On 14/10/13 21:26, Daniel P. Berrange wrote:
On Mon, Oct 14, 2013 at 03:22:27PM +0800, Osier Yang wrote:
<...> /* Size of message length field. Not counted in VIR_NET_MESSAGE_MAX * and VIR_NET_MESSAGE_INITIAL. */ const VIR_NET_MESSAGE_LEN_MAX = 4; </...>
However, msg->bufferLength includes the length word. The wrong checking was introduced by commit e914dcfd.
* src/rpc/virnetmessage.c: - Correct the checking in virNetMessageEncodePayloadRaw - Use a new variable to track the new payload length in virNetMessageEncodePayloadRaw --- src/rpc/virnetmessage.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/src/rpc/virnetmessage.c b/src/rpc/virnetmessage.c index 8f4e4bc..4c60424 100644 --- a/src/rpc/virnetmessage.c +++ b/src/rpc/virnetmessage.c @@ -346,15 +346,17 @@ int virNetMessageEncodePayload(virNetMessagePtr msg,
/* Try to encode the payload. If the buffer is too small increase it. */ while (!(*filter)(&xdr, data)) { - if ((msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX) * 4 > VIR_NET_MESSAGE_MAX) { + unsigned int newlen = (msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX) * 4 + + VIR_NET_MESSAGE_LEN_MAX; + + if (newlen > VIR_NET_MESSAGE_MAX + VIR_NET_MESSAGE_LEN_MAX) { You've not actually changed the logic here at all - you've just added VIR_NET_MESSAGE_LEN_MAX to both sides of the '>'. So this change is a no-op. Please drop it.
Yes, the logic is not changed, but I wanted to calculate the new buffer length once instead of twice, and it's more readable for the code. So I'd like keep it.
virReportError(VIR_ERR_RPC, "%s", _("Unable to encode message payload")); goto error; }
xdr_destroy(&xdr);
- msg->bufferLength = (msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX) * 4 + - VIR_NET_MESSAGE_LEN_MAX; + msg->bufferLength = newlen;
Again, nothing changed. Drop this.
if (VIR_REALLOC_N(msg->buffer, msg->bufferLength) < 0) goto error; @@ -426,10 +428,15 @@ int virNetMessageEncodePayloadRaw(virNetMessagePtr msg,
/* If the message buffer is too small for the payload increase it accordingly. */ if ((msg->bufferLength - msg->bufferOffset) < len) { - if ((msg->bufferOffset + len) > VIR_NET_MESSAGE_MAX) { + if ((msg->bufferOffset + len) > + VIR_NET_MESSAGE_MAX + VIR_NET_MESSAGE_LEN_MAX) {
Bracket both sides of the '>' for clarity, not just the left-hand-side.
So except this, Can I get an ACK?