/*
* util/edns.c - handle base EDNS options.
*
* Copyright (c) 2018, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains functions for base EDNS options.
*/
#include "config.h"
#include "util/edns.h"
#include "util/config_file.h"
#include "util/netevent.h"
#include "util/net_help.h"
#include "util/regional.h"
#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);
}
static int
edns_tags_client_insert(struct edns_tags* edns_tags,
struct sockaddr_storage* addr, socklen_t addrlen, int net,
uint16_t tag_data)
{
struct edns_tag_addr* eta = regional_alloc_zero(edns_tags->region,
sizeof(struct edns_tag_addr));
if(!eta)
return 0;
eta->tag_data = tag_data;
if(!addr_tree_insert(&edns_tags->client_tags, &eta->node, addr, addrlen,
net)) {
verbose(VERB_QUERY, "duplicate EDNS client tag ignored.");
}
return 1;
}
int edns_tags_apply_cfg(struct edns_tags* edns_tags,
struct config_file* config)
{
struct config_str2list* c;
regional_free_all(edns_tags->region);
addr_tree_init(&edns_tags->client_tags);
for(c=config->edns_client_tags; c; c=c->next) {
struct sockaddr_storage addr;
socklen_t addrlen;
int net;
uint16_t tag_data;
log_assert(c->str && c->str2);
if(!netblockstrtoaddr(c->str, UNBOUND_DNS_PORT, &addr, &addrlen,
&net)) {
log_err("cannot parse EDNS client tag IP netblock: %s",
c->str);
return 0;
}
tag_data = atoi(c->str2); /* validated in config parser */
if(!edns_tags_client_insert(edns_tags, &addr, addrlen, net,
tag_data)) {
log_err("out of memory while adding EDNS tags");
return 0;
}
}
edns_tags->client_tag_opcode = config->edns_client_tag_opcode;
addr_tree_init_parents(&edns_tags->client_tags);
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)
{
if(c->type == comm_udp)
return 1;
/* To respond with a Keepalive option, the client connection
* must have received one message with a TCP Keepalive EDNS option,
* and that option must have 0 length data. Subsequent messages
* sent on that connection will have a TCP Keepalive option.
*/
if(c->tcp_keepalive ||
edns_opt_list_find(edns_in->opt_list, LDNS_EDNS_KEEPALIVE)) {
int keepalive = c->tcp_timeout_msec / 100;
uint8_t data[2];
data[0] = (uint8_t)((keepalive >> 8) & 0xff);
data[1] = (uint8_t)(keepalive & 0xff);
if(!edns_opt_list_append(&edns_out->opt_list, LDNS_EDNS_KEEPALIVE,
sizeof(data), data, region))
return 0;
c->tcp_keepalive = 1;
}
return 1;
}
int apply_edns_options(struct edns_data* edns_out, struct edns_data* edns_in,
struct config_file* cfg, struct comm_point* c, struct regional* region)
{
if(cfg->do_tcp_keepalive &&
!edns_keepalive(edns_out, edns_in, c, region))
return 0;
return 1;
}
