Preserve ABI compatibility between glibc's RPC implementation and
the legacy RPC implementation in libtirpc by moving the rq_xprt
field in the TI-RPC version of the svc_req struct so it is
backwards compatible with the legacy version of this structure.
Linux's legacy svc_req struct, from /usr/include/rpc/svc.h, looks
like this:
struct svc_req {
rpcprog_t rq_prog; /* service program number */
rpcvers_t rq_vers; /* service protocol version */
rpcproc_t rq_proc; /* the desired procedure */
struct opaque_auth rq_cred; /* raw creds from the wire */
caddr_t rq_clntcred; /* read only cooked cred */
SVCXPRT *rq_xprt; /* associated transport */
};
The new TI-RPC svc_req struct, from /usr/include/tirpc/rpc/svc.h,
looks like this:
struct svc_req {
u_int32_t rq_prog; /* service program number */
u_int32_t rq_vers; /* service protocol version */
u_int32_t rq_proc; /* the desired procedure */
struct opaque_auth rq_cred; /* raw creds from the wire */
void *rq_clntcred; /* read only cooked cred */
caddr_t rq_clntname; /* read only client name */
caddr_t rq_svcname; /* read only cooked service cred */
SVCXPRT *rq_xprt; /* associated transport */
};
Note the extra fields rq_clntname and rq_svcname. These are used for
TI-RPC's RPCSEC GSS flavor support.
This issue came to light because rpc.statd still uses only legacy RPC
calls, and thus includes /usr/include/rpc/svc.h. However, other parts
of nfs-utils now link with TI-RPC, so the legacy RPC functions in
libtirpc are used in favor of glibc's RPC functions. The libtirpc svc
functions use the new svc_req struct, but rpc.statd uses the old
svc_req struct.
Since the svc_req fields were different, rpc.statd broke after recent
IPv6-related changes, even though I hadn't made any changes to it.
Note that rpc.mountd also references the rq_xprt field, so it has the
same issue.
In most operating systems, there is only one rpc/svc.h and one version
of svc_req so this is not a problem. We should audit all of the
structures and functions under /usr/include/rpc and
/usr/include/tirpc/rpc to ensure we have a reasonable level of
backwards compatibility until such a time it is decided to merge these
implementations or get rid of RPC support in glibc.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
tirpc/rpc/svc.h | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/tirpc/rpc/svc.h b/tirpc/rpc/svc.h
index ec5914f..ea2985d 100644
--- a/tirpc/rpc/svc.h
+++ b/tirpc/rpc/svc.h
@@ -131,14 +131,17 @@ typedef struct __rpc_svcxprt {
* Service request
*/
struct svc_req {
+ /* ORDER: compatibility with legacy RPC */
u_int32_t rq_prog; /* service program number */
u_int32_t rq_vers; /* service protocol version */
u_int32_t rq_proc; /* the desired procedure */
struct opaque_auth rq_cred; /* raw creds from the wire */
void *rq_clntcred; /* read only cooked cred */
+ SVCXPRT *rq_xprt; /* associated transport */
+
+ /* New with TI-RPC */
caddr_t rq_clntname; /* read only client name */
caddr_t rq_svcname; /* read only cooked service cred */
- SVCXPRT *rq_xprt; /* associated transport */
};
/*
--
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