platform: remove padding for IP address lifetimes

We used to pad the lifetime since the beginning (commit
f121995fad93eda886b2a34a8d79a45a5688b917).

However, there is not race involved, since our platform cache
is in sync with the messages from kernel (which didn't used to
be the case).

Also, when receiving a RA with a zero preferred time, we must
not extend the address lifetime by 5 seconds, but instead deprecate
the address immediately.

https://bugzilla.gnome.org/show_bug.cgi?id=763513

3 files changed, 13 insertions, 22 deletions

diff --git a/src/nm-core-utils.c b/src/nm-core-utils.c
index 52db9ced8e..0c557689fa 100644
--- a/src/nm-core-utils.c
+++ b/src/nm-core-utils.c
@@ -2976,8 +2976,7 @@ nm_utils_ip4_address_is_link_local (in_addr_t addr)
 guint32
 nm_utils_lifetime_rebase_relative_time_on_now (guint32 timestamp,
                                                guint32 duration,
-                                               guint32 now,
-                                               guint32 padding)
+                                               guint32 now)
 {
 	gint64 t;
 
@@ -2998,9 +2997,6 @@ nm_utils_lifetime_rebase_relative_time_on_now (guint32 timestamp,
 	/* For timestamp > now, just accept it and calculate the expected(?) result. */
 	t = (gint64) timestamp + (gint64) duration - (gint64) now;
 
-	/* Optional padding to avoid potential races. */
-	t += (gint64) padding;
-
 	if (t <= 0)
 		return 0;
 	if (t >= NM_PLATFORM_LIFETIME_PERMANENT)
@@ -3013,7 +3009,6 @@ nm_utils_lifetime_get (guint32 timestamp,
                        guint32 lifetime,
                        guint32 preferred,
                        guint32 now,
-                       guint32 padding,
                        guint32 *out_lifetime,
                        guint32 *out_preferred)
 {
@@ -3030,13 +3025,13 @@ nm_utils_lifetime_get (guint32 timestamp,
 	} else {
 		if (!now)
 			now = nm_utils_get_monotonic_timestamp_s ();
-		t_lifetime = nm_utils_lifetime_rebase_relative_time_on_now (timestamp, lifetime, now, padding);
+		t_lifetime = nm_utils_lifetime_rebase_relative_time_on_now (timestamp, lifetime, now);
 		if (!t_lifetime) {
 			*out_lifetime = 0;
 			*out_preferred = 0;
 			return FALSE;
 		}
-		t_preferred = nm_utils_lifetime_rebase_relative_time_on_now (timestamp, preferred, now, padding);
+		t_preferred = nm_utils_lifetime_rebase_relative_time_on_now (timestamp, preferred, now);
 
 		*out_lifetime = t_lifetime;
 		*out_preferred = MIN (t_preferred, t_lifetime);
diff --git a/src/nm-core-utils.h b/src/nm-core-utils.h
index 7e1fdec470..15bc9014aa 100644
--- a/src/nm-core-utils.h
+++ b/src/nm-core-utils.h
@@ -402,14 +402,12 @@ void nm_utils_ifname_cpy (char *dst, const char *name);
 
 guint32 nm_utils_lifetime_rebase_relative_time_on_now (guint32 timestamp,
                                                        guint32 duration,
-                                                       guint32 now,
-                                                       guint32 padding);
+                                                       guint32 now);
 
 gboolean nm_utils_lifetime_get (guint32 timestamp,
                                 guint32 lifetime,
                                 guint32 preferred,
                                 guint32 now,
-                                guint32 padding,
                                 guint32 *out_lifetime,
                                 guint32 *out_preferred);
 
diff --git a/src/platform/nm-platform.c b/src/platform/nm-platform.c
index 89f385ec96..6cc7e1e18f 100644
--- a/src/platform/nm-platform.c
+++ b/src/platform/nm-platform.c
@@ -49,8 +49,6 @@ const NMIPAddr nm_ip_addr_zero = NMIPAddrInit;
 
