commit 38be3ab6333e09e5689b4626bf9caa93bd1bbfba
parent 8babf5f841c8d364a0ab271e395f7e9a0e9b2632
Author: Christian Grothoff <christian@grothoff.org>
Date: Sat, 24 Aug 2013 10:05:43 +0000
-expose API for parsing individual DNS record types
Diffstat:
3 files changed, 410 insertions(+), 195 deletions(-)
diff --git a/src/dns/dnsparser.c b/src/dns/dnsparser.c
@@ -102,6 +102,87 @@ GNUNET_DNSPARSER_check_name (const char *name)
/**
+ * Free SOA information record.
+ *
+ * @param soa record to free
+ */
+static void
+free_soa (struct GNUNET_DNSPARSER_SoaRecord *soa)
+{
+ if (NULL == soa)
+ return;
+ GNUNET_free_non_null (soa->mname);
+ GNUNET_free_non_null (soa->rname);
+ GNUNET_free (soa);
+}
+
+
+/**
+ * Free SRV information record.
+ *
+ * @param srv record to free
+ */
+static void
+free_srv (struct GNUNET_DNSPARSER_SrvRecord *srv)
+{
+ if (NULL == srv)
+ return;
+ GNUNET_free_non_null (srv->target);
+ GNUNET_free_non_null (srv->domain_name);
+ GNUNET_free_non_null (srv->proto);
+ GNUNET_free_non_null (srv->service);
+ GNUNET_free (srv);
+}
+
+
+/**
+ * Free MX information record.
+ *
+ * @param mx record to free
+ */
+static void
+free_mx (struct GNUNET_DNSPARSER_MxRecord *mx)
+{
+ if (NULL == mx)
+ return;
+ GNUNET_free_non_null (mx->mxhost);
+ GNUNET_free (mx);
+}
+
+
+/**
+ * Free the given DNS record.
+ *
+ * @param r record to free
+ */
+static void
+free_record (struct GNUNET_DNSPARSER_Record *r)
+{
+ GNUNET_free_non_null (r->name);
+ switch (r->type)
+ {
+ case GNUNET_DNSPARSER_TYPE_MX:
+ free_mx (r->data.mx);
+ break;
+ case GNUNET_DNSPARSER_TYPE_SOA:
+ free_soa (r->data.soa);
+ break;
+ case GNUNET_DNSPARSER_TYPE_SRV:
+ free_srv (r->data.srv);
+ break;
+ case GNUNET_DNSPARSER_TYPE_NS:
+ case GNUNET_DNSPARSER_TYPE_CNAME:
+ case GNUNET_DNSPARSER_TYPE_PTR:
+ GNUNET_free_non_null (r->data.hostname);
+ break;
+ default:
+ GNUNET_free_non_null (r->data.raw.data);
+ break;
+ }
+}
+
+
+/**
* Parse name inside of a DNS query or record.
*
* @param udp_payload entire UDP payload
@@ -219,6 +300,24 @@ parse_name (const char *udp_payload,
/**
+ * Parse name inside of a DNS query or record.
+ *
+ * @param udp_payload entire UDP payload
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the name to parse in the udp_payload (to be
+ * incremented by the size of the name)
+ * @return name as 0-terminated C string on success, NULL if the payload is malformed
+ */
+char *
+GNUNET_DNSPARSER_parse_name (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off)
+{
+ return parse_name (udp_payload, udp_payload_length, off, 0);
+}
+
+
+/**
* Parse a DNS query entry.
*
* @param udp_payload entire UDP payload
@@ -228,18 +327,18 @@ parse_name (const char *udp_payload,
* @param q where to write the query information
* @return #GNUNET_OK on success, #GNUNET_SYSERR if the query is malformed
*/
-static int
-parse_query (const char *udp_payload,
- size_t udp_payload_length,
- size_t *off,
- struct GNUNET_DNSPARSER_Query *q)
+int
+GNUNET_DNSPARSER_parse_query (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off,
+ struct GNUNET_DNSPARSER_Query *q)
{
char *name;
struct GNUNET_TUN_DnsQueryLine ql;
- name = parse_name (udp_payload,
- udp_payload_length,
- off, 0);
+ name = GNUNET_DNSPARSER_parse_name (udp_payload,
+ udp_payload_length,
+ off);
if (NULL == name)
return GNUNET_SYSERR;
q->name = name;
@@ -254,6 +353,168 @@ parse_query (const char *udp_payload,
/**
+ * Parse a DNS SOA record.
