xref: /csrg-svn/sys/kern/uipc_socket.c (revision 12757)
1 /*	uipc_socket.c	4.75	83/05/27	*/
2 
3 #include "../h/param.h"
4 #include "../h/systm.h"
5 #include "../h/dir.h"
6 #include "../h/user.h"
7 #include "../h/proc.h"
8 #include "../h/file.h"
9 #include "../h/inode.h"
10 #include "../h/buf.h"
11 #include "../h/mbuf.h"
12 #include "../h/un.h"
13 #include "../h/protosw.h"
14 #include "../h/socket.h"
15 #include "../h/socketvar.h"
16 #include "../h/stat.h"
17 #include "../h/ioctl.h"
18 #include "../h/uio.h"
19 #include "../net/route.h"
20 #include "../netinet/in.h"
21 #include "../net/if.h"
22 
23 /*
24  * Socket operation routines.
25  * These routines are called by the routines in
26  * sys_socket.c or from a system process, and
27  * implement the semantics of socket operations by
28  * switching out to the protocol specific routines.
29  *
30  * TODO:
31  *	sostat
32  *	test socketpair
33  *	PR_RIGHTS
34  *	clean up select, async
35  *	out-of-band is a kludge
36  */
37 /*ARGSUSED*/
38 socreate(dom, aso, type, proto)
39 	struct socket **aso;
40 	register int type;
41 	int proto;
42 {
43 	register struct protosw *prp;
44 	register struct socket *so;
45 	register struct mbuf *m;
46 	register int error;
47 
48 	if (proto)
49 		prp = pffindproto(dom, proto);
50 	else
51 		prp = pffindtype(dom, type);
52 	if (prp == 0)
53 		return (EPROTONOSUPPORT);
54 	if (prp->pr_type != type)
55 		return (EPROTOTYPE);
56 	m = m_getclr(M_WAIT, MT_SOCKET);
57 	if (m == 0)
58 		return (ENOBUFS);
59 	so = mtod(m, struct socket *);
60 	so->so_options = 0;
61 	so->so_state = 0;
62 	so->so_type = type;
63 	if (u.u_uid == 0)
64 		so->so_state = SS_PRIV;
65 	so->so_proto = prp;
66 	error =
67 	    (*prp->pr_usrreq)(so, PRU_ATTACH,
68 		(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
69 	if (error) {
70 		so->so_state |= SS_NOFDREF;
71 		sofree(so);
72 		return (error);
73 	}
74 	*aso = so;
75 	return (0);
76 }
77 
78 sobind(so, nam)
79 	struct socket *so;
80 	struct mbuf *nam;
81 {
82 	int s = splnet();
83 	int error;
84 
85 	error =
86 	    (*so->so_proto->pr_usrreq)(so, PRU_BIND,
87 		(struct mbuf *)0, nam, (struct mbuf *)0);
88 	splx(s);
89 	return (error);
90 }
91 
92 solisten(so, backlog)
93 	register struct socket *so;
94 	int backlog;
95 {
96 	int s = splnet(), error;
97 
98 	error =
99 	    (*so->so_proto->pr_usrreq)(so, PRU_LISTEN,
100 		(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
101 	if (error) {
102 		splx(s);
103 		return (error);
104 	}
105 	if (so->so_q == 0) {
106 		so->so_q = so;
107 		so->so_q0 = so;
108 		so->so_options |= SO_ACCEPTCONN;
109 	}
110 	if (backlog < 0)
111 		backlog = 0;
112 	so->so_qlimit = MIN(backlog, SOMAXCONN);
113 	splx(s);
114 	return (0);
115 }
116 
117 sofree(so)
118 	register struct socket *so;
119 {
120 
121 	if (so->so_head) {
122 		if (!soqremque(so, 0) && !soqremque(so, 1))
123 			panic("sofree dq");
124 		so->so_head = 0;
125 	}
126 	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)
127 		return;
128 	sbrelease(&so->so_snd);
129 	sorflush(so);
130 	(void) m_free(dtom(so));
131 }
132 
133 /*
134  * Close a socket on last file table reference removal.
135  * Initiate disconnect if connected.
136  * Free socket when disconnect complete.
