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 1.15 2004/06/06 19:16:06 dillon 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/namei.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
52 #include <sys/resourcevar.h>
54 #include <sys/sysctl.h>
56 #include <sys/unpcb.h>
57 #include <sys/vnode.h>
58 #include <sys/file2.h>
60 #include <vm/vm_zone.h>
62 static struct vm_zone *unp_zone;
63 static unp_gen_t unp_gencnt;
64 static u_int unp_count;
66 static struct unp_head unp_shead, unp_dhead;
69 * Unix communications domain.
73 * rethink name space problems
74 * need a proper out-of-band
77 static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
78 static ino_t unp_ino; /* prototype for fake inode numbers */
80 static int unp_attach (struct socket *, struct pru_attach_info *);
81 static void unp_detach (struct unpcb *);
82 static int unp_bind (struct unpcb *,struct sockaddr *, struct thread *);
83 static int unp_connect (struct socket *,struct sockaddr *,
85 static void unp_disconnect (struct unpcb *);
86 static void unp_shutdown (struct unpcb *);
87 static void unp_drop (struct unpcb *, int);
88 static void unp_gc (void);
89 static void unp_scan (struct mbuf *, void (*)(struct file *));
90 static void unp_mark (struct file *);
91 static void unp_discard (struct file *);
92 static int unp_internalize (struct mbuf *, struct thread *);
93 static int unp_listen (struct unpcb *, struct thread *);
96 uipc_abort(struct socket *so)
98 struct unpcb *unp = sotounpcb(so);
102 unp_drop(unp, ECONNABORTED);
109 uipc_accept(struct socket *so, struct sockaddr **nam)
111 struct unpcb *unp = sotounpcb(so);
117 * Pass back name of connected socket,
118 * if it was bound and we are still connected
119 * (our peer may have closed already!).
121 if (unp->unp_conn && unp->unp_conn->unp_addr) {
122 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr);
124 *nam = dup_sockaddr((struct sockaddr *)&sun_noname);
130 uipc_attach(struct socket *so, int proto, struct pru_attach_info *ai)
132 struct unpcb *unp = sotounpcb(so);
136 return unp_attach(so, ai);
140 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
142 struct unpcb *unp = sotounpcb(so);
146 return unp_bind(unp, nam, td);
150 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
152 struct unpcb *unp = sotounpcb(so);
156 return unp_connect(so, nam, td);
160 uipc_connect2(struct socket *so1, struct socket *so2)
162 struct unpcb *unp = sotounpcb(so1);
167 return unp_connect2(so1, so2);
170 /* control is EOPNOTSUPP */
173 uipc_detach(struct socket *so)
175 struct unpcb *unp = sotounpcb(so);
185 uipc_disconnect(struct socket *so)
187 struct unpcb *unp = sotounpcb(so);
196 uipc_listen(struct socket *so, struct thread *td)
198 struct unpcb *unp = sotounpcb(so);
200 if (unp == 0 || unp->unp_vnode == 0)
202 return unp_listen(unp, td);
206 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
208 struct unpcb *unp = sotounpcb(so);
212 if (unp->unp_conn && unp->unp_conn->unp_addr)
213 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr);
216 * XXX: It seems that this test always fails even when
217 * connection is established. So, this else clause is
218 * added as workaround to return PF_LOCAL sockaddr.
220 *nam = dup_sockaddr((struct sockaddr *)&sun_noname);
226 uipc_rcvd(struct socket *so, int flags)
228 struct unpcb *unp = sotounpcb(so);
234 switch (so->so_type) {
236 panic("uipc_rcvd DGRAM?");
240 if (unp->unp_conn == 0)
242 so2 = unp->unp_conn->unp_socket;
244 * Adjust backpressure on sender
245 * and wakeup any waiting to write.
