Merge pull request #1187 from hannesm/v6

IPv6 stack support for the mirage utility

CHANGES.md

@@ -1,3 +1,99 @@
+### v3.10.0 (2020-12-02)
+
+IPv6 and dual (IPv4 and IPv6) stack support #1187
+
+Since a long time, IPv6 code was around in our TCP/IP stack (thanks to @nojb
+who developed it in 2014). Some months ago, @hannesm and @MagnusS got excited
+to use it. After we managed to fix some bugs and add some test cases, and
+writing more code to setup IPv6-only and dual stacks, we are eager to share
+this support for MirageOS in a released version. We expect there to be bugs
+lingering around, but duplicate address detection (neighbour solicitation and
+advertisements) has been implemented, and (unless
+"--accept-router-advertisement=false") router advertisements are decoded and
+used to configure the IPv6 part of the stack. Configuring a static IPv6 address
+is also possible (with "--ipv6=2001::42/64").
+
+While at it, we unified the boot arguments between the different targets:
+namely, on Unix (when using the socket stack), you can now pass
+"--ipv4=127.0.0.1/24" to the same effect as the direct stack: only listen
+on 127.0.0.1 (the subnet mask is ignored for the Unix socket stack).
+
+A dual stack unikernel has "--ipv4-only=BOOL" and "--ipv6-only=BOOL" parameters,
+so a unikernel binary could support both Internet Protocol versions, while the
+operator can decide which protocol version to use.
+
+Please also note that the default IPv4 network configuration no longer uses
+10.0.0.1 as default gateway (since there was no way to unset the default
+gateway #1147).
+
+For unikernel developers, there are some API changes in the Mirage module
+- New "v4v6" types for IP protocols and stacks
+- The ipv6_config record was adjusted in the same fashion as the ipv4_config
+  type: it is now a record of a network (V6.Prefix.t) and gateway (V6.t option)
+
+Some parts of the Mirage_key module were unified as well:
+- Arp.ip_address is available (for a dual Ipaddr.t)
+- Arg.ipv6_address replaces Arg.ipv6 (for an Ipaddr.V6.t)
+- Arg.ipv6 replaces Arg.ipv6_prefix (for a Ipaddr.V6.Prefix.t)
+- V6.network and V6.gateway are available, mirroring the V4 submodule
+
+If you're ready to experiment with the dual stack, here's a diff for our basic
+network example (from mirage-skeleton/device-usage/network) replacing IPv4
+with a dual stack:
+
+```
+diff --git a/device-usage/network/config.ml b/device-usage/network/config.ml
+index c425edb..eabc9d6 100644
+--- a/device-usage/network/config.ml
++++ b/device-usage/network/config.ml
+@@ -4,9 +4,9 @@ let port =
+   let doc = Key.Arg.info ~doc:"The TCP port on which to listen for incoming connections." ["port"] in
+   Key.(create "port" Arg.(opt int 8080 doc))
+ 
+-let main = foreign ~keys:[Key.abstract port] "Unikernel.Main" (stackv4 @-> job)
++let main = foreign ~keys:[Key.abstract port] "Unikernel.Main" (stackv4v6 @-> job)
+ 
+-let stack = generic_stackv4 default_network
++let stack = generic_stackv4v6 default_network
+ 
+ let () =
+   register "network" [
+diff --git a/device-usage/network/unikernel.ml b/device-usage/network/unikernel.ml
+index 5d29111..1bf1228 100644
+--- a/device-usage/network/unikernel.ml
++++ b/device-usage/network/unikernel.ml
+@@ -1,19 +1,19 @@
+ open Lwt.Infix
+ 
+-module Main (S: Mirage_stack.V4) = struct
++module Main (S: Mirage_stack.V4V6) = struct
+ 
+   let start s =
+     let port = Key_gen.port () in
+-    S.listen_tcpv4 s ~port (fun flow ->
+-        let dst, dst_port = S.TCPV4.dst flow in
++    S.listen_tcp s ~port (fun flow ->
++        let dst, dst_port = S.TCP.dst flow in
+         Logs.info (fun f -> f "new tcp connection from IP %s on port %d"
+-                  (Ipaddr.V4.to_string dst) dst_port);
+-        S.TCPV4.read flow >>= function
++                  (Ipaddr.to_string dst) dst_port);
++        S.TCP.read flow >>= function
+         | Ok `Eof -> Logs.info (fun f -> f "Closing connection!"); Lwt.return_unit
+-        | Error e -> Logs.warn (fun f -> f "Error reading data from established connection: %a" S.TCPV4.pp_error e); Lwt.return_unit
++        | Error e -> Logs.warn (fun f -> f "Error reading data from established connection: %a" S.TCP.pp_error e); Lwt.return_unit
+         | Ok (`Data b) ->
+           Logs.debug (fun f -> f "read: %d bytes:\n%s" (Cstruct.len b) (Cstruct.to_string b));
+-          S.TCPV4.close flow
++          S.TCP.close flow
+       );
+ 
+     S.listen s
+```
+
+Other bug fixes include #1188 (in #1201) and adapt to charrua 1.3.0 and
+arp 2.3.0 changes (#1199).
+
 ### v3.9.0 (2020-10-24)
 
