all: add stable-id specifier "${DEVICE}"

Add new stable-id specifier "${DEVICE}" to explicitly declare that the
connection's identity differs per-device.

Note that for settings like "ipv6.addr-gen-mode=stable" we already hash
the interface's name. So, in combination with addr-gen-mode, using this
specifier has no real use. But for example, we don't do that for
"ipv4.dhcp-client-id=stable".
Point being, in various context we possibly already include a per-device
token into the generation algorithm. But that is not the case for all
contexts and uses.

Especially the DHCPv4 client identifier is supposed to differ between interfaces
(according to RFC). We don't do that by default with "ipv4.dhcp-client-id=stable",
but with "${DEVICE}" can can now be configured by the user.
Note that the fact that the client-id is the same accross interfaces, is not a
common problem, because profiles are usually restricted to one device via
connection.interface-name.

6 files changed, 30 insertions, 20 deletions

diff --git a/clients/common/settings-docs.h.in b/clients/common/settings-docs.h.in
index 2896158157..06f96a4e1f 100644
--- a/clients/common/settings-docs.h.in
+++ b/clients/common/settings-docs.h.in
@@ -152,7 +152,7 @@
 #define DESCRIBE_DOC_NM_SETTING_CONNECTION_READ_ONLY N_("FALSE if the connection can be modified using the provided settings service's D-Bus interface with the right privileges, or TRUE if the connection is read-only and cannot be modified.")
 #define DESCRIBE_DOC_NM_SETTING_CONNECTION_SECONDARIES N_("List of connection UUIDs that should be activated when the base connection itself is activated. Currently only VPN connections are supported.")
 #define DESCRIBE_DOC_NM_SETTING_CONNECTION_SLAVE_TYPE N_("Setting name of the device type of this slave's master connection (eg, \"bond\"), or NULL if this connection is not a slave.")
-#define DESCRIBE_DOC_NM_SETTING_CONNECTION_STABLE_ID N_("Token to generate stable IDs for the connection. The stable-id is used for generating IPv6 stable private addresses with ipv6.addr-gen-mode=stable-privacy. It is also used to seed the generated cloned MAC address for ethernet.cloned-mac-address=stable and wifi.cloned-mac-address=stable. It is also used as DHCP client identifier with ipv4.dhcp-client-id=stable. Note that also the interface name of the activating connection and a per-host secret key is included into the address generation so that the same stable-id on different hosts/devices yields different addresses. If the value is unset, an ID unique for the connection is used. Specifying a stable-id allows multiple connections to generate the same addresses. Another use is to generate IDs at runtime via dynamic substitutions. The '$' character is treated special to perform dynamic substitutions at runtime. Currently supported are \"${CONNECTION}\", \"${BOOT}\", \"${RANDOM}\". These effectively create unique IDs per-connection, per-boot, or every time. Any unrecognized patterns following '$' are treated verbatim, however are reserved for future use. You are thus advised to avoid '$' or escape it as \"$$\". For example, set it to \"${CONNECTION}/${BOOT}\" to create a unique id for this connection that changes with every reboot. Note that two connections only use the same effective id if their stable-id is also identical before performing dynamic substitutions.")
+#define DESCRIBE_DOC_NM_SETTING_CONNECTION_STABLE_ID N_("This represents the identity of the connection used for various purposes. It allows to configure multiple profiles to share the identity. Also, the stable-id can contain placeholders that are substituted dynamically and deterministically depending on the context. The stable-id is used for generating IPv6 stable private addresses with ipv6.addr-gen-mode=stable-privacy. It is also used to seed the generated cloned MAC address for ethernet.cloned-mac-address=stable and wifi.cloned-mac-address=stable. It is also used as DHCP client identifier with ipv4.dhcp-client-id=stable. Note that depending on the context where it is used, other parameters are also seeded into the generation algorithm. For example, a per-host key is commonly also included, so that different systems end up generating different IDs. Or with ipv6.addr-gen-mode=stable-privacy, also the device's name is included, so that different interfaces yield different addresses. The '$' character is treated special to perform dynamic substitutions at runtime. Currently supported are \"${CONNECTION}\", \"${DEVICE}\", \"${BOOT}\", \"${RANDOM}\". These effectively create unique IDs per-connection, per-device, per-boot, or every time. Note that \"${DEVICE}\" corresponds the the interface name of the device. Any unrecognized patterns following '$' are treated verbatim, however are reserved for future use. You are thus advised to avoid '$' or escape it as \"$$\". For example, set it to \"${CONNECTION}-${BOOT}-${DEVICE}\" to create a unique id for this connection that changes with every reboot and differs depending on the interface where the profile activates. If the value is unset, a global connection default is consulted. If the value is still unset, the default is similar to \"${CONNECTION}\" and uses a unique, fixed ID for the connection.")
