[GNUnet-SVN] r13582 - gnunet/src/vpn

[gnunet]

Author: nevans
Date: 2010-11-06 12:13:31 +0100 (Sat, 06 Nov 2010)
New Revision: 13582

Modified:
   gnunet/src/vpn/gnunet-service-dns.c
Log:
scheduler removal mishap (fix)

Modified: gnunet/src/vpn/gnunet-service-dns.c
===================================================================
--- gnunet/src/vpn/gnunet-service-dns.c 2010-11-05 23:21:26 UTC (rev 13581)
+++ gnunet/src/vpn/gnunet-service-dns.c 2010-11-06 11:13:31 UTC (rev 13582)
@@ -39,7 +39,6 @@
 #include "gnunet_crypto_lib.h"
 #include "gnunet_signatures.h"
 
-
 /**
  * The UDP-Socket through which DNS-Resolves will be sent if they are not to be
  * sent through gnunet. The port of this socket will not be hijacked.
@@ -103,17 +102,17 @@
  * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
  */
 static void
-hijack(unsigned short port) {
+hijack(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
     char port_s[6];
 
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", port);
-    snprintf(port_s, 6, "%d", port);
-    GNUNET_OS_start_process(NULL,
-                           NULL,
-                           "gnunet-helper-hijack-dns",
-                           "gnunet-hijack-dns",
-                           port_s,
-                           NULL);
+    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
+    snprintf(port_s, 6, "%d", dnsoutport);
+    GNUNET_OS_process_close (GNUNET_OS_start_process(NULL,
+                                                    NULL,
+                                                    "gnunet-helper-hijack-dns",
+                                                    "gnunet-hijack-dns",
+                                                    port_s,
+                                                    NULL));
 }
 
 /**
@@ -162,6 +161,81 @@
     return len;
 }
 
+static void
+send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
+    struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
+
+    unsigned short id = pdns->s.id;
+
+    if (query_states[id].valid != GNUNET_YES) return;
+    query_states[id].valid = GNUNET_NO;
+
+    GNUNET_assert(query_states[id].namelen == 74);
+
+    size_t len = sizeof(struct answer_packet) - 1 \
+                + sizeof(struct dns_static) \
+                + 74 /* this is the length of a reverse ipv6-lookup */ \
+                + sizeof(struct dns_query_line) \
+                + 2 /* To hold the pointer (as defined in RFC1035) to the name 
*/ \
+                + sizeof(struct dns_record_line) - 1 \
+                - 2 /* We do not know the lenght of the answer yet*/ \
+                - 2 /* No idea why... */ ;
+
+    struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct 
answer_packet_list*));
+    memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
+
+    answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
+    answer->pkt.hdr.size = htons(len);
+    answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
+
+    answer->pkt.from = query_states[id].remote_ip;
+
+    answer->pkt.to = query_states[id].local_ip;
+    answer->pkt.dst_port = query_states[id].local_port;
+
+    struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
+
+    dpkt->s.id = id;
+    dpkt->s.aa = 1;
+    dpkt->s.qr = 1;
+    dpkt->s.ra = 1;
+    dpkt->s.qdcount = htons(1);
+    dpkt->s.ancount = htons(1);
+
+    memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
+    GNUNET_free(query_states[id].name);
+
+    struct dns_query_line* dque = (struct 
dns_query_line*)(dpkt->data+(query_states[id].namelen));
+    dque->type = htons(12); /* PTR */
+    dque->class = htons(1); /* IN */
+
+    char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct 
dns_query_line));
+    memcpy(anname, (char[]){0xc0, 0x0c}, 2);
+
+    struct dns_record_line *drec_data = (struct 
dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct 
dns_query_line)+2);
+    drec_data->type = htons(12); /* AAAA */
+    drec_data->class = htons(1); /* IN */
+    drec_data->ttl = htonl(3600); /* FIXME: read from block */
+
+    /* Calculate at which offset in the packet the length of the name and the
+     * name, it is filled in by the daemon-vpn */
+    answer->pkt.addroffset = htons((unsigned short)((unsigned 
long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
+
+    GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
+
+    GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
+                                       len,
+                                       GNUNET_TIME_UNIT_FOREVER_REL,
+                                       &send_answer,
+                                       query_states[id].client);
+
+    /*
+     * build
+     * complete dns-packet with empty name in the answer
+     * provide offsett of the name
+     */
+}
+
 /**
  * Receive a block from the dht.
  */
@@ -236,7 +310,6 @@
     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
     GNUNET_free(query_states[id].name);
 
-
     struct dns_query_line* dque = (struct 
dns_query_line*)(dpkt->data+(query_states[id].namelen));
     dque->type = htons(28); /* AAAA */
     dque->class = htons(1); /* IN */
@@ -273,7 +346,9 @@
         struct GNUNET_SERVER_Client *client,
         const struct GNUNET_MessageHeader *message) {
     unhijack(dnsoutport);
-    hijack(dnsoutport);
+    GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
+
+    GNUNET_SERVER_receive_done(client, GNUNET_OK);
 }
 
 /**
@@ -296,6 +371,7 @@
     query_states[dns->s.id].name = 
GNUNET_malloc(query_states[dns->s.id].namelen);
     memcpy(query_states[dns->s.id].name, dns->data, 
query_states[dns->s.id].namelen);
 
+    /* The query is for a .gnunet-address */
     if (pdns->queries[0]->namelen > 9 &&
        0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), 
".gnunet.", 9))
       {
@@ -323,6 +399,18 @@
                                           receive_dht,
                                           cls);
 
+       goto outfree;
+      }
+
+    /* 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))
+      {
+       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
+
+       GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
+
        goto out;
       }
 
@@ -339,9 +427,10 @@
                                 (struct sockaddr*) &dest,
                                 sizeof dest);
 
-out:
+outfree:
     free_parsed_dns_packet(pdns);
     pdns = NULL;
+out:
     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 }
 
@@ -479,6 +568,7 @@
 
 /**
  * @param cls closure
+ * @param sched scheduler to use
  * @param server the initialized server
  * @param cfg configuration to use
  */
@@ -527,8 +617,6 @@
 
   dnsoutport = htons(addr.sin_port);
 
-  hijack(htons(addr.sin_port));
-
   GNUNET_SCHEDULER_add_now (publish_name, NULL);
 
   GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL, dnsout, 
&read_response, NULL);