1 /* 2 * Copyright (c) 1990, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)fifo_vnops.c 8.8 (Berkeley) 05/14/95 8 */ 9 10 #include <sys/param.h> 11 #include <sys/systm.h> 12 #include <sys/proc.h> 13 #include <sys/time.h> 14 #include <sys/namei.h> 15 #include <sys/vnode.h> 16 #include <sys/socket.h> 17 #include <sys/socketvar.h> 18 #include <sys/stat.h> 19 #include <sys/ioctl.h> 20 #include <sys/file.h> 21 #include <sys/errno.h> 22 #include <sys/malloc.h> 23 #include <miscfs/fifofs/fifo.h> 24 25 /* 26 * This structure is associated with the FIFO vnode and stores 27 * the state associated with the FIFO. 28 */ 29 struct fifoinfo { 30 struct socket *fi_readsock; 31 struct socket *fi_writesock; 32 long fi_readers; 33 long fi_writers; 34 }; 35 36 int (**fifo_vnodeop_p)(); 37 struct vnodeopv_entry_desc fifo_vnodeop_entries[] = { 38 { &vop_default_desc, vn_default_error }, 39 { &vop_lookup_desc, fifo_lookup }, /* lookup */ 40 { &vop_create_desc, fifo_create }, /* create */ 41 { &vop_mknod_desc, fifo_mknod }, /* mknod */ 42 { &vop_open_desc, fifo_open }, /* open */ 43 { &vop_close_desc, fifo_close }, /* close */ 44 { &vop_access_desc, fifo_access }, /* access */ 45 { &vop_getattr_desc, fifo_getattr }, /* getattr */ 46 { &vop_setattr_desc, fifo_setattr }, /* setattr */ 47 { &vop_read_desc, fifo_read }, /* read */ 48 { &vop_write_desc, fifo_write }, /* write */ 49 { &vop_lease_desc, fifo_lease_check }, /* lease */ 50 { &vop_ioctl_desc, fifo_ioctl }, /* ioctl */ 51 { &vop_select_desc, fifo_select }, /* select */ 52 { &vop_revoke_desc, fifo_revoke }, /* revoke */ 53 { &vop_mmap_desc, fifo_mmap }, /* mmap */ 54 { &vop_fsync_desc, fifo_fsync }, /* fsync */ 55 { &vop_seek_desc, fifo_seek }, /* seek */ 56 { &vop_remove_desc, fifo_remove }, /* remove */ 57 { &vop_link_desc, fifo_link }, /* link */ 58 { &vop_rename_desc, fifo_rename }, /* rename */ 59 { &vop_mkdir_desc, fifo_mkdir }, /* mkdir */ 60 { &vop_rmdir_desc, fifo_rmdir }, /* rmdir */ 61 { &vop_symlink_desc, fifo_symlink }, /* symlink */ 62 { &vop_readdir_desc, fifo_readdir }, /* readdir */ 63 { &vop_readlink_desc, fifo_readlink }, /* readlink */ 64 { &vop_abortop_desc, fifo_abortop }, /* abortop */ 65 { &vop_inactive_desc, fifo_inactive }, /* inactive */ 66 { &vop_reclaim_desc, fifo_reclaim }, /* reclaim */ 67 { &vop_lock_desc, fifo_lock }, /* lock */ 68 { &vop_unlock_desc, fifo_unlock }, /* unlock */ 69 { &vop_bmap_desc, fifo_bmap }, /* bmap */ 70 { &vop_strategy_desc, fifo_strategy }, /* strategy */ 71 { &vop_print_desc, fifo_print }, /* print */ 72 { &vop_islocked_desc, fifo_islocked }, /* islocked */ 73 { &vop_pathconf_desc, fifo_pathconf }, /* pathconf */ 74 { &vop_advlock_desc, fifo_advlock }, /* advlock */ 75 { &vop_blkatoff_desc, fifo_blkatoff }, /* blkatoff */ 76 { &vop_valloc_desc, fifo_valloc }, /* valloc */ 77 { &vop_vfree_desc, fifo_vfree }, /* vfree */ 78 { &vop_truncate_desc, fifo_truncate }, /* truncate */ 79 { &vop_update_desc, fifo_update }, /* update */ 80 { &vop_bwrite_desc, fifo_bwrite }, /* bwrite */ 81 { (struct vnodeop_desc*)NULL, (int(*)())NULL } 82 }; 83 struct vnodeopv_desc fifo_vnodeop_opv_desc = 84 { &fifo_vnodeop_p, fifo_vnodeop_entries }; 85 86 /* 87 * Trivial lookup routine that always fails. 