From 1f50dc5b5a56e8493183d360e6c91641e66c1665 Mon Sep 17 00:00:00 2001
From: John Sharratt <John@TheAlien.(none)>
Date: Mon, 3 Jul 2017 20:12:36 +0200
Subject: [PATCH] NDP proxy will now respond to Solicitation requests to
 gateway addresses that it holds on secondary interfaces

---
 src/address.cc | 22 +++++++++++++++++-----
 src/address.h  |  6 ++++--
 src/proxy.cc   | 50 ++++++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 65 insertions(+), 13 deletions(-)

diff --git a/src/address.cc b/src/address.cc
index 49f082e..f0298d7 100644
--- a/src/address.cc
+++ b/src/address.cc
@@ -318,9 +318,14 @@ void address::add(const address& addr, const std::string& ifname)
     _addresses.push_back(rt);
 }
 
-std::list<ptr<route> > address::addresses()
+std::list<ptr<route> >::iterator address::addresses_begin()
 {
-    return _addresses;
+    return _addresses.begin();
+}
+
+std::list<ptr<route> >::iterator address::addresses_end()
+{
+    return _addresses.end();
 }
 
 void address::load(const std::string& path)
@@ -342,24 +347,31 @@ void address::load(const std::string& path)
             ifs.getline(buf, sizeof(buf));
 
             if (ifs.gcount() < 53) {
+                logger::debug() << "skipping entry (size=" << ifs.gcount() << ")";
                 continue;
             }
 
             address addr;
 
-            if (route::hexdec(buf, (unsigned char* )&addr.addr(), 32) != 32) {
-                // TODO: Warn here?
+            if (route::hexdec(buf, (unsigned char* )&addr.addr(), 16) != 16) {
+                logger::warning() << "failed to load address (" << buf << ")";
                 continue;
             }
             
             addr.prefix(128);
+            
+            std::string iface = route::token(buf + 45);
 
-            address::add(addr, route::token(buf + 45));
+            address::add(addr, iface);
+            
+            logger::debug() << "found local addr=" << addr << ", iface=" << iface;
         }
     } catch (std::ifstream::failure e) {
         logger::warning() << "Failed to parse IPv6 address data from '" << path << "'";
         logger::error() << e.what();
     }
+    
+    logger::debug() << "completed IP addresses load";
 }
 
 void address::update(int elapsed_time)
diff --git a/src/address.h b/src/address.h
index 9b14fc5..90b1a03 100644
--- a/src/address.h
+++ b/src/address.h
@@ -70,11 +70,13 @@ public:
 
     operator std::string() const;
     
-    static std::list<ptr<route> > addresses();
-    
     static void add(const address& addr, const std::string& ifname);
     
     static void load(const std::string& path);
+    
+    static std::list<ptr<route> >::iterator addresses_begin();
+    
+    static std::list<ptr<route> >::iterator addresses_end();
 
 private:
     static int _ttl;
diff --git a/src/proxy.cc b/src/proxy.cc
index 5e32b2f..226b581 100644
--- a/src/proxy.cc
+++ b/src/proxy.cc
@@ -75,11 +75,34 @@ ptr<session> proxy::find_or_create_session(const address& saddr, const address&
             return (*sit);
     }
     
-    // Since we couldn't find a session that matched, we'll try to find
-    // a matching rule instead, and then set up a new session.
+    // Check if there is an address for this specific interface it was received
+    // on (if so then immediately return a notice)
     
     ptr<session> se;
     
+    if (receiver) {
+        for (std::list<ptr<route> >::iterator ad = address::addresses_begin();
+                ad != address::addresses_end(); ad++)
+        {
+            if ((*ad)->addr() == taddr && (*ad)->ifname() == receiver->name())
+            {
+                se = session::create(_ptr, saddr, daddr, taddr, _autowire);
+                if (se) {
+                    se->add_iface(receiver);
+                    _sessions.push_back(se);
+                    
+                    logger::debug() << "proxy::handle_advert() found local taddr=" << taddr;
+                    se->handle_advert(receiver);
+                    
+                    return se;
+                }
+            }
+        }
+    }
+    
+    // Since we couldn't find a session that matched, we'll try to find
+    // a matching rule instead, and then set up a new session.
+    
     for (std::list<ptr<rule> >::iterator it = _rules.begin();
             it != _rules.end(); it++) {
         ptr<rule> ru = *it;
@@ -116,14 +139,29 @@ ptr<session> proxy::find_or_create_session(const address& saddr, const address&
                 se->handle_advert();
                 return se;
             } else {
-                se->add_iface((*it)->ifa());
+                
+                ptr<iface> ifa = (*it)->ifa();
+                se->add_iface(ifa);
+                
                 #ifdef WITH_ND_NETLINK
-                if (if_addr_find((*it)->ifa()->name(), &taddr.const_addr())) {
-                    logger::debug() << "Sending NA out " << (*it)->ifa()->name();
+                if (if_addr_find(ifa->name(), &taddr.const_addr())) {
+                    logger::debug() << "Sending NA out " << ifa->name();
                     se->add_iface(_ifa);
                     se->handle_advert();
                 }
                 #endif
+
+                // If a local address exists and it is for the requested interface
+                // then we already have a valid session
+                for (std::list<ptr<route> >::iterator ad = address::addresses_begin();
+                        ad != address::addresses_end(); ad++)
+                {
+                    if ((*ad)->addr() == taddr && (*ad)->ifname() == ifa->name()) {
+                        logger::debug() << "proxy::handle_advert() found local taddr=" << taddr;
+                        se->handle_advert(ifa);
+                        break;
+                    }
+                }
             }
         }
     }
@@ -142,7 +180,7 @@ void proxy::handle_advert(const address& saddr, const address& taddr, const ptr<
         << ", saddr=" << saddr.to_string()
         << ", taddr=" << taddr.to_string();
     
-    ptr<session> se = find_or_create_session(saddr, all_nodes, taddr, receiver);
+    ptr<session> se = find_or_create_session(all_nodes, all_nodes, taddr, receiver);
     if (!se) return;
     
     se->handle_advert(receiver);