| 1 | /* |
| 2 | * Copyright (c) 1990 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by the University of |
| 16 | * California, Berkeley and its contributors. |
| 17 | * 4. Neither the name of the University nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | * |
| 33 | * @(#)fifo_vnops.c 7.7 (Berkeley) 4/15/91 |
| 34 | */ |
| 35 | |
| 36 | #include "param.h" |
| 37 | #include "time.h" |
| 38 | #include "namei.h" |
| 39 | #include "vnode.h" |
| 40 | #include "socket.h" |
| 41 | #include "socketvar.h" |
| 42 | #include "stat.h" |
| 43 | #include "systm.h" |
| 44 | #include "ioctl.h" |
| 45 | #include "file.h" |
| 46 | #include "fifo.h" |
| 47 | #include "errno.h" |
| 48 | #include "malloc.h" |
| 49 | |
| 50 | /* |
| 51 | * This structure is associated with the FIFO vnode and stores |
| 52 | * the state associated with the FIFO. |
| 53 | */ |
| 54 | struct fifoinfo { |
| 55 | struct socket *fi_readsock; |
| 56 | struct socket *fi_writesock; |
| 57 | long fi_readers; |
| 58 | long fi_writers; |
| 59 | }; |
| 60 | |
| 61 | struct vnodeops fifo_vnodeops = { |
| 62 | fifo_lookup, /* lookup */ |
| 63 | fifo_create, /* create */ |
| 64 | fifo_mknod, /* mknod */ |
| 65 | fifo_open, /* open */ |
| 66 | fifo_close, /* close */ |
| 67 | fifo_access, /* access */ |
| 68 | fifo_getattr, /* getattr */ |
| 69 | fifo_setattr, /* setattr */ |
| 70 | fifo_read, /* read */ |
| 71 | fifo_write, /* write */ |
| 72 | fifo_ioctl, /* ioctl */ |
| 73 | fifo_select, /* select */ |
| 74 | fifo_mmap, /* mmap */ |
| 75 | fifo_fsync, /* fsync */ |
| 76 | fifo_seek, /* seek */ |
| 77 | fifo_remove, /* remove */ |
| 78 | fifo_link, /* link */ |
| 79 | fifo_rename, /* rename */ |
| 80 | fifo_mkdir, /* mkdir */ |
| 81 | fifo_rmdir, /* rmdir */ |
| 82 | fifo_symlink, /* symlink */ |
| 83 | fifo_readdir, /* readdir */ |
| 84 | fifo_readlink, /* readlink */ |
| 85 | fifo_abortop, /* abortop */ |
| 86 | fifo_inactive, /* inactive */ |
| 87 | fifo_reclaim, /* reclaim */ |
| 88 | fifo_lock, /* lock */ |
| 89 | fifo_unlock, /* unlock */ |
| 90 | fifo_bmap, /* bmap */ |
| 91 | fifo_strategy, /* strategy */ |
| 92 | fifo_print, /* print */ |
| 93 | fifo_islocked, /* islocked */ |
| 94 | fifo_advlock, /* advlock */ |
| 95 | }; |
| 96 | |
| 97 | /* |
| 98 | * Trivial lookup routine that always fails. |
| 99 | */ |
| 100 | /* ARGSUSED */ |
| 101 | fifo_lookup(vp, ndp, p) |
| 102 | struct vnode *vp; |
| 103 | struct nameidata *ndp; |
| 104 | struct proc *p; |
| 105 | { |
| 106 | |
| 107 | ndp->ni_dvp = vp; |
| 108 | ndp->ni_vp = NULL; |
| 109 | return (ENOTDIR); |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * Open called to set up a new instance of a fifo or |
| 114 | * to find an active instance of a fifo. |
| 115 | */ |
| 116 | /* ARGSUSED */ |
| 117 | fifo_open(vp, mode, cred, p) |
