[1593] Addressed (re)review points

Conversion between socket structures is now done via the templated
convertSockAddr() function.

src/bin/sockcreator/Makefile.am

@@ -15,4 +15,5 @@ CLEANFILES = *.gcno *.gcda
 pkglibexec_PROGRAMS = b10-sockcreator
 
 b10_sockcreator_SOURCES = sockcreator.cc sockcreator.h main.cc
-b10_sockcreator_LDADD = $(top_builddir)/src/lib/util/io/libutil_io.la
+b10_sockcreator_LDADD  = $(top_builddir)/src/lib/util/io/libutil_io.la
+b10_sockcreator_LDADD += $(top_builddir)/src/lib/exceptions/libexceptions.la

src/bin/sockcreator/sockcreator.cc

@@ -15,6 +15,7 @@
 #include "sockcreator.h"
 
 #include <util/io/fd.h>
+#include <util/io/sockaddr_util.h>
 
 #include <cerrno>
 #include <cstring>
@@ -25,6 +26,7 @@
 #include <netinet/in.h>
 
 using namespace isc::util::io;
+using namespace isc::util::io::internal;
 using namespace isc::socket_creator;
 
 namespace {
@@ -126,11 +128,11 @@ handleRequest(const int input_fd, const int output_fd,
     sockaddr_in6 addr_in6;
     switch (type[1]) { // The address family
 
-        // The casting to apparently incompatible types by reinterpret_cast
-        // is required by the C low-level interface.
+        // The casting to apparently incompatible types is required by the
+        // C low-level interface.
 
         case '4':
-            addr = reinterpret_cast<sockaddr*>(&addr_in);
+            addr = convertSockAddr(&addr_in);
             addr_len = sizeof(addr_in);
             memset(&addr_in, 0, sizeof(addr_in));
             addr_in.sin_family = AF_INET;
@@ -140,8 +142,8 @@ handleRequest(const int input_fd, const int output_fd,
             break;
 
         case '6':
-            addr = reinterpret_cast<sockaddr*>(&addr_in6);
-            addr_len = sizeof addr_in6;
+            addr = convertSockAddr(&addr_in6);
+            addr_len = sizeof(addr_in6);
             memset(&addr_in6, 0, sizeof(addr_in6));
             addr_in6.sin6_family = AF_INET6;
             readMessage(input_fd, &addr_in6.sin6_port,

src/lib/util/io/sockaddr_util.h

@@ -51,12 +51,26 @@ convertSockAddr(const SAType* sa) {
 }
 
 template <typename SAType>
+const SAType*
+convertSockAddr(const struct sockaddr* sa) {
+    const void* p = sa;
+    return (static_cast<const SAType*>(p));
+}
+
+template <typename SAType>
 struct sockaddr*
 convertSockAddr(SAType* sa) {
     void* p = sa;
     return (static_cast<struct sockaddr*>(p));
 }
 
+template <typename SAType>
+SAType*
+convertSockAddr(struct sockaddr* sa) {
+    void* p = sa;
+    return (static_cast<SAType*>(p));
+}
+
 }
 }
 }