Start of EDNS client tags implementation.

daemon/daemon.c

@@ -77,6 +77,7 @@
 #include "util/storage/lookup3.h"
 #include "util/storage/slabhash.h"
 #include "util/tcp_conn_limit.h"
+#include "util/edns.h"
 #include "services/listen_dnsport.h"
 #include "services/cache/rrset.h"
 #include "services/cache/infra.h"
@@ -290,6 +291,15 @@ daemon_init(void)
 		free(daemon);
 		return NULL;
 	}
+	if(!(daemon->env->edns_tags = edns_tags_create())) {
+		auth_zones_delete(daemon->env->auth_zones);
+		acl_list_delete(daemon->acl);
+		tcl_list_delete(daemon->tcl);
+		edns_known_options_delete(daemon->env);
+		free(daemon->env);
+		free(daemon);
+		return NULL;
+	}
 	return daemon;	
 }
 
@@ -619,6 +629,10 @@ daemon_fork(struct daemon* daemon)
 		&daemon->use_rpz))
 		fatal_exit("auth_zones could not be setup");
 
+	/* Set-up EDNS tags */
+	if(!edns_tags_apply_cfg(daemon->env->edns_tags, daemon->cfg))
+		fatal_exit("Could not set up EDNS tags");
+
 	/* setup modules */
 	daemon_setup_modules(daemon);
 
@@ -750,6 +764,7 @@ daemon_delete(struct daemon* daemon)
 		rrset_cache_delete(daemon->env->rrset_cache);
 		infra_delete(daemon->env->infra_cache);
 		edns_known_options_delete(daemon->env);
+		edns_tags_delete(daemon->env->edns_tags);
 		auth_zones_delete(daemon->env->auth_zones);
 	}
 	ub_randfree(daemon->rand);

services/outside_network.c

@@ -58,6 +58,7 @@
 #include "util/net_help.h"
 #include "util/random.h"
 #include "util/fptr_wlist.h"
+#include "util/edns.h"
 #include "sldns/sbuffer.h"
 #include "dnstap/dnstap.h"
 #ifdef HAVE_OPENSSL_SSL_H
@@ -2111,9 +2112,20 @@ outnet_serviced_query(struct outside_network* outnet,
 {
 	struct serviced_query* sq;
 	struct service_callback* cb;
+	struct edns_tag_addr* client_tag_addr;
+
 	if(!inplace_cb_query_call(env, qinfo, flags, addr, addrlen, zone, zonelen,
 		qstate, qstate->region))
 			return NULL;
+
+	if((client_tag_addr = edns_tag_addr_lookup(env->edns_tags->client_tags,
+		addr, addrlen))) {
+		uint16_t client_tag = htons(client_tag_addr->tag_data);
+		edns_opt_list_append(&qstate->edns_opts_back_out,
+			LDNS_EDNS_CLIENT_TAG, 2,
+			(uint8_t*)&client_tag, qstate->region);
+	}
+
 	serviced_gen_query(buff, qinfo->qname, qinfo->qname_len, qinfo->qtype,
 		qinfo->qclass, flags);
 	sq = lookup_serviced(outnet, buff, dnssec, addr, addrlen,

sldns/rrdef.h

@@ -426,7 +426,8 @@ enum sldns_enum_edns_option
 	LDNS_EDNS_N3U = 7, /* RFC6975 */
 	LDNS_EDNS_CLIENT_SUBNET = 8, /* RFC7871 */
 	LDNS_EDNS_KEEPALIVE = 11, /* draft-ietf-dnsop-edns-tcp-keepalive*/
-	LDNS_EDNS_PADDING = 12 /* RFC7830 */
+	LDNS_EDNS_PADDING = 12, /* RFC7830 */
+	LDNS_EDNS_CLIENT_TAG = 16 /* draft-bellis-dnsop-edns-tags-01 */
 };
 typedef enum sldns_enum_edns_option sldns_edns_option;
 

util/edns.c

@@ -47,6 +47,44 @@
 #include "util/data/msgparse.h"
 #include "util/data/msgreply.h"
 
