SUNRPC: Add svc_rqst::rq_auth_stat

I'd like to take commit 4532608d71c8 ("SUNRPC: Clean up generic
dispatcher code") even further by using only private local SVC
dispatchers for all kernel RPC services. This change would enable
the removal of the logic that switches between
svc_generic_dispatch() and a service's private dispatcher, and
simplify the invocation of the service's pc_release method
so that humans can visually verify that it is always invoked
properly.

All that will come later.

First, let's provide a better way to return authentication errors
from SVC dispatcher functions. Instead of overloading the dispatch
method's *statp argument, add a field to struct svc_rqst that can
hold an error value.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 21 insertions, 22 deletions

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index a81be45f40d9..635449ed7af6 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -707,11 +707,11 @@ svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
 /*
  * Verify the checksum on the header and return SVC_OK on success.
  * Otherwise, return SVC_DROP (in the case of a bad sequence number)
- * or return SVC_DENIED and indicate error in authp.
+ * or return SVC_DENIED and indicate error in rqstp->rq_auth_stat.
  */
 static int
 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
-		  __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp)
+		  __be32 *rpcstart, struct rpc_gss_wire_cred *gc)
 {
 	struct gss_ctx		*ctx_id = rsci->mechctx;
 	struct xdr_buf		rpchdr;
@@ -725,7 +725,7 @@ gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
 	iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
 	xdr_buf_from_iov(&iov, &rpchdr);
 
-	*authp = rpc_autherr_badverf;
+	rqstp->rq_auth_stat = rpc_autherr_badverf;
 	if (argv->iov_len < 4)
 		return SVC_DENIED;
 	flavor = svc_getnl(argv);
@@ -737,13 +737,13 @@ gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
 	if (rqstp->rq_deferred) /* skip verification of revisited request */
 		return SVC_OK;
 	if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) {
-		*authp = rpcsec_gsserr_credproblem;
+		rqstp->rq_auth_stat = rpcsec_gsserr_credproblem;
 		return SVC_DENIED;
 	}
 
 	if (gc->gc_seq > MAXSEQ) {
 		trace_rpcgss_svc_seqno_large(rqstp, gc->gc_seq);
-		*authp = rpcsec_gsserr_ctxproblem;
+		rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem;
 		return SVC_DENIED;
 	}
 	if (!gss_check_seq_num(rqstp, rsci, gc->gc_seq))
@@ -1142,7 +1142,7 @@ static void gss_free_in_token_pages(struct gssp_in_token *in_token)
 }
 
 static int gss_read_proxy_verf(struct svc_rqst *rqstp,
-			       struct rpc_gss_wire_cred *gc, __be32 *authp,
+			       struct rpc_gss_wire_cred *gc,
 			       struct xdr_netobj *in_handle,
 			       struct gssp_in_token *in_token)
 {
@@ -1151,7 +1151,7 @@ static int gss_read_proxy_verf(struct svc_rqst *rqstp,
 	int pages, i, res, pgto, pgfrom;
 	size_t inlen, to_offs, from_offs;
 
-	res = gss_read_common_verf(gc, argv, authp, in_handle);
+	res = gss_read_common_verf(gc, argv, &rqstp->rq_auth_stat, in_handle);
 	if (res)
 		return res;
 
@@ -1227,7 +1227,7 @@ gss_write_resv(struct kvec *resv, size_t size_limit,
  * Otherwise, drop the request pending an answer to the upcall.
  */
 static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
-			struct rpc_gss_wire_cred *gc, __be32 *authp)
+				   struct rpc_gss_wire_cred *gc)
 {
 	struct kvec *argv = &rqstp->rq_arg.head[0];
 	struct kvec *resv = &rqstp->rq_res.head[0];
@@ -1236,7 +1236,7 @@ static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
 
 	memset(&rsikey, 0, sizeof(rsikey));
-	ret = gss_read_verf(gc, argv, authp,
+	ret = gss_read_verf(gc, argv, &rqstp->rq_auth_stat,
 			    &rsikey.in_handle, &rsikey.in_token);
 	if (ret)
 		return ret;
@@ -1339,7 +1339,7 @@ out:
 }
 
 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
-			struct rpc_gss_wire_cred *gc, __be32 *authp)
+				  struct rpc_gss_wire_cred *gc)
 {
 	struct kvec *resv = &rqstp->rq_res.head[0];
 	struct xdr_netobj cli_handle;
@@ -1351,8 +1351,7 @@ static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
 	memset(&ud, 0, sizeof(ud));
-	ret = gss_read_proxy_verf(rqstp, gc, authp,
-				  &ud.in_handle, &ud.in_token);
+	ret = gss_read_proxy_verf(rqstp, gc, &ud.in_handle, &ud.in_token);
 	if (ret)
 		return ret;
 
@@ -1525,7 +1524,7 @@ static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
  * response here and return SVC_COMPLETE.
  */
 static int
-svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
+svcauth_gss_accept(struct svc_rqst *rqstp)
 {
 	struct kvec	*argv = &rqstp->rq_arg.head[0];
 	struct kvec	*resv = &rqstp->rq_res.head[0];
@@ -1538,7 +1537,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 	int		ret;
 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
 
-	*authp = rpc_autherr_badcred;
+	rqstp->rq_auth_stat = rpc_autherr_badcred;
 	if (!svcdata)
 		svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
 	if (!svcdata)
@@ -1575,22 +1574,22 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 	if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
 		goto auth_err;
 
-	*authp = rpc_autherr_badverf;
+	rqstp->rq_auth_stat = rpc_autherr_badverf;
 	switch (gc->gc_proc) {
 	case RPC_GSS_PROC_INIT:
 	case RPC_GSS_PROC_CONTINUE_INIT:
 		if (use_gss_proxy(SVC_NET(rqstp)))
-			return svcauth_gss_proxy_init(rqstp, gc, authp);
+			return svcauth_gss_proxy_init(rqstp, gc);
 		else
-			return svcauth_gss_legacy_init(rqstp, gc, authp);
+			return svcauth_gss_legacy_init(rqstp, gc);
 	case RPC_GSS_PROC_DATA:
 	case RPC_GSS_PROC_DESTROY:
 		/* Look up the context, and check the verifier: */
-		*authp = rpcsec_gsserr_credproblem;
+		rqstp->rq_auth_stat = rpcsec_gsserr_credproblem;
 		rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
 		if (!rsci)
 			goto auth_err;
-		switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
+		switch (gss_verify_header(rqstp, rsci, rpcstart, gc)) {
 		case SVC_OK:
 			break;
 		case SVC_DENIED:
@@ -1600,7 +1599,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 		}
 		break;
 	default:
-		*authp = rpc_autherr_rejectedcred;
+		rqstp->rq_auth_stat = rpc_autherr_rejectedcred;
 		goto auth_err;
 	}
 
@@ -1616,13 +1615,13 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 		svc_putnl(resv, RPC_SUCCESS);
 		goto complete;
 	case RPC_GSS_PROC_DATA:
-		*authp = rpcsec_gsserr_ctxproblem;
+		rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem;
 		svcdata->verf_start = resv->iov_base + resv->iov_len;
 		if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
 			goto auth_err;
 		rqstp->rq_cred = rsci->cred;
 		get_group_info(rsci->cred.cr_group_info);
-		*authp = rpc_autherr_badcred;
+		rqstp->rq_auth_stat = rpc_autherr_badcred;
 		switch (gc->gc_svc) {
 		case RPC_GSS_SVC_NONE:
 			break;