#include "config.h"
#include "iterator/iter_scrub.h"
#include "iterator/iterator.h"
#include "iterator/iter_priv.h"
#include "services/cache/rrset.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/regional.h"
#include "util/config_file.h"
#include "util/module.h"
#include "util/data/msgparse.h"
#include "util/data/dname.h"
#include "util/data/msgreply.h"
#include "util/alloc.h"
Defines | |
#define | RRSET_SCRUB_OK 0x80 |
RRset flag used during scrubbing. | |
Functions | |
static void | remove_rrset (const char *str, ldns_buffer *pkt, struct msg_parse *msg, struct rrset_parse *prev, struct rrset_parse **rrset) |
remove rrset, update loop variables | |
static int | has_additional (uint16_t t) |
return true if rr type has additional names in it | |
static int | get_additional_name (struct rrset_parse *rrset, struct rr_parse *rr, uint8_t **nm, size_t *nmlen, ldns_buffer *pkt) |
get additional name from rrset RR, return false if no name present | |
static void | mark_additional_rrset (ldns_buffer *pkt, struct msg_parse *msg, struct rrset_parse *rrset) |
Place mark on rrsets in additional section they are OK. | |
static int | parse_get_cname_target (struct rrset_parse *rrset, uint8_t **sname, size_t *snamelen) |
Get target name of a CNAME. | |
static int | synth_cname (uint8_t *qname, size_t qnamelen, struct rrset_parse *dname_rrset, uint8_t *alias, size_t *aliaslen, ldns_buffer *pkt) |
Synthesize CNAME from DNAME, false if too long. | |
static struct rrset_parse * | synth_cname_rrset (uint8_t **sname, size_t *snamelen, uint8_t *alias, size_t aliaslen, struct regional *region, struct msg_parse *msg, struct rrset_parse *rrset, struct rrset_parse *prev, struct rrset_parse *nx, ldns_buffer *pkt) |
synthesize a CNAME rrset | |
static int | pkt_strict_sub (ldns_buffer *pkt, uint8_t *sname, uint8_t *dr) |
check if DNAME applies to a name | |
static int | pkt_sub (ldns_buffer *pkt, uint8_t *comprname, uint8_t *zone) |
check subdomain with decompression | |
static int | scrub_normalize (ldns_buffer *pkt, struct msg_parse *msg, struct query_info *qinfo, struct regional *region) |
This routine normalizes a response. | |
static void | store_rrset (ldns_buffer *pkt, struct msg_parse *msg, struct module_env *env, struct rrset_parse *rrset) |
Store potential poison in the cache (only if hardening disabled). | |
static int | sanitize_nsec_is_overreach (struct rrset_parse *rrset, uint8_t *zonename) |
Check if right hand name in NSEC is within zone. | |
static int | scrub_sanitize (ldns_buffer *pkt, struct msg_parse *msg, struct query_info *qinfo, uint8_t *zonename, struct module_env *env, struct iter_env *ie) |
Given a response event, remove suspect RRsets from the response. | |
int | scrub_message (ldns_buffer *pkt, struct msg_parse *msg, struct query_info *qinfo, uint8_t *zonename, struct regional *region, struct module_env *env, struct iter_env *ie) |
Cleanup the passed dns message. |
#define RRSET_SCRUB_OK 0x80 |
RRset flag used during scrubbing.
The RRset is OK.
Referenced by mark_additional_rrset(), and scrub_normalize().
static int scrub_normalize | ( | ldns_buffer * | pkt, | |
struct msg_parse * | msg, | |||
struct query_info * | qinfo, | |||
struct regional * | region | |||
) | [static] |
This routine normalizes a response.
This includes removing "irrelevant" records from the answer and additional sections and (re)synthesizing CNAMEs from DNAMEs, if present.
pkt,: | packet. | |
msg,: | msg to normalize. | |
qinfo,: | original query. | |
region,: | where to allocate synthesized CNAMEs. |
References rrset_parse::dname, dname_pkt_compare(), rrset_parse::flags, msg_parse::flags, FLAGS_GET_RCODE, FLAGS_SET_RCODE, log_err(), mark_additional_rrset(), parse_get_cname_target(), pkt_strict_sub(), query_info::qname, query_info::qname_len, query_info::qtype, remove_rrset(), rrset_parse::rr_count, rrset_parse::rrset_all_next, msg_parse::rrset_first, RRSET_SCRUB_OK, rrset_parse::section, synth_cname(), synth_cname_rrset(), rrset_parse::type, VERB_ALGO, and verbose().
