Merge remote-tracking branch 'smcv/protocol-addressing'

Reviewed-by: Andre Moreira Magalhaes (andrunko) <andre.magalhaes@collabora.co.uk>

3 files changed, 101 insertions, 21 deletions

diff --git a/spec/spec/Channel_Interface_Tube.xml b/spec/spec/Channel_Interface_Tube.xml
index 858a15dd9..f31ab2138 100644
--- a/spec/spec/Channel_Interface_Tube.xml
+++ b/spec/spec/Channel_Interface_Tube.xml
@@ -204,15 +204,24 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
       array-name="Socket_Access_Control_List">
       <tp:enumvalue suffix="Localhost" value="0">
         <tp:docstring>
-          The IP or Unix socket can be accessed by any local user (e.g.
-          a Unix socket that accepts all local connections, or an IP socket
-          listening on 127.0.0.1 (or ::1) or rejecting connections not from
-          that address). The associated variant must be ignored.
+          <p>The IP or Unix socket can be accessed by any local user (e.g.
+            a Unix socket that accepts all local connections, or an IP socket
+            listening on 127.0.0.1 (or ::1) or rejecting connections not from
+            that address). The associated variant must be ignored.</p>
+
+          <p>For a D-Bus tube, this means that the "same user" access
+            control typically provided by default in D-Bus implementations
+            SHOULD be disabled. If the socket is only available to local users
+            (e.g. a Unix socket, an IPv4 socket bound to 127.0.0.1, or an
+            IPv6 socket bound to ::1), the <code>ANONYMOUS</code>
+            authentication mechanism MAY be enabled.</p>
         </tp:docstring>
       </tp:enumvalue>
       <tp:enumvalue suffix="Port" value="1">
         <tp:docstring>
-          May only be used on IP sockets. The associated variant must contain
+          May only be used on IP sockets, and only for Stream tubes.
+          <!-- ... and maybe Datagram tubes, one day... -->
+          The associated variant must contain
           a struct Socket_Address_IPv4 (or Socket_Address_IPv6)
           containing the string form of an IP address of the appropriate
           version, and a port number. The socket can only be accessed if the
@@ -235,19 +244,41 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
       </tp:enumvalue>
       <tp:enumvalue suffix="Credentials" value="3">
         <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
-          <p>May only be used on UNIX sockets.
+          <p>The high-level meaning of this access control type is that
+            only the same user (e.g. same numeric Unix uid) is allowed to
+            interact with the tube. Exactly how this is achieved varies by
+            channel type.</p>
+
+          <p>For <tp:dbus-ref namespace="org.freedesktop.Telepathy.Channel.Type"
+              >StreamTube</tp:dbus-ref> channels, this access control type
+            may only be used on UNIX sockets.
             The connecting process must send a byte when
             it first connects, which is not considered to be part of the data
             stream. If the operating system uses sendmsg() with SCM_CREDS or
             SCM_CREDENTIALS to pass credentials over sockets, the connecting
             process must do so if possible; if not, it must still send the
-            byte.</p>
+            byte, without any attached credentials. (This mechanism is
+            very similar to the first byte of a D-Bus connection, except that
+            in D-Bus the byte is always zero, whereas in Tubes it can be
+            nonzero.)</p>
+
+          <p>For <tp:dbus-ref namespace="org.freedesktop.Telepathy.Channel.Type"
+              >DBusTube</tp:dbus-ref> channels, this access control type
+            may be used on any type of socket, and there is no extra byte
+            added by Telepathy at the beginning of the stream: all bytes in
+            the stream are part of the D-Bus tube connection. The connecting
+            process should prove its identity via any of the SASL
+            authentication mechanisms usually used for D-Bus (in typical
+            D-Bus implementations this involves either sending and receiving
+            credentials as above, or demonstrating the ability to write to a
+            file in the user's home directory).</p>
 
-          <p>The listening process will disconnect the connection unless it
-            can determine by OS-specific means that the connecting process
-            has the same user ID as the listening process.</p>
+          <p>In either case, the listening process will disconnect the
+            connection unless it can determine by OS-specific means that
+            the connecting process has the same user ID as the listening
+            process.</p>
 
-          <p>The associated variant must be ignored.</p>
+          <p>In either tube type, the associated variant must be ignored.</p>
         </tp:docstring>
       </tp:enumvalue>
     </tp:enum>
diff --git a/spec/spec/Channel_Type_DBus_Tube.xml b/spec/spec/Channel_Type_DBus_Tube.xml
index 961576319..74e659514 100644
--- a/spec/spec/Channel_Type_DBus_Tube.xml
+++ b/spec/spec/Channel_Type_DBus_Tube.xml
@@ -174,7 +174,17 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
       <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
         <p>A list of the access control types that are supported with this channel.
         Note that only Socket_Access_Control_Localhost and
-        Socket_Access_Control_Credentials can be used with D-Bus tubes.</p>
+        Socket_Access_Control_Credentials can be used with D-Bus tubes.
+        Using Socket_Access_Control_Credentials is recommended.</p>
+
+        <tp:rationale>
+          <p>Socket_Access_Control_Credentials is easy to implement for a
+            D-Bus tube, because typical D-Bus library implementations like
+            libdbus and GDBus already have to support it to be able to
+            connect to the system or session bus, and usually enable it
+            by default; so there's typically no good reason to relax
+            access control to Localhost.</p>
+        </tp:rationale>
 
