[GNUnet-SVN] r13507 - gnunet/src/vpn

[gnunet]

Author: toelke
Date: 2010-11-02 22:40:05 +0100 (Tue, 02 Nov 2010)
New Revision: 13507

Modified:
   gnunet/src/vpn/gnunet-dns-parser.c
   gnunet/src/vpn/gnunet-dns-parser.h
   gnunet/src/vpn/gnunet-service-dns-p.h
   gnunet/src/vpn/gnunet-service-dns.c
Log:
Fixes and documentation

Modified: gnunet/src/vpn/gnunet-dns-parser.c
===================================================================
--- gnunet/src/vpn/gnunet-dns-parser.c  2010-11-02 21:40:03 UTC (rev 13506)
+++ gnunet/src/vpn/gnunet-dns-parser.c  2010-11-02 21:40:05 UTC (rev 13507)
@@ -2,92 +2,160 @@
 #include "gnunet-dns-parser.h"
 #include "gnunet-vpn-packet.h"
 
-unsigned int parse_dns_name(char* d, const unsigned char* src, unsigned short 
idx) {/*{{{*/
-       char* dest = d;
+/**
+ * Parse a name from DNS to a normal .-delimited, 0-terminated string.
+ *
+ * @param d The destination of the name. Should have at least 255 bytes 
allocated.
+ * @param src The DNS-Packet
+ * @param idx The offset inside the Packet from which on the name should be 
read
+ * @returns The offset of the first unparsed byte (the byte right behind the 
name)
+ */
+static unsigned int
+parse_dns_name(char* d, const unsigned char* src, unsigned short idx) {/*{{{*/
+    char* dest = d;
 
-       int len = src[idx++];
-       while (len != 0) {
-               if (len & 0xC0) { /* Compressed name, offset in this and the 
next octet */
-                       unsigned short offset = ((len & 0x3F) << 8) | 
src[idx++];
-                       parse_dns_name(dest, src, offset - 12); /* 12 for the 
Header of the DNS-Packet, idx starts at 0 which is 12 bytes from the start of 
the packet */
-                       return idx;
-               }
-               memcpy(dest, src+idx, len);
-               idx += len;
-               dest += len;
-               *dest = '.';
-               dest++;
-               len = src[idx++];
-       };
-       *dest = 0;
+    int len = src[idx++];
+    while (len != 0)
+      {
+       if (len & 0xC0)
+         { /* Compressed name, offset in this and the next octet */
+           unsigned short offset = ((len & 0x3F) << 8) | src[idx++];
+           parse_dns_name(dest, src, offset - 12); /* 12 for the Header of the 
DNS-Packet, idx starts at 0 which is 12 bytes from the start of the packet */
+           return idx;
+         }
+       memcpy(dest, src+idx, len);
+       idx += len;
+       dest += len;
+       *dest = '.';
+       dest++;
+       len = src[idx++];
+      };
+    *dest = 0;
 
-       return idx;
+    return idx;
 }
 /*}}}*/
 
-unsigned short parse_dns_record(unsigned char* data, struct dns_record** dst, 
unsigned short count, unsigned short idx) {/*{{{*/
-       int i;
-       unsigned short _idx;
-       for (i = 0; i < count; i++) {
-               dst[i] = GNUNET_malloc(sizeof(struct dns_record));
-               dst[i]->name = alloca(255); // see RFC1035
-               char* name = dst[i]->name;
+/**
+ * Parse a complete DNS-Record from raw DNS-data to a struct dns_record
+ *
+ * @param data The DNS-data
+ * @param dst Pointer to count pointers; individual pointers will be allocated
+ * @param count Number of records to parse
+ * @param idx The offset inside the Packet from which on the name should be 
read
+ * @returns The offset of the first unparsed byte (the byte right behind the 
last record)
+ */
+static unsigned short
+parse_dns_record(unsigned char* data, /*{{{*/
+                struct dns_record** dst,
+                unsigned short count,
+                unsigned short idx) {
+    int i;
+    unsigned short _idx;
+    for (i = 0; i < count; i++) {
+       dst[i] = GNUNET_malloc(sizeof(struct dns_record));
+       dst[i]->name = alloca(255); // see RFC1035, no name can be longer than 
this.
+       char* name = dst[i]->name;
 
