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, 232 insertions, 1 deletions

diff --git a/src/tools/irm/irm_utils.c b/src/tools/irm/irm_utils.c
index 69873097..c43accec 100644
--- a/src/tools/irm/irm_utils.c
+++ b/src/tools/irm/irm_utils.c
@@ -77,10 +77,21 @@
  */
 
 
-#include <string.h>
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200809L
+#endif
+
+#include <ouroboros/ipcp.h>
 
 #include "irm_utils.h"
 
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
 int matches(const char * cmd,
             const char * pattern)
 {
@@ -123,3 +134,223 @@ int wildcard_match(const char * pattern,
                 }
         }
 }
+
+/* Splits "<addr>[:<port>]"; bare IPv6 needs no brackets. */
+static int parse_udp_str(const char * str,
+                         char *       host,
+                         int *        port)
+{
+        struct in6_addr v6;
+        char            buf[POA_HOST_STRLEN + 1];
+        char *          p;
+        char *          end;
+        long            n;
+
+        *port = POA_UDP_PORT;
+
+        if (strlen(str) > POA_HOST_STRLEN)
+                goto fail;
+
+        strcpy(buf, str);
+
+        if (buf[0] == '[') {
+                p = strchr(buf, ']');
+                if (p == NULL)
+                        goto fail;
+
+                *p++ = '\0';
+
+                strcpy(host, buf + 1);
+
+                if (*p == '\0')
+                        return 0;
+
+                if (*p != ':')
+                        goto fail;
+
+                ++p;
+        } else if (inet_pton(AF_INET6, buf, &v6) == 1) {
+                strcpy(host, buf);
+                return 0;
+        } else {
+                p = strrchr(buf, ':');
+                if (p == NULL) {
+                        strcpy(host, buf);
+                        return 0;
+                }
+
+                *p++ = '\0';
+
+                strcpy(host, buf);
+        }
+
+        n = strtol(p, &end, 10);
+        if (*p == '\0' || *end != '\0' || n < 1 || n > 65535)
+                goto fail;
+
+        *port = (int) n;
+
+        return 0;
+ fail:
+        printf("Invalid UDP address: \"%s\".\n", str);
+        return -1;
+}
+
+/* An unresolved name is left for the IRMd, which picks the family. */
+int poa_addr_set_udp(struct poa_addr * addr,
+                     const char *      str)
+{
+        char host[POA_HOST_STRLEN + 1];
+        int  port;
+
+        if (parse_udp_str(str, host, &port) < 0)
+                return -1;
+
+        if (inet_pton(AF_INET, host, &addr->udp4.ip_addr) == 1) {
+                addr->type      = POA_UDP4;
+                addr->udp4.port = port;
+                return 0;
+        }
+
+        if (inet_pton(AF_INET6, host, &addr->udp6.ip_addr) == 1) {
+                addr->type      = POA_UDP6;
+                addr->udp6.port = port;
+                return 0;
+        }
+
+        addr->type      = POA_UDP;
+        addr->udp4.port = port;
+
+        strcpy(addr->hostname, host);
+
+        return 0;
+}
+
+/*
+ * Parses a hex ethertype; rejects garbage and out-of-range values.
+ * Overflow clamps to LONG_MAX and lands in the range check.
+ */
+int parse_ethertype(const char * str,
+                    uint16_t *   ethertype)
+{
+        char * end;
+        long   val;
+
+        val = strtol(str, &end, 16);
+
+        if (end == str || *end != '\0')
+                return -1;
+
+        if (val < 0 || val > 0xFFFF)
+                return -1;
+
+        *ethertype = (uint16_t) val;
+
+        return 0;
+}
+
+int poa_addr_set_eth(struct poa_addr * addr,
+                     const char *      devstr,
+                     uint16_t          ethertype)
+{
+        addr->type = POA_ETH;
+
+        addr->eth.src.ethertype = ethertype;
+        addr->eth.dst.ethertype = ethertype;
+
+        if (devstr != NULL) {
+                if (strlen(devstr) > DEV_NAME_SIZE) {
+                        printf("Invalid device name: \"%s\".\n", devstr);
+                        return -1;
+                }
+
+                strcpy(addr->eth.src.dev, devstr);
+        }
+
+        return 0;
+}
+
+/* Matches src/ipcpd/ipcp.c; keep in sync. */
+void poa_spec_str(const struct poa_spec * poa,
+                  char *                  buf,
+                  size_t                  len)
+{
+        char addr[INET6_ADDRSTRLEN];
+
+        switch (poa->type) {
+        case POA_UDP4:
+                if (inet_ntop(AF_INET, &poa->udp4.ip_addr,
+                              addr, sizeof(addr)) == NULL)
+                        break;
+
+                snprintf(buf, len, "udp4 %s:%u", addr, poa->udp4.port);
+                return;
+        case POA_UDP6:
+                if (inet_ntop(AF_INET6, &poa->udp6.ip_addr,
+                              addr, sizeof(addr)) == NULL)
+                        break;
+
+                snprintf(buf, len, "udp6 [%s]:%u", addr, poa->udp6.port);
+                return;
+        case POA_ETH:
+                snprintf(buf, len, "eth %s 0x%04X", poa->eth.dev,
+                         poa->eth.ethertype);
+                return;
+        default:
+                break;
+        }
+
+        snprintf(buf, len, "(unknown)");
+}
+
+int poa_spec_set(struct poa_spec * poa,
+                 const char *      udpstr,
+                 const char *      devstr,
+                 uint16_t          ethertype)
+{
+        char host[POA_HOST_STRLEN + 1];
+        int  port;
+
+        memset(poa, 0, sizeof(*poa));
+
+        if ((udpstr != NULL) + (devstr != NULL) > 1) {
+                printf("A PoA is an address or a device.\n");
+                return -1;
+        }
+
+        if (udpstr != NULL) {
+                if (parse_udp_str(udpstr, host, &port) < 0)
+                        return -1;
+
+                if (inet_pton(AF_INET, host, &poa->udp4.ip_addr) == 1) {
+                        poa->type      = POA_UDP4;
+                        poa->udp4.port = port;
+                        return 0;
+                }
+
+                if (inet_pton(AF_INET6, host, &poa->udp6.ip_addr) == 1) {
+                        poa->type      = POA_UDP6;
+                        poa->udp6.port = port;
+                        return 0;
+                }
+
+                printf("Invalid IP address: \"%s\".\n", udpstr);
+                return -1;
+        }
+
+        if (devstr != NULL) {
+                if (strlen(devstr) > DEV_NAME_SIZE) {
+                        printf("Invalid device name: \"%s\".\n", devstr);
+                        return -1;
+                }
+
+                poa->type          = POA_ETH;
+                poa->eth.ethertype = ethertype;
+
+                strcpy(poa->eth.dev, devstr);
+
+                return 0;
+        }
+
+        return -1;
+}