1 /* $NetBSD: ptyfs_vfsops.c,v 1.17 2006/06/20 09:17:14 tron 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 1.17 2006/06/20 09:17:14 tron 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 61 #include <fs/ptyfs/ptyfs.h> 62 #include <miscfs/specfs/specdev.h> 63 64 MALLOC_DEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures"); 65 66 void ptyfs_init(void); 67 void ptyfs_reinit(void); 68 void ptyfs_done(void); 69 int ptyfs_mount(struct mount *, const char *, void *, struct nameidata *, 70 struct lwp *); 71 int ptyfs_start(struct mount *, int, struct lwp *); 72 int ptyfs_unmount(struct mount *, int, struct lwp *); 73 int ptyfs_statvfs(struct mount *, struct statvfs *, struct lwp *); 74 int ptyfs_quotactl(struct mount *, int, uid_t, void *, struct lwp *); 75 int ptyfs_sync(struct mount *, int, kauth_cred_t, struct lwp *); 76 int ptyfs_vget(struct mount *, ino_t, struct vnode **); 77 78 static int ptyfs__allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 79 dev_t, char); 80 static int ptyfs__makename(struct ptm_pty *, struct lwp *, char *, size_t, 81 dev_t, char); 82 static void ptyfs__getvattr(struct ptm_pty *, struct proc *, struct vattr *); 83 84 /* 85 * ptm glue: When we mount, we make ptm point to us. 86 */ 87 struct ptm_pty *ptyfs_save_ptm; 88 static int ptyfs_count; 89 90 struct ptm_pty ptm_ptyfspty = { 91 ptyfs__allocvp, 92 ptyfs__makename, 93 ptyfs__getvattr, 94 NULL 95 }; 96 97 static const char * 98 ptyfs__getpath(struct lwp *l, const struct mount *mp) 99 { 100 #define MAXBUF (sizeof(mp->mnt_stat.f_mntonname) + 32) 101 struct cwdinfo *cwdi = l->l_proc->p_cwdi; 102 char *buf; 103 const char *rv; 104 size_t len; 105 char *bp; 106 int error; 107 108 rv = mp->mnt_stat.f_mntonname; 109 if (cwdi->cwdi_rdir == NULL) 110 return rv; 111 112 buf = malloc(MAXBUF, M_TEMP, M_WAITOK); 113 bp = buf + MAXBUF; 114 *--bp = '\0'; 115 error = getcwd_common(cwdi->cwdi_rdir, rootvnode, &bp, 116 buf, MAXBUF / 2, 0, l); 117 if (error) /* XXX */ 118 goto out; 119 120 len = strlen(bp); 121 if (len < sizeof(mp->mnt_stat.f_mntonname)) /* XXX */ 122 rv += len; 123 out: 124 free(buf, M_TEMP); 125 return rv; 126 } 127 128 static int 129 ptyfs__makename(struct ptm_pty *pt, struct lwp *l, char *tbuf, size_t bufsiz, 130 dev_t dev, char ms) 131 { 132 struct mount *mp = pt->arg; 133 size_t len; 134 135 switch (ms) { 136 case 'p': 137 /* We don't provide access to the master, should we? */ 138 len = snprintf(tbuf, bufsiz, "/dev/null"); 139 break; 140 case 't': 141 len = snprintf(tbuf, bufsiz, "%s/%d", ptyfs__getpath(l, mp), 142 minor(dev)); 143 break; 144 default: 145 return EINVAL; 146 } 147 148 return len >= bufsiz ? ENOSPC : 0; 149 } 150 151 152 static int 153 /*ARGSUSED*/ 154 ptyfs__allocvp(struct ptm_pty *pt, struct lwp *l, struct vnode **vpp, 155 dev_t dev, char ms) 156 { 157 struct mount *mp = pt->arg; 158 ptyfstype