Commit bd8100e7 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Trond Myklebust

[PATCH] RPC: Encode and decode arbitrary XDR arrays

Signed-off-by: default avatarAndreas Gruenbacher <agruen@suse.de>
Acked-by: default avatarOlaf Kirch <okir@suse.de>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 7e06b53d
......@@ -146,7 +146,8 @@ 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 *, int, int);
extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, int);
extern int read_bytes_from_xdr_buf(struct xdr_buf *buf, int base, void *obj, int len);
extern int read_bytes_from_xdr_buf(struct xdr_buf *, int, void *, int);
extern int write_bytes_to_xdr_buf(struct xdr_buf *, int, void *, int);
/*
* Helper structure for copying from an sk_buff.
......@@ -168,6 +169,22 @@ struct sockaddr;
extern int xdr_sendpages(struct socket *, struct sockaddr *, int,
struct xdr_buf *, unsigned int, int);
extern int xdr_encode_word(struct xdr_buf *, int, u32);
extern int xdr_decode_word(struct xdr_buf *, 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;
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);
/*
* Provide some simple tools for XDR buffer overflow-checking etc.
*/
......
......@@ -129,6 +129,10 @@ EXPORT_SYMBOL(xdr_encode_netobj);
EXPORT_SYMBOL(xdr_encode_pages);
EXPORT_SYMBOL(xdr_inline_pages);
EXPORT_SYMBOL(xdr_shift_buf);
EXPORT_SYMBOL(xdr_encode_word);
EXPORT_SYMBOL(xdr_decode_word);
EXPORT_SYMBOL(xdr_encode_array2);
EXPORT_SYMBOL(xdr_decode_array2);
EXPORT_SYMBOL(xdr_buf_from_iov);
EXPORT_SYMBOL(xdr_buf_subsegment);
EXPORT_SYMBOL(xdr_buf_read_netobj);
......
......@@ -887,8 +887,34 @@ read_bytes_from_xdr_buf(struct xdr_buf *buf, int base, void *obj, int len)
return status;
}
static int
read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
/* obj is assumed to point to allocated memory of size at least len: */
int
write_bytes_to_xdr_buf(struct xdr_buf *buf, int base, void *obj, int len)
{
struct xdr_buf subbuf;
int this_len;
int status;
status = xdr_buf_subsegment(buf, &subbuf, base, len);
if (status)
goto out;
this_len = min(len, (int)subbuf.head[0].iov_len);
memcpy(subbuf.head[0].iov_base, obj, this_len);
len -= this_len;
obj += this_len;
this_len = min(len, (int)subbuf.page_len);
if (this_len)
_copy_to_pages(subbuf.pages, subbuf.page_base, obj, this_len);
len -= this_len;
obj += this_len;
this_len = min(len, (int)subbuf.tail[0].iov_len);
memcpy(subbuf.tail[0].iov_base, obj, this_len);
out:
return status;
}
int
xdr_decode_word(struct xdr_buf *buf, int base, u32 *obj)
{
u32 raw;
int status;
......@@ -900,6 +926,14 @@ read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
return 0;
}
int
xdr_encode_word(struct xdr_buf *buf, int base, u32 obj)
{
u32 raw = htonl(obj);
return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
}
/* If the netobj starting offset bytes from the start of xdr_buf is contained
* entirely in the head or the tail, set object to point to it; otherwise
* try to find space for it at the end of the tail, copy it there, and
......@@ -910,7 +944,7 @@ xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, int offset)
u32 tail_offset = buf->head[0].iov_len + buf->page_len;
u32 obj_end_offset;
if (read_u32_from_xdr_buf(buf, offset, &obj->len))
if (xdr_decode_word(buf, offset, &obj->len))
goto out;
obj_end_offset = offset + 4 + obj->len;
......@@ -943,3 +977,219 @@ xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, int offset)
out:
return -1;
}
/* Returns 0 on success, or else a negative error code. */
static int
xdr_xcode_array2(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 ||
(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_CACHE_SHIFT);
base &= ~PAGE_CACHE_MASK;
avail_page = min_t(unsigned int, PAGE_CACHE_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_CACHE_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:
if (elem)
kfree(elem);
if (ppages)
kunmap(*ppages);
return err;
}
int
xdr_decode_array2(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);
}
int
xdr_encode_array2(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);
}
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