88 */ 89 /* ARGSUSED */ 90 fifo_lookup(ap) 91 struct vop_lookup_args /* { 92 struct vnode * a_dvp; 93 struct vnode ** a_vpp; 94 struct componentname * a_cnp; 95 } */ *ap; 96 { 97 98 *ap->a_vpp = NULL; 99 return (ENOTDIR); 100 } 101 102 /* 103 * Open called to set up a new instance of a fifo or 104 * to find an active instance of a fifo. 105 */ 106 /* ARGSUSED */ 107 fifo_open(ap) 108 struct vop_open_args /* { 109 struct vnode *a_vp; 110 int a_mode; 111 struct ucred *a_cred; 112 struct proc *a_p; 113 } */ *ap; 114 { 115 struct vnode *vp = ap->a_vp; 116 struct fifoinfo *fip; 117 struct proc *p = ap->a_p; 118 struct socket *rso, *wso; 119 int error; 120 static char openstr[] = "fifo"; 121 122 if ((ap->a_mode & (FREAD|FWRITE)) == (FREAD|FWRITE)) 123 return (EINVAL); 124 if ((fip = vp->v_fifoinfo) == NULL) { 125 MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK); 126 vp->v_fifoinfo = fip; 127 if (error = socreate(AF_LOCAL, &rso, SOCK_STREAM, 0)) { 128 free(fip, M_VNODE); 129 vp->v_fifoinfo = NULL; 130 return (error); 131 } 132 fip->fi_readsock = rso; 133 if (error = socreate(AF_LOCAL, &wso, SOCK_STREAM, 0)) { 134 (void)soclose(rso); 135 free(fip, M_VNODE); 136 vp->v_fifoinfo = NULL; 137 return (error); 138 } 139 fip->fi_writesock = wso; 140 if (error = unp_connect2(wso, rso)) { 141 (void)soclose(wso); 142 (void)soclose(rso); 143 free(fip, M_VNODE); 144 vp->v_fifoinfo = NULL; 145 return (error); 146 } 147 fip->fi_readers = fip->fi_writers = 0; 148 wso->so_state |= SS_CANTRCVMORE; 149 rso->so_state |= SS_CANTSENDMORE; 150 } 151 error = 0; 152 if (ap->a_mode & FREAD) { 153 fip->fi_readers++; 154 if (fip->fi_readers == 1) { 155 fip->fi_writesock->so_state &= ~SS_CANTSENDMORE; 156 if (fip->fi_writers > 0) 157 wakeup((caddr_t)&fip->fi_writers); 158 } 159 if (ap->a_mode & O_NONBLOCK) 160 return (0); 161 while (fip->fi_writers == 0) { 162 VOP_UNLOCK(vp, 0, p); 163 error = tsleep((caddr_t)&fip->fi_readers, 164 PCATCH | PSOCK, openstr, 0); 165 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 166 if (error) 167 break; 168 } 169 } else { 170 fip->fi_writers++; 171 if (fip->fi_readers == 0 && (ap->a_mode & O_NONBLOCK)) { 172 error = ENXIO; 173 } else { 174 if (fip->fi_writers == 1) { 175 fip->fi_readsock->so_state &= ~SS_CANTRCVMORE; 176 if (fip->fi_readers > 0) 177 wakeup((caddr_t)&fip->fi_readers); 178 } 179 while (fip->fi_readers == 0) { 180 VOP_UNLOCK(vp, 0, p); 181 error = tsleep((caddr_t)&fip->fi_writers, 182 PCATCH | PSOCK, openstr, 0); 183 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 184 if (error) 