xref: /csrg-svn/sys/kern/uipc_usrreq.c (revision 17020)
1 /*	uipc_usrreq.c	6.9	84/08/27	*/
2 
3 #include "../h/param.h"
4 #include "../h/dir.h"
5 #include "../h/user.h"
6 #include "../h/mbuf.h"
7 #include "../h/domain.h"
8 #include "../h/protosw.h"
9 #include "../h/socket.h"
10 #include "../h/socketvar.h"
11 #include "../h/unpcb.h"
12 #include "../h/un.h"
13 #include "../h/inode.h"
14 #include "../h/file.h"
15 #include "../h/stat.h"
16 
17 /*
18  * Unix communications domain.
19  *
20  * TODO:
21  *	SEQPACKET, RDM
22  *	rethink name space problems
23  *	need a proper out-of-band
24  */
25 struct	sockaddr sun_noname = { AF_UNIX };
26 
27 /*ARGSUSED*/
28 uipc_usrreq(so, req, m, nam, rights)
29 	struct socket *so;
30 	int req;
31 	struct mbuf *m, *nam, *rights;
32 {
33 	struct unpcb *unp = sotounpcb(so);
34 	register struct socket *so2;
35 	int error = 0;
36 
37 	if (req != PRU_SEND && rights && rights->m_len) {
38 		error = EOPNOTSUPP;
39 		goto release;
40 	}
41 	if (unp == 0 && req != PRU_ATTACH) {
42 		error = EINVAL;
43 		goto release;
44 	}
45 	switch (req) {
46 
47 	case PRU_ATTACH:
48 		if (unp) {
49 			error = EISCONN;
50 			break;
51 		}
52 		error = unp_attach(so);
53 		break;
54 
55 	case PRU_DETACH:
56 		unp_detach(unp);
57 		break;
58 
59 	case PRU_BIND:
60 		error = unp_bind(unp, nam);
61 		break;
62 
63 	case PRU_LISTEN:
64 		if (unp->unp_inode == 0)
65 			error = EINVAL;
66 		break;
67 
68 	case PRU_CONNECT:
69 		error = unp_connect(so, nam);
70 		break;
71 
72 	case PRU_CONNECT2:
73 		error = unp_connect2(so, (struct mbuf *)0,
74 		    (struct socket *)nam);
75 		break;
76 
77 	case PRU_DISCONNECT:
78 		unp_disconnect(unp);
79 		break;
80 
81 	case PRU_ACCEPT:
82 		nam->m_len = unp->unp_remaddr->m_len;
83 		bcopy(mtod(unp->unp_remaddr, caddr_t),
84 		    mtod(nam, caddr_t), (unsigned)nam->m_len);
85 		break;
86 
87 	case PRU_SHUTDOWN:
88 		socantsendmore(so);
89 		unp_usrclosed(unp);
90 		break;
91 
92 	case PRU_RCVD:
93 		switch (so->so_type) {
94 
95 		case SOCK_DGRAM:
96 			panic("uipc 1");
97 			/*NOTREACHED*/
98 
99 		case SOCK_STREAM:
100 #define	rcv (&so->so_rcv)
101 #define snd (&so2->so_snd)
102 			if (unp->unp_conn == 0)
103 				break;
104 			so2 = unp->unp_conn->unp_socket;
105 			/*
106 			 * Transfer resources back to send port
107 			 * and wakeup any waiting to write.
108 			 */
109 			snd->sb_mbmax += rcv->sb_mbmax - rcv->sb_mbcnt;
110 			rcv->sb_mbmax = rcv->sb_mbcnt;
111 			snd->sb_hiwat += rcv->sb_hiwat - rcv->sb_cc;
112 			rcv->sb_hiwat = rcv->sb_cc;
113 			sbwakeup(snd);
114 #undef snd
115 #undef rcv
116 			break;
117 
118 		default:
119 			panic("uipc 2");
120 		}
121 		break;
122 
123 	case PRU_SEND:
124 		switch (so->so_type) {
125 
126 		case SOCK_DGRAM:
127 			if (nam) {
128 				if (unp->unp_conn) {
129 					error = EISCONN;
130 					break;
131 				}
132 				error = unp_connect(so, nam);
133 				if (error)
134 					break;
135 			} else {
136 				if (unp->unp_conn == 0) {
137 					error = ENOTCONN;
138 					break;
139 				}
140 			}
141 			so2 = unp->unp_conn->unp_socket;
142 			/* BEGIN XXX */
143 			if (rights) {
144 				error = unp_internalize(rights);
145 				if (error)
146 					break;
147 			}
148 			if (sbspace(&so2->so_rcv) > 0) {
149 				/*
150 				 * There's no record of source socket's
151 				 * name, so send null name for the moment.
