1 /* $NetBSD: ptyfs_vfsops.c,v 1.32 2008/04/29 18:18:08 ad 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 1.32 2008/04/29 18:18:08 ad 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/genfs/genfs.h> 63 #include <miscfs/specfs/specdev.h> 64 65 MALLOC_JUSTDEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures"); 66 MALLOC_JUSTDEFINE(M_PTYFSTMP, "ptyfs temp", "ptyfs temporary structures"); 67 68 VFS_PROTOS(ptyfs); 69 70 static int ptyfs__allocvp(struct ptm_pty *, struct lwp *, struct vnode **, 71 dev_t, char); 72 static int ptyfs__makename(struct ptm_pty *, struct lwp *, char *, size_t, 73 dev_t, char); 74 static void ptyfs__getvattr(struct ptm_pty *, struct lwp *, struct vattr *); 75 76 /* 77 * ptm glue: When we mount, we make ptm point to us. 78 */ 79 struct ptm_pty *ptyfs_save_ptm; 80 static int ptyfs_count; 81 82 struct ptm_pty ptm_ptyfspty = { 83 ptyfs__allocvp, 84 ptyfs__makename, 85 ptyfs__getvattr, 86 NULL 87 }; 88 89 static const char * 90 ptyfs__getpath(struct lwp *l, const struct mount *mp) 91 { 92 #define MAXBUF (sizeof(mp->mnt_stat.f_mntonname) + 32) 93 struct cwdinfo *cwdi = l->l_proc->p_cwdi; 94 char *buf; 95 const char *rv; 96 size_t len; 97 char *bp; 98 int error; 99 100 rv = mp->mnt_stat.f_mntonname; 101 if (cwdi->cwdi_rdir == NULL) 102 return rv; 103 104 buf = malloc(MAXBUF, M_TEMP, M_WAITOK); 105 bp = buf + MAXBUF; 106 *--bp = '\0'; 107 error = getcwd_common(cwdi->cwdi_rdir, rootvnode, &bp, 108 buf, MAXBUF / 2, 0, l); 109 if (error) /* XXX */ 110 goto out; 111 112 len = strlen(bp); 113 if (len < sizeof(mp->mnt_stat.f_mntonname)) /* XXX */ 114 rv += len; 115 out: 116 free(buf, M_TEMP); 117 return rv; 118 } 119 120 static int 121 ptyfs__makename(struct ptm_pty *pt, struct lwp *l, char *tbuf, size_t bufsiz, 122 dev_t dev, char ms) 123 { 124 struct mount *mp = pt->arg; 125 size_t len; 126 127 switch (ms) { 128 case 'p': 129 /* We don't provide access to the master, should we? */ 130 len = snprintf(tbuf, bufsiz, "/dev/null"); 131 break; 132 case 't': 133 len = snprintf(tbuf, bufsiz, "%s/%d", ptyfs__getpath(l, mp), 134 minor(dev)); 135 break; 136 default: 137 return EINVAL; 138 } 139 140 return len >= bufsiz ? ENOSPC : 0; 141 } 142 143 144 static int 145 /*ARGSUSED*/ 146 ptyfs__allocvp(struct ptm_pty *pt, struct lwp *l, struct vnode **vpp, 147 dev_t dev, char ms) 148 { 149 struct mount *mp = pt->arg; 150 ptyfstype type; 151 152 switch (ms) { 153 case 'p': 154 type = PTYFSptc; 155 break; 156 case 't': 157 type = PTYFSpts; 158 break; 159 default: 160 return EINVAL; 161 } 162 163 return ptyfs_allocvp(mp, vpp, type, minor(dev), l); 164 } 165 166 167 static void 168 ptyfs__getvattr(struct ptm_pty *pt, struct lwp *l, struct vattr *vattr) 169 { 170 struct mount *mp = pt->arg; 171 struct ptyfsmount *pmnt = VFSTOPTY(mp); 172 VATTR_NULL(vattr); 173 /* get real uid */ 174 vattr->va_uid = kauth_cred_getuid(l->l_cred); 175 vattr->va_gid = pmnt->pmnt_gid; 176 vattr->va_mode = pmnt->pmnt_mode; 177 } 178 179 180 void 181 ptyfs_init(void) 182 { 183 184 malloc_type_attach(M_PTYFSMNT); 185 malloc_type_attach(M_PTYFSTMP); 186 ptyfs_hashinit(); 187 } 188 189 void 190 ptyfs_reinit(void) 191 { 192 ptyfs_hashreinit(); 193 } 194 195 void 196 ptyfs_done(void) 197 { 198 199 ptyfs_hashdone(); 200 malloc_type_detach(M_PTYFSTMP); 201 malloc_type_detach(M_PTYFSMNT); 202 } 203 204 /* 205 * Mount the Pseudo tty params filesystem 206 */ 207 int 208 ptyfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 209 { 210 struct lwp *l = curlwp; 211 int error = 0; 212 struct ptyfsmount *pmnt; 213 struct ptyfs_args *args = data; 214 215 if (*data_len < sizeof *args) 216 return EINVAL; 217 218 if (UIO_MX & (UIO_MX - 1)) { 219 log(LOG_ERR, "ptyfs: invalid directory entry size"); 220 return EINVAL; 221 } 222 223 if (mp->mnt_flag & MNT_GETARGS) { 224 pmnt = VFSTOPTY(mp); 225 if (pmnt == NULL) 226 return EIO; 227 args->version = PTYFS_ARGSVERSION; 228 args->mode = pmnt->pmnt_mode; 229 args->gid = pmnt->pmnt_gid; 