247 so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt;
248 unp->unp_mbcnt = so->so_rcv.sb_mbcnt;
249 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc -
251 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
252 newhiwat, RLIM_INFINITY);
253 unp->unp_cc = so->so_rcv.sb_cc;
258 panic("uipc_rcvd unknown socktype");
263 /* pru_rcvoob is EOPNOTSUPP */
266 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
267 struct mbuf *control, struct thread *td)
270 struct unpcb *unp = sotounpcb(so);
278 if (flags & PRUS_OOB) {
283 if (control && (error = unp_internalize(control, td)))
286 switch (so->so_type) {
289 struct sockaddr *from;
296 error = unp_connect(so, nam, td);
300 if (unp->unp_conn == 0) {
305 so2 = unp->unp_conn->unp_socket;
307 from = (struct sockaddr *)unp->unp_addr;
310 if (sbappendaddr(&so2->so_rcv, from, m, control)) {
322 /* Connect if not connected yet. */
324 * Note: A better implementation would complain
325 * if not equal to the peer's address.
327 if ((so->so_state & SS_ISCONNECTED) == 0) {
329 error = unp_connect(so, nam, td);
338 if (so->so_state & SS_CANTSENDMORE) {
342 if (unp->unp_conn == 0)
343 panic("uipc_send connected but no connection?");
344 so2 = unp->unp_conn->unp_socket;
346 * Send to paired receive port, and then reduce
347 * send buffer hiwater marks to maintain backpressure.
351 if (sbappendcontrol(&so2->so_rcv, m, control))
354 sbappend(&so2->so_rcv, m);
355 so->so_snd.sb_mbmax -=
356 so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt;
357 unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt;
358 newhiwat = so->so_snd.sb_hiwat -
359 (so2->so_rcv.sb_cc - unp->unp_conn->unp_cc);
360 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
361 newhiwat, RLIM_INFINITY);
362 unp->unp_conn->unp_cc = so2->so_rcv.sb_cc;
368 panic("uipc_send unknown socktype");
372 * SEND_EOF is equivalent to a SEND followed by
375 if (flags & PRUS_EOF) {
380 if (control && error != 0)
381 unp_dispose(control);
392 uipc_sense(struct socket *so, struct stat *sb)
394 struct unpcb *unp = sotounpcb(so);
399 sb->st_blksize = so->so_snd.sb_hiwat;
400 if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) {
401 so2 = unp->unp_conn->unp_socket;
402 sb->st_blksize += so2->so_rcv.sb_cc;
405 if (unp->unp_ino == 0) /* make up a non-zero inode number */
406 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
407 sb->st_ino = unp->unp_ino;
412 uipc_shutdown(struct socket *so)
414 struct unpcb *unp = sotounpcb(so);
424 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
426 struct unpcb *unp = sotounpcb(so);
431 *nam = dup_sockaddr((struct sockaddr *)unp->unp_addr);
435 struct pr_usrreqs uipc_usrreqs = {
436 uipc_abort, uipc_accept, uipc_attach, uipc_bind, uipc_connect,
437 uipc_connect2, pru_control_notsupp, uipc_detach, uipc_disconnect,
438 uipc_listen, uipc_peeraddr, uipc_rcvd, pru_rcvoob_notsupp,
439 uipc_send, uipc_sense, uipc_shutdown, uipc_sockaddr,
440 sosend, soreceive, sopoll
444 uipc_ctloutput(so, sopt)
446 struct sockopt *sopt;
448 struct unpcb *unp = sotounpcb(so);
451 switch (sopt->sopt_dir) {
453 switch (sopt->sopt_name) {
455 if (unp->unp_flags & UNP_HAVEPC)
456 error = sooptcopyout(sopt, &unp->unp_peercred,
457 sizeof(unp->unp_peercred));
459 if (so->so_type == SOCK_STREAM)
479 * Both send and receive buffers are allocated PIPSIZ bytes of buffering
480 * for stream sockets, although the total for sender and receiver is
481 * actually only PIPSIZ.
482 * Datagram sockets really use the sendspace as the maximum datagram size,
483 * and don't really want to reserve the sendspace. Their recvspace should
484 * be large enough for at least one max-size datagram plus address.