+ *
+ * @param udp_payload reference to UDP packet
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the query to parse in the SOA record (to be
+ * incremented by the size of the record), unchanged on error
+ * @return the parsed SOA record, NULL on error
+ */
+struct GNUNET_DNSPARSER_SoaRecord *
+GNUNET_DNSPARSER_parse_soa (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off)
+{
+ struct GNUNET_DNSPARSER_SoaRecord *soa;
+ struct GNUNET_TUN_DnsSoaRecord soa_bin;
+ size_t old_off;
+
+ old_off = *off;
+ soa = GNUNET_new (struct GNUNET_DNSPARSER_SoaRecord);
+ soa->mname = GNUNET_DNSPARSER_parse_name (udp_payload,
+ udp_payload_length,
+ off);
+ soa->rname = GNUNET_DNSPARSER_parse_name (udp_payload,
+ udp_payload_length,
+ off);
+ if ( (NULL == soa->mname) ||
+ (NULL == soa->rname) ||
+ (*off + sizeof (struct GNUNET_TUN_DnsSoaRecord) > udp_payload_length) )
+ {
+ free_soa (soa);
+ *off = old_off;
+ return NULL;
+ }
+ memcpy (&soa_bin,
+ &udp_payload[*off],
+ sizeof (struct GNUNET_TUN_DnsSoaRecord));
+ soa->serial = ntohl (soa_bin.serial);
+ soa->refresh = ntohl (soa_bin.refresh);
+ soa->retry = ntohl (soa_bin.retry);
+ soa->expire = ntohl (soa_bin.expire);
+ soa->minimum_ttl = ntohl (soa_bin.minimum);
+ (*off) += sizeof (struct GNUNET_TUN_DnsSoaRecord);
+ return soa;
+}
+
+
+/**
+ * Parse a DNS MX record.
+ *
+ * @param udp_payload reference to UDP packet
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the query to parse in the MX record (to be
+ * incremented by the size of the record), unchanged on error
+ * @return the parsed MX record, NULL on error
+ */
+struct GNUNET_DNSPARSER_MxRecord *
+GNUNET_DNSPARSER_parse_mx (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off)
+{
+ struct GNUNET_DNSPARSER_MxRecord *mx;
+ uint16_t mxpref;
+ size_t old_off;
+
+ old_off = *off;
+ if (*off + sizeof (uint16_t) > udp_payload_length)
+ return NULL;
+ memcpy (&mxpref, &udp_payload[*off], sizeof (uint16_t));
+ (*off) += sizeof (uint16_t);
+ mx = GNUNET_new (struct GNUNET_DNSPARSER_MxRecord);
+ mx->preference = ntohs (mxpref);
+ mx->mxhost = GNUNET_DNSPARSER_parse_name (udp_payload,
+ udp_payload_length,
+ off);
+ if (NULL == mx->mxhost)
+ {
+ free_mx (mx);
+ *off = old_off;
+ return NULL;
+ }
+ *off = old_off;
+ return mx;
+}
+
+
+/**
+ * Parse a DNS SRV record.