137  */
138 soclose(so)
139 	register struct socket *so;
140 {
141 	int s = splnet();		/* conservative */
142 	int error;
143 
144 	if (so->so_options & SO_ACCEPTCONN) {
145 		while (so->so_q0 != so)
146 			(void) soabort(so->so_q0);
147 		while (so->so_q != so)
148 			(void) soabort(so->so_q);
149 	}
150 	if (so->so_pcb == 0)
151 		goto discard;
152 	if (so->so_state & SS_ISCONNECTED) {
153 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
154 			error = sodisconnect(so, (struct mbuf *)0);
155 			if (error)
156 				goto drop;
157 		}
158 		if (so->so_options & SO_LINGER) {
159 			if ((so->so_state & SS_ISDISCONNECTING) &&
160 			    (so->so_state & SS_NBIO))
161 				goto drop;
162 			while (so->so_state & SS_ISCONNECTED)
163 				sleep((caddr_t)&so->so_timeo, PZERO+1);
164 		}
165 	}
166 drop:
167 	if (so->so_pcb) {
168 		int error2 =
169 		    (*so->so_proto->pr_usrreq)(so, PRU_DETACH,
170 			(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
171 		if (error == 0)
172 			error = error2;
173 	}
174 discard:
175 	if (so->so_state & SS_NOFDREF)
176 		panic("soclose: NOFDREF");
177 	so->so_state |= SS_NOFDREF;
178 	sofree(so);
179 	splx(s);
180 	return (error);
181 }
182 
183 /*
184  * Must be called at splnet...
185  */
186 soabort(so)
187 	struct socket *so;
188 {
189 
190 	return (
191 	    (*so->so_proto->pr_usrreq)(so, PRU_ABORT,
192 		(struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0));
193 }
194 
195 soaccept(so, nam)
196 	register struct socket *so;
197 	struct mbuf *nam;
198 {
199 	int s = splnet();
200 	int error;
201 
202 	if ((so->so_state & SS_NOFDREF) == 0)
203 		panic("soaccept: !NOFDREF");
204 	so->so_state &= ~SS_NOFDREF;
205 	error = (*so->so_proto->pr_usrreq)(so, PRU_ACCEPT,
206 	    (struct mbuf *)0, nam, (struct mbuf *)0);
207 	splx(s);
208 	return (error);
209 }
210 
211 soconnect(so, nam)
212 	register struct socket *so;
213 	struct mbuf *nam;
214 {
215 	int s = splnet();
216 	int error;
217 
218 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) {
219 		error = EISCONN;
220 		goto bad;
221 	}
222 	error = (*so->so_proto->pr_usrreq)(so, PRU_CONNECT,
223 	    (struct mbuf *)0, nam, (struct mbuf *)0);
224 bad:
225 	splx(s);
226 	return (error);
227 }
228 
229 #ifdef notdef
230 soconnect2(so1, so2)
231 	register struct socket *so1;
232 	struct socket *so2;
233 {
234 	int s = splnet();
235 	int error;
236 
237 	error =
238 	    (*so1->so_proto->pr_usrreq)(so, PRU_CONNECT2,
239 		(struct mbuf *)0, (struct mbuf *)so2, (struct mbuf *)0);
240 	splx(s);
241 	return (error);
242 }
243 #endif
244 
245 sodisconnect(so, nam)
246 	register struct socket *so;
247 	struct mbuf *nam;
248 {
249 	int s = splnet();
250 	int error;
251 
252 	if ((so->so_state & SS_ISCONNECTED) == 0) {
253 		error = ENOTCONN;
254 		goto bad;
255 	}
256 	if (so->so_state & SS_ISDISCONNECTING) {
257 		error = EALREADY;
258 		goto bad;
259 	}
260 	error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT,
261 	    (struct mbuf *)0, nam, (struct mbuf *)0);
262 bad:
263 	splx(s);
264 	return (error);
265 }
266 
267 /*
268  * Send on a socket.
269  * If send must go all at once and message is larger than
270  * send buffering, then hard error.
271  * Lock against other senders.
272  * If must go all at once and not enough room now, then
273  * inform user that this would block and do nothing.
