nfsd4: check backchannel attributes on create_session

Make sure the client gives us an adequate backchannel.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2013-04-09 11:34:36 -04:00
parent 55c760cfc4
commit 06b332a522
4 changed files with 52 additions and 24 deletions

View File

@ -37,6 +37,7 @@
#include "nfsd.h"
#include "state.h"
#include "netns.h"
#include "xdr4cb.h"
#define NFSDDBG_FACILITY NFSDDBG_PROC
@ -53,30 +54,6 @@ enum {
NFSPROC4_CLNT_CB_SEQUENCE,
};
#define NFS4_MAXTAGLEN 20
#define NFS4_enc_cb_null_sz 0
#define NFS4_dec_cb_null_sz 0
#define cb_compound_enc_hdr_sz 4
#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
#define cb_sequence_enc_sz (sessionid_sz + 4 + \
1 /* no referring calls list yet */)
#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
#define op_enc_sz 1
#define op_dec_sz 2
#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
cb_sequence_enc_sz + \
1 + enc_stateid_sz + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
cb_sequence_dec_sz + \
op_dec_sz)
struct nfs4_cb_compound_hdr {
/* args */
u32 ident; /* minorversion 0 only */

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@ -42,6 +42,7 @@
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/addr.h>
#include "xdr4.h"
#include "xdr4cb.h"
#include "vfs.h"
#include "current_stateid.h"
@ -1794,6 +1795,27 @@ static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca, struct nfs
return nfs_ok;
}
static __be32 check_backchannel_attrs(struct nfsd4_channel_attrs *ca)
{
ca->headerpadsz = 0;
/*
* These RPC_MAX_HEADER macros are overkill, especially since we
* don't even do gss on the backchannel yet. But this is still
* less than 1k. Tighten up this estimate in the unlikely event
* it turns out to be a problem for some client:
*/
if (ca->maxreq_sz < NFS4_enc_cb_recall_sz + RPC_MAX_HEADER_WITH_AUTH)
return nfserr_toosmall;
if (ca->maxresp_sz < NFS4_dec_cb_recall_sz + RPC_MAX_REPHEADER_WITH_AUTH)
return nfserr_toosmall;
ca->maxresp_cached = 0;
if (ca->maxops < 2)
return nfserr_toosmall;
return nfs_ok;
}
__be32
nfsd4_create_session(struct svc_rqst *rqstp,
struct nfsd4_compound_state *cstate,
@ -1810,6 +1832,9 @@ nfsd4_create_session(struct svc_rqst *rqstp,
if (cr_ses->flags & ~SESSION4_FLAG_MASK_A)
return nfserr_inval;
status = check_forechannel_attrs(&cr_ses->fore_channel, nn);
if (status)
return status;
status = check_backchannel_attrs(&cr_ses->back_channel);
if (status)
return status;
status = nfserr_jukebox;

23
fs/nfsd/xdr4cb.h Normal file
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@ -0,0 +1,23 @@
#define NFS4_MAXTAGLEN 20
#define NFS4_enc_cb_null_sz 0
#define NFS4_dec_cb_null_sz 0
#define cb_compound_enc_hdr_sz 4
#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
#define cb_sequence_enc_sz (sessionid_sz + 4 + \
1 /* no referring calls list yet */)
#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
#define op_enc_sz 1
#define op_dec_sz 2
#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
cb_sequence_enc_sz + \
1 + enc_stateid_sz + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
cb_sequence_dec_sz + \
op_dec_sz)

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@ -138,6 +138,9 @@ typedef __be32 rpc_fraghdr;
#define RPC_MAX_HEADER_WITH_AUTH \
(RPC_CALLHDRSIZE + 2*(2+RPC_MAX_AUTH_SIZE/4))
#define RPC_MAX_REPHEADER_WITH_AUTH \
(RPC_REPHDRSIZE + (2 + RPC_MAX_AUTH_SIZE/4))
/*
* RFC1833/RFC3530 rpcbind (v3+) well-known netid's.
*/