1 /*-
2  * Copyright (c) 1992, 1993, 1995
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_vfsops.c	8.11 (Berkeley) 5/14/95
33  *
34  * $FreeBSD: stable/9/sys/fs/portalfs/portal_vfsops.c 230725 2012-01-29 08:03:45Z mckusick $
35  */
36 
37 /*
38  * Portal Filesystem
39  */
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/capability.h>
44 #include <sys/domain.h>
45 #include <sys/filedesc.h>
46 #include <sys/kernel.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/malloc.h>
50 #include <sys/file.h>		/* Must come after sys/malloc.h */
51 #include <sys/mount.h>
52 #include <sys/proc.h>
53 #include <sys/protosw.h>
54 #include <sys/socket.h>
55 #include <sys/socketvar.h>
56 #include <sys/vnode.h>
57 
58 #include <fs/portalfs/portal.h>
59 
60 static MALLOC_DEFINE(M_PORTALFSMNT, "portal_mount", "PORTAL mount structure");
61 
62 static vfs_unmount_t	portal_unmount;
63 static vfs_root_t	portal_root;
64 static vfs_statfs_t	portal_statfs;
65 
66 static const char *portal_opts[] = {
67 	"socket", "config",
68 	NULL
69 };
70 
71 static int
portal_cmount(struct mntarg * ma,void * data,uint64_t flags)72 portal_cmount(struct mntarg *ma, void *data, uint64_t flags)
73 {
74 	struct portal_args args;
75 	int error;
76 
77 	if (data == NULL)
78 		return (EINVAL);
79 	error = copyin(data, &args, sizeof args);
80 	if (error)
81 		return (error);
82 
83 	ma = mount_argf(ma, "socket", "%d", args.pa_socket);
84 	ma = mount_argsu(ma, "config", args.pa_config, MAXPATHLEN);
85 	error = kernel_mount(ma, flags);
86 
87 	return (error);
88 }
89 
90 /*
91  * Mount the per-process file descriptors (/dev/fd)
92  */
93 static int
portal_mount(struct mount * mp)94 portal_mount(struct mount *mp)
95 {
96 	struct file *fp;
97 	struct portalmount *fmp;
98 	struct socket *so;
99 	struct vnode *rvp;
100 	struct thread *td;
101 	struct portalnode *pn;
102 	int error, v;
103 	char *p;
104 
105 	td = curthread;
106 	if (vfs_filteropt(mp->mnt_optnew, portal_opts))
107 		return (EINVAL);
108 
109 	error = vfs_scanopt(mp->mnt_optnew, "socket", "%d", &v);
110 	if (error != 1)
111 		return (EINVAL);
112 	error = vfs_getopt(mp->mnt_optnew, "config", (void **)&p, NULL);
113 	if (error)
114 		return (error);
115 
116 	/*
117 	 * Capsicum is not incompatible with portalfs, but we don't really
118 	 * know what rights are required. In the spirit of "better safe than
119 	 * sorry", pretend that all rights are required for now.
