Experimental Physics and
Industrial Control System

Ralph Lange <[email protected]> · Wed, 23 Aug 2006 16:05:59 +0200

Hm...

Ralf added some code to osiSockDiscoverBroadcastAddresses() that

memcpy-copies the odd-length ifreq into a word-aligned buffer, then uses

a pointer to this aligned copy to hand to the subsequent calls.

Effect: The RTEMS board boots, doesn't crash, and finds four interfaces

(lo: and eth0: both appear twice), two of which it recognizes as

AF_INET. External CA clients can connect, but get junk in the monitor

updates (time stamp and data are garbled).

So it seems that the returned ifreq length of 70 for the first interface

really is the reason for crashing on the second entry which is not aligned.

Would you see the additional buffer as an adequate way to handle this?

(Probably not...)

If not, where in the BSD network code would we have to add the padding?

Does the CA data garbling point to the same problem or to something else?

Ralph & Ralf

Jeff Hill wrote:

Agree with Eric's comment.

So you might have a closer look at ifreq_size ensuring that it's functioning
properly implemented for your ARM RTEMS. See examples below.

Jeff