+ *
+ * @param r_name name of the SRV record
+ * @param udp_payload reference to UDP packet
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the query to parse in the SRV record (to be
+ * incremented by the size of the record), unchanged on error
+ * @return the parsed SRV record, NULL on error
+ */
+struct GNUNET_DNSPARSER_SrvRecord *
+GNUNET_DNSPARSER_parse_srv (const char *r_name,
+ const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off)
+{
+ struct GNUNET_DNSPARSER_SrvRecord *srv;
+ struct GNUNET_TUN_DnsSrvRecord srv_bin;
+ size_t old_off;
+ char *ndup;
+ char *tok;
+
+ if ('_' != *r_name)
+ return NULL; /* all valid srv names must start with "_" */
+ if (NULL == strstr (r_name, "._"))
+ return NULL; /* necessary string from "._$PROTO" not present */
+ old_off = *off;
+ if (*off + sizeof (struct GNUNET_TUN_DnsSrvRecord) > udp_payload_length)
+ return NULL;
+ memcpy (&srv_bin,
+ &udp_payload[*off],
+ sizeof (struct GNUNET_TUN_DnsSrvRecord));
+ (*off) += sizeof (struct GNUNET_TUN_DnsSrvRecord);
+ srv = GNUNET_new (struct GNUNET_DNSPARSER_SrvRecord);
+ srv->priority = ntohs (srv_bin.prio);
+ srv->weight = ntohs (srv_bin.weight);
+ srv->port = ntohs (srv_bin.port);
+ /* parse 'data.hostname' into components, which are
+ "_$SERVICE._$PROTO.$DOMAIN_NAME" */
+ ndup = GNUNET_strdup (r_name);
+ tok = strtok (ndup, ".");
+ GNUNET_assert (NULL != tok);
+ GNUNET_assert ('_' == *tok);
+ srv->service = GNUNET_strdup (&tok[1]);
+ tok = strtok (NULL, ".");
+ if ( (NULL == tok) || ('_' != *tok) )
+ {
+ free_srv (srv);
+ GNUNET_free (ndup);
+ *off = old_off;
+ return NULL;
+ }
+ srv->proto = GNUNET_strdup (&tok[1]);
+ tok = strtok (NULL, ".");
+ if (NULL == tok)
+ {
+ free_srv (srv);
+ GNUNET_free (ndup);
+ *off = old_off;
+ return NULL;
+ }
+ srv->domain_name = GNUNET_strdup (tok);
+ GNUNET_free (ndup);
+ srv->target = GNUNET_DNSPARSER_parse_name (udp_payload,
+ udp_payload_length,
+ off);
+ if (NULL == srv->target)
+ {
+ free_srv (srv);
+ *off = old_off;
+ return NULL;
+ }
+ return srv;
+}
+
+
+/**
* Parse a DNS record entry.
*
* @param udp_payload entire UDP payload
@@ -263,25 +524,20 @@ parse_query (const char *udp_payload,
* @param r where to write the record information
* @return #GNUNET_OK on success, #GNUNET_SYSERR if the record is malformed
*/
-static int
-parse_record (const char *udp_payload,
- size_t udp_payload_length,
- size_t *off,
- struct GNUNET_DNSPARSER_Record *r)
+int
+GNUNET_DNSPARSER_parse_record (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off,
+ struct GNUNET_DNSPARSER_Record *r)
{
char *name;
struct GNUNET_TUN_DnsRecordLine rl;
size_t old_off;
- struct GNUNET_TUN_DnsSoaRecord soa;
- uint16_t mxpref;
uint16_t data_len;
- struct GNUNET_TUN_DnsSrvRecord srv;
- char *ndup;
- char *tok;
- name = parse_name (udp_payload,
- udp_payload_length,
- off, 0);
+ name = GNUNET_DNSPARSER_parse_name (udp_payload,
+ udp_payload_length,
+ off);
if (NULL == name)
return GNUNET_SYSERR;
r->name = name;
@@ -296,98 +552,42 @@ parse_record (const char *udp_payload,
data_len = ntohs (rl.data_len);
if (*off + data_len > udp_payload_length)
