2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
33 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
34 * $FreeBSD: src/sys/kern/uipc_usrreq.c,v 1.54.2.10 2003/03/04 17:28:09 nectar Exp $
35 * $DragonFly: src/sys/kern/uipc_usrreq.c,v 1.18 2004/12/20 11:03:16 joerg Exp $
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/domain.h>
42 #include <sys/fcntl.h>
43 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */
46 #include <sys/filedesc.h>
48 #include <sys/nlookup.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
52 #include <sys/resourcevar.h>
54 #include <sys/mount.h>
55 #include <sys/sysctl.h>
57 #include <sys/unpcb.h>
58 #include <sys/vnode.h>
59 #include <sys/file2.h>
61 #include <vm/vm_zone.h>
63 static struct vm_zone *unp_zone;
64 static unp_gen_t unp_gencnt;
65 static u_int unp_count;
67 static struct unp_head unp_shead, unp_dhead;
70 * Unix communications domain.
74 * rethink name space problems
75 * need a proper out-of-band
78 static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
79 static ino_t unp_ino; /* prototype for fake inode numbers */
81 static int unp_attach (struct socket *, struct pru_attach_info *);
82 static void unp_detach (struct unpcb *);
83 static int unp_bind (struct unpcb *,struct sockaddr *, struct thread *);
84 static int unp_connect (struct socket *,struct sockaddr *,
86 static void unp_disconnect (struct unpcb *);
87 static void unp_shutdown (struct unpcb *);
88 static void unp_drop (struct unpcb *, int);
89 static void unp_gc (void);
90 static void unp_scan (struct mbuf *, void (*)(struct file *));
91 static void unp_mark (struct file *);
92 static void unp_discard (struct file *);
93 static int unp_internalize (struct mbuf *, struct thread *);
94 static int unp_listen (struct unpcb *, struct thread *);
97 uipc_abort(struct socket *so)
99 struct unpcb *unp = sotounpcb(so);
103 unp_drop(unp, ECONNABORTED);
110 uipc_accept(struct socket *so, struct sockaddr **nam)
112 struct unpcb *unp = sotounpcb(so);
118 * Pass back name of connected socket,
119 * if it was bound and we are still connected
120 * (our peer may have closed already!).
122 if (unp->unp_conn && unp->unp_conn->unp_addr) {
123 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr);
125 *nam = dup_sockaddr((struct sockaddr *)&sun_noname);
131 uipc_attach(struct socket *so, int proto, struct pru_attach_info *ai)
133 struct unpcb *unp = sotounpcb(so);
137 return unp_attach(so, ai);
141 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
143 struct unpcb *unp = sotounpcb(so);
147 return unp_bind(unp, nam, td);
151 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
153 struct unpcb *unp = sotounpcb(so);
157 return unp_connect(so, nam, td);
161 uipc_connect2(struct socket *so1, struct socket *so2)
163 struct unpcb *unp = sotounpcb(so1);
168 return unp_connect2(so1, so2);
171 /* control is EOPNOTSUPP */
174 uipc_detach(struct socket *so)
176 struct unpcb *unp = sotounpcb(so);
186 uipc_disconnect(struct socket *so)
188 struct unpcb *unp = sotounpcb(so);
197 uipc_listen(struct socket *so, struct thread *td)
199 struct unpcb *unp = sotounpcb(so);
201 if (unp == 0 || unp->unp_vnode == 0)
203 return unp_listen(unp, td);
207 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
209 struct unpcb *unp = sotounpcb(so);
213 if (unp->unp_conn && unp->unp_conn->unp_addr)
214 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr);
217 * XXX: It seems that this test always fails even when
218 * connection is established. So, this else clause is
219 * added as workaround to return PF_LOCAL sockaddr.
