udp6: add an option to set the multicast scope.

Signed-off-by: Richard Cochran <[email protected]>

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))

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;

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
 #

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,

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;
 

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.