2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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9 * notice, this list of conditions and the following disclaimer.
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14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
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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 $
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/domain.h>
41 #include <sys/fcntl.h>
42 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */
44 #include <sys/filedesc.h>
46 #include <sys/namei.h>
48 #include <sys/protosw.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/resourcevar.h>
53 #include <sys/sysctl.h>
55 #include <sys/unpcb.h>
56 #include <sys/vnode.h>
58 #include <vm/vm_zone.h>
60 static struct vm_zone *unp_zone;
61 static unp_gen_t unp_gencnt;
62 static u_int unp_count;
64 static struct unp_head unp_shead, unp_dhead;
67 * Unix communications domain.
71 * rethink name space problems
72 * need a proper out-of-band
75 static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL };
76 static ino_t unp_ino; /* prototype for fake inode numbers */
78 static int unp_attach __P((struct socket *));
79 static void unp_detach __P((struct unpcb *));
80 static int unp_bind __P((struct unpcb *,struct sockaddr *, struct proc *));
81 static int unp_connect __P((struct socket *,struct sockaddr *,
83 static void unp_disconnect __P((struct unpcb *));
84 static void unp_shutdown __P((struct unpcb *));
85 static void unp_drop __P((struct unpcb *, int));
86 static void unp_gc __P((void));
87 static void unp_scan __P((struct mbuf *, void (*)(struct file *)));
88 static void unp_mark __P((struct file *));
89 static void unp_discard __P((struct file *));
90 static int unp_internalize __P((struct mbuf *, struct proc *));
91 static int unp_listen __P((struct unpcb *, struct proc *));
94 uipc_abort(struct socket *so)
96 struct unpcb *unp = sotounpcb(so);
100 unp_drop(unp, ECONNABORTED);
107 uipc_accept(struct socket *so, struct sockaddr **nam)
109 struct unpcb *unp = sotounpcb(so);
115 * Pass back name of connected socket,
116 * if it was bound and we are still connected
117 * (our peer may have closed already!).
119 if (unp->unp_conn && unp->unp_conn->unp_addr) {
120 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr,
123 *nam = dup_sockaddr((struct sockaddr *)&sun_noname, 1);
129 uipc_attach(struct socket *so, int proto, struct proc *p)
131 struct unpcb *unp = sotounpcb(so);
135 return unp_attach(so);
139 uipc_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
141 struct unpcb *unp = sotounpcb(so);
146 return unp_bind(unp, nam, p);
150 uipc_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
152 struct unpcb *unp = sotounpcb(so);
156 return unp_connect(so, nam, curproc);
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 proc *p)
198 struct unpcb *unp = sotounpcb(so);
200 if (unp == 0 || unp->unp_vnode == 0)
202 return unp_listen(unp, p);
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,
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, 1);
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 proc *p)
271 struct unpcb *unp = sotounpcb(so);
279 if (flags & PRUS_OOB) {
284 if (control && (error = unp_internalize(control, p)))
287 switch (so->so_type) {
290 struct sockaddr *from;
297 error = unp_connect(so, nam, p);
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, p);
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, 1);
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, "");
514 register struct unpcb *unp;
517 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
518 switch (so->so_type) {
521 error = soreserve(so, unpst_sendspace, unpst_recvspace);
525 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 = curproc->p_fd->fd_rdir;
543 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead
544 : &unp_shead, unp, unp_link);
545 so->so_pcb = (caddr_t)unp;
551 register struct unpcb *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(unp, nam, p)
586 struct sockaddr *nam;
589 struct sockaddr_un *soun = (struct sockaddr_un *)nam;
590 register struct vnode *vp;
594 char buf[SOCK_MAXADDRLEN];
