1 /*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software donated to Berkeley by
6 * Jan-Simon Pendry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)portal_vnops.c 8.14 (Berkeley) 5/21/95
33 *
34 * $FreeBSD: releng/8.0/sys/fs/portalfs/portal_vnops.c 194498 2009-06-19 17:10:35Z brooks $
35 */
36
37 /*
38 * Portal Filesystem
39 */
40
41 #include <sys/param.h>
42 #include <sys/fcntl.h>
43 #include <sys/file.h>
44 #include <sys/kernel.h>
45 #include <sys/lock.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/mount.h>
49 #include <sys/mutex.h>
50 #include <sys/namei.h>
51 #include <sys/proc.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/stat.h>
55 #include <sys/syscallsubr.h>
56 #include <sys/systm.h>
57 #include <sys/un.h>
58 #include <sys/unpcb.h>
59 #include <sys/vnode.h>
60
61 #include <fs/portalfs/portal.h>
62
63 static int portal_fileid = PORTAL_ROOTFILEID+1;
64
65 static void portal_closefd(struct thread *td, int fd);
66 static int portal_connect(struct socket *so, struct socket *so2);
67 static vop_getattr_t portal_getattr;
68 static vop_lookup_t portal_lookup;
69 static vop_open_t portal_open;
70 static vop_readdir_t portal_readdir;
71 static vop_reclaim_t portal_reclaim;
72 static vop_setattr_t portal_setattr;
73
74 static void
75 portal_closefd(td, fd)
76 struct thread *td;
77 int fd;
78 {
79 int error;
80
81 error = kern_close(td, fd);
82 /*
83 * We should never get an error, and there isn't anything
84 * we could do if we got one, so just print a message.
85 */
86 if (error)
87 printf("portal_closefd: error = %d\n", error);
88 }
89
90 /*
91 * vp is the current namei directory
92 * cnp is the name to locate in that directory...
93 */
94 static int
95 portal_lookup(ap)
96 struct vop_lookup_args /* {
97 struct vnode * a_dvp;
98 struct vnode ** a_vpp;
99 struct componentname * a_cnp;
100 } */ *ap;
101 {
102 struct componentname *cnp = ap->a_cnp;
103 struct vnode **vpp = ap->a_vpp;
104 struct vnode *dvp = ap->a_dvp;
105 char *pname = cnp->cn_nameptr;
106 struct portalnode *pt;
107 int error;
108 struct vnode *fvp = 0;
109 char *path;
110 int size;
111
112 *vpp = NULLVP;
113
114 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)
115 return (EROFS);
116
117 if (cnp->cn_namelen == 1 && *pname == '.') {
118 *vpp = dvp;
119 VREF(dvp);
120 return (0);
121 }
122 KASSERT((cnp->cn_flags & ISDOTDOT) == 0,
123 ("portal_lookup: Can not handle dotdot lookups."));
124
125 /*
126 * Do the MALLOC before the getnewvnode since doing so afterward
127 * might cause a bogus v_data pointer to get dereferenced
128 * elsewhere if MALLOC should block.
129 */
130 pt = malloc(sizeof(struct portalnode),
131 M_TEMP, M_WAITOK);
132
133 error = getnewvnode("portal", dvp->v_mount, &portal_vnodeops, &fvp);
134 if (error) {
135 free(pt, M_TEMP);
136 goto bad;
137 }
138 fvp->v_type = VREG;
139 fvp->v_data = pt;
140 /*
141 * Save all of the remaining pathname and
142 * advance the namei next pointer to the end
143 * of the string.