185 break; 186 } 187 } 188 } 189 if (error) 190 VOP_CLOSE(vp, ap->a_mode, ap->a_cred, p); 191 return (error); 192 } 193 194 /* 195 * Vnode op for read 196 */ 197 /* ARGSUSED */ 198 fifo_read(ap) 199 struct vop_read_args /* { 200 struct vnode *a_vp; 201 struct uio *a_uio; 202 int a_ioflag; 203 struct ucred *a_cred; 204 } */ *ap; 205 { 206 struct uio *uio = ap->a_uio; 207 struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock; 208 struct proc *p = uio->uio_procp; 209 int error, startresid; 210 211 #ifdef DIAGNOSTIC 212 if (uio->uio_rw != UIO_READ) 213 panic("fifo_read mode"); 214 #endif 215 if (uio->uio_resid == 0) 216 return (0); 217 if (ap->a_ioflag & IO_NDELAY) 218 rso->so_state |= SS_NBIO; 219 startresid = uio->uio_resid; 220 VOP_UNLOCK(ap->a_vp, 0, p); 221 error = soreceive(rso, (struct mbuf **)0, uio, (struct mbuf **)0, 222 (struct mbuf **)0, (int *)0); 223 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p); 224 /* 225 * Clear EOF indication after first such return. 226 */ 227 if (uio->uio_resid == startresid) 228 rso->so_state &= ~SS_CANTRCVMORE; 229 if (ap->a_ioflag & IO_NDELAY) 230 rso->so_state &= ~SS_NBIO; 231 return (error); 232 } 233 234 /* 235 * Vnode op for write 236 */ 237 /* ARGSUSED */ 238 fifo_write(ap) 239 struct vop_write_args /* { 240 struct vnode *a_vp; 241 struct uio *a_uio; 242 int a_ioflag; 243 struct ucred *a_cred; 244 } */ *ap; 245 { 246 struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock; 247 struct proc *p = ap->a_uio->uio_procp; 248 int error; 249 250 #ifdef DIAGNOSTIC 251 if (ap->a_uio->uio_rw != UIO_WRITE) 252 panic("fifo_write mode"); 253 #endif 254 if (ap->a_ioflag & IO_NDELAY) 255 wso->so_state |= SS_NBIO; 256 VOP_UNLOCK(ap->a_vp, 0, p); 257 error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0); 258 vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY, p); 259 if (ap->a_ioflag & IO_NDELAY) 260 wso->so_state &= ~SS_NBIO; 261 return (error); 262 } 263 264 /* 265 * Device ioctl operation. 266 */ 267 /* ARGSUSED */ 268 fifo_ioctl(ap) 269 struct vop_ioctl_args /* { 270 struct vnode *a_vp; 271 int a_command; 272 caddr_t a_data; 273 int a_fflag; 274 struct ucred *a_cred; 275 struct proc *a_p; 276 } */ *ap; 277 { 278 struct file filetmp; 279 280 if (ap->a_command == FIONBIO) 281 return (0); 282 if (ap->a_fflag & FREAD) 283 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 284 else 285 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 286 return (soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p)); 287 } 288 289 /* ARGSUSED */ 290 fifo_select(ap) 291 struct vop_select_args /* { 292 struct vnode *a_vp; 293 int a_which; 294 int a_fflags; 295 struct ucred *a_cred; 296 struct proc *a_p; 297 } */ *ap; 298 { 299 struct file filetmp; 300 301 if (ap->a_fflags & FREAD) 302 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock; 303 else 304 filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock; 305 return (soo_select(&filetmp, ap->a_which, ap->a_p)); 306 } 307 308 /* 309 * This is a noop, simply returning what one has been given. 