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, 37 insertions, 4 deletions

diff --git a/src/tools/irm/irm_utils.h b/src/tools/irm/irm_utils.h
index c6d4bf18..3760b4e4 100644
--- a/src/tools/irm/irm_utils.h
+++ b/src/tools/irm/irm_utils.h
@@ -79,10 +79,43 @@
 #ifndef OUROBOROS_TOOLS_IRM_UTILS_H
 #define OUROBOROS_TOOLS_IRM_UTILS_H
 
-int matches(const char * cmd,
-            const char * pattern);
+#include <ouroboros/ipcp.h>
 
-int wildcard_match(const char * pattern,
-                   const char * string);
+#include <arpa/inet.h>
+
+#include <stdint.h>
+
+int  matches(const char * cmd,
+             const char * pattern);
+
+int  wildcard_match(const char * pattern,
+                    const char * string);
+
+/* Fill one PoA to attach or detach: an address or a device. */
+int  poa_spec_set(struct poa_spec * poa,
+                  const char *      udpstr,
+                  const char *      devstr,
+                  uint16_t          ethertype);
+
+/* Fill a peer PoA address; a host name is resolved by the IRMd. */
+int  poa_addr_set_udp(struct poa_addr * addr,
+                      const char *      str);
+
+/* Fits "eth <dev> 0x<type>", the longest PoA rendering. */
+/* Matches src/ipcpd/ipcp.c; keep in sync. */
+#define POA_STRLEN (DEV_NAME_SIZE + 11)
+
+/* Names a PoA the way the IPCP logs it. */
+void poa_spec_str(const struct poa_spec * poa,
+                  char *                  buf,
+                  size_t                  len);
+
+int  poa_addr_set_eth(struct poa_addr * addr,
+                      const char *      devstr,
+                      uint16_t          ethertype);
+
+/* Parses a hex ethertype; rejects garbage and out-of-range values. */
+int  parse_ethertype(const char * str,
+                     uint16_t *   ethertype);
 
 #endif /* OUROBOROS_TOOLS_IRM_UTILS_H */