metrics: gate listener with allowed_ips ACL

Parse the `allowed_ips` option in [metrics] as a comma-separated list
of IPv4 CIDR entries. Both the bracketed form

    allowed_ips = ["1.2.3.4/32", "5.6.7.0/24"]

and a bare comma-separated form are accepted; surrounding whitespace,
matched quotes, and the optional [ ] are stripped. A bare address
without a prefix is treated as /32.

When the list is empty (option missing or empty value), all peers are
allowed and behavior is unchanged. Otherwise serv_read() rejects any
peer that doesn't match a configured CIDR by closing the freshly
accepted socket before allocating client state, so scanners get
nothing more than a TCP reset.

Signed-off-by: Denys Fedoryshchenko <denys.f@collabora.com>

0 files changed, 0 insertions, 0 deletions