274  */
275 sosend(so, nam, uio, flags, rights)
276 	register struct socket *so;
277 	struct mbuf *nam;
278 	register struct uio *uio;
279 	int flags;
280 	struct mbuf *rights;
281 {
282 	struct mbuf *top = 0;
283 	register struct mbuf *m, **mp = &top;
284 	register int space;
285 	int len, error = 0, s, dontroute;
286 
287 	if (sosendallatonce(so) && uio->uio_resid > so->so_snd.sb_hiwat)
288 		return (EMSGSIZE);
289 	dontroute =
290 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
291 	    (so->so_proto->pr_flags & PR_ATOMIC);
292 restart:
293 	sblock(&so->so_snd);
294 #define	snderr(errno)	{ error = errno; splx(s); goto release; }
295 
296 	u.u_ru.ru_msgsnd++;
297 again:
298 	s = splnet();
299 	if (so->so_state & SS_CANTSENDMORE) {
300 		psignal(u.u_procp, SIGPIPE);
301 		snderr(EPIPE);
302 	}
303 	if (so->so_error) {
304 		error = so->so_error;
305 		so->so_error = 0;				/* ??? */
306 		splx(s);
307 		goto release;
308 	}
309 	if ((so->so_state & SS_ISCONNECTED) == 0) {
310 		if (so->so_proto->pr_flags & PR_CONNREQUIRED)
311 			snderr(ENOTCONN);
312 		if (nam == 0)
313 			snderr(EDESTADDRREQ);
314 	}
315 	if (top) {
316 		if (dontroute)
317 			so->so_options |= SO_DONTROUTE;
318 		error = (*so->so_proto->pr_usrreq)(so,
319 		    (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
320 		    top, (caddr_t)nam, rights);
321 		if (dontroute)
322 			so->so_options &= ~SO_DONTROUTE;
323 		top = 0;
324 		if (error) {
325 			splx(s);
326 			goto release;
327 		}
328 		mp = &top;
329 	}
330 	if (uio->uio_resid == 0) {
331 		splx(s);
332 		goto release;
333 	}
334 	if (flags & MSG_OOB)
335 		space = 1024;
336 	else {
337 		space = sbspace(&so->so_snd);
338 		if (space <= 0 ||
339 		    sosendallatonce(so) && space < uio->uio_resid) {
340 			if (so->so_state & SS_NBIO)
341 				snderr(EWOULDBLOCK);
342 			sbunlock(&so->so_snd);
343 			sbwait(&so->so_snd);
344 			splx(s);
345 			goto restart;
346 		}
347 	}
348 	splx(s);
349 	while (uio->uio_resid > 0 && space > 0) {
350 		register struct iovec *iov = uio->uio_iov;
351 
352 		if (iov->iov_len == 0) {
353 			uio->uio_iov++;
354 			uio->uio_iovcnt--;
355 			if (uio->uio_iovcnt < 0)
356 				panic("sosend");
357 			continue;
358 		}
359 		MGET(m, M_WAIT, MT_DATA);
360 		if (m == NULL) {
361 			error = ENOBUFS;			/* SIGPIPE? */
362 			goto release;
363 		}
364 		if (iov->iov_len >= CLBYTES && space >= CLBYTES) {
365 			register struct mbuf *p;
366 			MCLGET(p, 1);
367 			if (p == 0)
368 				goto nopages;
369 			m->m_off = (int)p - (int)m;
370 			len = CLBYTES;
371 		} else {
372 nopages:
373 			len = MIN(MLEN, iov->iov_len);
374 		}
375 		(void) uiomove(mtod(m, caddr_t), len, UIO_WRITE, uio);
376 		m->m_len = len;
377 		*mp = m;
378 		mp = &m->m_next;
379 		if (flags & MSG_OOB)
380 			space -= len;
381 		else
382 			space = sbspace(&so->so_snd);
383 	}
384 	goto again;
385 
386 release:
387 	sbunlock(&so->so_snd);
388 	if (top)
389 		m_freem(top);
390 	return (error);
391 }
392 
393 soreceive(so, aname, uio, flags, rightsp)
394 	register struct socket *so;
395 	struct mbuf **aname;
396 	register struct uio *uio;
397 	int flags;
398 	struct mbuf **rightsp;
399 {
400 	register struct mbuf *m, *n;
401 	register int len, error = 0, s, eor, tomark;
402 	struct protosw *pr = so->so_proto;
403 	int moff;
404 
405 	if (rightsp)
406 		*rightsp = 0;
407 	if (aname)
408 		*aname = 0;
409 	if (flags & MSG_OOB) {
