On Thu, Jun 23, 2011 at 04:19:37PM -0600, Eric Blake wrote:
On 06/22/2011 09:33 AM, Daniel P. Berrange wrote:
This provides a new struct that contains a buffer for the RPC message header+payload, as well as a decoded copy of the message header. There is an API for applying a XDR encoding & decoding of the message headers and payloads. There are also APIs for maintaining a simple FIFO queue of message instances.
Expected usage scenarios are:
To send a message
msg = virNetMessageNew()
...fill in msg->header fields.. virNetMessageEncodeHeader(msg) ...loook at msg->header fields to determine payload filter virNetMessageEncodePayload(msg, xdrfilter, data) ...send msg->bufferLength worth of data from buffer
To receive a message
msg = virNetMessageNew() ...read VIR_NET_MESSAGE_LEN_MAX of data into buffer virNetMessageDecodeLength(msg) ...read msg->bufferLength-msg->bufferOffset of data into buffer virNetMessageDecodeHeader(msg) ...look at msg->header fields to determine payload filter virNetMessageDecodePayload(msg, xdrfilter, data) ...run payload processor
'make check' fails:
virnetmessagetest-virnetmessagetest.o: In function `testMessageHeaderEncode': /home/remote/eblake/libvirt/tests/virnetmessagetest.c:57: undefined reference to `virNetMessageEncodeHeader'
But that was easy enough to fix.
Sigh. I have rebased this patch series sooooo many times now, that I lost some pieces :-( Your suggested change is what I originally had.
+++ b/src/rpc/virnetmessage.h @@ -0,0 +1,82 @@ +/*
+ +#ifndef __VIR_NET_MESSAGE_H__ +# define __VIR_NET_MESSAGE_H__ + +# include <stdbool.h>
Is this include still necessary?
No, it should be able to go.
+int virtTestDifferenceBin(FILE *stream, + const char *expect, + const char *actual, + size_t length) +{ + size_t start = 0, end = length; + ssize_t i; + + if (!virTestGetDebug()) + return 0; + + if (virTestGetDebug() < 2) { + /* Skip to first character where they differ */ + for (i = 0 ; i < length ; i++) { + if (expect[i] != actual[i]) { + start = i; + break; + } + } + + /* Work backwards to last character where they differ */ + for (i = (length -1) ; i >= 0 ; i--) { + if (expect[i] != actual[i]) { + end = i; + break; + } + } + } + /* Round to nearest boundary of 4 */ + start -= (start % 4); + end += 4 - (end % 4);
This could make end go beyond length, if the difference was in the last byte or two on an unaligned length. And if expect or actual are also unaligned, then this means that reading beyond bounds could segfault (at any rate, valgrind will certainly call you on it).
Hmm, interesting edge case. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|