+struct edns_tags* edns_tags_create(void)
+{
+	struct edns_tags* edns_tags = calloc(1, sizeof(struct edns_tags));
+	if(!edns_tags)
+		return NULL;
+	if(!(edns_tags->region = regional_create())) {
+		edns_tags_delete(edns_tags);
+		return NULL;
+	}
+	return edns_tags;
+}
+
+void edns_tags_delete(struct edns_tags* edns_tags)
+{
+	if(!edns_tags)
+		return;
+	regional_destroy(edns_tags->region);
+	free(edns_tags);
+}
+
+int edns_tags_apply_cfg(struct edns_tags* edns_tags,
+	struct config_file* config)
+{
+	regional_free_all(edns_tags->region);
+	addr_tree_init(&edns_tags->client_tags);
+
+	/* TODO walk over config, create and insert node. */
+
+	return 1;
+}
+
+struct edns_tag_addr*
+edns_tag_addr_lookup(rbtree_type tree, struct sockaddr_storage* addr,
+	socklen_t addrlen)
+{
+	return (struct edns_tag_addr*)addr_tree_lookup(&tree, addr, addrlen);
+}
+
 static int edns_keepalive(struct edns_data* edns_out, struct edns_data* edns_in,
 		struct comm_point* c, struct regional* region)
 {

util/edns.h

@@ -42,11 +42,66 @@
 #ifndef UTIL_EDNS_H
 #define UTIL_EDNS_H
 
+#include "util/storage/dnstree.h"
+
 struct edns_data;
 struct config_file;
 struct comm_point;
 struct regional;
 
+/**
+ * Structure containing all EDNS tags.
+ */
+struct edns_tags {
+	/** Tree of EDNS client tags to use in upstream queries, per address
+	 * prefix. Contains nodes of type edns_tag_addr. */
+	rbtree_type client_tags;
+	/** region to allocate tree nodes in */
+	struct regional* region;
+};
+
+/**
+ * EDNS tag. Node of rbtree, containing tag and prefix.
+ */
+struct edns_tag_addr {
+	/** node in address tree, used for tree lookups. Need to be the first
+	 * member of this struct. */
+	struct addr_tree_node node;
+	/** tag data, in host byte ordering */
+	uint16_t tag_data;
+};
+
+/**
+ * Create structure to hold EDNS tags
+ * @return: newly created edns_tags, NULL on alloc failure.
+ */
+struct edns_tags* edns_tags_create(void);
+
+/** Delete ENDS tags structure
+ * @param edns_tags: struct to delete
+ */
+void edns_tags_delete(struct edns_tags* edns_tags);
+
+/**
+ * Add configured EDNS tags
+ * @param edns_tags: edns tags to apply config to
+ * @param config: struct containing EDNS tags configuration
+ * @return 0 on error
+ */
+int edns_tags_apply_cfg(struct edns_tags* edns_tags,
+	struct config_file* config);
+
+/**
+ * Find tag for address.
+ * @param tree: tree containing EDNS tags per address prefix.
+ * @param addr: address to use for tree lookup
+ * @param addrlen: length of address
+ * @return: matching tree node, NULL otherwise
+ */
+struct edns_tag_addr*
+edns_tag_addr_lookup(rbtree_type tree, struct sockaddr_storage* addr,
+	socklen_t addrlen);
+
 /**
  * Apply common EDNS options.
  *

util/module.h

@@ -520,6 +520,7 @@ struct module_env {
 	struct edns_known_option* edns_known_options;
 	/* Number of known edns options */
 	size_t edns_known_options_num;
+	struct edns_tags* edns_tags;
 
 	/* Make every mesh state unique, do not aggregate mesh states. */
 	int unique_mesh;