RPKI protocol with one cache server per protocol

The RPKI protocol (RFC 6810) using the RTRLib
(http://rpki.realmv6.org/) that is integrated inside
the BIRD's code.

Implemeted transports are:
 - unprotected transport over TCP
 - secure transport over SSHv2

Example configuration of bird.conf:
  ...
  roa4 table r4;
  roa6 table r6;

  protocol rpki {
    debug all;

    # Import both IPv4 and IPv6 ROAs
    roa4 { table r4; };
    roa6 { table r6; };

    # Set cache server (validator) address,
    # overwrite default port 323
    remote "rpki-validator.realmv6.org" port 8282;

    # Overwrite default time intervals
    retry   10;         # Default 600 seconds
    refresh 60;         # Default 3600 seconds
    expire 600;         # Default 7200 seconds
  }

  protocol rpki {
    debug all;

    # Import only IPv4 routes
    roa4 { table r4; };

    # Set cache server address to localhost,
    # use default ports tcp => 323 or ssh => 22
    remote 127.0.0.1;

    # Use SSH transport instead of unprotected transport over TCP
    ssh encryption {
      bird private key "/home/birdgeek/.ssh/id_rsa";
      remote public key "/home/birdgeek/.ssh/known_hosts";
      user "birdgeek";
    };
  }
  ...

1 files changed, 135 insertions, 0 deletions

diff --git a/proto/rpki/transport.c b/proto/rpki/transport.c
new file mode 100644
index 00000000..182667be
--- /dev/null
+++ b/proto/rpki/transport.c
@@ -0,0 +1,135 @@
+/*
+ *	BIRD -- The Resource Public Key Infrastructure (RPKI) to Router Protocol
+ *
+ *	(c) 2015 CZ.NIC
+ *	(c) 2015 Pavel Tvrdik <pawel.tvrdik@gmail.com>
+ *
+ *	This file was a part of RTRlib: http://rpki.realmv6.org/
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include <sys/socket.h>
+#include <netdb.h>
+
+#include "rpki.h"
+#include "transport.h"
+#include "sysdep/unix/unix.h"
+
+/**
+ * rpki_hostname_autoresolv - auto-resolve an IP address from a hostname
+ * @host: domain name of host, e.g. "rpki-validator.realmv6.org"
+ *
+ * This function resolves an IP address from a hostname.
+ * Returns &ip_addr structure with IP address or |IPA_NONE|.
+ */
+static ip_addr
+rpki_hostname_autoresolv(const char *host)
+{
+  ip_addr addr = {};
+  struct addrinfo *res;
+  struct addrinfo hints = {
+      .ai_family = AF_UNSPEC,
+      .ai_socktype = SOCK_STREAM,
+      .ai_flags = AI_ADDRCONFIG,
+  };
+
+  if (!host)
+    return IPA_NONE;
+
+  int err_code = getaddrinfo(host, NULL, &hints, &res);
+  if (err_code != 0)
+  {
+    log(L_DEBUG "getaddrinfo failed: %s", gai_strerror(err_code));
+    return IPA_NONE;
+  }
+
+  sockaddr sa = {
+      .sa = *res->ai_addr,
+  };
+
+  uint unused;
+  sockaddr_read(&sa, res->ai_family, &addr, NULL, &unused);
+
+  freeaddrinfo(res);
+  return addr;
+}
+
+/**
+ * rpki_tr_open - prepare and open a socket connection
+ * @tr: initialized transport socket
+ *
+ * Prepare and open a socket connection specified by @tr that must be initialized before.
+ * This function ends with a calling the sk_open() function.
+ * Returns RPKI_TR_SUCCESS or RPKI_TR_ERROR.
+ */
+int
+rpki_tr_open(struct rpki_tr_sock *tr)
+{
+  struct rpki_cache *cache = tr->cache;
+  struct rpki_config *cf = (void *) cache->p->p.cf;
+
+  ASSERT(tr->sk == NULL);
+  tr->sk = sk_new(cache->pool);
+  sock *sk = tr->sk;
+
+  /* sk->type -1 is invalid value, a correct value MUST be set in the specific transport layer in open_fp() hook */
+  sk->type = -1;
+
+  sk->tx_hook = rpki_connected_hook;
+  sk->err_hook = rpki_err_hook;
+  sk->data = cache;
+  sk->daddr = cf->ip;
+  sk->dport = cf->port;
+  sk->host = cf->hostname;
+  sk->rbsize = RPKI_RX_BUFFER_SIZE;
+  sk->tbsize = RPKI_TX_BUFFER_SIZE;
+  sk->tos = IP_PREC_INTERNET_CONTROL;
+
+  if (ipa_zero2(sk->daddr) && sk->host)
+  {
+    sk->daddr = rpki_hostname_autoresolv(sk->host);
+    if (ipa_zero(sk->daddr))
+    {
+      CACHE_TRACE(D_EVENTS, cache, "Cannot resolve the hostname '%s'", sk->host);
+      return RPKI_TR_ERROR;
+    }
+  }
+
+  return tr->open_fp(tr);
+}
+
+/**
+ * rpki_tr_close - close socket and prepare it for possible next open
+ * @tr: successfully opened transport socket
+ *
+ * Close socket and free resources.
+ */
+void
+rpki_tr_close(struct rpki_tr_sock *tr)
+{
+  if (tr->ident)
+  {
+    mb_free((char *) tr->ident);
+    tr->ident = NULL;
+  }
+
+  if (tr->sk)
+  {
+    rfree(tr->sk);
+    tr->sk = NULL;
+  }
+}
+
+/**
+ * rpki_tr_ident - Returns a string identifier for the rpki transport socket
+ * @tr: successfully opened transport socket
+ *
+ * Returns a \0 terminated string identifier for the socket endpoint, e.g. "<host>:<port>".
+ * Memory is allocated inside @tr structure.
+ */
+inline const char *
+rpki_tr_ident(struct rpki_tr_sock *tr)
+{
+  return tr->ident_fp(tr);
+}