kernel/3174: Add kqueue(2) support to tun(4)

From: <wayne(at)epipe.com.au>
Date: Sat Mar 29 2003 - 22:29:59 EST

>Number:         3174
>Category:       kernel
>Synopsis:       Add kqueue(2) support to tun(4)
>Confidential:   yes
>Severity:       non-critical
>Priority:       low
>Responsible:    bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 30 03:40:01 GMT 2003
>Closed-Date:
>Last-Modified:
>Originator:     
>Release:        3.3-current (cvs as at March 30)
>Organization:

net
>Environment:

	System      : OpenBSD 3.3
	Architecture: OpenBSD.i386
	Machine     : i386
>Description:
	The tun(4) interface currently lacks support for kqueue(2)/kevent(2).

	This patch adds support.  Partially from NetBSD.

>How-To-Repeat:
	Try to register kevent(2) EVFILT_READ or EVFILT_WRITE events on tun(4)

>Fix:

Index: sys/net/if_tun.c

---

RCS file: /cvs/src/sys/net/if_tun.c,v
retrieving revision 1.45
diff -u -r1.45 if_tun.c

--- sys/net/if_tun.c	2003/01/07 09:00:34	1.45


+++ sys/net/if_tun.c	2003/03/30 03:14:20

@@ -136,6 +136,10 @@
 #ifdef ALTQ
 static void tunstart(struct ifnet *);
 #endif
+int filt_tunread(struct knote *, long);
+int filt_tunwrite(struct knote *, long);
+void filt_tunrdetach(struct knote *);
+void filt_tunwdetach(struct knote *);
 

 void
 tunattach(n)
@@ -416,6 +420,7 @@

 		csignal(tp->tun_pgid, SIGIO,
 		    tp->tun_siguid, tp->tun_sigeuid);
 	selwakeup(&tp->tun_rsel);


+	KNOTE(&tp->tun_rsel.si_note, 0);


 	return 0;

 }  

@@ -759,11 +764,96 @@

         return 0;
 }  

-/* Does not currently work */
+struct filterops tunread_filtops =
+ { 1, NULL, filt_tunrdetach, filt_tunread };
 

+struct filterops tunwrite_filtops =
+ { 1, NULL, filt_tunwdetach, filt_tunwrite };
+

 int
-tunkqfilter(dev_t dev,struct knote *kn)
+tunkqfilter(dev_t dev, struct knote *kn)
 {
+ struct klist *klist;
+ struct tun_softc *tp;
+ int unit, s;
+
+ if ((unit = minor(dev)) >= ntun)
+ return (1);
+
+ tp = &tunctl[unit];
+
+ switch (kn->kn_filter) {
+ case EVFILT_READ:
+ klist = &tp->tun_rsel.si_note;
+ kn->kn_fop = &tunread_filtops;
+ break;
+ case EVFILT_WRITE:
+ klist = &tp->tun_wsel.si_note;
+ kn->kn_fop = &tunwrite_filtops;
+ break;
+ default:
+ return (1);
+ }
+ kn->kn_hook = (caddr_t)tp;
+
+ s = splimp();
+ SLIST_INSERT_HEAD(klist, kn, kn_selnext);
+ splx(s);
+
+ return (0);
+}
+
+void
+filt_tunrdetach(struct knote *kn)
+{
+ struct tun_softc *tp = (struct tun_softc *)kn->kn_hook;
+ int s;
+
+ s = splimp();
+ SLIST_REMOVE(&tp->tun_rsel.si_note, kn, knote, kn_selnext);
+ splx(s);
+}
+
+void
+filt_tunwdetach(struct knote *kn)
+{
+ struct tun_softc *tp = (struct tun_softc *)kn->kn_hook;
+ int s;
+
+ s = splimp();
+ SLIST_REMOVE(&tp->tun_wsel.si_note, kn, knote, kn_selnext);
+ splx(s);
+}
+
+int
+filt_tunread(struct knote *kn, long hint)
+{
+ struct tun_softc *tp = (struct tun_softc *)kn->kn_hook;
+ struct ifnet *ifp = &tp->tun_if;
+ struct mbuf *m;
+ int s;
+
+ s = splnet();
+ IF_POLL(&ifp->if_snd, m);
+ if (m == NULL) {
+ splx(s);
+ return (0);
+ }
+
+ for (kn->kn_data = 0; m != NULL; m = m->m_next)
+ kn->kn_data += m->m_len;
+
+ splx(s);
+ return (1);
+}
+
+int
+filt_tunwrite(struct knote *kn, long hint)
+{
+ struct tun_softc *tp = (struct tun_softc *)kn->kn_hook;
+ struct ifnet *ifp = &tp->tun_if;
+
+ kn->kn_data = ifp->if_mtu;

         return (1);
 }  

@@ -794,6 +884,7 @@

 			csignal(tp->tun_pgid, SIGIO,
 			    tp->tun_siguid, tp->tun_sigeuid);
 		selwakeup(&tp->tun_rsel);


+		KNOTE(&tp->tun_rsel.si_note, 0);


 	}

 }
 #endif

>Release-Note:
>Audit-Trail:
>Unformatted:

Received on Sat Mar 29 22:46:33 2003