nfs-utils: Include legacy or TI-RPC headers, not both

Data type incompatibilities between the legacy RPC headers and the
TI-RPC headers mean we can't use libtirpc with code that was compiled
against the legacy RPC headers.  The definition of rpcprog_t for
example is "unsigned long" in the legacy library, but it's "uint32_t"
for TI-RPC.  On 32-bit systems, these types happen to have the same
width, but on 64-bit systems they don't, making more complex data
structures that use these types in fields ABI incompatible.

Adopt a new strategy to deal with this issue.  When --enable-tirpc is
set, append "-I/usr/include/tirpc" to the compilation steps.  This
should cause the compiler to grab the tirpc/ headers instead of the
legacy headers.  Now, for TI-RPC builds, the TI-RPC legacy functions
and the TI-RPC headers will be used.  On legacy systems, the legacy
headers and legacy glibc RPC implementation will be used.

A new ./configure option is introduced to allow system integrators to
use TI-RPC headers in some other location than /usr/include/tirpc.
/usr/include/tirpc remains the default setting for this new option.

The gssd implementation presents a few challenges, but it turns out
the gssglue library is similar to the auth_gss pieces of TI-RPC.  To
avoid similar header incompatibility issues, gssd now uses libtirpc
instead of libgssglue if --enable-tirpc is specified.  There may be
other issues to tackle with gssd, but for now, we just make sure it
builds with --enable-tirpc.

Note also: svc_getcaller() is a macro in both cases that points to
a sockaddr field in the svc_req structure.  The legacy version points
to a sockaddr_in type field, but the TI-RPC version points to a
sockaddr_in6 type field.

rpc.mountd unconditionally casts the result of svc_getcaller() to a
sockaddr_in *.  This should be OK for TI-RPC as well, since rpc.mountd
still uses legacy RPC calls (provided by glibc, or emulated by TI-RPC)
to set up its listeners, and therefore rpc.mountd callers will always
be from AF_INET addresses for now.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/aclocal/libtirpc.m4 b/aclocal/libtirpc.m4
index b1f3669..af4c7d3 100644
--- a/aclocal/libtirpc.m4
+++ b/aclocal/libtirpc.m4
@@ -2,6 +2,12 @@ dnl Checks for TI-RPC library and headers
 dnl
 AC_DEFUN([AC_LIBTIRPC], [
 
+  AC_ARG_WITH([tirpcinclude],
+              [AC_HELP_STRING([--with-tirpcinclude=DIR],
+                              [use TI-RPC headers in DIR])],
+              [tirpc_header_dir=$withval],
+              [tirpc_header_dir=/usr/include/tirpc])
+
   dnl if --enable-tirpc was specifed, the following components
   dnl must be present, and we set up HAVE_ macros for them.
 
@@ -12,8 +18,10 @@ AC_DEFUN([AC_LIBTIRPC], [
                  [AC_MSG_ERROR([libtirpc not found.])])
 
     dnl also must have the headers installed where we expect
-    AC_CHECK_HEADERS([tirpc/netconfig.h], ,
+    dnl look for headers; add -I compiler option if found
+    AC_CHECK_HEADERS([${tirpc_header_dir}/netconfig.h], ,
                      [AC_MSG_ERROR([libtirpc headers not found.])])
+    AC_SUBST([AM_CPPFLAGS], ["-I${tirpc_header_dir}"])
 
   fi