shared: add independent IPv4 and IPv6 collection [CI]

backend/src/MoShiro.Backend.Application/Agents/AgentService.cs

@@ -1,3 +1,5 @@
+using System.Net;
+using System.Net.Sockets;
 using System.Text.RegularExpressions;
 using Fleet.Core;
 using Fleet.Server;
@@ -49,6 +51,16 @@ public sealed partial class AgentService
         return new AgentView(agent, _gateway.IsOnline(agent.Id), state?.Probes ?? [], state?.LastHeartbeat, state?.EndpointChanges ?? 0, state?.LastHeartbeatAtMs, state?.Host);
     }
 
+    private static bool ValidHost(string host, string ipVersion)
+    {
+        if (IPAddress.TryParse(host, out IPAddress? address))
+        {
+            return !address.IsIPv4MappedToIPv6 && address.AddressFamily == (ipVersion == IpVersions.V6 ? AddressFamily.InterNetworkV6 : AddressFamily.InterNetwork);
+        }
+
+        return host.Length <= 253 && Uri.CheckHostName(host) == UriHostNameType.Dns;
+    }
+
     public async ValueTask<Result<AgentView>> PatchAsync(NodeId id, AgentPatch patch, long? expectedRowVersion, CancellationToken ct)
     {
         var errors = new Dictionary<string, string>();
@@ -57,11 +69,16 @@ public sealed partial class AgentService
             errors["name"] = "must be 1-64 characters: letters (any language), digits, '.', '_' or '-'";
         }
 
-        if (patch.PublicHost is not null && !HostPattern().IsMatch(patch.PublicHost))
+        if (patch.PublicHost is not null && !ValidHost(patch.PublicHost, IpVersions.V4))
         {
             errors["public_host"] = "must be a host name or IP address";
         }
 
+        if (patch.Ipv6Host is not null && patch.Ipv6Host.Length > 0 && !ValidHost(patch.Ipv6Host, IpVersions.V6))
+        {
+            errors["ipv6_host"] = "must be an IPv6 address or host name; empty disables IPv6 collection";
+        }
+
         if (patch.Labels is not null && (patch.Labels.Count > 16 || patch.Labels.Any(l => l.Length is 0 or > 32)))
         {
             errors["labels"] = "at most 16 labels of 1-32 characters";
@@ -78,7 +95,7 @@ public sealed partial class AgentService
             return Result<AgentView>.Fail(error);
         }
 
-        if (patch.Name is not null || patch.PublicHost is not null)
+        if (patch.Name is not null || patch.PublicHost is not null || patch.Ipv6Host is not null)
         {
             await AfterAgentSetChangedAsync(ct);
         }
@@ -139,6 +156,7 @@ public sealed partial class AgentService
                 AgentId = agent.Id,
                 Name = agent.Name,
                 Host = agent.PublicHost,
+                Ipv6Host = agent.Ipv6Supported && agent.Ipv6Host.Length > 0 ? agent.Ipv6Host : null,
                 TcpPort = agent.ProbeTcpPort,
                 UdpPorts = [.. agent.ProbeUdpPorts],
                 Spki = Convert.ToBase64String(agent.TlsSpki),
@@ -170,7 +188,4 @@ public sealed partial class AgentService
 
     [GeneratedRegex(@"^[\p{L}\p{M}\p{N}._-]{1,64}$")]
     private static partial Regex NamePattern();
-
-    [GeneratedRegex(@"^[A-Za-z0-9.:\-\[\]]{1,253}$")]
-    private static partial Regex HostPattern();
 }