![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to fifo_vnops.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Net/2] / Net2 / miscfs / fifofs|
Return to fifo_vnops.c CVS log | Up to [Net/2] / Net2 / miscfs / fifofs |
1.1 root 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: fip->fi_readers=0;
134: fip->fi_writers=0;
135: if (error = socreate(AF_UNIX, &rso, SOCK_STREAM, 0)) {
136: free(fip, M_VNODE);
137: vp->v_fifoinfo = NULL;
138: return (error);
139: }
140: fip->fi_readsock = rso;
141: if (error = socreate(AF_UNIX, &wso, SOCK_STREAM, 0)) {
142: (void)soclose(rso);
143: free(fip, M_VNODE);
144: vp->v_fifoinfo = NULL;
145: return (error);
146: }
147: fip->fi_writesock = wso;
148: if (error = unp_connect2(wso, rso)) {
149: (void)soclose(wso);
150: (void)soclose(rso);
151: free(fip, M_VNODE);
152: vp->v_fifoinfo = NULL;
153: return (error);
154: }
155: wso->so_state |= SS_CANTRCVMORE;
156: rso->so_state |= SS_CANTSENDMORE;
157: }
158: error = 0;
159: if (mode & FREAD) {
160: fip->fi_readers++;
161: if (fip->fi_readers == 1) {
162: fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
163: if (fip->fi_writers > 0)
164: wakeup((caddr_t)&fip->fi_writers);
165: }
166: if (mode & O_NONBLOCK)
167: return (0);
168: while (fip->fi_writers == 0) {
169: VOP_UNLOCK(vp);
170: error = tsleep((caddr_t)&fip->fi_readers, PSOCK,
171: openstr, 0);
172: VOP_LOCK(vp);
173: if(error)
174: break;
175: }
176: } else {
177: fip->fi_writers++;
178: if (fip->fi_readers == 0 && (mode & O_NONBLOCK)) {
179: error = ENXIO;
180: } else {
181: if (fip->fi_writers == 1) {
182: fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
183: if (fip->fi_readers > 0)
184: wakeup((caddr_t)&fip->fi_readers);
185: }
186: while (fip->fi_readers == 0) {
187: VOP_UNLOCK(vp);
188: error = tsleep((caddr_t)&fip->fi_writers,
189: PSOCK, openstr, 0);
190: VOP_LOCK(vp);
191: if(error)
192: break;
193: }
194: }
195: }
196: if (error)
197: fifo_close(vp, mode, cred, p);
198: return (error);
199: }
200:
201: /*
202: * Vnode op for read
203: */
204: /* ARGSUSED */
205: fifo_read(vp, uio, ioflag, cred)
206: struct vnode *vp;
207: register struct uio *uio;
208: int ioflag;
209: struct ucred *cred;
210: {
211: register struct socket *rso = vp->v_fifoinfo->fi_readsock;
212: int error, startresid;
213:
214: #ifdef DIAGNOSTIC
215: if (uio->uio_rw != UIO_READ)
216: panic("fifo_read mode");
217: #endif
218: if (uio->uio_resid == 0)
219: return (0);
220: if (ioflag & IO_NDELAY)
221: rso->so_state |= SS_NBIO;
222: startresid = uio->uio_resid;
223: VOP_UNLOCK(vp);
224: error = soreceive(rso, (struct mbuf **)0, uio, (int *)0,
225: (struct mbuf **)0, (struct mbuf **)0);
226: VOP_LOCK(vp);
227: /*
228: * Clear EOF indication after first such return.