 The Xen backend is a minimal legacy-free re-write: Solo5 (since 0.6.6) provides

lib/mirage.ml

@@ -97,50 +97,75 @@ let arp = Mirage_impl_arpv4.arp
 
 type v4 = Mirage_impl_ip.v4
 type v6 = Mirage_impl_ip.v6
+type v4v6 = Mirage_impl_ip.v4v6
 type 'a ip = 'a Mirage_impl_ip.ip
 type ipv4 = Mirage_impl_ip.ipv4
 type ipv6 = Mirage_impl_ip.ipv6
+type ipv4v6 = Mirage_impl_ip.ipv4v6
 let ipv4 = Mirage_impl_ip.ipv4
 let ipv6 = Mirage_impl_ip.ipv6
+let ipv4v6 = Mirage_impl_ip.ipv4v6
 let ipv4_qubes = Mirage_impl_ip.ipv4_qubes
 let create_ipv4 = Mirage_impl_ip.create_ipv4
 let create_ipv6 = Mirage_impl_ip.create_ipv6
+let create_ipv4v6 = Mirage_impl_ip.create_ipv4v6
 type ipv4_config = Mirage_impl_ip.ipv4_config = {
   network : Ipaddr.V4.Prefix.t;
   gateway : Ipaddr.V4.t option;
 }
 type ipv6_config = Mirage_impl_ip.ipv6_config = {
-  addresses : Ipaddr.V6.t list;
-  netmasks  : Ipaddr.V6.Prefix.t list;
-  gateways  : Ipaddr.V6.t list;
+  network  : Ipaddr.V6.Prefix.t;
+  gateway  : Ipaddr.V6.t option;
 }
 
 type 'a udp = 'a Mirage_impl_udp.udp
 let udp = Mirage_impl_udp.udp
 type udpv4 = Mirage_impl_udp.udpv4
 type udpv6 = Mirage_impl_udp.udpv6
+type udpv4v6 = Mirage_impl_udp.udpv4v6
 let udpv4 = Mirage_impl_udp.udpv4
 let udpv6 = Mirage_impl_udp.udpv6
+let udpv4v6 = Mirage_impl_udp.udpv4v6
 let direct_udp = Mirage_impl_udp.direct_udp
 let socket_udpv4 = Mirage_impl_udp.socket_udpv4
+let socket_udpv6 = Mirage_impl_udp.socket_udpv6
+let socket_udpv4v6 = Mirage_impl_udp.socket_udpv4v6
 