152 				 */
153 				(void) sbappendaddr(&so2->so_rcv,
154 				    &sun_noname, m, rights);
155 				sbwakeup(&so2->so_rcv);
156 				m = 0;
157 			}
158 			/* END XXX */
159 			if (nam)
160 				unp_disconnect(unp);
161 			break;
162 
163 		case SOCK_STREAM:
164 #define	rcv (&so2->so_rcv)
165 #define	snd (&so->so_snd)
166 			if (rights && rights->m_len) {
167 				error = EOPNOTSUPP;
168 				break;
169 			}
170 			if (unp->unp_conn == 0)
171 				panic("uipc 3");
172 			so2 = unp->unp_conn->unp_socket;
173 			/*
174 			 * Send to paired receive port, and then
175 			 * give it enough resources to hold what it already has.
176 			 * Wake up readers.
177 			 */
178 			sbappend(rcv, m);
179 			snd->sb_mbmax -= rcv->sb_mbcnt - rcv->sb_mbmax;
180 			rcv->sb_mbmax = rcv->sb_mbcnt;
181 			snd->sb_hiwat -= rcv->sb_cc - rcv->sb_hiwat;
182 			rcv->sb_hiwat = rcv->sb_cc;
183 			sbwakeup(rcv);
184 #undef snd
185 #undef rcv
186 			break;
187 
188 		default:
189 			panic("uipc 4");
190 		}
191 		m = 0;
192 		break;
193 
194 	case PRU_ABORT:
195 		unp_drop(unp, ECONNABORTED);
196 		break;
197 
198 /* SOME AS YET UNIMPLEMENTED HOOKS */
199 	case PRU_CONTROL:
200 		return (EOPNOTSUPP);
201 
202 /* END UNIMPLEMENTED HOOKS */
203 	case PRU_SENSE:
204 		((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat;
205 		if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) {
206 			so2 = unp->unp_conn->unp_socket;
207 			((struct stat *) m)->st_blksize += so2->so_rcv.sb_cc;
208 		}
209 		return (0);
210 
211 	case PRU_RCVOOB:
212 		return (EOPNOTSUPP);
213 
214 	case PRU_SENDOOB:
215 		break;
216 
217 	case PRU_SOCKADDR:
218 		break;
219 
220 	case PRU_PEERADDR:
221 		break;
222 
223 	case PRU_SLOWTIMO:
224 		break;
225 
226 	default:
227 		panic("piusrreq");
228 	}
229 release:
230 	if (m)
231 		m_freem(m);
232 	return (error);
233 }
234 
235 /*
236  * We assign all buffering for stream sockets to the source,
237  * as that is where the flow control is implemented.
238  * Datagram sockets really use the sendspace as the maximum datagram size,
239  * and don't really want to reserve the sendspace.  Their recvspace should
240  * be large enough for at least one max-size datagram plus address.