return GNUNET_SYSERR;
+ old_off = *off;
switch (r->type)
{
case GNUNET_DNSPARSER_TYPE_NS:
case GNUNET_DNSPARSER_TYPE_CNAME:
case GNUNET_DNSPARSER_TYPE_PTR:
- old_off = *off;
- r->data.hostname = parse_name (udp_payload,
- udp_payload_length,
- off, 0);
+ r->data.hostname = GNUNET_DNSPARSER_parse_name (udp_payload,
+ udp_payload_length,
+ off);
if ( (NULL == r->data.hostname) ||
(old_off + data_len != *off) )
return GNUNET_SYSERR;
return GNUNET_OK;
case GNUNET_DNSPARSER_TYPE_SOA:
- old_off = *off;
- r->data.soa = GNUNET_new (struct GNUNET_DNSPARSER_SoaRecord);
- r->data.soa->mname = parse_name (udp_payload,
- udp_payload_length,
- off, 0);
- r->data.soa->rname = parse_name (udp_payload,
- udp_payload_length,
- off, 0);
- if ( (NULL == r->data.soa->mname) ||
- (NULL == r->data.soa->rname) ||
- (*off + sizeof (struct GNUNET_TUN_DnsSoaRecord) > udp_payload_length) )
- return GNUNET_SYSERR;
- memcpy (&soa, &udp_payload[*off], sizeof (struct GNUNET_TUN_DnsSoaRecord));
- r->data.soa->serial = ntohl (soa.serial);
- r->data.soa->refresh = ntohl (soa.refresh);
- r->data.soa->retry = ntohl (soa.retry);
- r->data.soa->expire = ntohl (soa.expire);
- r->data.soa->minimum_ttl = ntohl (soa.minimum);
- (*off) += sizeof (struct GNUNET_TUN_DnsSoaRecord);
- if (old_off + data_len != *off)
+ r->data.soa = GNUNET_DNSPARSER_parse_soa (udp_payload,
+ udp_payload_length,
+ off);
+ if ( (NULL == r->data.soa) ||
+ (old_off + data_len != *off) )
return GNUNET_SYSERR;
return GNUNET_OK;
case GNUNET_DNSPARSER_TYPE_MX:
- old_off = *off;
- if (*off + sizeof (uint16_t) > udp_payload_length)
- return GNUNET_SYSERR;
- memcpy (&mxpref, &udp_payload[*off], sizeof (uint16_t));
- (*off) += sizeof (uint16_t);
- r->data.mx = GNUNET_new (struct GNUNET_DNSPARSER_MxRecord);
- r->data.mx->preference = ntohs (mxpref);
- r->data.mx->mxhost = parse_name (udp_payload,
- udp_payload_length,
- off, 0);
- if (old_off + data_len != *off)
+ r->data.mx = GNUNET_DNSPARSER_parse_mx (udp_payload,
+ udp_payload_length,
+ off);
+ if ( (NULL == r->data.mx) ||
+ (old_off + data_len != *off) )
return GNUNET_SYSERR;
return GNUNET_OK;
case GNUNET_DNSPARSER_TYPE_SRV:
- if ('_' != *r->name)
- return GNUNET_SYSERR; /* all valid srv names must start with "_" */
- if (NULL == strstr (r->name, "._"))
- return GNUNET_SYSERR; /* necessary string from "._$PROTO" not present */
- old_off = *off;
- if (*off + sizeof (struct GNUNET_TUN_DnsSrvRecord) > udp_payload_length)
- return GNUNET_SYSERR;
- memcpy (&srv, &udp_payload[*off], sizeof (struct GNUNET_TUN_DnsSrvRecord));
- (*off) += sizeof (struct GNUNET_TUN_DnsSrvRecord);
- r->data.srv = GNUNET_new (struct GNUNET_DNSPARSER_SrvRecord);
- r->data.srv->priority = ntohs (srv.prio);
- r->data.srv->weight = ntohs (srv.weight);
- r->data.srv->port = ntohs (srv.port);
- /* parse 'data.hostname' into components, which are
- "_$SERVICE._$PROTO.$DOMAIN_NAME" */
- ndup = GNUNET_strdup (r->name);
- tok = strtok (ndup, ".");
- GNUNET_assert (NULL != tok);
- GNUNET_assert ('_' == *tok);
- r->data.srv->service = GNUNET_strdup (&tok[1]);
- tok = strtok (NULL, ".");
