Currently rpc_inline_rcv_pages() uses au_rslack to estimate the
size of the upper layer reply header. This is fine for auth flavors
where au_verfsize == au_rslack.
However, some auth flavors have more going on. krb5i for example has
two more words after the verifier, and another blob following the
RPC message. The calculation involving au_rslack pushes the upper
layer reply header too far into the rcv_buf.
au_rslack is still valuable: it's the amount of buffer space needed
for the reply, and is used when allocating the reply buffer. We'll
keep that.
But, add a new field that can be used to properly estimate the
location of the upper layer header in each RPC reply, based on the
auth flavor in use.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/sunrpc/auth.h | 9 ++++-----
net/sunrpc/auth_gss/auth_gss.c | 18 +++++++++++++-----
net/sunrpc/auth_null.c | 1 +
net/sunrpc/auth_unix.c | 1 +
net/sunrpc/clnt.c | 2 +-
5 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 359dfdd..5f9076f 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -74,13 +74,12 @@ struct rpc_cred {
struct rpc_authops;
struct rpc_auth {
unsigned int au_cslack; /* call cred size estimate */
- /* guess at number of u32's auth adds before
- * reply data; normally the verifier size: */
- unsigned int au_rslack;
+ unsigned int au_rslack; /* reply cred size estimate */
unsigned int au_verfsize; /* size of reply verifier */
+ unsigned int au_ralign; /* words before UL header */
- unsigned int au_flags; /* various flags */
- const struct rpc_authops *au_ops; /* operations */
+ unsigned int au_flags;
+ const struct rpc_authops *au_ops;
rpc_authflavor_t au_flavor; /* pseudoflavor (note may
* differ from the flavor in
* au_ops->au_flavor in gss
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 731e7a4..c67e2ad 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1017,6 +1017,7 @@ static void gss_pipe_free(struct gss_pipe *p)
auth->au_cslack = GSS_CRED_SLACK >> 2;
auth->au_rslack = GSS_VERF_SLACK >> 2;
auth->au_verfsize = GSS_VERF_SLACK >> 2;
+ auth->au_ralign = GSS_VERF_SLACK >> 2;
auth->au_flags = 0;
auth->au_ops = &authgss_ops;
auth->au_flavor = flavor;
@@ -1891,7 +1892,10 @@ static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
static int
gss_unwrap_resp_auth(struct rpc_cred *cred)
{
- cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize;
+ struct rpc_auth *auth = cred->cr_auth;
+
+ auth->au_rslack = auth->au_verfsize;
+ auth->au_ralign = auth->au_verfsize;
return 0;
}
@@ -1902,6 +1906,7 @@ static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
{
struct xdr_buf integ_buf, *rcv_buf = &rqstp->rq_rcv_buf;
u32 data_offset, mic_offset, integ_len, maj_stat;
+ struct rpc_auth *auth = cred->cr_auth;
struct xdr_netobj mic;
__be32 *p;
@@ -1928,8 +1933,8 @@ static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
if (maj_stat != GSS_S_COMPLETE)
goto bad_mic;
- cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + 2 +
- 1 + XDR_QUADLEN(mic.len);
+ auth->au_rslack = auth->au_verfsize + 2 + 1 + XDR_QUADLEN(mic.len);
+ auth->au_ralign = auth->au_verfsize + 2;
return 0;
unwrap_failed:
trace_rpcgss_unwrap_failed(task);
@@ -1949,6 +1954,7 @@ static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
{
struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf;
struct kvec *head = rqstp->rq_rcv_buf.head;
+ struct rpc_auth *auth = cred->cr_auth;
unsigned int savedlen = rcv_buf->len;
u32 offset, opaque_len, maj_stat;
__be32 *p;
@@ -1976,8 +1982,10 @@ static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
*/
xdr_init_decode(xdr, rcv_buf, p, rqstp);
- cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + 2 +
- XDR_QUADLEN(savedlen - rcv_buf->len);
+ auth->au_rslack = auth->au_verfsize + 2 +
+ XDR_QUADLEN(savedlen - rcv_buf->len);
+ auth->au_ralign = auth->au_verfsize + 2 +
+ XDR_QUADLEN(savedlen - rcv_buf->len);
return 0;
unwrap_failed:
trace_rpcgss_unwrap_failed(task);
diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c
index 9ae0824..41a633a 100644
--- a/net/sunrpc/auth_null.c
+++ b/net/sunrpc/auth_null.c
@@ -115,6 +115,7 @@ struct rpc_auth null_auth = {
.au_cslack = NUL_CALLSLACK,
.au_rslack = NUL_REPLYSLACK,
.au_verfsize = NUL_REPLYSLACK,
+ .au_ralign = NUL_REPLYSLACK,
.au_ops = &authnull_ops,
.au_flavor = RPC_AUTH_NULL,
.au_count = REFCOUNT_INIT(1),
diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
index a93c564..c048eb6 100644
--- a/net/sunrpc/auth_unix.c
+++ b/net/sunrpc/auth_unix.c
@@ -187,6 +187,7 @@
auth->au_verfsize = XDR_QUADLEN(size) + 2;
auth->au_rslack = XDR_QUADLEN(size) + 2;
+ auth->au_ralign = XDR_QUADLEN(size) + 2;
return 0;
}
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 4ea38b0..99bfeb1 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1180,7 +1180,7 @@ void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
/* Subtract one to force an extra word of buffer space for the
* payload's XDR pad to fall into the rcv_buf's tail iovec.
*/
- hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_rslack - 1;
+ hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
trace_rpc_reply_pages(req);