241  */
242 #define	PIPSIZ	4096
243 int	unpst_sendspace = PIPSIZ;
244 int	unpst_recvspace = 0;
245 int	unpdg_sendspace = 2*1024;	/* really max datagram size */
246 int	unpdg_recvspace = 4*1024;
247 
248 unp_attach(so)
249 	struct socket *so;
250 {
251 	register struct mbuf *m;
252 	register struct unpcb *unp;
253 	int error;
254 
255 	switch (so->so_type) {
256 
257 	case SOCK_STREAM:
258 		error = soreserve(so, unpst_sendspace, unpst_recvspace);
259 		break;
260 
261 	case SOCK_DGRAM:
262 		error = soreserve(so, unpdg_sendspace, unpdg_recvspace);
263 		break;
264 	}
265 	if (error)
266 		return (error);
267 	m = m_getclr(M_DONTWAIT, MT_PCB);
268 	if (m == NULL)
269 		return (ENOBUFS);
270 	unp = mtod(m, struct unpcb *);
271 	so->so_pcb = (caddr_t)unp;
272 	unp->unp_socket = so;
273 	return (0);
274 }
275 
276 unp_detach(unp)
277 	register struct unpcb *unp;
278 {
279 
280 	if (unp->unp_inode) {
281 		unp->unp_inode->i_socket = 0;
282 		irele(unp->unp_inode);
283 		unp->unp_inode = 0;
284 	}
285 	if (unp->unp_conn)
286 		unp_disconnect(unp);
287 	while (unp->unp_refs)
288 		unp_drop(unp->unp_refs, ECONNRESET);
289 	soisdisconnected(unp->unp_socket);
290 	unp->unp_socket->so_pcb = 0;
291 	m_freem(unp->unp_remaddr);
292 	(void) m_free(dtom(unp));
293 }
294 
295 unp_bind(unp, nam)
296 	struct unpcb *unp;
297 	struct mbuf *nam;
298 {
299 	struct sockaddr_un *soun = mtod(nam, struct sockaddr_un *);
300 	register struct inode *ip;
301 	register struct nameidata *ndp = &u.u_nd;
302 	int error;
303 
304 	ndp->ni_dirp = soun->sun_path;
305 	if (nam->m_len == MLEN)
306 		return (EINVAL);
307 	*(mtod(nam, caddr_t) + nam->m_len) = 0;
308 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
309 	ndp->ni_nameiop = CREATE | FOLLOW;
310 	ndp->ni_segflg = UIO_SYSSPACE;
311 	ip = namei(ndp);
312 	if (ip) {
313 		iput(ip);
314 		return (EADDRINUSE);
315 	}
316 	if (error = u.u_error) {
317 		u.u_error = 0;			/* XXX */
318 		return (error);
319 	}
320 	ip = maknode(IFSOCK | 0777, ndp);
321 	if (ip == NULL) {
322 		error = u.u_error;		/* XXX */
323 		u.u_error = 0;			/* XXX */
324 		return (error);
325 	}
326 	ip->i_socket = unp->unp_socket;
327 	unp->unp_inode = ip;
328 	iunlock(ip);			/* but keep reference */
329 	return (0);
330 }
331 
332 unp_connect(so, nam)
333 	struct socket *so;
334 	struct mbuf *nam;
335 {
336 	register struct sockaddr_un *soun = mtod(nam, struct sockaddr_un *);
337 	register struct inode *ip;
338 	int error;
339 	register struct socket *so2;
340 	register struct nameidata *ndp = &u.u_nd;
341 
342 	ndp->ni_dirp = soun->sun_path;
343 	if (nam->m_len + (nam->m_off - MMINOFF) == MLEN)
344 		return (EMSGSIZE);
345 	*(mtod(nam, caddr_t) + nam->m_len) = 0;
346 	ndp->ni_nameiop = LOOKUP | FOLLOW;
347 	ndp->ni_segflg = UIO_SYSSPACE;
348 	ip = namei(ndp);
349 	if (ip == 0) {
350 		error = u.u_error;
351 		u.u_error = 0;
352 		return (error);		/* XXX */
353 	}
354 	if ((ip->i_mode&IFMT) != IFSOCK) {
355 		error = ENOTSOCK;
356 		goto bad;
357 	}
358 	so2 = ip->i_socket;
359 	if (so2 == 0) {
