SUNRPC: Handle zero length fragments correctly

A zero length fragment is really a bug, but let's ensure we don't
go nuts when one turns up.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2019-02-15 18:14:27 -05:00
parent ae05355151
commit e92053a52e

View File

@ -405,8 +405,8 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
size_t want, seek_init = seek, offset = 0;
ssize_t ret;
if (seek < buf->head[0].iov_len) {
want = min_t(size_t, count, buf->head[0].iov_len);
want = min_t(size_t, count, buf->head[0].iov_len);
if (seek < want) {
ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
if (ret <= 0)
goto sock_err;
@ -417,8 +417,8 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
goto out;
seek = 0;
} else {
seek -= buf->head[0].iov_len;
offset += buf->head[0].iov_len;
seek -= want;
offset += want;
}
want = xs_alloc_sparse_pages(buf,
@ -443,8 +443,8 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
offset += want;
}
if (seek < buf->tail[0].iov_len) {
want = min_t(size_t, count - offset, buf->tail[0].iov_len);
want = min_t(size_t, count - offset, buf->tail[0].iov_len);
if (seek < want) {
ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
if (ret <= 0)
goto sock_err;
@ -454,7 +454,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
if (ret != want)
goto out;
} else
offset += buf->tail[0].iov_len;
offset = seek_init;
ret = -EMSGSIZE;
out:
*read = offset - seek_init;
@ -482,6 +482,14 @@ xs_read_stream_request_done(struct sock_xprt *transport)
return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
}
static void
xs_read_stream_check_eor(struct sock_xprt *transport,
struct msghdr *msg)
{
if (xs_read_stream_request_done(transport))
msg->msg_flags |= MSG_EOR;
}
static ssize_t
xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
int flags, struct rpc_rqst *req)
@ -493,17 +501,24 @@ xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
xs_read_header(transport, buf);
want = transport->recv.len - transport->recv.offset;
ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
transport->recv.copied + want, transport->recv.copied,
&read);
transport->recv.offset += read;
transport->recv.copied += read;
if (want != 0) {
ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
transport->recv.copied + want,
transport->recv.copied,
&read);
transport->recv.offset += read;
transport->recv.copied += read;
} else
read = 0;
if (transport->recv.offset == transport->recv.len) {
if (xs_read_stream_request_done(transport))
msg->msg_flags |= MSG_EOR;
xs_read_stream_check_eor(transport, msg);
return read;
}
if (want == 0)
return 0;
switch (ret) {
default:
break;