1 /* $NetBSD: procfs_vfsops.c,v 1.91 2014/04/16 18:55:19 maxv 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 1.91 2014/04/16 18:55:19 maxv 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 (args == NULL) 134 return EINVAL; 135 136 if (UIO_MX & (UIO_MX-1)) { 137 log(LOG_ERR, "procfs: invalid directory entry size"); 138 return (EINVAL); 139 } 140 141 if (mp->mnt_flag & MNT_GETARGS) { 142 if (*data_len < sizeof *args) 143 return EINVAL; 144 145 pmnt = VFSTOPROC(mp); 146 if (pmnt == NULL) 147 return EIO; 148 args->version = PROCFS_ARGSVERSION; 149 args->flags = pmnt->pmnt_flags; 150 *data_len = sizeof *args; 151 return 0; 152 } 153 154 if (mp->mnt_flag & MNT_UPDATE) 155 return (EOPNOTSUPP); 156 157 if (*data_len >= sizeof *args && args->version != PROCFS_ARGSVERSION) 158 return EINVAL; 159 160 pmnt = kmem_zalloc(sizeof(struct procfsmount), KM_SLEEP); 161 162 mp->mnt_stat.f_namemax = PROCFS_MAXNAMLEN; 163 mp->mnt_flag |= MNT_LOCAL; 164 mp->mnt_data = pmnt; 165 vfs_getnewfsid(mp); 166 167 error = set_statvfs_info(path, UIO_USERSPACE, "procfs", UIO_SYSSPACE, 168 mp->mnt_op->vfs_name, mp, l); 169 pmnt->pmnt_exechook = exechook_establish(procfs_revoke_vnodes, mp); 170 if (*data_len >= sizeof *args) 171 pmnt->pmnt_flags = args->flags; 172 else 173 pmnt->pmnt_flags = 0; 174 175 mp->mnt_iflag |= IMNT_MPSAFE; 176 return error; 177 } 178 179 /* 180 * unmount system call 181 */ 182 int 183 procfs_unmount(struct mount *mp, int mntflags) 184 { 185 int error; 186 int flags = 0; 187 188 if (mntflags & MNT_FORCE) 189 flags |= FORCECLOSE; 190 191 if ((error = vflush(mp, 0, flags)) != 0) 192 return (error); 193 194 exechook_disestablish(VFSTOPROC(mp)->pmnt_exechook); 195 196 kmem_free(mp->mnt_data, sizeof(struct procfsmount)); 197 mp->mnt_data = NULL; 198 199 return 0; 200 } 201 202 int 203 procfs_root(struct mount *mp, struct vnode **vpp) 204 { 205 int error; 206 207 error = procfs_allocvp(mp, vpp, 0, PFSroot, -1, NULL); 208 if (error == 0) { 209 error = vn_lock(*vpp, LK_EXCLUSIVE); 210 if (error != 0) { 211 vrele(*vpp); 212 *vpp = NULL; 213 } 214 } 215 216 return error; 217 } 218 219 /* ARGSUSED */ 220 int 221 procfs_start(struct mount *mp, int flags) 222 { 223 224 return (0); 225 } 226 227 /* 228 * Get file system statistics. 229 */ 230 int 231 procfs_statvfs(struct mount *mp, struct statvfs *sbp) 232 { 233 234 genfs_statvfs(mp, sbp); 235 236 sbp->f_bsize = PAGE_SIZE; 237 sbp->f_frsize = PAGE_SIZE; 238 sbp->f_iosize = PAGE_SIZE; 239 sbp->f_blocks = 1; 240 sbp->f_files = maxproc; /* approx */ 241 sbp->f_ffree = maxproc - nprocs; /* approx */ 242 sbp->f_favail = maxproc - nprocs; /* approx */ 243 244 return (0); 245 } 246 247 /*ARGSUSED*/ 248 int 249 procfs_sync( 250 struct mount *mp, 251 int waitfor, 252 kauth_cred_t uc) 253 { 254 255 return (0); 256 } 257 258 /*ARGSUSED*/ 259 int 260 procfs_vget(struct mount *mp, ino_t ino, 261 struct vnode **vpp) 262 { 263 return (EOPNOTSUPP); 264 } 265 266 void 267 procfs_init(void) 268 { 269 procfs_hashinit(); 270 } 271 272 void 273 