part of an ifa_msghdr returned by sysctl(3), because that could
overwrite the ifam_len field of the following ifa_msgher. Instead,
copy the interface name out of the sockaddr_dl, and then nul-terminate.
Fixes the bug reported by Frank Kardel on current-users@. Thanks
Frank for reporting, and for testing the fix.
FORTIFY_SOURCE feature of libssp, thus checking the size of arguments to
various string and memory copy and set functions (as well as a few system
calls and other miscellany) where known at function entry. RedHat has
evidently built all "core system packages" with this option for some time.
This option should be used at the top of Makefiles (or Makefile.inc where
this is used for subdirectories) but after any setting of LIB.
This is only useful for userland code, and cannot be used in libc or in
any code which includes the libc internals, because it overrides certain
libc functions with macros. Some effort has been made to make USE_FORT=yes
work correctly for a full-system build by having the bsd.sys.mk logic
disable the feature where it should not be used (libc, libssp iteself,
the kernel) but no attempt has been made to build the entire system with
USE_FORT and doing so will doubtless expose numerous bugs and misfeatures.
Adjust the system build so that all programs and libraries that are setuid,
directly handle network data (including serial comm data), perform
authentication, or appear likely to have (or have a history of having)
data-driven bugs (e.g. file(1)) are built with USE_FORT=yes by default,
with the exception of libc, which cannot use USE_FORT and thus uses
only USE_SSP by default. Tested on i386 with no ill results; USE_FORT=no
per-directory or in a system build will disable if desired.
Wolfgang Solfrank has explained the problem with router discovery
in `routed` in a way I can understand.
Let's assume that the configured preference of the interface is 5.
This gets converted to 0x80000005 through the use of the UNSIGN_PREF
macro. Later on, this value gets put into the PREF macro, which
compares it against the interface metric(s) (let's assume those
values to be 0 for now). Of course the 0x80000005, cast to int,
is much less than 0, so the clamping rule is triggered, which
gives us a value of 1. This is then converted via SIGN_PREF into
0x80000001 and put into the message. Certainly, this isn't what
was intended.