120 	 */
121 	if ((error = fget(td, v, CAP_MASK_VALID, &fp)) != 0)
122 		return (error);
123         if (fp->f_type != DTYPE_SOCKET) {
124 		fdrop(fp, td);
125                 return(ENOTSOCK);
126 	}
127 	so = fp->f_data;	/* XXX race against userland */
128 	if (so->so_proto->pr_domain->dom_family != AF_UNIX) {
129 		fdrop(fp, td);
130 		return (ESOCKTNOSUPPORT);
131 	}
132 
133 	pn = malloc(sizeof(struct portalnode),
134 		M_TEMP, M_WAITOK);
135 
136 	fmp = malloc(sizeof(struct portalmount),
137 		M_PORTALFSMNT, M_WAITOK);	/* XXX */
138 
139 	error = getnewvnode("portal", mp, &portal_vnodeops, &rvp); /* XXX */
140 	if (error) {
141 		free(fmp, M_PORTALFSMNT);
142 		free(pn, M_TEMP);
143 		fdrop(fp, td);
144 		return (error);
145 	}
146 
147 	error = insmntque(rvp, mp);	/* XXX: Too early for mpsafe fs */
148 	if (error != 0) {
149 		free(fmp, M_PORTALFSMNT);
150 		free(pn, M_TEMP);
151 		fdrop(fp, td);
152 		return (error);
153 	}
154 	rvp->v_data = pn;
155 	rvp->v_type = VDIR;
156 	rvp->v_vflag |= VV_ROOT;
157 	VTOPORTAL(rvp)->pt_arg = 0;
158 	VTOPORTAL(rvp)->pt_size = 0;
159 	VTOPORTAL(rvp)->pt_fileid = PORTAL_ROOTFILEID;
160 	fmp->pm_root = rvp;
161 	fhold(fp);
162 	fmp->pm_server = fp;
163 
164 	MNT_ILOCK(mp);
165 	mp->mnt_flag |= MNT_LOCAL;
166 	MNT_IUNLOCK(mp);
167 	mp->mnt_data =  fmp;
168 	vfs_getnewfsid(mp);
169 
170 	vfs_mountedfrom(mp, p);
171 	fdrop(fp, td);
172 	return (0);
173 }
174 
175 static int
portal_unmount(mp,mntflags)176 portal_unmount(mp, mntflags)
177 	struct mount *mp;
178 	int mntflags;
179 {
180 	int error, flags = 0;
181 
182 
183 	if (mntflags & MNT_FORCE)
184 		flags |= FORCECLOSE;
185 
186 	/*
187 	 * Clear out buffer cache.  I don't think we
188 	 * ever get anything cached at this level at the
189 	 * moment, but who knows...
190 	 */
191 #ifdef notyet
192 	mntflushbuf(mp, 0);
193 	if (mntinvalbuf(mp, 1))
194 		return (EBUSY);
195 #endif
196 	/* There is 1 extra root vnode reference (pm_root). */
197 	error = vflush(mp, 1, flags, curthread);
198 	if (error)
199 		return (error);
200 
201 	/*
202 	 * Shutdown the socket.  This will cause the select in the
203 	 * daemon to wake up, and then the accept will get ECONNABORTED
204 	 * which it interprets as a request to go and bury itself.
205 	 */
206 	soshutdown(VFSTOPORTAL(mp)->pm_server->f_data, 2);
207 	/*
208 	 * Discard reference to underlying file.  Must call closef because
209 	 * this may be the last reference.
210 	 */
211 	closef(VFSTOPORTAL(mp)->pm_server, (struct thread *) 0);
212 	/*
213 	 * Finally, throw away the portalmount structure
214 	 */
215 	free(mp->mnt_data, M_PORTALFSMNT);	/* XXX */
216 	mp->mnt_data = 0;
217 	return (0);
218 }
219 
220 static int
portal_root(mp,flags,vpp)221 portal_root(mp, flags, vpp)
222 	struct mount *mp;
223 	int flags;
224 	struct vnode **vpp;
225 {
226 	struct vnode *vp;
227 
228 	/*
229 	 * Return locked reference to root.
230 	 */
231 	vp = VFSTOPORTAL(mp)->pm_root;
232 	VREF(vp);
233 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
234 	*vpp = vp;
235 	return (0);
236 }
237 
238 static int
portal_statfs(mp,sbp)239 portal_statfs(mp, sbp)
240 	struct mount *mp;
241 	struct statfs *sbp;
242 {
243 
244 	sbp->f_flags = 0;
245 	sbp->f_bsize = DEV_BSIZE;
246 	sbp->f_iosize = DEV_BSIZE;
247 	sbp->f_blocks = 2;		/* 1K to keep df happy */
248 	sbp->f_bfree = 0;
249 	sbp->f_bavail = 0;
250 	sbp->f_files = 1;		/* Allow for "." */
251 	sbp->f_ffree = 0;		/* See comments above */
252 	return (0);
253 }
254 
255 static struct vfsops portal_vfsops = {
256 	.vfs_cmount =		portal_cmount,
257 	.vfs_mount =		portal_mount,
258 	.vfs_root =		portal_root,
259 	.vfs_statfs =		portal_statfs,
260 	.vfs_unmount =		portal_unmount,
261 };
262 
263 VFS_SET(portal_vfsops, portalfs, VFCF_SYNTHETIC);
264