2005-02-25 Havoc Pennington <hp@redhat.com>

	* doc/dbus-specification.xml: document the GUID thing

	* dbus/dbus-server.c (_dbus_server_init_base): initialize a
	globally unique ID for the server, and put a "guid=hexencoded"
	field in the address

	* dbus/dbus-bus.c: fix missing #include of dbus-threads-internal.h

	* dbus/dbus-message.c: ditto

	* dbus/dbus-dataslot.c: ditto

	* dbus/dbus-list.c: ditto

	* dbus/dbus-internals.h: wait, just include
	dbus-threads-internal.h here

	* dbus/dbus-string.c (_dbus_string_copy_to_buffer): move back for
	use in main library

	* dbus/dbus-sysdeps.c (_dbus_generate_random_bytes_buffer): new function

13 files changed, 204 insertions, 48 deletions

diff --git a/ChangeLog b/ChangeLog
index 759355e7..0f8daf25 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,27 @@
+2005-02-25  Havoc Pennington  <hp@redhat.com>
+
+	* doc/dbus-specification.xml: document the GUID thing
+
+	* dbus/dbus-server.c (_dbus_server_init_base): initialize a
+	globally unique ID for the server, and put a "guid=hexencoded"
+	field in the address
+
+	* dbus/dbus-bus.c: fix missing #include of dbus-threads-internal.h
+
+	* dbus/dbus-message.c: ditto
+
+	* dbus/dbus-dataslot.c: ditto
+
+	* dbus/dbus-list.c: ditto
+
+	* dbus/dbus-internals.h: wait, just include
+	dbus-threads-internal.h here
+	
+	* dbus/dbus-string.c (_dbus_string_copy_to_buffer): move back for
+	use in main library
+
+	* dbus/dbus-sysdeps.c (_dbus_generate_random_bytes_buffer): new function
+
 2005-02-24  Colin Walters  <walters@verbum.org>
 
 	* test/glib/Makefile.am (EXTRA_DIST): Add test-service-glib.xml
diff --git a/dbus/dbus-bus.c b/dbus/dbus-bus.c
index 188418c2..fedee0f0 100644
--- a/dbus/dbus-bus.c
+++ b/dbus/dbus-bus.c
@@ -27,6 +27,7 @@
 #include "dbus-internals.h"
 #include "dbus-message.h"
 #include "dbus-marshal-validate.h"
+#include "dbus-threads-internal.h"
 #include <string.h>
 
 /**
diff --git a/dbus/dbus-dataslot.c b/dbus/dbus-dataslot.c
index 8026d048..8a2937de 100644
--- a/dbus/dbus-dataslot.c
+++ b/dbus/dbus-dataslot.c
@@ -21,7 +21,7 @@
  *
  */
 #include "dbus-dataslot.h"
-#include "dbus-threads.h"
+#include "dbus-threads-internal.h"
 
 /**
  * @defgroup DBusDataSlot Data slots
diff --git a/dbus/dbus-internals.h b/dbus/dbus-internals.h
index dcbc6183..b141c23d 100644
--- a/dbus/dbus-internals.h
+++ b/dbus/dbus-internals.h
@@ -33,7 +33,7 @@
 #include <dbus/dbus-types.h>
 #include <dbus/dbus-errors.h>
 #include <dbus/dbus-sysdeps.h>
-#include <dbus/dbus-threads.h>
+#include <dbus/dbus-threads-internal.h>
 
 DBUS_BEGIN_DECLS
 
diff --git a/dbus/dbus-list.c b/dbus/dbus-list.c
index 949e70a8..7389c268 100644
--- a/dbus/dbus-list.c
+++ b/dbus/dbus-list.c
@@ -24,7 +24,7 @@
 #include "dbus-internals.h"
 #include "dbus-list.h"
 #include "dbus-mempool.h"
-#include "dbus-threads.h"
+#include "dbus-threads-internal.h"
 