| 118 | register struct vnode *vp; |
| 119 | int mode; |
| 120 | struct ucred *cred; |
| 121 | struct proc *p; |
| 122 | { |
| 123 | register struct fifoinfo *fip; |
| 124 | struct socket *rso, *wso; |
| 125 | int error; |
| 126 | static char openstr[] = "fifo"; |
| 127 | |
| 128 | if ((mode & (FREAD|FWRITE)) == (FREAD|FWRITE)) |
| 129 | return (EINVAL); |
| 130 | if ((fip = vp->v_fifoinfo) == NULL) { |
| 131 | MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); |
| 132 | vp->v_fifoinfo = fip; |
| 133 | if (error = socreate(AF_UNIX, &rso, SOCK_STREAM, 0)) { |
| 134 | free(fip, M_VNODE); |
| 135 | vp->v_fifoinfo = NULL; |
| 136 | return (error); |
| 137 | } |
| 138 | fip->fi_readsock = rso; |
| 139 | if (error = socreate(AF_UNIX, &wso, SOCK_STREAM, 0)) { |
| 140 | (void)soclose(rso); |
| 141 | free(fip, M_VNODE); |
| 142 | vp->v_fifoinfo = NULL; |
| 143 | return (error); |
| 144 | } |
| 145 | fip->fi_writesock = wso; |
| 146 | if (error = unp_connect2(wso, rso)) { |
| 147 | (void)soclose(wso); |
| 148 | (void)soclose(rso); |
| 149 | free(fip, M_VNODE); |
| 150 | vp->v_fifoinfo = NULL; |
| 151 | return (error); |
| 152 | } |
| 153 | wso->so_state |= SS_CANTRCVMORE; |
| 154 | rso->so_state |= SS_CANTSENDMORE; |
| 155 | } |
| 156 | error = 0; |
| 157 | if (mode & FREAD) { |
| 158 | fip->fi_readers++; |
| 159 | if (fip->fi_readers == 1) { |
| 160 | fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; |
| 161 | if (fip->fi_writers > 0) |
| 162 | wakeup((caddr_t)&fip->fi_writers); |
| 163 | } |
| 164 | if (mode & O_NONBLOCK) |
| 165 | return (0); |
| 166 | while (fip->fi_writers == 0) |
| 167 | if (error = tsleep((caddr_t)&fip->fi_readers, PSOCK, |
| 168 | openstr, 0)) |
| 169 | break; |
| 170 | } else { |
| 171 | fip->fi_writers++; |
| 172 | if (fip->fi_readers == 0 && (mode & O_NONBLOCK)) { |
| 173 | error = ENXIO; |
| 174 | } else { |
| 175 | if (fip->fi_writers == 1) { |
| 176 | fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; |
| 177 | if (fip->fi_readers > 0) |
| 178 | wakeup((caddr_t)&fip->fi_readers); |
| 179 | } |
| 180 | while (fip->fi_readers == 0) |
| 181 | if (error = tsleep((caddr_t)&fip->fi_writers, |
| 182 | PSOCK, openstr, 0)) |
| 183 | break; |
| 184 | } |
| 185 | } |
| 186 | if (error) |
| 187 | fifo_close(vp, mode, cred, p); |
| 188 | return (error); |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Vnode op for read |
| 193 | */ |
| 194 | /* ARGSUSED */ |
| 195 | fifo_read(vp, uio, ioflag, cred) |
| 196 | struct vnode *vp; |
| 197 | register struct uio *uio; |
| 198 | int ioflag; |
| 199 | struct ucred *cred; |
| 200 | { |
| 201 | register struct socket *rso = vp->v_fifoinfo->fi_readsock; |
| 202 | int error, startresid; |
| 203 | |
| 204 | #ifdef DIAGNOSTIC |
| 205 | if (uio->uio_rw != UIO_READ) |
| 206 | panic("fifo_read mode"); |
