1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
26 /* All Rights Reserved */
27
28
29 #include <sys/types.h>
30 #include <sys/param.h>
31 #include <sys/cmn_err.h>
32 #include <sys/cred.h>
33 #include <sys/debug.h>
34 #include <sys/errno.h>
35 #include <sys/proc.h>
36 #include <sys/procfs.h>
37 #include <sys/stat.h>
38 #include <sys/statvfs.h>
39 #include <sys/sysmacros.h>
40 #include <sys/systm.h>
41 #include <sys/zone.h>
42 #include <sys/var.h>
43 #include <sys/vfs.h>
44 #include <sys/vfs_opreg.h>
45 #include <sys/vnode.h>
46 #include <sys/mode.h>
47 #include <sys/signal.h>
48 #include <sys/user.h>
49 #include <sys/mount.h>
50 #include <sys/bitmap.h>
51 #include <sys/kmem.h>
52 #include <sys/policy.h>
53 #include <fs/fs_subr.h>
54 #include <fs/proc/prdata.h>
55
56 /*
57 * This is the loadable module wrapper.
58 */
59 #include <sys/modctl.h>
60
61 static int prinit();
62
63 static mntopts_t proc_mntopts = {
64 NULL,
65 0
66 };
67
68 static vfsdef_t vfw = {
69 VFSDEF_VERSION,
70 "proc",
71 prinit,
72 VSW_HASPROTO|VSW_STATS|VSW_XID|VSW_ZMOUNT,
73 &proc_mntopts
74 };
75
76 /*
77 * Module linkage information for the kernel.
78 */
79 extern struct mod_ops mod_fsops;
80
81 static struct modlfs modlfs = {
82 &mod_fsops, "filesystem for proc", &vfw
83 };
84
85 static struct modlinkage modlinkage = {
86 MODREV_1, { (void *)&modlfs, NULL }
87 };
88
89 int
90 _init(void)
91 {
92 return (mod_install(&modlinkage));
93 }
94
95 int
96 _info(struct modinfo *modinfop)
97 {
98 return (mod_info(&modlinkage, modinfop));
99 }
100
101 /*
102 * N.B.
103 * No _fini routine. The module cannot be unloaded once loaded.
104 * The NO_UNLOAD_STUB in modstubs.s must change if this module
105 * is ever modified to become unloadable.
106 */
107
108 int nproc_highbit; /* highbit(v.v_nproc) */
109
110 static int procfstype;
111 static major_t procfs_major;
112 static minor_t procfs_minor;
113 static kmutex_t procfs_minor_lock;
114
115 static kmutex_t pr_mount_lock;
116
117 /*
118 * /proc VFS operations vector.
119 */
120 static int prmount(), prunmount(), prroot(), prstatvfs();
121
122 static void
123 prinitrootnode(prnode_t *pnp, vfs_t *vfsp)
124 {
125 struct vnode *vp;
126
127 bzero((caddr_t)pnp, sizeof (*pnp));
128 pnp->pr_vnode = vp = vn_alloc(KM_SLEEP);
129
130 mutex_init(&pnp->pr_mutex, NULL, MUTEX_DEFAULT, NULL);
131 vp->v_flag = VROOT|VNOCACHE|VNOMAP|VNOSWAP|VNOMOUNT;
132 VN_SET_VFS_TYPE_DEV(vp, vfsp, VDIR, 0);
133 vn_setops(vp, prvnodeops);
134 vp->v_data = (caddr_t)pnp;
135 pnp->pr_type = PR_PROCDIR;
136 pnp->pr_mode = 0555; /* read-search by everyone */
137 vn_exists(vp);
138 }
139
140 static int
141 prinit(int fstype, char *name)
142 {
143 static const fs_operation_def_t pr_vfsops_template[] = {
144 { VFSNAME_MOUNT, { .vfs_mount = prmount } },
145 { VFSNAME_UNMOUNT, { .vfs_unmount = prunmount } },
146 { VFSNAME_ROOT, { .vfs_root = prroot } },
147 { VFSNAME_STATVFS, { .vfs_statvfs = prstatvfs } },
148 { NULL, { NULL } }
149 };
150 extern const fs_operation_def_t pr_vnodeops_template[];
151 int error;
152
153 nproc_highbit = highbit(v.v_proc);
154 procfstype = fstype;
155 ASSERT(procfstype != 0);
156 /*
157 * Associate VFS ops vector with this fstype.
158 */
159 error = vfs_setfsops(fstype, pr_vfsops_template, NULL);
160 if (error != 0) {
161 cmn_err(CE_WARN, "prinit: bad vfs ops template");
162 return (error);
163 }
164
165 /*
166 * Set up vnode ops vector too.
167 */
168
169 error = vn_make_ops(name, pr_vnodeops_template, &prvnodeops);
170 if (error != 0) {
171 (void) vfs_freevfsops_by_type(fstype);
172 cmn_err(CE_WARN, "prinit: bad vnode ops template");
173 return (error);
174 }
175
176 /*
177 * Assign a unique "device" number (used by stat(2)).