-               _idx = parse_dns_name(name, data, idx);
-               dst[i]->namelen = _idx - idx;
-               idx = _idx;
+       _idx = parse_dns_name(name, data, idx);
+       dst[i]->namelen = _idx - idx;
 
-               dst[i]->type = *((unsigned short*)(data+idx));
-               idx += 2;
-               dst[i]->class = *((unsigned short*)(data+idx));
-               idx += 2;
-               dst[i]->ttl = *((unsigned int*)(data+idx));
-               idx += 4;
-               dst[i]->data_len = *((unsigned short*)(data+idx));
-               idx += 2;
-               dst[i]->data = GNUNET_malloc(ntohs(dst[i]->data_len));
-               memcpy(dst[i]->data, data+idx, ntohs(dst[i]->data_len));
-               idx += ntohs(dst[i]->data_len);
-       }
-       return idx;
+       dst[i]->name = GNUNET_malloc(dst[i]->namelen);
+       memcpy(dst[i]->name, name, dst[i]->namelen);
+
+       idx = _idx;
+
+       dst[i]->type = *((unsigned short*)(data+idx));
+       idx += 2;
+       dst[i]->class = *((unsigned short*)(data+idx));
+       idx += 2;
+       dst[i]->ttl = *((unsigned int*)(data+idx));
+       idx += 4;
+       dst[i]->data_len = *((unsigned short*)(data+idx));
+       idx += 2;
+       dst[i]->data = GNUNET_malloc(ntohs(dst[i]->data_len));
+       memcpy(dst[i]->data, data+idx, ntohs(dst[i]->data_len));
+       idx += ntohs(dst[i]->data_len);
+    }
+    return idx;
 }/*}}}*/
 
-struct dns_pkt_parsed* parse_dns_packet(struct dns_pkt* pkt) {/*{{{*/
-       struct dns_pkt_parsed* ppkt = GNUNET_malloc(sizeof(struct 
dns_pkt_parsed));
-       memcpy(&ppkt->s, &pkt->s, sizeof pkt->s);
+/**
+ * Parse a raw DNS-Packet into an usable struct
+ */
+struct dns_pkt_parsed*
+parse_dns_packet(struct dns_pkt* pkt) {/*{{{*/
+    struct dns_pkt_parsed* ppkt = GNUNET_malloc(sizeof(struct dns_pkt_parsed));
+    memcpy(&ppkt->s, &pkt->s, sizeof pkt->s);
 
-       unsigned short qdcount = ntohs(ppkt->s.qdcount);
-       unsigned short ancount = ntohs(ppkt->s.ancount);
-       unsigned short nscount = ntohs(ppkt->s.nscount);
-       unsigned short arcount = ntohs(ppkt->s.arcount);
+    unsigned short qdcount = ntohs(ppkt->s.qdcount);
+    unsigned short ancount = ntohs(ppkt->s.ancount);
+    unsigned short nscount = ntohs(ppkt->s.nscount);
+    unsigned short arcount = ntohs(ppkt->s.arcount);
 
-       ppkt->queries = GNUNET_malloc(qdcount*sizeof(struct dns_query*));
-       ppkt->answers = GNUNET_malloc(ancount*sizeof(struct dns_record*));
-       ppkt->nameservers = GNUNET_malloc(nscount*sizeof(struct dns_record*));
-       ppkt->additional = GNUNET_malloc(arcount*sizeof(struct dns_record*));
+    ppkt->queries = GNUNET_malloc(qdcount*sizeof(struct dns_query*));
+    ppkt->answers = GNUNET_malloc(ancount*sizeof(struct dns_record*));
+    ppkt->nameservers = GNUNET_malloc(nscount*sizeof(struct dns_record*));
+    ppkt->additional = GNUNET_malloc(arcount*sizeof(struct dns_record*));
 
