Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

2026-04-24 00:00:05 +08:00 · 2020-02-24 14:43:11 +03:00
parent 133b3756e6 86cc97e55f
commit 32f1555929
655 changed files with 146468 additions and 0 deletions
@@ -0,0 +1,159 @@
+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    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 Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+// Find default gateways on Linux using ip route command
+
+#pragma once
+
+#include <string>
+
+#include <openvpn/common/exception.hpp>
+#include <openvpn/addr/ip.hpp>
+#include <openvpn/addr/ipv4.hpp>
+#include <openvpn/addr/ipv6.hpp>
+#include <openvpn/tun/linux/client/sitnl.hpp>
+
+namespace openvpn {
+  class LinuxGWNetlink
+  {
+  public:
+    OPENVPN_EXCEPTION(linux_gw_netlink_error);
+
+    /**
+     * Provides gateway which is used to reach given address
+     *
+     * @param addr address which we want to reach
+     * @param iface_to_ignore this allows to exclude certain interface
+     * from discovered gateways. Used when we want to exclude VPN interface
+     * when there is active VPN connection with redirected default gateway
+     *
+     * @param ipv6 true if address is IPv6
+     */
+    LinuxGWNetlink(const std::string& addr, const std::string& iface_to_ignore, bool ipv6)
+    {
+      try
+      {
+	if (ipv6)
+	{
+	  IPv6::Addr addr6;
+
+	  if (TunNetlink::SITNL::net_route_best_gw(IP::Route6::from_string(addr),
+						   addr6, dev_, iface_to_ignore) < 0)
+	  {
+	    OPENVPN_THROW(linux_gw_netlink_error,
+			  "error retrieving default IPv6 GW");
+	  }
+
+	  addr_ = IP::Addr::from_ipv6(addr6);
+	}
+	else
+	{
+	  IPv4::Addr addr4;
+
+	  if (TunNetlink::SITNL::net_route_best_gw(IP::Route4::from_string(addr),
+						   addr4, dev_, iface_to_ignore) < 0)
+	  {
+	    OPENVPN_THROW(linux_gw_netlink_error,
+			  "error retrieving default IPv4 GW");
+	  }
+
+	  addr_ = IP::Addr::from_ipv4(addr4);
+	}
+      } catch (...)
+      {
+	/* nothing to do. just leave default GW unassigned */
+      }
+    }
+
+    const std::string& dev() const
+    {
+      return dev_;
+    }
+
+    const IP::Addr& addr() const
+    {
+      return addr_;
+    }
+
+    bool defined() const
+    {
+      return !dev_.empty() && addr_.defined();
+    }
+
+    std::string to_string() const
+    {
+      return dev_ + '/' + addr_.to_string();
+    }
+
+  private:
+    IP::Addr addr_;
+    std::string dev_;
+  };
+
+  /**
+   * Provides IPv4/6 gateway which is used to reach given address
+   *
+   * @param iface_to_ignore this allows to exclude certain interface
+   * from discovered gateways. Used when we want to exclude VPN interface
+   * when there is active VPN connection with redirected default gateway
+   * @param addr address which we want to reach
+   */
+  struct LinuxGW46Netlink
+  {
+    LinuxGW46Netlink(const std::string& iface_to_ignore, const std::string& addr = "")
+      : v4(addr.empty() ? IPv4::Addr::from_zero().to_string() : addr, iface_to_ignore, false),
+        v6(addr.empty() ? IPv6::Addr::from_zero().to_string() : addr, iface_to_ignore, true)
+    {
+    }
+
+    std::string to_string() const
+    {
+      std::string ret = "[";
+      if (v4.defined())
+	{
+	  ret += "4:";
+	  ret += v4.to_string();
+	}
+      if (v6.defined())
+	{
+	  if (v4.defined())
+	    ret += ' ';
+	  ret += "6:";
+	  ret += v6.to_string();
+	}
+      ret += "]";
+      return ret;
+    }
+
+    std::string dev() const
+    {
+      if (v4.defined())
+	return v4.dev();
+      else if (v6.defined())
+	return v6.dev();
+      else
+	throw LinuxGWNetlink::linux_gw_netlink_error("cannot determine gateway interface");
+    }
+
+    LinuxGWNetlink v4;
+    LinuxGWNetlink v6;
+  };
+}