sys/miscfs/procfs/procfs_vfsops.c

   1 /*      $NetBSD: procfs_vfsops.c,v 1.84 2009/10/02 23:00:02 elad Exp $  */
   2
   3 /*
   4  * Copyright (c) 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Jan-Simon Pendry.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)procfs_vfsops.c     8.7 (Berkeley) 5/10/95
  35  */
  36
  37 /*
  38  * Copyright (c) 1993 Jan-Simon Pendry
  39  *
  40  * This code is derived from software contributed to Berkeley by
  41  * Jan-Simon Pendry.
  42  *
  43  * Redistribution and use in source and binary forms, with or without
  44  * modification, are permitted provided that the following conditions
  45  * are met:
  46  * 1. Redistributions of source code must retain the above copyright
  47  *    notice, this list of conditions and the following disclaimer.
  48  * 2. Redistributions in binary form must reproduce the above copyright
  49  *    notice, this list of conditions and the following disclaimer in the
  50  *    documentation and/or other materials provided with the distribution.
  51  * 3. All advertising materials mentioning features or use of this software
  52  *    must display the following acknowledgement:
  53  *      This product includes software developed by the University of
  54  *      California, Berkeley and its contributors.
  55  * 4. Neither the name of the University nor the names of its contributors
  56  *    may be used to endorse or promote products derived from this software
  57  *    without specific prior written permission.
  58  *
  59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  69  * SUCH DAMAGE.
  70  *
  71  *      @(#)procfs_vfsops.c     8.7 (Berkeley) 5/10/95
  72  */
  73
  74 /*
  75  * procfs VFS interface
  76  */
  77
  78 #include <sys/cdefs.h>
  79 __KERNEL_RCSID(0, "$NetBSD: procfs_vfsops.c,v 1.84 2009/10/02 23:00:02 elad Exp $");
  80
  81 #if defined(_KERNEL_OPT)
  82 #include "opt_compat_netbsd.h"
  83 #endif
  84
  85 #include <sys/param.h>
  86 #include <sys/time.h>
  87 #include <sys/kernel.h>
  88 #include <sys/systm.h>
  89 #include <sys/sysctl.h>
  90 #include <sys/proc.h>
  91 #include <sys/buf.h>
  92 #include <sys/syslog.h>
  93 #include <sys/mount.h>
  94 #include <sys/dirent.h>
  95 #include <sys/signalvar.h>
  96 #include <sys/vnode.h>
  97 #include <sys/malloc.h>
  98 #include <sys/kauth.h>
  99 #include <sys/module.h>
 100
 101 #include <miscfs/genfs/genfs.h>
 102
 103 #include <miscfs/procfs/procfs.h>
 104
 105 #include <uvm/uvm_extern.h>                     /* for PAGE_SIZE */
 106
 107 MODULE(MODULE_CLASS_VFS, procfs, NULL);
 108
 109 VFS_PROTOS(procfs);
 110
 111 static struct sysctllog *procfs_sysctl_log;
 112
 113 static kauth_listener_t procfs_listener;
 114
 115 /*
 116  * VFS Operations.
