SUNRPC refactor rpcauth_checkverf error returns

Most of the time an error from the credops crvalidate function means the
server has sent us a garbage verifier. The gss_validate function is the
exception where there is an -EACCES case if the user GSS_context on the client
has expired.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

4 files changed, 19 insertions, 13 deletions

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index a9b1edca917c..30eb502135bb 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1501,6 +1501,7 @@ gss_validate(struct rpc_task *task, __be32 *p)
         struct xdr_netobj mic;
         u32             flav,len;
         u32             maj_stat;
+        __be32          *ret = ERR_PTR(-EIO);
 
         dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
 
@@ -1516,6 +1517,7 @@ gss_validate(struct rpc_task *task, __be32 *p)
         mic.data = (u8 *)p;
         mic.len = len;
 
+        ret = ERR_PTR(-EACCES);
         maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
         if (maj_stat == GSS_S_CONTEXT_EXPIRED)
                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
@@ -1533,8 +1535,9 @@ gss_validate(struct rpc_task *task, __be32 *p)
         return p + XDR_QUADLEN(len);
 out_bad:
         gss_put_ctx(ctx);
-        dprintk("RPC: %5u %s failed.\n", task->tk_pid, __func__);
-        return NULL;
+        dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
+                PTR_ERR(ret));
+        return ret;
 }
 
 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c
index 4664eb46baa0..f0ebe07978a2 100644
--- a/net/sunrpc/auth_null.c
+++ b/net/sunrpc/auth_null.c
@@ -88,13 +88,13 @@ nul_validate(struct rpc_task *task, __be32 *p)
         flavor = ntohl(*p++);
         if (flavor != RPC_AUTH_NULL) {
                 printk("RPC: bad verf flavor: %u\n", flavor);
-                return NULL;
+                return ERR_PTR(-EIO);
         }
 
         size = ntohl(*p++);
         if (size != 0) {
                 printk("RPC: bad verf size: %u\n", size);
-                return NULL;
+                return ERR_PTR(-EIO);
         }
 
         return p;
diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
index e52d832f9a2a..d5d692366294 100644
--- a/net/sunrpc/auth_unix.c
+++ b/net/sunrpc/auth_unix.c
@@ -192,13 +192,13 @@ unx_validate(struct rpc_task *task, __be32 *p)
             flavor != RPC_AUTH_UNIX &&
             flavor != RPC_AUTH_SHORT) {
                 printk("RPC: bad verf flavor: %u\n", flavor);
-                return NULL;
+                return ERR_PTR(-EIO);
         }
 
         size = ntohl(*p++);
         if (size > RPC_MAX_AUTH_SIZE) {
                 printk("RPC: giant verf size: %u\n", size);
-                return NULL;
+                return ERR_PTR(-EIO);
         }
         task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
         p += (size >> 2);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 631085ff0ad9..0cd5b6d5c75e 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2072,7 +2072,8 @@ rpc_verify_header(struct rpc_task *task)
                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
                        task->tk_rqstp->rq_rcv_buf.len);
-                goto out_eio;
+                error = -EIO;
+                goto out_err;
         }
         if ((len -= 3) < 0)
                 goto out_overflow;
@@ -2081,6 +2082,7 @@ rpc_verify_header(struct rpc_task *task)
         if ((n = ntohl(*p++)) != RPC_REPLY) {
                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
                         task->tk_pid, __func__, n);
+                error = -EIO;
                 goto out_garbage;
         }
 
@@ -2099,7 +2101,8 @@ rpc_verify_header(struct rpc_task *task)
                         dprintk("RPC: %5u %s: RPC call rejected, "
                                 "unknown error: %x\n",
                                 task->tk_pid, __func__, n);
-                        goto out_eio;
+                        error = -EIO;
+                        goto out_err;
                 }
                 if (--len < 0)
                         goto out_overflow;
@@ -2144,9 +2147,11 @@ rpc_verify_header(struct rpc_task *task)
                                 task->tk_pid, __func__, n);
                 goto out_err;
         }
-        if (!(p = rpcauth_checkverf(task, p))) {
-                dprintk("RPC: %5u %s: auth check failed\n",
-                                task->tk_pid, __func__);
+        p = rpcauth_checkverf(task, p);
+        if (IS_ERR(p)) {
+                error = PTR_ERR(p);
+                dprintk("RPC: %5u %s: auth check failed with %d\n",
+                                task->tk_pid, __func__, error);
                 goto out_garbage;               /* bad verifier, retry */
         }
         len = p - (__be32 *)iov->iov_base - 1;
@@ -2199,8 +2204,6 @@ out_garbage:
 out_retry:
                 return ERR_PTR(-EAGAIN);
         }
-out_eio:
-        error = -EIO;
 out_err:
         rpc_exit(task, error);
         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,