xref: /csrg-svn/sys/kern/uipc_socket.c (revision 13113)
1 /*	uipc_socket.c	4.76	83/06/14	*/
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 soconnect2(so1, so2)
230 	register struct socket *so1;
231 	struct socket *so2;
232 {
233 	int s = splnet();
234 	int error;
235 
236 	error = (*so1->so_proto->pr_usrreq)(so1, PRU_CONNECT2,
237 	    (struct mbuf *)0, (struct mbuf *)so2, (struct mbuf *)0);
238 	splx(s);
239 	return (error);
240 }
241 
242 sodisconnect(so, nam)
243 	register struct socket *so;
244 	struct mbuf *nam;
245 {
246 	int s = splnet();
247 	int error;
248 
249 	if ((so->so_state & SS_ISCONNECTED) == 0) {
250 		error = ENOTCONN;
251 		goto bad;
252 	}
253 	if (so->so_state & SS_ISDISCONNECTING) {
254 		error = EALREADY;
255 		goto bad;
256 	}
257 	error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT,
258 	    (struct mbuf *)0, nam, (struct mbuf *)0);
259 bad:
260 	splx(s);
261 	return (error);
262 }
263 
264 /*
265  * Send on a socket.
266  * If send must go all at once and message is larger than
267  * send buffering, then hard error.
268  * Lock against other senders.
269  * If must go all at once and not enough room now, then
270  * inform user that this would block and do nothing.
271  */
272 sosend(so, nam, uio, flags, rights)
273 	register struct socket *so;
274 	struct mbuf *nam;
275 	register struct uio *uio;
276 	int flags;
277 	struct mbuf *rights;
278 {
279 	struct mbuf *top = 0;
280 	register struct mbuf *m, **mp = &top;
281 	register int space;
282 	int len, error = 0, s, dontroute;
283 
284 	if (sosendallatonce(so) && uio->uio_resid > so->so_snd.sb_hiwat)
285 		return (EMSGSIZE);
286 	dontroute =
287 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
288 	    (so->so_proto->pr_flags & PR_ATOMIC);
289 restart:
290 	sblock(&so->so_snd);
291 #define	snderr(errno)	{ error = errno; splx(s); goto release; }
292 
293 	u.u_ru.ru_msgsnd++;
294 again:
295 	s = splnet();
296 	if (so->so_state & SS_CANTSENDMORE) {
297 		psignal(u.u_procp, SIGPIPE);
298 		snderr(EPIPE);
299 	}
300 	if (so->so_error) {
301 		error = so->so_error;
302 		so->so_error = 0;				/* ??? */
303 		splx(s);
304 		goto release;
305 	}
306 	if ((so->so_state & SS_ISCONNECTED) == 0) {
307 		if (so->so_proto->pr_flags & PR_CONNREQUIRED)
308 			snderr(ENOTCONN);
309 		if (nam == 0)
310 			snderr(EDESTADDRREQ);
311 	}
312 	if (top) {
313 		if (dontroute)
314 			so->so_options |= SO_DONTROUTE;
315 		error = (*so->so_proto->pr_usrreq)(so,
316 		    (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
317 		    top, (caddr_t)nam, rights);
318 		if (dontroute)
319 			so->so_options &= ~SO_DONTROUTE;
320 		top = 0;
321 		if (error) {
322 			splx(s);
323 			goto release;
324 		}
325 		mp = &top;
326 	}
327 	if (uio->uio_resid == 0) {
328 		splx(s);
329 		goto release;
330 	}
331 	if (flags & MSG_OOB)
332 		space = 1024;
