Adds ability to ignore DHCP offers from multiple servers

- Forum thread: https://forum.pfsense.org/index.php?topic=124046.msg705100#msg705100
- related dhclient source:
https://github.com/pfsense/FreeBSD-src/blob/devel/sbin/dhclient/clparse.c#L945

**changed files:**
/usr/local/www/interfaces.php
/etc/inc/interfaces.inc

1 files changed, 21 insertions, 0 deletions

diff --git a/src/etc/inc/interfaces.inc b/src/etc/inc/interfaces.inc
index 40e5c27..e746e83 100644
--- a/src/etc/inc/interfaces.inc
+++ b/src/etc/inc/interfaces.inc
@@ -38,6 +38,27 @@ function interfaces_bring_up($interface) {
 }
 
 /*
+ * Validate comma-separated list of IPv4 addresses
+ */
+function validate_ipv4_list($value) {
+	$value = trim($value);
+
+	if (empty($value)) {
+		return false;
+	}
+
+	$list = explode(',', $value);
+
+	foreach ($list as $ip) {
+		if (!is_ipaddrv4($ip)) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/*
  * Return the interface array
  */
 function get_interface_arr($flush = false) {