3 files changed, 102 insertions, 30 deletions

diff --git a/src/vpn/gnunet-daemon-vpn.c b/src/vpn/gnunet-daemon-vpn.c
index 1213dd9f1..0c3c137fa 100644
--- a/src/vpn/gnunet-daemon-vpn.c
+++ b/src/vpn/gnunet-daemon-vpn.c
@@ -215,10 +215,27 @@ send_udp_to_peer (void *cls,
  * Create a new Address from an answer-packet
  */
 void
-new_ip6addr(char* buf, const GNUNET_HashCode *peer, const GNUNET_HashCode *service_desc) { /* {{{ */
-        memcpy(buf+14, (int[]){htons(0x3412)}, 2);
-        memcpy(buf+8, service_desc, 6);
-        memcpy(buf, peer, 8);
+new_ip6addr(unsigned char* buf, const GNUNET_HashCode *peer, const GNUNET_HashCode *service_desc) { /* {{{ */
+    char* ipv6addr;
+    unsigned long long ipv6prefix;
+    GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
+    GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
+    GNUNET_assert(ipv6prefix < 127);
+    ipv6prefix = (ipv6prefix + 7)/8;
+
+    inet_pton (AF_INET6, ipv6addr, buf);
+    GNUNET_free(ipv6addr);
+
+    int peer_length = 16 - ipv6prefix - 6;
+    if (peer_length <= 0)
+      peer_length = 0;
+
+    int service_length = 16 - ipv6prefix - peer_length;
+    if (service_length <= 0)
+      service_length = 0;
+
+    memcpy(buf+ipv6prefix, service_desc, service_length);
+    memcpy(buf+ipv6prefix+service_length, peer, peer_length);
 }
 /*}}}*/
 
@@ -246,7 +263,16 @@ process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 
         GNUNET_HashCode key;
         memset(&key, 0, sizeof(GNUNET_HashCode));
-        new_ip6addr((char*)&key, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
+
+        unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
+        unsigned char* k = (unsigned char*)&key;
+        new_ip6addr(c, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
+        /*
+         * Copy the newly generated ip-address to the key backwarts (as only the first part is hashed)
+         */
+        unsigned int i;
+        for (i = 0; i < 16; i++)
+            k[15-i] = c[i];
 
         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 
@@ -268,14 +294,6 @@ process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
             GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not store to hashmap\n");
           }
 
-        /*
-         * Copy the newly generated backward ip-address to the packet
-         */
-        char* c = ((char*)pkt)+ntohs(pkt->addroffset);
-        char* k = (char*)&key;
-        unsigned int i;
-        for (i = 0; i < 16; i++)
-            c[15-i] = k[i];
 
         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 
@@ -374,17 +392,16 @@ receive_udp_back (void *cls, struct GNUNET_MESH_Tunnel* tunnel,
 {
   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
   struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
-  char addr[16];
   const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
 
-  new_ip6addr(addr, &other->hashPubKey, desc);
-
   size_t size = sizeof(struct ip6_udp) + ntohs(pkt->len) - 1 - sizeof(struct udp_pkt);
 
   struct ip6_udp* pkt6 = alloca(size);
 
   GNUNET_assert(pkt6 != NULL);
 
+  new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
+
   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs(message->size), ntohs(pkt->len));
 
   pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
@@ -401,10 +418,6 @@ receive_udp_back (void *cls, struct GNUNET_MESH_Tunnel* tunnel,
   pkt6->ip6_hdr.nxthdr = 0x11;
   pkt6->ip6_hdr.hoplmt = 0xff;
 
-  unsigned int i;
-  for (i = 0; i < 16; i++)
-    pkt6->ip6_hdr.sadr[15-i] = addr[i];
-
   {
     char* ipv6addr;
     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
diff --git a/src/vpn/gnunet-helper-hijack-dns.c b/src/vpn/gnunet-helper-hijack-dns.c
index 7a41b27d2..ee7ae1873 100644
--- a/src/vpn/gnunet-helper-hijack-dns.c
+++ b/src/vpn/gnunet-helper-hijack-dns.c
@@ -47,14 +47,17 @@ int fork_and_exec(char* file, char* cmd[]) {
 int main(int argc, char** argv) {
         int delete = 0;
         int port = 0;
-        if (argc < 2) return GNUNET_SYSERR;
+        char* virt_dns;
+        if (argc < 3) return GNUNET_SYSERR;
 
         if (strncmp(argv[1], "-d", 2) == 0) {
                 if (argc < 3) return GNUNET_SYSERR;
                 delete = 1;
                 port = atoi(argv[2]);
+                virt_dns = argv[3];
         } else {
                 port = atoi(argv[1]);
+                virt_dns = argv[2];
         }
 