 #define DESCRIBE_DOC_NM_SETTING_CONNECTION_TIMESTAMP N_("The time, in seconds since the Unix Epoch, that the connection was last _successfully_ fully activated. NetworkManager updates the connection timestamp periodically when the connection is active to ensure that an active connection has the latest timestamp. The property is only meant for reading (changes to this property will not be preserved).")
 #define DESCRIBE_DOC_NM_SETTING_CONNECTION_TYPE N_("Base type of the connection. For hardware-dependent connections, should contain the setting name of the hardware-type specific setting (ie, \"802-3-ethernet\" or \"802-11-wireless\" or \"bluetooth\", etc), and for non-hardware dependent connections like VPN or otherwise, should contain the setting name of that setting type (ie, \"vpn\" or \"bridge\", etc).")
 #define DESCRIBE_DOC_NM_SETTING_CONNECTION_UUID N_("A universally unique identifier for the connection, for example generated with libuuid.  It should be assigned when the connection is created, and never changed as long as the connection still applies to the same network.  For example, it should not be changed when the \"id\" property or NMSettingIP4Config changes, but might need to be re-created when the Wi-Fi SSID, mobile broadband network provider, or \"type\" property changes. The UUID must be in the format \"2815492f-7e56-435e-b2e9-246bd7cdc664\" (ie, contains only hexadecimal characters and \"-\").")
diff --git a/libnm-core/nm-setting-connection.c b/libnm-core/nm-setting-connection.c
index 8e6cb87c6e..f8f1b017e6 100644
--- a/libnm-core/nm-setting-connection.c
+++ b/libnm-core/nm-setting-connection.c
@@ -1535,7 +1535,10 @@ nm_setting_connection_class_init (NMSettingConnectionClass *setting_class)
 	/**
 	 * NMSettingConnection:stable-id:
 	 *
-	 * Token to generate stable IDs for the connection.
+	 * This represents the identity of the connection used for various purposes.
+	 * It allows to configure multiple profiles to share the identity. Also,
+	 * the stable-id can contain placeholders that are substituted dynamically and
+	 * deterministically depending on the context.
 	 *
 	 * The stable-id is used for generating IPv6 stable private addresses
 	 * with ipv6.addr-gen-mode=stable-privacy. It is also used to seed the
@@ -1543,26 +1546,28 @@ nm_setting_connection_class_init (NMSettingConnectionClass *setting_class)
 	 * and wifi.cloned-mac-address=stable. It is also used as DHCP client
 	 * identifier with ipv4.dhcp-client-id=stable.
 	 *
-	 * Note that also the interface name of the activating connection and a
-	 * per-host secret key is included into the address generation so that the
-	 * same stable-id on different hosts/devices yields different addresses.
-	 *
-	 * If the value is unset, an ID unique for the connection is used.
-	 * Specifying a stable-id allows multiple connections to generate the
-	 * same addresses. Another use is to generate IDs at runtime via
-	 * dynamic substitutions.
+	 * Note that depending on the context where it is used, other parameters are
+	 * also seeded into the generation algorithm. For example, a per-host key
+	 * is commonly also included, so that different systems end up generating
+	 * different IDs. Or with ipv6.addr-gen-mode=stable-privacy, also the device's
+	 * name is included, so that different interfaces yield different addresses.
 	 *
 	 * The '$' character is treated special to perform dynamic substitutions
-	 * at runtime. Currently supported are "${CONNECTION}", "${BOOT}", "${RANDOM}".
-	 * These effectively create unique IDs per-connection, per-boot, or every time.
+	 * at runtime. Currently supported are "${CONNECTION}", "${DEVICE}",
+	 * "${BOOT}", "${RANDOM}".
+	 * These effectively create unique IDs per-connection, per-device, per-boot,
+	 * or every time. Note that "${DEVICE}" corresponds the the interface name of the
+	 * device.
 	 * Any unrecognized patterns following '$' are treated verbatim, however
 	 * are reserved for future use. You are thus advised to avoid '$' or
 	 * escape it as "$$".
-	 * For example, set it to "${CONNECTION}/${BOOT}" to create a unique id for
-	 * this connection that changes with every reboot.
+	 * For example, set it to "${CONNECTION}-${BOOT}-${DEVICE}" to create a unique id for
+	 * this connection that changes with every reboot and differs depending on the
+	 * interface where the profile activates.
 	 *
-	 * Note that two connections only use the same effective id if
-	 * their stable-id is also identical before performing dynamic substitutions.
+	 * If the value is unset, a global connection default is consulted. If the
+	 * value is still unset, the default is similar to "${CONNECTION}" and uses
+	 * a unique, fixed ID for the connection.
 	 *
 	 * Since: 1.4
 	 **/
diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index d26f23d0a0..d133452b87 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -1177,8 +1177,9 @@ _get_stable_id (NMDevice *self,
 		uuid = nm_connection_get_uuid (connection);
 