596 if (unp->unp_vnode != NULL)
598 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
601 strncpy(buf, soun->sun_path, namelen);
602 buf[namelen] = 0; /* null-terminate the string */
603 NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT, UIO_SYSSPACE,
605 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
611 NDFREE(&nd, NDF_ONLY_PNBUF);
620 vattr.va_type = VSOCK;
621 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask);
622 VOP_LEASE(nd.ni_dvp, p, p->p_ucred, LEASE_WRITE);
623 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
624 NDFREE(&nd, NDF_ONLY_PNBUF);
629 vp->v_socket = unp->unp_socket;
631 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam, 1);
632 VOP_UNLOCK(vp, 0, p);
637 unp_connect(so, nam, p)
639 struct sockaddr *nam;
642 register struct sockaddr_un *soun = (struct sockaddr_un *)nam;
643 register struct vnode *vp;
644 register struct socket *so2, *so3;
645 struct unpcb *unp, *unp2, *unp3;
648 char buf[SOCK_MAXADDRLEN];
650 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
653 strncpy(buf, soun->sun_path, len);
656 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, p);
661 NDFREE(&nd, NDF_ONLY_PNBUF);
662 if (vp->v_type != VSOCK) {
666 error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p);
671 error = ECONNREFUSED;
674 if (so->so_type != so2->so_type) {
678 if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
679 if ((so2->so_options & SO_ACCEPTCONN) == 0 ||
680 (so3 = sonewconn3(so2, 0, p)) == 0) {
681 error = ECONNREFUSED;
685 unp2 = sotounpcb(so2);
686 unp3 = sotounpcb(so3);
688 unp3->unp_addr = (struct sockaddr_un *)
689 dup_sockaddr((struct sockaddr *)
693 * unp_peercred management:
695 * The connecter's (client's) credentials are copied
696 * from its process structure at the time of connect()
699 cru2x(p->p_ucred, &unp3->unp_peercred);
700 unp3->unp_flags |= UNP_HAVEPC;
702 * The receiver's (server's) credentials are copied
703 * from the unp_peercred member of socket on which the
704 * former called listen(); unp_listen() cached that
705 * process's credentials at that time so we can use
708 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
709 ("unp_connect: listener without cached peercred"));
710 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
711 sizeof(unp->unp_peercred));
712 unp->unp_flags |= UNP_HAVEPC;
716 error = unp_connect2(so, so2);
723 unp_connect2(so, so2)
724 register struct socket *so;
725 register struct socket *so2;
727 register struct unpcb *unp = sotounpcb(so);
728 register struct unpcb *unp2;
730 if (so2->so_type != so->so_type)
732 unp2 = sotounpcb(so2);
733 unp->unp_conn = unp2;
734 switch (so->so_type) {
737 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
742 unp2->unp_conn = unp;
748 panic("unp_connect2");
757 register struct unpcb *unp2 = unp->unp_conn;
762 switch (unp->unp_socket->so_type) {
765 LIST_REMOVE(unp, unp_reflink);
766 unp->unp_socket->so_state &= ~SS_ISCONNECTED;
770 soisdisconnected(unp->unp_socket);
772 soisdisconnected(unp2->unp_socket);
788 prison_unpcb(struct proc *p, struct unpcb *unp)
792 if (p->p_fd->fd_rdir == unp->unp_rvnode)
798 unp_pcblist(SYSCTL_HANDLER_ARGS)
801 struct unpcb *unp, **unp_list;
804 struct unp_head *head;
806 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
809 * The process of preparing the PCB list is too time-consuming and
810 * resource-intensive to repeat twice on every request.
812 if (req->oldptr == 0) {
814 req->oldidx = 2 * (sizeof xug)
815 + (n + n/8) * sizeof(struct xunpcb);
819 if (req->newptr != 0)
823 * OK, now we're committed to doing something.
828 xug.xug_len = sizeof xug;
830 xug.xug_gen = gencnt;
831 xug.xug_sogen = so_gencnt;
832 error = SYSCTL_OUT(req, &xug, sizeof xug);
836 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
840 for (unp = LIST_FIRST(head), i = 0; unp && i < n;
841 unp = LIST_NEXT(unp, unp_link)) {
842 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->p, unp))
845 n = i; /* in case we lost some during malloc */
848 for (i = 0; i < n; i++) {
850 if (unp->unp_gencnt <= gencnt) {
852 xu.xu_len = sizeof xu;
855 * XXX - need more locking here to protect against
856 * connect/disconnect races for SMP.
