From: Philipp Tölke <toelke@in.tum.de>
Date: Tue, 2 Nov 2010 21:40:05 +0000 (+0000)
Subject: Fixes and documentation
X-Git-Tag: initial-import-from-subversion-38251~19866
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=736b5e9964c384c85c3e00a128cefb34b15d9f11;p=oweals%2Fgnunet.git

Fixes and documentation
---

diff --git a/src/vpn/gnunet-dns-parser.c b/src/vpn/gnunet-dns-parser.c
index 7b81f6da4..e26638141 100644
--- a/src/vpn/gnunet-dns-parser.c
+++ b/src/vpn/gnunet-dns-parser.c
@@ -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;
-
-	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;
+/**
+ * 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;
+
+    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;
-
-		_idx = parse_dns_name(name, data, idx);
-		dst[i]->namelen = _idx - idx;
-		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;
+/**
+ * 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;
+
+	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);
-
-	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*));
-
-	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. */
-
-		_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]->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;
+/**
+ * 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);
+
+    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 */
+
+    /* 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;
+
+	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;
 }/*}}}*/
+
+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);
+}
diff --git a/src/vpn/gnunet-dns-parser.h b/src/vpn/gnunet-dns-parser.h
index 1ee82e7a3..ea1a5765c 100644
--- a/src/vpn/gnunet-dns-parser.h
+++ b/src/vpn/gnunet-dns-parser.h
@@ -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
diff --git a/src/vpn/gnunet-service-dns-p.h b/src/vpn/gnunet-service-dns-p.h
index 01605dcf2..5b61ba653 100644
--- a/src/vpn/gnunet-service-dns-p.h
+++ b/src/vpn/gnunet-service-dns-p.h
@@ -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 @@ enum GNUNET_DNS_ANSWER_Subtype {
     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 @@ struct answer_packet {
     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];
diff --git a/src/vpn/gnunet-service-dns.c b/src/vpn/gnunet-service-dns.c
index ee2549d17..6c95c7789 100644
--- a/src/vpn/gnunet-service-dns.c
+++ b/src/vpn/gnunet-service-dns.c
@@ -331,7 +331,6 @@ receive_query(void *cls,
       }
 
     /* The query should be sent to the network */
-    GNUNET_free(pdns);
 
     struct sockaddr_in dest;
     memset(&dest, 0, sizeof dest);
@@ -345,6 +344,8 @@ receive_query(void *cls,
 				 sizeof dest);
 
 out:
+    free_parsed_dns_packet(pdns);
+    pdns = NULL;
     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 }
 
@@ -459,7 +460,7 @@ publish_name (void *cls,
 	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",