mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Chuck Lever](/assets/img/avatar_default.png)
xdr_stream_subsegment() was introduced in commit c1346a1216
("NFSD: Replace the internals of the READ_BUF() macro").
There are two call sites for xdr_stream_subsegment(). One is
nfsd4_decode_write(), and the other is nfsd4_decode_setxattr().
Currently neither of these call sites calls this API when
xdr_buf::page_base is a non-zero value.
However, I'm about to add a case where page_base will sometimes not
be zero when nfsd4_decode_write() invokes this API. Replace the
logic in xdr_stream_subsegment() that advances to the next data item
in the xdr_stream with something more generic in order to handle
this new use case.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2195 lines
55 KiB
C
2195 lines
55 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* linux/net/sunrpc/xdr.c
|
|
*
|
|
* Generic XDR support.
|
|
*
|
|
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/types.h>
|
|
#include <linux/string.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/sunrpc/xdr.h>
|
|
#include <linux/sunrpc/msg_prot.h>
|
|
#include <linux/bvec.h>
|
|
#include <trace/events/sunrpc.h>
|
|
|
|
static void _copy_to_pages(struct page **, size_t, const char *, size_t);
|
|
|
|
|
|
/*
|
|
* XDR functions for basic NFS types
|
|
*/
|
|
__be32 *
|
|
xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj)
|
|
{
|
|
unsigned int quadlen = XDR_QUADLEN(obj->len);
|
|
|
|
p[quadlen] = 0; /* zero trailing bytes */
|
|
*p++ = cpu_to_be32(obj->len);
|
|
memcpy(p, obj->data, obj->len);
|
|
return p + XDR_QUADLEN(obj->len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_encode_netobj);
|
|
|
|
__be32 *
|
|
xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj)
|
|
{
|
|
unsigned int len;
|
|
|
|
if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ)
|
|
return NULL;
|
|
obj->len = len;
|
|
obj->data = (u8 *) p;
|
|
return p + XDR_QUADLEN(len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_decode_netobj);
|
|
|
|
/**
|
|
* xdr_encode_opaque_fixed - Encode fixed length opaque data
|
|
* @p: pointer to current position in XDR buffer.
|
|
* @ptr: pointer to data to encode (or NULL)
|
|
* @nbytes: size of data.
|
|
*
|
|
* Copy the array of data of length nbytes at ptr to the XDR buffer
|
|
* at position p, then align to the next 32-bit boundary by padding
|
|
* with zero bytes (see RFC1832).
|
|
* Note: if ptr is NULL, only the padding is performed.
|
|
*
|
|
* Returns the updated current XDR buffer position
|
|
*
|
|
*/
|
|
__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes)
|
|
{
|
|
if (likely(nbytes != 0)) {
|
|
unsigned int quadlen = XDR_QUADLEN(nbytes);
|
|
unsigned int padding = (quadlen << 2) - nbytes;
|
|
|
|
if (ptr != NULL)
|
|
memcpy(p, ptr, nbytes);
|
|
if (padding != 0)
|
|
memset((char *)p + nbytes, 0, padding);
|
|
p += quadlen;
|
|
}
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed);
|
|
|
|
/**
|
|
* xdr_encode_opaque - Encode variable length opaque data
|
|
* @p: pointer to current position in XDR buffer.
|
|
* @ptr: pointer to data to encode (or NULL)
|
|
* @nbytes: size of data.
|
|
*
|
|
* Returns the updated current XDR buffer position
|
|
*/
|
|
__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes)
|
|
{
|
|
*p++ = cpu_to_be32(nbytes);
|
|
return xdr_encode_opaque_fixed(p, ptr, nbytes);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_encode_opaque);
|
|
|
|
__be32 *
|
|
xdr_encode_string(__be32 *p, const char *string)
|
|
{
|
|
return xdr_encode_array(p, string, strlen(string));
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_encode_string);
|
|
|
|
__be32 *
|
|
xdr_decode_string_inplace(__be32 *p, char **sp,
|
|
unsigned int *lenp, unsigned int maxlen)
|
|
{
|
|
u32 len;
|
|
|
|
len = be32_to_cpu(*p++);
|
|
if (len > maxlen)
|
|
return NULL;
|
|
*lenp = len;
|
|
*sp = (char *) p;
|
|
return p + XDR_QUADLEN(len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_decode_string_inplace);
|
|
|
|
/**
|
|
* xdr_terminate_string - '\0'-terminate a string residing in an xdr_buf
|
|
* @buf: XDR buffer where string resides
|
|
* @len: length of string, in bytes
|
|
*
|
|
*/
|
|
void xdr_terminate_string(const struct xdr_buf *buf, const u32 len)
|
|
{
|
|
char *kaddr;
|
|
|
|
kaddr = kmap_atomic(buf->pages[0]);
|
|
kaddr[buf->page_base + len] = '\0';
|
|
kunmap_atomic(kaddr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_terminate_string);
|
|
|
|
size_t xdr_buf_pagecount(const struct xdr_buf *buf)
|
|
{
|
|
if (!buf->page_len)
|
|
return 0;
|
|
return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
}
|
|
|
|
int
|
|
xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp)
|
|
{
|
|
size_t i, n = xdr_buf_pagecount(buf);
|
|
|
|
if (n != 0 && buf->bvec == NULL) {
|
|
buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp);
|
|
if (!buf->bvec)
|
|
return -ENOMEM;
|
|
for (i = 0; i < n; i++) {
|
|
buf->bvec[i].bv_page = buf->pages[i];
|
|
buf->bvec[i].bv_len = PAGE_SIZE;
|
|
buf->bvec[i].bv_offset = 0;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
xdr_free_bvec(struct xdr_buf *buf)
|
|
{
|
|
kfree(buf->bvec);
|
|
buf->bvec = NULL;
|
|
}
|
|
|
|
/**
|
|
* xdr_inline_pages - Prepare receive buffer for a large reply
|
|
* @xdr: xdr_buf into which reply will be placed
|
|
* @offset: expected offset where data payload will start, in bytes
|
|
* @pages: vector of struct page pointers
|
|
* @base: offset in first page where receive should start, in bytes
|
|
* @len: expected size of the upper layer data payload, in bytes
|
|
*
|
|
*/
|
|
void
|
|
xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
|
|
struct page **pages, unsigned int base, unsigned int len)
|
|
{
|
|
struct kvec *head = xdr->head;
|
|
struct kvec *tail = xdr->tail;
|
|
char *buf = (char *)head->iov_base;
|
|
unsigned int buflen = head->iov_len;
|
|
|
|
head->iov_len = offset;
|
|
|
|
xdr->pages = pages;
|
|
xdr->page_base = base;
|
|
xdr->page_len = len;
|
|
|
|
tail->iov_base = buf + offset;
|
|
tail->iov_len = buflen - offset;
|
|
xdr->buflen += len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_inline_pages);
|
|
|
|
/*
|
|
* Helper routines for doing 'memmove' like operations on a struct xdr_buf
|
|
*/
|
|
|
|
/**
|
|
* _shift_data_left_pages
|
|
* @pages: vector of pages containing both the source and dest memory area.
|
|
* @pgto_base: page vector address of destination
|
|
* @pgfrom_base: page vector address of source
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Note: the addresses pgto_base and pgfrom_base are both calculated in
|
|
* the same way:
|
|
* if a memory area starts at byte 'base' in page 'pages[i]',
|
|
* then its address is given as (i << PAGE_CACHE_SHIFT) + base
|
|
* Alse note: pgto_base must be < pgfrom_base, but the memory areas
|
|
* they point to may overlap.
|
|
*/
|
|
static void
|
|
_shift_data_left_pages(struct page **pages, size_t pgto_base,
|
|
size_t pgfrom_base, size_t len)
|
|
{
|
|
struct page **pgfrom, **pgto;
|
|
char *vfrom, *vto;
|
|
size_t copy;
|
|
|
|
BUG_ON(pgfrom_base <= pgto_base);
|
|
|
|
if (!len)
|
|
return;
|
|
|
|
pgto = pages + (pgto_base >> PAGE_SHIFT);
|
|
pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
|
|
|
|
pgto_base &= ~PAGE_MASK;
|
|
pgfrom_base &= ~PAGE_MASK;
|
|
|
|
do {
|
|
if (pgto_base >= PAGE_SIZE) {
|
|
pgto_base = 0;
|
|
pgto++;
|
|
}
|
|
if (pgfrom_base >= PAGE_SIZE){
|
|
pgfrom_base = 0;
|
|
pgfrom++;
|
|
}
|
|
|
|
copy = len;
|
|
if (copy > (PAGE_SIZE - pgto_base))
|
|
copy = PAGE_SIZE - pgto_base;
|
|
if (copy > (PAGE_SIZE - pgfrom_base))
|
|
copy = PAGE_SIZE - pgfrom_base;
|
|
|
|
vto = kmap_atomic(*pgto);
|
|
if (*pgto != *pgfrom) {
|
|
vfrom = kmap_atomic(*pgfrom);
|
|
memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
|
|
kunmap_atomic(vfrom);
|
|
} else
|
|
memmove(vto + pgto_base, vto + pgfrom_base, copy);
|
|
flush_dcache_page(*pgto);
|
|
kunmap_atomic(vto);
|
|
|
|
pgto_base += copy;
|
|
pgfrom_base += copy;
|
|
|
|
} while ((len -= copy) != 0);
|
|
}
|
|
|
|
/**
|
|
* _shift_data_right_pages
|
|
* @pages: vector of pages containing both the source and dest memory area.
|
|
* @pgto_base: page vector address of destination
|
|
* @pgfrom_base: page vector address of source
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Note: the addresses pgto_base and pgfrom_base are both calculated in
|
|
* the same way:
|
|
* if a memory area starts at byte 'base' in page 'pages[i]',
|
|
* then its address is given as (i << PAGE_SHIFT) + base
|
|
* Also note: pgfrom_base must be < pgto_base, but the memory areas
|
|
* they point to may overlap.
