((struct ipovly *)ip)->ih_len = uh->uh_ulen;
142 		if (uh->uh_sum = in_cksum(m, len + sizeof (struct ip))) {
143 			udpstat.udps_badsum++;
144 			m_freem(m);
145 			return;
146 		}
147 	}
148 
149 	/*
150 	 * Locate pcb for datagram.
151 	 */
152 	inp = udp_last_inpcb;
153 	if (inp->inp_lport != uh->uh_dport ||
154 	    inp->inp_fport != uh->uh_sport ||
155 	    inp->inp_faddr.s_addr != ip->ip_src.s_addr ||
156 	    inp->inp_laddr.s_addr != ip->ip_dst.s_addr) {
157 		inp = in_pcblookup(&udb, ip->ip_src, uh->uh_sport,
158 		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD);
159 		if (inp)
160 			udp_last_inpcb = inp;
161 		udpstat.udpps_pcbcachemiss++;
162 	}
163 	if (inp == 0) {
164 		/* don't send ICMP response for broadcast packet */
165 		udpstat.udps_noport++;
166 		if (m->m_flags & M_BCAST) {
167 			udpstat.udps_noportbcast++;
168 			goto bad;
169 		}
170 		*ip = save_ip;
171 		ip->ip_len += iphlen;
172 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT);
173 		return;
174 	}
175 
176 	/*
177 	 * Construct sockaddr format source address.
178 	 * Stuff source address and datagram in user buffer.
179 	 */
180 	udp_in.sin_port = uh->uh_sport;
181 	udp_in.sin_addr = ip->ip_src;
182 	if (inp->inp_flags & INP_CONTROLOPTS) {
183 		struct mbuf **mp = &opts;
184 		struct mbuf *udp_saveopt();
185 
186 		if (inp->inp_flags & INP_RECVDSTADDR) {
187 			*mp = udp_saveopt((caddr_t) &ip->ip_dst,
188 			    sizeof(struct in_addr), IP_RECVDSTADDR);
189 			if (*mp)
190 				mp = &(*mp)->m_next;
191 		}
192 #ifdef notyet
193 		/* options were tossed above */
194 		if (inp->inp_flags & INP_RECVOPTS) {
195 			*mp = udp_saveopt((caddr_t) opts_deleted_above,
196 			    sizeof(struct in_addr), IP_RECVOPTS);
197 			if (*mp)
198 				mp = &(*mp)->m_next;
199 		}
200 		/* ip_srcroute doesn't do what we want here, need to fix */
201 		if (inp->inp_flags & INP_RECVRETOPTS) {
202 			*mp = udp_saveopt((caddr_t) ip_srcroute(),
203 			    sizeof(struct in_addr), IP_RECVRETOPTS);
204 			if (*mp)
205 				mp = &(*mp)->m_next;
206 		}
207 #endif
208 	}
209 	iphlen += sizeof(struct udphdr);
210 	m->m_len -= iphlen;
211 	m->m_pkthdr.len -= iphlen;
212 	m->m_data += iphlen;
213 	if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in,
214 	    m, opts) == 0) {
215 		udpstat.udps_fullsock++;
216 		goto bad;
217 	}
218 	sorwakeup(inp->inp_socket);
219 	return;
220 bad:
221 	m_freem(m);
222 	if (opts)
223 		m_freem(opts);
224 }
225 
226 /*
227  * Create a "control" mbuf containing the specified data
228  * with the specified type for presentation with a datagram.
229  */
230 struct mbuf *
231 udp_saveopt(p, size, type)
232 	caddr_t p;
233 	register int size;
234 	int type;
235 {
236 	register struct cmsghdr *cp;
237 	struct mbuf *m;
238 
239 	if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL)
240 		return ((struct mbuf *) NULL);
241 	cp = (struct cmsghdr *) mtod(m, struct cmsghdr *);
242 	bcopy(p, (caddr_t)(cp + 1), size);
243 	size += sizeof(*cp);
244 	m->m_len = size;
245 	cp->cmsg_len = size;
246 	cp->cmsg_level = IPPROTO_IP;
247 	cp->cmsg_type = type;
248 	return (m);
249 }
250 
251 /*
252  * Notify a udp user of an asynchronous error;
253  * just wake up so that he can collect error status.