859 bcopy(unp->unp_addr, &xu.xu_addr,
860 unp->unp_addr->sun_len);
861 if (unp->unp_conn && unp->unp_conn->unp_addr)
862 bcopy(unp->unp_conn->unp_addr,
864 unp->unp_conn->unp_addr->sun_len);
865 bcopy(unp, &xu.xu_unp, sizeof *unp);
866 sotoxsocket(unp->unp_socket, &xu.xu_socket);
867 error = SYSCTL_OUT(req, &xu, sizeof xu);
872 * Give the user an updated idea of our state.
873 * If the generation differs from what we told
874 * her before, she knows that something happened
875 * while we were processing this request, and it
876 * might be necessary to retry.
878 xug.xug_gen = unp_gencnt;
879 xug.xug_sogen = so_gencnt;
880 xug.xug_count = unp_count;
881 error = SYSCTL_OUT(req, &xug, sizeof xug);
883 free(unp_list, M_TEMP);
887 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
888 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
889 "List of active local datagram sockets");
890 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
891 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
892 "List of active local stream sockets");
900 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn &&
901 (so = unp->unp_conn->unp_socket))
910 struct socket *so = unp->unp_socket;
912 so->so_error = errno;
925 unp_externalize(rights)
928 struct proc *p = curproc; /* XXX */
930 register struct cmsghdr *cm = mtod(rights, struct cmsghdr *);
932 register struct file **rp;
933 register struct file *fp;
934 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm))
935 / sizeof (struct file *);
939 * if the new FD's will not fit, then we free them all
941 if (!fdavail(p, newfds)) {
942 rp = (struct file **)CMSG_DATA(cm);
943 for (i = 0; i < newfds; i++) {
946 * zero the pointer before calling unp_discard,
947 * since it may end up in unp_gc()..
955 * now change each pointer to an fd in the global table to
956 * an integer that is the index to the local fd table entry
957 * that we set up to point to the global one we are transferring.
958 * If sizeof (struct file *) is bigger than or equal to sizeof int,
959 * then do it in forward order. In that case, an integer will
960 * always come in the same place or before its corresponding
961 * struct file pointer.
962 * If sizeof (struct file *) is smaller than sizeof int, then
963 * do it in reverse order.
965 if (sizeof (struct file *) >= sizeof (int)) {
966 fdp = (int *)(cm + 1);
967 rp = (struct file **)CMSG_DATA(cm);
968 for (i = 0; i < newfds; i++) {
969 if (fdalloc(p, 0, &f))
970 panic("unp_externalize");
972 p->p_fd->fd_ofiles[f] = fp;
978 fdp = (int *)(cm + 1) + newfds - 1;
979 rp = (struct file **)CMSG_DATA(cm) + newfds - 1;
980 for (i = 0; i < newfds; i++) {
981 if (fdalloc(p, 0, &f))
982 panic("unp_externalize");
984 p->p_fd->fd_ofiles[f] = fp;
992 * Adjust length, in case sizeof(struct file *) and sizeof(int)
995 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int));
996 rights->m_len = cm->cmsg_len;
1003 unp_zone = zinit("unpcb", sizeof(struct unpcb), nmbclusters, 0, 0);
1006 LIST_INIT(&unp_dhead);
1007 LIST_INIT(&unp_shead);
1011 #define MIN(a,b) (((a)<(b))?(a):(b))
1015 unp_internalize(control, p)
1016 struct mbuf *control;
1019 struct filedesc *fdescp = p->p_fd;
1020 register struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1021 register struct file **rp;
1022 register struct file *fp;
1023 register int i, fd, *fdp;
1024 register struct cmsgcred *cmcred;
1028 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) ||
1029 cm->cmsg_level != SOL_SOCKET || cm->cmsg_len != control->m_len)
1033 * Fill in credential information.
1035 if (cm->cmsg_type == SCM_CREDS) {
1036 cmcred = (struct cmsgcred *)(cm + 1);
1037 cmcred->cmcred_pid = p->p_pid;
1038 cmcred->cmcred_uid = p->p_cred->p_ruid;
1039 cmcred->cmcred_gid = p->p_cred->p_rgid;
1040 cmcred->cmcred_euid = p->p_ucred->cr_uid;
1041 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups,
1043 for (i = 0; i < cmcred->cmcred_ngroups; i++)
1044 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i];
1048 oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int);
1050 * check that all the FDs passed in refer to legal OPEN files
1051 * If not, reject the entire operation.