         <p>When requesting a channel with
           <tp:dbus-ref namespace="org.freedesktop.Telepathy">Connection.Interface.Requests.CreateChannel</tp:dbus-ref>,
diff --git a/spec/spec/Protocol_Interface_Addressing.xml b/spec/spec/Protocol_Interface_Addressing.xml
index 3722c3b81..ad406c8df 100644
--- a/spec/spec/Protocol_Interface_Addressing.xml
+++ b/spec/spec/Protocol_Interface_Addressing.xml
@@ -24,6 +24,7 @@
      name="org.freedesktop.Telepathy.Protocol.Interface.Addressing.DRAFT"
      tp:causes-havoc="experimental">
     <tp:added version="0.19.12">(as draft)</tp:added>
+    <tp:changed version="0.25.UNRELEASED">(renamed NormalizeURI)</tp:changed>
     <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
       <p>An interface for protocols that support multiple forms of
         addressing contacts, for example through vCard addresses and URIs.</p>
@@ -217,7 +218,8 @@ AddressableURISchemes=tel;sip;
 
       <arg direction="in" name="VCard_Address" type="s">
         <tp:docstring>
-          The address to normalize.
+          The address to normalize, which is assumed to belong to a
+          contact (and not, for instance, a chatroom or server).
         </tp:docstring>
       </arg>
 
@@ -243,8 +245,9 @@ AddressableURISchemes=tel;sip;
       </tp:possible-errors>
     </method>
 
-    <method name="NormalizeURI"
-      tp:name-for-bindings="Normalize_URI">
+    <method name="NormalizeContactURI"
+      tp:name-for-bindings="Normalize_Contact_URI">
+      <tp:added version="0.25.UNRELEASED">(renamed from NormalizeURI)</tp:added>
       <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
         <p>Attempt to normalize the given contact URI. Where possible, this
           SHOULD return an address that would appear in the
@@ -258,8 +261,28 @@ AddressableURISchemes=tel;sip;
             namespace="org.freedesktop.Telepathy">Connection</tp:dbus-ref>,
           this method SHOULD perform a best-effort normalization.</p>
 
-        <p>Example: <code>xmpp:eitan@EXAMPLE.COM</code> would be normalized to
-        <code>xmpp:eitan@example.com</code>.</p>
+        <p>If the URI has extra information beyond what's necessary to
+          identify a particular contact, such as an XMPP resource or an
+          action to carry out, this extra information SHOULD be removed.
+          If all URIs in a scheme contain a verb or action
+          (like <code>aim</code>, <code>ymsgr</code> and
+          <code>msnim</code> URIs), then the verb SHOULD be replaced
+          with the one specified in
+          <tp:member-ref>AddressableURISchemes</tp:member-ref>.</p>
+
+        <tp:rationale>
+          <p>This method is intended to normalize URIs stored in address
+            books, for instance. In protocols like XMPP, if you
+            vary the resource or action (query string), the URI still
+            refers to the same high-level contact.</p>
+        </tp:rationale>
+
+        <p>For instance,
+          <code>xmpp:romeo@Example.Com/Empathy?message;body=Hello</code>
+          would be normalized to <code>xmpp:romeo@example.com</code>,
+          and <code>aim:goim?screenname=Romeo%20M&amp;message=Hello</code>
+          would be normalized to
+          <code>aim:addbuddy?screenname=romeom</code>.</p>
 
         <p>This method MAY simply raise NotImplemented on some
         protocols, if it has no use.</p>
@@ -267,9 +290,18 @@ AddressableURISchemes=tel;sip;
 
       <arg direction="in" name="URI" type="s">
         <tp:docstring>
-          The URI to normalize. The URI's scheme (i.e. the part before
-          the first colon) MUST appear in
-          <tp:member-ref>AddressableURISchemes</tp:member-ref>.
+          <p>The URI to normalize, which is assumed to refer to a contact
+            (as opposed to, for instance, a chatroom or a server).</p>
+
+        <tp:rationale>
+          <p>In some protocols, like XMPP, there is no way to tell whether
+            a given URI refers to a contact or a chatroom by looking at
+            its syntax.</p>
+        </tp:rationale>
+
+          <p>The URI's scheme (i.e. the part before
+            the first colon) MUST appear in
+            <tp:member-ref>AddressableURISchemes</tp:member-ref>.</p>
         </tp:docstring>
       </arg>
 
@@ -289,7 +321,14 @@ AddressableURISchemes=tel;sip;
 
         <tp:error name="org.freedesktop.Telepathy.Error.InvalidArgument">
           <tp:docstring>
-            The URI is syntactically incorrect.
+            <p>The URI is syntactically incorrect or cannot be interpreted
+              as a reference to a contact.</p>
+
+            <tp:rationale>
+              <p>For instance, <code>aim:!?</code> is not a valid AIM URI,
+                while <code>aim:goaway?message=Absent</code> is a
+                valid AIM URI, but not a contact.</p>
+            </tp:rationale>
           </tp:docstring>
         </tp:error>
       </tp:possible-errors>