Re: [PATCH v2 3/5] NFS: Add secinfo procedure

[Trond Myklebust <Trond.Myklebust@netapp.com>]

On Wed, 2011-01-05 at 14:49 -0500, Bryan Schumaker wrote: 
> This patch adds the nfs4 operation secinfo as a
> valid nfs rpc operation.
> 
> Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
> ---
>  fs/nfs/nfs4proc.c       |   35 +++++++++++++
>  fs/nfs/nfs4xdr.c        |  129 +++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/nfs4.h    |    1 +
>  include/linux/nfs_xdr.h |   34 ++++++++++++
>  4 files changed, 199 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index 962eb45..3fdf821 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -4537,6 +4537,40 @@ int nfs4_proc_fs_locations(struct inode *dir, const struct qstr *name,
>  	return status;
>  }
>  
> +static int _nfs4_proc_secinfo(struct inode *dir, const struct qstr *name, struct nfs4_secinfo_flavors *flavors)
> +{
> +	int status;
> +	struct nfs4_secinfo_arg args = {
> +		.dir_fh = NFS_FH(dir),
> +		.name   = name,
> +	};
> +	struct nfs4_secinfo_res res = {
> +		.flavors     = flavors,
> +	};
> +	struct rpc_message msg = {
> +		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SECINFO],
> +		.rpc_argp = &args,
> +		.rpc_resp = &res,
> +	};
> +
> +	dprintk("NFS call  secinfo %s\n", name->name);
> +	status = nfs4_call_sync(NFS_SERVER(dir)->client, NFS_SERVER(dir), &msg, &args.seq_args, &res.seq_res, 0);
> +	dprintk("NFS reply  secinfo: %d\n", status);
> +	return status;
> +}
> +
> +int nfs4_proc_secinfo(struct inode *dir, const struct qstr *name, struct nfs4_secinfo_flavors *flavors)
> +{
> +	struct nfs4_exception exception = { };
> +	int err;
> +	do {
> +		err = nfs4_handle_exception(NFS_SERVER(dir),
> +				_nfs4_proc_secinfo(dir, name, flavors),
> +				&exception);
> +	} while (exception.retry);
> +	return err;
> +}
> +
>  #ifdef CONFIG_NFS_V4_1
>  /*
>   * nfs4_proc_exchange_id()
> @@ -5608,6 +5642,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
>  	.clear_acl_cache = nfs4_zap_acl_attr,
>  	.close_context  = nfs4_close_context,
>  	.open_context	= nfs4_atomic_open,
> +	.secinfo	= nfs4_proc_secinfo,
>  };
>  
>  static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index 8e49688..020fa88 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -46,6 +46,7 @@
>  #include <linux/kdev_t.h>
>  #include <linux/sunrpc/clnt.h>
>  #include <linux/sunrpc/msg_prot.h>
> +#include <linux/sunrpc/gss_api.h>
>  #include <linux/nfs.h>
>  #include <linux/nfs4.h>
>  #include <linux/nfs_fs.h>
> @@ -253,6 +254,8 @@ static int nfs4_stat_to_errno(int);
>  				(encode_getattr_maxsz)
>  #define decode_fs_locations_maxsz \
>  				(0)
> +#define encode_secinfo_maxsz	(op_encode_hdr_maxsz + nfs4_name_maxsz)
> +#define decode_secinfo_maxsz	(op_decode_hdr_maxsz + 4 + (NFS_MAX_SECFLAVORS * (16 + GSS_OID_MAX_LEN)))
>  
>  #if defined(CONFIG_NFS_V4_1)
>  #define NFS4_MAX_MACHINE_NAME_LEN (64)
> @@ -676,6 +679,14 @@ static int nfs4_stat_to_errno(int);
>  				 decode_putfh_maxsz + \
>  				 decode_lookup_maxsz + \
>  				 decode_fs_locations_maxsz)
> +#define NFS4_enc_secinfo_sz 	(compound_encode_hdr_maxsz + \
> +				encode_sequence_maxsz + \
> +				encode_putfh_maxsz + \
> +				encode_secinfo_maxsz)
> +#define NFS4_dec_secinfo_sz	(compound_decode_hdr_maxsz + \
> +				decode_sequence_maxsz + \
> +				decode_putfh_maxsz + \
> +				decode_secinfo_maxsz)
>  #if defined(CONFIG_NFS_V4_1)
>  #define NFS4_enc_exchange_id_sz \
>  				(compound_encode_hdr_maxsz + \
> @@ -1616,6 +1627,18 @@ static void encode_delegreturn(struct xdr_stream *xdr, const nfs4_stateid *state
>  	hdr->replen += decode_delegreturn_maxsz;
>  }
>  
> +static void encode_secinfo(struct xdr_stream *xdr, const struct qstr *name, struct compound_hdr *hdr)
> +{
> +	int len = name->len;
> +	__be32 *p;
> +
> +	p = reserve_space(xdr, 8 + len);
> +	*p++ = cpu_to_be32(OP_SECINFO);
> +	xdr_encode_opaque(p, name->name, len);
> +	hdr->nops++;
> +	hdr->replen += decode_secinfo_maxsz;
> +}
> +
>  #if defined(CONFIG_NFS_V4_1)
>  /* NFSv4.1 operations */
>  static void encode_exchange_id(struct xdr_stream *xdr,
> @@ -2603,6 +2626,26 @@ static void nfs4_xdr_enc_layoutget(struct rpc_rqst *req,
>  }
>  #endif /* CONFIG_NFS_V4_1 */
>  
> +/*
> + * Encode SECINFO request
> + */
> +static int nfs4_xdr_enc_secinfo(struct rpc_rqst *req, uint32_t *p,
> +				struct nfs4_secinfo_arg *args)
> +{
> +	struct xdr_stream xdr;
> +	struct compound_hdr hdr = {
> +		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
> +	};
> +
> +	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
> +	encode_compound_hdr(&xdr, req, &hdr);
> +	encode_sequence(&xdr, &args->seq_args, &hdr);
> +	encode_putfh(&xdr, args->dir_fh, &hdr);
> +	encode_secinfo(&xdr, args->name, &hdr);
> +	encode_nops(&hdr);
> +	return 0;
> +}
> +
>  static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
>  {
>  	dprintk("nfs: %s: prematurely hit end of receive buffer. "
> @@ -4677,6 +4720,63 @@ static int decode_delegreturn(struct xdr_stream *xdr)
>  	return decode_op_hdr(xdr, OP_DELEGRETURN);
>  }
>  
> +static int decode_secinfo_gss(struct xdr_stream *xdr, struct nfs4_secinfo_flavor *flavor)
> +{
> +	__be32 *p;
> +
> +	p = xdr_inline_decode(xdr, 4);
> +	if (unlikely(!p))
> +		goto out_overflow;
> +	flavor->gss.sec_oid4.len = be32_to_cpup(p);