1053 fdp = (int *)(cm + 1);
1054 for (i = 0; i < oldfds; i++) {
1056 if ((unsigned)fd >= fdescp->fd_nfiles ||
1057 fdescp->fd_ofiles[fd] == NULL)
1059 if (fdescp->fd_ofiles[fd]->f_type == DTYPE_KQUEUE)
1060 return (EOPNOTSUPP);
1063 * Now replace the integer FDs with pointers to
1064 * the associated global file table entry..
1065 * Allocate a bigger buffer as necessary. But if an cluster is not
1066 * enough, return E2BIG.
1068 newlen = CMSG_LEN(oldfds * sizeof(struct file *));
1069 if (newlen > MCLBYTES)
1071 if (newlen - control->m_len > M_TRAILINGSPACE(control)) {
1072 if (control->m_flags & M_EXT)
1074 MCLGET(control, M_WAIT);
1075 if ((control->m_flags & M_EXT) == 0)
1078 /* copy the data to the cluster */
1079 memcpy(mtod(control, char *), cm, cm->cmsg_len);
1080 cm = mtod(control, struct cmsghdr *);
1084 * Adjust length, in case sizeof(struct file *) and sizeof(int)
1087 control->m_len = cm->cmsg_len = newlen;
1090 * Transform the file descriptors into struct file pointers.
1091 * If sizeof (struct file *) is bigger than or equal to sizeof int,
1092 * then do it in reverse order so that the int won't get until
1094 * If sizeof (struct file *) is smaller than sizeof int, then
1095 * do it in forward order.
1097 if (sizeof (struct file *) >= sizeof (int)) {
1098 fdp = (int *)(cm + 1) + oldfds - 1;
1099 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1;
1100 for (i = 0; i < oldfds; i++) {
1101 fp = fdescp->fd_ofiles[*fdp--];
1108 fdp = (int *)(cm + 1);
1109 rp = (struct file **)CMSG_DATA(cm);
1110 for (i = 0; i < oldfds; i++) {
1111 fp = fdescp->fd_ofiles[*fdp++];
1121 static int unp_defer, unp_gcing;
1126 register struct file *fp, *nextfp;
1127 register struct socket *so;
1128 struct file **extra_ref, **fpp;
1136 * before going through all this, set all FDs to
1137 * be NOT defered and NOT externally accessible
1139 LIST_FOREACH(fp, &filehead, f_list)
1140 fp->f_flag &= ~(FMARK|FDEFER);
1142 LIST_FOREACH(fp, &filehead, f_list) {
1144 * If the file is not open, skip it
1146 if (fp->f_count == 0)
1149 * If we already marked it as 'defer' in a
1150 * previous pass, then try process it this time
1153 if (fp->f_flag & FDEFER) {
1154 fp->f_flag &= ~FDEFER;
1158 * if it's not defered, then check if it's
1159 * already marked.. if so skip it
1161 if (fp->f_flag & FMARK)
1164 * If all references are from messages
1165 * in transit, then skip it. it's not
1166 * externally accessible.
1168 if (fp->f_count == fp->f_msgcount)
1171 * If it got this far then it must be
1172 * externally accessible.
1174 fp->f_flag |= FMARK;
1177 * either it was defered, or it is externally
1178 * accessible and not already marked so.
1179 * Now check if it is possibly one of OUR sockets.
1181 if (fp->f_type != DTYPE_SOCKET ||
1182 (so = (struct socket *)fp->f_data) == 0)
1184 if (so->so_proto->pr_domain != &localdomain ||
1185 (so->so_proto->pr_flags&PR_RIGHTS) == 0)
1188 if (so->so_rcv.sb_flags & SB_LOCK) {
1190 * This is problematical; it's not clear
1191 * we need to wait for the sockbuf to be
1192 * unlocked (on a uniprocessor, at least),
1193 * and it's also not clear what to do
1194 * if sbwait returns an error due to receipt
1195 * of a signal. If sbwait does return
1196 * an error, we'll go into an infinite
1197 * loop. Delete all of this for now.