221 *nam = dup_sockaddr((struct sockaddr *)&sun_noname);
227 uipc_rcvd(struct socket *so, int flags)
229 struct unpcb *unp = sotounpcb(so);
235 switch (so->so_type) {
237 panic("uipc_rcvd DGRAM?");
241 if (unp->unp_conn == 0)
243 so2 = unp->unp_conn->unp_socket;
245 * Adjust backpressure on sender
246 * and wakeup any waiting to write.
248 so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt;
249 unp->unp_mbcnt = so->so_rcv.sb_mbcnt;
250 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc -
252 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
253 newhiwat, RLIM_INFINITY);
254 unp->unp_cc = so->so_rcv.sb_cc;
259 panic("uipc_rcvd unknown socktype");
264 /* pru_rcvoob is EOPNOTSUPP */
267 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
268 struct mbuf *control, struct thread *td)
271 struct unpcb *unp = sotounpcb(so);
279 if (flags & PRUS_OOB) {
284 if (control && (error = unp_internalize(control, td)))
287 switch (so->so_type) {
290 struct sockaddr *from;
297 error = unp_connect(so, nam, td);
301 if (unp->unp_conn == 0) {
306 so2 = unp->unp_conn->unp_socket;
308 from = (struct sockaddr *)unp->unp_addr;
311 if (sbappendaddr(&so2->so_rcv, from, m, control)) {
323 /* Connect if not connected yet. */
325 * Note: A better implementation would complain
326 * if not equal to the peer's address.
328 if ((so->so_state & SS_ISCONNECTED) == 0) {
330 error = unp_connect(so, nam, td);
339 if (so->so_state & SS_CANTSENDMORE) {
343 if (unp->unp_conn == 0)
344 panic("uipc_send connected but no connection?");
345 so2 = unp->unp_conn->unp_socket;
347 * Send to paired receive port, and then reduce
348 * send buffer hiwater marks to maintain backpressure.
352 if (sbappendcontrol(&so2->so_rcv, m, control))
355 sbappend(&so2->so_rcv, m);
356 so->so_snd.sb_mbmax -=
357 so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt;
358 unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt;
359 newhiwat = so->so_snd.sb_hiwat -
360 (so2->so_rcv.sb_cc - unp->unp_conn->unp_cc);
361 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
362 newhiwat, RLIM_INFINITY);
363 unp->unp_conn->unp_cc = so2->so_rcv.sb_cc;
369 panic("uipc_send unknown socktype");
373 * SEND_EOF is equivalent to a SEND followed by
376 if (flags & PRUS_EOF) {
381 if (control && error != 0)
382 unp_dispose(control);
393 uipc_sense(struct socket *so, struct stat *sb)
395 struct unpcb *unp = sotounpcb(so);
400 sb->st_blksize = so->so_snd.sb_hiwat;
401 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) {
402 so2 = unp->unp_conn->unp_socket;
403 sb->st_blksize += so2->so_rcv.sb_cc;
406 if (unp->unp_ino == 0) /* make up a non-zero inode number */
407 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
408 sb->st_ino = unp->unp_ino;
413 uipc_shutdown(struct socket *so)
415 struct unpcb *unp = sotounpcb(so);
425 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
427 struct unpcb *unp = sotounpcb(so);
432 *nam = dup_sockaddr((struct sockaddr *)unp->unp_addr);
436 struct pr_usrreqs uipc_usrreqs = {
437 uipc_abort, uipc_accept, uipc_attach, uipc_bind, uipc_connect,
438 uipc_connect2, pru_control_notsupp, uipc_detach, uipc_disconnect,
439 uipc_listen, uipc_peeraddr, uipc_rcvd, pru_rcvoob_notsupp,
440 uipc_send, uipc_sense, uipc_shutdown, uipc_sockaddr,
441 sosend, soreceive, sopoll
445 uipc_ctloutput(so, sopt)
447 struct sockopt *sopt;
449 struct unpcb *unp = sotounpcb(so);
452 switch (sopt->sopt_dir) {
454 switch (sopt->sopt_name) {
456 if (unp->unp_flags & UNP_HAVEPC)
457 error = sooptcopyout(sopt, &unp->unp_peercred,
458 sizeof(unp->unp_peercred));
460 if (so->so_type == SOCK_STREAM)
480 * Both send and receive buffers are allocated PIPSIZ bytes of buffering
481 * for stream sockets, although the total for sender and receiver is
482 * actually only PIPSIZ.