254  */
255 udp_notify(inp, errno)
256 	register struct inpcb *inp;
257 {
258 
259 	inp->inp_socket->so_error = errno;
260 	sorwakeup(inp->inp_socket);
261 	sowwakeup(inp->inp_socket);
262 }
263 
264 udp_ctlinput(cmd, sa, ip)
265 	int cmd;
266 	struct sockaddr *sa;
267 	register struct ip *ip;
268 {
269 	register struct udphdr *uh;
270 	extern struct in_addr zeroin_addr;
271 	extern u_char inetctlerrmap[];
272 
273 	if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0)
274 		return;
275 	if (ip) {
276 		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
277 		in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport,
278 			cmd, udp_notify);
279 	} else
280 		in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify);
281 }
282 
283 udp_output(inp, m, addr, control)
284 	register struct inpcb *inp;
285 	register struct mbuf *m;
286 	struct mbuf *addr, *control;
287 {
288 	register struct udpiphdr *ui;
289 	register int len = m->m_pkthdr.len;
290 	struct in_addr laddr;
291 	int s, error = 0;
292 
293 	if (control)
294 		m_freem(control);		/* XXX */
295 
296 	if (addr) {
297 		laddr = inp->inp_laddr;
298 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
299 			error = EISCONN;
300 			goto release;
301 		}
302 		/*
303 		 * Must block input while temporarily connected.
304 		 */
305 		s = splnet();
306 		error = in_pcbconnect(inp, addr);
307 		if (error) {
308 			splx(s);
309 			goto release;
310 		}
311 	} else {
312 		if (inp->inp_faddr.s_addr == INADDR_ANY) {
313 			error = ENOTCONN;
314 			goto release;
315 		}
316 	}
317 	/*
318 	 * Calculate data length and get a mbuf
319 	 * for UDP and IP headers.
320 	 */
321 	M_PREPEND(m, sizeof(struct udpiphdr), M_WAIT);
322 
323 	/*
324 	 * Fill in mbuf with extended UDP header
325 	 * and addresses and length put into network format.
326 	 */
327 	ui = mtod(m, struct udpiphdr *);
328 	ui->ui_next = ui->ui_prev = 0;
329 	ui->ui_x1 = 0;
330 	ui->ui_pr = IPPROTO_UDP;
331 	ui->ui_len = htons((u_short)len + sizeof (struct udphdr));
332 	ui->ui_src = inp->inp_laddr;
333 	ui->ui_dst = inp->inp_faddr;
334 	ui->ui_sport = inp->inp_lport;
335 	ui->ui_dport = inp->inp_fport;
336 	ui->ui_ulen = ui->ui_len;
337 
338 	/*
339 	 * Stuff checksum and output datagram.
340 	 */
341 	ui->ui_sum = 0;
342 	if (udpcksum) {
343 	    if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0)
344 		ui->ui_sum = 0xffff;
345 	}
346 	((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
347 	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;	/* XXX */
348 	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;	/* XXX */
349 	udpstat.udps_opackets++;
350 	error = ip_output(m, inp->inp_options, &inp->inp_route,
351 	    inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST));
352 
353 	if (addr) {
354 		in_pcbdisconnect(inp);
355 		inp->inp_laddr = laddr;
356 		splx(s);
357 	}
358 	return (error);
359 
360 release:
361 	m_freem(m);
362 	return (error);
363 }
364 
365 u_long	udp_sendspace = 9216;		/* really max datagram size */
366 u_long	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
367 					/* 40 1K datagrams */
368 
369 /*ARGSUSED*/
370 udp_usrreq(so, req, m, addr, control)
371 	struct socket *so;
372 	int req;
373 	struct mbuf *m, *addr, *control;
374 {
375 	struct inpcb *inp = sotoinpcb(so);
376 	int error = 0;
377 	int s;
378 
379 	if (req == PRU_CONTROL)
380 		return (in_control(so, (int)m, (caddr_t)addr,
381 			(struct ifnet *)control));
382 	if (inp == NULL && req != PRU_ATTACH) {
383 		error = EINVAL;
384 		goto release;
385 	}
386 	/*
387 	 * Note: need to block udp_input while changing
388 	 * the udp pcb queue and/or pcb addresses.
