From d83cd7283c90cc791c70b5c8010c71f4c7144584 Mon Sep 17 00:00:00 2001
From: Richard Cochran <richardcochran@gmail.com>
Date: Sun, 25 Nov 2012 20:30:14 +0100
Subject: [PATCH] udp6: add an option to set the multicast scope.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
---
 config.c    | 5 +++++
 config.h    | 1 +
 default.cfg | 1 +
 ptp4l.c     | 2 ++
 udp6.c      | 4 ++++
 udp6.h      | 6 ++++++
 6 files changed, 19 insertions(+)

diff --git a/config.c b/config.c
index 9a9420f..7e31a33 100644
--- a/config.c
+++ b/config.c
@@ -255,6 +255,11 @@ static enum parser_result parse_global_setting(const char *option,
 		for (i = 0; i < MAC_LEN; i++)
 			cfg->p2p_dst_mac[i] = mac[i];
 
+	} else if (!strcmp(option, "udp6_scope")) {
+		if (1 != sscanf(value, "%hhx", &u8) || (u8 & 0xF0))
+			return BAD_VALUE;
+		*cfg->udp6_scope = u8;
+
 	} else if (!strcmp(option, "logging_level")) {
 		if (1 != sscanf(value, "%d", &val) ||
 				!(val >= PRINT_LEVEL_MIN && val <= PRINT_LEVEL_MAX))
diff --git a/config.h b/config.h
index b1f5fc6..5ceba9d 100644
--- a/config.h
+++ b/config.h
@@ -71,6 +71,7 @@ struct config {
 
 	unsigned char *ptp_dst_mac;
 	unsigned char *p2p_dst_mac;
+	unsigned char *udp6_scope;
 
 	int print_level;
 	int use_syslog;
diff --git a/default.cfg b/default.cfg
index 9b4fa73..9cf6bbf 100644
--- a/default.cfg
+++ b/default.cfg
@@ -43,6 +43,7 @@ clock_servo             pi
 transportSpecific	0x0
 ptp_dst_mac		01:1B:19:00:00:00
 p2p_dst_mac		01:80:C2:00:00:0E
+udp6_scope		0x0E
 #
 # Default interface options
 #
diff --git a/ptp4l.c b/ptp4l.c
index 572193f..1c9aad0 100644
--- a/ptp4l.c
+++ b/ptp4l.c
@@ -31,6 +31,7 @@
 #include "raw.h"
 #include "sk.h"
 #include "transport.h"
+#include "udp6.h"
 #include "util.h"
 
 int assume_two_step = 0;
@@ -78,6 +79,7 @@ static struct config cfg_settings = {
 
 	.ptp_dst_mac = ptp_dst_mac,
 	.p2p_dst_mac = p2p_dst_mac,
+	.udp6_scope = &udp6_scope,
 
 	.print_level = LOG_INFO,
 	.use_syslog = 1,
diff --git a/udp6.c b/udp6.c
index d8815c7..9e68574 100644
--- a/udp6.c
+++ b/udp6.c
@@ -40,6 +40,8 @@
 #define PTP_PRIMARY_MCAST_IP6ADDR "FF0E:0:0:0:0:0:0:181"
 #define PTP_PDELAY_MCAST_IP6ADDR  "FF02:0:0:0:0:0:0:6B"
 
+unsigned char udp6_scope = 0x0E;
+
 struct udp6 {
 	struct transport t;
 	int index;
@@ -160,6 +162,8 @@ static int udp6_open(struct transport *t, char *name, struct fdarray *fda,
 	if (1 != inet_pton(AF_INET6, PTP_PRIMARY_MCAST_IP6ADDR, &mc6_addr[MC_PRIMARY]))
 		return -1;
 
+	mc6_addr[MC_PRIMARY].s6_addr[1] = udp6_scope;
+
 	if (1 != inet_pton(AF_INET6, PTP_PDELAY_MCAST_IP6ADDR, &mc6_addr[MC_PDELAY]))
 		return -1;
 
diff --git a/udp6.h b/udp6.h
index 8613da5..e451262 100644
--- a/udp6.h
+++ b/udp6.h
@@ -23,6 +23,12 @@
 #include "fd.h"
 #include "transport.h"
 
+/**
+ * The desired scope for the multicast messages. This will be used as
+ * the second byte of the primary IPv6 address. See RFC 4291.
+ */
+extern unsigned char udp6_scope;
+
 /**
  * Allocate an instance of a UDP/IPv6 transport.
  * @return Pointer to a new transport instance on success, NULL otherwise.