2 * Copyright (c) 2005 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 1982, 1986, 1988, 1990, 1993
4 * The Regents of the University of California. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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10 * notice, this list of conditions and the following disclaimer.
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12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93
35 * $FreeBSD: src/sys/kern/uipc_socket2.c,v 1.55.2.17 2002/08/31 19:04:55 dwmalone Exp $
36 * $DragonFly: src/sys/kern/uipc_socket2.c,v 1.29 2007/05/23 08:57:05 dillon Exp $
39 #include "opt_param.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/domain.h>
43 #include <sys/file.h> /* for maxfiles */
44 #include <sys/kernel.h>
46 #include <sys/malloc.h>
48 #include <sys/protosw.h>
49 #include <sys/resourcevar.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/signalvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/aio.h> /* for aio_swake proto */
56 #include <sys/event.h>
58 #include <sys/thread2.h>
59 #include <sys/msgport2.h>
64 * Primitive routines for operating on sockets and socket buffers
67 u_long sb_max = SB_MAX;
69 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
71 static u_long sb_efficiency = 8; /* parameter for sbreserve() */
73 /************************************************************************
74 * signalsockbuf procedures *
75 ************************************************************************/
78 * Wait for data to arrive at/drain from a socket buffer.
81 ssb_wait(struct signalsockbuf *ssb)
84 ssb->ssb_flags |= SSB_WAIT;
85 return (tsleep((caddr_t)&ssb->ssb_cc,
86 ((ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH),
92 * Lock a sockbuf already known to be locked;
93 * return any error returned from sleep (EINTR).
96 _ssb_lock(struct signalsockbuf *ssb)
100 while (ssb->ssb_flags & SSB_LOCK) {
101 ssb->ssb_flags |= SSB_WANT;
102 error = tsleep((caddr_t)&ssb->ssb_flags,
103 ((ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH),
108 ssb->ssb_flags |= SSB_LOCK;
113 * This does the same for sockbufs. Note that the xsockbuf structure,
114 * since it is always embedded in a socket, does not include a self
115 * pointer nor a length. We make this entry point public in case
116 * some other mechanism needs it.
119 ssbtoxsockbuf(struct signalsockbuf *ssb, struct xsockbuf *xsb)
121 xsb->sb_cc = ssb->ssb_cc;
122 xsb->sb_hiwat = ssb->ssb_hiwat;
123 xsb->sb_mbcnt = ssb->ssb_mbcnt;
124 xsb->sb_mbmax = ssb->ssb_mbmax;
125 xsb->sb_lowat = ssb->ssb_lowat;
126 xsb->sb_flags = ssb->ssb_flags;
127 xsb->sb_timeo = ssb->ssb_timeo;
131 /************************************************************************
132 * Procedures which manipulate socket state flags, wakeups, etc. *
133 ************************************************************************
135 * Normal sequence from the active (originating) side is that
136 * soisconnecting() is called during processing of connect() call, resulting
137 * in an eventual call to soisconnected() if/when the connection is
138 * established. When the connection is torn down soisdisconnecting() is
139 * called during processing of disconnect() call, and soisdisconnected() is
140 * called when the connection to the peer is totally severed.
142 * The semantics of these routines are such that connectionless protocols
143 * can call soisconnected() and soisdisconnected() only, bypassing the
144 * in-progress calls when setting up a ``connection'' takes no time.
146 * From the passive side, a socket is created with two queues of sockets:
147 * so_incomp for connections in progress and so_comp for connections
148 * already made and awaiting user acceptance. As a protocol is preparing
149 * incoming connections, it creates a socket structure queued on so_incomp
150 * by calling sonewconn(). When the connection is established,
151 * soisconnected() is called, and transfers the socket structure to so_comp,
152 * making it available to accept().
154 * If a socket is closed with sockets on either so_incomp or so_comp, these
155 * sockets are dropped.
157 * If higher level protocols are implemented in the kernel, the wakeups
158 * done here will sometimes cause software-interrupt process scheduling.
