the system on which it is running. The hostname is reloaded when
'HUPped' and a log message generated to note a change (before anyone
points it out, this is not an added security feature).
PR: bin/24444
Reviewed by: freebsd-audit
Approved by: ru
MFC after: 2 weeks
- Lose any stray host bits that a user may have entered when providing
a network number and netmask to the `-a' option for IPv6. This is
corresponding to 1.79 that is for IPv4 only.
MFC after: 1 week
user unless they come directly from the kernel. Document this and
add a flag to syslogd which prevents this conversion.
Sort getopt args while I'm at it.
PR: 21788
Submitted by: Andre Albsmeier <andre.albsmeier@mchp.siemens.de>
Remove extra parens from my host selection commit.
Add white space after if, while, for and switch.
Get rid of braces around a single statement if.
There should be no functional changes in this commit.
Reviewed by: sheldonh
a similar way to the way it can select messages from a given program.
Lines beginning with "+hostname" or "#+hostname" select messaes
from that hostname and lines beginning with "-hostname" or "#-hostname"
match messages not from that hostname.
There are some significant style issues left in the original program
selection code and the man page. This should be cleared up in some
later commits.
Reviewed by: sheldonh
Based on an original patch by: Bernd Walter <ticso@cicely8.cicely.de>
Man page stylist: sheldonh
as they ought to be. The description of SA_RESTART was a little
unobvious to me in the man page, so i missed it. Thanks to Bruce for
spotting this.
Submitted by: bde
would cause syslogd to eventually kill innocent processes in the
system over time (note: not `could' but `would'). Many thanks to my
colleague Mirko for digging into the kernel structures and providing
me with the debugging framework to find out about the nature of this
bug (and to isolate that syslogd was the culprit) in a rather large
set of distributed machines at client sites where this happened
occasionally.
Whenever a child process was no longer responsive, or when syslogd
receives a SIGHUP so it closes all its logging file descriptors, for
any descriptor that refers to a pipe syslogd enters the data about the
old logging child process into a `dead queue', where it is being
removed from (and the status of the dead kitten being fetched) upon
receipt of a SIGCHLD. However, there's a high probability that the
SIGCHLD already arrives before the child's data are actually entered
into the dead queue inside the SIGHUP handler, so the SIGCHLD handler
has nothing to fetch and remove and simply continues. Whenever this
happens, the process'es data remain on the dead queue forever, and
since domark() tried to get rid of totally unresponsive children by
first sending a SIGTERM and later a SIGKILL, it was only a matter of
time until the system had recycled enough PIDs so an innocent process
got shot to death.
Fix the race by masking SIGHUP and SIGCHLD from both handlers mutually.
Add additional bandaids ``just in case'', i. e. don't enter a process
into the dead queue if we can't signal it (this should only happen in
case it is already dead by that time so we can fetch the status
immediately instead of deferring this to the SIGCHLD handler); for the
kill(2) inside domark(), check for an error status (/* Can't happen */
:) and remove it from the dead queue in this case (which if it would
have been there in the first place would have reduced the problem to a
statistically minimal likelihood so i certainly would never have
noticed the bug at all :).
Mirko also reviewed the fix in priciple (mutual blocking of both
signals inside the handlers), but not the actual code.
Reviewed by: Mirko Kaffka <mirko@interface-business.de>
Approved by: jkh