360 		error = ECONNREFUSED;
361 		goto bad;
362 	}
363 	if (so->so_type != so2->so_type) {
364 		error = EPROTOTYPE;
365 		goto bad;
366 	}
367 	if (so->so_proto->pr_flags & PR_CONNREQUIRED &&
368 	    ((so2->so_options&SO_ACCEPTCONN) == 0 ||
369 	     (so2 = sonewconn(so2)) == 0)) {
370 		error = ECONNREFUSED;
371 		goto bad;
372 	}
373 	error = unp_connect2(so, nam, so2);
374 bad:
375 	iput(ip);
376 	return (error);
377 }
378 
379 unp_connect2(so, sonam, so2)
380 	register struct socket *so;
381 	struct mbuf *sonam;
382 	register struct socket *so2;
383 {
384 	register struct unpcb *unp = sotounpcb(so);
385 	register struct unpcb *unp2;
386 
387 	if (so2->so_type != so->so_type)
388 		return (EPROTOTYPE);
389 	unp2 = sotounpcb(so2);
390 	unp->unp_conn = unp2;
391 	switch (so->so_type) {
392 
393 	case SOCK_DGRAM:
394 		unp->unp_nextref = unp2->unp_refs;
395 		unp2->unp_refs = unp;
396 		break;
397 
398 	case SOCK_STREAM:
399 		unp2->unp_conn = unp;
400 		if (sonam)
401 			unp2->unp_remaddr = m_copy(sonam, 0, (int)M_COPYALL);
402 		soisconnected(so2);
403 		soisconnected(so);
404 		break;
405 
406 	default:
407 		panic("unp_connect2");
408 	}
409 	return (0);
410 }
411 
412 unp_disconnect(unp)
413 	struct unpcb *unp;
414 {
415 	register struct unpcb *unp2 = unp->unp_conn;
416 
417 	if (unp2 == 0)
418 		return;
419 	unp->unp_conn = 0;
420 	switch (unp->unp_socket->so_type) {
421 
422 	case SOCK_DGRAM:
423 		if (unp2->unp_refs == unp)
424 			unp2->unp_refs = unp->unp_nextref;
425 		else {
426 			unp2 = unp2->unp_refs;
427 			for (;;) {
428 				if (unp2 == 0)
429 					panic("unp_disconnect");
430 				if (unp2->unp_nextref == unp)
431 					break;
432 				unp2 = unp2->unp_nextref;
433 			}
434 			unp2->unp_nextref = unp->unp_nextref;
435 		}
436 		unp->unp_nextref = 0;
437 		break;
438 
439 	case SOCK_STREAM:
440 		soisdisconnected(unp->unp_socket);
441 		unp2->unp_conn = 0;
442 		soisdisconnected(unp2->unp_socket);
443 		break;
444 	}
445 }
446 
447 #ifdef notdef
448 unp_abort(unp)
449 	struct unpcb *unp;
450 {
451 
452 	unp_detach(unp);
453 }
454 #endif
455 
456 /*ARGSUSED*/
457 unp_usrclosed(unp)
458 	struct unpcb *unp;
459 {
460 
461 }
462 
463 unp_drop(unp, errno)
464 	struct unpcb *unp;
465 	int errno;
466 {
467 	struct socket *so = unp->unp_socket;
468 
469 	so->so_error = errno;
470 	unp_disconnect(unp);
471 	if (so->so_head) {
472 		so->so_pcb = (caddr_t) 0;
473 		m_freem(unp->unp_remaddr);
474 		(void) m_free(dtom(unp));
475 		sofree(so);
476 	}
477 }
478 
479 #ifdef notdef
480 unp_drain()
481 {
482 
483 }
484 #endif
485 
486 unp_externalize(rights)
487 	struct mbuf *rights;
488 {
489 	int newfds = rights->m_len / sizeof (int);
490 	register int i;
491 	register struct file **rp = mtod(rights, struct file **);
492 	register struct file *fp;
493 	int f;
494 
495 	if (newfds > ufavail()) {
496 		for (i = 0; i < newfds; i++) {
497 			fp = *rp;
498 			unp_discard(fp);
499 			*rp++ = 0;
500 		}
501 		return (EMSGSIZE);
502 	}
503 	for (i = 0; i < newfds; i++) {
504 		f = ufalloc(0);