483 * Datagram sockets really use the sendspace as the maximum datagram size,
484 * and don't really want to reserve the sendspace. Their recvspace should
485 * be large enough for at least one max-size datagram plus address.
490 static u_long unpst_sendspace = PIPSIZ;
491 static u_long unpst_recvspace = PIPSIZ;
492 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */
493 static u_long unpdg_recvspace = 4*1024;
495 static int unp_rights; /* file descriptors in flight */
497 SYSCTL_DECL(_net_local_stream);
498 SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
499 &unpst_sendspace, 0, "");
500 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
501 &unpst_recvspace, 0, "");
502 SYSCTL_DECL(_net_local_dgram);
503 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
504 &unpdg_sendspace, 0, "");
505 SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
506 &unpdg_recvspace, 0, "");
507 SYSCTL_DECL(_net_local);
508 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, "");
511 unp_attach(struct socket *so, struct pru_attach_info *ai)
516 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
517 switch (so->so_type) {
520 error = soreserve(so, unpst_sendspace, unpst_recvspace,
525 error = soreserve(so, unpdg_sendspace, unpdg_recvspace,
535 unp = zalloc(unp_zone);
538 bzero(unp, sizeof *unp);
539 unp->unp_gencnt = ++unp_gencnt;
541 LIST_INIT(&unp->unp_refs);
542 unp->unp_socket = so;
543 unp->unp_rvnode = ai->fd_rdir; /* jail cruft XXX JH */
544 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead
545 : &unp_shead, unp, unp_link);
546 so->so_pcb = (caddr_t)unp;
554 LIST_REMOVE(unp, unp_link);
555 unp->unp_gencnt = ++unp_gencnt;
557 if (unp->unp_vnode) {
558 unp->unp_vnode->v_socket = 0;
559 vrele(unp->unp_vnode);
564 while (!LIST_EMPTY(&unp->unp_refs))
565 unp_drop(LIST_FIRST(&unp->unp_refs), ECONNRESET);
566 soisdisconnected(unp->unp_socket);
567 unp->unp_socket->so_pcb = 0;
570 * Normally the receive buffer is flushed later,
571 * in sofree, but if our receive buffer holds references
572 * to descriptors that are now garbage, we will dispose
573 * of those descriptor references after the garbage collector
574 * gets them (resulting in a "panic: closef: count < 0").
