1 /* $NetBSD: ptyfs_vfsops.c,v 1.12 2005/12/11 12:24:29 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 1.12 2005/12/11 12:24:29 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/tty.h> 57 #include <sys/pty.h> 58 59 #include <fs/ptyfs/ptyfs.h> 60 #include <miscfs/specfs/specdev.h> 61 62 MALLOC_DEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures"); 63 64 void ptyfs_init(void); 65 void ptyfs_reinit(void); 66 void ptyfs_done(void); 67 int ptyfs_mount(struct mount *, const char *, void *, struct nameidata *, 68 struct lwp *); 69 int ptyfs_start(struct mount *, int, struct lwp *); 70 int ptyfs_unmount(struct mount *, int, struct lwp *); 71 int ptyfs_statvfs(struct mount *, struct statvfs *, struct lwp *); 72 int ptyfs_quotactl(struct mount *, int, uid_t, void *, struct lwp *); 73 int ptyfs_sync(struct mount *, int, struct ucred *, struct lwp *); 74 int ptyfs_vget(struct mount *, ino_t, struct vnode **); 75 76 static int ptyfs__allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 77 dev_t, char); 78 static int ptyfs__makename(struct ptm_pty *, char *, size_t, dev_t, char); 79 static void ptyfs__getvattr(struct ptm_pty *, struct proc *, 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, char *tbuf, size_t bufsiz, dev_t dev, 96 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/%d", mp->mnt_stat.f_mntonname, 108 minor(dev)); 109 break; 110 default: 111 return EINVAL; 112 } 113 114 return len >= bufsiz ? ENOSPC : 0; 115 } 116 117 118 static int 119 /*ARGSUSED*/ 120 ptyfs__allocvp(struct ptm_pty *pt, struct lwp *l, struct vnode **vpp, 121 dev_t dev, char ms) 122 { 123 struct mount *mp = pt->arg; 124 ptyfstype type; 125 126 switch (ms) { 127 case 'p': 128 type = PTYFSptc; 129 break; 130 case 't': 131 type = PTYFSpts; 132 break; 133 default: 134 return EINVAL; 135 } 136 137 return ptyfs_allocvp(mp, vpp, type, minor(dev), l); 138 } 139 140 141 static void 142 ptyfs__getvattr(struct ptm_pty *pt, struct proc *p, struct vattr *vattr) 143 { 144 struct mount *mp = pt->arg; 145 struct ptyfsmount *pmnt = VFSTOPTY(mp); 146 VATTR_NULL(vattr); 147 /* get real uid */ 148 vattr->va_uid = p->p_cred->p_ruid; 149 vattr->va_gid = pmnt->pmnt_gid; 150 vattr->va_mode = pmnt->pmnt_mode; 151 } 152 153 154 void 155 ptyfs_init(void) 156 { 157 #ifdef _LKM 158 malloc_type_attach(M_PTYFSMNT); 159 #endif 160 ptyfs_hashinit(); 161 } 162 163 void 164 ptyfs_reinit(void) 165 { 166 ptyfs_hashreinit(); 167 } 168 169 void 170 ptyfs_done(void) 171 { 172 #ifdef _LKM 173 malloc_type_detach(M_PTYFSMNT); 174 #endif 175 ptyfs_hashdone(); 176 } 177 178 /* 179 * Mount the Pseudo tty params filesystem 180 */ 181 int 182 ptyfs_mount(struct mount *mp, const char *path, void *data, 183 struct nameidata *ndp, struct lwp *l) 184 { 185 int error = 0; 186 struct ptyfsmount *pmnt; 187 struct ptyfs_args args; 188 189 /* Don't allow more than one mount */ 190 if (ptyfs_count) 191 return EBUSY; 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 return copyout(&args, data, sizeof(args)); 206 } 207 208 if (mp->mnt_flag & MNT_UPDATE) 209 return EOPNOTSUPP; 210 211 if (data != NULL) { 212 error = copyin(data, &args, sizeof args); 213 if (error != 0) 214 return error; 215 216 if (args.version != PTYFS_ARGSVERSION) 217 return EINVAL; 218 } else { 219 /* 220 * Arguments are mandatory. 