1 /* $NetBSD: ptyfs_vfsops.c,v 1.38 2009/01/11 02:45:51 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated 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 */ 35 36 /* 37 * Pseudo-tty Filesystem 38 */ 39 40 #include <sys/cdefs.h> 41 __KERNEL_RCSID(0, "$NetBSD: ptyfs_vfsops.c,v 1.38 2009/01/11 02:45:51 christos Exp $"); 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/sysctl.h> 46 #include <sys/conf.h> 47 #include <sys/proc.h> 48 #include <sys/vnode.h> 49 #include <sys/mount.h> 50 #include <sys/namei.h> 51 #include <sys/stat.h> 52 #include <sys/dirent.h> 53 #include <sys/malloc.h> 54 #include <sys/syslog.h> 55 #include <sys/select.h> 56 #include <sys/filedesc.h> 57 #include <sys/tty.h> 58 #include <sys/pty.h> 59 #include <sys/kauth.h> 60 #include <sys/module.h> 61 62 #include <fs/ptyfs/ptyfs.h> 63 #include <miscfs/genfs/genfs.h> 64 #include <miscfs/specfs/specdev.h> 65 66 MODULE(MODULE_CLASS_VFS, ptyfs, NULL); 67 68 MALLOC_JUSTDEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures"); 69 MALLOC_JUSTDEFINE(M_PTYFSTMP, "ptyfs temp", "ptyfs temporary structures"); 70 71 VFS_PROTOS(ptyfs); 72 73 static struct sysctllog *ptyfs_sysctl_log; 74 75 static int ptyfs__allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 76 dev_t, char); 77 static int ptyfs__makename(struct ptm_pty *, struct lwp *, char *, size_t, 78 dev_t, char); 79 static void ptyfs__getvattr(struct ptm_pty *, struct lwp *, struct vattr *); 80 81 /* 82 * ptm glue: When we mount, we make ptm point to us. 83 */ 84 struct ptm_pty *ptyfs_save_ptm; 85 static int ptyfs_count; 86 87 struct ptm_pty ptm_ptyfspty = { 88 ptyfs__allocvp, 89 ptyfs__makename, 90 ptyfs__getvattr, 91 NULL 92 }; 93 94 static int 95 ptyfs__makename(struct ptm_pty *pt, struct lwp *l, char *tbuf, size_t bufsiz, 96 dev_t dev, char ms) 97 { 98 struct mount *mp = pt->arg; 99 size_t len; 100 101 switch (ms) { 102 case 'p': 103 /* We don't provide access to the master, should we? */ 104 len = snprintf(tbuf, bufsiz, "/dev/null"); 105 break; 106 case 't': 107 len = snprintf(tbuf, bufsiz, "%s/%llu", 108 mp->mnt_stat.f_mntonname, 109 (unsigned long long)minor(dev)); 110 break; 111 default: 112 return EINVAL; 113 } 114 115 return len >= bufsiz ? ENOSPC : 0; 116 } 117 118 119 static int 120 /*ARGSUSED*/ 121 ptyfs__allocvp(struct ptm_pty *pt, struct lwp *l, struct vnode **vpp, 122 dev_t dev, char ms) 123 { 124 struct mount *mp = pt->arg; 125 ptyfstype type; 126 127 switch (ms) { 128 case 'p': 129 type = PTYFSptc; 130 break; 131 case 't': 132 type = PTYFSpts; 133 break; 134 default: 135 return EINVAL; 136 } 137 138 return ptyfs_allocvp(mp, vpp, type, minor(dev), l); 139 } 140 141 142 static void 143 ptyfs__getvattr(struct ptm_pty *pt, struct lwp *l, struct vattr *vattr) 144 { 145 struct mount *mp = pt->arg; 146 struct ptyfsmount *pmnt = VFSTOPTY(mp); 147 VATTR_NULL(vattr); 148 /* get real uid */ 149 vattr->va_uid = kauth_cred_getuid(l->l_cred); 150 vattr->va_gid = pmnt->pmnt_gid; 151 vattr->va_mode = pmnt->pmnt_mode; 152 } 153 154 155 void 156 ptyfs_init(void) 157 { 158 159 malloc_type_attach(M_PTYFSMNT); 160 malloc_type_attach(M_PTYFSTMP); 161 ptyfs_hashinit(); 162 } 163 164 void 165 ptyfs_reinit(void) 166 { 167 ptyfs_hashreinit(); 168 } 169 170 void 171 ptyfs_done(void) 172 { 173 174 ptyfs_hashdone(); 175 malloc_type_detach(M_PTYFSTMP); 176 malloc_type_detach(M_PTYFSMNT); 177 } 178 179 /* 180 * Mount the Pseudo tty params filesystem 181 */ 182 int 183 ptyfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 184 { 185 struct lwp *l = curlwp; 186 int error = 0; 187 struct ptyfsmount *pmnt; 188 struct ptyfs_args *args = data; 189 190 if (*data_len < sizeof *args) 191 return EINVAL; 192 193 if (UIO_MX & (UIO_MX - 1)) { 194 log(LOG_ERR, "ptyfs: invalid directory entry size"); 195 return EINVAL; 196 } 197 198 if (mp->mnt_flag & MNT_GETARGS) { 199 pmnt = VFSTOPTY(mp); 200 if (pmnt == NULL) 201 return EIO; 202 args->version = PTYFS_ARGSVERSION; 203 args->mode = pmnt->pmnt_mode; 204 args->gid = pmnt->pmnt_gid; 205 *data_len = sizeof *args; 206 return 0; 207 } 208 209 /* Don't allow more than one mount */ 210 if (ptyfs_count) 211 return EBUSY; 212 213 if (mp->mnt_flag & MNT_UPDATE) 214 return EOPNOTSUPP; 215 216 if (args->version != PTYFS_ARGSVERSION) 217 return EINVAL; 218 219 pmnt = malloc(sizeof(struct ptyfsmount), M_PTYFSMNT, M_WAITOK); 220 221 mp->mnt_data = pmnt; 222 pmnt->pmnt_gid = args->gid; 223 pmnt->pmnt_mode = args->mode; 224 mp->mnt_flag |= MNT_LOCAL; 225 vfs_getnewfsid(mp); 226 227 if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs", 228 UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) { 229 free(pmnt, M_PTYFSMNT); 230 return error; 231 } 232 233 /* Point pty access to us */ 234 235 ptm_ptyfspty.arg = mp; 236 ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty); 237 ptyfs_count++; 238 return 0; 239 } 240 241 /*ARGSUSED*/ 242 int 243 ptyfs_start(struct mount *mp, int flags) 244 { 245 return 0; 246 } 247 248 /*ARGSUSED*/ 249 int 250 ptyfs_unmount(struct mount *mp, int mntflags) 251 { 252 int error; 253 int flags = 0; 254 255 if (mntflags & MNT_FORCE) 256 flags |= FORCECLOSE; 257 258 if ((error = vflush(mp, 0, flags)) != 0) 259 return (error); 260 261 /* Restore where pty access was pointing */ 262 (void)pty_sethandler(ptyfs_save_ptm); 263 ptyfs_save_ptm = NULL; 264 ptm_ptyfspty.arg = NULL; 265 266 /* 267 * Finally, throw away the ptyfsmount structure 268 */ 269 free(mp->mnt_data, M_PTYFSMNT); 270 mp->mnt_data = NULL; 271 ptyfs_count--; 272 273 return 0; 274 } 275 276 int 277 ptyfs_root(struct mount *mp, struct vnode **vpp) 278 { 279 /* setup "." */ 280 return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL); 281 } 282 283 /*ARGSUSED*/ 284 int 285 ptyfs_statvfs(struct mount *mp, struct statvfs *sbp) 286 { 287 sbp->f_bsize = DEV_BSIZE; 288 sbp->f_frsize = DEV_BSIZE; 289 sbp->f_iosize = DEV_BSIZE; 290 sbp->f_blocks = 2; /* 1K to keep df happy */ 291 sbp->f_bfree = 0; 292 sbp->f_bavail = 0; 293 sbp->f_bresvd = 0; 294 sbp->f_files = 1024; /* XXX lie */ 295 sbp->f_ffree = 128; /* XXX lie */ 296 sbp->f_favail = 128; /* XXX lie */ 297 sbp->f_fresvd = 0; 298 sbp->f_namemax = MAXNAMLEN; 299 copy_statvfs_info(sbp, mp); 300 return 0; 301 } 302 303 /*ARGSUSED*/ 304 int 305 ptyfs_sync(struct mount *mp, int waitfor, 306 kauth_cred_t uc) 307 { 308 return 0; 309 } 310 311 /* 312 * Kernfs flat namespace lookup. 313 * Currently unsupported. 314 */ 315 /*ARGSUSED*/ 316 int 317 ptyfs_vget(struct mount *mp, ino_t ino, 318 struct vnode **vpp) 319 { 320 return EOPNOTSUPP; 321 } 322 323 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc; 324 325 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = { 326 &ptyfs_vnodeop_opv_desc, 327 NULL, 328 }; 329 330 struct vfsops ptyfs_vfsops = { 331 MOUNT_PTYFS, 332 sizeof (struct ptyfs_args), 333 ptyfs_mount, 334 ptyfs_start, 335 ptyfs_unmount, 336 ptyfs_root, 337 (void *)eopnotsupp, /* vfs_quotactl */ 338 ptyfs_statvfs, 339 ptyfs_sync, 340 ptyfs_vget, 341 (void *)eopnotsupp, /* vfs_fhtovp */ 342 (void *)eopnotsupp, /* vfs_vptofp */ 343 ptyfs_init, 344 ptyfs_reinit, 345 ptyfs_done, 346 NULL, /* vfs_mountroot */ 347 (void *)eopnotsupp, 348 (void *)eopnotsupp, 349 (void *)eopnotsupp, /* vfs_suspendctl */ 350 genfs_renamelock_enter, 351 genfs_renamelock_exit, 352 (void *)eopnotsupp, 353 ptyfs_vnodeopv_descs, 354 0, 355 { NULL, NULL }, 356 }; 357 358 static int 359 ptyfs_modcmd(modcmd_t cmd, void *arg) 360 { 361 int error; 362 363 switch (cmd) { 364 case MODULE_CMD_INIT: 365 error = vfs_attach(&ptyfs_vfsops); 366 if (error != 0) 367 break; 368 sysctl_createv(&ptyfs_sysctl_log, 0, NULL, NULL, 369 CTLFLAG_PERMANENT, 370 CTLTYPE_NODE, "vfs", NULL, 371 NULL, 0, NULL, 0, 372 CTL_VFS, CTL_EOL); 373 sysctl_createv(&ptyfs_sysctl_log, 0, NULL, NULL, 374 CTLFLAG_PERMANENT, 375 CTLTYPE_NODE, "ptyfs", 376 SYSCTL_DESCR("Pty file system"), 377 NULL, 0, NULL, 0, 378 CTL_VFS, 23, CTL_EOL); 379 /* 380 * XXX the "23" above could be dynamic, thereby eliminating 381 * one more instance of the "number to vfs" mapping problem, 382 * but "23" is the order as taken from sys/mount.h 383 */ 384 break; 385 case MODULE_CMD_FINI: 386 error = vfs_detach(&ptyfs_vfsops); 387 if (error != 0) 388 break; 389 sysctl_teardown(&ptyfs_sysctl_log); 390 break; 391 default: 392 error = ENOTTY; 393 break; 394 } 395 396 return (error); 397 } 398