 		stable_type = nm_utils_stable_id_parse (stable_id,
-		                                        uuid,
+		                                        nm_device_get_ip_iface (self),
 		                                        NULL,
+		                                        uuid,
 		                                        &generated);
 
 		/* current_stable_id_type is a bitfield! */
diff --git a/src/nm-core-utils.c b/src/nm-core-utils.c
index 50df2b5c2e..b1a4cc25a2 100644
--- a/src/nm-core-utils.c
+++ b/src/nm-core-utils.c
@@ -3181,8 +3181,9 @@ _stable_id_append (GString *str,
 
 NMUtilsStableType
 nm_utils_stable_id_parse (const char *stable_id,
-                          const char *uuid,
+                          const char *deviceid,
                           const char *bootid,
+                          const char *uuid,
                           char **out_generated)
 {
 	gsize i, idx_start;
@@ -3257,6 +3258,8 @@ nm_utils_stable_id_parse (const char *stable_id,
 			_stable_id_append (str, uuid);
 		else if (CHECK_PREFIX ("${BOOT}"))
 			_stable_id_append (str, bootid ?: nm_utils_get_boot_id ());
+		else if (CHECK_PREFIX ("${DEVICE}"))
+			_stable_id_append (str, deviceid);
 		else if (g_str_has_prefix (&stable_id[i], "${RANDOM}")) {
 			/* RANDOM makes not so much sense for cloned-mac-address
 			 * as the result is simmilar to specyifing "cloned-mac-address=random".
diff --git a/src/nm-core-utils.h b/src/nm-core-utils.h
index ed66a7f0c8..7f406d214c 100644
--- a/src/nm-core-utils.h
+++ b/src/nm-core-utils.h
@@ -340,8 +340,9 @@ typedef enum {
 } NMUtilsStableType;
 
 NMUtilsStableType nm_utils_stable_id_parse (const char *stable_id,
-                                            const char *uuid,
+                                            const char *deviceid,
                                             const char *bootid,
+                                            const char *uuid,
                                             char **out_generated);
 
 char *nm_utils_stable_id_random (void);
diff --git a/src/tests/test-general.c b/src/tests/test-general.c
index 0d500c62e2..4db05ac847 100644
--- a/src/tests/test-general.c
+++ b/src/tests/test-general.c
@@ -1621,7 +1621,7 @@ do_test_stable_id_parse (const char *stable_id,
 	else
 		g_assert (stable_id);
 
-	stable_type = nm_utils_stable_id_parse (stable_id, "_CONNECTION", "_BOOT", &generated);
+	stable_type = nm_utils_stable_id_parse (stable_id, "_DEVICE", "_BOOT", "_CONNECTION", &generated);
 
 	g_assert_cmpint (expected_stable_type, ==, stable_type);