144 */
145 for (size = 0, path = pname; *path; path++)
146 size++;
147 cnp->cn_consume = size - cnp->cn_namelen;
148
149 pt->pt_arg = malloc(size+1, M_TEMP, M_WAITOK);
150 pt->pt_size = size+1;
151 bcopy(pname, pt->pt_arg, pt->pt_size);
152 pt->pt_fileid = portal_fileid++;
153
154 *vpp = fvp;
155 vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY);
156 error = insmntque(fvp, dvp->v_mount);
157 if (error != 0) {
158 *vpp = NULLVP;
159 return (error);
160 }
161 return (0);
162
163 bad:;
164 if (fvp)
165 vrele(fvp);
166 return (error);
167 }
168
169 static int
170 portal_connect(so, so2)
171 struct socket *so;
172 struct socket *so2;
173 {
174 /* from unp_connect, bypassing the namei stuff... */
175 struct socket *so3;
176 struct unpcb *unp2;
177 struct unpcb *unp3;
178
179 if (so2 == 0)
180 return (ECONNREFUSED);
181
182 if (so->so_type != so2->so_type)
183 return (EPROTOTYPE);
184
185 if ((so2->so_options & SO_ACCEPTCONN) == 0)
186 return (ECONNREFUSED);
187
188 if ((so3 = sonewconn(so2, 0)) == 0)
189 return (ECONNREFUSED);
190
191 unp2 = sotounpcb(so2);
192 unp3 = sotounpcb(so3);
193 if (unp2->unp_addr)
194 unp3->unp_addr = (struct sockaddr_un *)
195 sodupsockaddr((struct sockaddr *)unp2->unp_addr,
196 M_NOWAIT);
197 so2 = so3;
198
199 return (soconnect2(so, so2));
200 }
201
202 static int
203 portal_open(ap)
204 struct vop_open_args /* {
205 struct vnode *a_vp;
206 int a_mode;
207 struct ucred *a_cred;
208 struct thread *a_td;
209 } */ *ap;
210 {
211 struct socket *so = 0;
212 struct portalnode *pt;
213 struct thread *td = ap->a_td;
214 struct vnode *vp = ap->a_vp;
215 struct uio auio;
216 struct iovec aiov[2];
217 int res;
218 struct mbuf *cm = 0;
219 struct cmsghdr *cmsg;
220 int newfds;
221 int *ip;
222 int fd;
223 int error;
224 int len;
225 struct portalmount *fmp;
226 struct file *fp;
227 struct portal_cred pcred;
228
229 /*
230 * Nothing to do when opening the root node.
231 */
232 if (vp->v_vflag & VV_ROOT)
233 return (0);
234
235 /*
236 * Can't be opened unless the caller is set up
237 * to deal with the side effects. Check for this
238 * by testing whether td_dupfd has been set.
239 */
240 if (td->td_dupfd >= 0)
241 return (ENODEV);
242
243 pt = VTOPORTAL(vp);
244 fmp = VFSTOPORTAL(vp->v_mount);
245
246 /*
247 * Create a new socket.
248 */
249 error = socreate(AF_UNIX, &so, SOCK_STREAM, 0, ap->a_td->td_ucred,
250 ap->a_td);
251 if (error)
252 goto bad;
253
254 /*
255 * Reserve some buffer space
256 */
257 res = pt->pt_size + sizeof(pcred) + 512; /* XXX */
258 error = soreserve(so, res, res);
259 if (error)
260 goto bad;
261
262 /*
263 * Kick off connection
264 */
265 error = portal_connect(so, fmp->pm_server->f_data);
266 if (error)
267 goto bad;
268
269 /*
270 * Wait for connection to complete
271 */
272 /*
273 * XXX: Since the mount point is holding a reference on the
274 * underlying server socket, it is not easy to find out whether
275 * the server process is still running. To handle this problem
276 * we loop waiting for the new socket to be connected (something
277 * which will only happen if the server is still running) or for
278 * the reference count on the server socket to drop to 1, which
279 * will happen if the server dies. Sleep for 5 second intervals
280 * and keep polling the reference count. XXX.