|
|
*/
|
|
static void
|
|
_shift_data_right_pages(struct page **pages, size_t pgto_base,
|
|
size_t pgfrom_base, size_t len)
|
|
{
|
|
struct page **pgfrom, **pgto;
|
|
char *vfrom, *vto;
|
|
size_t copy;
|
|
|
|
BUG_ON(pgto_base <= pgfrom_base);
|
|
|
|
if (!len)
|
|
return;
|
|
|
|
pgto_base += len;
|
|
pgfrom_base += len;
|
|
|
|
pgto = pages + (pgto_base >> PAGE_SHIFT);
|
|
pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
|
|
|
|
pgto_base &= ~PAGE_MASK;
|
|
pgfrom_base &= ~PAGE_MASK;
|
|
|
|
do {
|
|
/* Are any pointers crossing a page boundary? */
|
|
if (pgto_base == 0) {
|
|
pgto_base = PAGE_SIZE;
|
|
pgto--;
|
|
}
|
|
if (pgfrom_base == 0) {
|
|
pgfrom_base = PAGE_SIZE;
|
|
pgfrom--;
|
|
}
|
|
|
|
copy = len;
|
|
if (copy > pgto_base)
|
|
copy = pgto_base;
|
|
if (copy > pgfrom_base)
|
|
copy = pgfrom_base;
|
|
pgto_base -= copy;
|
|
pgfrom_base -= copy;
|
|
|
|
vto = kmap_atomic(*pgto);
|
|
if (*pgto != *pgfrom) {
|
|
vfrom = kmap_atomic(*pgfrom);
|
|
memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
|
|
kunmap_atomic(vfrom);
|
|
} else
|
|
memmove(vto + pgto_base, vto + pgfrom_base, copy);
|
|
flush_dcache_page(*pgto);
|
|
kunmap_atomic(vto);
|
|
|
|
} while ((len -= copy) != 0);
|
|
}
|
|
|
|
/**
|
|
* _copy_to_pages
|
|
* @pages: array of pages
|
|
* @pgbase: page vector address of destination
|
|
* @p: pointer to source data
|
|
* @len: length
|
|
*
|
|
* Copies data from an arbitrary memory location into an array of pages
|
|
* The copy is assumed to be non-overlapping.
|
|
*/
|
|
static void
|
|
_copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
|
|
{
|
|
struct page **pgto;
|
|
char *vto;
|
|
size_t copy;
|
|
|
|
if (!len)
|
|
return;
|
|
|
|
pgto = pages + (pgbase >> PAGE_SHIFT);
|
|
pgbase &= ~PAGE_MASK;
|
|
|
|
for (;;) {
|
|
copy = PAGE_SIZE - pgbase;
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
vto = kmap_atomic(*pgto);
|
|
memcpy(vto + pgbase, p, copy);
|
|
kunmap_atomic(vto);
|
|
|
|
len -= copy;
|
|
if (len == 0)
|
|
break;
|
|
|
|
pgbase += copy;
|
|
if (pgbase == PAGE_SIZE) {
|
|
flush_dcache_page(*pgto);
|
|
pgbase = 0;
|
|
pgto++;
|
|
}
|
|
p += copy;
|
|
}
|
|
flush_dcache_page(*pgto);
|
|
}
|
|
|
|
/**
|
|
* _copy_from_pages
|
|
* @p: pointer to destination
|
|
* @pages: array of pages
|
|
* @pgbase: offset of source data
|
|
* @len: length
|
|
*
|
|
* Copies data into an arbitrary memory location from an array of pages
|
|
* The copy is assumed to be non-overlapping.
|
|
*/
|
|
void
|
|
_copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
|
|
{
|
|
struct page **pgfrom;
|
|
char *vfrom;
|
|
size_t copy;
|
|
|
|
if (!len)
|
|
return;
|
|
|
|
pgfrom = pages + (pgbase >> PAGE_SHIFT);
|
|
pgbase &= ~PAGE_MASK;
|
|
|
|
do {
|
|
copy = PAGE_SIZE - pgbase;
|
|
if (copy > len)
|
|
copy = len;
|
|
|
|
vfrom = kmap_atomic(*pgfrom);
|
|
memcpy(p, vfrom + pgbase, copy);
|
|
kunmap_atomic(vfrom);
|
|
|
|
pgbase += copy;
|
|
if (pgbase == PAGE_SIZE) {
|
|
pgbase = 0;
|
|
pgfrom++;
|
|
}
|
|
p += copy;
|
|
|
|
} while ((len -= copy) != 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(_copy_from_pages);
|
|
|
|
static void xdr_buf_iov_zero(const struct kvec *iov, unsigned int base,
|
|
unsigned int len)
|
|
{
|
|
if (base >= iov->iov_len)
|
|
return;
|
|
if (len > iov->iov_len - base)
|
|
len = iov->iov_len - base;
|
|
memset(iov->iov_base + base, 0, len);
|
|
}
|
|
|
|
/**
|
|
* xdr_buf_pages_zero
|
|
* @buf: xdr_buf
|
|
* @pgbase: beginning offset
|
|
* @len: length
|
|
*/
|
|
static void xdr_buf_pages_zero(const struct xdr_buf *buf, unsigned int pgbase,
|
|
unsigned int len)
|
|
{
|
|
struct page **pages = buf->pages;
|
|
struct page **page;
|
|
char *vpage;
|
|
unsigned int zero;
|
|
|
|
if (!len)
|
|
return;
|
|
if (pgbase >= buf->page_len) {
|
|
xdr_buf_iov_zero(buf->tail, pgbase - buf->page_len, len);
|
|
return;
|
|
}
|
|
if (pgbase + len > buf->page_len) {
|
|
xdr_buf_iov_zero(buf->tail, 0, pgbase + len - buf->page_len);
|
|
len = buf->page_len - pgbase;
|
|
}
|
|
|
|
pgbase += buf->page_base;
|
|
|
|
page = pages + (pgbase >> PAGE_SHIFT);
|
|
pgbase &= ~PAGE_MASK;
|
|
|
|
do {
|
|
zero = PAGE_SIZE - pgbase;
|
|
if (zero > len)
|
|
zero = len;
|
|
|
|
vpage = kmap_atomic(*page);
|
|
memset(vpage + pgbase, 0, zero);
|
|
kunmap_atomic(vpage);
|
|
|
|
flush_dcache_page(*page);
|
|
pgbase = 0;
|
|
page++;
|
|
|
|
} while ((len -= zero) != 0);
|
|
}
|
|
|
|
static unsigned int xdr_buf_pages_fill_sparse(const struct xdr_buf *buf,
|
|
unsigned int buflen, gfp_t gfp)
|
|
{
|
|
unsigned int i, npages, pagelen;
|
|
|
|
if (!(buf->flags & XDRBUF_SPARSE_PAGES))
|
|
return buflen;
|
|
if (buflen <= buf->head->iov_len)
|
|
return buflen;
|
|
pagelen = buflen - buf->head->iov_len;
|
|
if (pagelen > buf->page_len)
|
|
pagelen = buf->page_len;
|
|
npages = (pagelen + buf->page_base + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
for (i = 0; i < npages; i++) {
|
|
if (!buf->pages[i])
|
|
continue;
|
|
buf->pages[i] = alloc_page(gfp);
|
|
if (likely(buf->pages[i]))
|
|
continue;
|
|
buflen -= pagelen;
|
|
pagelen = i << PAGE_SHIFT;
|
|
if (pagelen > buf->page_base)
|
|
buflen += pagelen - buf->page_base;
|
|
break;
|
|
}
|
|
return buflen;
|
|
}
|
|
|
|
static void xdr_buf_try_expand(struct xdr_buf *buf, unsigned int len)
|
|
{
|
|
struct kvec *head = buf->head;
|
|
struct kvec *tail = buf->tail;
|
|
unsigned int sum = head->iov_len + buf->page_len + tail->iov_len;
|
|
unsigned int free_space, newlen;
|
|
|
|
if (sum > buf->len) {
|
|
free_space = min_t(unsigned int, sum - buf->len, len);
|
|
newlen = xdr_buf_pages_fill_sparse(buf, buf->len + free_space,
|
|
GFP_KERNEL);
|
|
free_space = newlen - buf->len;
|
|
buf->len = newlen;
|
|
len -= free_space;
|
|
if (!len)
|
|
return;
|
|
}
|
|
|
|
if (buf->buflen > sum) {
|
|
/* Expand the tail buffer */
|
|
free_space = min_t(unsigned int, buf->buflen - sum, len);
|
|
tail->iov_len += free_space;
|
|
buf->len += free_space;
|
|
}
|
|
}
|
|
|
|
static void xdr_buf_tail_copy_right(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
const struct kvec *tail = buf->tail;
|
|
unsigned int to = base + shift;
|
|
|
|
if (to >= tail->iov_len)
|
|
return;
|
|
if (len + to > tail->iov_len)
|
|
len = tail->iov_len - to;
|
|
memmove(tail->iov_base + to, tail->iov_base + base, len);
|
|
}
|
|
|
|
static void xdr_buf_pages_copy_right(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
const struct kvec *tail = buf->tail;
|
|
unsigned int to = base + shift;
|
|
unsigned int pglen = 0;
|
|
unsigned int talen = 0, tato = 0;
|
|
|
|
if (base >= buf->page_len)
|
|
return;
|
|
if (len > buf->page_len - base)
|
|
len = buf->page_len - base;
|
|
if (to >= buf->page_len) {
|
|
tato = to - buf->page_len;
|
|
if (tail->iov_len >= len + tato)
|
|
talen = len;
|
|
else if (tail->iov_len > tato)
|
|
