sitnl: allow user to configure custom metric for routes

Until now sitnl was just default to metric 0 when installing routes,
while ignoring any value that may have been passed by the user.

Extend logic to properly accept a user value.

Signed-off-by: Antonio Quartulli <antonio@openvpn.net>

openvpn/tun/linux/client/tunnetlink.hpp

@@ -319,10 +319,12 @@ struct NetlinkRoute4 : public Action
  int prefixlen_arg,
  IPv4::Addr &gw_arg,
  std::string dev_arg,
+ int metric_arg,
  bool add_arg)
  : route(dst_arg, prefixlen_arg),
  gw(gw_arg),
  dev(dev_arg),
+ metric(metric_arg),
  add(add_arg)
  {
  }
@@ -333,6 +335,7 @@ struct NetlinkRoute4 : public Action
  ret->route = route;
  ret->gw = gw;
  ret->dev = dev;
+ ret->metric = metric;
  return ret;
  }
 
@@ -347,11 +350,11 @@ struct NetlinkRoute4 : public Action
  int ret;
  if (add)
  {
- ret = SITNL::net_route_add(route, gw, dev, 0, 0);
+ ret = SITNL::net_route_add(route, gw, dev, 0, metric);
  }
  else
  {
- ret = SITNL::net_route_del(route, gw, dev, 0, 0);
+ ret = SITNL::net_route_del(route, gw, dev, 0, metric);
  }
 
  if (ret)
@@ -365,13 +368,14 @@ struct NetlinkRoute4 : public Action
  {
  std::ostringstream os;
  os << "netlink route " << (add ? "add" : "del") << " dev " << dev << " "
- << route << " via " << gw.to_string();
+ << route << " via " << gw.to_string() << " metric " << metric;
  return os.str();
  }
 
  IP::Route4 route;
  IPv4::Addr gw;
  std::string dev;
+ int metric = -1;
  bool add = true;
 };
 
@@ -387,10 +391,12 @@ struct NetlinkRoute6 : public Action
  int prefixlen_arg,
  IPv6::Addr &gw_arg,
  std::string dev_arg,
+ int metric_arg,
  bool add_arg)
  : route(dst_arg, prefixlen_arg),
  gw(gw_arg),
  dev(dev_arg),
+ metric(metric_arg),
  add(add_arg)
  {
  }
@@ -401,6 +407,7 @@ struct NetlinkRoute6 : public Action
  ret->route = route;
  ret->gw = gw;
  ret->dev = dev;
+ ret->metric = metric;
  return ret;
  }
 
@@ -415,11 +422,11 @@ struct NetlinkRoute6 : public Action
  int ret;
  if (add)
  {
- ret = SITNL::net_route_add(route, gw, dev, 0, 0);
+ ret = SITNL::net_route_add(route, gw, dev, 0, metric);
  }
  else
  {
- ret = SITNL::net_route_del(route, gw, dev, 0, 0);
+ ret = SITNL::net_route_del(route, gw, dev, 0, metric);
  }
 
  if (ret)
@@ -433,13 +440,14 @@ struct NetlinkRoute6 : public Action
  {
  std::ostringstream os;
  os << "netlink route " << (add ? "add" : "del") << " dev " << dev << " "
- << route << " via " << gw.to_string();
+ << route << " via " << gw.to_string() << " metric " << metric;
  return os.str();
  }
 
  IP::Route6 route;
  IPv6::Addr gw;
  std::string dev;
+ int metric = -1;
  bool add = true;
 };
 