Please check that the resulting length is <
sizeof(flavor->gss.sec_oid4.data)

> +
> +	p = xdr_inline_decode(xdr, flavor->gss.sec_oid4.len + 8);
> +	if (unlikely(!p))
> +		goto out_overflow;
> +
> +	memcpy(flavor->gss.sec_oid4.data, p, flavor->gss.sec_oid4.len);
> +	p += XDR_QUADLEN(flavor->gss.sec_oid4.len);
> +	flavor->gss.qop4 = be32_to_cpup(p++);
> +	flavor->gss.service = be32_to_cpup(p);
> +
> +	return 0;
> +
> +out_overflow:
> +	print_overflow_msg(__func__, xdr);
> +	return -EIO;
> +}
> +
> +static int decode_secinfo(struct xdr_stream *xdr, struct nfs4_secinfo_res *res)
> +{
> +	struct nfs4_secinfo_flavor *sec_flavor;
> +	int status;
> +	__be32 *p;
> +	int i;
> +
> +	status = decode_op_hdr(xdr, OP_SECINFO);
> +	p = xdr_inline_decode(xdr, 4);
> +	if (unlikely(!p))
> +		goto out_overflow;
> +	res->flavors->num_flavors = be32_to_cpup(p);

Please check that we don't overflow the res->flavors->flavors[] buffer.
It looks from 4/5 as if you are using a page as back end storage, so
perhaps the best thing to do here is to pass the buffer size as part of
the res->flavors structure.

