Ban lists: where Guard and fail2ban ban addresses

A program bans an address (every port, or a protocol's ports) for a
time; the ban list says what it is kept from: the firewall, some hosts
behind it, or everything. Bans drop ahead of every rule, close the
address's connections, group IPv6 by /64, are kept in the database
across restarts and audited. Never banned: the inside, the firewall's
own addresses, the caller, the list's never. bans grant (bans:write:LIST),
hc banlist/bans/ban/unban, Traffic -> Bans, a fail2ban action in contrib/,
and failed logins and refused tokens logged for Guard and fail2ban.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/api/types.go

@@ -532,3 +532,35 @@ type MatrixException struct {
 	// Marks are the counters behind Hits ("r12", "b-ping", "f3").
 	Marks []string `json:"-"`
 }
+
+// BanInput asks a ban list to ban an address (POST
+// /banlists/{list}/bans).
+type BanInput struct {
+	Address string `json:"address"`
+	// Protocol (tcp, udp) and Ports limit the ban; with neither, every
+	// port. Ports are numbers or service names, in a list or a string
+	// ("22", "ssh", "http,https"); "all", "0:65535" or "1-65535" mean
+	// every port. Ports without a protocol take the service's protocols,
+	// or for a number tcp and udp.
+	Protocol string          `json:"protocol,omitempty"`
+	Ports    json.RawMessage `json:"ports,omitempty"`
+	// Time is the ban's length in seconds: 0 the list's default, -1 its
+	// longest (or for ever). Longer than the list allows is cut down.
+	Time   int    `json:"time,omitempty"`
+	Source string `json:"source,omitempty"`
+	Reason string `json:"reason,omitempty"`
+}
+
+// BanResult is the answer to a ban: the bans made or renewed (one per
+// protocol and port), Existing for each already in force.
+type BanResult struct {
+	Bans []BanMade `json:"bans"`
+	// Closed counts the banned address's connections closed.
+	Closed int `json:"closed"`
+}
+
+// BanMade is a ban made, or renewed (Existing).
+type BanMade struct {
+	model.Ban
+	Existing bool `json:"existing,omitempty"`
+}