489 static u_long unpst_sendspace = PIPSIZ;
490 static u_long unpst_recvspace = PIPSIZ;
491 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */
492 static u_long unpdg_recvspace = 4*1024;
494 static int unp_rights; /* file descriptors in flight */
496 SYSCTL_DECL(_net_local_stream);
497 SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
498 &unpst_sendspace, 0, "");
499 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
500 &unpst_recvspace, 0, "");
501 SYSCTL_DECL(_net_local_dgram);
502 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
503 &unpdg_sendspace, 0, "");
504 SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
505 &unpdg_recvspace, 0, "");
506 SYSCTL_DECL(_net_local);
507 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, "");
510 unp_attach(struct socket *so, struct pru_attach_info *ai)
515 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
516 switch (so->so_type) {
519 error = soreserve(so, unpst_sendspace, unpst_recvspace,
524 error = soreserve(so, unpdg_sendspace, unpdg_recvspace,
534 unp = zalloc(unp_zone);
537 bzero(unp, sizeof *unp);
538 unp->unp_gencnt = ++unp_gencnt;
540 LIST_INIT(&unp->unp_refs);
541 unp->unp_socket = so;
542 unp->unp_rvnode = ai->fd_rdir; /* jail cruft XXX JH */
543 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead
544 : &unp_shead, unp, unp_link);
545 so->so_pcb = (caddr_t)unp;
553 LIST_REMOVE(unp, unp_link);
554 unp->unp_gencnt = ++unp_gencnt;
556 if (unp->unp_vnode) {
557 unp->unp_vnode->v_socket = 0;
558 vrele(unp->unp_vnode);
563 while (!LIST_EMPTY(&unp->unp_refs))
564 unp_drop(LIST_FIRST(&unp->unp_refs), ECONNRESET);
565 soisdisconnected(unp->unp_socket);
566 unp->unp_socket->so_pcb = 0;
569 * Normally the receive buffer is flushed later,
570 * in sofree, but if our receive buffer holds references
571 * to descriptors that are now garbage, we will dispose
572 * of those descriptor references after the garbage collector
573 * gets them (resulting in a "panic: closef: count < 0").
575 sorflush(unp->unp_socket);
579 FREE(unp->unp_addr, M_SONAME);
580 zfree(unp_zone, unp);
584 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td)
586 struct proc *p = td->td_proc;
587 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
592 char buf[SOCK_MAXADDRLEN];
594 if (unp->unp_vnode != NULL)
596 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
599 strncpy(buf, soun->sun_path, namelen);
600 buf[namelen] = 0; /* null-terminate the string */
601 NDINIT(&nd, NAMEI_CREATE, CNP_LOCKPARENT, UIO_SYSSPACE, buf, td);
602 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
608 NDFREE(&nd, NDF_ONLY_PNBUF);
617 vattr.va_type = VSOCK;
618 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask);
619 VOP_LEASE(nd.ni_dvp, td, p->p_ucred, LEASE_WRITE);
620 error = VOP_CREATE(nd.ni_dvp, NCPNULL, &nd.ni_vp, &nd.ni_cnd, &vattr);
621 NDFREE(&nd, NDF_ONLY_PNBUF);
626 vp->v_socket = unp->unp_socket;
628 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam);
629 VOP_UNLOCK(vp, NULL, 0, td);
634 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
636 struct proc *p = td->td_proc;
637 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
639 struct socket *so2, *so3;
640 struct unpcb *unp, *unp2, *unp3;
643 char buf[SOCK_MAXADDRLEN];
647 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
650 strncpy(buf, soun->sun_path, len);
653 NDINIT(&nd, NAMEI_LOOKUP, CNP_FOLLOW | CNP_LOCKLEAF,