talen = tail->iov_len - tato;
|
|
} else if (len + to >= buf->page_len) {
|
|
pglen = buf->page_len - to;
|
|
talen = len - pglen;
|
|
if (talen > tail->iov_len)
|
|
talen = tail->iov_len;
|
|
} else
|
|
pglen = len;
|
|
|
|
_copy_from_pages(tail->iov_base + tato, buf->pages,
|
|
buf->page_base + base + pglen, talen);
|
|
_shift_data_right_pages(buf->pages, buf->page_base + to,
|
|
buf->page_base + base, pglen);
|
|
}
|
|
|
|
static void xdr_buf_head_copy_right(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
const struct kvec *head = buf->head;
|
|
const struct kvec *tail = buf->tail;
|
|
unsigned int to = base + shift;
|
|
unsigned int pglen = 0, pgto = 0;
|
|
unsigned int talen = 0, tato = 0;
|
|
|
|
if (base >= head->iov_len)
|
|
return;
|
|
if (len > head->iov_len - base)
|
|
len = head->iov_len - base;
|
|
if (to >= buf->page_len + head->iov_len) {
|
|
tato = to - buf->page_len - head->iov_len;
|
|
talen = len;
|
|
} else if (to >= head->iov_len) {
|
|
pgto = to - head->iov_len;
|
|
pglen = len;
|
|
if (pgto + pglen > buf->page_len) {
|
|
talen = pgto + pglen - buf->page_len;
|
|
pglen -= talen;
|
|
}
|
|
} else {
|
|
pglen = len - to;
|
|
if (pglen > buf->page_len) {
|
|
talen = pglen - buf->page_len;
|
|
pglen = buf->page_len;
|
|
}
|
|
}
|
|
|
|
len -= talen;
|
|
base += len;
|
|
if (talen + tato > tail->iov_len)
|
|
talen = tail->iov_len > tato ? tail->iov_len - tato : 0;
|
|
memcpy(tail->iov_base + tato, head->iov_base + base, talen);
|
|
|
|
len -= pglen;
|
|
base -= pglen;
|
|
_copy_to_pages(buf->pages, buf->page_base + pgto, head->iov_base + base,
|
|
pglen);
|
|
|
|
base -= len;
|
|
memmove(head->iov_base + to, head->iov_base + base, len);
|
|
}
|
|
|
|
static void xdr_buf_tail_shift_right(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
const struct kvec *tail = buf->tail;
|
|
|
|
if (base >= tail->iov_len || !shift || !len)
|
|
return;
|
|
xdr_buf_tail_copy_right(buf, base, len, shift);
|
|
}
|
|
|
|
static void xdr_buf_pages_shift_right(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
if (!shift || !len)
|
|
return;
|
|
if (base >= buf->page_len) {
|
|
xdr_buf_tail_shift_right(buf, base - buf->page_len, len, shift);
|
|
return;
|
|
}
|
|
if (base + len > buf->page_len)
|
|
xdr_buf_tail_shift_right(buf, 0, base + len - buf->page_len,
|
|
shift);
|
|
xdr_buf_pages_copy_right(buf, base, len, shift);
|
|
}
|
|
|
|
static void xdr_buf_head_shift_right(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
const struct kvec *head = buf->head;
|
|
|
|
if (!shift)
|
|
return;
|
|
if (base >= head->iov_len) {
|
|
xdr_buf_pages_shift_right(buf, head->iov_len - base, len,
|
|
shift);
|
|
return;
|
|
}
|
|
if (base + len > head->iov_len)
|
|
xdr_buf_pages_shift_right(buf, 0, base + len - head->iov_len,
|
|
shift);
|
|
xdr_buf_head_copy_right(buf, base, len, shift);
|
|
}
|
|
|
|
static void xdr_buf_tail_copy_left(const struct xdr_buf *buf, unsigned int base,
|
|
unsigned int len, unsigned int shift)
|
|
{
|
|
const struct kvec *tail = buf->tail;
|
|
|
|
if (base >= tail->iov_len)
|
|
return;
|
|
if (len > tail->iov_len - base)
|
|
len = tail->iov_len - base;
|
|
/* Shift data into head */
|
|
if (shift > buf->page_len + base) {
|
|
const struct kvec *head = buf->head;
|
|
unsigned int hdto =
|
|
head->iov_len + buf->page_len + base - shift;
|
|
unsigned int hdlen = len;
|
|
|
|
if (WARN_ONCE(shift > head->iov_len + buf->page_len + base,
|
|
"SUNRPC: Misaligned data.\n"))
|
|
return;
|
|
if (hdto + hdlen > head->iov_len)
|
|
hdlen = head->iov_len - hdto;
|
|
memcpy(head->iov_base + hdto, tail->iov_base + base, hdlen);
|
|
base += hdlen;
|
|
len -= hdlen;
|
|
if (!len)
|
|
return;
|
|
}
|
|
/* Shift data into pages */
|
|
if (shift > base) {
|
|
unsigned int pgto = buf->page_len + base - shift;
|
|
unsigned int pglen = len;
|
|
|
|
if (pgto + pglen > buf->page_len)
|
|
pglen = buf->page_len - pgto;
|
|
_copy_to_pages(buf->pages, buf->page_base + pgto,
|
|
tail->iov_base + base, pglen);
|
|
base += pglen;
|
|
len -= pglen;
|
|
if (!len)
|
|
return;
|
|
}
|
|
memmove(tail->iov_base + base - shift, tail->iov_base + base, len);
|
|
}
|
|
|
|
static void xdr_buf_pages_copy_left(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
unsigned int pgto;
|
|
|
|
if (base >= buf->page_len)
|
|
return;
|
|
if (len > buf->page_len - base)
|
|
len = buf->page_len - base;
|
|
/* Shift data into head */
|
|
if (shift > base) {
|
|
const struct kvec *head = buf->head;
|
|
unsigned int hdto = head->iov_len + base - shift;
|
|
unsigned int hdlen = len;
|
|
|
|
if (WARN_ONCE(shift > head->iov_len + base,
|
|
"SUNRPC: Misaligned data.\n"))
|
|
return;
|
|
if (hdto + hdlen > head->iov_len)
|
|
hdlen = head->iov_len - hdto;
|
|
_copy_from_pages(head->iov_base + hdto, buf->pages,
|
|
buf->page_base + base, hdlen);
|
|
base += hdlen;
|
|
len -= hdlen;
|
|
if (!len)
|
|
return;
|
|
}
|
|
pgto = base - shift;
|
|
_shift_data_left_pages(buf->pages, buf->page_base + pgto,
|
|
buf->page_base + base, len);
|
|
}
|
|
|
|
static void xdr_buf_tail_shift_left(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
if (!shift || !len)
|
|
return;
|
|
xdr_buf_tail_copy_left(buf, base, len, shift);
|
|
}
|
|
|
|
static void xdr_buf_pages_shift_left(const struct xdr_buf *buf,
|
|
unsigned int base, unsigned int len,
|
|
unsigned int shift)
|
|
{
|
|
if (!shift || !len)
|
|
return;
|
|
if (base >= buf->page_len) {
|
|
xdr_buf_tail_shift_left(buf, base - buf->page_len, len, shift);
|
|
return;
|
|
}
|
|
xdr_buf_pages_copy_left(buf, base, len, shift);
|
|
len += base;
|
|
if (len <= buf->page_len)
|
|
return;
|
|
xdr_buf_tail_copy_left(buf, 0, len - buf->page_len, shift);
|
|
}
|
|
|
|
/**
|
|
* xdr_shrink_bufhead
|
|
* @buf: xdr_buf
|
|
* @len: new length of buf->head[0]
|
|
*
|
|
* Shrinks XDR buffer's header kvec buf->head[0], setting it to
|
|
* 'len' bytes. The extra data is not lost, but is instead
|
|
* moved into the inlined pages and/or the tail.
|
|
*/
|
|
static unsigned int xdr_shrink_bufhead(struct xdr_buf *buf, unsigned int len)
|
|
{
|
|
struct kvec *head = buf->head;
|
|
unsigned int shift, buflen = max(buf->len, len);
|
|
|
|
WARN_ON_ONCE(len > head->iov_len);
|
|
if (head->iov_len > buflen) {
|
|
buf->buflen -= head->iov_len - buflen;
|
|
head->iov_len = buflen;
|
|
}
|
|
if (len >= head->iov_len)
|
|
return 0;
|
|
shift = head->iov_len - len;
|
|
xdr_buf_try_expand(buf, shift);
|
|
xdr_buf_head_shift_right(buf, len, buflen - len, shift);
|
|
head->iov_len = len;
|
|
buf->buflen -= shift;
|
|
buf->len -= shift;
|
|
return shift;
|
|
}
|
|
|
|
/**
|
|
* xdr_shrink_pagelen - shrinks buf->pages to @len bytes
|
|
* @buf: xdr_buf
|
|
* @len: new page buffer length
|
|
*
|
|
* The extra data is not lost, but is instead moved into buf->tail.
|
|
* Returns the actual number of bytes moved.