178 */
179 if ((procfs_major = getudev()) == (major_t)-1) {
180 cmn_err(CE_WARN, "prinit: can't get unique device number");
181 procfs_major = 0;
182 }
183 mutex_init(&pr_mount_lock, NULL, MUTEX_DEFAULT, NULL);
184 mutex_init(&procfs_minor_lock, NULL, MUTEX_DEFAULT, NULL);
185
186 return (0);
187 }
188
189 /* ARGSUSED */
190 static int
191 prmount(struct vfs *vfsp, struct vnode *mvp,
192 struct mounta *uap, struct cred *cr)
193 {
194 prnode_t *pnp;
195 zone_t *zone = curproc->p_zone;
196
197 if (secpolicy_fs_mount(cr, mvp, vfsp) != 0)
198 return (EPERM);
199
200 if (mvp->v_type != VDIR)
201 return (ENOTDIR);
202
203 if (zone == global_zone) {
204 zone_t *mntzone;
205
206 mntzone = zone_find_by_path(refstr_value(vfsp->vfs_mntpt));
207 zone_rele(mntzone);
208 if (zone != mntzone)
209 return (EBUSY);
210 }
211 /*
212 * Having the resource be anything but "proc" doesn't make sense
213 */
214 vfs_setresource(vfsp, "proc", 0);
215
216 pnp = kmem_alloc(sizeof (*pnp), KM_SLEEP);
217 mutex_enter(&pr_mount_lock);
218
219 mutex_enter(&mvp->v_lock);
220 if ((uap->flags & MS_OVERLAY) == 0 &&
221 (mvp->v_count > 1 || (mvp->v_flag & VROOT))) {
222 mutex_exit(&mvp->v_lock);
223 mutex_exit(&pr_mount_lock);
224 kmem_free(pnp, sizeof (*pnp));
225 return (EBUSY);
226 }
227 mutex_exit(&mvp->v_lock);
228
229 prinitrootnode(pnp, vfsp);
230 vfsp->vfs_fstype = procfstype;
231 vfsp->vfs_data = (caddr_t)pnp;
232 vfsp->vfs_bsize = DEV_BSIZE;
233 /*
234 * find an available minor device number for this mount
235 */
236 mutex_enter(&procfs_minor_lock);
237 do {
238 vfsp->vfs_dev = makedevice(procfs_major, procfs_minor);
239 procfs_minor = (procfs_minor + 1) & L_MAXMIN32;
240 } while (vfs_devismounted(vfsp->vfs_dev));
241 mutex_exit(&procfs_minor_lock);
242 vfs_make_fsid(&vfsp->vfs_fsid, vfsp->vfs_dev, procfstype);
243
244 mutex_exit(&pr_mount_lock);
245 return (0);
246 }
247
248 /* ARGSUSED */
249 static int
250 prunmount(struct vfs *vfsp, int flag, struct cred *cr)
251 {
252 prnode_t *pnp = (prnode_t *)vfsp->vfs_data;
253 vnode_t *vp = PTOV(pnp);
254
255 mutex_enter(&pr_mount_lock);
256 if (secpolicy_fs_unmount(cr, vfsp) != 0) {
257 mutex_exit(&pr_mount_lock);
258 return (EPERM);
259 }
260
261 /*
262 * forced unmount is not supported by this file system
263 * and thus, ENOTSUP, is being returned.
264 */
265 if (flag & MS_FORCE) {
266 mutex_exit(&pr_mount_lock);
267 return (ENOTSUP);
268 }
269
270 /*
271 * Ensure that no /proc vnodes are in use on this mount point.
272 */
273 mutex_enter(&vp->v_lock);
274 if (vp->v_count > 1) {
275 mutex_exit(&vp->v_lock);
276 mutex_exit(&pr_mount_lock);
277 return (EBUSY);
278 }
279
280 mutex_exit(&vp->v_lock);
281 mutex_exit(&pr_mount_lock);
282 vn_invalid(vp);
283 vn_free(vp);
284 kmem_free(pnp, sizeof (*pnp));
285 return (0);
286 }
287
288 /* ARGSUSED */
289 static int
290 prroot(struct vfs *vfsp, struct vnode **vpp)
291 {
292 vnode_t *vp = PTOV((prnode_t *)vfsp->vfs_data);
293
294 VN_HOLD(vp);
295 *vpp = vp;
296 return (0);
297 }
298
299 static int
300 prstatvfs(struct vfs *vfsp, struct statvfs64 *sp)
301 {
302 int n;
303 dev32_t d32;
304 extern uint_t nproc;
305
306 n = v.v_proc - nproc;
307
308 bzero((caddr_t)sp, sizeof (*sp));
309 sp->f_bsize = DEV_BSIZE;
310 sp->f_frsize = DEV_BSIZE;
311 sp->f_blocks = (fsblkcnt64_t)0;
312 sp->f_bfree = (fsblkcnt64_t)0;
313 sp->f_bavail = (fsblkcnt64_t)0;
314 sp->f_files = (fsfilcnt64_t)v.v_proc + 2;
315 sp->f_ffree = (fsfilcnt64_t)n;
316 sp->f_favail = (fsfilcnt64_t)n;
317 (void) cmpldev(&d32, vfsp->vfs_dev);
318 sp->f_fsid = d32;
319 (void) strcpy(sp->f_basetype, vfssw[procfstype].vsw_name);
320 sp->f_flag = vf_to_stf(vfsp->vfs_flag);
321 sp->f_namemax = 64; /* quite arbitrary */
322 bzero(sp->f_fstr, sizeof (sp->f_fstr));
323 (void) strcpy(sp->f_fstr, "/proc");
324 (void) strcpy(&sp->f_fstr[6], "/proc");
325 return (0);
326 }