Temporary fix for the problem that pg_stat_activity, inet_client_addr(),

and inet_server_addr() fail if the client connected over a "scoped" IPv6
address.  In this case getnameinfo() will return a string ending with
a poorly-standardized "%something" zone specifier, which these functions
try to feed to network_in(), which won't take it.  So that we don't lose
functionality altogether, suppress the zone specifier before giving the
string to network_in().  Per report from Brian Hirt.

TODO: probably someday the inet type should support scoped IPv6 addresses,
and then this patch should be reverted.

Backpatch to 8.2 ... is it worth going further?

src/backend/utils/adt/network.c

 /*
  *	PostgreSQL type definitions for the INET and CIDR types.
  *
- *	$PostgreSQL: pgsql/src/backend/utils/adt/network.c,v 1.69 2007/04/06 04:21:43 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/utils/adt/network.c,v 1.70 2007/05/17 23:31:49 tgl Exp $
  *
  *	Jon Postel RIP 16 Oct 1998
  */
@@ -1142,6 +1142,8 @@ inet_client_addr(PG_FUNCTION_ARGS)
 	if (ret)
 		PG_RETURN_NULL();
 
+	clean_ipv6_addr(port->raddr.addr.ss_family, remote_host);
+
 	PG_RETURN_INET_P(network_in(remote_host, false));
 }
 
@@ -1216,6 +1218,8 @@ inet_server_addr(PG_FUNCTION_ARGS)
 	if (ret)
 		PG_RETURN_NULL();
 
+	clean_ipv6_addr(port->laddr.addr.ss_family, local_host);
+
 	PG_RETURN_INET_P(network_in(local_host, false));
 }
 
@@ -1479,3 +1483,32 @@ inetmi(PG_FUNCTION_ARGS)
 
 	PG_RETURN_INT64(res);
 }
+
+
+/*
+ * clean_ipv6_addr --- remove any '%zone' part from an IPv6 address string
+ *
+ * XXX This should go away someday!
+ *
+ * This is a kluge needed because we don't yet support zones in stored inet
+ * values.  Since the result of getnameinfo() might include a zone spec,
+ * call this to remove it anywhere we want to feed getnameinfo's output to
+ * network_in.  Beats failing entirely.
+ *
+ * An alternative approach would be to let network_in ignore %-parts for
+ * itself, but that would mean we'd silently drop zone specs in user input,
+ * which seems not such a good idea.
+ */
+void
+clean_ipv6_addr(int addr_family, char *addr)
+{
+#ifdef HAVE_IPV6
+	if (addr_family == AF_INET6)
+	{
+		char *pct = strchr(addr, '%');
+
+		if (pct)
+			*pct = '\0';
+	}
+#endif
+}

src/backend/utils/adt/pgstatfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/pgstatfuncs.c,v 1.41 2007/03/30 18:34:55 mha Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/pgstatfuncs.c,v 1.42 2007/05/17 23:31:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -550,6 +550,8 @@ pg_stat_get_backend_client_addr(PG_FUNCTION_ARGS)
 	if (ret)
 		PG_RETURN_NULL();
 
+	clean_ipv6_addr(beentry->st_clientaddr.addr.ss_family, remote_host);
+
 	PG_RETURN_INET_P(DirectFunctionCall1(inet_in,
 										 CStringGetDatum(remote_host)));
 }

src/include/utils/builtins.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.292 2007/05/08 18:56:48 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.293 2007/05/17 23:31:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -797,6 +797,7 @@ extern Datum inetor(PG_FUNCTION_ARGS);
 extern Datum inetpl(PG_FUNCTION_ARGS);
 extern Datum inetmi_int8(PG_FUNCTION_ARGS);
 extern Datum inetmi(PG_FUNCTION_ARGS);
+extern void clean_ipv6_addr(int addr_family, char *addr);
 
 /* mac.c */
 extern Datum macaddr_in(PG_FUNCTION_ARGS);