654 UIO_SYSSPACE, buf, td);
659 NDFREE(&nd, NDF_ONLY_PNBUF);
660 if (vp->v_type != VSOCK) {
664 error = VOP_ACCESS(vp, VWRITE, p->p_ucred, td);
669 error = ECONNREFUSED;
672 if (so->so_type != so2->so_type) {
676 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
677 if ((so2->so_options & SO_ACCEPTCONN) == 0 ||
678 (so3 = sonewconn(so2, 0)) == 0) {
679 error = ECONNREFUSED;
683 unp2 = sotounpcb(so2);
684 unp3 = sotounpcb(so3);
686 unp3->unp_addr = (struct sockaddr_un *)
687 dup_sockaddr((struct sockaddr *)unp2->unp_addr);
690 * unp_peercred management:
692 * The connecter's (client's) credentials are copied
693 * from its process structure at the time of connect()
696 cru2x(p->p_ucred, &unp3->unp_peercred);
697 unp3->unp_flags |= UNP_HAVEPC;
699 * The receiver's (server's) credentials are copied
700 * from the unp_peercred member of socket on which the
701 * former called listen(); unp_listen() cached that
702 * process's credentials at that time so we can use
705 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
706 ("unp_connect: listener without cached peercred"));
707 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
708 sizeof(unp->unp_peercred));
709 unp->unp_flags |= UNP_HAVEPC;
713 error = unp_connect2(so, so2);
720 unp_connect2(so, so2)
724 struct unpcb *unp = sotounpcb(so);
727 if (so2->so_type != so->so_type)
729 unp2 = sotounpcb(so2);
730 unp->unp_conn = unp2;
731 switch (so->so_type) {
734 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
739 unp2->unp_conn = unp;
745 panic("unp_connect2");
754 struct unpcb *unp2 = unp->unp_conn;
759 switch (unp->unp_socket->so_type) {
762 LIST_REMOVE(unp, unp_reflink);
763 unp->unp_socket->so_state &= ~SS_ISCONNECTED;
767 soisdisconnected(unp->unp_socket);
769 soisdisconnected(unp2->unp_socket);
785 prison_unpcb(struct thread *td, struct unpcb *unp)
791 if ((p = td->td_proc) == NULL)
793 if (!p->p_ucred->cr_prison)
795 if (p->p_fd->fd_rdir == unp->unp_rvnode)
801 unp_pcblist(SYSCTL_HANDLER_ARGS)
804 struct unpcb *unp, **unp_list;
807 struct unp_head *head;
809 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
811 KKASSERT(curproc != NULL);
814 * The process of preparing the PCB list is too time-consuming and
815 * resource-intensive to repeat twice on every request.
817 if (req->oldptr == 0) {
819 req->oldidx = 2 * (sizeof xug)
820 + (n + n/8) * sizeof(struct xunpcb);
824 if (req->newptr != 0)
828 * OK, now we're committed to doing something.
833 xug.xug_len = sizeof xug;
835 xug.xug_gen = gencnt;
836 xug.xug_sogen = so_gencnt;
837 error = SYSCTL_OUT(req, &xug, sizeof xug);
841 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
845 for (unp = LIST_FIRST(head), i = 0; unp && i < n;
846 unp = LIST_NEXT(unp, unp_link)) {
847 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->td, unp))
850 n = i; /* in case we lost some during malloc */
853 for (i = 0; i < n; i++) {
855 if (unp->unp_gencnt <= gencnt) {
857 xu.xu_len = sizeof xu;
860 * XXX - need more locking here to protect against
861 * connect/disconnect races for SMP.
864 bcopy(unp->unp_addr, &xu.xu_addr,
865 unp->unp_addr->sun_len);
866 if (unp->unp_conn && unp->unp_conn->unp_addr)
867 bcopy(unp->unp_conn->unp_addr,
869 unp->unp_conn->unp_addr->sun_len);
870 bcopy(unp, &xu.xu_unp, sizeof *unp);
871 sotoxsocket(unp->unp_socket, &xu.xu_socket);
872 error = SYSCTL_OUT(req, &xu, sizeof xu);
877 * Give the user an updated idea of our state.
