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, 307 insertions, 0 deletions

diff --git a/src/lib/tests/poa_test.c b/src/lib/tests/poa_test.c
new file mode 100644
index 00000000..99886769
--- /dev/null
+++ b/src/lib/tests/poa_test.c
@@ -0,0 +1,307 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2026
+ *
+ * Flow PoA tests
+ *
+ *    Dimitri Staessens <dimitri@ouroboros.rocks>
+ *    Sander Vrijders   <sander@ouroboros.rocks>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200809L
+#endif
+
+#include <test/test.h>
+
+#include "poa/addr.c"
+#ifdef HAVE_RAW_SOCKETS
+#include "poa/eth.c"
+#endif
+
+#include <arpa/inet.h>
+#include <stdio.h>
+
+#ifdef HAVE_RAW_SOCKETS
+static const uint8_t eth_our_mac[POA_MAC_SIZE] =
+        { 0x02, 0x00, 0x00, 0x00, 0x00, 0x01 };
+static const uint8_t eth_far_mac[POA_MAC_SIZE] =
+        { 0x02, 0x00, 0x00, 0x00, 0x00, 0x02 };
+static const uint8_t eth_bc_mac[POA_MAC_SIZE] =
+        { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+#endif
+
+/* PoA core stubs: the reader threads never run in this test. */
+void poa_rx_pkt(struct poa *         poa,
+                uint32_t             eid,
+                struct ssm_pk_buff * spb)
+{
+        (void) poa;
+        (void) eid;
+        (void) spb;
+}
+
+void poa_rx_mgmt(struct poa *            poa,
+                 const struct poa_addr * src,
+                 const uint8_t *         buf,
+                 size_t                  len)
+{
+        (void) poa;
+        (void) src;
+        (void) buf;
+        (void) len;
+}
+
+int poa_spb_reserve(struct ssm_pk_buff ** spb,
+                    size_t                len)
+{
+        (void) spb;
+        (void) len;
+
+        return -1;
+}
+
+size_t poa_link_updown(int  ifindex,
+                       bool up)
+{
+        (void) ifindex;
+        (void) up;
+
+        return 0;
+}
+
+bool poa_has_name(const uint8_t * hash)
+{
+        (void) hash;
+
+        return false;
+}
+
+int poa_bcast_mgmt(const struct poa_addr * dst,
+                   const uint8_t *         buf,
+                   size_t                  len)
+{
+        (void) dst;
+        (void) buf;
+        (void) len;
+
+        return 0;
+}
+
+static void udp4_addr(struct poa_addr * addr,
+                      const char *      ip,
+                      uint16_t          port)
+{
+        memset(addr, 0, sizeof(*addr));
+
+        addr->type      = POA_UDP4;
+        addr->udp4.port = port;
+
+        inet_pton(AF_INET, ip, &addr->udp4.ip_addr);
+}
+
+static int test_poa_addr_cmp(void)
+{
+        struct poa_addr a;
+        struct poa_addr b;
+
+        TEST_START();
+
+        udp4_addr(&a, "10.0.0.10", 3435);
+        udp4_addr(&b, "10.0.0.10", 3435);
+
+        if (poa_addr_cmp(&a, &b) != 0) {
+                printf("Identical addresses did not match.\n");
+                goto fail;
+        }
+
+        udp4_addr(&b, "10.0.0.10", 3436);
+
+        if (poa_addr_cmp(&a, &b) == 0) {
+                printf("Addresses with a different port matched.\n");
+                goto fail;
+        }
+
+        udp4_addr(&b, "10.0.0.11", 3435);
+
+        if (poa_addr_cmp(&a, &b) == 0) {
+                printf("Addresses with a different ip matched.\n");
+                goto fail;
+        }
+
+        b.type = POA_UDP6;
+        if (poa_addr_cmp(&a, &b) == 0) {
+                printf("Addresses of a different type matched.\n");
+                goto fail;
+        }
+
+        TEST_SUCCESS();
+
+        return TEST_RC_SUCCESS;
+ fail:
+        TEST_FAIL();
+        return TEST_RC_FAIL;
+}
+
+static int test_poa_mgmt_msg_qos(void)
+{
+        struct poa_mgmt_msg msg;
+        qosspec_t           qs;
+
+        TEST_START();