 /**
  * @defgroup DBusList Linked list
diff --git a/dbus/dbus-message.c b/dbus/dbus-message.c
index 7ff5762c..672a72b4 100644
--- a/dbus/dbus-message.c
+++ b/dbus/dbus-message.c
@@ -32,6 +32,7 @@
 #include "dbus-object-tree.h"
 #include "dbus-memory.h"
 #include "dbus-list.h"
+#include "dbus-threads-internal.h"
 #include <string.h>
 
 /**
diff --git a/dbus/dbus-server-protected.h b/dbus/dbus-server-protected.h
index 284d02c5..dbbc3c62 100644
--- a/dbus/dbus-server-protected.h
+++ b/dbus/dbus-server-protected.h
@@ -35,6 +35,16 @@
 DBUS_BEGIN_DECLS
 
 typedef struct DBusServerVTable DBusServerVTable;
+typedef union DBusGUID DBusGUID;
+
+/**
+ * A server's globally unique ID
+ */
+union DBusGUID
+{
+  dbus_uint32_t as_uint32s[4];
+  unsigned char as_bytes[16];
+};
 
 /**
  * Virtual table to be implemented by all server "subclasses"
@@ -56,6 +66,9 @@ struct DBusServer
   DBusAtomic refcount;                        /**< Reference count. */
   const DBusServerVTable *vtable;             /**< Virtual methods for this instance. */
   DBusMutex *mutex;                           /**< Lock on the server object */
+
+  DBusGUID guid;                              /**< Globally unique ID of server */ 
+  
   DBusWatchList *watches;                     /**< Our watches */
   DBusTimeoutList *timeouts;                  /**< Our timeouts */  
 
diff --git a/dbus/dbus-server.c b/dbus/dbus-server.c
index 156d5ccd..20fb5f3c 100644
--- a/dbus/dbus-server.c
+++ b/dbus/dbus-server.c
@@ -52,6 +52,58 @@
  * @{
  */
 
+static void
+init_guid (DBusGUID *guid)
+{
+  long now;
+  char *p;
+  int ts_size;
+
+  _dbus_get_current_time (&now, NULL);
+
+  guid->as_uint32s[0] = now;
+
+  ts_size = sizeof (guid->as_uint32s[0]);
+  p = ((char*)guid->as_bytes) + ts_size;
+  
+  _dbus_generate_random_bytes_buffer (p,
+                                      sizeof (guid->as_bytes) - ts_size);
+}
+
+/* this is a little fragile since it assumes the address doesn't
+ * already have a guid, but it shouldn't
+ */
+static char*
+copy_address_with_guid_appended (const DBusString *address,
+                                 const DBusGUID   *guid)
+{
+  DBusString with_guid;
+  DBusString guid_str;
+  char *retval;
+  
+  if (!_dbus_string_init (&with_guid))
+    return NULL;
+
+  _dbus_string_init_const_len (&guid_str, guid->as_bytes,
+                               sizeof (guid->as_bytes));
+
+  if (!_dbus_string_copy (address, 0, &with_guid, 0) ||
+      !_dbus_string_append (&with_guid, ",guid=") ||
+      !_dbus_string_hex_encode (&guid_str, 0,
+                                &with_guid, _dbus_string_get_length (&with_guid)))
+    {
+      _dbus_string_free (&with_guid);
+      return NULL;
+    }
+
+  retval = NULL;
+  _dbus_string_copy_data (&with_guid, &retval);
+
+  _dbus_string_free (&with_guid);
+      
+  return retval; /* may be NULL if copy failed */
+}
+
 /**
  * Initializes the members of the DBusServer base class.
  * Chained up to by subclass constructors.
@@ -65,17 +117,21 @@ dbus_bool_t
 _dbus_server_init_base (DBusServer             *server,
                         const DBusServerVTable *vtable,
                         const DBusString       *address)
-{
+{  
   server->vtable = vtable;
   server->refcount.value = 1;
 
   server->address = NULL;
   server->watches = NULL;
   server->timeouts = NULL;
-  
-  if (!_dbus_string_copy_data (address, &server->address))
-    goto failed;
 
