[ntpsec commit] Add some banned functions.

[Eric S. Raymond]

Module:    ntpsec
Branch:    master
Commit:    c73676401fa4b70d6ebed1f4dfb26bd273a06321
Changeset: http://git.ntpsec.org/ntpsec/commit/?id=c73676401fa4b70d6ebed1f4dfb26bd273a06321

Author:    Eric S. Raymond <esr at thyrsus.com>
Date:      Mon Oct  5 13:59:31 2015 -0400

Add some banned functions.

---

 devel-docs/hacking.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/devel-docs/hacking.txt b/devel-docs/hacking.txt
index cd3dd40..a797f89 100644
--- a/devel-docs/hacking.txt
+++ b/devel-docs/hacking.txt
@@ -47,10 +47,12 @@ cause buffer overruns and (all too often) exploitable security holes:
 
 * strcpy, strncpy, strcat:  Use strlcpy and strlcat instead.
 * sprintf, vsprintf: use snprintf and vsnprintf instead.
+* In scanf and friends, the %s format without length limit is banned.
 * strtok: use strtok_r() or unroll this into the obvious loop.
 * gets: Use fgets instead. 
 * gmtime(), localtime(), asctime(), ctime(): use the reentrant *_r variants.
 * tmpnam() - use mkstemp() or tmpfile() instead.
+* dirname() - the Linux version is re-entrant but this property is not portable.
 
 In general, avoid functions that are non-reentrant.  When in doubt, see
 http://www.unix.org/whitepapers/reentrant.html[Thread-safety and POSIX.1]