type; 159 160 switch (ms) { 161 case 'p': 162 type = PTYFSptc; 163 break; 164 case 't': 165 type = PTYFSpts; 166 break; 167 default: 168 return EINVAL; 169 } 170 171 return ptyfs_allocvp(mp, vpp, type, minor(dev), l); 172 } 173 174 175 static void 176 ptyfs__getvattr(struct ptm_pty *pt, struct proc *p, struct vattr *vattr) 177 { 178 struct mount *mp = pt->arg; 179 struct ptyfsmount *pmnt = VFSTOPTY(mp); 180 VATTR_NULL(vattr); 181 /* get real uid */ 182 vattr->va_uid = kauth_cred_getuid(p->p_cred); 183 vattr->va_gid = pmnt->pmnt_gid; 184 vattr->va_mode = pmnt->pmnt_mode; 185 } 186 187 188 void 189 ptyfs_init(void) 190 { 191 #ifdef _LKM 192 malloc_type_attach(M_PTYFSMNT); 193 #endif 194 ptyfs_hashinit(); 195 } 196 197 void 198 ptyfs_reinit(void) 199 { 200 ptyfs_hashreinit(); 201 } 202 203 void 204 ptyfs_done(void) 205 { 206 #ifdef _LKM 207 malloc_type_detach(M_PTYFSMNT); 208 #endif 209 ptyfs_hashdone(); 210 } 211 212 /* 213 * Mount the Pseudo tty params filesystem 214 */ 215 int 216 ptyfs_mount(struct mount *mp, const char *path, void *data, 217 struct nameidata *ndp, struct lwp *l) 218 { 219 int error = 0; 220 struct ptyfsmount *pmnt; 221 struct ptyfs_args args; 222 223 if (UIO_MX & (UIO_MX - 1)) { 224 log(LOG_ERR, "ptyfs: invalid directory entry size"); 225 return EINVAL; 226 } 227 228 if (mp->mnt_flag & MNT_GETARGS) { 229 pmnt = VFSTOPTY(mp); 230 if (pmnt == NULL) 231 return EIO; 232 args.version = PTYFS_ARGSVERSION; 233 args.mode = pmnt->pmnt_mode; 234 args.gid = pmnt->pmnt_gid; 235 return copyout(&args, data, sizeof(args)); 236 } 237 238 /* Don't allow more than one mount */ 239 if (ptyfs_count) 240 return EBUSY; 241 242 if (mp->mnt_flag & MNT_UPDATE) 243 return EOPNOTSUPP; 244 245 if (data != NULL) { 246 error = copyin(data, &args, sizeof args); 247 if (error != 0) 248 return error; 249 250 if (args.version != PTYFS_ARGSVERSION) 251 return EINVAL; 252 } else { 253 /* 254 * Arguments are mandatory. 255 */ 256 return EINVAL; 257 } 258 259 pmnt = malloc(sizeof(struct ptyfsmount), M_UFSMNT, M_WAITOK); 260 261 mp->mnt_data = pmnt; 262 pmnt->pmnt_gid = args.gid; 263 pmnt->pmnt_mode = args.mode; 264 mp->mnt_flag |= MNT_LOCAL; 265 vfs_getnewfsid(mp); 266 267 if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs", 268 UIO_SYSSPACE, mp, l)) != 0) { 269 free(pmnt, M_UFSMNT); 270 return error; 271 } 272 273 /* Point pty access to us */ 274 275 ptm_ptyfspty.arg = mp; 276 ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty); 277 ptyfs_count++; 278 return 0; 279 } 280 281 /*ARGSUSED*/ 282 int 283 ptyfs_start(struct mount *mp, int flags, struct lwp *p) 284 { 285 return 0; 286 } 287 288 /*ARGSUSED*/ 289 int 290 ptyfs_unmount(struct mount *mp, int mntflags, struct lwp *p) 291 { 292 int error; 293 int flags = 0; 294 295 if (mntflags & MNT_FORCE) 296 flags |= FORCECLOSE; 297 298 if ((error = vflush(mp, 0, flags)) != 0) 