230 *data_len = sizeof *args; 231 return 0; 232 } 233 234 /* Don't allow more than one mount */ 235 if (ptyfs_count) 236 return EBUSY; 237 238 if (mp->mnt_flag & MNT_UPDATE) 239 return EOPNOTSUPP; 240 241 if (args->version != PTYFS_ARGSVERSION) 242 return EINVAL; 243 244 pmnt = malloc(sizeof(struct ptyfsmount), M_PTYFSMNT, M_WAITOK); 245 246 mp->mnt_data = pmnt; 247 pmnt->pmnt_gid = args->gid; 248 pmnt->pmnt_mode = args->mode; 249 mp->mnt_flag |= MNT_LOCAL; 250 vfs_getnewfsid(mp); 251 252 if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs", 253 UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) { 254 free(pmnt, M_UFSMNT); 255 return error; 256 } 257 258 /* Point pty access to us */ 259 260 ptm_ptyfspty.arg = mp; 261 ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty); 262 ptyfs_count++; 263 return 0; 264 } 265 266 /*ARGSUSED*/ 267 int 268 ptyfs_start(struct mount *mp, int flags) 269 { 270 return 0; 271 } 272 273 /*ARGSUSED*/ 274 int 275 ptyfs_unmount(struct mount *mp, int mntflags) 276 { 277 int error; 278 int flags = 0; 279 280 if (mntflags & MNT_FORCE) 281 flags |= FORCECLOSE; 282 283 if ((error = vflush(mp, 0, flags)) != 0) 284 return (error); 285 286 /* Restore where pty access was pointing */ 287 (void)pty_sethandler(ptyfs_save_ptm); 288 ptyfs_save_ptm = NULL; 289 ptm_ptyfspty.arg = NULL; 290 291 /* 292 * Finally, throw away the ptyfsmount structure 293 */ 294 free(mp->mnt_data, M_UFSMNT); 295 mp->mnt_data = 0; 296 ptyfs_count--; 297 298 return 0; 299 } 300 301 int 302 ptyfs_root(struct mount *mp, struct vnode **vpp) 303 { 304 /* setup "." */ 305 return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL); 306 } 307 308 /*ARGSUSED*/ 309 int 310 ptyfs_statvfs(struct mount *mp, struct statvfs *sbp) 311 { 312 sbp->f_bsize = DEV_BSIZE; 313 sbp->f_frsize = DEV_BSIZE; 314 sbp->f_iosize = DEV_BSIZE; 315 sbp->f_blocks = 2; /* 1K to keep df happy */ 316 sbp->f_bfree = 0; 317 sbp->f_bavail = 0; 318 sbp->f_bresvd = 0; 319 sbp->f_files = 1024; /* XXX lie */ 320 sbp->f_ffree = 128; /* XXX lie */ 321 sbp->f_favail = 128; /* XXX lie */ 322 sbp->f_fresvd = 0; 323 sbp->f_namemax = MAXNAMLEN; 324 copy_statvfs_info(sbp, mp); 325 return 0; 326 } 327 328 /*ARGSUSED*/ 329 int 330 ptyfs_sync(struct mount *mp, int waitfor, 331 kauth_cred_t uc) 332 { 333 return 0; 334 } 335 336 /* 337 * Kernfs flat namespace lookup. 338 * Currently unsupported. 339 */ 340 /*ARGSUSED*/ 341 int 342 ptyfs_vget(struct mount *mp, ino_t ino, 343 struct vnode **vpp) 344 { 345 return EOPNOTSUPP; 346 } 347 348 SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup") 349 { 350 351 sysctl_createv(clog, 0, NULL, NULL, 352 CTLFLAG_PERMANENT, 353 CTLTYPE_NODE, "vfs", NULL, 354 NULL, 0, NULL, 0, 355 CTL_VFS, CTL_EOL); 356 sysctl_createv(clog, 0, NULL, NULL, 357 CTLFLAG_PERMANENT, 358 CTLTYPE_NODE, "ptyfs", 359 SYSCTL_DESCR("Pty file system"), 360 NULL, 0, NULL, 0, 361 CTL_VFS, 23, CTL_EOL); 362 /* 363 * XXX the "23" above could be dynamic, thereby eliminating 364 * one more instance of the "number to vfs" mapping problem, 365 * but "23" is the order as taken from sys/mount.h 366 */ 367 } 368 369 370 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc; 371 372 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = { 373 &ptyfs_vnodeop_opv_desc, 374 NULL, 375 }; 376 377 struct vfsops ptyfs_vfsops = { 378 MOUNT_PTYFS, 379 sizeof (struct ptyfs_args), 380 ptyfs_mount, 381 ptyfs_start, 382 ptyfs_unmount, 383 ptyfs_root, 384 (void *)eopnotsupp, /* vfs_quotactl */ 385 ptyfs_statvfs, 386 ptyfs_sync, 387 ptyfs_vget, 388 (void *)eopnotsupp, /* vfs_fhtovp */ 389 (void *)eopnotsupp, /* vfs_vptofp */ 390 ptyfs_init, 391 ptyfs_reinit, 392 ptyfs_done, 393 NULL, /* vfs_mountroot */ 394 (void *)eopnotsupp, 395 (void *)eopnotsupp, 396 (void *)eopnotsupp, /* vfs_suspendctl */ 397 genfs_renamelock_enter, 398 genfs_renamelock_exit, 399 (void *)eopnotsupp, 400 ptyfs_vnodeopv_descs, 401 0, 402 { NULL, NULL }, 403 }; 404 VFS_ATTACH(ptyfs_vfsops); 405