576 sorflush(unp->unp_socket);
580 FREE(unp->unp_addr, M_SONAME);
581 zfree(unp_zone, unp);
585 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td)
587 struct proc *p = td->td_proc;
588 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
592 struct nlookupdata nd;
593 char buf[SOCK_MAXADDRLEN];
595 if (unp->unp_vnode != NULL)
597 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
600 strncpy(buf, soun->sun_path, namelen);
601 buf[namelen] = 0; /* null-terminate the string */
602 error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_LOCKVP|NLC_CREATE);
604 error = nlookup(&nd);
605 if (error == 0 && nd.nl_ncp->nc_vp != NULL)
611 vattr.va_type = VSOCK;
612 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask);
613 error = VOP_NCREATE(nd.nl_ncp, &vp, nd.nl_cred, &vattr);
615 vp->v_socket = unp->unp_socket;
617 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam);
618 VOP_UNLOCK(vp, 0, td);
626 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
628 struct proc *p = td->td_proc;
629 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
631 struct socket *so2, *so3;
632 struct unpcb *unp, *unp2, *unp3;
634 struct nlookupdata nd;
635 char buf[SOCK_MAXADDRLEN];
639 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
642 strncpy(buf, soun->sun_path, len);
646 error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_FOLLOW);
648 error = nlookup(&nd);
650 error = cache_vget(nd.nl_ncp, nd.nl_cred, LK_EXCLUSIVE, &vp);
655 if (vp->v_type != VSOCK) {
659 error = VOP_ACCESS(vp, VWRITE, p->p_ucred, td);
664 error = ECONNREFUSED;
667 if (so->so_type != so2->so_type) {
671 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
672 if ((so2->so_options & SO_ACCEPTCONN) == 0 ||
673 (so3 = sonewconn(so2, 0)) == 0) {
674 error = ECONNREFUSED;
678 unp2 = sotounpcb(so2);
679 unp3 = sotounpcb(so3);
681 unp3->unp_addr = (struct sockaddr_un *)
682 dup_sockaddr((struct sockaddr *)unp2->unp_addr);
685 * unp_peercred management:
687 * The connecter's (client's) credentials are copied
688 * from its process structure at the time of connect()
691 cru2x(p->p_ucred, &unp3->unp_peercred);
692 unp3->unp_flags |= UNP_HAVEPC;
694 * The receiver's (server's) credentials are copied
695 * from the unp_peercred member of socket on which the
696 * former called listen(); unp_listen() cached that
697 * process's credentials at that time so we can use
700 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
701 ("unp_connect: listener without cached peercred"));
702 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
703 sizeof(unp->unp_peercred));
704 unp->unp_flags |= UNP_HAVEPC;
708 error = unp_connect2(so, so2);
715 unp_connect2(so, so2)
719 struct unpcb *unp = sotounpcb(so);
722 if (so2->so_type != so->so_type)
724 unp2 = sotounpcb(so2);
725 unp->unp_conn = unp2;
726 switch (so->so_type) {
729 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
734 unp2->unp_conn = unp;
740 panic("unp_connect2");
749 struct unpcb *unp2 = unp->unp_conn;
754 switch (unp->unp_socket->so_type) {
757 LIST_REMOVE(unp, unp_reflink);
758 unp->unp_socket->so_state &= ~SS_ISCONNECTED;
762 soisdisconnected(unp->unp_socket);
764 soisdisconnected(unp2->unp_socket);
780 prison_unpcb(struct thread *td, struct unpcb *unp)
786 if ((p = td->td_proc) == NULL)
788 if (!p->p_ucred->cr_prison)
790 if (p->p_fd->fd_rdir == unp->unp_rvnode)
796 unp_pcblist(SYSCTL_HANDLER_ARGS)
799 struct unpcb *unp, **unp_list;
801 struct unp_head *head;
803 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
805 KKASSERT(curproc != NULL);
808 * The process of preparing the PCB list is too time-consuming and
809 * resource-intensive to repeat twice on every request.
811 if (req->oldptr == 0) {
813 req->oldidx = (n + n/8) * sizeof(struct xunpcb);
817 if (req->newptr != 0)
821 * OK, now we're committed to doing something.
826 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
830 for (unp = LIST_FIRST(head), i = 0; unp && i < n;
831 unp = LIST_NEXT(unp, unp_link)) {
832 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->td, unp))
835 n = i; /* in case we lost some during malloc */
838 for (i = 0; i < n; i++) {
840 if (unp->unp_gencnt <= gencnt) {
842 xu.xu_len = sizeof xu;
845 * XXX - need more locking here to protect against
846 * connect/disconnect races for SMP.