+  init_guid (&server->guid);
+
+  server->address = copy_address_with_guid_appended (address,
+                                                     &server->guid);
+  if (server->address == NULL)
+    goto failed;
+  
   server->mutex = _dbus_mutex_new ();
   if (server->mutex == NULL)
     goto failed;
@@ -438,7 +494,9 @@ dbus_server_listen (const char     *address,
   
   for (i = 0; i < len; i++)
     {
-      const char *method = dbus_address_entry_get_method (entries[i]);
+      const char *method;
+
+      method = dbus_address_entry_get_method (entries[i]);
 
       if (strcmp (method, "unix") == 0)
 	{
diff --git a/dbus/dbus-string-util.c b/dbus/dbus-string-util.c
index 0610c66d..ddb9d750 100644
--- a/dbus/dbus-string-util.c
+++ b/dbus/dbus-string-util.c
@@ -32,30 +32,6 @@
  */
 
 /**
- * Copies the contents of a DBusString into a different
- * buffer. The resulting buffer will be nul-terminated.
- * 
- * @param str a string
- * @param buffer a C buffer to copy data to
- * @param avail_len maximum length of C buffer
- */
-void
-_dbus_string_copy_to_buffer (const DBusString  *str,
-			     char              *buffer,
-			     int                avail_len)
-{
-  int copy_len;
-  DBUS_CONST_STRING_PREAMBLE (str);
-
-  _dbus_assert (avail_len >= 0);
-
-  copy_len = MIN (avail_len, real->len+1);
-  memcpy (buffer, real->str, copy_len);
-  if (avail_len > 0 && avail_len == copy_len)
-    buffer[avail_len-1] = '\0';
-}
-
-/**
  * Returns whether a string ends with the given suffix
  *
  * @todo memcmp might make this faster.
diff --git a/dbus/dbus-string.c b/dbus/dbus-string.c
index 5088bca9..86d3eb83 100644
--- a/dbus/dbus-string.c
+++ b/dbus/dbus-string.c
@@ -708,6 +708,30 @@ _dbus_string_copy_data (const DBusString  *str,
   return TRUE;
 }
 
+/**
+ * Copies the contents of a DBusString into a different
+ * buffer. The resulting buffer will be nul-terminated.
+ * 
+ * @param str a string
+ * @param buffer a C buffer to copy data to
+ * @param avail_len maximum length of C buffer
+ */
+void
+_dbus_string_copy_to_buffer (const DBusString  *str,
+			     char              *buffer,
+			     int                avail_len)
+{
+  int copy_len;
+  DBUS_CONST_STRING_PREAMBLE (str);
+
+  _dbus_assert (avail_len >= 0);
+
+  copy_len = MIN (avail_len, real->len+1);
+  memcpy (buffer, real->str, copy_len);
+  if (avail_len > 0 && avail_len == copy_len)
+    buffer[avail_len-1] = '\0';
+}
+
 #ifdef DBUS_BUILD_TESTS
 /**
  * Copies a segment of the string into a char*
diff --git a/dbus/dbus-sysdeps.c b/dbus/dbus-sysdeps.c
index 83c1ce4c..830e26f1 100644
--- a/dbus/dbus-sysdeps.c
+++ b/dbus/dbus-sysdeps.c
@@ -2328,15 +2328,12 @@ _dbus_concat_dir_and_file (DBusString       *dir,
 }
 
 static dbus_bool_t
-pseudorandom_generate_random_bytes (DBusString *str,
-                                    int         n_bytes)
+pseudorandom_generate_random_bytes_buffer (char *buffer,
+                                           int   n_bytes)
 {
-  int old_len;
   unsigned long tv_usec;
   int i;
   