281 */
282 SOCK_LOCK(so);
283 while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
284 if (fmp->pm_server->f_count == 1) {
285 SOCK_UNLOCK(so);
286 error = ECONNREFUSED;
287 goto bad;
288 }
289 (void) msleep((caddr_t) &so->so_timeo, SOCK_MTX(so), PSOCK,
290 "portalcon", 5 * hz);
291 }
292 SOCK_UNLOCK(so);
293
294 if (so->so_error) {
295 error = so->so_error;
296 goto bad;
297 }
298
299 /*
300 * Set miscellaneous flags
301 */
302 SOCKBUF_LOCK(&so->so_rcv);
303 so->so_rcv.sb_timeo = 0;
304 so->so_rcv.sb_flags |= SB_NOINTR;
305 SOCKBUF_UNLOCK(&so->so_rcv);
306 SOCKBUF_LOCK(&so->so_snd);
307 so->so_snd.sb_timeo = 0;
308 so->so_snd.sb_flags |= SB_NOINTR;
309 SOCKBUF_UNLOCK(&so->so_snd);
310
311
312 pcred.pcr_flag = ap->a_mode;
313 pcred.pcr_uid = ap->a_cred->cr_uid;
314 pcred.pcr_ngroups = MIN(ap->a_cred->cr_ngroups, XU_NGROUPS);
315 bcopy(ap->a_cred->cr_groups, pcred.pcr_groups,
316 pcred.pcr_ngroups * sizeof(gid_t));
317 aiov[0].iov_base = (caddr_t) &pcred;
318 aiov[0].iov_len = sizeof(pcred);
319 aiov[1].iov_base = pt->pt_arg;
320 aiov[1].iov_len = pt->pt_size;
321 auio.uio_iov = aiov;
322 auio.uio_iovcnt = 2;
323 auio.uio_rw = UIO_WRITE;
324 auio.uio_segflg = UIO_SYSSPACE;
325 auio.uio_td = td;
326 auio.uio_offset = 0;
327 auio.uio_resid = aiov[0].iov_len + aiov[1].iov_len;
328
329 error = sosend(so, (struct sockaddr *) 0, &auio,
330 (struct mbuf *) 0, (struct mbuf *) 0, 0 , td);
331 if (error)
332 goto bad;
333
334 len = auio.uio_resid = sizeof(int);
335 do {
336 struct mbuf *m = 0;
337 int flags = MSG_WAITALL;
338 error = soreceive(so, (struct sockaddr **) 0, &auio,
339 &m, &cm, &flags);
340 if (error)
341 goto bad;
342
343 /*
344 * Grab an error code from the mbuf.
345 */
346 if (m) {
347 m = m_pullup(m, sizeof(int)); /* Needed? */
348 if (m) {
349 error = *(mtod(m, int *));
350 m_freem(m);
351 } else {
352 error = EINVAL;
353 }
354 } else {
355 if (cm == 0) {
356 error = ECONNRESET; /* XXX */
357 #ifdef notdef
358 break;
359 #endif
360 }
361 }
362 } while (cm == 0 && auio.uio_resid == len && !error);
363
364 if (cm == 0)
365 goto bad;
366
367 if (auio.uio_resid) {
368 error = 0;
369 #ifdef notdef
370 error = EMSGSIZE;
371 goto bad;
372 #endif
373 }
374
375 /*
376 * XXX: Break apart the control message, and retrieve the
377 * received file descriptor. Note that more than one descriptor
378 * may have been received, or that the rights chain may have more
379 * than a single mbuf in it. What to do?
380 */
381 cmsg = mtod(cm, struct cmsghdr *);
382 newfds = (cmsg->cmsg_len - sizeof(*cmsg)) / sizeof (int);
383 if (newfds == 0) {
384 error = ECONNREFUSED;
385 goto bad;
386 }
387 /*
388 * At this point the rights message consists of a control message
389 * header, followed by a data region containing a vector of
390 * integer file descriptors. The fds were allocated by the action
391 * of receiving the control message.
392 */
393 ip = (int *) (cmsg + 1);
394 fd = *ip++;
395 if (newfds > 1) {
396 /*
397 * Close extra fds.
398 */
399 int i;
400 printf("portal_open: %d extra fds\n", newfds - 1);
401 for (i = 1; i < newfds; i++) {
402 portal_closefd(td, *ip);
403 ip++;
404 }
405 }
406
407 /*
408 * Check that the mode the file is being opened for is a subset
409 * of the mode of the existing descriptor.
410 */
411 if ((error = fget(td, fd, &fp)) != 0)
412 goto bad;
413 if (((ap->a_mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
414 fdrop(fp, td);
415 portal_closefd(td, fd);
416 error = EACCES;
417 goto bad;
418 }
419 fdrop(fp, td);
420
421 /*
422 * Save the dup fd in the proc structure then return the
423 * special error code (ENXIO) which causes magic things to
424 * happen in vn_open. The whole concept is, well, hmmm.
425 */
426 td->td_dupfd = fd;
427 error = ENXIO;
428
429 bad:;
430 /*
431 * And discard the control message.
