Added a promiscuous mode that allows the proxy interface to also respond to queries send from the gateway (for instance when it needs to route to a WAN address thats local)

ndppd.conf-dist

@@ -24,11 +24,19 @@ proxy eth0 {
    timeout 500   
 
    # autowire <yes|no|true|false>
-   # Controls whether whether ndppd will automatically create host entries
+   # Controls whether ndppd will automatically create host entries
    # in the routing tables when it receives Neighbor Advertisements on a
    # listening interface. The the default value is no.
 
    autowire no
+
+   # promiscuous <yes|no|true|false>
+   # Controls whether ndppd will put the proxy listening interface into promiscuous
+   # mode and hence will react to inbound and outbound NDP commands. This is
+   # required for machines behind the gateway to talk to each other in more
+   # complex topology scenarios. The the default value is no.
+
+   promiscuous no
    
    # ttl <integer>
    # Controls how long a valid or invalid entry remains in the cache, in 

ndppd.conf.5

@@ -54,6 +54,14 @@ Controls whether
 will automatically create host entries in the routing tables when
 .B ndppd receives Neighbor Advertisements on a listening interface.
 The default value is no.
+.IP "promiscuous <yes|no>"
+Controls whether
+.B ndppd
+will put the proxy listening interface into promiscuous mode and
+hence will react to inbound and outbound NDP commands. This is
+required for machines behind the gateway to talk to each other in
+more complex topology scenarios.
+The the default value is no.
 .IP "timeout <value>"
 Controls how long
 .B ndppd

src/iface.cc

@@ -71,7 +71,7 @@ iface::~iface()
     _map_dirty = true;
 }
 
-ptr<iface> iface::open_pfd(const std::string& name)
+ptr<iface> iface::open_pfd(const std::string& name, bool promiscuous)
 {
     int fd = 0;
 
@@ -118,6 +118,27 @@ ptr<iface> iface::open_pfd(const std::string& name)
         logger::error() << "Failed to bind to interface '" << name << "'";
         return ptr<iface>();
     }
+    
+    // Switch on promiscuous mode (if instructed)
+    if (promiscuous == true)
+    {
+        struct ifreq ifr;
+        memset(&ifr, 0, sizeof(ifr));
+        strncpy(ifr.ifr_name, name.c_str(), IFNAMSIZ);
+        if (ioctl(fd, SIOCGIFFLAGS, &ifr) < 0) {
+            close(fd);
+            logger::error() << "Failed invoking ioctl(SIOCGIFFLAGS) while setting promiscuous mode on interface '" << name << "'";
+            return ptr<iface>();
+        }
+        if (!(ifr.ifr_flags & IFF_PROMISC)) {
+            ifr.ifr_flags |= IFF_PROMISC;
+            if (ioctl(fd, SIOCSIFFLAGS, &ifr) < 0) {
+                close(fd);
+                logger::error() << "Failed invoking ioctl(SIOCSIFFLAGS) while setting promiscuous mode on interface '" << name << "'";
+                return ptr<iface>();
+            }
+        }
+    }
 
     // Switch to non-blocking mode.
 

src/iface.h

@@ -38,7 +38,7 @@ public:
 
     static ptr<iface> open_ifd(const std::string& name);
 
-    static ptr<iface> open_pfd(const std::string& name);
+    static ptr<iface> open_pfd(const std::string& name, bool promiscuous);
 
     static int poll_all();
 

src/ndppd.cc

@@ -148,8 +148,14 @@ static bool configure(ptr<conf>& cf)
         if (pr_cf->empty()) {
             return false;
         }
+        
+        bool promiscuous = false;
+        if (!(x_cf = pr_cf->find("promiscuous")))
+            promiscuous = false;
+        else
+            promiscuous = *x_cf;
 
-        ptr<proxy> pr = proxy::open(*pr_cf);
+        ptr<proxy> pr = proxy::open(*pr_cf, promiscuous);
         if (!pr || pr.is_null() == true) {
             return false;
         }

src/proxy.cc

@@ -30,15 +30,16 @@ NDPPD_NS_BEGIN
 std::list<ptr<proxy> > proxy::_list;
 
 proxy::proxy() :
-    _router(true), _ttl(30000), _deadtime(3000), _timeout(500), _autowire(false)
+    _router(true), _ttl(30000), _deadtime(3000), _timeout(500), _autowire(false), _promiscuous(false)
 {
 }
 
-ptr<proxy> proxy::create(const ptr<iface>& ifa)
+ptr<proxy> proxy::create(const ptr<iface>& ifa, bool promiscuous)
 {
     ptr<proxy> pr(new proxy());
     pr->_ptr = pr;
     pr->_ifa = ifa;
+    pr->_promiscuous = promiscuous;
 
     _list.push_back(pr);
 
@@ -49,15 +50,15 @@ ptr<proxy> proxy::create(const ptr<iface>& ifa)
     return pr;
 }
 
-ptr<proxy> proxy::open(const std::string& ifname)
+ptr<proxy> proxy::open(const std::string& ifname, bool promiscuous)
 {
-    ptr<iface> ifa = iface::open_pfd(ifname);
+    ptr<iface> ifa = iface::open_pfd(ifname, promiscuous);
 
     if (!ifa) {
         return ptr<proxy>();
     }
 
-    return create(ifa);
+    return create(ifa, promiscuous);
 }
 
 void proxy::handle_solicit(const address& saddr, const address& daddr,
@@ -170,6 +171,11 @@ const ptr<iface>& proxy::ifa() const
     return _ifa;
 }
 
+bool proxy::promiscuous() const
+{
+    return _promiscuous;
+}
+
 bool proxy::router() const
 {
     return _router;

src/proxy.h

@@ -30,9 +30,9 @@ class rule;
 
 class proxy {
 public:
-    static ptr<proxy> create(const ptr<iface>& ifa);
+    static ptr<proxy> create(const ptr<iface>& ifa, bool promiscuous);
 
-    static ptr<proxy> open(const std::string& ifn);
+    static ptr<proxy> open(const std::string& ifn, bool promiscuous);
 
     void handle_solicit(const address& saddr, const address& daddr,
         const address& taddr);
@@ -44,6 +44,8 @@ public:
     ptr<rule> add_rule(const address& addr, bool aut = false);
 
     const ptr<iface>& ifa() const;
+    
+    bool promiscuous() const;
 
     bool router() const;
 
@@ -75,6 +77,8 @@ private:
     std::list<ptr<rule> > _rules;
 
     std::list<ptr<session> > _sessions;
+    
+    bool _promiscuous;
 
     bool _router;