|
|
*/
|
|
static unsigned int xdr_shrink_pagelen(struct xdr_buf *buf, unsigned int len)
|
|
{
|
|
unsigned int shift, buflen = buf->len - buf->head->iov_len;
|
|
|
|
WARN_ON_ONCE(len > buf->page_len);
|
|
if (buf->head->iov_len >= buf->len || len > buflen)
|
|
buflen = len;
|
|
if (buf->page_len > buflen) {
|
|
buf->buflen -= buf->page_len - buflen;
|
|
buf->page_len = buflen;
|
|
}
|
|
if (len >= buf->page_len)
|
|
return 0;
|
|
shift = buf->page_len - len;
|
|
xdr_buf_try_expand(buf, shift);
|
|
xdr_buf_pages_shift_right(buf, len, buflen - len, shift);
|
|
buf->page_len = len;
|
|
buf->len -= shift;
|
|
buf->buflen -= shift;
|
|
return shift;
|
|
}
|
|
|
|
void
|
|
xdr_shift_buf(struct xdr_buf *buf, size_t len)
|
|
{
|
|
xdr_shrink_bufhead(buf, buf->head->iov_len - len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_shift_buf);
|
|
|
|
/**
|
|
* xdr_stream_pos - Return the current offset from the start of the xdr_stream
|
|
* @xdr: pointer to struct xdr_stream
|
|
*/
|
|
unsigned int xdr_stream_pos(const struct xdr_stream *xdr)
|
|
{
|
|
return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_stream_pos);
|
|
|
|
static void xdr_stream_set_pos(struct xdr_stream *xdr, unsigned int pos)
|
|
{
|
|
unsigned int blen = xdr->buf->len;
|
|
|
|
xdr->nwords = blen > pos ? XDR_QUADLEN(blen) - XDR_QUADLEN(pos) : 0;
|
|
}
|
|
|
|
static void xdr_stream_page_set_pos(struct xdr_stream *xdr, unsigned int pos)
|
|
{
|
|
xdr_stream_set_pos(xdr, pos + xdr->buf->head[0].iov_len);
|
|
}
|
|
|
|
/**
|
|
* xdr_page_pos - Return the current offset from the start of the xdr pages
|
|
* @xdr: pointer to struct xdr_stream
|
|
*/
|
|
unsigned int xdr_page_pos(const struct xdr_stream *xdr)
|
|
{
|
|
unsigned int pos = xdr_stream_pos(xdr);
|
|
|
|
WARN_ON(pos < xdr->buf->head[0].iov_len);
|
|
return pos - xdr->buf->head[0].iov_len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_page_pos);
|
|
|
|
/**
|
|
* xdr_init_encode - Initialize a struct xdr_stream for sending data.
|
|
* @xdr: pointer to xdr_stream struct
|
|
* @buf: pointer to XDR buffer in which to encode data
|
|
* @p: current pointer inside XDR buffer
|
|
* @rqst: pointer to controlling rpc_rqst, for debugging
|
|
*
|
|
* Note: at the moment the RPC client only passes the length of our
|
|
* scratch buffer in the xdr_buf's header kvec. Previously this
|
|
* meant we needed to call xdr_adjust_iovec() after encoding the
|
|
* data. With the new scheme, the xdr_stream manages the details
|
|
* of the buffer length, and takes care of adjusting the kvec
|
|
* length for us.
|
|
*/
|
|
void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
|
|
struct rpc_rqst *rqst)
|
|
{
|
|
struct kvec *iov = buf->head;
|
|
int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
|
|
|
|
xdr_reset_scratch_buffer(xdr);
|
|
BUG_ON(scratch_len < 0);
|
|
xdr->buf = buf;
|
|
xdr->iov = iov;
|
|
xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len);
|
|
xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len);
|
|
BUG_ON(iov->iov_len > scratch_len);
|
|
|
|
if (p != xdr->p && p != NULL) {
|
|
size_t len;
|
|
|
|
BUG_ON(p < xdr->p || p > xdr->end);
|
|
len = (char *)p - (char *)xdr->p;
|
|
xdr->p = p;
|
|
buf->len += len;
|
|
iov->iov_len += len;
|
|
}
|
|
xdr->rqst = rqst;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_init_encode);
|
|
|
|
/**
|
|
* xdr_commit_encode - Ensure all data is written to buffer
|
|
* @xdr: pointer to xdr_stream
|
|
*
|
|
* We handle encoding across page boundaries by giving the caller a
|
|
* temporary location to write to, then later copying the data into
|
|
* place; xdr_commit_encode does that copying.
|
|
*
|
|
* Normally the caller doesn't need to call this directly, as the
|
|
* following xdr_reserve_space will do it. But an explicit call may be
|
|
* required at the end of encoding, or any other time when the xdr_buf
|
|
* data might be read.
|
|
*/
|
|
inline void xdr_commit_encode(struct xdr_stream *xdr)
|
|
{
|
|
int shift = xdr->scratch.iov_len;
|
|
void *page;
|
|
|
|
if (shift == 0)
|
|
return;
|
|
page = page_address(*xdr->page_ptr);
|
|
memcpy(xdr->scratch.iov_base, page, shift);
|
|
memmove(page, page + shift, (void *)xdr->p - page);
|
|
xdr_reset_scratch_buffer(xdr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_commit_encode);
|
|
|
|
static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr,
|
|
size_t nbytes)
|
|
{
|
|
__be32 *p;
|
|
int space_left;
|
|
int frag1bytes, frag2bytes;
|
|
|
|
if (nbytes > PAGE_SIZE)
|
|
goto out_overflow; /* Bigger buffers require special handling */
|
|
if (xdr->buf->len + nbytes > xdr->buf->buflen)
|
|
goto out_overflow; /* Sorry, we're totally out of space */
|
|
frag1bytes = (xdr->end - xdr->p) << 2;
|
|
frag2bytes = nbytes - frag1bytes;
|
|
if (xdr->iov)
|
|
xdr->iov->iov_len += frag1bytes;
|
|
else
|
|
xdr->buf->page_len += frag1bytes;
|
|
xdr->page_ptr++;
|
|
xdr->iov = NULL;
|
|
/*
|
|
* If the last encode didn't end exactly on a page boundary, the
|
|
* next one will straddle boundaries. Encode into the next
|
|
* page, then copy it back later in xdr_commit_encode. We use
|
|
* the "scratch" iov to track any temporarily unused fragment of
|
|
* space at the end of the previous buffer:
|
|
*/
|
|
xdr_set_scratch_buffer(xdr, xdr->p, frag1bytes);
|
|
p = page_address(*xdr->page_ptr);
|
|
/*
|
|
* Note this is where the next encode will start after we've
|
|
* shifted this one back:
|
|
*/
|
|
xdr->p = (void *)p + frag2bytes;
|
|
space_left = xdr->buf->buflen - xdr->buf->len;
|
|
xdr->end = (void *)p + min_t(int, space_left, PAGE_SIZE);
|
|
xdr->buf->page_len += frag2bytes;
|
|
xdr->buf->len += nbytes;
|
|
return p;
|
|
out_overflow:
|
|
trace_rpc_xdr_overflow(xdr, nbytes);
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* xdr_reserve_space - Reserve buffer space for sending
|
|
* @xdr: pointer to xdr_stream
|
|
* @nbytes: number of bytes to reserve
|
|
*
|
|
* Checks that we have enough buffer space to encode 'nbytes' more
|
|
* bytes of data. If so, update the total xdr_buf length, and
|
|
* adjust the length of the current kvec.
|
|
*/
|
|
__be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
|
|
{
|
|
__be32 *p = xdr->p;
|
|
__be32 *q;
|
|
|
|
xdr_commit_encode(xdr);
|
|
/* align nbytes on the next 32-bit boundary */
|
|
nbytes += 3;
|
|
nbytes &= ~3;
|
|
q = p + (nbytes >> 2);
|
|
if (unlikely(q > xdr->end || q < p))
|
|
return xdr_get_next_encode_buffer(xdr, nbytes);
|
|
xdr->p = q;
|
|
if (xdr->iov)
|
|
xdr->iov->iov_len += nbytes;
|
|
else
|
|
xdr->buf->page_len += nbytes;
|
|
xdr->buf->len += nbytes;
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_reserve_space);
|
|
|
|
|
|
/**
|
|
* xdr_reserve_space_vec - Reserves a large amount of buffer space for sending
|
|
* @xdr: pointer to xdr_stream
|
|
* @vec: pointer to a kvec array
|
|
* @nbytes: number of bytes to reserve
|
|
*
|
|
* Reserves enough buffer space to encode 'nbytes' of data and stores the
|
|
* pointers in 'vec'. The size argument passed to xdr_reserve_space() is
|
|
* determined based on the number of bytes remaining in the current page to
|
|
* avoid invalidating iov_base pointers when xdr_commit_encode() is called.
|
|
*/
|
|
int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbytes)
|
|
{
|
|
int thislen;
|
|
int v = 0;
|
|
__be32 *p;
|
|
|
|
/*
|
|
* svcrdma requires every READ payload to start somewhere
|
|
* in xdr->pages.
|
|
*/
|
|
if (xdr->iov == xdr->buf->head) {
|
|
xdr->iov = NULL;
|
|
xdr->end = xdr->p;
|
|
}
|
|
|
|
while (nbytes) {
|
|
thislen = xdr->buf->page_len % PAGE_SIZE;
|
|
thislen = min_t(size_t, nbytes, PAGE_SIZE - thislen);
|
|
|
|
p = xdr_reserve_space(xdr, thislen);
|
|
if (!p)
|
|
return -EIO;
|
|
|
|
vec[v].iov_base = p;
|
|
vec[v].iov_len = thislen;
|
|
v++;
|
|
nbytes -= thislen;
|
|
}
|
|
|
|
return v;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_reserve_space_vec);
|
|
|
|
/**
|
|
* xdr_truncate_encode - truncate an encode buffer
|
|
* @xdr: pointer to xdr_stream
|
|
* @len: new length of buffer
|
|
*
|
|
* Truncates the xdr stream, so that xdr->buf->len == len,
|
|
* and xdr->p points at offset len from the start of the buffer, and
|
|
* head, tail, and page lengths are adjusted to correspond.
|
|
*
|
|
* If this means moving xdr->p to a different buffer, we assume that
|
|
* the end pointer should be set to the end of the current page,
|
|
* except in the case of the head buffer when we assume the head
|
|
* buffer's current length represents the end of the available buffer.
