tree aed82b0aa13d4a7826f2713eda1b2a777c21cf43
parent de806dfdb6dd3b9dec5d1d23c9029fb300799cf8
author Erik Kline <ek@google.com> 1415993080 +0900
committer Erik Kline <ek@google.com> 1416562460 +0900

Fun with buffer overrruns.

In get_option(): don't read past the end of the option buffer.

Also add a small unittest to verify sane behaviour for the above.
The dhcpcd code is not easily refactored into a library, nor is it
entirely possible to include some header files directly since some
structures use C++ reserved keywords ("new") for variable names.

In print_option(): use of snprintf() returns the length that
/would/ have been written.  Add checks that the output buffer
is not overrun when printing.

Bug: 18356137
Bug: 18356135
Change-Id: I0f907b8a952208749226ba034a416d773e068f8a