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[PATCH] RPC: fix accounting bug in the case of a truncated RPC message

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Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2005-06-22 17:16:24 +00:00
parent e053d1ab62
commit 7e06b53d79
3 changed files with 42 additions and 17 deletions
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2
include/linux/sunrpc/xdr.h
View file

@ -160,7 +160,7 @@ typedef struct {
typedef size_t (*skb_read_actor_t)(skb_reader_t *desc, void *to, size_t len);
extern int xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
skb_reader_t *, skb_read_actor_t);
struct socket;

22
net/sunrpc/xdr.c
View file

@ -176,21 +176,23 @@ xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
xdr->buflen += len;
}
int
ssize_t
xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base,
skb_reader_t *desc,
skb_read_actor_t copy_actor)
{
struct page **ppage = xdr->pages;
unsigned int len, pglen = xdr->page_len;
ssize_t copied = 0;
int ret;
len = xdr->head[0].iov_len;
if (base < len) {
len -= base;
ret = copy_actor(desc, (char *)xdr->head[0].iov_base + base, len);
copied += ret;
if (ret != len || !desc->count)
return 0;
goto out;
base = 0;
} else
base -= len;
@ -214,8 +216,11 @@ xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base,
* are small by default but can get huge. */
if (unlikely(*ppage == NULL)) {
*ppage = alloc_page(GFP_ATOMIC);
if (unlikely(*ppage == NULL))
return -ENOMEM;
if (unlikely(*ppage == NULL)) {
if (copied == 0)
copied = -ENOMEM;
goto out;
}
}
len = PAGE_CACHE_SIZE;
@ -233,16 +238,17 @@ xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base,
}
flush_dcache_page(*ppage);
kunmap_atomic(kaddr, KM_SKB_SUNRPC_DATA);
copied += ret;
if (ret != len || !desc->count)
return 0;
goto out;
ppage++;
} while ((pglen -= len) != 0);
copy_tail:
len = xdr->tail[0].iov_len;
if (base < len)
copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);
return 0;
copied += copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);
out:
return copied;
}

35
net/sunrpc/xprt.c
View file

@ -823,10 +823,15 @@ tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
{
if (len > desc->count)
len = desc->count;
if (skb_copy_bits(desc->skb, desc->offset, p, len))
if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
dprintk("RPC: failed to copy %zu bytes from skb. %zu bytes remain\n",
len, desc->count);
return 0;
}
desc->offset += len;
desc->count -= len;
dprintk("RPC: copied %zu bytes from skb. %zu bytes remain\n",
len, desc->count);
return len;
}
@ -865,6 +870,8 @@ tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
static void
tcp_check_recm(struct rpc_xprt *xprt)
{
dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
if (xprt->tcp_offset == xprt->tcp_reclen) {
xprt->tcp_flags |= XPRT_COPY_RECM;
xprt->tcp_offset = 0;
@ -909,7 +916,7 @@ tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
struct rpc_rqst *req;
struct xdr_buf *rcvbuf;
size_t len;
int r;
ssize_t r;
/* Find and lock the request corresponding to this xid */
spin_lock(&xprt->sock_lock);
@ -932,15 +939,17 @@ tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
my_desc.count = len;
r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
&my_desc, tcp_copy_data);
desc->count -= len;
desc->offset += len;
desc->count -= r;
desc->offset += r;
} else
r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
desc, tcp_copy_data);
xprt->tcp_copied += len;
xprt->tcp_offset += len;
if (r < 0) {
if (r > 0) {
xprt->tcp_copied += r;
xprt->tcp_offset += r;
}
if (r != len) {
/* Error when copying to the receive buffer,
* usually because we weren't able to allocate
* additional buffer pages. All we can do now
@ -951,9 +960,18 @@ tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
* be discarded.
*/
xprt->tcp_flags &= ~XPRT_COPY_DATA;
dprintk("RPC: XID %08x truncated request\n",
ntohl(xprt->tcp_xid));
dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
goto out;
}
dprintk("RPC: XID %08x read %u bytes\n",
ntohl(xprt->tcp_xid), r);
dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
if (xprt->tcp_copied == req->rq_private_buf.buflen)
xprt->tcp_flags &= ~XPRT_COPY_DATA;
else if (xprt->tcp_offset == xprt->tcp_reclen) {
@ -961,12 +979,12 @@ tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
xprt->tcp_flags &= ~XPRT_COPY_DATA;
}
out:
if (!(xprt->tcp_flags & XPRT_COPY_DATA)) {
dprintk("RPC: %4d received reply complete\n",
req->rq_task->tk_pid);
xprt_complete_rqst(xprt, req, xprt->tcp_copied);
}
out:
spin_unlock(&xprt->sock_lock);
tcp_check_recm(xprt);
}
@ -985,6 +1003,7 @@ tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
desc->count -= len;
desc->offset += len;
xprt->tcp_offset += len;
dprintk("RPC: discarded %u bytes\n", len);
tcp_check_recm(xprt);
}