bind() call on IPv4 sockets:
Currently, if one tries to bind a socket using INADDR_LOOPBACK inside a
jail, it will fail because prison_ip() does not take this possibility
into account. On the other hand, when one tries to connect(), for
example, to localhost, prison_remote_ip() will silently convert
INADDR_LOOPBACK to the jail's IP address. Therefore, it is desirable to
make bind() to do this implicit conversion as well.
Apart from this, the patch also replaces 0x7f000001 in
prison_remote_ip() to a more correct INADDR_LOOPBACK.
This is a 4.4-RELEASE "during the freeze, thanks" MFC candidate.
Submitted by: Anton Berezin <tobez@FreeBSD.org>
Discussed with at some point: phk
MFC after: 3 days
8c4571a0e7