lib: Replace shim IPCPs with points of attachment

Removes the UDP and Ethernet shim IPCPs. The unicast and broadcast
IPCPs can now directly attach to a "legacy" socket. We adopt Saltzer's
Point-of-Attachment terminology, also advocated in Day's "Patterns in
Network Architecture". The "poa" component manages these
PoA's with one management thread, one link monitoring thread and one
thread per attached point.

For Ethernet PoA's the irm connect and enroll can resolve the
destination IPCP or Layer name with a broadcast name query over the
attached PoAs (first reply wins). UDP PoA's require a destination IP
address or FQDN.

attach to a local endpoint (required both server and client side):

 irm ipcp poa attach name a udp 10.0.0.1
 irm ipcp poa attach name a udp 10.0.0.1:3435
 irm ipcp poa attach name a udp [::1]:3435
 irm ipcp poa attach name a eth dev eth0
 irm ipcp poa attach name a eth dev eth0 ethertype 0xA000

release a PoA (refused while it carries a flow):

 irm ipcp poa detach name a udp 10.0.0.1:3435
 irm ipcp poa detach name a eth eth0

list an IPCP's PoAs:

 irm ipcp poa list name a

connect to a peer, by name or at an address:

 irm ipcp connect name b dst a
 irm ipcp connect name b dst a eth
 irm ipcp connect name b dst a eth dev eth0
 irm ipcp connect name b dst a udp 10.0.0.1:3435
 irm ipcp connect name b dst a udp peer.example.com:3435

disconnect by peer name, no address:

 irm ipcp disconnect name b dst a
 irm ipcp disconnect name b dst a component mgmt

enroll has the same shape as connect:

 irm ipcp enroll name b layer lr autobind
 irm ipcp enroll name b layer lr autobind eth dev eth0
 irm ipcp enroll name b layer lr autobind udp 10.0.0.1:3435

the IRMd config file attaches PoAs and names peers the same way:

 udp = [ "10.0.0.1", "10.0.0.1:3436" ]
 eth = [ "eth0", {dev="eth1", ethertype=0xA007} ]

 enrol={dst="LAN", eth={dev="eth0"}}
 conn=[{dst="lan3", eth={}}, {dst="lan4", udp="10.0.0.1:3435"}]

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

1 files changed, 14 insertions, 15 deletions

diff --git a/src/irmd/oap.h b/src/irmd/oap.h
index 86f11e21..e9d7511b 100644
--- a/src/irmd/oap.h
+++ b/src/irmd/oap.h
@@ -40,21 +40,21 @@ int  oap_auth_add_ca_crt(void * crt);
 int  oap_auth_add_chain_crt(void * crt);
 
 /*
-* Prepare OAP request header for server, returns context
-* Passes client data for srv, returns srv data for client
-* rekey forces ephemeral server-encap KEX (no client-encap; preserves FS/PCS)
-*/
+ * Prepares the request header and returns the context. info holds the
+ * credentials we present, peer the name the server certificate must
+ * carry (NULL expects info->name); rekey forces an ephemeral KEX.
+ */
 int  oap_cli_prepare(void **                  ctx,
                      const struct name_info * info,
+                     const char *             peer,
                      buffer_t *               req_buf,
                      buffer_t                 data,
                      bool                     rekey);
 
 /*
- * Server processes header, creates response header, returns secret key.
- * data is in/out: input=srv data to send, output=cli data received.
- * rekey drops the cert and verifies against cached_crt; peer_crt (or NULL)
- * receives a copy of the peer cert to cache at the initial handshake.
+ * Answers the request header and returns the secret key. data is
+ * in/out; rekey verifies against cached_crt, and peer_crt takes a copy
+ * of the peer cert to cache at the initial handshake.
  */
 int  oap_srv_process(const struct name_info * info,
                      buffer_t                 req_buf,
@@ -70,13 +70,12 @@ int  oap_srv_process(const struct name_info * info,
  * cached_crt verifies a cert-less re-key; peer_crt (or NULL) receives a
  * copy of the peer cert to cache at the initial handshake.
  */
-int  oap_cli_complete(void *                   ctx,
-                      const struct name_info * info,
-                      buffer_t                 rsp_buf,
-                      buffer_t *               data,
-                      struct crypt_sk *        sk,
-                      const buffer_t *         cached_crt,
-                      buffer_t *               peer_crt);
+int  oap_cli_complete(void *            ctx,
+                      buffer_t          rsp_buf,
+                      buffer_t *        data,
+                      struct crypt_sk * sk,
+                      const buffer_t *  cached_crt,
+                      buffer_t *        peer_crt);
 
 /* Free OAP state (on failure before complete) */
 void oap_ctx_free(void * ctx);