+/*
+ * Having read the cred already and found we're in the context
+ * initiation case, read the verifier and initiate (or check the results
+ * of) upcalls to userspace for help with context initiation. If
+ * the upcall results are available, write the verifier and result.
+ * Otherwise, drop the request pending an answer to the upcall.
+ */
+static int svcauth_gss_handle_init(struct svc_rqst *rqstp,
+ struct rpc_gss_wire_cred *gc, __be32 *authp)
+{
+ struct kvec *argv = &rqstp->rq_arg.head[0];
+ struct kvec *resv = &rqstp->rq_res.head[0];
+ struct xdr_netobj tmpobj;
+ struct rsi *rsip, rsikey;
+ int ret;
+
+ /* Read the verifier; should be NULL: */
+ *authp = rpc_autherr_badverf;
+ if (argv->iov_len < 2 * 4)
+ return SVC_DENIED;
+ if (svc_getnl(argv) != RPC_AUTH_NULL)
+ return SVC_DENIED;
+ if (svc_getnl(argv) != 0)
+ return SVC_DENIED;
+
+ /* Martial context handle and token for upcall: */
+ *authp = rpc_autherr_badcred;
+ if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
+ return SVC_DENIED;
+ memset(&rsikey, 0, sizeof(rsikey));
+ if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx))
+ return SVC_DROP;
+ *authp = rpc_autherr_badverf;
+ if (svc_safe_getnetobj(argv, &tmpobj)) {
+ kfree(rsikey.in_handle.data);
+ return SVC_DENIED;
+ }
+ if (dup_netobj(&rsikey.in_token, &tmpobj)) {
+ kfree(rsikey.in_handle.data);
+ return SVC_DROP;
+ }
+
+ /* Perform upcall, or find upcall result: */
+ rsip = rsi_lookup(&rsikey);
+ rsi_free(&rsikey);
+ if (!rsip)
+ return SVC_DROP;
+ switch (cache_check(&rsi_cache, &rsip->h, &rqstp->rq_chandle)) {
+ case -EAGAIN:
+ case -ETIMEDOUT:
+ case -ENOENT:
+ /* No upcall result: */
+ return SVC_DROP;
+ case 0:
+ ret = SVC_DROP;
+ /* Got an answer to the upcall; use it: */
+ if (gss_write_init_verf(rqstp, rsip))
+ goto out;
+ if (resv->iov_len + 4 > PAGE_SIZE)
+ goto out;
+ svc_putnl(resv, RPC_SUCCESS);
+ if (svc_safe_putnetobj(resv, &rsip->out_handle))
+ goto out;
+ if (resv->iov_len + 3 * 4 > PAGE_SIZE)
+ goto out;
+ svc_putnl(resv, rsip->major_status);
+ svc_putnl(resv, rsip->minor_status);
+ svc_putnl(resv, GSS_SEQ_WIN);
+ if (svc_safe_putnetobj(resv, &rsip->out_token))
+ goto out;
+ }
+ ret = SVC_COMPLETE;
+out:
+ cache_put(&rsip->h, &rsi_cache);
+ return ret;
+}
+