-       unsigned short idx = 0, _idx; /* This keeps track how far we have 
parsed the data */
+    unsigned short idx = 0, _idx; /* This keeps track how far we have parsed 
the data */
 
-       int i;
-       for (i = 0; i < qdcount; i++) { /*{{{*/
-               ppkt->queries[i] = GNUNET_malloc(sizeof(struct dns_query));
-               char* name = alloca(255); /* see RFC1035, it can't be more than 
this. */
+    /* Parse the Query */
+    int i;
+    for (i = 0; i < qdcount; i++)
+      { /*{{{*/
+       ppkt->queries[i] = GNUNET_malloc(sizeof(struct dns_query));
+       char* name = alloca(255); /* see RFC1035, it can't be more than this. */
 
-               _idx = parse_dns_name(name, pkt->data, idx);
-               ppkt->queries[i]->namelen = _idx - idx;
-               idx = _idx;
+       _idx = parse_dns_name(name, pkt->data, idx);
+       ppkt->queries[i]->namelen = _idx - idx;
+       idx = _idx;
 
-               ppkt->queries[i]->name = 
GNUNET_malloc(ppkt->queries[i]->namelen + 1);
-               memcpy(ppkt->queries[i]->name, name, ppkt->queries[i]->namelen 
+ 1);
+       ppkt->queries[i]->name = GNUNET_malloc(ppkt->queries[i]->namelen);
+       memcpy(ppkt->queries[i]->name, name, ppkt->queries[i]->namelen);
 
-               ppkt->queries[i]->qtype = *((unsigned short*)(pkt->data+idx));
-               idx += 2;
-               ppkt->queries[i]->qclass = *((unsigned short*)(pkt->data+idx));
-               idx += 2;
-       }
-       /*}}}*/
-       idx = parse_dns_record(pkt->data, ppkt->answers, ancount, idx);
-       idx = parse_dns_record(pkt->data, ppkt->nameservers, nscount, idx);
-       idx = parse_dns_record(pkt->data, ppkt->additional, arcount, idx);
-       return ppkt;
+       ppkt->queries[i]->qtype = *((unsigned short*)(pkt->data+idx));
+       idx += 2;
+       ppkt->queries[i]->qclass = *((unsigned short*)(pkt->data+idx));
+       idx += 2;
+    }
+    /*}}}*/
+    idx = parse_dns_record(pkt->data, ppkt->answers, ancount, idx);
+    idx = parse_dns_record(pkt->data, ppkt->nameservers, nscount, idx);
+    idx = parse_dns_record(pkt->data, ppkt->additional, arcount, idx);
+    return ppkt;
 }/*}}}*/
+
+void
+free_parsed_dns_packet(struct dns_pkt_parsed* ppkt) {
+    unsigned short qdcount = ntohs(ppkt->s.qdcount);
+    unsigned short ancount = ntohs(ppkt->s.ancount);
+    unsigned short nscount = ntohs(ppkt->s.nscount);
+    unsigned short arcount = ntohs(ppkt->s.arcount);
+
+    int i;
+    for (i = 0; i < qdcount; i++) {
+       GNUNET_free(ppkt->queries[i]->name);
+       GNUNET_free(ppkt->queries[i]);
+    }
+    GNUNET_free(ppkt->queries);
+    for (i = 0; i < ancount; i++) {
+       GNUNET_free(ppkt->answers[i]->name);
+       GNUNET_free(ppkt->answers[i]->data);
+       GNUNET_free(ppkt->answers[i]);
+    }
+    GNUNET_free(ppkt->answers);
+    for (i = 0; i < nscount; i++) {
+       GNUNET_free(ppkt->nameservers[i]->name);
+       GNUNET_free(ppkt->nameservers[i]->data);
+       GNUNET_free(ppkt->nameservers[i]);
+    }
+    GNUNET_free(ppkt->nameservers);
+    for (i = 0; i < arcount; i++) {
+       GNUNET_free(ppkt->additional[i]->name);
+       GNUNET_free(ppkt->additional[i]->data);
+       GNUNET_free(ppkt->additional[i]);
+    }
+    GNUNET_free(ppkt->additional);
+    GNUNET_free(ppkt);
+}