878 * If the generation differs from what we told
879 * her before, she knows that something happened
880 * while we were processing this request, and it
881 * might be necessary to retry.
883 xug.xug_gen = unp_gencnt;
884 xug.xug_sogen = so_gencnt;
885 xug.xug_count = unp_count;
886 error = SYSCTL_OUT(req, &xug, sizeof xug);
888 free(unp_list, M_TEMP);
892 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
893 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
894 "List of active local datagram sockets");
895 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
896 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
897 "List of active local stream sockets");
905 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn &&
906 (so = unp->unp_conn->unp_socket))
915 struct socket *so = unp->unp_socket;
917 so->so_error = errno;
930 unp_externalize(struct mbuf *rights)
932 struct proc *p = curproc; /* XXX */
934 struct cmsghdr *cm = mtod(rights, struct cmsghdr *);
938 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm))
939 / sizeof (struct file *);
943 * if the new FD's will not fit, then we free them all
945 if (!fdavail(p, newfds)) {
946 rp = (struct file **)CMSG_DATA(cm);
947 for (i = 0; i < newfds; i++) {
950 * zero the pointer before calling unp_discard,
951 * since it may end up in unp_gc()..
959 * now change each pointer to an fd in the global table to
960 * an integer that is the index to the local fd table entry
961 * that we set up to point to the global one we are transferring.
962 * If sizeof (struct file *) is bigger than or equal to sizeof int,
963 * then do it in forward order. In that case, an integer will
964 * always come in the same place or before its corresponding
965 * struct file pointer.
966 * If sizeof (struct file *) is smaller than sizeof int, then
967 * do it in reverse order.
969 if (sizeof (struct file *) >= sizeof (int)) {
970 fdp = (int *)(cm + 1);
971 rp = (struct file **)CMSG_DATA(cm);
972 for (i = 0; i < newfds; i++) {
973 if (fdalloc(p, 0, &f))
974 panic("unp_externalize");
976 p->p_fd->fd_ofiles[f] = fp;
982 fdp = (int *)(cm + 1) + newfds - 1;
983 rp = (struct file **)CMSG_DATA(cm) + newfds - 1;
984 for (i = 0; i < newfds; i++) {
985 if (fdalloc(p, 0, &f))
986 panic("unp_externalize");
988 p->p_fd->fd_ofiles[f] = fp;
996 * Adjust length, in case sizeof(struct file *) and sizeof(int)
999 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int));
1000 rights->m_len = cm->cmsg_len;
1007 unp_zone = zinit("unpcb", sizeof(struct unpcb), nmbclusters, 0, 0);
1010 LIST_INIT(&unp_dhead);
1011 LIST_INIT(&unp_shead);
1015 unp_internalize(struct mbuf *control, struct thread *td)
1017 struct proc *p = td->td_proc;
1018 struct filedesc *fdescp;
1019 struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1023 struct cmsgcred *cmcred;
1029 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) ||
1030 cm->cmsg_level != SOL_SOCKET || cm->cmsg_len != control->m_len)
1034 * Fill in credential information.
1036 if (cm->cmsg_type == SCM_CREDS) {
1037 cmcred = (struct cmsgcred *)(cm + 1);
1038 cmcred->cmcred_pid = p->p_pid;
1039 cmcred->cmcred_uid = p->p_ucred->cr_ruid;
1040 cmcred->cmcred_gid = p->p_ucred->cr_rgid;
1041 cmcred->cmcred_euid = p->p_ucred->cr_uid;
1042 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups,
1044 for (i = 0; i < cmcred->cmcred_ngroups; i++)
1045 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i];
1049 oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int);
1051 * check that all the FDs passed in refer to legal OPEN files
1052 * If not, reject the entire operation.