849 bcopy(unp->unp_addr, &xu.xu_addr,
850 unp->unp_addr->sun_len);
851 if (unp->unp_conn && unp->unp_conn->unp_addr)
852 bcopy(unp->unp_conn->unp_addr,
854 unp->unp_conn->unp_addr->sun_len);
855 bcopy(unp, &xu.xu_unp, sizeof *unp);
856 sotoxsocket(unp->unp_socket, &xu.xu_socket);
857 error = SYSCTL_OUT(req, &xu, sizeof xu);
860 free(unp_list, M_TEMP);
864 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
865 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
866 "List of active local datagram sockets");
867 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
868 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
869 "List of active local stream sockets");
877 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn &&
878 (so = unp->unp_conn->unp_socket))
887 struct socket *so = unp->unp_socket;
889 so->so_error = errno;
902 unp_externalize(struct mbuf *rights)
904 struct proc *p = curproc; /* XXX */
906 struct cmsghdr *cm = mtod(rights, struct cmsghdr *);
910 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm))
911 / sizeof (struct file *);
915 * if the new FD's will not fit, then we free them all
917 if (!fdavail(p, newfds)) {
918 rp = (struct file **)CMSG_DATA(cm);
919 for (i = 0; i < newfds; i++) {
922 * zero the pointer before calling unp_discard,
923 * since it may end up in unp_gc()..
931 * now change each pointer to an fd in the global table to
932 * an integer that is the index to the local fd table entry
933 * that we set up to point to the global one we are transferring.
934 * If sizeof (struct file *) is bigger than or equal to sizeof int,
935 * then do it in forward order. In that case, an integer will
936 * always come in the same place or before its corresponding
937 * struct file pointer.
938 * If sizeof (struct file *) is smaller than sizeof int, then
939 * do it in reverse order.
941 if (sizeof (struct file *) >= sizeof (int)) {
942 fdp = (int *)(cm + 1);
943 rp = (struct file **)CMSG_DATA(cm);
944 for (i = 0; i < newfds; i++) {
945 if (fdalloc(p, 0, &f))
946 panic("unp_externalize");
948 p->p_fd->fd_ofiles[f] = fp;
954 fdp = (int *)(cm + 1) + newfds - 1;
955 rp = (struct file **)CMSG_DATA(cm) + newfds - 1;
956 for (i = 0; i < newfds; i++) {
957 if (fdalloc(p, 0, &f))
958 panic("unp_externalize");
960 p->p_fd->fd_ofiles[f] = fp;
968 * Adjust length, in case sizeof(struct file *) and sizeof(int)
971 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int));
972 rights->m_len = cm->cmsg_len;
979 unp_zone = zinit("unpcb", sizeof(struct unpcb), nmbclusters, 0, 0);
982 LIST_INIT(&unp_dhead);
983 LIST_INIT(&unp_shead);
987 unp_internalize(struct mbuf *control, struct thread *td)
989 struct proc *p = td->td_proc;
990 struct filedesc *fdescp;
991 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
995 struct cmsgcred *cmcred;
1001 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) ||
1002 cm->cmsg_level != SOL_SOCKET || cm->cmsg_len != control->m_len)
1006 * Fill in credential information.
1008 if (cm->cmsg_type == SCM_CREDS) {
1009 cmcred = (struct cmsgcred *)(cm + 1);
1010 cmcred->cmcred_pid = p->p_pid;
1011 cmcred->cmcred_uid = p->p_ucred->cr_ruid;
1012 cmcred->cmcred_gid = p->p_ucred->cr_rgid;
1013 cmcred->cmcred_euid = p->p_ucred->cr_uid;
1014 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups,
1016 for (i = 0; i < cmcred->cmcred_ngroups; i++)
1017 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i];
1021 oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int);
1023 * check that all the FDs passed in refer to legal OPEN files
1024 * If not, reject the entire operation.
1026 fdp = (int *)(cm + 1);
1027 for (i = 0; i < oldfds; i++) {
1029 if ((unsigned)fd >= fdescp->fd_nfiles ||
1030 fdescp->fd_ofiles[fd] == NULL)
1032 if (fdescp->fd_ofiles[fd]->f_type == DTYPE_KQUEUE)
1033 return (EOPNOTSUPP);
1036 * Now replace the integer FDs with pointers to
1037 * the associated global file table entry..