 /*****************************************************************************/
 
-#define ADDRESS_LIFETIME_PADDING 5
-
 G_STATIC_ASSERT (sizeof ( ((NMPlatformLink *) NULL)->addr.data ) == NM_UTILS_HWADDR_LEN_MAX);
 G_STATIC_ASSERT (G_STRUCT_OFFSET (NMPlatformIPAddress, address_ptr) == G_STRUCT_OFFSET (NMPlatformIP4Address, address));
 G_STATIC_ASSERT (G_STRUCT_OFFSET (NMPlatformIPAddress, address_ptr) == G_STRUCT_OFFSET (NMPlatformIP6Address, address));
@@ -2615,7 +2613,7 @@ nm_platform_ip6_address_get (NMPlatform *self, int ifindex, struct in6_addr addr
 }
 
 static gboolean
-array_contains_ip4_address (const GArray *addresses, const NMPlatformIP4Address *address, gint64 now, guint32 padding)
+array_contains_ip4_address (const GArray *addresses, const NMPlatformIP4Address *address, gint64 now)
 {
 	guint len = addresses ? addresses->len : 0;
 	guint i;
@@ -2629,7 +2627,7 @@ array_contains_ip4_address (const GArray *addresses, const NMPlatformIP4Address
 			guint32 lifetime, preferred;
 
 			if (nm_utils_lifetime_get (candidate->timestamp, candidate->lifetime, candidate->preferred,
-			                           now, padding, &lifetime, &preferred))
+			                           now, &lifetime, &preferred))
 				return TRUE;
 		}
 	}
@@ -2638,7 +2636,7 @@ array_contains_ip4_address (const GArray *addresses, const NMPlatformIP4Address
 }
 
 static gboolean
-array_contains_ip6_address (const GArray *addresses, const NMPlatformIP6Address *address, gint64 now, guint32 padding)
+array_contains_ip6_address (const GArray *addresses, const NMPlatformIP6Address *address, gint64 now)
 {
 	guint len = addresses ? addresses->len : 0;
 	guint i;
@@ -2650,7 +2648,7 @@ array_contains_ip6_address (const GArray *addresses, const NMPlatformIP6Address
 			guint32 lifetime, preferred;
 
 			if (nm_utils_lifetime_get (candidate->timestamp, candidate->lifetime, candidate->preferred,
-			                           now, padding, &lifetime, &preferred))
+			                           now, &lifetime, &preferred))
 				return TRUE;
 		}
 	}
@@ -2689,7 +2687,7 @@ nm_platform_ip4_address_sync (NMPlatform *self, int ifindex, const GArray *known
 	for (i = 0; i < addresses->len; i++) {
 		address = &g_array_index (addresses, NMPlatformIP4Address, i);
 
-		if (!array_contains_ip4_address (known_addresses, address, now, ADDRESS_LIFETIME_PADDING))
+		if (!array_contains_ip4_address (known_addresses, address, now))
 			nm_platform_ip4_address_delete (self, ifindex, address->address, address->plen, address->peer_address);
 	}
 	g_array_free (addresses, TRUE);
@@ -2706,7 +2704,7 @@ nm_platform_ip4_address_sync (NMPlatform *self, int ifindex, const GArray *known
 		guint32 lifetime, preferred;
 
 		if (!nm_utils_lifetime_get (known_address->timestamp, known_address->lifetime, known_address->preferred,
-		                            now, ADDRESS_LIFETIME_PADDING, &lifetime, &preferred))
+		                            now, &lifetime, &preferred))
 			continue;
 
 		if (!nm_platform_ip4_address_add (self, ifindex, known_address->address, known_address->plen,
@@ -2754,7 +2752,7 @@ nm_platform_ip6_address_sync (NMPlatform *self, int ifindex, const GArray *known
 		if (keep_link_local && IN6_IS_ADDR_LINKLOCAL (&address->address))
 			continue;
 
-		if (!array_contains_ip6_address (known_addresses, address, now, ADDRESS_LIFETIME_PADDING))
+		if (!array_contains_ip6_address (known_addresses, address, now))
 			nm_platform_ip6_address_delete (self, ifindex, address->address, address->plen);
 	}
 	g_array_free (addresses, TRUE);
@@ -2768,7 +2766,7 @@ nm_platform_ip6_address_sync (NMPlatform *self, int ifindex, const GArray *known
 		guint32 lifetime, preferred;
 
 		if (!nm_utils_lifetime_get (known_address->timestamp, known_address->lifetime, known_address->preferred,
-		                            now, ADDRESS_LIFETIME_PADDING, &lifetime, &preferred))
+		                            now, &lifetime, &preferred))
 			continue;
 
 		if (!nm_platform_ip6_address_add (self, ifindex, known_address->address,
@@ -3012,7 +3010,7 @@ _lifetime_to_string (guint32 timestamp, guint32 lifetime, gint32 now, char *buf,
 		return "forever";
 
 	g_snprintf (buf, buf_size, "%usec",
-	            nm_utils_lifetime_rebase_relative_time_on_now (timestamp, lifetime, now, 0));
+	            nm_utils_lifetime_rebase_relative_time_on_now (timestamp, lifetime, now));
 	return buf;
 }