only use the old fallback, or /dev/urandom
/dev/random blocks on some older unix machines,
or in embedded environments that may never
have enough entropy, causing the code to hang.
urandom is most certainly expected to exist on
pretty much anything since the mid 90s.
i could probably re-add the arc4random setup
for BSDs. i'll think about it. gotta do that
portably too.
Signed-off-by: Leah Rowe <leah@libreboot.org>
if someone calls rhex fast enough, the timestamp
may not change. this mitigates that by adding
a counter value to the mix
Signed-off-by: Leah Rowe <leah@libreboot.org>
skip it if there is a valid checksum, to mitigate
erroneous errno state upon exit from run_cmd(),
because we can assume by this point that we
are in fact ready to write at this point.
the check at the end still exists, which will catch
any error set by write, and any error set before
that. this fixes a weird warning on cmd_dump.
Signed-off-by: Leah Rowe <leah@libreboot.org>
reset it in callers instead.
this means that the main function is more generalised.
we know by the time we exit that there is no error.
Signed-off-by: Leah Rowe <leah@libreboot.org>
in the new file i/o functions, my own setting
of errno should be done with set_err. this
avoids clobbering what the real libc set.
Signed-off-by: Leah Rowe <leah@libreboot.org>
i set it to ecanceled before. now i set it more
appropriately, for each type of error.
where a real syscall was called, or my file i/o
functions are used, err() is called with errno
itself as input, to avoid clobbering real errno.
Signed-off-by: Leah Rowe <leah@libreboot.org>
in practise it's ok, but some compilers might complain.
all this change costs is a bit of branching inside a
loop, but compilers will sort that out.
Signed-off-by: Leah Rowe <leah@libreboot.org>
preventative fix, since the values are currently
quite tiny. this new check is the same, but goes
the other way to eliminate overflow.
Signed-off-by: Leah Rowe <leah@libreboot.org>
the old one assumes that ssize_t is signed size_t,
which let's face it, is always true in practise,
but not actually guaranteed!
so now i'm using one that's even more pedantic.
Signed-off-by: Leah Rowe <leah@libreboot.org>
just use errno itself as input to err
if unset, it's set to ECANCELED anyway
i really should rewrite the error handling
to not use errno at some point. it's a bit
unreliable, on some unix systems.
Signed-off-by: Leah Rowe <leah@libreboot.org>
if it resets it on success, that is!
theoretically possible. we must preserve errno.
normally i'm a bit more casual about it, but this
function is replicating libc, so i must be strict
Signed-off-by: Leah Rowe <leah@libreboot.org>
Leah Rowe