432 */
433 if (cm) {
434 m_freem(cm);
435 }
436
437 if (so) {
438 soshutdown(so, 2);
439 soclose(so);
440 }
441 return (error);
442 }
443
444 static int
445 portal_getattr(ap)
446 struct vop_getattr_args /* {
447 struct vnode *a_vp;
448 struct vattr *a_vap;
449 struct ucred *a_cred;
450 } */ *ap;
451 {
452 struct vnode *vp = ap->a_vp;
453 struct vattr *vap = ap->a_vap;
454
455 vap->va_uid = 0;
456 vap->va_gid = 0;
457 vap->va_size = DEV_BSIZE;
458 vap->va_blocksize = DEV_BSIZE;
459 nanotime(&vap->va_atime);
460 vap->va_mtime = vap->va_atime;
461 vap->va_ctime = vap->va_mtime;
462 vap->va_gen = 0;
463 vap->va_flags = 0;
464 vap->va_rdev = NODEV;
465 /* vap->va_qbytes = 0; */
466 vap->va_bytes = 0;
467 vap->va_filerev = 0;
468 /* vap->va_qsize = 0; */
469 if (vp->v_vflag & VV_ROOT) {
470 vap->va_type = VDIR;
471 vap->va_mode = S_IRUSR|S_IWUSR|S_IXUSR|
472 S_IRGRP|S_IWGRP|S_IXGRP|
473 S_IROTH|S_IWOTH|S_IXOTH;
474 vap->va_nlink = 2;
475 vap->va_fileid = 2;
476 } else {
477 vap->va_type = VREG;
478 vap->va_mode = S_IRUSR|S_IWUSR|
479 S_IRGRP|S_IWGRP|
480 S_IROTH|S_IWOTH;
481 vap->va_nlink = 1;
482 vap->va_fileid = VTOPORTAL(vp)->pt_fileid;
483 }
484 return (0);
485 }
486
487 static int
488 portal_setattr(ap)
489 struct vop_setattr_args /* {
490 struct vnode *a_vp;
491 struct vattr *a_vap;
492 struct ucred *a_cred;
493 } */ *ap;
494 {
495
496 /*
497 * Can't mess with the root vnode
498 */
499 if (ap->a_vp->v_vflag & VV_ROOT)
500 return (EACCES);
501
502 if (ap->a_vap->va_flags != VNOVAL)
503 return (EOPNOTSUPP);
504
505 return (0);
506 }
507
508 /*
509 * Fake readdir, just return empty directory.
510 * It is hard to deal with '.' and '..' so don't bother.
511 */
512 static int
513 portal_readdir(ap)
514 struct vop_readdir_args /* {
515 struct vnode *a_vp;
516 struct uio *a_uio;
517 struct ucred *a_cred;
518 int *a_eofflag;
519 u_long *a_cookies;
520 int a_ncookies;
521 } */ *ap;
522 {
523
524 /*
525 * We don't allow exporting portal mounts, and currently local
526 * requests do not need cookies.
527 */
528 if (ap->a_ncookies)
529 panic("portal_readdir: not hungry");
530
531 return (0);
532 }
533
534 static int
535 portal_reclaim(ap)
536 struct vop_reclaim_args /* {
537 struct vnode *a_vp;
538 } */ *ap;
539 {
540 struct portalnode *pt = VTOPORTAL(ap->a_vp);
541
542 if (pt->pt_arg) {
543 free((caddr_t) pt->pt_arg, M_TEMP);
544 pt->pt_arg = 0;
545 }
546 free(ap->a_vp->v_data, M_TEMP);
547 ap->a_vp->v_data = 0;
548
549 return (0);
550 }
551
552 struct vop_vector portal_vnodeops = {
553 .vop_default = &default_vnodeops,
554
555 .vop_access = VOP_NULL,
556 .vop_getattr = portal_getattr,
557 .vop_lookup = portal_lookup,
558 .vop_open = portal_open,
559 .vop_pathconf = vop_stdpathconf,
560 .vop_readdir = portal_readdir,
561 .vop_reclaim = portal_reclaim,
562 .vop_setattr = portal_setattr,
563 };
Cache object: c2cae8c2382b488b06459ef10ce65521
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