505 		if (f < 0)
506 			panic("unp_externalize");
507 		fp = *rp;
508 		u.u_ofile[f] = fp;
509 		fp->f_msgcount--;
510 		*(int *)rp++ = f;
511 	}
512 	return (0);
513 }
514 
515 unp_internalize(rights)
516 	struct mbuf *rights;
517 {
518 	register struct file **rp;
519 	int oldfds = rights->m_len / sizeof (int);
520 	register int i;
521 	register struct file *fp;
522 
523 	rp = mtod(rights, struct file **);
524 	for (i = 0; i < oldfds; i++)
525 		if (getf(*(int *)rp++) == 0)
526 			return (EBADF);
527 	rp = mtod(rights, struct file **);
528 	for (i = 0; i < oldfds; i++) {
529 		fp = getf(*(int *)rp);
530 		*rp++ = fp;
531 		fp->f_count++;
532 		fp->f_msgcount++;
533 	}
534 	return (0);
535 }
536 
537 int	unp_defer, unp_gcing;
538 int	unp_mark();
539 extern	struct domain unixdomain;
540 
541 unp_gc()
542 {
543 	register struct file *fp;
544 	register struct socket *so;
545 
546 	if (unp_gcing)
547 		return;
548 	unp_gcing = 1;
549 restart:
550 	unp_defer = 0;
551 	for (fp = file; fp < fileNFILE; fp++)
552 		fp->f_flag &= ~(FMARK|FDEFER);
553 	do {
554 		for (fp = file; fp < fileNFILE; fp++) {
555 			if (fp->f_count == 0)
556 				continue;
557 			if (fp->f_flag & FDEFER) {
558 				fp->f_flag &= ~FDEFER;
559 				unp_defer--;
560 			} else {
561 				if (fp->f_flag & FMARK)
562 					continue;
563 				if (fp->f_count == fp->f_msgcount)
564 					continue;
565 				fp->f_flag |= FMARK;
566 			}
567 			if (fp->f_type != DTYPE_SOCKET)
568 				continue;
569 			so = (struct socket *)fp->f_data;
570 			if (so->so_proto->pr_domain != &unixdomain ||
571 			    (so->so_proto->pr_flags&PR_ADDR) == 0)
572 				continue;
573 			if (so->so_rcv.sb_flags & SB_LOCK) {
574 				sbwait(&so->so_rcv);
575 				goto restart;
576 			}
577 			unp_scan(so->so_rcv.sb_mb, unp_mark);
578 		}
579 	} while (unp_defer);
580 	for (fp = file; fp < fileNFILE; fp++) {
581 		if (fp->f_count == 0)
582 			continue;
583 		if (fp->f_count == fp->f_msgcount && (fp->f_flag&FMARK)==0) {
584 			if (fp->f_type != DTYPE_SOCKET)
585 				panic("unp_gc");
586 			(void) soshutdown((struct socket *)fp->f_data, 0);
587 		}
588 	}
589 	unp_gcing = 0;
590 }
591 
592 unp_dispose(m)
593 	struct mbuf *m;
594 {
595 	int unp_discard();
596 
597 	if (m)
598 		unp_scan(m, unp_discard);
599 }
600 
601 unp_scan(m0, op)
602 	register struct mbuf *m0;
603 	int (*op)();
604 {
605 	register struct mbuf *m;
606 	register struct file **rp;
607 	register int i;
608 	int qfds;
609 
610 	while (m0) {
611 		for (m = m0; m; m = m->m_next)
612 			if (m->m_type == MT_RIGHTS && m->m_len) {
613 				qfds = m->m_len / sizeof (struct file *);
614 				rp = mtod(m, struct file **);
615 				for (i = 0; i < qfds; i++)
616 					(*op)(*rp++);
617 				break;		/* XXX, but saves time */
618 			}
619 		m0 = m0->m_act;
620 	}
621 }
622 
623 unp_mark(fp)
624 	struct file *fp;
625 {
626 
627 	if (fp->f_flag & FMARK)
628 		return;
629 	unp_defer++;
630 	fp->f_flag |= (FMARK|FDEFER);
631 }
632 
633 unp_discard(fp)
634 	struct file *fp;
635 {
636 
637 	fp->f_msgcount--;
638 	closef(fp);
639 }
640