162 soisconnecting(struct socket *so)
164 so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
165 so->so_state |= SS_ISCONNECTING;
169 soisconnected(struct socket *so)
171 struct socket *head = so->so_head;
173 so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
174 so->so_state |= SS_ISCONNECTED;
175 if (head && (so->so_state & SS_INCOMP)) {
176 if ((so->so_options & SO_ACCEPTFILTER) != 0) {
177 so->so_upcall = head->so_accf->so_accept_filter->accf_callback;
178 so->so_upcallarg = head->so_accf->so_accept_filter_arg;
179 so->so_rcv.ssb_flags |= SSB_UPCALL;
180 so->so_options &= ~SO_ACCEPTFILTER;
181 so->so_upcall(so, so->so_upcallarg, 0);
184 TAILQ_REMOVE(&head->so_incomp, so, so_list);
186 so->so_state &= ~SS_INCOMP;
187 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
189 so->so_state |= SS_COMP;
191 wakeup_one(&head->so_timeo);
193 wakeup(&so->so_timeo);
200 soisdisconnecting(struct socket *so)
202 so->so_state &= ~SS_ISCONNECTING;
203 so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
204 wakeup((caddr_t)&so->so_timeo);
210 soisdisconnected(struct socket *so)
212 so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
213 so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
214 wakeup((caddr_t)&so->so_timeo);
215 sbdrop(&so->so_snd.sb, so->so_snd.ssb_cc);
221 * When an attempt at a new connection is noted on a socket
222 * which accepts connections, sonewconn is called. If the
223 * connection is possible (subject to space constraints, etc.)
224 * then we allocate a new structure, propoerly linked into the
225 * data structure of the original socket, and return this.
226 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
229 sonewconn(struct socket *head, int connstatus)
232 struct pru_attach_info ai;
234 if (head->so_qlen > 3 * head->so_qlimit / 2)
235 return ((struct socket *)0);
239 if ((head->so_options & SO_ACCEPTFILTER) != 0)
242 so->so_type = head->so_type;
243 so->so_options = head->so_options &~ SO_ACCEPTCONN;
244 so->so_linger = head->so_linger;
245 so->so_state = head->so_state | SS_NOFDREF;
246 so->so_proto = head->so_proto;
247 so->so_timeo = head->so_timeo;
248 so->so_cred = crhold(head->so_cred);
251 ai.fd_rdir = NULL; /* jail code cruft XXX JH */
252 if (soreserve(so, head->so_snd.ssb_hiwat, head->so_rcv.ssb_hiwat, NULL) ||
253 /* Directly call function since we're already at protocol level. */
254 (*so->so_proto->pr_usrreqs->pru_attach)(so, 0, &ai)) {
256 return ((struct socket *)0);
260 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
261 so->so_state |= SS_COMP;
264 if (head->so_incqlen > head->so_qlimit) {
266 sp = TAILQ_FIRST(&head->so_incomp);
269 TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list);
270 so->so_state |= SS_INCOMP;
275 wakeup((caddr_t)&head->so_timeo);
276 so->so_state |= connstatus;
282 * Socantsendmore indicates that no more data will be sent on the
283 * socket; it would normally be applied to a socket when the user
284 * informs the system that no more data is to be sent, by the protocol
285 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
286 * will be received, and will normally be applied to the socket by a
287 * protocol when it detects that the peer will send no more data.
288 * Data queued for reading in the socket may yet be read.
291 socantsendmore(struct socket *so)
293 so->so_state |= SS_CANTSENDMORE;
298 socantrcvmore(struct socket *so)
300 so->so_state |= SS_CANTRCVMORE;
305 * Wakeup processes waiting on a socket buffer. Do asynchronous notification
306 * via SIGIO if the socket has the SS_ASYNC flag set.