|
|
*
|
|
* This is *not* safe to use on a buffer that already has inlined page
|
|
* cache pages (as in a zero-copy server read reply), except for the
|
|
* simple case of truncating from one position in the tail to another.
|
|
*
|
|
*/
|
|
void xdr_truncate_encode(struct xdr_stream *xdr, size_t len)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
struct kvec *head = buf->head;
|
|
struct kvec *tail = buf->tail;
|
|
int fraglen;
|
|
int new;
|
|
|
|
if (len > buf->len) {
|
|
WARN_ON_ONCE(1);
|
|
return;
|
|
}
|
|
xdr_commit_encode(xdr);
|
|
|
|
fraglen = min_t(int, buf->len - len, tail->iov_len);
|
|
tail->iov_len -= fraglen;
|
|
buf->len -= fraglen;
|
|
if (tail->iov_len) {
|
|
xdr->p = tail->iov_base + tail->iov_len;
|
|
WARN_ON_ONCE(!xdr->end);
|
|
WARN_ON_ONCE(!xdr->iov);
|
|
return;
|
|
}
|
|
WARN_ON_ONCE(fraglen);
|
|
fraglen = min_t(int, buf->len - len, buf->page_len);
|
|
buf->page_len -= fraglen;
|
|
buf->len -= fraglen;
|
|
|
|
new = buf->page_base + buf->page_len;
|
|
|
|
xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT);
|
|
|
|
if (buf->page_len) {
|
|
xdr->p = page_address(*xdr->page_ptr);
|
|
xdr->end = (void *)xdr->p + PAGE_SIZE;
|
|
xdr->p = (void *)xdr->p + (new % PAGE_SIZE);
|
|
WARN_ON_ONCE(xdr->iov);
|
|
return;
|
|
}
|
|
if (fraglen)
|
|
xdr->end = head->iov_base + head->iov_len;
|
|
/* (otherwise assume xdr->end is already set) */
|
|
xdr->page_ptr--;
|
|
head->iov_len = len;
|
|
buf->len = len;
|
|
xdr->p = head->iov_base + head->iov_len;
|
|
xdr->iov = buf->head;
|
|
}
|
|
EXPORT_SYMBOL(xdr_truncate_encode);
|
|
|
|
/**
|
|
* xdr_restrict_buflen - decrease available buffer space
|
|
* @xdr: pointer to xdr_stream
|
|
* @newbuflen: new maximum number of bytes available
|
|
*
|
|
* Adjust our idea of how much space is available in the buffer.
|
|
* If we've already used too much space in the buffer, returns -1.
|
|
* If the available space is already smaller than newbuflen, returns 0
|
|
* and does nothing. Otherwise, adjusts xdr->buf->buflen to newbuflen
|
|
* and ensures xdr->end is set at most offset newbuflen from the start
|
|
* of the buffer.
|
|
*/
|
|
int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
int left_in_this_buf = (void *)xdr->end - (void *)xdr->p;
|
|
int end_offset = buf->len + left_in_this_buf;
|
|
|
|
if (newbuflen < 0 || newbuflen < buf->len)
|
|
return -1;
|
|
if (newbuflen > buf->buflen)
|
|
return 0;
|
|
if (newbuflen < end_offset)
|
|
xdr->end = (void *)xdr->end + newbuflen - end_offset;
|
|
buf->buflen = newbuflen;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(xdr_restrict_buflen);
|
|
|
|
/**
|
|
* xdr_write_pages - Insert a list of pages into an XDR buffer for sending
|
|
* @xdr: pointer to xdr_stream
|
|
* @pages: list of pages
|
|
* @base: offset of first byte
|
|
* @len: length of data in bytes
|
|
*
|
|
*/
|
|
void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base,
|
|
unsigned int len)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
struct kvec *iov = buf->tail;
|
|
buf->pages = pages;
|
|
buf->page_base = base;
|
|
buf->page_len = len;
|
|
|
|
iov->iov_base = (char *)xdr->p;
|
|
iov->iov_len = 0;
|
|
xdr->iov = iov;
|
|
|
|
if (len & 3) {
|
|
unsigned int pad = 4 - (len & 3);
|
|
|
|
BUG_ON(xdr->p >= xdr->end);
|
|
iov->iov_base = (char *)xdr->p + (len & 3);
|
|
iov->iov_len += pad;
|
|
len += pad;
|
|
*xdr->p++ = 0;
|
|
}
|
|
buf->buflen += len;
|
|
buf->len += len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_write_pages);
|
|
|
|
static unsigned int xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,
|
|
unsigned int base, unsigned int len)
|
|
{
|
|
if (len > iov->iov_len)
|
|
len = iov->iov_len;
|
|
if (unlikely(base > len))
|
|
base = len;
|
|
xdr->p = (__be32*)(iov->iov_base + base);
|
|
xdr->end = (__be32*)(iov->iov_base + len);
|
|
xdr->iov = iov;
|
|
xdr->page_ptr = NULL;
|
|
return len - base;
|
|
}
|
|
|
|
static unsigned int xdr_set_tail_base(struct xdr_stream *xdr,
|
|
unsigned int base, unsigned int len)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
|
|
xdr_stream_set_pos(xdr, base + buf->page_len + buf->head->iov_len);
|
|
return xdr_set_iov(xdr, buf->tail, base, len);
|
|
}
|
|
|
|
static unsigned int xdr_set_page_base(struct xdr_stream *xdr,
|
|
unsigned int base, unsigned int len)
|
|
{
|
|
unsigned int pgnr;
|
|
unsigned int maxlen;
|
|
unsigned int pgoff;
|
|
unsigned int pgend;
|
|
void *kaddr;
|
|
|
|
maxlen = xdr->buf->page_len;
|
|
if (base >= maxlen)
|
|
return 0;
|
|
else
|
|
maxlen -= base;
|
|
if (len > maxlen)
|
|
len = maxlen;
|
|
|
|
xdr_stream_page_set_pos(xdr, base);
|
|
base += xdr->buf->page_base;
|
|
|
|
pgnr = base >> PAGE_SHIFT;
|
|
xdr->page_ptr = &xdr->buf->pages[pgnr];
|
|
kaddr = page_address(*xdr->page_ptr);
|
|
|
|
pgoff = base & ~PAGE_MASK;
|
|
xdr->p = (__be32*)(kaddr + pgoff);
|
|
|
|
pgend = pgoff + len;
|
|
if (pgend > PAGE_SIZE)
|
|
pgend = PAGE_SIZE;
|
|
xdr->end = (__be32*)(kaddr + pgend);
|
|
xdr->iov = NULL;
|
|
return len;
|
|
}
|
|
|
|
static void xdr_set_page(struct xdr_stream *xdr, unsigned int base,
|
|
unsigned int len)
|
|
{
|
|
if (xdr_set_page_base(xdr, base, len) == 0) {
|
|
base -= xdr->buf->page_len;
|
|
xdr_set_tail_base(xdr, base, len);
|
|
}
|
|
}
|
|
|
|
static void xdr_set_next_page(struct xdr_stream *xdr)
|
|
{
|
|
unsigned int newbase;
|
|
|
|
newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
|
|
newbase -= xdr->buf->page_base;
|
|
if (newbase < xdr->buf->page_len)
|
|
xdr_set_page_base(xdr, newbase, xdr_stream_remaining(xdr));
|
|
else
|
|
xdr_set_tail_base(xdr, 0, xdr_stream_remaining(xdr));
|
|
}
|
|
|
|
static bool xdr_set_next_buffer(struct xdr_stream *xdr)
|
|
{
|
|
if (xdr->page_ptr != NULL)
|
|
xdr_set_next_page(xdr);
|
|
else if (xdr->iov == xdr->buf->head)
|
|
xdr_set_page(xdr, 0, xdr_stream_remaining(xdr));
|
|
return xdr->p != xdr->end;
|
|
}
|
|
|
|
/**
|
|
* xdr_init_decode - Initialize an xdr_stream for decoding data.
|
|
* @xdr: pointer to xdr_stream struct
|
|
* @buf: pointer to XDR buffer from which to decode data
|
|
* @p: current pointer inside XDR buffer
|
|
* @rqst: pointer to controlling rpc_rqst, for debugging
|
|
*/
|
|
void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
|
|
struct rpc_rqst *rqst)
|
|
{
|
|
xdr->buf = buf;
|
|
xdr_reset_scratch_buffer(xdr);
|
|
xdr->nwords = XDR_QUADLEN(buf->len);
|
|
if (xdr_set_iov(xdr, buf->head, 0, buf->len) == 0 &&
|
|
xdr_set_page_base(xdr, 0, buf->len) == 0)
|
|
xdr_set_iov(xdr, buf->tail, 0, buf->len);
|
|
if (p != NULL && p > xdr->p && xdr->end >= p) {
|
|
xdr->nwords -= p - xdr->p;
|
|
xdr->p = p;
|
|
}
|
|
xdr->rqst = rqst;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_init_decode);
|
|
|
|
/**
|
|
* xdr_init_decode_pages - Initialize an xdr_stream for decoding into pages
|
|
* @xdr: pointer to xdr_stream struct
|
|
* @buf: pointer to XDR buffer from which to decode data
|
|
* @pages: list of pages to decode into
|
|
* @len: length in bytes of buffer in pages
|
|
*/
|
|
void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
|
|
struct page **pages, unsigned int len)
|
|
{
|
|
memset(buf, 0, sizeof(*buf));
|
|
buf->pages = pages;
|
|
buf->page_len = len;
|
|
buf->buflen = len;
|
|
buf->len = len;
|
|
xdr_init_decode(xdr, buf, NULL, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_init_decode_pages);
|
|
|
|
static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
|
|
{
|
|
unsigned int nwords = XDR_QUADLEN(nbytes);
|
|
__be32 *p = xdr->p;
|
|
__be32 *q = p + nwords;
|
|
|
|
if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p))
|
|
return NULL;
|
|
xdr->p = q;
|
|
xdr->nwords -= nwords;
|
|
return p;
|
|
}
|
|
|
|
static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
|
|
{
|
|
__be32 *p;
|
|
char *cpdest = xdr->scratch.iov_base;
|
|
size_t cplen = (char *)xdr->end - (char *)xdr->p;
|
|
|
|
if (nbytes > xdr->scratch.iov_len)
|
|
goto out_overflow;
|
|
p = __xdr_inline_decode(xdr, cplen);
|
|
if (p == NULL)
|
|
return NULL;
|
|
memcpy(cpdest, p, cplen);
|
|
if (!xdr_set_next_buffer(xdr))
|
|
goto out_overflow;
|
|
cpdest += cplen;
|
|
nbytes -= cplen;
|
|
p = __xdr_inline_decode(xdr, nbytes);
|
|
if (p == NULL)
|
|
return NULL;
|
|
memcpy(cpdest, p, nbytes);
|
|
return xdr->scratch.iov_base;
|
|
out_overflow:
|
|
trace_rpc_xdr_overflow(xdr, nbytes);
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* xdr_inline_decode - Retrieve XDR data to decode
|
|
* @xdr: pointer to xdr_stream struct
|
|
* @nbytes: number of bytes of data to decode
|
|
*
|
|
* Check if the input buffer is long enough to enable us to decode
|
|
* 'nbytes' more bytes of data starting at the current position.
