tor/src/or/dns.h
Nick Mathewson 609065f165 DefecTor countermeasure: change server- and client-side DNS TTL clipping
The server-side clipping now clamps to one of two values, both
for what to report, and how long to cache.

Additionally, we move some defines to dns.h, and give them better
names.
2017-01-18 08:55:57 -05:00

71 lines
2.2 KiB
C

/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2016, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file dns.h
* \brief Header file for dns.c.
**/
#ifndef TOR_DNS_H
#define TOR_DNS_H
/** Lowest value for DNS ttl that a server will give. */
#define MIN_DNS_TTL_AT_EXIT (5*60)
/** Highest value for DNS ttl that a server will give. */
#define MAX_DNS_TTL_AT_EXIT (60*60)
/** How long do we keep DNS cache entries before purging them (regardless of
* their TTL)? */
#define MAX_DNS_ENTRY_AGE (3*60*60)
/** How long do we cache/tell clients to cache DNS records when no TTL is
* known? */
#define DEFAULT_DNS_TTL (30*60)
int dns_init(void);
int has_dns_init_failed(void);
void dns_free_all(void);
uint32_t dns_clip_ttl(uint32_t ttl);
int dns_reset(void);
void connection_dns_remove(edge_connection_t *conn);
void assert_connection_edge_not_dns_pending(edge_connection_t *conn);
void assert_all_pending_dns_resolves_ok(void);
MOCK_DECL(void,dns_cancel_pending_resolve,(const char *question));
int dns_resolve(edge_connection_t *exitconn);
void dns_launch_correctness_checks(void);
int dns_seems_to_be_broken(void);
int dns_seems_to_be_broken_for_ipv6(void);
void dns_reset_correctness_checks(void);
void dump_dns_mem_usage(int severity);
#ifdef DNS_PRIVATE
#include "dns_structs.h"
MOCK_DECL(STATIC int,dns_resolve_impl,(edge_connection_t *exitconn,
int is_resolve,or_circuit_t *oncirc, char **hostname_out,
int *made_connection_pending_out, cached_resolve_t **resolve_out));
MOCK_DECL(STATIC void,send_resolved_cell,(edge_connection_t *conn,
uint8_t answer_type,const cached_resolve_t *resolved));
MOCK_DECL(STATIC void,send_resolved_hostname_cell,(edge_connection_t *conn,
const char *hostname));
cached_resolve_t *dns_get_cache_entry(cached_resolve_t *query);
void dns_insert_cache_entry(cached_resolve_t *new_entry);
MOCK_DECL(STATIC int,
set_exitconn_info_from_resolve,(edge_connection_t *exitconn,
const cached_resolve_t *resolve,
char **hostname_out));
MOCK_DECL(STATIC int,
launch_resolve,(cached_resolve_t *resolve));
#endif
#endif