-  old_len = _dbus_string_get_length (str);
-
   /* fall back to pseudorandom */
   _dbus_verbose ("Falling back to pseudorandom for %d bytes\n",
                  n_bytes);
@@ -2352,18 +2349,56 @@ pseudorandom_generate_random_bytes (DBusString *str,
           
       r = rand ();
       b = (r / (double) RAND_MAX) * 255.0;
-          
-      if (!_dbus_string_append_byte (str, b))
-        goto failed;
-          
+
+      buffer[i] = b;
+
       ++i;
     }
+}
+
+static dbus_bool_t
+pseudorandom_generate_random_bytes (DBusString *str,
+                                    int         n_bytes)
+{
+  int old_len;
+  char *p;
+  
+  old_len = _dbus_string_get_length (str);
+
+  if (!_dbus_string_lengthen (str, n_bytes))
+    return FALSE;
+
+  p = _dbus_string_get_data_len (str, old_len, n_bytes);
+
+  pseudorandom_generate_random_bytes_buffer (p, n_bytes);
 
   return TRUE;
+}
 
- failed:
-  _dbus_string_set_length (str, old_len);
-  return FALSE;
+/**
+ * Fills n_bytes of the given buffer with random bytes.
+ *
+ * @param buffer an allocated buffer
+ * @param n_bytes the number of bytes in buffer to write to
+ */
+void
+_dbus_generate_random_bytes_buffer (char *buffer,
+                                    int   n_bytes)
+{
+  DBusString str;
+
+  if (!_dbus_string_init (&str))
+    return pseudorandom_generate_random_bytes_buffer (buffer, n_bytes);
+
+  if (!_dbus_generate_random_bytes (&str, n_bytes))
+    {
+      _dbus_string_free (&str);
+      return pseudorandom_generate_random_bytes_buffer (buffer, n_bytes);
+    }
+
+  _dbus_string_copy_to_buffer (&str, buffer, n_bytes);
+
+  _dbus_string_free (&str);
 }
 
 /**
diff --git a/dbus/dbus-sysdeps.h b/dbus/dbus-sysdeps.h
index dabf334c..6727630a 100644
--- a/dbus/dbus-sysdeps.h
+++ b/dbus/dbus-sysdeps.h
@@ -256,10 +256,12 @@ dbus_bool_t  _dbus_directory_get_next_file (DBusDirIter      *iter,
 void         _dbus_directory_close         (DBusDirIter      *iter);
 
 
-dbus_bool_t _dbus_generate_random_bytes (DBusString *str,
-                                         int         n_bytes);
-dbus_bool_t _dbus_generate_random_ascii (DBusString *str,
-                                         int         n_bytes);
+void        _dbus_generate_random_bytes_buffer (char       *buffer,
+                                                int         n_bytes);
+dbus_bool_t _dbus_generate_random_bytes        (DBusString *str,
+                                                int         n_bytes);
+dbus_bool_t _dbus_generate_random_ascii        (DBusString *str,
+                                                int         n_bytes);
 
 const char *_dbus_errno_to_string  (int errnum);
 const char* _dbus_error_from_errno (int error_number);
diff --git a/doc/dbus-specification.xml b/doc/dbus-specification.xml
index 1d47733c..ff625447 100644
--- a/doc/dbus-specification.xml
+++ b/doc/dbus-specification.xml
@@ -2165,6 +2165,28 @@
       The set of optionally-escaped bytes is intended to preserve address 
       readability and convenience.
     </para>
+
+    <para>
+      A server may specify a key-value pair with the key <literal>guid</literal>
+      and the value a hex-encoded 16-byte sequence. This globally unique ID must
+      be created by filling the first 4 bytes with a 32-bit UNIX time since the
+      epoch, and the remaining 12 bytes with random bytes. If present, the GUID
+      may be used to distinguish one server from another. A server should use a
+      different GUID for each address it listens on. For example, if a message
+      bus daemon offers both UNIX domain socket and TCP connections, but treats
+      clients the same regardless of how they connect, those two connections are
+      equivalent post-connection but should have distinct GUIDs to distinguish
+      the kinds of connection.
+    </para>
+    
+    <para>
+      The intent of the GUID feature is to allow a client to avoid opening
+      multiple identical connections to the same server, by allowing the client
+      to check whether an address corresponds to an already-existing connection.
+      Comparing two addresses is insufficient, because addresses can be recycled
+      by distinct servers.
+    </para>
+
     <para>
       [FIXME clarify if attempting to connect to each is a requirement 
       or just a suggestion]