Revert 8532 "Ensure only temporary IPv6 address is selected as t..."
> Ensure only temporary IPv6 address is selected as the best IP.
>
> The current logic of IPv6 selection could still have a small chance for non-temporary address to be selected for candidate. The scenario is that when there is no non-deprecated temporary IP, the global ones could be selected.
>
> Global ones don't necessarily carry MAC. However, instead of comparing whether it has the MAC in it (sometimes 5 out of 6 elements from a MAC are the same, only one diffs), we should just err on the safe side.
>
> BUG=4348
> R=juberti@webrtc.org, pthatcher@webrtc.org
>
> Review URL: https://webrtc-codereview.appspot.com/38289004
TBR=guoweis@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/38319004
Cr-Commit-Position: refs/heads/master@{#8534}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8534 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/base/network.cc b/webrtc/base/network.cc
index ad1b47d..bbebe8a 100644
--- a/webrtc/base/network.cc
+++ b/webrtc/base/network.cc
@@ -719,8 +719,7 @@
return changed;
}
-// Select the best IP address to use from this Network. For IPv6 addresses, we
-// only allow temporary IPv6 addresses to be selected to prevent MAC tracking.
+// Select the best IP address to use from this Network.
IPAddress Network::GetBestIP() const {
if (ips_.size() == 0) {
return IPAddress();
@@ -730,17 +729,32 @@
return static_cast<IPAddress>(ips_.at(0));
}
+ InterfaceAddress selected_ip, ula_ip;
+
for (const InterfaceAddress& ip : ips_) {
- // Ignore all deprecated and non-temporary addresses.
- if ((ip.ipv6_flags() & IPV6_ADDRESS_FLAG_DEPRECATED) ||
- !(ip.ipv6_flags() & IPV6_ADDRESS_FLAG_TEMPORARY)) {
+ // Ignore any address which has been deprecated already.
+ if (ip.ipv6_flags() & IPV6_ADDRESS_FLAG_DEPRECATED)
+ continue;
+
+ // ULA address should only be returned when we have no other
+ // global IP.
+ if (IPIsULA(static_cast<const IPAddress&>(ip))) {
+ ula_ip = ip;
continue;
}
+ selected_ip = ip;
- return static_cast<IPAddress>(ip);
+ // Search could stop once a temporary non-deprecated one is found.
+ if (ip.ipv6_flags() & IPV6_ADDRESS_FLAG_TEMPORARY)
+ break;
}
- return IPAddress();
+ // No proper global IPv6 address found, use ULA instead.
+ if (IPIsUnspec(selected_ip) && !IPIsUnspec(ula_ip)) {
+ selected_ip = ula_ip;
+ }
+
+ return static_cast<IPAddress>(selected_ip);
}
std::string Network::ToString() const {
diff --git a/webrtc/base/network.h b/webrtc/base/network.h
index 6f9f881..089d86b 100644
--- a/webrtc/base/network.h
+++ b/webrtc/base/network.h
@@ -236,9 +236,24 @@
// interfaces. Key is derived from interface name and it's prefix.
std::string key() const { return key_; }
- // Returns the Network's current idea of the 'best' IP it has. For privacy
- // reasons, in the case of IPv6, only temporary addresses will be selected.
- // Additionally, the unique local address (ULA) will never be selected.
+ // Returns the Network's current idea of the 'best' IP it has.
+ // Or return an unset IP if this network has no active addresses.
+ // Here is the rule on how we mark the IPv6 address as ignorable for WebRTC.
+ // 1) return all global temporary dynamic and non-deprecrated ones.
+ // 2) if #1 not available, return global ones.
+ // 3) if #2 not available, use ULA ipv6 as last resort. (ULA stands
+ // for unique local address, which is not route-able in open
+ // internet but might be useful for a close WebRTC deployment.
+
+ // TODO(guoweis): rule #3 actually won't happen at current
+ // implementation. The reason being that ULA address starting with
+ // 0xfc 0r 0xfd will be grouped into its own Network. The result of
+ // that is WebRTC will have one extra Network to generate candidates
+ // but the lack of rule #3 shouldn't prevent turning on IPv6 since
+ // ULA should only be tried in a close deployment anyway.
+
+ // Note that when not specifying any flag, it's treated as case global
+ // IPv6 address
IPAddress GetBestIP() const;
// Keep the original function here for now.
diff --git a/webrtc/base/network_unittest.cc b/webrtc/base/network_unittest.cc
index 3934593..662dc70 100644
--- a/webrtc/base/network_unittest.cc
+++ b/webrtc/base/network_unittest.cc
@@ -759,20 +759,18 @@
ipv6_network.AddIP(ip);
EXPECT_EQ(ipv6_network.GetBestIP(), IPAddress());
- // Add ULA one. ULA is the unique local address which starts with either 0xfc
- // or 0xfd. Since it doesn't have the temporary address attribute, it'll be
- // ignored.
+ // Add ULA one. ULA is unique local address which is starting either
+ // with 0xfc or 0xfd.
ipstr = "fd00:fa00:4:1000:be30:5bff:fee5:c4";
ASSERT_TRUE(IPFromString(ipstr, IPV6_ADDRESS_FLAG_NONE, &ip));
ipv6_network.AddIP(ip);
- EXPECT_EQ(ipv6_network.GetBestIP(), IPAddress());
+ EXPECT_EQ(ipv6_network.GetBestIP(), static_cast<IPAddress>(ip));
- // Add global one. Since it doesn't have the temporary address attribute,
- // it'll be ignored.
+ // Add global one.
ipstr = "2401:fa00:4:1000:be30:5bff:fee5:c5";
ASSERT_TRUE(IPFromString(ipstr, IPV6_ADDRESS_FLAG_NONE, &ip));
ipv6_network.AddIP(ip);
- EXPECT_EQ(ipv6_network.GetBestIP(), IPAddress());
+ EXPECT_EQ(ipv6_network.GetBestIP(), static_cast<IPAddress>(ip));
// Add global dynamic temporary one.
ipstr = "2401:fa00:4:1000:be30:5bff:fee5:c6";
