platform: properly handle IPv4 peer-addresses

The peer-address (IFA_ADDRESS) can also be all-zero (0.0.0.0).
That is distinct from an usual address without explicit peer-address,
which implicitly has the same peer and local address.

Previously, we treated an all-zero peer_address as having peer and
local address equal. This is especially grave, because the peer is part
of the primary key for an IPv4 address. So we not only get a property of
the address wrong, but we wrongly consider two different addresses as
one and the same.

To properly handle these addresses, we always must explicitly set the peer.

5 files changed, 10 insertions, 6 deletions

diff --git a/src/dhcp-manager/nm-dhcp-dhclient-utils.c b/src/dhcp-manager/nm-dhcp-dhclient-utils.c
index a86596c077..726d26c8d0 100644
--- a/src/dhcp-manager/nm-dhcp-dhclient-utils.c
+++ b/src/dhcp-manager/nm-dhcp-dhclient-utils.c
@@ -675,6 +675,7 @@ nm_dhcp_dhclient_read_lease_ip_configs (const char *iface,
 			continue;
 		if (!inet_pton (AF_INET, value, &address.address))
 			continue;
+		address.peer_address = address.address;
 
 		/* Gateway */
 		value = g_hash_table_lookup (hash, "option routers");
diff --git a/src/dhcp-manager/nm-dhcp-systemd.c b/src/dhcp-manager/nm-dhcp-systemd.c
index 4459fd583f..e508ea13bb 100644
--- a/src/dhcp-manager/nm-dhcp-systemd.c
+++ b/src/dhcp-manager/nm-dhcp-systemd.c
@@ -232,6 +232,7 @@ lease_to_ip4_config (const char *iface,
 	sd_dhcp_lease_get_address (lease, &tmp_addr);
 	memset (&address, 0, sizeof (address));
 	address.address = tmp_addr.s_addr;
+	address.peer_address = tmp_addr.s_addr;
 	str = nm_utils_inet4_ntop (tmp_addr.s_addr, NULL);
 	LOG_LEASE (LOGD_DHCP4, "  address %s", str);
 	add_option (options, dhcp4_requests, DHCP_OPTION_IP_ADDRESS, str);
diff --git a/src/dhcp-manager/nm-dhcp-utils.c b/src/dhcp-manager/nm-dhcp-utils.c
index c7c246a7ce..e6bc18072c 100644
--- a/src/dhcp-manager/nm-dhcp-utils.c
+++ b/src/dhcp-manager/nm-dhcp-utils.c
@@ -380,6 +380,7 @@ nm_dhcp_utils_ip4_config_from_options (int ifindex,
 {
 	NMIP4Config *ip4_config = NULL;
 	guint32 tmp_addr;
+	in_addr_t addr;
 	NMPlatformIP4Address address;
 	char *str = NULL;
 	guint32 gwaddr = 0, plen = 0;
@@ -391,10 +392,9 @@ nm_dhcp_utils_ip4_config_from_options (int ifindex,
 	address.timestamp = nm_utils_get_monotonic_timestamp_s ();
 
 	str = g_hash_table_lookup (options, "ip_address");
-	if (str && (inet_pton (AF_INET, str, &tmp_addr) > 0)) {
-		address.address = tmp_addr;
+	if (str && (inet_pton (AF_INET, str, &addr) > 0))
 		nm_log_info (LOGD_DHCP4, "  address %s", str);
-	} else
+	else
 		goto error;
 
 	str = g_hash_table_lookup (options, "subnet_mask");
@@ -403,10 +403,10 @@ nm_dhcp_utils_ip4_config_from_options (int ifindex,
 		nm_log_info (LOGD_DHCP4, "  plen %d (%s)", plen, str);
 	} else {
 		/* Get default netmask for the IP according to appropriate class. */
-		plen = nm_utils_ip4_get_default_prefix (address.address);
+		plen = nm_utils_ip4_get_default_prefix (addr);
 		nm_log_info (LOGD_DHCP4, "  plen %d (default)", plen);
 	}
-	address.plen = plen;
+	nm_platform_ip4_address_set_addr (&address, addr, plen);
 
 	/* Routes: if the server returns classless static routes, we MUST ignore
 	 * the 'static_routes' option.
diff --git a/src/dhcp-manager/tests/test-dhcp-dhclient.c b/src/dhcp-manager/tests/test-dhcp-dhclient.c
index 15817addb4..ce3697a552 100644
--- a/src/dhcp-manager/tests/test-dhcp-dhclient.c
+++ b/src/dhcp-manager/tests/test-dhcp-dhclient.c
@@ -666,6 +666,7 @@ test_read_lease_ip4_config_basic (void)
 	g_assert (inet_aton ("192.168.1.180", (struct in_addr *) &expected_addr));
 	addr = nm_ip4_config_get_address (config, 0);
 	g_assert_cmpint (addr->address, ==, expected_addr);
+	g_assert_cmpint (addr->peer_address, ==, expected_addr);
 	g_assert_cmpint (addr->plen, ==, 24);
 
 	/* Gateway */
@@ -688,6 +689,7 @@ test_read_lease_ip4_config_basic (void)
 	g_assert (inet_aton ("10.77.52.141", (struct in_addr *) &expected_addr));
 	addr = nm_ip4_config_get_address (config, 0);
 	g_assert_cmpint (addr->address, ==, expected_addr);
+	g_assert_cmpint (addr->peer_address, ==, expected_addr);
 	g_assert_cmpint (addr->plen, ==, 8);
 
 	/* Gateway */
diff --git a/src/dhcp-manager/tests/test-dhcp-utils.c b/src/dhcp-manager/tests/test-dhcp-utils.c
index 65a396092a..49987c40ca 100644
--- a/src/dhcp-manager/tests/test-dhcp-utils.c
+++ b/src/dhcp-manager/tests/test-dhcp-utils.c
@@ -95,7 +95,7 @@ test_generic_options (void)
 	address = nm_ip4_config_get_address (ip4_config, 0);
 	g_assert (inet_pton (AF_INET, expected_addr, &tmp) > 0);
 	g_assert (address->address == tmp);
-	g_assert (address->peer_address == 0);
+	g_assert (address->peer_address == tmp);
 	g_assert_cmpint (address->plen, ==, 24);
 
 	/* Gateway */