1 /* $NetBSD: ptyfs_vfsops.c,v 1.42 2010/01/08 11:35:09 pooka 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 1.42 2010/01/08 11:35:09 pooka 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 const char * 95 ptyfs__getpath(struct lwp *l, const struct mount *mp) 96 { 97 #define MAXBUF (sizeof(mp->mnt_stat.f_mntonname) + 32) 98 struct cwdinfo *cwdi = l->l_proc->p_cwdi; 99 char *buf; 100 const char *rv; 101 size_t len; 102 char *bp; 103 int error; 104 struct ptyfsmount *pmnt = mp->mnt_data; 105 106 rv = mp->mnt_stat.f_mntonname; 107 if (cwdi->cwdi_rdir == NULL || 108 (pmnt->pmnt_flags & PTYFSMNT_CHROOT) == 0) 109 return rv; 110 111 buf = malloc(MAXBUF, M_TEMP, M_WAITOK); 112 bp = buf + MAXBUF; 113 *--bp = '\0'; 114 error = getcwd_common(cwdi->cwdi_rdir, rootvnode, &bp, 115 buf, MAXBUF / 2, 0, l); 116 if (error) /* XXX */ 117 goto out; 118 119 len = strlen(bp); 120 if (len < sizeof(mp->mnt_stat.f_mntonname)) /* XXX */ 121 rv += len; 122 out: 123 free(buf, M_TEMP); 124 return rv; 125 } 126 127 static int 128 ptyfs__makename(struct ptm_pty *pt, struct lwp *l, char *tbuf, size_t bufsiz, 129 dev_t dev, char ms) 130 { 131 struct mount *mp = pt->arg; 132 size_t len; 133 134 switch (ms) { 135 case 'p': 136 /* We don't provide access to the master, should we? */ 137 len = snprintf(tbuf, bufsiz, "/dev/null"); 138 break; 139 case 't': 140 len = snprintf(tbuf, bufsiz, "%s/%llu", ptyfs__getpath(l, mp), 141 (unsigned long long)minor(dev)); 142 break; 143 default: 144 return EINVAL; 145 } 146 147 return len >= bufsiz ? ENOSPC : 0; 148 } 149 150 151 static int 152 /*ARGSUSED*/ 153 ptyfs__allocvp(struct ptm_pty *pt, struct lwp *l, struct vnode **vpp, 154 dev_t dev, char ms) 155 { 156 struct mount *mp = pt->arg; 157 ptyfstype type; 158 159 switch (ms) { 160 case 'p': 161 type = PTYFSptc; 162 break; 163 case 't': 164 type = PTYFSpts; 165 break; 166 default: 167 return EINVAL; 168 } 169 170 return ptyfs_allocvp(mp, vpp, type, minor(dev), l); 171 } 172 173 174 static void 175 ptyfs__getvattr(struct ptm_pty *pt, struct lwp *l, struct vattr *vattr) 176 { 177 struct mount *mp = pt->arg; 178 struct ptyfsmount *pmnt = VFSTOPTY(mp); 179 vattr_null(vattr); 180 /* get real uid */ 181 vattr->va_uid = kauth_cred_getuid(l->l_cred); 182 vattr->va_gid = pmnt->pmnt_gid; 183 vattr->va_mode = pmnt->pmnt_mode; 184 } 185 186 187 void 188 ptyfs_init(void) 189 { 190 191 malloc_type_attach(M_PTYFSMNT); 192 malloc_type_attach(M_PTYFSTMP); 193 ptyfs_hashinit(); 194 } 195 196 void 197 ptyfs_reinit(void) 198 { 199 ptyfs_hashreinit(); 200 } 201 202 void 203 ptyfs_done(void) 204 { 205 206 ptyfs_hashdone(); 207 malloc_type_detach(M_PTYFSTMP); 208 malloc_type_detach(M_PTYFSMNT); 209 } 210 211 #define OSIZE sizeof(struct { int f; gid_t g; mode_t m; }) 212 /* 213 * Mount the Pseudo tty params filesystem 214 */ 215 int 216 ptyfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 217 { 218 struct lwp *l = curlwp; 219 int error = 0; 220 struct ptyfsmount *pmnt; 221 struct ptyfs_args *args = data; 222 223 if (*data_len != sizeof *args && *data_len != OSIZE) 224 return EINVAL; 225 226 if (UIO_MX & (UIO_MX - 1)) { 227 log(LOG_ERR, "ptyfs: invalid directory entry size"); 228 return EINVAL; 229 } 230 231 if (mp->mnt_flag & MNT_GETARGS) { 232 pmnt = VFSTOPTY(mp); 233 if (pmnt == NULL) 234 return EIO; 235 args->mode = pmnt->pmnt_mode; 236 args->gid = pmnt->pmnt_gid; 237 if (args->version >= PTYFS_ARGSVERSION) { 238 args->flags = pmnt->pmnt_flags; 239 *data_len = sizeof *args; 240 } else { 241 *data_len = OSIZE; 242 } 243 return 0; 244 } 245 246 /* Don't allow more than one mount */ 247 if (ptyfs_count) 248 return EBUSY; 249 250 if (mp->mnt_flag & MNT_UPDATE) 251 return EOPNOTSUPP; 252 253 if (args->version > PTYFS_ARGSVERSION) 254 return EINVAL; 255 256 pmnt = malloc(sizeof(struct ptyfsmount), M_PTYFSMNT, M_WAITOK); 257 258 mp->mnt_data = pmnt; 259 pmnt->pmnt_gid = args->gid; 260 pmnt->pmnt_mode = args->mode; 261 if (args->version >= PTYFS_ARGSVERSION) 262 pmnt->pmnt_flags = args->flags; 263 else 264 pmnt->pmnt_flags = 0; 265 mp->mnt_flag |= MNT_LOCAL; 266 vfs_getnewfsid(mp); 267 268 if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs", 269 UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) { 270 free(pmnt, M_PTYFSMNT); 271 return error; 272 } 273 274 /* Point pty access to us */ 275 276 ptm_ptyfspty.arg = mp; 277 ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty); 278 ptyfs_count++; 279 return 0; 280 } 281 282 /*ARGSUSED*/ 283 int 284 ptyfs_start(struct mount *mp, int flags) 285 { 286 return 0; 287 } 288 289 /*ARGSUSED*/ 290 int 291 ptyfs_unmount(struct mount *mp, int mntflags) 292 { 293 int error; 294 int flags = 0; 295 296 if (mntflags & MNT_FORCE) 297 flags |= FORCECLOSE; 298 299 if ((error = vflush(mp, 0, flags)) != 0) 300 return (error); 301 302 /* Restore where pty access was pointing */ 303 (void)pty_sethandler(ptyfs_save_ptm); 304 ptyfs_save_ptm = NULL; 305 ptm_ptyfspty.arg = NULL; 306 307 /* 308 * Finally, throw away the ptyfsmount structure 309 */ 310 free(mp->mnt_data, M_PTYFSMNT); 311 mp->mnt_data = NULL; 312 ptyfs_count--; 313 314 return 0; 315 } 316 317 int 318 ptyfs_root(struct mount *mp, struct vnode **vpp) 319 { 320 /* setup "." */ 321 return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL); 322 } 323 324 /*ARGSUSED*/ 325 int 326 ptyfs_sync(struct mount *mp, int waitfor, 327 kauth_cred_t uc) 328 { 329 return 0; 330 } 331 332 /* 333 * Kernfs flat namespace lookup. 334 * Currently unsupported. 335 */ 336 /*ARGSUSED*/ 337 int 338 ptyfs_vget(struct mount *mp, ino_t ino, 339 struct vnode **vpp) 340 { 341 return EOPNOTSUPP; 342 } 343 344 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc; 345 346 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = { 347 &ptyfs_vnodeop_opv_desc, 348 NULL, 349 }; 350 351 struct vfsops ptyfs_vfsops = { 352 MOUNT_PTYFS, 353 sizeof (struct ptyfs_args), 354 ptyfs_mount, 355 ptyfs_start, 356 ptyfs_unmount, 357 ptyfs_root, 358 (void *)eopnotsupp, /* vfs_quotactl */ 359 genfs_statvfs, 360 ptyfs_sync, 361 ptyfs_vget, 362 (void *)eopnotsupp, /* vfs_fhtovp */ 363 (void *)eopnotsupp, /* vfs_vptofp */ 364 ptyfs_init, 365 ptyfs_reinit, 366 ptyfs_done, 367 NULL, /* vfs_mountroot */ 368 (void *)eopnotsupp, 369 (void *)eopnotsupp, 370 (void *)eopnotsupp, /* vfs_suspendctl */ 371 genfs_renamelock_enter, 372 genfs_renamelock_exit, 373 (void *)eopnotsupp, 374 ptyfs_vnodeopv_descs, 375 0, 376 { NULL, NULL }, 377 }; 378 379 static int 380 ptyfs_modcmd(modcmd_t cmd, void *arg) 381 { 382 int error; 383 384 switch (cmd) { 385 case MODULE_CMD_INIT: 386 error = vfs_attach(&ptyfs_vfsops); 387 if (error != 0) 388 break; 389 sysctl_createv(&ptyfs_sysctl_log, 0, NULL, NULL, 390 CTLFLAG_PERMANENT, 391 CTLTYPE_NODE, "vfs", NULL, 392 NULL, 0, NULL, 0, 393 CTL_VFS, CTL_EOL); 394 sysctl_createv(&ptyfs_sysctl_log, 0, NULL, NULL, 395 CTLFLAG_PERMANENT, 396 CTLTYPE_NODE, "ptyfs", 397 SYSCTL_DESCR("Pty file system"), 398 NULL, 0, NULL, 0, 399 CTL_VFS, 23, CTL_EOL); 400 /* 401 * XXX the "23" above could be dynamic, thereby eliminating 402 * one more instance of the "number to vfs" mapping problem, 403 * but "23" is the order as taken from sys/mount.h 404 */ 405 break; 406 case MODULE_CMD_FINI: 407 error = vfs_detach(&ptyfs_vfsops); 408 if (error != 0) 409 break; 410 sysctl_teardown(&ptyfs_sysctl_log); 411 break; 412 default: 413 error = ENOTTY; 414 break; 415 } 416 417 return (error); 418 } 419