[LEDE-DEV] [netifd] Fix incorrect eui64 IPv6 address with ula prefix for br-lan

[wendy2001011 at 163.com]

From: Wendy Wu <wendy2001011 at 163.com>

Issue description:
Configurate /etc/config/network,
Set the ula_prefix in globals section,
config globals 'globals'
        option ula_prefix 'fdc7:8830:f3be::/48'
Add the following option in 'lan' interface,
option ip6ifaceid 'eui64'
Then execute /etc/init.d/network, the br-lan ipv6 address with ula_prefix is incorrect.
Result see the following, fdc7:8830:f3be:0:200:ff:fe00:0/64 is incorrect address
root at mygateway:~# ifconfig br-lan
    br-lan    Link encap:Ethernet  HWaddr E0:B9:E5:66:94:DE
              inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
              inet6 addr: fe80::e2b9:e5ff:fe66:94de/64 Scope:Link
              inet6 addr: fdc7:8830:f3be:0:200:ff:fe00:0/64 Scope:Global
              inet6 addr: 4085:6666:f:e7e0:e2b9:e5ff:fe66:94de/64 Scope:Global
              UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
              RX packets:17 errors:0 dropped:0 overruns:0 frame:0
              TX packets:281 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:0
              RX bytes:2262 (2.2 KiB)  TX bytes:111905 (109.2 KiB)

After the fix, fdc7:8830:f3be:0:e2b9:e5ff:fe66:94de/64 is correct address
See the following,
root at mygateway:~# ifconfig br-lan
    br-lan    Link encap:Ethernet  HWaddr E0:B9:E5:66:94:DE
              inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
              inet6 addr: fe80::e2b9:e5ff:fe66:94de/64 Scope:Link
              inet6 addr: 4085:6666:f:b130:e2b9:e5ff:fe66:94de/64 Scope:Global
              inet6 addr: fdc7:8830:f3be:0:e2b9:e5ff:fe66:94de/64 Scope:Global
              UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
              RX packets:2462 errors:0 dropped:0 overruns:0 frame:0
              TX packets:31072 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:0
              RX bytes:115038 (112.3 KiB)  TX bytes:12676812 (12.0 MiB)

Root cause:
When eui64 ipv6 address with ula_prefix for br-lan is created, the lan interface setting has not been ready.
So The mac address for br-lan is null, and the eui64 address with ula_prefix is incorrect.

Solution:
Put the ula_prefix global initial part after device pending

Signed-off-by: wendy wu <wendy2001011 at 163.com>
---
 config.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/config.c b/config.c
index 21791af..a494e84 100644
--- a/config.c
+++ b/config.c
@@ -310,10 +310,6 @@ config_init_globals(void)
 	if (!globals)
 		return;
 
-	const char *ula_prefix = uci_lookup_option_string(
-			uci_ctx, globals, "ula_prefix");
-	interface_ip_set_ula_prefix(ula_prefix);
-
 	const char *default_ps = uci_lookup_option_string(
 			uci_ctx, globals, "default_ps");
 
@@ -324,6 +320,21 @@ config_init_globals(void)
 			config_parse_global_ps_val(globals, "default_rps_flow_cnt"));
 }
 
+static void
+config_init_globals_ula(void)
+{
+        struct uci_section *globals = uci_lookup_section(
+                        uci_ctx, uci_network, "globals");
+        if (!globals)
+                return;
+
+        const char *ula_prefix = uci_lookup_option_string(
+                        uci_ctx, globals, "ula_prefix");
+
+        interface_ip_set_ula_prefix(ula_prefix);
+
+}
+
 static void
 config_parse_wireless_device(struct uci_section *s)
 {
@@ -447,6 +458,7 @@ config_init_all(void)
 
 	device_reset_old();
 	device_init_pending();
+        config_init_globals_ula();
 	vlist_flush(&interfaces);
 	device_free_unused(NULL);
 	interface_refresh_assignments(false);
-- 
2.15.1