 type 'a tcp = 'a Mirage_impl_tcp.tcp
 let tcp = Mirage_impl_tcp.tcp
 type tcpv4 = Mirage_impl_tcp.tcpv4
 type tcpv6 = Mirage_impl_tcp.tcpv6
+type tcpv4v6 = Mirage_impl_tcp.tcpv4v6
 let tcpv4 = Mirage_impl_tcp.tcpv4
 let tcpv6 = Mirage_impl_tcp.tcpv6
+let tcpv4v6 = Mirage_impl_tcp.tcpv4v6
 let direct_tcp = Mirage_impl_tcp.direct_tcp
 let socket_tcpv4 = Mirage_impl_tcp.socket_tcpv4
-
-type stackv4 = Mirage_impl_stackv4.stackv4
-let stackv4 = Mirage_impl_stackv4.stackv4
-let generic_stackv4 = Mirage_impl_stackv4.generic_stackv4
-let static_ipv4_stack = Mirage_impl_stackv4.static_ipv4_stack
-let dhcp_ipv4_stack = Mirage_impl_stackv4.dhcp_ipv4_stack
-let qubes_ipv4_stack = Mirage_impl_stackv4.qubes_ipv4_stack
-let direct_stackv4 = Mirage_impl_stackv4.direct_stackv4
-let socket_stackv4 = Mirage_impl_stackv4.socket_stackv4
+let socket_tcpv6 = Mirage_impl_tcp.socket_tcpv6
+let socket_tcpv4v6 = Mirage_impl_tcp.socket_tcpv4v6
+
+type stackv4 = Mirage_impl_stack.stackv4
+let stackv4 = Mirage_impl_stack.stackv4
+let generic_stackv4 = Mirage_impl_stack.generic_stackv4
+let static_ipv4_stack = Mirage_impl_stack.static_ipv4_stack
+let dhcp_ipv4_stack = Mirage_impl_stack.dhcp_ipv4_stack
+let qubes_ipv4_stack = Mirage_impl_stack.qubes_ipv4_stack
+let direct_stackv4 = Mirage_impl_stack.direct_stackv4
+let socket_stackv4 = Mirage_impl_stack.socket_stackv4
+
+type stackv6 = Mirage_impl_stack.stackv6
+let stackv6 = Mirage_impl_stack.stackv6
+let generic_stackv6 = Mirage_impl_stack.generic_stackv6
+let static_ipv6_stack = Mirage_impl_stack.static_ipv6_stack
+let direct_stackv6 = Mirage_impl_stack.direct_stackv6
+let socket_stackv6 = Mirage_impl_stack.socket_stackv6
+
+type stackv4v6 = Mirage_impl_stack.stackv4v6
+let stackv4v6 = Mirage_impl_stack.stackv4v6
+let generic_stackv4v6 = Mirage_impl_stack.generic_stackv4v6
+let static_ipv4v6_stack = Mirage_impl_stack.static_ipv4v6_stack
+let direct_stackv4v6 = Mirage_impl_stack.direct_stackv4v6
+let socket_stackv4v6 = Mirage_impl_stack.socket_stackv4v6
 
 type conduit = Mirage_impl_conduit.conduit
 let conduit = Mirage_impl_conduit.conduit
@@ -158,7 +183,7 @@ let syslog_tcp = Mirage_impl_syslog.syslog_tcp
 let syslog_udp = Mirage_impl_syslog.syslog_udp
 type syslog_config = Mirage_impl_syslog.syslog_config =
   { hostname : string;
-    server   : Ipaddr.V4.t option;
+    server   : Ipaddr.t option;
     port     : int option;
     truncate : int option;
   }
@@ -219,7 +244,7 @@ module Project = struct
       ]
       method! packages =
         (* XXX: use %%VERSION_NUM%% here instead of hardcoding a version? *)
-        let min = "3.9.0" and max = "3.10.0" in
+        let min = "3.10.0" and max = "3.11.0" in
         let common = [
           package ~build:true ~min:"4.08.0" "ocaml";
           package "lwt";