| 207 | #endif |
| 208 | if (uio->uio_resid == 0) |
| 209 | return (0); |
| 210 | if (ioflag & IO_NDELAY) |
| 211 | rso->so_state |= SS_NBIO; |
| 212 | startresid = uio->uio_resid; |
| 213 | VOP_UNLOCK(vp); |
| 214 | error = soreceive(rso, (struct mbuf **)0, uio, (int *)0, |
| 215 | (struct mbuf **)0, (struct mbuf **)0); |
| 216 | VOP_LOCK(vp); |
| 217 | /* |
| 218 | * Clear EOF indication after first such return. |
| 219 | */ |
| 220 | if (uio->uio_resid == startresid) |
| 221 | rso->so_state &= ~SS_CANTRCVMORE; |
| 222 | if (ioflag & IO_NDELAY) |
| 223 | rso->so_state &= ~SS_NBIO; |
| 224 | return (error); |
| 225 | } |
| 226 | |
| 227 | /* |
| 228 | * Vnode op for write |
| 229 | */ |
| 230 | /* ARGSUSED */ |
| 231 | fifo_write(vp, uio, ioflag, cred) |
| 232 | struct vnode *vp; |
| 233 | register struct uio *uio; |
| 234 | int ioflag; |
| 235 | struct ucred *cred; |
| 236 | { |
| 237 | struct socket *wso = vp->v_fifoinfo->fi_writesock; |
| 238 | int error; |
| 239 | |
| 240 | #ifdef DIAGNOSTIC |
| 241 | if (uio->uio_rw != UIO_WRITE) |
| 242 | panic("fifo_write mode"); |
| 243 | #endif |
| 244 | if (ioflag & IO_NDELAY) |
| 245 | wso->so_state |= SS_NBIO; |
| 246 | VOP_UNLOCK(vp); |
| 247 | error = sosend(wso, (struct mbuf *)0, uio, 0, (struct mbuf *)0); |
| 248 | VOP_LOCK(vp); |
| 249 | if (ioflag & IO_NDELAY) |
| 250 | wso->so_state &= ~SS_NBIO; |
| 251 | return (error); |
| 252 | } |
| 253 | |
| 254 | /* |
| 255 | * Device ioctl operation. |
| 256 | */ |
| 257 | /* ARGSUSED */ |
| 258 | fifo_ioctl(vp, com, data, fflag, cred, p) |
| 259 | struct vnode *vp; |
| 260 | int com; |
| 261 | caddr_t data; |
| 262 | int fflag; |
| 263 | struct ucred *cred; |
| 264 | struct proc *p; |
| 265 | { |
| 266 | struct file filetmp; |
| 267 | int error; |
| 268 | |
| 269 | if (com == FIONBIO) |
| 270 | return (0); |
| 271 | if (fflag & FREAD) |
| 272 | filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock; |
| 273 | else |
| 274 | filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock; |
| 275 | return (soo_ioctl(&filetmp, com, data, p)); |
| 276 | } |
| 277 | |
| 278 | /* ARGSUSED */ |
| 279 | fifo_select(vp, which, fflag, cred, p) |
| 280 | struct vnode *vp; |
| 281 | int which, fflag; |
| 282 | struct ucred *cred; |
| 283 | struct proc *p; |
| 284 | { |
| 285 | struct file filetmp; |
| 286 | int error; |
| 287 | |
| 288 | if (fflag & FREAD) |
| 289 | filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock; |
| 290 | else |
| 291 | filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock; |
| 292 | return (soo_select(&filetmp, which, p)); |
| 293 | } |
| 294 | |
| 295 | /* |
| 296 | * This is a noop, simply returning what one has been given. |
| 297 | */ |
| 298 | fifo_bmap(vp, bn, vpp, bnp) |
| 299 | struct vnode *vp; |
| 300 | daddr_t bn; |