410 		m = m_get(M_WAIT, MT_DATA);
411 		if (m == 0)
412 			return (ENOBUFS);
413 		error = (*pr->pr_usrreq)(so, PRU_RCVOOB,
414 		    m, (struct mbuf *)0, (struct mbuf *)0);
415 		if (error)
416 			goto bad;
417 		do {
418 			len = uio->uio_resid;
419 			if (len > m->m_len)
420 				len = m->m_len;
421 			error =
422 			    uiomove(mtod(m, caddr_t), (int)len, UIO_READ, uio);
423 			m = m_free(m);
424 		} while (uio->uio_resid && error == 0 && m);
425 bad:
426 		if (m)
427 			m_freem(m);
428 		return (error);
429 	}
430 
431 restart:
432 	sblock(&so->so_rcv);
433 	s = splnet();
434 
435 #define	rcverr(errno)	{ error = errno; splx(s); goto release; }
436 	if (so->so_rcv.sb_cc == 0) {
437 		if (so->so_error) {
438 			error = so->so_error;
439 			so->so_error = 0;
440 			splx(s);
441 			goto release;
442 		}
443 		if (so->so_state & SS_CANTRCVMORE) {
444 			splx(s);
445 			goto release;
446 		}
447 		if ((so->so_state & SS_ISCONNECTED) == 0 &&
448 		    (so->so_proto->pr_flags & PR_CONNREQUIRED))
449 			rcverr(ENOTCONN);
450 		if (so->so_state & SS_NBIO)
451 			rcverr(EWOULDBLOCK);
452 		sbunlock(&so->so_rcv);
453 		sbwait(&so->so_rcv);
454 		splx(s);
455 		goto restart;
456 	}
457 	u.u_ru.ru_msgrcv++;
458 	m = so->so_rcv.sb_mb;
459 	if (m == 0)
460 		panic("receive");
461 	if (pr->pr_flags & PR_ADDR) {
462 		if ((flags & MSG_PEEK) == 0) {
463 			so->so_rcv.sb_cc -= m->m_len;
464 			so->so_rcv.sb_mbcnt -= MSIZE;
465 		}
466 		if (aname) {
467 			if (flags & MSG_PEEK) {
468 				*aname = m_copy(m, 0, m->m_len);
469 				if (*aname == NULL)
470 					panic("receive 2");
471 			} else
472 				*aname = m;
473 			m = m->m_next;
474 			(*aname)->m_next = 0;
475 		} else
476 			if (flags & MSG_PEEK)
477 				m = m->m_next;
478 			else
479 				m = m_free(m);
480 		if (m == 0)
481 			panic("receive 2a");
482 		if (rightsp) {
483 			if (m->m_len)
484 				*rightsp = m_copy(m, 0, m->m_len);
485 			else {
486 				*rightsp = m_get(M_DONTWAIT, MT_SONAME);
487 				if (*rightsp)
488 					(*rightsp)->m_len = 0;
489 			}
490 			if (*rightsp == NULL)
491 				panic("receive 2b");
492 		}
493 		if (flags & MSG_PEEK)
494 			m = m->m_next;
495 		else {
496 			so->so_rcv.sb_cc -= m->m_len;
497 			so->so_rcv.sb_mbcnt -= MSIZE;
498 			m = m_free(m);
499 		}
500 		if (m == 0)
501 			panic("receive 3");
502 		if ((flags & MSG_PEEK) == 0)
503 			so->so_rcv.sb_mb = m;
504 	}
505 	eor = 0;
506 	moff = 0;
507 	tomark = so->so_oobmark;
508 	do {
509 		if (uio->uio_resid <= 0)
510 			break;
511 		len = uio->uio_resid;
512 		so->so_state &= ~SS_RCVATMARK;
513 		if (tomark && len > tomark)
514 			len = tomark;
515 		if (moff+len > m->m_len - moff)
516 			len = m->m_len - moff;
517 		splx(s);
518 		error =
519 		    uiomove(mtod(m, caddr_t) + moff, (int)len, UIO_READ, uio);
520 		s = splnet();
521 		if (len == m->m_len) {
522 			eor = (int)m->m_act;
523 			if (flags & MSG_PEEK)
524 				m = m->m_next;
525 			else {
526 				sbfree(&so->so_rcv, m);
527 				MFREE(m, n);
528 				m = n;
529 				so->so_rcv.sb_mb = m;
530 			}
531 			moff = 0;
532 		} else {
533 			if (flags & MSG_PEEK)
534 				moff += len;
535 			else {
536 				m->m_off += len;
537 				m->m_len -= len;
538 				so->so_rcv.sb_cc -= len;
539 			}
540 		}
541 		if ((flags & MSG_PEEK) == 0 && so->so_oobmark) {
542 			so->so_oobmark -= len;
543 			if (so->so_oobmark == 0) {
544 				so->so_state |= SS_RCVATMARK;
545 				break;
546 			}
547 		}
