On Thu, Jun 17, 2004 at 12:03:59AM -0700, Shaun Jackman wrote:
> What follows is a patch to add serial infrared (SIR) decoding to
> Ethereal. It is used, for example, by two instances of Palm OS
> Emulator (Pose) to communicate using IrDA.
Should that be put in its own plugin dissector, or should it be added to
the "plugins/irda" directory? (It looks as if IrDA runs atop it, rather
than it running atop lower-level IrDA protocols.)
> Now a couple of notes. I believe the checksum is the same as that in
> PPP. This common code could be factored out.
If so, it should probably go into a "crc16.c" file, with a "crc16.h"
header, and called both by the PPP dissector and the SIR dissector;
"crc16.c" would be added to the DISSECTOR_SUPPORT_SRC macro in
"epan/Makefile.common".
> I've tested this as a plugin.
It would have to be added to the "plugin API" stuff to work on Windows
(at least until we make the plugins link against a libethereal.lib - or
whatever it is you do on Windows).
> Finally, it has one known bug. The protocol uses an escape sequence
> to escape control characters. These escape sequences should be dealt
> with before the buffer is passed to the next dissector (IrLAP). I
> wasn't sure of the best way to handle this.
The right way to handle that is probably to construct a buffer
containing an un-escaped packet, and then construct a new tvbuff out of
that buffer - see, for example, "packet-icq.c", in
"dissect_icqv5Client()" as an example of how to do that.
> +// prototypes
Not all compilers used to compile Ethereal accept C++-style comments.
To quote the "Portability" section of "doc/README.developer":
Don't use C++-style comments (comments beginning with "//" and running
to the end of the line); Ethereal's dissectors are written in C, and
thus run through C rather than C++ compilers, and not all C compilers
support C++-style comments (GCC does, but IBM's C compiler for AIX, for
example, doesn't do so by default).
> +#include <stdint.h>
% more /usr/include/stdint.h
/usr/include/stdint.h: No such file or directory
% uname -sr
FreeBSD 3.4-RELEASE
%more /usr/include/stdint.h
/usr/include/stdint.h: No such file or directory
%uname -sr
FreeBSD 4.6-RELEASE
<stdint.h> isn't in C89 (or, at least, not in my copy of the 1989 ANSI C
spec), and we don't require C99. Use GLib's types, such as "gint8",
"guint8", "gint16", "guint16", etc. instead.