333 	else {
334 		space = sbspace(&so->so_snd);
335 		if (space <= 0 ||
336 		    sosendallatonce(so) && space < uio->uio_resid) {
337 			if (so->so_state & SS_NBIO)
338 				snderr(EWOULDBLOCK);
339 			sbunlock(&so->so_snd);
340 			sbwait(&so->so_snd);
341 			splx(s);
342 			goto restart;
343 		}
344 	}
345 	splx(s);
346 	while (uio->uio_resid > 0 && space > 0) {
347 		register struct iovec *iov = uio->uio_iov;
348 
349 		if (iov->iov_len == 0) {
350 			uio->uio_iov++;
351 			uio->uio_iovcnt--;
352 			if (uio->uio_iovcnt < 0)
353 				panic("sosend");
354 			continue;
355 		}
356 		MGET(m, M_WAIT, MT_DATA);
357 		if (m == NULL) {
358 			error = ENOBUFS;			/* SIGPIPE? */
359 			goto release;
360 		}
361 		if (iov->iov_len >= CLBYTES && space >= CLBYTES) {
362 			register struct mbuf *p;
363 			MCLGET(p, 1);
364 			if (p == 0)
365 				goto nopages;
366 			m->m_off = (int)p - (int)m;
367 			len = CLBYTES;
368 		} else {
369 nopages:
370 			len = MIN(MLEN, iov->iov_len);
371 		}
372 		(void) uiomove(mtod(m, caddr_t), len, UIO_WRITE, uio);
373 		m->m_len = len;
374 		*mp = m;
375 		mp = &m->m_next;
376 		if (flags & MSG_OOB)
377 			space -= len;
378 		else
379 			space = sbspace(&so->so_snd);
380 	}
381 	goto again;
382 
383 release:
384 	sbunlock(&so->so_snd);
385 	if (top)
386 		m_freem(top);
387 	return (error);
388 }
389 
390 soreceive(so, aname, uio, flags, rightsp)
391 	register struct socket *so;
392 	struct mbuf **aname;
393 	register struct uio *uio;
394 	int flags;
395 	struct mbuf **rightsp;
396 {
397 	register struct mbuf *m, *n;
398 	register int len, error = 0, s, eor, tomark;
399 	struct protosw *pr = so->so_proto;
400 	int moff;
401 
402 	if (rightsp)
403 		*rightsp = 0;
404 	if (aname)
405 		*aname = 0;
406 	if (flags & MSG_OOB) {
407 		m = m_get(M_WAIT, MT_DATA);
408 		if (m == 0)
409 			return (ENOBUFS);
410 		error = (*pr->pr_usrreq)(so, PRU_RCVOOB,
411 		    m, (struct mbuf *)0, (struct mbuf *)0);
412 		if (error)
413 			goto bad;
414 		do {
415 			len = uio->uio_resid;
416 			if (len > m->m_len)
417 				len = m->m_len;
418 			error =
419 			    uiomove(mtod(m, caddr_t), (int)len, UIO_READ, uio);
420 			m = m_free(m);
421 		} while (uio->uio_resid && error == 0 && m);
422 bad:
423 		if (m)
424 			m_freem(m);
425 		return (error);
426 	}
427 
428 restart:
429 	sblock(&so->so_rcv);
430 	s = splnet();
431 
432 #define	rcverr(errno)	{ error = errno; splx(s); goto release; }
433 	if (so->so_rcv.sb_cc == 0) {
434 		if (so->so_error) {
435 			error = so->so_error;
436 			so->so_error = 0;
437 			splx(s);
438 			goto release;
439 		}
440 		if (so->so_state & SS_CANTRCVMORE) {
441 			splx(s);
442 			goto release;
443 		}
444 		if ((so->so_state & SS_ISCONNECTED) == 0 &&
445 		    (so->so_proto->pr_flags & PR_CONNREQUIRED))
446 			rcverr(ENOTCONN);
447 		if (so->so_state & SS_NBIO)
448 			rcverr(EWOULDBLOCK);