389 	 */
390 	switch (req) {
391 
392 	case PRU_ATTACH:
393 		if (inp != NULL) {
394 			error = EINVAL;
395 			break;
396 		}
397 		s = splnet();
398 		error = in_pcballoc(so, &udb);
399 		splx(s);
400 		if (error)
401 			break;
402 		error = soreserve(so, udp_sendspace, udp_recvspace);
403 		if (error)
404 			break;
405 		((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = udp_ttl;
406 		break;
407 
408 	case PRU_DETACH:
409 		udp_detach(inp);
410 		break;
411 
412 	case PRU_BIND:
413 		s = splnet();
414 		error = in_pcbbind(inp, addr);
415 		splx(s);
416 		break;
417 
418 	case PRU_LISTEN:
419 		error = EOPNOTSUPP;
420 		break;
421 
422 	case PRU_CONNECT:
423 		if (inp->inp_faddr.s_addr != INADDR_ANY) {
424 			error = EISCONN;
425 			break;
426 		}
427 		s = splnet();
428 		error = in_pcbconnect(inp, addr);
429 		splx(s);
430 		if (error == 0)
431 			soisconnected(so);
432 		break;
433 
434 	case PRU_CONNECT2:
435 		error = EOPNOTSUPP;
436 		break;
437 
438 	case PRU_ACCEPT:
439 		error = EOPNOTSUPP;
440 		break;
441 
442 	case PRU_DISCONNECT:
443 		if (inp->inp_faddr.s_addr == INADDR_ANY) {
444 			error = ENOTCONN;
445 			break;
446 		}
447 		s = splnet();
448 		in_pcbdisconnect(inp);
449 		inp->inp_laddr.s_addr = INADDR_ANY;
450 		splx(s);
451 		so->so_state &= ~SS_ISCONNECTED;		/* XXX */
452 		break;
453 
454 	case PRU_SHUTDOWN:
455 		socantsendmore(so);
456 		break;
457 
458 	case PRU_SEND:
459 		return (udp_output(inp, m, addr, control));
460 
461 	case PRU_ABORT:
462 		soisdisconnected(so);
463 		udp_detach(inp);
464 		break;
465 
466 	case PRU_SOCKADDR:
467 		in_setsockaddr(inp, addr);
468 		break;
469 
470 	case PRU_PEERADDR:
471 		in_setpeeraddr(inp, addr);
472 		break;
473 
474 	case PRU_SENSE:
475 		/*
476 		 * stat: don't bother with a blocksize.
477 		 */
478 		return (0);
479 
480 	case PRU_SENDOOB:
481 	case PRU_FASTTIMO:
482 	case PRU_SLOWTIMO:
483 	case PRU_PROTORCV:
484 	case PRU_PROTOSEND:
485 		error =  EOPNOTSUPP;
486 		break;
487 
488 	case PRU_RCVD:
489 	case PRU_RCVOOB:
490 		return (EOPNOTSUPP);	/* do not free mbuf's */
491 
492 	default:
493 		panic("udp_usrreq");
494 	}
495 
496 release:
497 	if (control) {
498 		printf("udp control data unexpectedly retained\n");
499 		m_freem(control);
500 	}
501 	if (m)
502 		m_freem(m);
503 	return (error);
504 }
505 
506 udp_detach(inp)
507 	struct inpcb *inp;
508 {
509 	int s = splnet();
510 
511 	if (inp == udp_last_inpcb)
512 		udp_last_inpcb = &udb;
513 	in_pcbdetach(inp);
514 	splx(s);
515 }
516