tailcfg: add recorders field to SSHRule struct

This change introduces the Recorders field to the SSHRule struct. The
field is used to store and define addresses where the ssh recorder is
located.

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
(cherry picked from commit 3efd83555f)

tailcfg/tailcfg.go

@@ -1949,6 +1949,10 @@ type SSHRule struct {
 	// Action is the outcome to task.
 	// A nil or invalid action means to deny.
 	Action *SSHAction `json:"action"`
+
+	// Recorders defines the destinations of the SSH session recorders.
+	// The recording will be uploaded to http://addr:port/record.
+	Recorders []netip.AddrPort `json:"recorders"`
 }
 
 // SSHPrincipal is either a particular node or a user on any node.

tailcfg/tailcfg_clone.go

@@ -375,6 +375,7 @@ func (src *SSHRule) Clone() *SSHRule {
 		dst.Action = new(SSHAction)
 		*dst.Action = *src.Action
 	}
+	dst.Recorders = append(src.Recorders[:0:0], src.Recorders...)
 	return dst
 }
 
@@ -384,6 +385,7 @@ var _SSHRuleCloneNeedsRegeneration = SSHRule(struct {
 	Principals  []*SSHPrincipal
 	SSHUsers    map[string]string
 	Action      *SSHAction
+	Recorders   []netip.AddrPort
 }{})
 
 // Clone makes a deep copy of SSHPrincipal.

tailcfg/tailcfg_view.go

@@ -873,12 +873,15 @@ func (v SSHRuleView) Action() *SSHAction {
 	return &x
 }
 
+func (v SSHRuleView) Recorders() views.Slice[netip.AddrPort] { return views.SliceOf(v.ж.Recorders) }
+
 // A compilation failure here means this code must be regenerated, with the command at the top of this file.
 var _SSHRuleViewNeedsRegeneration = SSHRule(struct {
 	RuleExpires *time.Time
 	Principals  []*SSHPrincipal
 	SSHUsers    map[string]string
 	Action      *SSHAction
+	Recorders   []netip.AddrPort
 }{})
 
 // View returns a readonly view of SSHPrincipal.