From 94c718948745cb7359002dbfd0e298203e574e02 Mon Sep 17 00:00:00 2001
Message-Id: <94c718948745cb7359002dbfd0e298203e574e02@dist-git>
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Fri, 26 May 2017 16:05:04 +0200
Subject: [PATCH] rpc: Double buffer size instead of quadrupling buffer size.
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When increasing the buffer size up to VIR_NET_MESSAGE_MAX, we
currently quadruple it each time.  This unfortunately means that we
cannot allow certain buffer sizes -- for example the current
VIR_NET_MESSAGE_MAX == 33554432 can never be "hit" since ‘newlen’
jumps from 16MB to 64MB.

Instead of quadrupling, double it each time.

Thanks: Daniel Berrange.
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
(cherry picked from commit b088f85d42a05a6c0c8418c02a67b48864ba95a3)

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1440683
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/rpc/virnetmessage.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/rpc/virnetmessage.c b/src/rpc/virnetmessage.c
index c3a2e595c..5908b074a 100644
--- a/src/rpc/virnetmessage.c
+++ b/src/rpc/virnetmessage.c
@@ -358,7 +358,8 @@ int virNetMessageEncodePayload(virNetMessagePtr msg,
 
     /* Try to encode the payload. If the buffer is too small increase it. */
     while (!(*filter)(&xdr, data, 0)) {
-        unsigned int newlen = (msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX) * 4;
+        unsigned int newlen = msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX;
+        newlen *= 2;
 
         if (newlen > VIR_NET_MESSAGE_MAX) {
             virReportError(VIR_ERR_RPC, "%s", _("Unable to encode message payload"));
-- 
2.13.0