RFC 3164 has a hostname between the priority and the message text, and we
were sending nothing there. A receiver still has to fill that field, so it
takes the first word of the text instead, so every line arrives attributed to
"STP:", or "REGGET:", or whatever the log happens to start with. The sender
is then impossible to select on: the name changes with the content, and
anything in front of us on the path replaces the source address with its
own.
Observed on a collector behind a UDP proxy: the same switch showed up as two
different hosts depending on which subsystem had logged last.
Send the configured hostname. Skipped when it is empty, so we never emit a
lone separator.
The header length lives in xdata rather than on the stack. syslog_callback()
is __banked, so a local there cannot be overlaid, and while the variable
itself is only two bytes it costs more than that: it takes a register, which
pushes log_start out of one and into internal RAM. Those two bytes are
enough to stop an image carrying LACP and STP from linking at all.
d00f
René van Dorst
bennydiamond
feelfree69