         if (port == 0) return GNUNET_SYSERR;
@@ -75,7 +78,7 @@ int main(int argc, char** argv) {
         int r;
         if (delete) {
 e4:
-                r = fork_and_exec("/sbin/ip", (char*[]){"ip", "route", "del", "default", "via", "10.10.10.2","table","2", NULL});
+                r = fork_and_exec("/sbin/ip", (char*[]){"ip", "route", "del", "default", "via", virt_dns,"table","2", NULL});
 e3:
                 r = fork_and_exec("/sbin/ip", (char*[]){"ip", "rule", "del", "fwmark", "3", "table","2", NULL});
 e2:
@@ -90,7 +93,7 @@ e1:
                 if (!r) goto e2;
                 r = fork_and_exec("/sbin/ip", (char*[]){"ip", "rule", "add", "fwmark", "3", "table","2", NULL});
                 if (!r) goto e3;
-                r = fork_and_exec("/sbin/ip", (char*[]){"ip", "route", "add", "default", "via", "10.10.10.2","table","2", NULL});
+                r = fork_and_exec("/sbin/ip", (char*[]){"ip", "route", "add", "default", "via", virt_dns, "table","2", NULL});
                 if (!r) goto e4;
         }
         if (r) return GNUNET_YES;
diff --git a/src/vpn/gnunet-service-dns.c b/src/vpn/gnunet-service-dns.c
index b8488d3e1..12a85cdd1 100644
--- a/src/vpn/gnunet-service-dns.c
+++ b/src/vpn/gnunet-service-dns.c
@@ -104,6 +104,13 @@ struct receive_dht_cls {
 static void
 hijack(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
     char port_s[6];
+    char* virt_dns;
+
+    if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "VIRTDNS", &virt_dns))
+      {
+        GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'VIRTDNS' in configuration!\n");
+        exit(1);
+      }
 
     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
     snprintf(port_s, 6, "%d", dnsoutport);
@@ -112,6 +119,7 @@ hijack(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
                                                      "gnunet-helper-hijack-dns",
                                                      "gnunet-hijack-dns",
                                                      port_s,
+                                                     virt_dns,
                                                      NULL));
 }
 
@@ -121,6 +129,13 @@ hijack(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 static void
 unhijack(unsigned short port) {
     char port_s[6];
+    char* virt_dns;
+
+    if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "VIRTDNS", &virt_dns))
+      {
+        GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'VIRTDNS' in configuration!\n");
+        exit(1);
+      }
 
     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
     snprintf(port_s, 6, "%d", port);
@@ -130,6 +145,7 @@ unhijack(unsigned short port) {
                             "gnunet-hijack-dns",
                             "-d",
                             port_s,
+                            virt_dns,
                             NULL);
 }
 
@@ -403,16 +419,56 @@ receive_query(void *cls,
         goto outfree;
       }
 
+    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen);
     /* The query is for a PTR of a previosly resolved virtual IP */
     if (htons(pdns->queries[0]->qtype) == 12 &&
-        pdns->queries[0]->namelen > 19 &&
-        0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 19), ".4.3.2.1.ip6.arpa.", 19))
+        74 == pdns->queries[0]->namelen)
       {
-        GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
-
-        GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
-
-        goto out;
+        char* ipv6addr;
+        char ipv6[16];
+        char ipv6rev[74] = "X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.ip6.arpa.";
+        unsigned int i;
+        unsigned long long ipv6prefix;
+        unsigned int comparelen;
+
+        GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
+        inet_pton (AF_INET6, ipv6addr, ipv6);
+        GNUNET_free(ipv6addr);
+
+        GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
+        GNUNET_assert(ipv6prefix < 127);
+        ipv6prefix = (ipv6prefix + 7)/8;
+
+        for (i = ipv6prefix; i < 16; i++)
+          ipv6[i] = 0;
+
+        for (i = 0; i < 16; i++)
+          {
+            unsigned char c1 = ipv6[i] >> 4;
+            unsigned char c2 = ipv6[i] & 0xf;
+
+            if (c1 <= 9)
+              ipv6rev[62-(4*i)] = c1 + '0';
+            else
+              ipv6rev[62-(4*i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
+
+            if (c2 <= 9)
+              ipv6rev[62-((4*i)+2)] = c2 + '0';
+            else
+              ipv6rev[62-((4*i)+2)] = c2 + 87;
+          }
+        GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
+        comparelen = 10 + 4*ipv6prefix;
+        if(0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - comparelen),
+                        ipv6rev + (74 - comparelen),
+                        comparelen))
+          {
+            GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
+
+            GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
+
+            goto out;
+          }
       }
 
     /* The query should be sent to the network */