@@ -517,6 +525,7 @@ inline void add_del_route(const std::string &addr_str,
  const int prefix_len,
  const std::string &gateway_str,
  const std::string &dev,
+ const int metric,
  const unsigned int flags,
  std::vector<IP::Route> *rtvec,
  Action::Ptr &create,
@@ -536,6 +545,7 @@ inline void add_del_route(const std::string &addr_str,
  add->route.prefix_len = prefix_len;
  add->gw = IPv6::Addr::from_string(gateway_str);
  add->dev = dev;
+ add->metric = metric;
  add->add = true;
 
  create = add;
@@ -562,6 +572,7 @@ inline void add_del_route(const std::string &addr_str,
  add->route.prefix_len = prefix_len;
  add->gw = IPv4::Addr::from_string(gateway_str);
  add->dev = dev;
+ add->metric = metric;
  add->add = true;
 
  create = add;
@@ -580,13 +591,14 @@ inline void add_del_route(const std::string &addr_str,
  const int prefix_len,
  const std::string &gateway_str,
  const std::string &dev,
+ const int metric,
  const unsigned int flags, // add interface route to rtvec if defined
  std::vector<IP::Route> *rtvec,
  ActionList &create,
  ActionList &destroy)
 {
  Action::Ptr c, d;
- add_del_route(addr_str, prefix_len, gateway_str, dev, flags, rtvec, c, d);
+ add_del_route(addr_str, prefix_len, gateway_str, dev, metric, flags, rtvec, c, d);
  create.add(c);
  destroy.add(d);
 }
@@ -648,6 +660,7 @@ inline void iface_config(const std::string &iface_name,
  local4->prefix_length,
  local4->address,
  iface_name,
+ 0,
  R_ADD_DCO,
  rtvec,
  create,
@@ -675,6 +688,7 @@ inline void iface_config(const std::string &iface_name,
  local6->prefix_length,
  local6->address,
  iface_name,
+ 0,
  R_ADD_DCO | R_IPv6,
  rtvec,
  create,
@@ -711,6 +725,7 @@ struct TunMethods
  route.prefix_length,
  local6->gateway,
  iface_name,
+ route.metric,
  R_ADD_ALL | R_IPv6,
  rtvec,
  create,
@@ -723,6 +738,7 @@ struct TunMethods
  route.prefix_length,
  local4->gateway,
  iface_name,
+ route.metric,
  R_ADD_ALL,
  rtvec,
  create,
@@ -751,6 +767,7 @@ struct TunMethods
  route.prefix_length,
  gw.v4.addr().to_string(),
  gw.v4.dev(),
+ route.metric,
  R_ADD_SYS,
  rtvec,
  create,
@@ -779,8 +796,8 @@ struct TunMethods
  destroy);
  }
 
- add_del_route("0.0.0.0", 1, local4->gateway, iface_name, R_ADD_ALL, rtvec, create, destroy);
- add_del_route("128.0.0.0", 1, local4->gateway, iface_name, R_ADD_ALL, rtvec, create, destroy);
+ add_del_route("0.0.0.0", 1, local4->gateway, iface_name, 0, R_ADD_ALL, rtvec, create, destroy);
+ add_del_route("128.0.0.0", 1, local4->gateway, iface_name, 0, R_ADD_ALL, rtvec, create, destroy);
  }
 
  // Process IPv6 redirect-gateway
@@ -799,8 +816,8 @@ struct TunMethods
  destroy);
  }
 
- add_del_route("0000::", 1, local6->gateway, iface_name, R_ADD_ALL | R_IPv6, rtvec, create, destroy);
- add_del_route("8000::", 1, local6->gateway, iface_name, R_ADD_ALL | R_IPv6, rtvec, create, destroy);
+ add_del_route("0000::", 1, local6->gateway, iface_name, 0, R_ADD_ALL | R_IPv6, rtvec, create, destroy);
+ add_del_route("8000::", 1, local6->gateway, iface_name, 0, R_ADD_ALL | R_IPv6, rtvec, create, destroy);
  }
  }
 
@@ -823,6 +840,7 @@ struct TunMethods
  32,
  gw.v4.addr().to_string(),
  gw.dev(),
+ 0,
  R_ADD_SYS,
  rtvec,
  create,
@@ -833,6 +851,7 @@ struct TunMethods
  128,
  gw.v6.addr().to_string(),
  gw.dev(),
+ 0,
  R_IPv6 | R_ADD_SYS,
  rtvec,
  create,