1038 * Allocate a bigger buffer as necessary. But if an cluster is not
1039 * enough, return E2BIG.
1041 newlen = CMSG_LEN(oldfds * sizeof(struct file *));
1042 if (newlen > MCLBYTES)
1044 if (newlen - control->m_len > M_TRAILINGSPACE(control)) {
1045 if (control->m_flags & M_EXT)
1047 MCLGET(control, MB_WAIT);
1048 if ((control->m_flags & M_EXT) == 0)
1051 /* copy the data to the cluster */
1052 memcpy(mtod(control, char *), cm, cm->cmsg_len);
1053 cm = mtod(control, struct cmsghdr *);
1057 * Adjust length, in case sizeof(struct file *) and sizeof(int)
1060 control->m_len = cm->cmsg_len = newlen;
1063 * Transform the file descriptors into struct file pointers.
1064 * If sizeof (struct file *) is bigger than or equal to sizeof int,
1065 * then do it in reverse order so that the int won't get until
1067 * If sizeof (struct file *) is smaller than sizeof int, then
1068 * do it in forward order.
1070 if (sizeof (struct file *) >= sizeof (int)) {
1071 fdp = (int *)(cm + 1) + oldfds - 1;
1072 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1;
1073 for (i = 0; i < oldfds; i++) {
1074 fp = fdescp->fd_ofiles[*fdp--];
1081 fdp = (int *)(cm + 1);
1082 rp = (struct file **)CMSG_DATA(cm);
1083 for (i = 0; i < oldfds; i++) {
1084 fp = fdescp->fd_ofiles[*fdp++];
1094 static int unp_defer, unp_gcing;
1099 struct file *fp, *nextfp;
1101 struct file **extra_ref, **fpp;
1109 * before going through all this, set all FDs to
1110 * be NOT defered and NOT externally accessible
1112 LIST_FOREACH(fp, &filehead, f_list)
1113 fp->f_flag &= ~(FMARK|FDEFER);
1115 LIST_FOREACH(fp, &filehead, f_list) {
1117 * If the file is not open, skip it
1119 if (fp->f_count == 0)
1122 * If we already marked it as 'defer' in a
1123 * previous pass, then try process it this time
1126 if (fp->f_flag & FDEFER) {
1127 fp->f_flag &= ~FDEFER;
1131 * if it's not defered, then check if it's
1132 * already marked.. if so skip it
1134 if (fp->f_flag & FMARK)
1137 * If all references are from messages
1138 * in transit, then skip it. it's not
1139 * externally accessible.
1141 if (fp->f_count == fp->f_msgcount)
1144 * If it got this far then it must be
1145 * externally accessible.
1147 fp->f_flag |= FMARK;
1150 * either it was defered, or it is externally
1151 * accessible and not already marked so.
1152 * Now check if it is possibly one of OUR sockets.
1154 if (fp->f_type != DTYPE_SOCKET ||
1155 (so = (struct socket *)fp->f_data) == 0)
1157 if (so->so_proto->pr_domain != &localdomain ||
1158 (so->so_proto->pr_flags&PR_RIGHTS) == 0)
1161 if (so->so_rcv.sb_flags & SB_LOCK) {
1163 * This is problematical; it's not clear
1164 * we need to wait for the sockbuf to be
1165 * unlocked (on a uniprocessor, at least),
1166 * and it's also not clear what to do
1167 * if sbwait returns an error due to receipt
1168 * of a signal. If sbwait does return
1169 * an error, we'll go into an infinite
1170 * loop. Delete all of this for now.
1172 (void) sbwait(&so->so_rcv);
1177 * So, Ok, it's one of our sockets and it IS externally
1178 * accessible (or was defered). Now we look
1179 * to see if we hold any file descriptors in its
1180 * message buffers. Follow those links and mark them
1181 * as accessible too.