299 return (error); 300 301 /* Restore where pty access was pointing */ 302 (void)pty_sethandler(ptyfs_save_ptm); 303 ptyfs_save_ptm = NULL; 304 ptm_ptyfspty.arg = NULL; 305 306 /* 307 * Finally, throw away the ptyfsmount structure 308 */ 309 free(mp->mnt_data, M_UFSMNT); 310 mp->mnt_data = 0; 311 ptyfs_count--; 312 313 return 0; 314 } 315 316 int 317 ptyfs_root(struct mount *mp, struct vnode **vpp) 318 { 319 /* setup "." */ 320 return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL); 321 } 322 323 /*ARGSUSED*/ 324 int 325 ptyfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, struct lwp *p) 326 { 327 return EOPNOTSUPP; 328 } 329 330 /*ARGSUSED*/ 331 int 332 ptyfs_statvfs(struct mount *mp, struct statvfs *sbp, struct lwp *p) 333 { 334 sbp->f_bsize = DEV_BSIZE; 335 sbp->f_frsize = DEV_BSIZE; 336 sbp->f_iosize = DEV_BSIZE; 337 sbp->f_blocks = 2; /* 1K to keep df happy */ 338 sbp->f_bfree = 0; 339 sbp->f_bavail = 0; 340 sbp->f_bresvd = 0; 341 sbp->f_files = 1024; /* XXX lie */ 342 sbp->f_ffree = 128; /* XXX lie */ 343 sbp->f_favail = 128; /* XXX lie */ 344 sbp->f_fresvd = 0; 345 sbp->f_namemax = MAXNAMLEN; 346 copy_statvfs_info(sbp, mp); 347 return 0; 348 } 349 350 /*ARGSUSED*/ 351 int 352 ptyfs_sync(struct mount *mp, int waitfor, kauth_cred_t uc, struct lwp *p) 353 { 354 return 0; 355 } 356 357 /* 358 * Kernfs flat namespace lookup. 359 * Currently unsupported. 360 */ 361 /*ARGSUSED*/ 362 int 363 ptyfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 364 { 365 return EOPNOTSUPP; 366 } 367 368 SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup") 369 { 370 371 sysctl_createv(clog, 0, NULL, NULL, 372 CTLFLAG_PERMANENT, 373 CTLTYPE_NODE, "vfs", NULL, 374 NULL, 0, NULL, 0, 375 CTL_VFS, CTL_EOL); 376 sysctl_createv(clog, 0, NULL, NULL, 377 CTLFLAG_PERMANENT, 378 CTLTYPE_NODE, "ptyfs", 379 SYSCTL_DESCR("Pty file system"), 380 NULL, 0, NULL, 0, 381 CTL_VFS, 23, CTL_EOL); 382 /* 383 * XXX the "23" above could be dynamic, thereby eliminating 384 * one more instance of the "number to vfs" mapping problem, 385 * but "23" is the order as taken from sys/mount.h 386 */ 387 } 388 389 390 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc; 391 392 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = { 393 &ptyfs_vnodeop_opv_desc, 394 NULL, 395 }; 396 397 struct vfsops ptyfs_vfsops = { 398 MOUNT_PTYFS, 399 ptyfs_mount, 400 ptyfs_start, 401 ptyfs_unmount, 402 ptyfs_root, 403 ptyfs_quotactl, 404 ptyfs_statvfs, 405 ptyfs_sync, 406 ptyfs_vget, 407 NULL, /* vfs_fhtovp */ 408 NULL, /* vfs_vptofp */ 409 ptyfs_init, 410 ptyfs_reinit, 411 ptyfs_done, 412 NULL, /* vfs_mountroot */ 413 (int (*)(struct mount *, struct vnode *, struct timespec *))eopnotsupp, 414 (int (*)(struct mount *, int, struct vnode *, int, const char *, 415 struct lwp *))eopnotsupp, 416 ptyfs_vnodeopv_descs, 417 }; 418 VFS_ATTACH(ptyfs_vfsops); 419