1199 (void) sbwait(&so->so_rcv);
1204 * So, Ok, it's one of our sockets and it IS externally
1205 * accessible (or was defered). Now we look
1206 * to see if we hold any file descriptors in its
1207 * message buffers. Follow those links and mark them
1208 * as accessible too.
1210 unp_scan(so->so_rcv.sb_mb, unp_mark);
1212 } while (unp_defer);
1214 * We grab an extra reference to each of the file table entries
1215 * that are not otherwise accessible and then free the rights
1216 * that are stored in messages on them.
1218 * The bug in the orginal code is a little tricky, so I'll describe
1219 * what's wrong with it here.
1221 * It is incorrect to simply unp_discard each entry for f_msgcount
1222 * times -- consider the case of sockets A and B that contain
1223 * references to each other. On a last close of some other socket,
1224 * we trigger a gc since the number of outstanding rights (unp_rights)
1225 * is non-zero. If during the sweep phase the gc code un_discards,
1226 * we end up doing a (full) closef on the descriptor. A closef on A
1227 * results in the following chain. Closef calls soo_close, which
1228 * calls soclose. Soclose calls first (through the switch
1229 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply
1230 * returns because the previous instance had set unp_gcing, and
1231 * we return all the way back to soclose, which marks the socket
1232 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush
1233 * to free up the rights that are queued in messages on the socket A,
1234 * i.e., the reference on B. The sorflush calls via the dom_dispose
1235 * switch unp_dispose, which unp_scans with unp_discard. This second
1236 * instance of unp_discard just calls closef on B.
1238 * Well, a similar chain occurs on B, resulting in a sorflush on B,
1239 * which results in another closef on A. Unfortunately, A is already
1240 * being closed, and the descriptor has already been marked with
1241 * SS_NOFDREF, and soclose panics at this point.
1243 * Here, we first take an extra reference to each inaccessible
1244 * descriptor. Then, we call sorflush ourself, since we know
1245 * it is a Unix domain socket anyhow. After we destroy all the
1246 * rights carried in messages, we do a last closef to get rid
1247 * of our extra reference. This is the last close, and the
1248 * unp_detach etc will shut down the socket.
1250 * 91/09/19, bsy@cs.cmu.edu
1252 extra_ref = malloc(nfiles * sizeof(struct file *), M_FILE, M_WAITOK);
1253 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; fp != 0;
1255 nextfp = LIST_NEXT(fp, f_list);
1257 * If it's not open, skip it
1259 if (fp->f_count == 0)
1262 * If all refs are from msgs, and it's not marked accessible
1263 * then it must be referenced from some unreachable cycle
1264 * of (shut-down) FDs, so include it in our
1265 * list of FDs to remove
1267 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) {
1274 * for each FD on our hit list, do the following two things
1276 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) {
1277 struct file *tfp = *fpp;
1278 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL)
1279 sorflush((struct socket *)(tfp->f_data));
1281 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp)
1282 closef(*fpp, (struct proc *) NULL);
1283 free((caddr_t)extra_ref, M_FILE);
1293 unp_scan(m, unp_discard);
1302 cru2x(p->p_ucred, &unp->unp_peercred);
1303 unp->unp_flags |= UNP_HAVEPCCACHED;
1309 register struct mbuf *m0;
1310 void (*op) __P((struct file *));
1312 register struct mbuf *m;
1313 register struct file **rp;
1314 register struct cmsghdr *cm;
1319 for (m = m0; m; m = m->m_next)
1320 if (m->m_type == MT_CONTROL &&
1321 m->m_len >= sizeof(*cm)) {
1322 cm = mtod(m, struct cmsghdr *);
1323 if (cm->cmsg_level != SOL_SOCKET ||
1324 cm->cmsg_type != SCM_RIGHTS)
1326 qfds = (cm->cmsg_len -
1327 (CMSG_DATA(cm) - (u_char *)cm))
1328 / sizeof (struct file *);
1329 rp = (struct file **)CMSG_DATA(cm);
1330 for (i = 0; i < qfds; i++)
1332 break; /* XXX, but saves time */
1343 if (fp->f_flag & FMARK)
1346 fp->f_flag |= (FMARK|FDEFER);
1356 (void) closef(fp, (struct proc *)NULL);