+
+        poa_mgmt_msg_ser(&msg, POA_FLOW_REQ, 1, 2, qos_stream, 0, 0);
+
+        if (msg.code != POA_FLOW_REQ) {
+                printf("Wrong code in management message.\n");
+                goto fail;
+        }
+
+        if (ntoh32(msg.s_eid) != 1 || ntoh32(msg.d_eid) != 2) {
+                printf("Wrong PoA ids in management message.\n");
+                goto fail;
+        }
+
+        memset(&qs, 0, sizeof(qs));
+
+        poa_mgmt_msg_qos(&msg, &qs);
+
+        if (memcmp(&qs, &qos_stream, sizeof(qs)) != 0) {
+                printf("QoS did not survive the management message.\n");
+                goto fail;
+        }
+
+        TEST_SUCCESS();
+
+        return TEST_RC_SUCCESS;
+ fail:
+        TEST_FAIL();
+        return TEST_RC_FAIL;
+}
+
+#ifdef HAVE_RAW_SOCKETS
+
+static void eth_fake_priv(struct eth_priv * priv,
+                          struct poa *      e)
+{
+        memset(priv, 0, sizeof(*priv));
+        memset(e, 0, sizeof(*e));
+
+        e->type = POA_ETH;
+
+        strcpy(e->local.eth.src.dev, "test0");
+
+        priv->poa       = e;
+        priv->ethertype = htons(0xA000);
+        priv->mtu       = 1500;
+
+        memcpy(priv->hw_addr, eth_our_mac, POA_MAC_SIZE);
+}
+
+static int test_eth_frame(void)
+{
+        struct eth_priv  priv;
+        struct poa       e;
+        uint8_t          buf[64];
+        struct eth_hdr * hdr = (struct eth_hdr *) buf;
+        const char *     body = "hello";
+        size_t           n;
+        size_t           plen;
+        uint32_t         eid;
+
+        TEST_START();
+
+        eth_fake_priv(&priv, &e);
+
+        eth_hdr_ser(&priv, hdr, eth_our_mac, 7, strlen(body));
+
+        memcpy(buf + ETH_HDR_TOT_SIZE, body, strlen(body));
+
+        n = ETH_HDR_TOT_SIZE + strlen(body);
+        if (frame_parse(&priv, buf, n, &eid, &plen) < 0) {
+                printf("Failed to parse a valid frame.\n");
+                goto fail;
+        }
+
+        if (eid != 7 || plen != strlen(body)) {
+                printf("Expected eid 7 len %zu, got %u len %zu.\n",
+                       strlen(body), eid, plen);
+                goto fail;
+        }
+
+        hdr->poa.hcs ^= 0xFF;
+
+        if (frame_parse(&priv, buf, n, &eid, &plen) == 0) {
+                printf("Accepted a corrupt header checksum.\n");
+                goto fail;
+        }
+
+        hdr->poa.hcs ^= 0xFF;
+        hdr->ethertype ^= 0xFF;
+
+        if (frame_parse(&priv, buf, n, &eid, &plen) == 0) {
+                printf("Accepted a foreign Ethertype.\n");
+                goto fail;
+        }
+
+        hdr->ethertype ^= 0xFF;
+
+        if (frame_parse(&priv, buf, ETH_HDR_SIZE + 2, &eid, &plen) == 0) {
+                printf("Accepted a truncated frame.\n");
+                goto fail;
+        }
+
+        eth_hdr_ser(&priv, hdr, eth_far_mac, 7, strlen(body));
+
+        if (frame_parse(&priv, buf, n, &eid, &plen) == 0) {
+                printf("Accepted a frame for another host.\n");
+                goto fail;
+        }
+
+        eth_hdr_ser(&priv, hdr, eth_bc_mac, 7, strlen(body));
+
+        if (frame_parse(&priv, buf, n, &eid, &plen) < 0) {
+                printf("Rejected a broadcast frame.\n");
+                goto fail;
+        }
+
+        TEST_SUCCESS();
+
+        return TEST_RC_SUCCESS;
+ fail:
+        TEST_FAIL();
+        return TEST_RC_FAIL;
+}
+
+#endif /* HAVE_RAW_SOCKETS */
+
+int poa_test(int     argc,
+             char ** argv)
+{
+        int ret = 0;
+
+        (void) argc;
+        (void) argv;
+
+        ret |= test_poa_addr_cmp();
+        ret |= test_poa_mgmt_msg_qos();
+#ifdef HAVE_RAW_SOCKETS
+        ret |= test_eth_frame();
+#endif
+
+        return ret;
+}