kernel-ark/include/linux/sunrpc/xdr.h
Jeff Layton 4c190e2f91 sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer
When GSSAPI integrity signatures are in use, or when we're using GSSAPI
privacy with the v2 token format, there is a trailing checksum on the
xdr_buf that is returned.

It's checked during the authentication stage, and afterward nothing
cares about it. Ordinarily, it's not a problem since the XDR code
generally ignores it, but it will be when we try to compute a checksum
over the buffer to help prevent XID collisions in the duplicate reply
cache.

Fix the code to trim off the checksums after verifying them. Note that
in unwrap_integ_data, we must avoid trying to reverify the checksum if
the request was deferred since it will no longer be present when it's
revisited.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2013-02-08 15:19:10 -05:00

233 lines
7.8 KiB
C

/*
* XDR standard data types and function declarations
*
* Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
*
* Based on:
* RFC 4506 "XDR: External Data Representation Standard", May 2006
*/
#ifndef _SUNRPC_XDR_H_
#define _SUNRPC_XDR_H_
#ifdef __KERNEL__
#include <linux/uio.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/scatterlist.h>
/*
* Buffer adjustment
*/
#define XDR_QUADLEN(l) (((l) + 3) >> 2)
/*
* Generic opaque `network object.' At the kernel level, this type
* is used only by lockd.
*/
#define XDR_MAX_NETOBJ 1024
struct xdr_netobj {
unsigned int len;
u8 * data;
};
/*
* This is the legacy generic XDR function. rqstp is either a rpc_rqst
* (client side) or svc_rqst pointer (server side).
* Encode functions always assume there's enough room in the buffer.
*/
typedef int (*kxdrproc_t)(void *rqstp, __be32 *data, void *obj);
/*
* Basic structure for transmission/reception of a client XDR message.
* Features a header (for a linear buffer containing RPC headers
* and the data payload for short messages), and then an array of
* pages.
* The tail iovec allows you to append data after the page array. Its
* main interest is for appending padding to the pages in order to
* satisfy the int_32-alignment requirements in RFC1832.
*
* For the future, we might want to string several of these together
* in a list if anybody wants to make use of NFSv4 COMPOUND
* operations and/or has a need for scatter/gather involving pages.
*/
struct xdr_buf {
struct kvec head[1], /* RPC header + non-page data */
tail[1]; /* Appended after page data */
struct page ** pages; /* Array of pages */
unsigned int page_base, /* Start of page data */
page_len, /* Length of page data */
flags; /* Flags for data disposition */
#define XDRBUF_READ 0x01 /* target of file read */
#define XDRBUF_WRITE 0x02 /* source of file write */
unsigned int buflen, /* Total length of storage buffer */
len; /* Length of XDR encoded message */
};
/*
* pre-xdr'ed macros.
*/
#define xdr_zero cpu_to_be32(0)
#define xdr_one cpu_to_be32(1)
#define xdr_two cpu_to_be32(2)
#define rpc_success cpu_to_be32(RPC_SUCCESS)
#define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL)
#define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH)
#define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL)
#define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS)
#define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR)
#define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY)
#define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK)
#define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED)
#define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
#define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF)
#define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
#define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK)
#define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
#define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
#define rpc_autherr_oldseqnum cpu_to_be32(101)
/*
* Miscellaneous XDR helper functions
*/
__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
__be32 *xdr_encode_string(__be32 *p, const char *s);
__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
unsigned int maxlen);
__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
void xdr_inline_pages(struct xdr_buf *, unsigned int,
struct page **, unsigned int, unsigned int);
void xdr_terminate_string(struct xdr_buf *, const u32);
static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
{
return xdr_encode_opaque(p, s, len);
}
/*
* Decode 64bit quantities (NFSv3 support)
*/
static inline __be32 *
xdr_encode_hyper(__be32 *p, __u64 val)
{
put_unaligned_be64(val, p);
return p + 2;
}
static inline __be32 *
xdr_decode_hyper(__be32 *p, __u64 *valp)
{
*valp = get_unaligned_be64(p);
return p + 2;
}
static inline __be32 *
xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
{
memcpy(ptr, p, len);
return p + XDR_QUADLEN(len);
}
/*
* Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
*/
static inline int
xdr_adjust_iovec(struct kvec *iov, __be32 *p)
{
return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
}
/*
* XDR buffer helper functions
*/
extern void xdr_shift_buf(struct xdr_buf *, size_t);
extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
/*
* Helper structure for copying from an sk_buff.
*/
struct xdr_skb_reader {
struct sk_buff *skb;
unsigned int offset;
size_t count;
__wsum csum;
};
typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
struct xdr_skb_reader *, xdr_skb_read_actor);
extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
struct xdr_array2_desc;
typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
struct xdr_array2_desc {
unsigned int elem_size;
unsigned int array_len;
unsigned int array_maxlen;
xdr_xcode_elem_t xcode;
};
extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
struct xdr_array2_desc *desc);
extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
struct xdr_array2_desc *desc);
extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
size_t len);
/*
* Provide some simple tools for XDR buffer overflow-checking etc.
*/
struct xdr_stream {
__be32 *p; /* start of available buffer */
struct xdr_buf *buf; /* XDR buffer to read/write */
__be32 *end; /* end of available buffer space */
struct kvec *iov; /* pointer to the current kvec */
struct kvec scratch; /* Scratch buffer */
struct page **page_ptr; /* pointer to the current page */
unsigned int nwords; /* Remaining decode buffer length */
};
/*
* These are the xdr_stream style generic XDR encode and decode functions.
*/
typedef void (*kxdreproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
typedef int (*kxdrdproc_t)(void *rqstp, struct xdr_stream *xdr, void *obj);
extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
unsigned int base, unsigned int len);
extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
struct page **pages, unsigned int len);
extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
#endif /* __KERNEL__ */
#endif /* _SUNRPC_XDR_H_ */