Switch bpf to use pgsigio(9) and sigio_init(9) instead of handrolling

something with csignal().
OK visa@

2 files changed, 18 insertions, 16 deletions

diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index 6c23b4581b7..01ddec71af8 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bpf.c,v 1.183 2019/12/31 13:48:32 visa Exp $	*/
+/*	$OpenBSD: bpf.c,v 1.184 2020/01/02 16:23:01 claudio Exp $	*/
 /*	$NetBSD: bpf.c,v 1.33 1997/02/21 23:59:35 thorpej Exp $	*/
 
 /*
@@ -58,6 +58,7 @@
 #include <sys/smr.h>
 #include <sys/specdev.h>
 #include <sys/selinfo.h>
+#include <sys/sigio.h>
 #include <sys/task.h>
 
 #include <net/if.h>
@@ -376,6 +377,7 @@ bpfopen(dev_t dev, int flag, int mode, struct proc *p)
 	mtx_init(&bd->bd_mtx, IPL_NET);
 	task_set(&bd->bd_wake_task, bpf_wakeup_cb, bd);
 	smr_init(&bd->bd_smr);
+	sigio_init(&bd->bd_sigio);
 
 	if (flag & FNONBLOCK)
 		bd->bd_rtout = -1;
@@ -556,7 +558,7 @@ bpf_wakeup(struct bpf_d *d)
 	MUTEX_ASSERT_LOCKED(&d->bd_mtx);
 
 	/*
-	 * As long as csignal() and selwakeup() need to be protected
+	 * As long as pgsigio() and selwakeup() need to be protected
 	 * by the KERNEL_LOCK() we have to delay the wakeup to
 	 * another context to keep the hot path KERNEL_LOCK()-free.
 	 */
@@ -574,7 +576,7 @@ bpf_wakeup_cb(void *xd)
 
 	wakeup(d);
 	if (d->bd_async && d->bd_sig)
-		csignal(d->bd_pgid, d->bd_sig, d->bd_siguid, d->bd_sigeuid);
+		pgsigio(&d->bd_sigio, d->bd_sig, 0);
 
 	selwakeup(&d->bd_sel);
 	bpf_put(d);
@@ -972,19 +974,19 @@ bpfioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
 	/*
 	 * N.B.  ioctl (FIOSETOWN) and fcntl (F_SETOWN) both end up doing
 	 * the equivalent of a TIOCSPGRP and hence end up here.  *However*
-	 * TIOCSPGRP's arg is a process group if it's positive and a process
-	 * id if it's negative.  This is exactly the opposite of what the
-	 * other two functions want!  Therefore there is code in ioctl and
-	 * fcntl to negate the arg before calling here.
+	 * TIOCSPGRP's arg is a process group. Therefore there is code in
+	 * ioctl and fcntl to negate the arg before calling here.
 	 */
 	case TIOCSPGRP:		/* Process or group to send signals to */
-		d->bd_pgid = *(int *)addr;
-		d->bd_siguid = p->p_ucred->cr_ruid;
-		d->bd_sigeuid = p->p_ucred->cr_uid;
+		if (*(int *)addr < 0) {
+			error = EINVAL;
+			break;
+		}
+		error = sigio_setown(&d->bd_sigio, -*(int *)addr);
 		break;
 
 	case TIOCGPGRP:
-		*(int *)addr = d->bd_pgid;
+		*(int *)addr = -sigio_getown(&d->bd_sigio);
 		break;
 
 	case BIOCSRSIG:		/* Set receive signal */
@@ -1587,6 +1589,7 @@ bpf_d_smr(void *smr)
 {
 	struct bpf_d	*bd = smr;
 
+	sigio_free(&bd->bd_sigio);
 	free(bd->bd_sbuf, M_DEVBUF, bd->bd_bufsize);
 	free(bd->bd_hbuf, M_DEVBUF, bd->bd_bufsize);
 	free(bd->bd_fbuf, M_DEVBUF, bd->bd_bufsize);
diff --git a/sys/net/bpfdesc.h b/sys/net/bpfdesc.h
index ab0b743341d..41b65116b41 100644
--- a/sys/net/bpfdesc.h
+++ b/sys/net/bpfdesc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bpfdesc.h,v 1.39 2019/10/21 23:02:05 sashan Exp $	*/
+/*	$OpenBSD: bpfdesc.h,v 1.40 2020/01/02 16:23:01 claudio Exp $	*/
 /*	$NetBSD: bpfdesc.h,v 1.11 1995/09/27 18:30:42 thorpej Exp $	*/
 
 /*
@@ -90,15 +90,14 @@ struct bpf_d {
 	int		bd_hdrcmplt;	/* false to fill in src lladdr automatically */
 	int		bd_async;	/* non-zero if packet reception should generate signal */
 	int		bd_sig;		/* signal to send upon packet reception */
-	pid_t		bd_pgid;	/* process or group id for signal */
-	uid_t		bd_siguid;	/* uid for process that set pgid */
-	uid_t		bd_sigeuid;	/* euid for process that set pgid */
+	struct sigio_ref
+			bd_sigio;	/* async I/O registration */
 	u_int		bd_ref;		/* reference count */
 	struct selinfo	bd_sel;		/* bsd select info */
 	int		bd_unit;	/* logical unit number */
 	LIST_ENTRY(bpf_d) bd_list;	/* descriptor list */
 
-	struct task	bd_wake_task;	/* delay csignal() and selwakeup() */
+	struct task	bd_wake_task;	/* delay pgsigio() and selwakeup() */
 
 	struct smr_entry
 			bd_smr;