[source] dnsmasq: Support add-mac option

[LEDE Commits]

blogic pushed a commit to source.git, branch master:
https://git.lede-project.org/a50243ea1f1fe28239a57283ef3a5ec6e8577dfb

commit a50243ea1f1fe28239a57283ef3a5ec6e8577dfb
Author: Hans Dedecker <dedeckeh at gmail.com>
AuthorDate: Thu Nov 3 21:44:29 2016 +0100

    dnsmasq: Support add-mac option
    
    Adds the mac address of the DNS requestor to DNS queries which
    are forwarded upstream and can be used to do filtering by the
    upstream servers. This only works if the requestor is on the
    same subnet as the dnsmasq server
    
    The addmac parameter can hold the following values:
    	0 : mac address is not added
    	1 : mac address is added in binary format
    	base64 : mac address is added base64 encoded
    	text: : mac address is added in human readable format
    		as hex and colons
    
    Signed-off-by: Hans Dedecker <dedeckeh at gmail.com>
---
 package/network/services/dnsmasq/Makefile           | 2 +-
 package/network/services/dnsmasq/files/dnsmasq.init | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/package/network/services/dnsmasq/Makefile b/package/network/services/dnsmasq/Makefile
index 804242f..861cda7 100644
--- a/package/network/services/dnsmasq/Makefile
+++ b/package/network/services/dnsmasq/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dnsmasq
 PKG_VERSION:=2.76
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=http://thekelleys.org.uk/dnsmasq
diff --git a/package/network/services/dnsmasq/files/dnsmasq.init b/package/network/services/dnsmasq/files/dnsmasq.init
index 7612830..b1f9e2e 100644
--- a/package/network/services/dnsmasq/files/dnsmasq.init
+++ b/package/network/services/dnsmasq/files/dnsmasq.init
@@ -660,6 +660,12 @@ dnsmasq_start()
 		append_bool "$cfg" dnsseccheckunsigned "--dnssec-check-unsigned"
 	}
 
+	config_get addmac "$cfg" addmac 0
+	[ "$addmac" != "0" ] && {
+		[ "$addmac" = "1" ] && addmac=
+		xappend "--add-mac${addmac:+="$addmac"}"
+	}
+
 	dhcp_option_add "$cfg" "" 0
 
 	xappend "--dhcp-broadcast=tag:needs-broadcast"