449 		sbunlock(&so->so_rcv);
450 		sbwait(&so->so_rcv);
451 		splx(s);
452 		goto restart;
453 	}
454 	u.u_ru.ru_msgrcv++;
455 	m = so->so_rcv.sb_mb;
456 	if (m == 0)
457 		panic("receive");
458 	if (pr->pr_flags & PR_ADDR) {
459 		if ((flags & MSG_PEEK) == 0) {
460 			so->so_rcv.sb_cc -= m->m_len;
461 			so->so_rcv.sb_mbcnt -= MSIZE;
462 		}
463 		if (aname) {
464 			if (flags & MSG_PEEK) {
465 				*aname = m_copy(m, 0, m->m_len);
466 				if (*aname == NULL)
467 					panic("receive 2");
468 			} else
469 				*aname = m;
470 			m = m->m_next;
471 			(*aname)->m_next = 0;
472 		} else
473 			if (flags & MSG_PEEK)
474 				m = m->m_next;
475 			else
476 				m = m_free(m);
477 		if (m == 0)
478 			panic("receive 2a");
479 		if (rightsp) {
480 			if (m->m_len)
481 				*rightsp = m_copy(m, 0, m->m_len);
482 			else {
483 				*rightsp = m_get(M_DONTWAIT, MT_SONAME);
484 				if (*rightsp)
485 					(*rightsp)->m_len = 0;
486 			}
487 			if (*rightsp == NULL)
488 				panic("receive 2b");
489 		}
490 		if (flags & MSG_PEEK)
491 			m = m->m_next;
492 		else {
493 			so->so_rcv.sb_cc -= m->m_len;
494 			so->so_rcv.sb_mbcnt -= MSIZE;
495 			m = m_free(m);
496 		}
497 		if (m == 0)
498 			panic("receive 3");
499 		if ((flags & MSG_PEEK) == 0)
500 			so->so_rcv.sb_mb = m;
501 	}
502 	eor = 0;
503 	moff = 0;
504 	tomark = so->so_oobmark;
505 	do {
506 		if (uio->uio_resid <= 0)
507 			break;
508 		len = uio->uio_resid;
509 		so->so_state &= ~SS_RCVATMARK;
510 		if (tomark && len > tomark)
511 			len = tomark;
512 		if (moff+len > m->m_len - moff)
513 			len = m->m_len - moff;
514 		splx(s);
515 		error =
516 		    uiomove(mtod(m, caddr_t) + moff, (int)len, UIO_READ, uio);
517 		s = splnet();
518 		if (len == m->m_len) {
519 			eor = (int)m->m_act;
520 			if (flags & MSG_PEEK)
521 				m = m->m_next;
522 			else {
523 				sbfree(&so->so_rcv, m);
524 				MFREE(m, n);
525 				m = n;
526 				so->so_rcv.sb_mb = m;
527 			}
528 			moff = 0;
529 		} else {
530 			if (flags & MSG_PEEK)
531 				moff += len;
532 			else {
533 				m->m_off += len;
534 				m->m_len -= len;
535 				so->so_rcv.sb_cc -= len;
536 			}
537 		}
538 		if ((flags & MSG_PEEK) == 0 && so->so_oobmark) {
539 			so->so_oobmark -= len;
540 			if (so->so_oobmark == 0) {
541 				so->so_state |= SS_RCVATMARK;
542 				break;
543 			}
544 		}
545 		if (tomark) {
546 			tomark -= len;
547 			if (tomark == 0)
548 				break;
549 		}
550 	} while (m && error == 0 && !eor);
551 	if (flags & MSG_PEEK)
552 		goto release;
553 	if ((so->so_proto->pr_flags & PR_ATOMIC) && eor == 0)
554 		do {
555 			if (m == 0)
556 				panic("receive 4");
557 			sbfree(&so->so_rcv, m);
558 			eor = (int)m->m_act;
559 			so->so_rcv.sb_mb = m->m_next;
560 			MFREE(m, n);
561 			m = n;
562 		} while (eor == 0);
563 	if ((so->so_proto->pr_flags & PR_WANTRCVD) && so->so_pcb)
564 		(*so->so_proto->pr_usrreq)(so, PRU_RCVD,