310 */ 311 fifo_bmap(ap) 312 struct vop_bmap_args /* { 313 struct vnode *a_vp; 314 daddr_t a_bn; 315 struct vnode **a_vpp; 316 daddr_t *a_bnp; 317 int *a_runp; 318 } */ *ap; 319 { 320 321 if (ap->a_vpp != NULL) 322 *ap->a_vpp = ap->a_vp; 323 if (ap->a_bnp != NULL) 324 *ap->a_bnp = ap->a_bn; 325 if (ap->a_runp != NULL) 326 *ap->a_runp = 0; 327 return (0); 328 } 329 330 /* 331 * Device close routine 332 */ 333 /* ARGSUSED */ 334 fifo_close(ap) 335 struct vop_close_args /* { 336 struct vnode *a_vp; 337 int a_fflag; 338 struct ucred *a_cred; 339 struct proc *a_p; 340 } */ *ap; 341 { 342 register struct vnode *vp = ap->a_vp; 343 register struct fifoinfo *fip = vp->v_fifoinfo; 344 int error1, error2; 345 346 if (ap->a_fflag & FWRITE) { 347 fip->fi_writers--; 348 if (fip->fi_writers == 0) 349 socantrcvmore(fip->fi_readsock); 350 } else { 351 fip->fi_readers--; 352 if (fip->fi_readers == 0) 353 socantsendmore(fip->fi_writesock); 354 } 355 if (vp->v_usecount > 1) 356 return (0); 357 error1 = soclose(fip->fi_readsock); 358 error2 = soclose(fip->fi_writesock); 359 FREE(fip, M_VNODE); 360 vp->v_fifoinfo = NULL; 361 if (error1) 362 return (error1); 363 return (error2); 364 } 365 366 /* 367 * Print out the contents of a fifo vnode. 368 */ 369 fifo_print(ap) 370 struct vop_print_args /* { 371 struct vnode *a_vp; 372 } */ *ap; 373 { 374 375 printf("tag VT_NON"); 376 fifo_printinfo(ap->a_vp); 377 printf("\n"); 378 } 379 380 /* 381 * Print out internal contents of a fifo vnode. 382 */ 383 fifo_printinfo(vp) 384 struct vnode *vp; 385 { 386 register struct fifoinfo *fip = vp->v_fifoinfo; 387 388 printf(", fifo with %d readers and %d writers", 389 fip->fi_readers, fip->fi_writers); 390 } 391 392 /* 393 * Return POSIX pathconf information applicable to fifo's. 394 */ 395 fifo_pathconf(ap) 396 struct vop_pathconf_args /* { 397 struct vnode *a_vp; 398 int a_name; 399 int *a_retval; 400 } */ *ap; 401 { 402 403 switch (ap->a_name) { 404 case _PC_LINK_MAX: 405 *ap->a_retval = LINK_MAX; 406 return (0); 407 case _PC_PIPE_BUF: 408 *ap->a_retval = PIPE_BUF; 409 return (0); 410 case _PC_CHOWN_RESTRICTED: 411 *ap->a_retval = 1; 412 return (0); 413 default: 414 return (EINVAL); 415 } 416 /* NOTREACHED */ 417 } 418 419 /* 420 * Fifo failed operation 421 */ 422 fifo_ebadf() 423 { 424 425 return (EBADF); 426 } 427 428 /* 429 * Fifo advisory byte-level locks. 430 */ 431 /* ARGSUSED */ 432 fifo_advlock(ap) 433 struct vop_advlock_args /* { 434 struct vnode *a_vp; 435 caddr_t a_id; 436 int a_op; 437 struct flock *a_fl; 438 int a_flags; 439 } */ *ap; 440 { 441 442 return (EOPNOTSUPP); 443 } 444 445 /* 446 * Fifo bad operation 447 */ 448 fifo_badop() 449 { 450 451 panic("fifo_badop called"); 452 /* NOTREACHED */ 453 } 454