1054 fdp = (int *)(cm + 1);
1055 for (i = 0; i < oldfds; i++) {
1057 if ((unsigned)fd >= fdescp->fd_nfiles ||
1058 fdescp->fd_ofiles[fd] == NULL)
1060 if (fdescp->fd_ofiles[fd]->f_type == DTYPE_KQUEUE)
1061 return (EOPNOTSUPP);
1064 * Now replace the integer FDs with pointers to
1065 * the associated global file table entry..
1066 * Allocate a bigger buffer as necessary. But if an cluster is not
1067 * enough, return E2BIG.
1069 newlen = CMSG_LEN(oldfds * sizeof(struct file *));
1070 if (newlen > MCLBYTES)
1072 if (newlen - control->m_len > M_TRAILINGSPACE(control)) {
1073 if (control->m_flags & M_EXT)
1075 MCLGET(control, MB_WAIT);
1076 if ((control->m_flags & M_EXT) == 0)
1079 /* copy the data to the cluster */
1080 memcpy(mtod(control, char *), cm, cm->cmsg_len);
1081 cm = mtod(control, struct cmsghdr *);
1085 * Adjust length, in case sizeof(struct file *) and sizeof(int)
1088 control->m_len = cm->cmsg_len = newlen;
1091 * Transform the file descriptors into struct file pointers.
1092 * If sizeof (struct file *) is bigger than or equal to sizeof int,
1093 * then do it in reverse order so that the int won't get until
1095 * If sizeof (struct file *) is smaller than sizeof int, then
1096 * do it in forward order.
1098 if (sizeof (struct file *) >= sizeof (int)) {
1099 fdp = (int *)(cm + 1) + oldfds - 1;
1100 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1;
1101 for (i = 0; i < oldfds; i++) {
1102 fp = fdescp->fd_ofiles[*fdp--];
1109 fdp = (int *)(cm + 1);
1110 rp = (struct file **)CMSG_DATA(cm);
1111 for (i = 0; i < oldfds; i++) {
1112 fp = fdescp->fd_ofiles[*fdp++];
1122 static int unp_defer, unp_gcing;
1127 struct file *fp, *nextfp;
1129 struct file **extra_ref, **fpp;
1137 * before going through all this, set all FDs to
1138 * be NOT defered and NOT externally accessible
1140 LIST_FOREACH(fp, &filehead, f_list)
1141 fp->f_flag &= ~(FMARK|FDEFER);
1143 LIST_FOREACH(fp, &filehead, f_list) {
1145 * If the file is not open, skip it
1147 if (fp->f_count == 0)
1150 * If we already marked it as 'defer' in a
1151 * previous pass, then try process it this time
1154 if (fp->f_flag & FDEFER) {
1155 fp->f_flag &= ~FDEFER;
1159 * if it's not defered, then check if it's
1160 * already marked.. if so skip it
1162 if (fp->f_flag & FMARK)
1165 * If all references are from messages
1166 * in transit, then skip it. it's not
1167 * externally accessible.
1169 if (fp->f_count == fp->f_msgcount)
1172 * If it got this far then it must be
1173 * externally accessible.
1175 fp->f_flag |= FMARK;
1178 * either it was defered, or it is externally
1179 * accessible and not already marked so.
1180 * Now check if it is possibly one of OUR sockets.
1182 if (fp->f_type != DTYPE_SOCKET ||
1183 (so = (struct socket *)fp->f_data) == 0)
1185 if (so->so_proto->pr_domain != &localdomain ||
1186 (so->so_proto->pr_flags&PR_RIGHTS) == 0)
1189 if (so->so_rcv.sb_flags & SB_LOCK) {
1191 * This is problematical; it's not clear
1192 * we need to wait for the sockbuf to be
1193 * unlocked (on a uniprocessor, at least),
1194 * and it's also not clear what to do
1195 * if sbwait returns an error due to receipt
1196 * of a signal. If sbwait does return
1197 * an error, we'll go into an infinite
1198 * loop. Delete all of this for now.
1200 (void) sbwait(&so->so_rcv);
1205 * So, Ok, it's one of our sockets and it IS externally
1206 * accessible (or was defered). Now we look
1207 * to see if we hold any file descriptors in its
1208 * message buffers. Follow those links and mark them
1209 * as accessible too.