Modified: gnunet/src/vpn/gnunet-dns-parser.h
===================================================================
--- gnunet/src/vpn/gnunet-dns-parser.h  2010-11-02 21:40:03 UTC (rev 13506)
+++ gnunet/src/vpn/gnunet-dns-parser.h  2010-11-02 21:40:05 UTC (rev 13507)
@@ -6,4 +6,6 @@
 
 struct dns_pkt_parsed* parse_dns_packet(struct dns_pkt* pkt);
 
+void free_parsed_dns_packet(struct dns_pkt_parsed* ppkt);
+
 #endif

Modified: gnunet/src/vpn/gnunet-service-dns-p.h
===================================================================
--- gnunet/src/vpn/gnunet-service-dns-p.h       2010-11-02 21:40:03 UTC (rev 
13506)
+++ gnunet/src/vpn/gnunet-service-dns-p.h       2010-11-02 21:40:05 UTC (rev 
13507)
@@ -5,9 +5,18 @@
 
 struct query_packet {
        struct GNUNET_MessageHeader hdr;
-       
-       unsigned orig_to:32 GNUNET_PACKED; /* The IP-Address, this query was 
originally sent to */
+
+       /**
+        * The IP-Address this query was originally sent to
+        */
+       unsigned orig_to:32 GNUNET_PACKED;
+       /**
+        * The IP-Address this query was originally sent from
+        */
        unsigned orig_from:32 GNUNET_PACKED;
+       /**
+        * The UDP-Portthis query was originally sent from
+        */
        unsigned src_port:16 GNUNET_PACKED;
 
        unsigned char data[1]; /* The DNS-Packet */
@@ -26,7 +35,8 @@
     GNUNET_DNS_ANSWER_TYPE_IP,
 
     /**
-     * Answers of this type contain an struct GNUNET_DNS_Record
+     * Answers of this type contain an incomplete dns-packet. The IP-Address
+     * is all 0s. The addroffset points to it.
      */
     GNUNET_DNS_ANSWER_TYPE_SERVICE
 };
@@ -39,11 +49,14 @@
     unsigned to:32 GNUNET_PACKED;
     unsigned dst_port:16 GNUNET_PACKED;
 
+    /* Only sensible when subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE */
     GNUNET_HashCode peer;
     GNUNET_HashCode service_descriptor;
     uint64_t ports;
     uint32_t service_type;
 
+    /* The offsett in octets from the beginning of the struct to the field
+     * in data where the IP-Address has to go. */
     unsigned addroffset:16 GNUNET_PACKED;
 
     unsigned char data[1];

Modified: gnunet/src/vpn/gnunet-service-dns.c
===================================================================
--- gnunet/src/vpn/gnunet-service-dns.c 2010-11-02 21:40:03 UTC (rev 13506)
+++ gnunet/src/vpn/gnunet-service-dns.c 2010-11-02 21:40:05 UTC (rev 13507)
@@ -331,7 +331,6 @@
       }
 
     /* The query should be sent to the network */
-    GNUNET_free(pdns);
 
     struct sockaddr_in dest;
     memset(&dest, 0, sizeof dest);
@@ -345,6 +344,8 @@
                                 sizeof dest);
 
 out:
+    free_parsed_dns_packet(pdns);
+    pdns = NULL;
     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 }
 
@@ -459,7 +460,7 @@
        GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
        return;
       }
-    GNUNET_free(my_private_key);
+    GNUNET_CRYPTO_rsa_key_free(my_private_key);
 
     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
               "Putting with key %08x\n",