- if ( (NULL == tok) || ('_' != *tok) )
- {
- GNUNET_free (r->data.srv);
- GNUNET_free (ndup);
- return GNUNET_SYSERR;
- }
- r->data.srv->proto = GNUNET_strdup (&tok[1]);
- tok = strtok (NULL, ".");
- if (NULL == tok)
- {
- GNUNET_free (r->data.srv);
- GNUNET_free (ndup);
- return GNUNET_SYSERR;
- }
- r->data.srv->domain_name = GNUNET_strdup (tok);
- GNUNET_free (ndup);
- r->data.srv->target = parse_name (udp_payload,
- udp_payload_length,
- off, 0);
- if (old_off + data_len != *off)
+ r->data.srv = GNUNET_DNSPARSER_parse_srv (r->name,
+ udp_payload,
+ udp_payload_length,
+ off);
+ if ( (NULL == r->data.srv) ||
+ (old_off + data_len != *off) )
return GNUNET_SYSERR;
return GNUNET_OK;
default:
@@ -433,10 +633,10 @@ GNUNET_DNSPARSER_parse (const char *udp_payload,
p->num_queries = n;
for (i=0;i<n;i++)
if (GNUNET_OK !=
- parse_query (udp_payload,
- udp_payload_length,
- &off,
- &p->queries[i]))
+ GNUNET_DNSPARSER_parse_query (udp_payload,
+ udp_payload_length,
+ &off,
+ &p->queries[i]))
goto error;
}
n = ntohs (dns->answer_rcount);
@@ -446,10 +646,10 @@ GNUNET_DNSPARSER_parse (const char *udp_payload,
p->num_answers = n;
for (i=0;i<n;i++)
if (GNUNET_OK !=
- parse_record (udp_payload,
- udp_payload_length,
- &off,
- &p->answers[i]))
+ GNUNET_DNSPARSER_parse_record (udp_payload,
+ udp_payload_length,
+ &off,
+ &p->answers[i]))
goto error;
}
n = ntohs (dns->authority_rcount);
@@ -459,10 +659,10 @@ GNUNET_DNSPARSER_parse (const char *udp_payload,
p->num_authority_records = n;
for (i=0;i<n;i++)
if (GNUNET_OK !=
- parse_record (udp_payload,
- udp_payload_length,
- &off,
- &p->authority_records[i]))
+ GNUNET_DNSPARSER_parse_record (udp_payload,
+ udp_payload_length,
+ &off,
+ &p->authority_records[i]))
goto error;
}
n = ntohs (dns->additional_rcount);
@@ -472,10 +672,10 @@ GNUNET_DNSPARSER_parse (const char *udp_payload,
p->num_additional_records = n;
for (i=0;i<n;i++)
if (GNUNET_OK !=
- parse_record (udp_payload,
- udp_payload_length,
- &off,
- &p->additional_records[i]))
+ GNUNET_DNSPARSER_parse_record (udp_payload,
+ udp_payload_length,
+ &off,
+ &p->additional_records[i]))
goto error;
}
return p;
@@ -486,87 +686,6 @@ GNUNET_DNSPARSER_parse (const char *udp_payload,
/**
- * Free SOA information record.
- *
- * @param soa record to free
- */
-static void
-free_soa (struct GNUNET_DNSPARSER_SoaRecord *soa)
-{
- if (NULL == soa)
- return;
- GNUNET_free_non_null (soa->mname);
- GNUNET_free_non_null (soa->rname);
- GNUNET_free (soa);
-}
-
-
-/**
- * Free SRV information record.
- *
- * @param srv record to free
- */
-static void
-free_srv (struct GNUNET_DNSPARSER_SrvRecord *srv)
-{
- if (NULL == srv)
- return;
- GNUNET_free_non_null (srv->target);
- GNUNET_free_non_null (srv->domain_name);
- GNUNET_free_non_null (srv->proto);
- GNUNET_free_non_null (srv->service);
- GNUNET_free (srv);
-}
-
-
-/**
- * Free MX information record.
- *
- * @param mx record to free
- */
-static void
-free_mx (struct GNUNET_DNSPARSER_MxRecord *mx)
-{
- if (NULL == mx)
- return;
- GNUNET_free_non_null (mx->mxhost);
- GNUNET_free (mx);
-}
-
-
-/**
- * Free the given DNS record.