1183 unp_scan(so->so_rcv.sb_mb, unp_mark);
1185 } while (unp_defer);
1187 * We grab an extra reference to each of the file table entries
1188 * that are not otherwise accessible and then free the rights
1189 * that are stored in messages on them.
1191 * The bug in the orginal code is a little tricky, so I'll describe
1192 * what's wrong with it here.
1194 * It is incorrect to simply unp_discard each entry for f_msgcount
1195 * times -- consider the case of sockets A and B that contain
1196 * references to each other. On a last close of some other socket,
1197 * we trigger a gc since the number of outstanding rights (unp_rights)
1198 * is non-zero. If during the sweep phase the gc code un_discards,
1199 * we end up doing a (full) closef on the descriptor. A closef on A
1200 * results in the following chain. Closef calls soo_close, which
1201 * calls soclose. Soclose calls first (through the switch
1202 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply
1203 * returns because the previous instance had set unp_gcing, and
1204 * we return all the way back to soclose, which marks the socket
1205 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush
1206 * to free up the rights that are queued in messages on the socket A,
1207 * i.e., the reference on B. The sorflush calls via the dom_dispose
1208 * switch unp_dispose, which unp_scans with unp_discard. This second
1209 * instance of unp_discard just calls closef on B.
1211 * Well, a similar chain occurs on B, resulting in a sorflush on B,
1212 * which results in another closef on A. Unfortunately, A is already
1213 * being closed, and the descriptor has already been marked with
1214 * SS_NOFDREF, and soclose panics at this point.
1216 * Here, we first take an extra reference to each inaccessible
1217 * descriptor. Then, we call sorflush ourself, since we know
1218 * it is a Unix domain socket anyhow. After we destroy all the
1219 * rights carried in messages, we do a last closef to get rid
1220 * of our extra reference. This is the last close, and the
1221 * unp_detach etc will shut down the socket.
1223 * 91/09/19, bsy@cs.cmu.edu
1225 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK);
1226 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; fp != 0;
1228 nextfp = LIST_NEXT(fp, f_list);
1230 * If it's not open, skip it
1232 if (fp->f_count == 0)
1235 * If all refs are from msgs, and it's not marked accessible
1236 * then it must be referenced from some unreachable cycle
1237 * of (shut-down) FDs, so include it in our
1238 * list of FDs to remove
1240 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) {
1247 * for each FD on our hit list, do the following two things
1249 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) {
1250 struct file *tfp = *fpp;
1251 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL)
1252 sorflush((struct socket *)(tfp->f_data));
1254 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp)
1256 free((caddr_t)extra_ref, M_FILE);
1261 unp_dispose(struct mbuf *m)
1264 unp_scan(m, unp_discard);
1268 unp_listen(struct unpcb *unp, struct thread *td)
1270 struct proc *p = td->td_proc;
1273 cru2x(p->p_ucred, &unp->unp_peercred);
1274 unp->unp_flags |= UNP_HAVEPCCACHED;
1281 void (*op) (struct file *);
1290 for (m = m0; m; m = m->m_next)
1291 if (m->m_type == MT_CONTROL &&
1292 m->m_len >= sizeof(*cm)) {
1293 cm = mtod(m, struct cmsghdr *);
1294 if (cm->cmsg_level != SOL_SOCKET ||
1295 cm->cmsg_type != SCM_RIGHTS)
1297 qfds = (cm->cmsg_len -
1298 (CMSG_DATA(cm) - (u_char *)cm))
1299 / sizeof (struct file *);
1300 rp = (struct file **)CMSG_DATA(cm);
1301 for (i = 0; i < qfds; i++)
1303 break; /* XXX, but saves time */
1314 if (fp->f_flag & FMARK)
1317 fp->f_flag |= (FMARK|FDEFER);
1327 (void) closef(fp, NULL);