|
|
* If so return the current pointer, then update the current
|
|
* pointer position.
|
|
*/
|
|
__be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
|
|
{
|
|
__be32 *p;
|
|
|
|
if (unlikely(nbytes == 0))
|
|
return xdr->p;
|
|
if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
|
|
goto out_overflow;
|
|
p = __xdr_inline_decode(xdr, nbytes);
|
|
if (p != NULL)
|
|
return p;
|
|
return xdr_copy_to_scratch(xdr, nbytes);
|
|
out_overflow:
|
|
trace_rpc_xdr_overflow(xdr, nbytes);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_inline_decode);
|
|
|
|
static void xdr_realign_pages(struct xdr_stream *xdr)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
struct kvec *iov = buf->head;
|
|
unsigned int cur = xdr_stream_pos(xdr);
|
|
unsigned int copied;
|
|
|
|
/* Realign pages to current pointer position */
|
|
if (iov->iov_len > cur) {
|
|
copied = xdr_shrink_bufhead(buf, cur);
|
|
trace_rpc_xdr_alignment(xdr, cur, copied);
|
|
xdr_set_page(xdr, 0, buf->page_len);
|
|
}
|
|
}
|
|
|
|
static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
unsigned int nwords = XDR_QUADLEN(len);
|
|
unsigned int copied;
|
|
|
|
if (xdr->nwords == 0)
|
|
return 0;
|
|
|
|
xdr_realign_pages(xdr);
|
|
if (nwords > xdr->nwords) {
|
|
nwords = xdr->nwords;
|
|
len = nwords << 2;
|
|
}
|
|
if (buf->page_len <= len)
|
|
len = buf->page_len;
|
|
else if (nwords < xdr->nwords) {
|
|
/* Truncate page data and move it into the tail */
|
|
copied = xdr_shrink_pagelen(buf, len);
|
|
trace_rpc_xdr_alignment(xdr, len, copied);
|
|
}
|
|
return len;
|
|
}
|
|
|
|
/**
|
|
* xdr_read_pages - align page-based XDR data to current pointer position
|
|
* @xdr: pointer to xdr_stream struct
|
|
* @len: number of bytes of page data
|
|
*
|
|
* Moves data beyond the current pointer position from the XDR head[] buffer
|
|
* into the page list. Any data that lies beyond current position + @len
|
|
* bytes is moved into the XDR tail[]. The xdr_stream current position is
|
|
* then advanced past that data to align to the next XDR object in the tail.
|
|
*
|
|
* Returns the number of XDR encoded bytes now contained in the pages
|
|
*/
|
|
unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
|
|
{
|
|
unsigned int nwords = XDR_QUADLEN(len);
|
|
unsigned int base, end, pglen;
|
|
|
|
pglen = xdr_align_pages(xdr, nwords << 2);
|
|
if (pglen == 0)
|
|
return 0;
|
|
|
|
base = (nwords << 2) - pglen;
|
|
end = xdr_stream_remaining(xdr) - pglen;
|
|
|
|
xdr_set_tail_base(xdr, base, end);
|
|
return len <= pglen ? len : pglen;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_read_pages);
|
|
|
|
unsigned int xdr_align_data(struct xdr_stream *xdr, unsigned int offset,
|
|
unsigned int length)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
unsigned int from, bytes, len;
|
|
unsigned int shift;
|
|
|
|
xdr_realign_pages(xdr);
|
|
from = xdr_page_pos(xdr);
|
|
|
|
if (from >= buf->page_len + buf->tail->iov_len)
|
|
return 0;
|
|
if (from + buf->head->iov_len >= buf->len)
|
|
return 0;
|
|
|
|
len = buf->len - buf->head->iov_len;
|
|
|
|
/* We only shift data left! */
|
|
if (WARN_ONCE(from < offset, "SUNRPC: misaligned data src=%u dst=%u\n",
|
|
from, offset))
|
|
return 0;
|
|
if (WARN_ONCE(offset > buf->page_len,
|
|
"SUNRPC: buffer overflow. offset=%u, page_len=%u\n",
|
|
offset, buf->page_len))
|
|
return 0;
|
|
|
|
/* Move page data to the left */
|
|
shift = from - offset;
|
|
xdr_buf_pages_shift_left(buf, from, len, shift);
|
|
|
|
bytes = xdr_stream_remaining(xdr);
|
|
if (length > bytes)
|
|
length = bytes;
|
|
bytes -= length;
|
|
|
|
xdr->buf->len -= shift;
|
|
xdr_set_page(xdr, offset + length, bytes);
|
|
return length;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_align_data);
|
|
|
|
unsigned int xdr_expand_hole(struct xdr_stream *xdr, unsigned int offset,
|
|
unsigned int length)
|
|
{
|
|
struct xdr_buf *buf = xdr->buf;
|
|
unsigned int from, to, shift;
|
|
|
|
xdr_realign_pages(xdr);
|
|
from = xdr_page_pos(xdr);
|
|
to = xdr_align_size(offset + length);
|
|
|
|
/* Could the hole be behind us? */
|
|
if (to > from) {
|
|
unsigned int buflen = buf->len - buf->head->iov_len;
|
|
shift = to - from;
|
|
xdr_buf_try_expand(buf, shift);
|
|
xdr_buf_pages_shift_right(buf, from, buflen, shift);
|
|
xdr_set_page(xdr, to, xdr_stream_remaining(xdr));
|
|
} else if (to != from)
|
|
xdr_align_data(xdr, to, 0);
|
|
xdr_buf_pages_zero(buf, offset, length);
|
|
|
|
return length;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_expand_hole);
|
|
|
|
/**
|
|
* xdr_enter_page - decode data from the XDR page
|
|
* @xdr: pointer to xdr_stream struct
|
|
* @len: number of bytes of page data
|
|
*
|
|
* Moves data beyond the current pointer position from the XDR head[] buffer
|
|
* into the page list. Any data that lies beyond current position + "len"
|
|
* bytes is moved into the XDR tail[]. The current pointer is then
|
|
* repositioned at the beginning of the first XDR page.
|
|
*/
|
|
void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
|
|
{
|
|
len = xdr_align_pages(xdr, len);
|
|
/*
|
|
* Position current pointer at beginning of tail, and
|
|
* set remaining message length.
|
|
*/
|
|
if (len != 0)
|
|
xdr_set_page_base(xdr, 0, len);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_enter_page);
|
|
|
|
static const struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
|
|
|
|
void xdr_buf_from_iov(const struct kvec *iov, struct xdr_buf *buf)
|
|
{
|
|
buf->head[0] = *iov;
|
|
buf->tail[0] = empty_iov;
|
|
buf->page_len = 0;
|
|
buf->buflen = buf->len = iov->iov_len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_buf_from_iov);
|
|
|
|
/**
|
|
* xdr_buf_subsegment - set subbuf to a portion of buf
|
|
* @buf: an xdr buffer
|
|
* @subbuf: the result buffer
|
|
* @base: beginning of range in bytes
|
|
* @len: length of range in bytes
|
|
*
|
|
* sets @subbuf to an xdr buffer representing the portion of @buf of
|
|
* length @len starting at offset @base.
|
|
*
|
|
* @buf and @subbuf may be pointers to the same struct xdr_buf.
|
|
*
|
|
* Returns -1 if base of length are out of bounds.