- *
- * @param r record to free
- */
-static void
-free_record (struct GNUNET_DNSPARSER_Record *r)
-{
- GNUNET_free_non_null (r->name);
- switch (r->type)
- {
- case GNUNET_DNSPARSER_TYPE_MX:
- free_mx (r->data.mx);
- break;
- case GNUNET_DNSPARSER_TYPE_SOA:
- free_soa (r->data.soa);
- break;
- case GNUNET_DNSPARSER_TYPE_SRV:
- free_srv (r->data.srv);
- break;
- case GNUNET_DNSPARSER_TYPE_NS:
- case GNUNET_DNSPARSER_TYPE_CNAME:
- case GNUNET_DNSPARSER_TYPE_PTR:
- GNUNET_free_non_null (r->data.hostname);
- break;
- default:
- GNUNET_free_non_null (r->data.raw.data);
- break;
- }
-}
-
-
-/**
* Free memory taken by a packet.
*
* @param p packet to free
diff --git a/src/gns/gnunet-service-gns_resolver.c b/src/gns/gnunet-service-gns_resolver.c
@@ -792,7 +792,7 @@ dns_result_parser (void *cls,
}
/* FIXME: add DNAME support */
- /* convert from DNS to GNS format! */
+ /* convert from (parsed) DNS to (binary) GNS format! */
rd_count = p->num_answers + p->num_authority_records + p->num_additional_records;
{
struct GNUNET_NAMESTORE_RecordData rd[rd_count];
diff --git a/src/include/gnunet_dnsparser_lib.h b/src/include/gnunet_dnsparser_lib.h
@@ -545,5 +545,101 @@ GNUNET_DNSPARSER_builder_add_srv (char *dst,
size_t *off,
const struct GNUNET_DNSPARSER_SrvRecord *srv);
+/* ***************** low-level parsing API ******************** */
+
+/**
+ * Parse a DNS record entry.
+ *
+ * @param udp_payload entire UDP payload
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the record to parse in the udp_payload (to be
+ * incremented by the size of the record)
+ * @param r where to write the record information
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if the record is malformed
+ */
+int
+GNUNET_DNSPARSER_parse_record (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off,
+ struct GNUNET_DNSPARSER_Record *r);
+
+
+/**
+ * Parse name inside of a DNS query or record.
+ *
+ * @param udp_payload entire UDP payload
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the name to parse in the udp_payload (to be
+ * incremented by the size of the name)
+ * @return name as 0-terminated C string on success, NULL if the payload is malformed
+ */
+char *
+GNUNET_DNSPARSER_parse_name (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off);
+
+
+/**
+ * Parse a DNS query entry.
+ *
+ * @param udp_payload entire UDP payload
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the query to parse in the udp_payload (to be
+ * incremented by the size of the query)
+ * @param q where to write the query information
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if the query is malformed
+ */
+int
+GNUNET_DNSPARSER_parse_query (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off,
+ struct GNUNET_DNSPARSER_Query *q);
+
+/**
+ * Parse a DNS SOA record.
+ *
+ * @param udp_payload reference to UDP packet
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the query to parse in the SOA record (to be
+ * incremented by the size of the record), unchanged on error
+ * @return the parsed SOA record, NULL on error
+ */
+struct GNUNET_DNSPARSER_SoaRecord *
+GNUNET_DNSPARSER_parse_soa (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off);
+
+
+/**
+ * Parse a DNS MX record.
+ *
+ * @param udp_payload reference to UDP packet
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the query to parse in the MX record (to be
+ * incremented by the size of the record), unchanged on error
+ * @return the parsed MX record, NULL on error
+ */
+struct GNUNET_DNSPARSER_MxRecord *
+GNUNET_DNSPARSER_parse_mx (const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off);
+
+
+/**
+ * Parse a DNS SRV record.
+ *
+ * @param r_name name of the SRV record
+ * @param udp_payload reference to UDP packet
+ * @param udp_payload_length length of @a udp_payload
+ * @param off pointer to the offset of the query to parse in the SRV record (to be
+ * incremented by the size of the record), unchanged on error
+ * @return the parsed SRV record, NULL on error
+ */
+struct GNUNET_DNSPARSER_SrvRecord *
+GNUNET_DNSPARSER_parse_srv (const char *r_name,
+ const char *udp_payload,
+ size_t udp_payload_length,
+ size_t *off);
+
#endif
