From 7fc2ce8ae47e93bf7617e83c8426b8852d0cfea8 Mon Sep 17 00:00:00 2001
From: Yaroslav Tykhiy <ytykhiy@gmail.com>
Date: Tue, 4 Oct 2005 11:48:03 +0000
Subject: [PATCH] Use a callback to set up a vlan interface so that "vlan" and
 "vlandev" commands can be specified in any order. This makes the code more
 compact and clear as well.

Improve error check on vlan argument.

MFC after:	2 weeks
---
 sbin/ifconfig/ifvlan.c | 66 +++++++++++++++++++-----------------------
 1 file changed, 30 insertions(+), 36 deletions(-)

diff --git a/sbin/ifconfig/ifvlan.c b/sbin/ifconfig/ifvlan.c
index 361f415c1859..7b8500328322 100644
--- a/sbin/ifconfig/ifvlan.c
+++ b/sbin/ifconfig/ifvlan.c
@@ -58,7 +58,8 @@
 static const char rcsid[] =
   "$FreeBSD$";
 #endif
-static int			__tag = 0;
+static struct vlanreq		__vreq;
+static int			__have_dev = 0;
 static int			__have_tag = 0;
 
 static void
@@ -82,47 +83,26 @@ vlan_status(int s)
 static void
 setvlantag(const char *val, int d, int s, const struct afswtch	*afp)
 {
-	u_int16_t		tag;
-	struct vlanreq		vreq;
+	char			*endp;
+	u_long			ul;
 
-	__tag = tag = atoi(val);
+	ul = strtoul(val, &endp, 0);
+	if (*endp != '\0')
+		errx(1, "invalid value for vlan");
+	__vreq.vlr_tag = ul;
+	/* check if the value can be represented in vlr_tag */
+	if (__vreq.vlr_tag != ul)
+		errx(1, "value for vlan out of range");
+	/* the kernel will do more specific checks on vlr_tag */
 	__have_tag = 1;
-
-	bzero((char *)&vreq, sizeof(struct vlanreq));
-	ifr.ifr_data = (caddr_t)&vreq;
-
-	if (ioctl(s, SIOCGETVLAN, (caddr_t)&ifr) == -1)
-		err(1, "SIOCGETVLAN");
-
-	vreq.vlr_tag = tag;
-
-	if (ioctl(s, SIOCSETVLAN, (caddr_t)&ifr) == -1)
-		err(1, "SIOCSETVLAN");
-
-	return;
 }
 
 static void
 setvlandev(const char *val, int d, int s, const struct afswtch	*afp)
 {
-	struct vlanreq		vreq;
 
-	if (!__have_tag)
-		errx(1, "must specify both vlan tag and device");
-
-	bzero((char *)&vreq, sizeof(struct vlanreq));
-	ifr.ifr_data = (caddr_t)&vreq;
-
-	if (ioctl(s, SIOCGETVLAN, (caddr_t)&ifr) == -1)
-		err(1, "SIOCGETVLAN");
-
-	strncpy(vreq.vlr_parent, val, sizeof(vreq.vlr_parent));
-	vreq.vlr_tag = __tag;
-
-	if (ioctl(s, SIOCSETVLAN, (caddr_t)&ifr) == -1)
-		err(1, "SIOCSETVLAN");
-
-	return;
+	strncpy(__vreq.vlr_parent, val, sizeof(__vreq.vlr_parent));
+	__have_dev = 1;
 }
 
 static void
@@ -140,12 +120,25 @@ unsetvlandev(const char *val, int d, int s, const struct afswtch *afp)
 		err(1, "SIOCGETVLAN");
 
 	bzero((char *)&vreq.vlr_parent, sizeof(vreq.vlr_parent));
-	vreq.vlr_tag = 0;
+	vreq.vlr_tag = 0; /* XXX clear parent only (no kernel support now) */
 
 	if (ioctl(s, SIOCSETVLAN, (caddr_t)&ifr) == -1)
 		err(1, "SIOCSETVLAN");
+	__have_dev = __have_tag = 0;
+}
 
-	return;
+static void
+vlan_cb(int s, void *arg)
+{
+
+	if (__have_tag ^ __have_dev)
+		errx(1, "both vlan and vlandev must be specified");
+
+	if (__have_tag && __have_dev) {
+		ifr.ifr_data = (caddr_t)&__vreq;
+		if (ioctl(s, SIOCSETVLAN, (caddr_t)&ifr) == -1)
+			err(1, "SIOCSETVLAN");
+	}
 }
 
 static struct cmd vlan_cmds[] = {
@@ -173,5 +166,6 @@ vlan_ctor(void)
 	for (i = 0; i < N(vlan_cmds);  i++)
 		cmd_register(&vlan_cmds[i]);
 	af_register(&af_vlan);
+	callback_register(vlan_cb, NULL);
 #undef N
 }