229: */
230: if (uio->uio_resid == startresid)
231: rso->so_state &= ~SS_CANTRCVMORE;
232: if (ioflag & IO_NDELAY)
233: rso->so_state &= ~SS_NBIO;
234: return (error);
235: }
236:
237: /*
238: * Vnode op for write
239: */
240: /* ARGSUSED */
241: fifo_write(vp, uio, ioflag, cred)
242: struct vnode *vp;
243: register struct uio *uio;
244: int ioflag;
245: struct ucred *cred;
246: {
247: struct socket *wso = vp->v_fifoinfo->fi_writesock;
248: int error;
249:
250: #ifdef DIAGNOSTIC
251: if (uio->uio_rw != UIO_WRITE)
252: panic("fifo_write mode");
253: #endif
254: if (ioflag & IO_NDELAY)
255: wso->so_state |= SS_NBIO;
256: VOP_UNLOCK(vp);
257: error = sosend(wso, (struct mbuf *)0, uio, 0, (struct mbuf *)0);
258: VOP_LOCK(vp);
259: if (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(vp, com, data, fflag, cred, p)
269: struct vnode *vp;
270: int com;
271: caddr_t data;
272: int fflag;
273: struct ucred *cred;
274: struct proc *p;
275: {
276: struct file filetmp;
277: int error;
278:
279: if (com == FIONBIO)
280: return (0);
281: if (fflag & FREAD)
282: filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
283: else
284: filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
285: return (soo_ioctl(&filetmp, com, data, p));
286: }
287:
288: /* ARGSUSED */
289: fifo_select(vp, which, fflag, cred, p)
290: struct vnode *vp;
291: int which, fflag;
292: struct ucred *cred;
293: struct proc *p;
294: {
295: struct file filetmp;
296: int error;
297:
298: if (fflag & FREAD)
299: filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_readsock;
300: else
301: filetmp.f_data = (caddr_t)vp->v_fifoinfo->fi_writesock;
302: return (soo_select(&filetmp, which, p));
303: }
304:
305: /*
306: * This is a noop, simply returning what one has been given.
307: */
308: fifo_bmap(vp, bn, vpp, bnp)
309: struct vnode *vp;
310: daddr_t bn;
311: struct vnode **vpp;
312: daddr_t *bnp;
313: {
314:
315: if (vpp != NULL)
316: *vpp = vp;
317: if (bnp != NULL)
318: *bnp = bn;
319: return (0);
320: }
321:
322: /*
323: * At the moment we do not do any locking.
324: */
325: /* ARGSUSED */
326: fifo_lock(vp)
327: struct vnode *vp;
328: {
329:
330: return (0);
331: }
332:
333: /* ARGSUSED */
334: fifo_unlock(vp)
335: struct vnode *vp;
336: {
337:
338: return (0);
339: }
340:
341: /*
342: * Device close routine
343: */
344: /* ARGSUSED */
345: fifo_close(vp, fflag, cred, p)
346: register struct vnode *vp;
347: int fflag;
348: struct ucred *cred;
349: struct proc *p;
350: {
351: register struct fifoinfo *fip = vp->v_fifoinfo;
352: int error1, error2;
353:
354: if (fflag & FWRITE) {
355: fip->fi_writers--;
356: if (fip->fi_writers == 0)
357: socantrcvmore(fip->fi_readsock);
358: } else {
359: fip->fi_readers--;
360: if (fip->fi_readers == 0)
361: socantsendmore(fip->fi_writesock);
362: }
363: if (vp->v_usecount > 1)
364: return (0);
365: error1 = soclose(fip->fi_readsock);
366: error2 = soclose(fip->fi_writesock);
367: FREE(fip, M_VNODE);
368: vp->v_fifoinfo = NULL;
369: if (error1)
370: return (error1);
371: return (error2);
372: }
373:
374: /*
375: * Print out the contents of a fifo vnode.
376: */
377: fifo_print(vp)
378: struct vnode *vp;
379: {
380:
381: printf("tag VT_NON");
382: fifo_printinfo(vp);
383: printf("\n");
384: }
385:
386: /*
387: * Print out internal contents of a fifo vnode.
388: */
389: fifo_printinfo(vp)
390: struct vnode *vp;
391: {
392: register struct fifoinfo *fip = vp->v_fifoinfo;
393:
394: printf(", fifo with %d readers and %d writers",
395: fip->fi_readers, fip->fi_writers);
396: }
397:
398: /*
399: * Fifo failed operation
400: */
401: fifo_ebadf()
402: {
403:
404: return (EBADF);
405: }
406:
407: /*
408: * Fifo advisory byte-level locks.
409: */
410: /* ARGSUSED */
411: fifo_advlock(vp, id, op, fl, flags)
412: struct vnode *vp;
413: caddr_t id;
414: int op;
415: struct flock *fl;
416: int flags;
417: {
418:
419: return (EOPNOTSUPP);
420: }
421:
422: /*
423: * Fifo bad operation
424: */
425: fifo_badop()
426: {
427:
428: panic("fifo_badop called");
429: /* NOTREACHED */
430: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.