 117  *
 118  * mount system call
 119  */
 120 /* ARGSUSED */
 121 int
 122 procfs_mount(
 123     struct mount *mp,
 124     const char *path,
 125     void *data,
 126     size_t *data_len)
 127 {
 128         struct lwp *l = curlwp;
 129         struct procfsmount *pmnt;
 130         struct procfs_args *args = data;
 131         int error;
 132
 133         if (UIO_MX & (UIO_MX-1)) {
 134                 log(LOG_ERR, "procfs: invalid directory entry size");
 135                 return (EINVAL);
 136         }
 137
 138         if (mp->mnt_flag & MNT_GETARGS) {
 139                 if (*data_len < sizeof *args)
 140                         return EINVAL;
 141
 142                 pmnt = VFSTOPROC(mp);
 143                 if (pmnt == NULL)
 144                         return EIO;
 145                 args->version = PROCFS_ARGSVERSION;
 146                 args->flags = pmnt->pmnt_flags;
 147                 *data_len = sizeof *args;
 148                 return 0;
 149         }
 150
 151         if (mp->mnt_flag & MNT_UPDATE)
 152                 return (EOPNOTSUPP);
 153
 154         if (*data_len >= sizeof *args && args->version != PROCFS_ARGSVERSION)
 155                 return EINVAL;
 156
 157         pmnt = (struct procfsmount *) malloc(sizeof(struct procfsmount),
 158             M_UFSMNT, M_WAITOK);   /* XXX need new malloc type */
 159
 160         mp->mnt_stat.f_namemax = MAXNAMLEN;
 161         mp->mnt_flag |= MNT_LOCAL;
 162         mp->mnt_data = pmnt;
 163         vfs_getnewfsid(mp);
 164
 165         error = set_statvfs_info(path, UIO_USERSPACE, "procfs", UIO_SYSSPACE,
 166             mp->mnt_op->vfs_name, mp, l);
 167         pmnt->pmnt_exechook = exechook_establish(procfs_revoke_vnodes, mp);
 168         if (*data_len >= sizeof *args)
 169                 pmnt->pmnt_flags = args->flags;
 170         else
 171                 pmnt->pmnt_flags = 0;
 172
 173         mp->mnt_iflag |= IMNT_MPSAFE;
 174         return error;
 175 }
 176
 177 /*
 178  * unmount system call
 179  */
 180 int
 181 procfs_unmount(struct mount *mp, int mntflags)
 182 {
 183         int error;
 184         int flags = 0;
 185
 186         if (mntflags & MNT_FORCE)
 187                 flags |= FORCECLOSE;
 188
 189         if ((error = vflush(mp, 0, flags)) != 0)
 190                 return (error);
 191
 192         exechook_disestablish(VFSTOPROC(mp)->pmnt_exechook);
 193
 194         free(mp->mnt_data, M_UFSMNT);
 195         mp->mnt_data = NULL;
 196
 197         return (0);
 198 }
 199
 200 int
 201 procfs_root(struct mount *mp, struct vnode **vpp)
 202 {
 203
 204         return (procfs_allocvp(mp, vpp, 0, PFSroot, -1, NULL));
 205 }
 206
 207 /* ARGSUSED */
 208 int
 209 procfs_start(struct mount *mp, int flags)
 210 {
 211
 212         return (0);
 213 }
 214
 215 /*
 216  * Get file system statistics.
 217  */
 218 int
 219 procfs_statvfs(struct mount *mp, struct statvfs *sbp)
 220 {
 221
 222         genfs_statvfs(mp, sbp);
 223
 224         sbp->f_bsize = PAGE_SIZE;
 225         sbp->f_frsize = PAGE_SIZE;
 226         sbp->f_iosize = PAGE_SIZE;
 227         sbp->f_blocks = 1;
 228         sbp->f_files = maxproc;                 /* approx */
 229         sbp->f_ffree = maxproc - nprocs;        /* approx */
 230         sbp->f_favail = maxproc - nprocs;       /* approx */
 231
 232         return (0);
 233 }
 234
 235 /*ARGSUSED*/
 236 int
 237 procfs_sync(
 238     struct mount *mp,
 239     int waitfor,
 240     kauth_cred_t uc)
 241 {
 242
 243         return (0);
 244 }
 245
 246 /*ARGSUSED*/
 247 int
 248 procfs_vget(struct mount *mp, ino_t ino,
 249     struct vnode **vpp)
 250 {
 251         return (EOPNOTSUPP);
 252 }
 253
 254 void
 255 procfs_init(void)
 256 {
 257         procfs_hashinit();
 258 }
 259
 260 void
 261 procfs_reinit(void)
 262 {
 263         procfs_hashreinit();
 264 }
 265
 266 void
 267 procfs_done(void)
 268 {
 269         procfs_hashdone();
 270 }
 271
 272 extern const struct vnodeopv_desc procfs_vnodeop_opv_desc;
 273
 274 const struct vnodeopv_desc * const procfs_vnodeopv_descs[] = {