|
|
*/
|
|
int xdr_buf_subsegment(const struct xdr_buf *buf, struct xdr_buf *subbuf,
|
|
unsigned int base, unsigned int len)
|
|
{
|
|
subbuf->buflen = subbuf->len = len;
|
|
if (base < buf->head[0].iov_len) {
|
|
subbuf->head[0].iov_base = buf->head[0].iov_base + base;
|
|
subbuf->head[0].iov_len = min_t(unsigned int, len,
|
|
buf->head[0].iov_len - base);
|
|
len -= subbuf->head[0].iov_len;
|
|
base = 0;
|
|
} else {
|
|
base -= buf->head[0].iov_len;
|
|
subbuf->head[0].iov_base = buf->head[0].iov_base;
|
|
subbuf->head[0].iov_len = 0;
|
|
}
|
|
|
|
if (base < buf->page_len) {
|
|
subbuf->page_len = min(buf->page_len - base, len);
|
|
base += buf->page_base;
|
|
subbuf->page_base = base & ~PAGE_MASK;
|
|
subbuf->pages = &buf->pages[base >> PAGE_SHIFT];
|
|
len -= subbuf->page_len;
|
|
base = 0;
|
|
} else {
|
|
base -= buf->page_len;
|
|
subbuf->pages = buf->pages;
|
|
subbuf->page_base = 0;
|
|
subbuf->page_len = 0;
|
|
}
|
|
|
|
if (base < buf->tail[0].iov_len) {
|
|
subbuf->tail[0].iov_base = buf->tail[0].iov_base + base;
|
|
subbuf->tail[0].iov_len = min_t(unsigned int, len,
|
|
buf->tail[0].iov_len - base);
|
|
len -= subbuf->tail[0].iov_len;
|
|
base = 0;
|
|
} else {
|
|
base -= buf->tail[0].iov_len;
|
|
subbuf->tail[0].iov_base = buf->tail[0].iov_base;
|
|
subbuf->tail[0].iov_len = 0;
|
|
}
|
|
|
|
if (base || len)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_buf_subsegment);
|
|
|
|
/**
|
|
* xdr_stream_subsegment - set @subbuf to a portion of @xdr
|
|
* @xdr: an xdr_stream set up for decoding
|
|
* @subbuf: the result buffer
|
|
* @nbytes: length of @xdr to extract, in bytes
|
|
*
|
|
* Sets up @subbuf to represent a portion of @xdr. The portion
|
|
* starts at the current offset in @xdr, and extends for a length
|
|
* of @nbytes. If this is successful, @xdr is advanced to the next
|
|
* XDR data item following that portion.
|
|
*
|
|
* Return values:
|
|
* %true: @subbuf has been initialized, and @xdr has been advanced.
|
|
* %false: a bounds error has occurred
|
|
*/
|
|
bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
|
|
unsigned int nbytes)
|
|
{
|
|
unsigned int start = xdr_stream_pos(xdr);
|
|
unsigned int remaining, len;
|
|
|
|
/* Extract @subbuf and bounds-check the fn arguments */
|
|
if (xdr_buf_subsegment(xdr->buf, subbuf, start, nbytes))
|
|
return false;
|
|
|
|
/* Advance @xdr by @nbytes */
|
|
for (remaining = nbytes; remaining;) {
|
|
if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
|
|
return false;
|
|
|
|
len = (char *)xdr->end - (char *)xdr->p;
|
|
if (remaining <= len) {
|
|
xdr->p = (__be32 *)((char *)xdr->p +
|
|
(remaining + xdr_pad_size(nbytes)));
|
|
break;
|
|
}
|
|
|
|
xdr->p = (__be32 *)((char *)xdr->p + len);
|
|
xdr->end = xdr->p;
|
|
remaining -= len;
|
|
}
|
|
|
|
xdr_stream_set_pos(xdr, start + nbytes);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_stream_subsegment);
|
|
|
|
/**
|
|
* xdr_buf_trim - lop at most "len" bytes off the end of "buf"
|
|
* @buf: buf to be trimmed
|
|
* @len: number of bytes to reduce "buf" by
|
|
*
|
|
* Trim an xdr_buf by the given number of bytes by fixing up the lengths. Note
|
|
* that it's possible that we'll trim less than that amount if the xdr_buf is
|
|
* too small, or if (for instance) it's all in the head and the parser has
|
|
* already read too far into it.
|
|
*/
|
|
void xdr_buf_trim(struct xdr_buf *buf, unsigned int len)
|
|
{
|
|
size_t cur;
|
|
unsigned int trim = len;
|
|
|
|
if (buf->tail[0].iov_len) {
|
|
cur = min_t(size_t, buf->tail[0].iov_len, trim);
|
|
buf->tail[0].iov_len -= cur;
|
|
trim -= cur;
|
|
if (!trim)
|
|
goto fix_len;
|
|
}
|
|
|
|
if (buf->page_len) {
|
|
cur = min_t(unsigned int, buf->page_len, trim);
|
|
buf->page_len -= cur;
|
|
trim -= cur;
|
|
if (!trim)
|
|
goto fix_len;
|
|
}
|
|
|
|
if (buf->head[0].iov_len) {
|
|
cur = min_t(size_t, buf->head[0].iov_len, trim);
|
|
buf->head[0].iov_len -= cur;
|
|
trim -= cur;
|
|
}
|
|
fix_len:
|
|
buf->len -= (len - trim);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_buf_trim);
|
|
|
|
static void __read_bytes_from_xdr_buf(const struct xdr_buf *subbuf,
|
|
void *obj, unsigned int len)
|
|
{
|
|
unsigned int this_len;
|
|
|
|
this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
|
|
memcpy(obj, subbuf->head[0].iov_base, this_len);
|
|
len -= this_len;
|
|
obj += this_len;
|
|
this_len = min_t(unsigned int, len, subbuf->page_len);
|
|
_copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len);
|
|
len -= this_len;
|
|
obj += this_len;
|
|
this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
|
|
memcpy(obj, subbuf->tail[0].iov_base, this_len);
|
|
}
|
|
|
|
/* obj is assumed to point to allocated memory of size at least len: */
|
|
int read_bytes_from_xdr_buf(const struct xdr_buf *buf, unsigned int base,
|
|
void *obj, unsigned int len)
|
|
{
|
|
struct xdr_buf subbuf;
|
|
int status;
|
|
|
|
status = xdr_buf_subsegment(buf, &subbuf, base, len);
|
|
if (status != 0)
|
|
return status;
|
|
__read_bytes_from_xdr_buf(&subbuf, obj, len);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf);
|
|
|
|
static void __write_bytes_to_xdr_buf(const struct xdr_buf *subbuf,
|
|
void *obj, unsigned int len)
|
|
{
|
|
unsigned int this_len;
|
|
|
|
this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
|
|
memcpy(subbuf->head[0].iov_base, obj, this_len);
|
|
len -= this_len;
|
|
obj += this_len;
|
|
this_len = min_t(unsigned int, len, subbuf->page_len);
|
|
_copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len);
|
|
len -= this_len;
|
|
obj += this_len;
|
|
this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
|
|
memcpy(subbuf->tail[0].iov_base, obj, this_len);
|
|
}
|
|
|
|
/* obj is assumed to point to allocated memory of size at least len: */
|
|
int write_bytes_to_xdr_buf(const struct xdr_buf *buf, unsigned int base,
|
|
void *obj, unsigned int len)
|
|
{
|
|
struct xdr_buf subbuf;
|
|
int status;
|
|
|
|
status = xdr_buf_subsegment(buf, &subbuf, base, len);
|
|
if (status != 0)
|
|
return status;
|
|
__write_bytes_to_xdr_buf(&subbuf, obj, len);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf);
|
|
|
|
int xdr_decode_word(const struct xdr_buf *buf, unsigned int base, u32 *obj)
|
|
{
|
|
__be32 raw;
|
|
int status;
|
|
|
|
status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
|
|
if (status)
|
|
return status;
|
|
*obj = be32_to_cpu(raw);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_decode_word);
|
|
|
|
int xdr_encode_word(const struct xdr_buf *buf, unsigned int base, u32 obj)
|
|
{
|
|
__be32 raw = cpu_to_be32(obj);
|
|
|
|
return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_encode_word);
|
|
|
|
/* Returns 0 on success, or else a negative error code. */
|
|
static int xdr_xcode_array2(const struct xdr_buf *buf, unsigned int base,
|
|
struct xdr_array2_desc *desc, int encode)
|
|
{
|
|
char *elem = NULL, *c;
|
|
unsigned int copied = 0, todo, avail_here;
|
|
struct page **ppages = NULL;
|
|
int err;
|
|
|
|
if (encode) {
|
|
if (xdr_encode_word(buf, base, desc->array_len) != 0)
|
|
return -EINVAL;
|
|
} else {
|
|
if (xdr_decode_word(buf, base, &desc->array_len) != 0 ||
|
|
desc->array_len > desc->array_maxlen ||
|
|
(unsigned long) base + 4 + desc->array_len *
|
|
desc->elem_size > buf->len)
|
|
return -EINVAL;
|
|
}
|
|
base += 4;
|
|
|
|
if (!desc->xcode)
|
|
return 0;
|
|
|
|
todo = desc->array_len * desc->elem_size;
|
|
|
|
/* process head */
|
|
if (todo && base < buf->head->iov_len) {
|
|
c = buf->head->iov_base + base;
|
|
avail_here = min_t(unsigned int, todo,
|
|
buf->head->iov_len - base);
|
|
todo -= avail_here;
|
|
|
|
while (avail_here >= desc->elem_size) {
|
|
err = desc->xcode(desc, c);
|
|
if (err)
|
|
goto out;
|
|
c += desc->elem_size;
|
|
avail_here -= desc->elem_size;
|
|
}
|
|
if (avail_here) {
|
|
if (!elem) {
|
|
elem = kmalloc(desc->elem_size, GFP_KERNEL);
|
|
err = -ENOMEM;
|
|
if (!elem)
|
|
goto out;
|
|
}
|
|
if (encode) {
|
|
err = desc->xcode(desc, elem);
|
|
if (err)
|
|
goto out;
|
|
memcpy(c, elem, avail_here);
|
|
} else
|
|
memcpy(elem, c, avail_here);
|
|
copied = avail_here;
|
|
}
|
|
base = buf->head->iov_len; /* align to start of pages */
|
|
}
|
|
|
|
/* process pages array */
