Add a new kqfilter for random which returns ARC4_MAIN_MAX_BYTES for read

and POOLBYTES for write.

looks right to deraadt

2 files changed, 52 insertions, 6 deletions

diff --git a/sys/dev/rnd.c b/sys/dev/rnd.c
index 0c6ff53540a..9beb232b963 100644
--- a/sys/dev/rnd.c
+++ b/sys/dev/rnd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rnd.c,v 1.139 2011/01/11 06:15:03 djm Exp $	*/
+/*	$OpenBSD: rnd.c,v 1.140 2011/07/06 14:49:30 nicm Exp $	*/
 
 /*
  * Copyright (c) 2011 Theo de Raadt.
@@ -112,6 +112,7 @@
 #include <sys/systm.h>
 #include <sys/conf.h>
 #include <sys/disk.h>
+#include <sys/event.h>
 #include <sys/limits.h>
 #include <sys/time.h>
 #include <sys/ioctl.h>
@@ -224,9 +225,18 @@ u_int32_t entropy_pool[POOLWORDS];
 u_int	entropy_add_ptr;
 u_char	entropy_input_rotate;
 
-void dequeue_randomness(void *);
-void add_entropy_words(const u_int32_t *, u_int);
-void extract_entropy(u_int8_t *buf, int nbytes);
+void	dequeue_randomness(void *);
+void	add_entropy_words(const u_int32_t *, u_int);
+void	extract_entropy(u_int8_t *, int);
+
+int	filt_randomread(struct knote *, long);
+void	filt_randomdetach(struct knote *);
+int	filt_randomwrite(struct knote *, long);
+
+struct filterops randomread_filtops =
+	{ 1, NULL, filt_randomdetach, filt_randomread };
+struct filterops randomwrite_filtops =
+	{ 1, NULL, filt_randomdetach, filt_randomwrite };
 
 static __inline struct rand_event *
 rnd_get(void)
@@ -783,6 +793,42 @@ randomwrite(dev_t dev, struct uio *uio, int flags)
 }
 
 int
+randomkqfilter(dev_t dev, struct knote *kn)
+{
+	switch (kn->kn_filter) {
+	case EVFILT_READ:
+		kn->kn_fop = &randomread_filtops;
+		break;
+	case EVFILT_WRITE:
+		kn->kn_fop = &randomwrite_filtops;
+		break;
+	default:
+		return (EINVAL);
+	}
+
+	return (0);
+}
+
+void
+filt_randomdetach(struct knote *kn)
+{
+}
+
+int
+filt_randomread(struct knote *kn, long hint)
+{
+	kn->kn_data = ARC4_MAIN_MAX_BYTES;
+	return (1);
+}
+
+int
+filt_randomwrite(struct knote *kn, long hint)
+{
+	kn->kn_data = POOLBYTES;
+	return (1);
+}
+
+int
 randomioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
 {
 	switch (cmd) {
diff --git a/sys/sys/conf.h b/sys/sys/conf.h
index e0e34f91342..388215ddc89 100644
--- a/sys/sys/conf.h
+++ b/sys/sys/conf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: conf.h,v 1.114 2011/07/04 22:53:53 tedu Exp $	*/
+/*	$OpenBSD: conf.h,v 1.115 2011/07/06 14:49:30 nicm Exp $	*/
 /*	$NetBSD: conf.h,v 1.33 1996/05/03 20:03:32 christos Exp $	*/
 
 /*-
@@ -383,7 +383,7 @@ extern struct cdevsw cdevsw[];
 	dev_init(c,n,open), dev_init(c,n,close), dev_init(c,n,read), \
 	dev_init(c,n,write), dev_init(c,n,ioctl), (dev_type_stop((*))) enodev, \
 	0, seltrue, (dev_type_mmap((*))) enodev, \
-	0, 0, seltrue_kqfilter }
+	0, 0, dev_init(c,n,kqfilter) }
 
 /* open, close, ioctl, poll, nokqfilter */
 #define	cdev_usb_init(c,n) { \