procfs_reinit(void) 274 { 275 procfs_hashreinit(); 276 } 277 278 void 279 procfs_done(void) 280 { 281 procfs_hashdone(); 282 } 283 284 extern const struct vnodeopv_desc procfs_vnodeop_opv_desc; 285 286 const struct vnodeopv_desc * const procfs_vnodeopv_descs[] = { 287 &procfs_vnodeop_opv_desc, 288 NULL, 289 }; 290 291 struct vfsops procfs_vfsops = { 292 .vfs_name = MOUNT_PROCFS, 293 .vfs_min_mount_data = sizeof (struct procfs_args), 294 .vfs_mount = procfs_mount, 295 .vfs_start = procfs_start, 296 .vfs_unmount = procfs_unmount, 297 .vfs_root = procfs_root, 298 .vfs_quotactl = (void *)eopnotsupp, 299 .vfs_statvfs = procfs_statvfs, 300 .vfs_sync = procfs_sync, 301 .vfs_vget = procfs_vget, 302 .vfs_fhtovp = (void *)eopnotsupp, 303 .vfs_vptofh = (void *)eopnotsupp, 304 .vfs_init = procfs_init, 305 .vfs_reinit = procfs_reinit, 306 .vfs_done = procfs_done, 307 .vfs_snapshot = (void *)eopnotsupp, 308 .vfs_extattrctl = vfs_stdextattrctl, 309 .vfs_suspendctl = (void *)eopnotsupp, 310 .vfs_renamelock_enter = genfs_renamelock_enter, 311 .vfs_renamelock_exit = genfs_renamelock_exit, 312 .vfs_fsync = (void *)eopnotsupp, 313 .vfs_opv_descs = procfs_vnodeopv_descs 314 }; 315 316 static int 317 procfs_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, 318 void *arg0, void *arg1, void *arg2, void *arg3) 319 { 320 struct proc *p; 321 struct pfsnode *pfs; 322 enum kauth_process_req req; 323 int result; 324 325 result = KAUTH_RESULT_DEFER; 326 p = arg0; 327 pfs = arg1; 328 req = (enum kauth_process_req)(unsigned long)arg2; 329 330 if (action != KAUTH_PROCESS_PROCFS) 331 return result; 332 333 /* Privileged; let secmodel handle that. */ 334 if (req == KAUTH_REQ_PROCESS_PROCFS_CTL) 335 return result; 336 337 switch (pfs->pfs_type) { 338 case PFSregs: 339 case PFSfpregs: 340 case PFSmem: 341 if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) || 342 ISSET(p->p_flag, PK_SUGID)) 343 break; 344 345 /*FALLTHROUGH*/ 346 default: 347 result = KAUTH_RESULT_ALLOW; 348 break; 349 } 350 351 return result; 352 } 353 354 355 static int 356 procfs_modcmd(modcmd_t cmd, void *arg) 357 { 358 int error; 359 360 switch (cmd) { 361 case MODULE_CMD_INIT: 362 error = vfs_attach(&procfs_vfsops); 363 if (error != 0) 364 break; 365 sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL, 366 CTLFLAG_PERMANENT, 367 CTLTYPE_NODE, "procfs", 368 SYSCTL_DESCR("Process file system"), 369 NULL, 0, NULL, 0, 370 CTL_VFS, 12, CTL_EOL); 371 /* 372 * XXX the "12" above could be dynamic, thereby eliminating 373 * one more instance of the "number to vfs" mapping problem, 374 * but "12" is the order as taken from sys/mount.h 375 */ 376 377 procfs_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS, 378 procfs_listener_cb, NULL); 379 380 break; 381 case MODULE_CMD_FINI: 382 error = vfs_detach(&procfs_vfsops); 383 if (error != 0) 384 break; 385 sysctl_teardown(&procfs_sysctl_log); 386 kauth_unlisten_scope(procfs_listener); 387 break; 388 default: 389 error = ENOTTY; 390 break; 391 } 392 393 return (error); 394 } 395