path: root/net/sunrpc/auth_gss/gss_rpc_xdr.c

/*
 * GSS Proxy upcall module
 *
 *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/sunrpc/svcauth.h>
#include "gss_rpc_xdr.h"

static int gssx_enc_bool(struct xdr_stream *xdr, int v)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4);
	if (unlikely(p == NULL))
		return -ENOSPC;
	*p = v ? xdr_one : xdr_zero;
	return 0;
}

static int gssx_dec_bool(struct xdr_stream *xdr, u32 *v)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		return -ENOSPC;
	*v = be32_to_cpu(*p);
	return 0;
}

static int gssx_enc_buffer(struct xdr_stream *xdr,
			   gssx_buffer *buf)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, sizeof(u32) + buf->len);
	if (!p)
		return -ENOSPC;
	xdr_encode_opaque(p, buf->data, buf->len);
	return 0;
}

static int gssx_enc_in_token(struct xdr_stream *xdr,
			     struct gssp_in_token *in)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4);
	if (!p)
		return -ENOSPC;
	*p = cpu_to_be32(in->page_len);

	/* all we need to do is to write pages */
	xdr_write_pages(xdr, in->pages, in->page_base, in->page_len);

	return 0;
}


static int gssx_dec_buffer(struct xdr_stream *xdr,
			   gssx_buffer *buf)
{
	u32 length;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		return -ENOSPC;

	length = be32_to_cpup(p);
	p = xdr_inline_decode(xdr, length);
	if (unlikely(p == NULL))
		return -ENOSPC;

	if (buf->len == 0) {
		/* we intentionally are not interested in this buffer */
		return 0;
	}
	if (length > buf->len)
		return -ENOSPC;

	if (!buf->data) {
		buf->data = kmemdup(p, length, GFP_KERNEL);
		if (!buf->data)
			return -ENOMEM;
	} else {
		memcpy(buf->data, p, length);
	}
	buf->len = length;
	return 0;
}

static int gssx_enc_option(struct xdr_stream *xdr,
			   struct gssx_option *opt)
{
	int err;

	err = gssx_enc_buffer(xdr, &opt->option);
	if (err)
		return err;
	err = gssx_enc_buffer(xdr, &opt->value);
	return err;
}

static int gssx_dec_option(struct xdr_stream *xdr,
			   struct gssx_option *opt)
{
	int err;

	err = gssx_dec_buffer(xdr, &opt->option);
	if (err)
		return err;
	err = gssx_dec_buffer(xdr, &opt->value);
	return err;
}

static int dummy_enc_opt_array(struct xdr_stream *xdr,
				struct gssx_option_array *oa)
{
	__be32 *p;

	if (oa->count != 0)
		return -EINVAL;

	p = xdr_reserve_space(xdr, 4);
	if (!p)
		return -ENOSPC;
	*p = 0;

	return 0;
}

static int dummy_dec_opt_array(struct xdr_stream *xdr,
				struct gssx_option_array *oa)
{
	struct gssx_option dummy;
	u32 count, i;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		return -ENOSPC;
	count = be32_to_cpup(p++);
	memset(&dummy, 0, sizeof(dummy));
	for (i = 0; i < count; i++) {
		gssx_dec_option(xdr, &dummy);
	}

	oa->count = 0;
	oa->data = NULL;
	return 0;
}

static int get_host_u32(struct xdr_stream *xdr, u32 *res)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (!p)
		return -EINVAL;
	/* Contents of linux creds are all host-endian: */
	memcpy(res, p, sizeof(u32));
	return 0;
}

static int gssx_dec_linux_creds(struct xdr_stream *xdr,
				struct svc_cred *creds)
{
	u32 length;
	__be32 *p;
	u32 tmp;