> +
> +	for (i = 0; i < res->flavors->num_flavors; i++) {
> +		sec_flavor = &res->flavors->flavors[i];
> +
> +		p = xdr_inline_decode(xdr, 4);
> +		if (unlikely(!p))
> +			goto out_overflow;
> +		sec_flavor->flavor = be32_to_cpup(p);
> +
> +		if (sec_flavor->flavor == RPC_AUTH_GSS)
> +			decode_secinfo_gss(xdr, sec_flavor);
> +	}
> +
> +	return 0;
> +
> +out_overflow:
> +	print_overflow_msg(__func__, xdr);
> +	return -EIO;
> +}
> +
>  #if defined(CONFIG_NFS_V4_1)
>  static int decode_exchange_id(struct xdr_stream *xdr,
>  			      struct nfs41_exchange_id_res *res)
> @@ -6064,6 +6164,34 @@ out:
>  }
>  #endif /* CONFIG_NFS_V4_1 */
>  
> +/*
> + * Decode SECINFO response
> + */
> +static int nfs4_xdr_dec_secinfo(struct rpc_rqst *rqstp, uint32_t *p,
> +				struct nfs4_secinfo_res *res)
> +{
> +	struct xdr_stream xdr;
> +	struct compound_hdr hdr;
> +	int status;
> +
> +	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
> +	status = decode_compound_hdr(&xdr, &hdr);
> +	if (status)
> +		goto out;
> +	status = decode_sequence(&xdr, &res->seq_res, rqstp);
> +	if (status)
> +		goto out;
> +	status = decode_putfh(&xdr);
> +	if (status)
> +		goto out;
> +	status = decode_secinfo(&xdr, res);
> +	if (status)
> +		goto out;
> +out:
> +	return status;
> +	return NFS_OK;
> +}
> +
>  /**
>   * nfs4_decode_dirent - Decode a single NFSv4 directory entry stored in
>   *                      the local page cache.
> @@ -6265,6 +6393,7 @@ struct rpc_procinfo	nfs4_procedures[] = {
>  	PROC(SETACL,		enc_setacl,		dec_setacl),
>  	PROC(FS_LOCATIONS,	enc_fs_locations,	dec_fs_locations),
>  	PROC(RELEASE_LOCKOWNER,	enc_release_lockowner,	dec_release_lockowner),
> +	PROC(SECINFO,		enc_secinfo,		dec_secinfo),
>  #if defined(CONFIG_NFS_V4_1)
>  	PROC(EXCHANGE_ID,	enc_exchange_id,	dec_exchange_id),
>  	PROC(CREATE_SESSION,	enc_create_session,	dec_create_session),
> diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
> index 4925b22..b4904b2 100644
> --- a/include/linux/nfs4.h
> +++ b/include/linux/nfs4.h
> @@ -540,6 +540,7 @@ enum {
>  	NFSPROC4_CLNT_SETACL,
>  	NFSPROC4_CLNT_FS_LOCATIONS,
>  	NFSPROC4_CLNT_RELEASE_LOCKOWNER,
> +	NFSPROC4_CLNT_SECINFO,
>  
>  	/* nfs41 */
>  	NFSPROC4_CLNT_EXCHANGE_ID,
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index a3bc46f..edd74e7 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -3,6 +3,7 @@
>  
>  #include <linux/nfsacl.h>
>  #include <linux/nfs3.h>
> +#include <linux/sunrpc/gss_api.h>
>  
>  /*
>   * To change the maximum rsize and wsize supported by the NFS client, adjust
> @@ -937,6 +938,38 @@ struct nfs4_fs_locations_res {
>  	struct nfs4_sequence_res	seq_res;
>  };
>  
> +struct nfs4_secinfo_oid {
> +	unsigned int len;
> +	char data[GSS_OID_MAX_LEN];
> +};
> +
> +struct nfs4_secinfo_gss {
> +	struct nfs4_secinfo_oid sec_oid4;
> +	unsigned int qop4;
> +	unsigned int service;
> +};
> +
> +struct nfs4_secinfo_flavor {
> +	unsigned int 		flavor;
> +	struct nfs4_secinfo_gss	gss;
> +};
> +
> +struct nfs4_secinfo_flavors {
> +	unsigned int num_flavors;
> +	struct nfs4_secinfo_flavor flavors[0];
> +};
> +
> +struct nfs4_secinfo_arg {
> +	const struct nfs_fh		*dir_fh;
> +	const struct qstr		*name;
> +	struct nfs4_sequence_args	seq_args;
> +};
> +
> +struct nfs4_secinfo_res {
> +	struct nfs4_secinfo_flavors	*flavors;
> +	struct nfs4_sequence_res	seq_res;
> +};
> +
>  #endif /* CONFIG_NFS_V4 */
>  
>  struct nfstime4 {
> @@ -1107,6 +1140,7 @@ struct nfs_rpc_ops {
>  				struct nfs_open_context *ctx,
>  				int open_flags,
>  				struct iattr *iattr);
> +	int	(*secinfo)(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
>  };
>  
>  /*

-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com