309 sowakeup(struct socket *so, struct signalsockbuf *ssb)
311 struct selinfo *selinfo = &ssb->ssb_sel;
314 ssb->ssb_flags &= ~SSB_SEL;
315 if (ssb->ssb_flags & SSB_WAIT) {
316 ssb->ssb_flags &= ~SSB_WAIT;
317 wakeup((caddr_t)&ssb->ssb_cc);
319 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
320 pgsigio(so->so_sigio, SIGIO, 0);
321 if (ssb->ssb_flags & SSB_UPCALL)
322 (*so->so_upcall)(so, so->so_upcallarg, MB_DONTWAIT);
323 if (ssb->ssb_flags & SSB_AIO)
325 KNOTE(&selinfo->si_note, 0);
326 if (ssb->ssb_flags & SSB_MEVENT) {
327 struct netmsg_so_notify *msg, *nmsg;
329 TAILQ_FOREACH_MUTABLE(msg, &selinfo->si_mlist, nm_list, nmsg) {
330 if (msg->nm_predicate(&msg->nm_netmsg)) {
331 TAILQ_REMOVE(&selinfo->si_mlist, msg, nm_list);
332 lwkt_replymsg(&msg->nm_netmsg.nm_lmsg,
333 msg->nm_netmsg.nm_lmsg.ms_error);
336 if (TAILQ_EMPTY(&ssb->ssb_sel.si_mlist))
337 ssb->ssb_flags &= ~SSB_MEVENT;
342 * Socket buffer (struct signalsockbuf) utility routines.
344 * Each socket contains two socket buffers: one for sending data and
345 * one for receiving data. Each buffer contains a queue of mbufs,
346 * information about the number of mbufs and amount of data in the
347 * queue, and other fields allowing select() statements and notification
348 * on data availability to be implemented.
350 * Data stored in a socket buffer is maintained as a list of records.
351 * Each record is a list of mbufs chained together with the m_next
352 * field. Records are chained together with the m_nextpkt field. The upper
353 * level routine soreceive() expects the following conventions to be
354 * observed when placing information in the receive buffer:
356 * 1. If the protocol requires each message be preceded by the sender's
357 * name, then a record containing that name must be present before
358 * any associated data (mbuf's must be of type MT_SONAME).
359 * 2. If the protocol supports the exchange of ``access rights'' (really
360 * just additional data associated with the message), and there are
361 * ``rights'' to be received, then a record containing this data
362 * should be present (mbuf's must be of type MT_RIGHTS).
363 * 3. If a name or rights record exists, then it must be followed by
364 * a data record, perhaps of zero length.
366 * Before using a new socket structure it is first necessary to reserve
367 * buffer space to the socket, by calling sbreserve(). This should commit
368 * some of the available buffer space in the system buffer pool for the
369 * socket (currently, it does nothing but enforce limits). The space
370 * should be released by calling ssb_release() when the socket is destroyed.
373 soreserve(struct socket *so, u_long sndcc, u_long rcvcc, struct rlimit *rl)
375 if (ssb_reserve(&so->so_snd, sndcc, so, rl) == 0)
377 if (ssb_reserve(&so->so_rcv, rcvcc, so, rl) == 0)
379 if (so->so_rcv.ssb_lowat == 0)
380 so->so_rcv.ssb_lowat = 1;
381 if (so->so_snd.ssb_lowat == 0)
382 so->so_snd.ssb_lowat = MCLBYTES;
383 if (so->so_snd.ssb_lowat > so->so_snd.ssb_hiwat)
384 so->so_snd.ssb_lowat = so->so_snd.ssb_hiwat;
387 ssb_release(&so->so_snd, so);
393 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)
396 u_long old_sb_max = sb_max;
398 error = SYSCTL_OUT(req, arg1, sizeof(int));
399 if (error || !req->newptr)
401 error = SYSCTL_IN(req, arg1, sizeof(int));
404 if (sb_max < MSIZE + MCLBYTES) {
408 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
413 * Allot mbufs to a signalsockbuf.
