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, 133 insertions, 0 deletions

diff --git a/src/lib/serdes-irm.c b/src/lib/serdes-irm.c
index 1d9b4dec..20b25a1b 100644
--- a/src/lib/serdes-irm.c
+++ b/src/lib/serdes-irm.c
@@ -441,6 +441,7 @@ int proc_exit__irm_req_ser(buffer_t *   buf)
         return -ENOMEM;
 }
 
+/* data is borrowed from the caller; detach before free. */
 int ipcp_flow_req_arr__irm_req_ser(buffer_t *               buf,
                                    const buffer_t *         dst,
                                    const struct flow_info * flow,
@@ -494,6 +495,138 @@ int ipcp_flow_req_arr__irm_req_ser(buffer_t *               buf,
         return -ENOMEM;
 }
 
+static int __ep_flow_ser(buffer_t *               buf,
+                         const struct flow_info * flow,
+                         const buffer_t *         data,
+                         int                      response,
+                         const char *             dst,
+                         int                      code)
+{
+        irm_msg_t * msg;
+        size_t      len;
+        int         err = -ENOMEM;
+
+        msg = malloc(sizeof(*msg));
+        if (msg == NULL)
+                goto fail_malloc;
+
+        irm_msg__init(msg);
+
+        msg->code      = code;
+        msg->flow_info = flow_info_s_to_msg(flow);
+        if (msg->flow_info == NULL)
+                goto fail_msg;
+
+        if (dst != NULL) {
+                msg->dst = strdup(dst);
+                if (msg->dst == NULL)
+                        goto fail_msg;
+        }
+
+        if (data != NULL) {
+                msg->has_pk  = true;
+                msg->pk.len  = data->len;
+                msg->pk.data = data->data;
+        }
+
+        msg->has_response = true;
+        msg->response     = response;
+
+        len = irm_msg__get_packed_size(msg);
+        if (len == 0 || len > buf->len)
+                goto fail_msg;
+
+        buf->len = len;
+
+        irm_msg__pack(msg, buf->data);
+
+        err = 0;
+ fail_msg:
+        msg->pk.len  = 0;
+        msg->pk.data = NULL;
+
+        irm_msg__free_unpacked(msg, NULL);
+ fail_malloc:
+        return err;
+}
+
+int poa_flow_alloc__irm_req_ser(buffer_t *               buf,
+                                const struct flow_info * flow,
+                                const char *             dst)
+{
+        return __ep_flow_ser(buf, flow, NULL, 0, dst,
+                             IRM_MSG_CODE__IRM_POA_FLOW_ALLOC);
+}
+
+int poa_flow_alloc_r__irm_req_ser(buffer_t *               buf,
+                                  const struct flow_info * flow,
+                                  const buffer_t *         data,
+                                  int                      response)
+{
+        return __ep_flow_ser(buf, flow, data, response, NULL,
+                             IRM_MSG_CODE__IRM_POA_FLOW_ALLOC_R);
+}
+
+int ipcp_poa_flow_req_arr__irm_req_ser(buffer_t *               buf,
+                                       const struct flow_info * flow,
+                                       const buffer_t *         data)
+{
+        return __ep_flow_ser(buf, flow, data, 0, NULL,
+                             IRM_MSG_CODE__IPCP_POA_FLOW_REQ_ARR);
+}
+
+int poa_flow__irm_result_des(buffer_t *         buf,
+                             struct flow_info * flow,
+                             buffer_t *         data)
+{
+        irm_msg_t * msg;
+        int         err;
+
+        msg = irm_msg__unpack(NULL, buf->len, buf->data);
+        if (msg == NULL) {
+                err = -EIRMD;
+                goto fail_msg;
+        }
+
+        if (!msg->has_result) {
+                err = -EIRMD;
+                goto fail;
+        }
+
+        if (msg->result < 0) {
+                err = msg->result;
+                goto fail;
+        }
+
+        if (msg->flow_info == NULL) {
+                err = -EBADF;
+                goto fail;
+        }
+
+        *flow = flow_info_msg_to_s(msg->flow_info);
+
+        clrbuf(*data);
+
+        if (msg->has_pk && msg->pk.len > 0) {
+                data->data = malloc(msg->pk.len);
+                if (data->data == NULL) {
+                        err = -ENOMEM;
+                        goto fail;
+                }
+                memcpy(data->data, msg->pk.data, msg->pk.len);
+
+                data->len = msg->pk.len;
+        }
+
+        irm_msg__free_unpacked(msg, NULL);
+
+        return 0;
+ fail:
+        irm_msg__free_unpacked(msg, NULL);
+ fail_msg:
+        return err;
+}
+
 int ipcp_flow_update_arr__irm_req_ser(buffer_t *               buf,
                                       const struct flow_info * flow,
                                       const buffer_t *         data)