/* SPDX-License-Identifier: GPL-2.0 */ /* * XDR standard data types and function declarations * * Copyright (C) 1995-1997 Olaf Kirch * * Based on: * RFC 4506 "XDR: External Data Representation Standard", May 2006 */ #ifndef _SUNRPC_XDR_H_ #define _SUNRPC_XDR_H_ #ifdef __KERNEL__ #include #include #include #include struct rpc_rqst; /* * Buffer adjustment */ #define XDR_QUADLEN(l) (((l) + 3) >> 2) /* * Generic opaque `network object.' */ #define XDR_MAX_NETOBJ 1024 struct xdr_netobj { unsigned int len; u8 * data; }; /* * 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 */ }; static inline void xdr_buf_init(struct xdr_buf *buf, void *start, size_t len) { buf->head[0].iov_base = start; buf->head[0].iov_len = len; buf->tail[0].iov_len = 0; buf->page_len = 0; buf->flags = 0; buf->len = 0; buf->buflen = len; } /* * 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)(struct rpc_rqst *rqstp, struct xdr_stream *xdr, const void *obj); typedef int (*kxdrdproc_t)(struct rpc_rqst *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_commit_encode(struct xdr_stream *xdr); extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len); extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen); 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); /** * xdr_stream_remaining - Return the number of bytes remaining in the stream * @xdr: pointer to struct xdr_stream * * Return value: * Number of bytes remaining in @xdr before xdr->end */ static inline size_t xdr_stream_remaining(const struct xdr_stream *xdr) { return xdr->nwords << 2; } ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, size_t maxlen, gfp_t gfp_flags); /** * xdr_align_size - Calculate padded size of an object * @n: Size of an object being XDR encoded (in bytes) * * Return value: * Size (in bytes) of the object including xdr padding */ static inline size_t xdr_align_size(size_t n) { const size_t mask = sizeof(__u32) - 1; return (n + mask) & ~mask; } /** * xdr_stream_encode_u32 - Encode a 32-bit integer * @xdr: pointer to xdr_stream * @n: integer to encode * * Return values: * On success, returns length in bytes of XDR buffer consumed * %-EMSGSIZE on XDR buffer overflow */ static inline ssize_t xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n) { const size_t len = sizeof(n); __be32 *p = xdr_reserve_space(xdr, len); if (unlikely(!p)) return -EMSGSIZE; *p = cpu_to_be32(n); return len; } /** * xdr_stream_encode_u64 - Encode a 64-bit integer * @xdr: pointer to xdr_stream * @n: 64-bit integer to encode * * Return values: * On success, returns length in bytes of XDR buffer consumed * %-EMSGSIZE on XDR buffer overflow */ static inline ssize_t xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n) { const size_t len = sizeof(n); __be32 *p = xdr_reserve_space(xdr, len); if (unlikely(!p)) return -EMSGSIZE; xdr_encode_hyper(p, n); return len; } /** * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data * @xdr: pointer to xdr_stream * @ptr: pointer to opaque data object * @len: size of object pointed to by @ptr * * Return values: * On success, returns length in bytes of XDR buffer consumed * %-EMSGSIZE on XDR buffer overflow */ static inline ssize_t xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len) { __be32 *p = xdr_reserve_space(xdr, len); if (unlikely(!p)) return -EMSGSIZE; xdr_encode_opaque_fixed(p, ptr, len); return xdr_align_size(len); } /** * xdr_stream_encode_opaque - Encode variable length opaque xdr data * @xdr: pointer to xdr_stream * @ptr: pointer to opaque data object * @len: size of object pointed to by @ptr * * Return values: * On success, returns length in bytes of XDR buffer consumed * %-EMSGSIZE on XDR buffer overflow */ static inline ssize_t xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len) { size_t count = sizeof(__u32) + xdr_align_size(len); __be32 *p = xdr_reserve_space(xdr, count); if (unlikely(!p)) return -EMSGSIZE; xdr_encode_opaque(p, ptr, len); return count; } /** * xdr_stream_decode_u32 - Decode a 32-bit integer * @xdr: pointer to xdr_stream * @ptr: location to store integer * * Return values: * %0 on success * %-EBADMSG on XDR buffer overflow */ static inline ssize_t xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr) { const size_t count = sizeof(*ptr); __be32 *p = xdr_inline_decode(xdr, count); if (unlikely(!p)) return -EBADMSG; *ptr = be32_to_cpup(p); return 0; } /** * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data * @xdr: pointer to xdr_stream * @ptr: location to store data * @len: size of buffer pointed to by @ptr * * Return values: * On success, returns size of object stored in @ptr * %-EBADMSG on XDR buffer overflow */ static inline ssize_t xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len) { __be32 *p = xdr_inline_decode(xdr, len); if (unlikely(!p)) return -EBADMSG; xdr_decode_opaque_fixed(p, ptr, len); return len; } /** * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data * @xdr: pointer to xdr_stream * @ptr: location to store pointer to opaque data * @maxlen: maximum acceptable object size * * Note: the pointer stored in @ptr cannot be assumed valid after the XDR * buffer has been destroyed, or even after calling xdr_inline_decode() * on @xdr. It is therefore expected that the object it points to should * be processed immediately. * * Return values: * On success, returns size of object stored in *@ptr * %-EBADMSG on XDR buffer overflow * %-EMSGSIZE if the size of the object would exceed @maxlen */ static inline ssize_t xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen) { __be32 *p; __u32 len; *ptr = NULL; if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0)) return -EBADMSG; if (len != 0) { p = xdr_inline_decode(xdr, len); if (unlikely(!p)) return -EBADMSG; if (unlikely(len > maxlen)) return -EMSGSIZE; *ptr = p; } return len; } #endif /* __KERNEL__ */ #endif /* _SUNRPC_XDR_H_ */