414 * Attempt to scale mbmax so that mbcnt doesn't become limiting
415 * if buffering efficiency is near the normal case.
418 ssb_reserve(struct signalsockbuf *ssb, u_long cc, struct socket *so,
422 * rl will only be NULL when we're in an interrupt (eg, in tcp_input)
423 * or when called from netgraph (ie, ngd_attach)
427 if (!chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, cc,
428 rl ? rl->rlim_cur : RLIM_INFINITY)) {
431 ssb->ssb_mbmax = min(cc * sb_efficiency, sb_max);
432 if (ssb->ssb_lowat > ssb->ssb_hiwat)
433 ssb->ssb_lowat = ssb->ssb_hiwat;
438 * Free mbufs held by a socket, and reserved mbuf space.
441 ssb_release(struct signalsockbuf *ssb, struct socket *so)
444 (void)chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, 0,
450 * Some routines that return EOPNOTSUPP for entry points that are not
451 * supported by a protocol. Fill in as needed.
454 pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
460 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
466 pru_connect2_notsupp(struct socket *so1, struct socket *so2)
472 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
473 struct ifnet *ifp, struct thread *td)
479 pru_listen_notsupp(struct socket *so, struct thread *td)
485 pru_rcvd_notsupp(struct socket *so, int flags)
491 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
497 * This isn't really a ``null'' operation, but it's the default one
498 * and doesn't do anything destructive.
501 pru_sense_null(struct socket *so, struct stat *sb)
503 sb->st_blksize = so->so_snd.ssb_hiwat;
508 * Make a copy of a sockaddr in a malloced buffer of type M_SONAME. Callers
509 * of this routine assume that it always succeeds, so we have to use a
510 * blockable allocation even though we might be called from a critical thread.
513 dup_sockaddr(const struct sockaddr *sa)
515 struct sockaddr *sa2;
517 sa2 = kmalloc(sa->sa_len, M_SONAME, M_INTWAIT);
518 bcopy(sa, sa2, sa->sa_len);
523 * Create an external-format (``xsocket'') structure using the information
524 * in the kernel-format socket structure pointed to by so. This is done
525 * to reduce the spew of irrelevant information over this interface,
526 * to isolate user code from changes in the kernel structure, and
527 * potentially to provide information-hiding if we decide that
528 * some of this information should be hidden from users.
531 sotoxsocket(struct socket *so, struct xsocket *xso)
533 xso->xso_len = sizeof *xso;
535 xso->so_type = so->so_type;
536 xso->so_options = so->so_options;
537 xso->so_linger = so->so_linger;
538 xso->so_state = so->so_state;
539 xso->so_pcb = so->so_pcb;
540 xso->xso_protocol = so->so_proto->pr_protocol;
541 xso->xso_family = so->so_proto->pr_domain->dom_family;
542 xso->so_qlen = so->so_qlen;
543 xso->so_incqlen = so->so_incqlen;
544 xso->so_qlimit = so->so_qlimit;
545 xso->so_timeo = so->so_timeo;
546 xso->so_error = so->so_error;
547 xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
548 xso->so_oobmark = so->so_oobmark;
549 ssbtoxsockbuf(&so->so_snd, &xso->so_snd);
550 ssbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
551 xso->so_uid = so->so_cred->cr_uid;
555 * Here is the definition of some of the basic objects in the kern.ipc
558 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
560 /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
562 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, "");
563 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT|CTLFLAG_RW,
564 &sb_max, 0, sysctl_handle_sb_max, "I", "Maximum socket buffer size");
565 SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD,
566 &maxsockets, 0, "Maximum number of sockets avaliable");
567 SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
568 &sb_efficiency, 0, "");
571 * Initialize maxsockets
574 init_maxsockets(void *ignored)
576 TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
577 maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters));
579 SYSINIT(param, SI_BOOT1_TUNABLES, SI_ORDER_ANY,
580 init_maxsockets, NULL);