[Inotify-tools] How to monitor a UNIX domain socket?

[Alexander K. <Ale...@Kr...>]

Maybe this is unrelated to inotify-tools' purpose, but I hope to find
support or a good idea anyway. I work on an embedded platform (mipsel)
and have used inotify-tools, especially inotifywait, for a long time to
write simple watchdogs based on file access, change, deletion etc.

Now there is a tricky case: I need to monitor that fact that and also
*what* is written into a UNIX domain socket, i.e. I want to monitor IPC
because there is no API to catch certain events and trigger actions.

I tried inotify-tools in vain for monitoring UNIX domain sockets, but I
am asking anyway: Is there a way to do that? If not with inotify-tools,
maybe there is something similar for my purpose. I found out that strace
can trace the calls and contents which send and receive messages in UNIX
domain sockets, but would be quite slow and expensive to have strace
running on a vital process in my firmware all the time. What I learned
from this, though, is that there is a programmatic way to gather the
information I am looking for and trigger an event (in strace: write a
log line).

I already explained my problem on stackoverflow.com [1] more than 2
weeks ago, but received no answer. So it seems to be a tricky or at
least not everyday thing. Any ideas?

[1] http://stackoverflow.com/questions/8394613/watchdog-monitoring-unix-domain-socket-triggering-events-upon-specific-content