1211 unp_scan(so->so_rcv.sb_mb, unp_mark);
1213 } while (unp_defer);
1215 * We grab an extra reference to each of the file table entries
1216 * that are not otherwise accessible and then free the rights
1217 * that are stored in messages on them.
1219 * The bug in the orginal code is a little tricky, so I'll describe
1220 * what's wrong with it here.
1222 * It is incorrect to simply unp_discard each entry for f_msgcount
1223 * times -- consider the case of sockets A and B that contain
1224 * references to each other. On a last close of some other socket,
1225 * we trigger a gc since the number of outstanding rights (unp_rights)
1226 * is non-zero. If during the sweep phase the gc code un_discards,
1227 * we end up doing a (full) closef on the descriptor. A closef on A
1228 * results in the following chain. Closef calls soo_close, which
1229 * calls soclose. Soclose calls first (through the switch
1230 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply
1231 * returns because the previous instance had set unp_gcing, and
1232 * we return all the way back to soclose, which marks the socket
1233 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush
1234 * to free up the rights that are queued in messages on the socket A,
1235 * i.e., the reference on B. The sorflush calls via the dom_dispose
1236 * switch unp_dispose, which unp_scans with unp_discard. This second
1237 * instance of unp_discard just calls closef on B.
1239 * Well, a similar chain occurs on B, resulting in a sorflush on B,
1240 * which results in another closef on A. Unfortunately, A is already
1241 * being closed, and the descriptor has already been marked with
1242 * SS_NOFDREF, and soclose panics at this point.
1244 * Here, we first take an extra reference to each inaccessible
1245 * descriptor. Then, we call sorflush ourself, since we know
1246 * it is a Unix domain socket anyhow. After we destroy all the
1247 * rights carried in messages, we do a last closef to get rid
1248 * of our extra reference. This is the last close, and the
1249 * unp_detach etc will shut down the socket.
1251 * 91/09/19, bsy@cs.cmu.edu
1253 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK);
1254 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; fp != 0;
1256 nextfp = LIST_NEXT(fp, f_list);
1258 * If it's not open, skip it
1260 if (fp->f_count == 0)
1263 * If all refs are from msgs, and it's not marked accessible
1264 * then it must be referenced from some unreachable cycle
1265 * of (shut-down) FDs, so include it in our
1266 * list of FDs to remove
1268 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) {
1275 * for each FD on our hit list, do the following two things
1277 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) {
1278 struct file *tfp = *fpp;
1279 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL)
1280 sorflush((struct socket *)(tfp->f_data));
1282 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp)
1284 free((caddr_t)extra_ref, M_FILE);
1289 unp_dispose(struct mbuf *m)
1292 unp_scan(m, unp_discard);
1296 unp_listen(struct unpcb *unp, struct thread *td)
1298 struct proc *p = td->td_proc;
1301 cru2x(p->p_ucred, &unp->unp_peercred);
1302 unp->unp_flags |= UNP_HAVEPCCACHED;
1309 void (*op) (struct file *);
1318 for (m = m0; m; m = m->m_next)
1319 if (m->m_type == MT_CONTROL &&
1320 m->m_len >= sizeof(*cm)) {
1321 cm = mtod(m, struct cmsghdr *);
1322 if (cm->cmsg_level != SOL_SOCKET ||
1323 cm->cmsg_type != SCM_RIGHTS)
1325 qfds = (cm->cmsg_len -
1326 (CMSG_DATA(cm) - (u_char *)cm))
1327 / sizeof (struct file *);
1328 rp = (struct file **)CMSG_DATA(cm);
1329 for (i = 0; i < qfds; i++)
1331 break; /* XXX, but saves time */
1342 if (fp->f_flag & FMARK)
1345 fp->f_flag |= (FMARK|FDEFER);
1355 (void) closef(fp, NULL);