shevek / libspf2

Implementation of the Sender Policy Framework for SMTP authorization
http://www.libspf2.net/
37 stars 32 forks source link

Expand Hostname Buffer #17

Open edwbuck opened 8 years ago

edwbuck commented 8 years ago

The buffer holding the results for gethostname now contains HOST_NAME_MAX + 1 characters so it may contain hostnames at HOST_NAME_MAX printable characters and a terminating null.

Prior to this change, the buffer could only accomodate hostnames of HOST_NAME_MAX - 1 characters.

If you had a hostname that was HOST_NAME_MAX (64 characters on Linux) with the old buffer, the call to gethostname(...) would succeed but truncate the hostname (the truncation behavior is not fully specified, according to the GETHOSTNAME(2) man page). On my platform, this led to a zero length hostname which caused subsequent failures.