Replace select backends with poll backends. selscan() and pollscan()

now call the poll backend.  With this change we implement greater
poll(2) functionality instead of emulating it via the select backend.
Adapted from NetBSD and including some changes from FreeBSD.
Tested by many, deraadt@ OK

1 files changed, 18 insertions, 26 deletions

diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index f2e09c84d78..7e42edc8e62 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bpf.c,v 1.37 2003/07/29 23:02:52 itojun Exp $	*/
+/*	$OpenBSD: bpf.c,v 1.38 2003/09/23 16:51:13 millert Exp $	*/
 /*	$NetBSD: bpf.c,v 1.33 1997/02/21 23:59:35 thorpej Exp $	*/
 
 /*
@@ -48,6 +48,7 @@
 #include <sys/vnode.h>
 #include <sys/file.h>
 #include <sys/socket.h>
+#include <sys/poll.h>
 #include <sys/kernel.h>
 
 #include <net/if.h>
@@ -83,7 +84,7 @@ int	bpf_movein(struct uio *, int, struct mbuf **, struct sockaddr *);
 void	bpf_attachd(struct bpf_d *, struct bpf_if *);
 void	bpf_detachd(struct bpf_d *);
 int	bpf_setif(struct bpf_d *, struct ifreq *);
-int	bpfselect(dev_t, int, struct proc *);
+int	bpfpoll(dev_t, int, struct proc *);
 int	bpfkqfilter(dev_t, struct knote *);
 static __inline void bpf_wakeup(struct bpf_d *);
 void	bpf_catchpacket(struct bpf_d *, u_char *, size_t, size_t,
@@ -928,46 +929,37 @@ bpf_ifname(ifp, ifr)
 }
 
 /*
- * Support for select() system call
- *
- * Return true iff the specific operation will not block indefinitely.
- * Otherwise, return false but make a note that a selwakeup() must be done.
+ * Support for poll() system call
  */
 int
-bpfselect(dev, rw, p)
+bpfpoll(dev, events, p)
 	register dev_t dev;
-	int rw;
+	int events;
 	struct proc *p;
 {
 	register struct bpf_d *d;
-	register int s;
+	register int s, revents;
+
+	revents = events & (POLLIN | POLLRDNORM);
+	if (revents == 0)
+		return (0);		/* only support reading */
 
-	if (rw != FREAD)
-		return (0);
 	/*
 	 * An imitation of the FIONREAD ioctl code.
 	 */
 	d = &bpf_dtab[minor(dev)];
-
 	s = splimp();
-	if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) {
+	if (d->bd_hlen == 0 && (!d->bd_immediate || d->bd_slen == 0)) {
+		revents = 0;		/* no data waiting */
 		/*
-		 * There is data waiting.
+		 * if there's a timeout, mark the time we started waiting.
 		 */
-		splx(s);
-		return (1);
+		if (d->bd_rtout != -1 && d->bd_rdStart == 0)
+			d->bd_rdStart = ticks;
+		selrecord(p, &d->bd_sel);
 	}
-
-	/*
-	 * if there isn't data waiting, and there's a timeout,
-	 * mark the time we started waiting.
-	 */
-	if (d->bd_rtout != -1 && d->bd_rdStart == 0)
-		d->bd_rdStart = ticks;
-			    
-	selrecord(p, &d->bd_sel);
 	splx(s);
-	return (0);
+	return (revents);
 }
 
 struct filterops bpfread_filtops =