| 301 | struct vnode **vpp; |
| 302 | daddr_t *bnp; |
| 303 | { |
| 304 | |
| 305 | if (vpp != NULL) |
| 306 | *vpp = vp; |
| 307 | if (bnp != NULL) |
| 308 | *bnp = bn; |
| 309 | return (0); |
| 310 | } |
| 311 | |
| 312 | /* |
| 313 | * At the moment we do not do any locking. |
| 314 | */ |
| 315 | /* ARGSUSED */ |
| 316 | fifo_lock(vp) |
| 317 | struct vnode *vp; |
| 318 | { |
| 319 | |
| 320 | return (0); |
| 321 | } |
| 322 | |
| 323 | /* ARGSUSED */ |
| 324 | fifo_unlock(vp) |
| 325 | struct vnode *vp; |
| 326 | { |
| 327 | |
| 328 | return (0); |
| 329 | } |
| 330 | |
| 331 | /* |
| 332 | * Device close routine |
| 333 | */ |
| 334 | /* ARGSUSED */ |
| 335 | fifo_close(vp, fflag, cred, p) |
| 336 | register struct vnode *vp; |
| 337 | int fflag; |
| 338 | struct ucred *cred; |
| 339 | struct proc *p; |
| 340 | { |
| 341 | register struct fifoinfo *fip = vp->v_fifoinfo; |
| 342 | int error1, error2; |
| 343 | |
| 344 | if (fflag & FWRITE) { |
| 345 | fip->fi_writers--; |
| 346 | if (fip->fi_writers == 0) |
| 347 | socantrcvmore(fip->fi_readsock); |
| 348 | } else { |
| 349 | fip->fi_readers--; |
| 350 | if (fip->fi_readers == 0) |
| 351 | socantsendmore(fip->fi_writesock); |
| 352 | } |
| 353 | if (vp->v_usecount > 1) |
| 354 | return (0); |
| 355 | error1 = soclose(fip->fi_readsock); |
| 356 | error2 = soclose(fip->fi_writesock); |
| 357 | FREE(fip, M_VNODE); |
| 358 | vp->v_fifoinfo = NULL; |
| 359 | if (error1) |
| 360 | return (error1); |
| 361 | return (error2); |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | * Print out the contents of a fifo vnode. |
| 366 | */ |
| 367 | fifo_print(vp) |
| 368 | struct vnode *vp; |
| 369 | { |
| 370 | |
| 371 | printf("tag VT_NON"); |
| 372 | fifo_printinfo(vp); |
| 373 | printf("\n"); |
| 374 | } |
| 375 | |
| 376 | /* |
| 377 | * Print out internal contents of a fifo vnode. |
| 378 | */ |
| 379 | fifo_printinfo(vp) |
| 380 | struct vnode *vp; |
| 381 | { |
| 382 | register struct fifoinfo *fip = vp->v_fifoinfo; |
| 383 | |
| 384 | printf(", fifo with %d readers and %d writers", |
| 385 | fip->fi_readers, fip->fi_writers); |
| 386 | } |
| 387 | |
| 388 | /* |
| 389 | * Fifo failed operation |
| 390 | */ |
| 391 | fifo_ebadf() |
| 392 | { |
| 393 | |
| 394 | return (EBADF); |
| 395 | } |
| 396 | |
| 397 | /* |
| 398 | * Fifo advisory byte-level locks. |
| 399 | */ |
| 400 | /* ARGSUSED */ |
| 401 | fifo_advlock(vp, id, op, fl, flags) |
| 402 | struct vnode *vp; |
| 403 | caddr_t id; |
| 404 | int op; |
| 405 | struct flock *fl; |
| 406 | int flags; |
| 407 | { |
| 408 | |
| 409 | return (EOPNOTSUPP); |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * Fifo bad operation |
| 414 | */ |
| 415 | fifo_badop() |
| 416 | { |
| 417 | |
| 418 | panic("fifo_badop called"); |
| 419 | /* NOTREACHED */ |
| 420 | } |