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 +1,211 @@
+//    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
+
+#ifndef OPENVPN_NETCONF_LINUX_GW_H
+#define OPENVPN_NETCONF_LINUX_GW_H
+
+#include <string>
+#include <limits>
+
+#include <openvpn/common/exception.hpp>
+#include <openvpn/common/number.hpp>
+#include <openvpn/common/split.hpp>
+#include <openvpn/common/splitlines.hpp>
+#include <openvpn/common/process.hpp>
+#include <openvpn/addr/route.hpp>
+
+namespace openvpn {
+  class LinuxGW
+  {
+  public:
+    OPENVPN_EXCEPTION(linux_gw_error);
+
+    LinuxGW(const std::string& ip_route_show_txt, const bool ignore_errors)
+    {
+      int best_metric = std::numeric_limits<int>::max();
+
+      SplitLines sl(ip_route_show_txt);
+      while (sl())
+	{
+	  const std::string& line = sl.line_ref();
+
+	  try {
+	    // parse an output line generated by "ip [-6] route show"
+	    const std::vector<std::string> v = Split::by_space<std::vector<std::string>, NullLex, SpaceMatch, Split::NullLimit>(line);
+
+	    // blank line?
+	    if (v.empty())
+	      continue;
+
+	    // only interested in default routes
+	    if (v[0] != "default")
+	      continue;
+
+	    // parse out route information
+	    enum RouteInfo {
+	      INITIAL,
+	      VIA,
+	      DEV,
+	      METRIC,
+	    };
+
+	    std::string d;
+	    IP::Addr a;
+	    int m = std::numeric_limits<int>::max();
+
+	    RouteInfo ri = INITIAL;
+	    for (const auto &term : v)
+	      {
+		switch (ri)
+		  {
+		  case INITIAL:
+		    if (term == "via")
+		      ri = VIA;
+		    else if (term == "dev")
+		      ri = DEV;
+		    else if (term == "metric")
+		      ri = METRIC;
+		    else
+		      ri = INITIAL;
+		    break;
+		  case VIA:
+		    a = IP::Addr(term, "via");
+		    ri = INITIAL;
+		    break;
+		  case DEV:
+		    d = validate_dev(term);
+		    ri = INITIAL;
+		    break;
+		  case METRIC:
+		    m = parse_number_throw<int>(term, "bad metric");
+		    ri = INITIAL;
+		    break;
+		  }
+	      }
+
+	    // best metric?
+	    if (m < best_metric || best_metric == std::numeric_limits<int>::max())
+	      {
+		best_metric = m;
+		dev_ = d;
+		addr_ = a;
+	      }
+	  }
+	  catch (const std::exception& e)
+	    {
+	      if (!ignore_errors)
+		OPENVPN_THROW(linux_gw_error, "error parsing line: " << line << " : " << e.what());
+	    }
+	}
+    }
+
+    static std::string ip_route_show(const bool ipv6)
+    {
+      RedirectPipe::InOut pipe;
+      Argv argv;
+      argv.emplace_back("/sbin/ip");
+      if (ipv6)
+	argv.emplace_back("-6");
+      argv.emplace_back("route");
+      argv.emplace_back("show");
+      const int status = system_cmd(argv[0], argv, nullptr, pipe, 0);
+      if (status != 0)
+	OPENVPN_THROW(linux_gw_error, "command returned error status " << status << " : " << argv.to_string());
+      return pipe.out;
+    }
+
+    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:
+    std::string validate_dev(const std::string& dev)
+    {
+      if (dev.empty())
+	OPENVPN_THROW_EXCEPTION("dev is empty");
+      return dev;
+    }
+
+    std::string dev_;
+    IP::Addr addr_;
+  };
+
+  struct LinuxGW46
+  {
+    LinuxGW46(const bool ignore_errors)
+      : v4(LinuxGW::ip_route_show(false), ignore_errors),
+	v6(LinuxGW::ip_route_show(true), ignore_errors)
+    {
+    }
+
+    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 LinuxGW::linux_gw_error("cannot determine gateway interface");
+    }
+
+    LinuxGW v4;
+    LinuxGW v6;
+  };
+}
+
+#endif