|
|
base -= buf->head->iov_len;
|
|
if (todo && base < buf->page_len) {
|
|
unsigned int avail_page;
|
|
|
|
avail_here = min(todo, buf->page_len - base);
|
|
todo -= avail_here;
|
|
|
|
base += buf->page_base;
|
|
ppages = buf->pages + (base >> PAGE_SHIFT);
|
|
base &= ~PAGE_MASK;
|
|
avail_page = min_t(unsigned int, PAGE_SIZE - base,
|
|
avail_here);
|
|
c = kmap(*ppages) + base;
|
|
|
|
while (avail_here) {
|
|
avail_here -= avail_page;
|
|
if (copied || avail_page < desc->elem_size) {
|
|
unsigned int l = min(avail_page,
|
|
desc->elem_size - copied);
|
|
if (!elem) {
|
|
elem = kmalloc(desc->elem_size,
|
|
GFP_KERNEL);
|
|
err = -ENOMEM;
|
|
if (!elem)
|
|
goto out;
|
|
}
|
|
if (encode) {
|
|
if (!copied) {
|
|
err = desc->xcode(desc, elem);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
memcpy(c, elem + copied, l);
|
|
copied += l;
|
|
if (copied == desc->elem_size)
|
|
copied = 0;
|
|
} else {
|
|
memcpy(elem + copied, c, l);
|
|
copied += l;
|
|
if (copied == desc->elem_size) {
|
|
err = desc->xcode(desc, elem);
|
|
if (err)
|
|
goto out;
|
|
copied = 0;
|
|
}
|
|
}
|
|
avail_page -= l;
|
|
c += l;
|
|
}
|
|
while (avail_page >= desc->elem_size) {
|
|
err = desc->xcode(desc, c);
|
|
if (err)
|
|
goto out;
|
|
c += desc->elem_size;
|
|
avail_page -= desc->elem_size;
|
|
}
|
|
if (avail_page) {
|
|
unsigned int l = min(avail_page,
|
|
desc->elem_size - copied);
|
|
if (!elem) {
|
|
elem = kmalloc(desc->elem_size,
|
|
GFP_KERNEL);
|
|
err = -ENOMEM;
|
|
if (!elem)
|
|
goto out;
|
|
}
|
|
if (encode) {
|
|
if (!copied) {
|
|
err = desc->xcode(desc, elem);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
memcpy(c, elem + copied, l);
|
|
copied += l;
|
|
if (copied == desc->elem_size)
|
|
copied = 0;
|
|
} else {
|
|
memcpy(elem + copied, c, l);
|
|
copied += l;
|
|
if (copied == desc->elem_size) {
|
|
err = desc->xcode(desc, elem);
|
|
if (err)
|
|
goto out;
|
|
copied = 0;
|
|
}
|
|
}
|
|
}
|
|
if (avail_here) {
|
|
kunmap(*ppages);
|
|
ppages++;
|
|
c = kmap(*ppages);
|
|
}
|
|
|
|
avail_page = min(avail_here,
|
|
(unsigned int) PAGE_SIZE);
|
|
}
|
|
base = buf->page_len; /* align to start of tail */
|
|
}
|
|
|
|
/* process tail */
|
|
base -= buf->page_len;
|
|
if (todo) {
|
|
c = buf->tail->iov_base + base;
|
|
if (copied) {
|
|
unsigned int l = desc->elem_size - copied;
|
|
|
|
if (encode)
|
|
memcpy(c, elem + copied, l);
|
|
else {
|
|
memcpy(elem + copied, c, l);
|
|
err = desc->xcode(desc, elem);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
todo -= l;
|
|
c += l;
|
|
}
|
|
while (todo) {
|
|
err = desc->xcode(desc, c);
|
|
if (err)
|
|
goto out;
|
|
c += desc->elem_size;
|
|
todo -= desc->elem_size;
|
|
}
|
|
}
|
|
err = 0;
|
|
|
|
out:
|
|
kfree(elem);
|
|
if (ppages)
|
|
kunmap(*ppages);
|
|
return err;
|
|
}
|
|
|
|
int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
|
|
struct xdr_array2_desc *desc)
|
|
{
|
|
if (base >= buf->len)
|
|
return -EINVAL;
|
|
|
|
return xdr_xcode_array2(buf, base, desc, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_decode_array2);
|
|
|
|
int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
|
|
struct xdr_array2_desc *desc)
|
|
{
|
|
if ((unsigned long) base + 4 + desc->array_len * desc->elem_size >
|
|
buf->head->iov_len + buf->page_len + buf->tail->iov_len)
|
|
return -EINVAL;
|
|
|
|
return xdr_xcode_array2(buf, base, desc, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_encode_array2);
|
|
|
|
int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset,
|
|
unsigned int len,
|
|
int (*actor)(struct scatterlist *, void *), void *data)
|
|
{
|
|
int i, ret = 0;
|
|
unsigned int page_len, thislen, page_offset;
|
|
struct scatterlist sg[1];
|
|
|
|
sg_init_table(sg, 1);
|
|
|
|
if (offset >= buf->head[0].iov_len) {
|
|
offset -= buf->head[0].iov_len;
|
|
} else {
|
|
thislen = buf->head[0].iov_len - offset;
|
|
if (thislen > len)
|
|
thislen = len;
|
|
sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
|
|
ret = actor(sg, data);
|
|
if (ret)
|
|
goto out;
|
|
offset = 0;
|
|
len -= thislen;
|
|
}
|
|
if (len == 0)
|
|
goto out;
|
|
|
|
if (offset >= buf->page_len) {
|
|
offset -= buf->page_len;
|
|
} else {
|
|
page_len = buf->page_len - offset;
|
|
if (page_len > len)
|
|
page_len = len;
|
|
len -= page_len;
|
|
page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1);
|
|
i = (offset + buf->page_base) >> PAGE_SHIFT;
|
|
thislen = PAGE_SIZE - page_offset;
|
|
do {
|
|
if (thislen > page_len)
|
|
thislen = page_len;
|
|
sg_set_page(sg, buf->pages[i], thislen, page_offset);
|
|
ret = actor(sg, data);
|
|
if (ret)
|
|
goto out;
|
|
page_len -= thislen;
|
|
i++;
|
|
page_offset = 0;
|
|
thislen = PAGE_SIZE;
|
|
} while (page_len != 0);
|
|
offset = 0;
|
|
}
|
|
if (len == 0)
|
|
goto out;
|
|
if (offset < buf->tail[0].iov_len) {
|
|
thislen = buf->tail[0].iov_len - offset;
|
|
if (thislen > len)
|
|
thislen = len;
|
|
sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
|
|
ret = actor(sg, data);
|
|
len -= thislen;
|
|
}
|
|
if (len != 0)
|
|
ret = -EINVAL;
|
|
out:
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_process_buf);
|
|
|
|
/**
|
|
* xdr_stream_decode_opaque - Decode variable length opaque
|
|
* @xdr: pointer to xdr_stream
|
|
* @ptr: location to store opaque data
|
|
* @size: size of storage buffer @ptr
|
|
*
|
|
* Return values:
|
|
* On success, returns size of object stored in *@ptr
|
|
* %-EBADMSG on XDR buffer overflow
|
|
* %-EMSGSIZE on overflow of storage buffer @ptr
|
|
*/
|
|
ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size)
|
|
{
|
|
ssize_t ret;
|
|
void *p;
|
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
|
|
if (ret <= 0)
|
|
return ret;
|
|
memcpy(ptr, p, ret);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque);
|
|
|
|
/**
|
|
* xdr_stream_decode_opaque_dup - Decode and duplicate variable length opaque
|
|
* @xdr: pointer to xdr_stream
|
|
* @ptr: location to store pointer to opaque data
|
|
* @maxlen: maximum acceptable object size
|
|
* @gfp_flags: GFP mask to use
|
|
*
|
|
* 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
|
|
* %-ENOMEM on memory allocation failure
|
|
*/
|
|
ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
|
|
size_t maxlen, gfp_t gfp_flags)
|
|
{
|
|
ssize_t ret;
|
|
void *p;
|
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
|
|
if (ret > 0) {
|
|
*ptr = kmemdup(p, ret, gfp_flags);
|
|
if (*ptr != NULL)
|
|
return ret;
|
|
ret = -ENOMEM;
|
|
}
|
|
*ptr = NULL;
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup);
|
|
|
|
/**
|
|
* xdr_stream_decode_string - Decode variable length string
|
|
* @xdr: pointer to xdr_stream
|
|
* @str: location to store string
|
|
* @size: size of storage buffer @str
|
|
*
|
|
* Return values:
|
|
* On success, returns length of NUL-terminated string stored in *@str
|
|
* %-EBADMSG on XDR buffer overflow
|
|
* %-EMSGSIZE on overflow of storage buffer @str
|
|
*/
|
|
ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size)
|
|
{
|
|
ssize_t ret;
|
|
void *p;
|
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, size);
|
|
if (ret > 0) {
|
|
memcpy(str, p, ret);
|
|
str[ret] = '\0';
|
|
return strlen(str);
|
|
}
|
|
*str = '\0';
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_string);
|
|
|
|
/**
|
|
* xdr_stream_decode_string_dup - Decode and duplicate variable length string
|
|
* @xdr: pointer to xdr_stream
|
|
* @str: location to store pointer to string
|
|
* @maxlen: maximum acceptable string length
|
|
* @gfp_flags: GFP mask to use
|
|
*
|
|
* Return values:
|
|
* On success, returns length of NUL-terminated string stored in *@ptr
|
|
* %-EBADMSG on XDR buffer overflow
|
|
* %-EMSGSIZE if the size of the string would exceed @maxlen
|
|
* %-ENOMEM on memory allocation failure
|
|
*/
|
|
ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
|
|
size_t maxlen, gfp_t gfp_flags)
|
|
{
|
|
void *p;
|
|
ssize_t ret;
|
|
|
|
ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen);
|
|
if (ret > 0) {
|
|
char *s = kmemdup_nul(p, ret, gfp_flags);
|
|
if (s != NULL) {
|
|
*str = s;
|
|
return strlen(s);
|
|
}
|
|
ret = -ENOMEM;
|
|
}
|
|
*str = NULL;
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup);
|