548 		if (tomark) {
549 			tomark -= len;
550 			if (tomark == 0)
551 				break;
552 		}
553 	} while (m && error == 0 && !eor);
554 	if (flags & MSG_PEEK)
555 		goto release;
556 	if ((so->so_proto->pr_flags & PR_ATOMIC) && eor == 0)
557 		do {
558 			if (m == 0)
559 				panic("receive 4");
560 			sbfree(&so->so_rcv, m);
561 			eor = (int)m->m_act;
562 			so->so_rcv.sb_mb = m->m_next;
563 			MFREE(m, n);
564 			m = n;
565 		} while (eor == 0);
566 	if ((so->so_proto->pr_flags & PR_WANTRCVD) && so->so_pcb)
567 		(*so->so_proto->pr_usrreq)(so, PRU_RCVD,
568 		    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
569 release:
570 	sbunlock(&so->so_rcv);
571 	if (error == 0 && rightsp &&
572 	    *rightsp && so->so_proto->pr_family == AF_UNIX)
573 		error = unp_externalize(*rightsp);
574 	splx(s);
575 	return (error);
576 }
577 
578 soshutdown(so, how)
579 	register struct socket *so;
580 	register int how;
581 {
582 	register struct protosw *pr = so->so_proto;
583 
584 	how++;
585 	if (how & FREAD)
586 		sorflush(so);
587 	if (how & FWRITE)
588 		return ((*pr->pr_usrreq)(so, PRU_SHUTDOWN,
589 		    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0));
590 	return (0);
591 }
592 
593 sorflush(so)
594 	register struct socket *so;
595 {
596 	register struct sockbuf *sb = &so->so_rcv;
597 	register struct protosw *pr = so->so_proto;
598 	register int s;
599 	struct sockbuf asb;
600 
601 	sblock(sb);
602 	s = splimp();
603 	socantrcvmore(so);
604 	sbunlock(sb);
605 	asb = *sb;
606 	bzero((caddr_t)sb, sizeof (*sb));
607 	splx(s);
608 	if (pr->pr_family == AF_UNIX && (pr->pr_flags & PR_RIGHTS))
609 		unp_scan(asb.sb_mb, unp_discard);
610 	sbrelease(&asb);
611 }
612 
613 sosetopt(so, level, optname, m)
614 	register struct socket *so;
615 	int level, optname;
616 	register struct mbuf *m;
617 {
618 
619 	if (level != SOL_SOCKET)
620 		return (EINVAL);	/* XXX */
621 	switch (optname) {
622 
623 	case SO_DEBUG:
624 	case SO_KEEPALIVE:
625 	case SO_DONTROUTE:
626 	case SO_USELOOPBACK:
627 	case SO_REUSEADDR:
628 		so->so_options |= optname;
629 		break;
630 
631 	case SO_LINGER:
632 		if (m == NULL || m->m_len != sizeof (int))
633 			return (EINVAL);
634 		so->so_options |= SO_LINGER;
635 		so->so_linger = *mtod(m, int *);
636 		break;
637 
638 	case SO_DONTLINGER:
639 		so->so_options &= ~SO_LINGER;
640 		so->so_linger = 0;
641 		break;
642 
643 	default:
644 		return (EINVAL);
645 	}
646 	return (0);
647 }
648 
649 sogetopt(so, level, optname, m)
650 	register struct socket *so;
651 	int level, optname;
652 	register struct mbuf *m;
653 {
654 
655 	if (level != SOL_SOCKET)
656 		return (EINVAL);	/* XXX */
657 	switch (optname) {
658 
659 	case SO_USELOOPBACK:
660 	case SO_DONTROUTE:
661 	case SO_DEBUG:
662 	case SO_KEEPALIVE:
663 	case SO_LINGER:
664 	case SO_REUSEADDR:
665 		if ((so->so_options & optname) == 0)
666 			return (ENOPROTOOPT);
667 		if (optname == SO_LINGER && m != NULL) {
668 			*mtod(m, int *) = so->so_linger;
669 			m->m_len = sizeof (so->so_linger);
670 		}
671 		break;
672 
673 	default:
674 		return (EINVAL);
675 	}
676 	return (0);
677 }
678 
679 sohasoutofband(so)
680 	register struct socket *so;
681 {
682 
683 	if (so->so_pgrp == 0)
684 		return;
685 	if (so->so_pgrp > 0)
686 		gsignal(so->so_pgrp, SIGURG);
687 	else {
688 		struct proc *p = pfind(-so->so_pgrp);
689 
690 		if (p)
691 			psignal(p, SIGURG);
692 	}
693 }
694