221 */ 222 return EINVAL; 223 } 224 225 pmnt = malloc(sizeof(struct ptyfsmount), M_UFSMNT, M_WAITOK); 226 227 mp->mnt_data = pmnt; 228 pmnt->pmnt_gid = args.gid; 229 pmnt->pmnt_mode = args.mode; 230 mp->mnt_flag |= MNT_LOCAL; 231 vfs_getnewfsid(mp); 232 233 if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs", 234 UIO_SYSSPACE, mp, l)) != 0) { 235 free(pmnt, M_UFSMNT); 236 return error; 237 } 238 239 /* Point pty access to us */ 240 241 ptm_ptyfspty.arg = mp; 242 ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty); 243 ptyfs_count++; 244 return 0; 245 } 246 247 /*ARGSUSED*/ 248 int 249 ptyfs_start(struct mount *mp, int flags, struct lwp *p) 250 { 251 return 0; 252 } 253 254 /*ARGSUSED*/ 255 int 256 ptyfs_unmount(struct mount *mp, int mntflags, struct lwp *p) 257 { 258 int error; 259 int flags = 0; 260 261 if (mntflags & MNT_FORCE) 262 flags |= FORCECLOSE; 263 264 if ((error = vflush(mp, 0, flags)) != 0) 265 return (error); 266 267 /* Restore where pty access was pointing */ 268 (void)pty_sethandler(ptyfs_save_ptm); 269 ptyfs_save_ptm = NULL; 270 ptm_ptyfspty.arg = NULL; 271 272 /* 273 * Finally, throw away the ptyfsmount structure 274 */ 275 free(mp->mnt_data, M_UFSMNT); 276 mp->mnt_data = 0; 277 ptyfs_count--; 278 279 return 0; 280 } 281 282 int 283 ptyfs_root(struct mount *mp, struct vnode **vpp) 284 { 285 /* setup "." */ 286 return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL); 287 } 288 289 /*ARGSUSED*/ 290 int 291 ptyfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, struct lwp *p) 292 { 293 return EOPNOTSUPP; 294 } 295 296 /*ARGSUSED*/ 297 int 298 ptyfs_statvfs(struct mount *mp, struct statvfs *sbp, struct lwp *p) 299 { 300 sbp->f_bsize = DEV_BSIZE; 301 sbp->f_frsize = DEV_BSIZE; 302 sbp->f_iosize = DEV_BSIZE; 303 sbp->f_blocks = 2; /* 1K to keep df happy */ 304 sbp->f_bfree = 0; 305 sbp->f_bavail = 0; 306 sbp->f_bresvd = 0; 307 sbp->f_files = 1024; /* XXX lie */ 308 sbp->f_ffree = 128; /* XXX lie */ 309 sbp->f_favail = 128; /* XXX lie */ 310 sbp->f_fresvd = 0; 311 sbp->f_namemax = MAXNAMLEN; 312 copy_statvfs_info(sbp, mp); 313 return 0; 314 } 315 316 /*ARGSUSED*/ 317 int 318 ptyfs_sync(struct mount *mp, int waitfor, struct ucred *uc, struct lwp *p) 319 { 320 return 0; 321 } 322 323 /* 324 * Kernfs flat namespace lookup. 325 * Currently unsupported. 326 */ 327 /*ARGSUSED*/ 328 int 329 ptyfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 330 { 331 return EOPNOTSUPP; 332 } 333 334 SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup") 335 { 336 337 sysctl_createv(clog, 0, NULL, NULL, 338 CTLFLAG_PERMANENT, 339 CTLTYPE_NODE, "vfs", NULL, 340 NULL, 0, NULL, 0, 341 CTL_VFS, CTL_EOL); 342 sysctl_createv(clog, 0, NULL, NULL, 343 CTLFLAG_PERMANENT, 344 CTLTYPE_NODE, "ptyfs", 345 SYSCTL_DESCR("Pty file system"), 346 NULL, 0, NULL, 0, 347 CTL_VFS, 23, CTL_EOL); 348 /* 349 * XXX the "23" above could be dynamic, thereby eliminating 350 * one more instance of the "number to vfs" mapping problem, 351 * but "23" is the order as taken from sys/mount.h 352 */ 353 } 354 355 356 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc; 357 358 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = { 359 &ptyfs_vnodeop_opv_desc, 360 NULL, 361 }; 362 363 struct vfsops ptyfs_vfsops = { 364 MOUNT_PTYFS, 365 ptyfs_mount, 366 ptyfs_start, 367 ptyfs_unmount, 368 ptyfs_root, 369 ptyfs_quotactl, 370 ptyfs_statvfs, 371 ptyfs_sync, 372 ptyfs_vget, 373 NULL, /* vfs_fhtovp */ 374 NULL, /* vfs_vptofp */ 375 ptyfs_init, 376 ptyfs_reinit, 377 ptyfs_done, 378 NULL, /* vfs_mountroot */ 379 (int (*)(struct mount *, struct vnode *, struct timespec *))eopnotsupp, 380 (int (*)(struct mount *, int, struct vnode *, int, const char *, 381 struct lwp *))eopnotsupp, 382 ptyfs_vnodeopv_descs, 383 }; 384 VFS_ATTACH(ptyfs_vfsops); 385