 275         &procfs_vnodeop_opv_desc,
 276         NULL,
 277 };
 278
 279 struct vfsops procfs_vfsops = {
 280         MOUNT_PROCFS,
 281         sizeof (struct procfs_args),
 282         procfs_mount,
 283         procfs_start,
 284         procfs_unmount,
 285         procfs_root,
 286         (void *)eopnotsupp,             /* vfs_quotactl */
 287         procfs_statvfs,
 288         procfs_sync,
 289         procfs_vget,
 290         (void *)eopnotsupp,             /* vfs_fhtovp */
 291         (void *)eopnotsupp,             /* vfs_vptofh */
 292         procfs_init,
 293         procfs_reinit,
 294         procfs_done,
 295         NULL,                           /* vfs_mountroot */
 296         (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
 297         vfs_stdextattrctl,
 298         (void *)eopnotsupp,             /* vfs_suspendctl */
 299         genfs_renamelock_enter,
 300         genfs_renamelock_exit,
 301         (void *)eopnotsupp,
 302         procfs_vnodeopv_descs,
 303         0,
 304         { NULL, NULL },
 305 };
 306
 307 static int
 308 procfs_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
 309     void *arg0, void *arg1, void *arg2, void *arg3)
 310 {
 311         struct proc *p;
 312         struct pfsnode *pfs;
 313         enum kauth_process_req req;
 314         int result;
 315
 316         result = KAUTH_RESULT_DEFER;
 317         p = arg0;
 318         pfs = arg1;
 319         req = (enum kauth_process_req)(unsigned long)arg2;
 320
 321         if (action != KAUTH_PROCESS_PROCFS)
 322                 return result;
 323
 324         /* Privileged; let secmodel handle that. */
 325         if (req == KAUTH_REQ_PROCESS_PROCFS_CTL)
 326                 return result;
 327
 328         switch (pfs->pfs_type) {
 329         case PFSregs:
 330         case PFSfpregs:
 331         case PFSmem:
 332                 if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
 333                     ISSET(p->p_flag, PK_SUGID))
 334                         break;
 335
 336                 /*FALLTHROUGH*/
 337         default:
 338                 result = KAUTH_RESULT_ALLOW;
 339                 break;
 340         }
 341
 342         return result;
 343 }
 344
 345
 346 static int
 347 procfs_modcmd(modcmd_t cmd, void *arg)
 348 {
 349         int error;
 350
 351         switch (cmd) {
 352         case MODULE_CMD_INIT:
 353                 error = vfs_attach(&procfs_vfsops);
 354                 if (error != 0)
 355                         break;
 356                 sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
 357                                CTLFLAG_PERMANENT,
 358                                CTLTYPE_NODE, "vfs", NULL,
 359                                NULL, 0, NULL, 0,
 360                                CTL_VFS, CTL_EOL);
 361                 sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
 362                                CTLFLAG_PERMANENT,
 363                                CTLTYPE_NODE, "procfs",
 364                                SYSCTL_DESCR("Process file system"),
 365                                NULL, 0, NULL, 0,
 366                                CTL_VFS, 12, CTL_EOL);
 367                 /*
 368                  * XXX the "12" above could be dynamic, thereby eliminating
 369                  * one more instance of the "number to vfs" mapping problem,
 370                  * but "12" is the order as taken from sys/mount.h
 371                  */
 372
 373                 procfs_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
 374                     procfs_listener_cb, NULL);
 375
 376                 break;
 377         case MODULE_CMD_FINI:
 378                 error = vfs_detach(&procfs_vfsops);
 379                 if (error != 0)
 380                         break;
 381                 sysctl_teardown(&procfs_sysctl_log);
 382                 kauth_unlisten_scope(procfs_listener);
 383                 break;
 384         default:
 385                 error = ENOTTY;
 386                 break;
 387         }
 388
 389         return (error);
 390 }