565 		    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0);
566 release:
567 	sbunlock(&so->so_rcv);
568 	if (error == 0 && rightsp &&
569 	    *rightsp && so->so_proto->pr_family == AF_UNIX)
570 		error = unp_externalize(*rightsp);
571 	splx(s);
572 	return (error);
573 }
574 
575 soshutdown(so, how)
576 	register struct socket *so;
577 	register int how;
578 {
579 	register struct protosw *pr = so->so_proto;
580 
581 	how++;
582 	if (how & FREAD)
583 		sorflush(so);
584 	if (how & FWRITE)
585 		return ((*pr->pr_usrreq)(so, PRU_SHUTDOWN,
586 		    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0));
587 	return (0);
588 }
589 
590 sorflush(so)
591 	register struct socket *so;
592 {
593 	register struct sockbuf *sb = &so->so_rcv;
594 	register struct protosw *pr = so->so_proto;
595 	register int s;
596 	struct sockbuf asb;
597 
598 	sblock(sb);
599 	s = splimp();
600 	socantrcvmore(so);
601 	sbunlock(sb);
602 	asb = *sb;
603 	bzero((caddr_t)sb, sizeof (*sb));
604 	splx(s);
605 	if (pr->pr_family == AF_UNIX && (pr->pr_flags & PR_RIGHTS))
606 		unp_scan(asb.sb_mb, unp_discard);
607 	sbrelease(&asb);
608 }
609 
610 sosetopt(so, level, optname, m)
611 	register struct socket *so;
612 	int level, optname;
613 	register struct mbuf *m;
614 {
615 
616 	if (level != SOL_SOCKET)
617 		return (EINVAL);	/* XXX */
618 	switch (optname) {
619 
620 	case SO_DEBUG:
621 	case SO_KEEPALIVE:
622 	case SO_DONTROUTE:
623 	case SO_USELOOPBACK:
624 	case SO_REUSEADDR:
625 		so->so_options |= optname;
626 		break;
627 
628 	case SO_LINGER:
629 		if (m == NULL || m->m_len != sizeof (int))
630 			return (EINVAL);
631 		so->so_options |= SO_LINGER;
632 		so->so_linger = *mtod(m, int *);
633 		break;
634 
635 	case SO_DONTLINGER:
636 		so->so_options &= ~SO_LINGER;
637 		so->so_linger = 0;
638 		break;
639 
640 	default:
641 		return (EINVAL);
642 	}
643 	return (0);
644 }
645 
646 sogetopt(so, level, optname, m)
647 	register struct socket *so;
648 	int level, optname;
649 	register struct mbuf *m;
650 {
651 
652 	if (level != SOL_SOCKET)
653 		return (EINVAL);	/* XXX */
654 	switch (optname) {
655 
656 	case SO_USELOOPBACK:
657 	case SO_DONTROUTE:
658 	case SO_DEBUG:
659 	case SO_KEEPALIVE:
660 	case SO_LINGER:
661 	case SO_REUSEADDR:
662 		if ((so->so_options & optname) == 0)
663 			return (ENOPROTOOPT);
664 		if (optname == SO_LINGER && m != NULL) {
665 			*mtod(m, int *) = so->so_linger;
666 			m->m_len = sizeof (so->so_linger);
667 		}
668 		break;
669 
670 	default:
671 		return (EINVAL);
672 	}
673 	return (0);
674 }
675 
676 sohasoutofband(so)
677 	register struct socket *so;
678 {
679 
680 	if (so->so_pgrp == 0)
681 		return;
682 	if (so->so_pgrp > 0)
683 		gsignal(so->so_pgrp, SIGURG);
684 	else {
685 		struct proc *p = pfind(-so->so_pgrp);
686 
687 		if (p)
688 			psignal(p, SIGURG);
689 	}
690 }
691