Switched to a recursive mutex so that procedures which need to perform
lookups can do so while also maintaining the lock across their entire
body in order to guarantee atomicity for each environment operation.
This removes the data race caused by multiple threads using the
unprotected global `random_string_seed`, so long as no two threads share
the same random generator; this is the default case.
Additionally, `os2.random_string` now takes into account the full buffer
slice given to it.
`strings.to_cstring` previously would not check if the buffer could
handle the extra null byte and could lead to segmentation violations
when using the resulting string in an API expecting the terminator.
Adds a directory walker, a method of exposing and retrieving errors from
the existing read directory iterator, allows reusing of the existing
read directory iterator, and adds a file clone procedure
This fixes some vulnerabilities in the resolver that make spoofing DNS
queries somewhat trivial due to the code failing to randomize xid, as
well as match the reply xid with the query, and the origin of the packet:
- xid of the query was fixed at zero
- xid from the reply was never checked
- source address of the reply was never checked
This means anyone can flood the host with a fake reply with xid 0,
guessing the source port is trivial as it's less than 16bits (2^16 -
1024), which would cause odin to resolve a hostname to whatever an
attacker wanted.
While here also plug in two memory leaks.
Since this is CVE material, I've contacted @kelimion before hand which
instructed to put it in a PR.
There are also more bugs as the code conflates answer section,
authority section and aditional section into one, while in reality
only the anwer section should be taken into consideration.
This allows `*` to be used in C fashion, without specifying an argument
index to use. Like C, this results in the argument *preceding* the value
for the format specifier itself.