Referenced by scrub_message().
static void store_rrset | ( | ldns_buffer * | pkt, | |
struct msg_parse * | msg, | |||
struct module_env * | env, | |||
struct rrset_parse * | rrset | |||
) | [static] |
Store potential poison in the cache (only if hardening disabled).
The rrset is stored in the cache but removed from the message. So that it will be used for infrastructure purposes, but not be returned to the client.
pkt,: | packet | |
msg,: | message parsed | |
env,: | environment with cache | |
rrset,: | to store. |
References module_env::alloc, alloc_special_obtain(), alloc_special_release(), lruhash_entry::data, ub_packed_rrset_key::entry, ub_packed_rrset_key::id, rrset_ref::id, rrset_ref::key, module_env::now, packed_rrset_ttl_add(), parse_copy_decompress_rrset(), module_env::rrset_cache, and rrset_cache_update().
Referenced by scrub_sanitize().
static int sanitize_nsec_is_overreach | ( | struct rrset_parse * | rrset, | |
uint8_t * | zonename | |||
) | [static] |
Check if right hand name in NSEC is within zone.
rrset,: | the NSEC rrset | |
zonename,: | the zone name. |
References dname_subdomain_c(), dname_valid(), log_assert, rr_parse::next, rrset_parse::rr_first, rr_parse::ttl_data, and rrset_parse::type.
Referenced by scrub_sanitize().
static int scrub_sanitize | ( | ldns_buffer * | pkt, | |
struct msg_parse * | msg, | |||
struct query_info * | qinfo, | |||
uint8_t * | zonename, | |||
struct module_env * | env, | |||
struct iter_env * | ie | |||
) | [static] |
Given a response event, remove suspect RRsets from the response.
"Suspect" rrsets are potentially poison. Note that this routine expects the response to be in a "normalized" state -- that is, all "irrelevant" RRsets have already been removed, CNAMEs are in order, etc.
pkt,: | packet. | |
msg,: | msg to normalize. | |
qinfo,: | the question originally asked. | |
zonename,: | name of server zone. | |
env,: | module environment with config and cache. | |
ie,: | iterator environment with private address data. |
References msg_parse::an_rrsets, module_env::cfg, rrset_parse::dname, dname_pkt_compare(), msg_parse::flags, FLAGS_GET_RCODE, FLAGS_SET_RCODE, config_file::harden_glue, pkt_strict_sub(), pkt_sub(), iter_env::priv, priv_rrset_bad(), query_info::qname, remove_rrset(), rrset_parse::rrset_all_next, msg_parse::rrset_first, sanitize_nsec_is_overreach(), rrset_parse::section, store_rrset(), and rrset_parse::type.
Referenced by scrub_message().
int scrub_message | ( | ldns_buffer * | pkt, | |
struct msg_parse * | msg, | |||
struct query_info * | qinfo, | |||
uint8_t * | zonename, | |||
struct regional * | regional, | |||
struct module_env * | env, | |||
struct iter_env * | ie | |||
) |
Cleanup the passed dns message.
pkt,: | the packet itself, for resolving name compression pointers. the packet buffer is unaltered. | |
msg,: | the parsed packet, this structure is cleaned up. | |
qinfo,: | the query info that was sent to the server. Checked. | |
zonename,: | the name of the last delegation point. Used to determine out of bailiwick information. | |
regional,: | where to allocate (new) parts of the message. | |
env,: | module environment with config settings and cache. | |
ie,: | iterator module environment data. |
References BIT_QR, dname_pkt_compare(), msg_parse::flags, FLAGS_GET_RCODE, log_nametypeclass(), msg_parse::qclass, query_info::qclass, msg_parse::qdcount, query_info::qname, msg_parse::qname, query_info::qtype, msg_parse::qtype, scrub_normalize(), scrub_sanitize(), and VERB_ALGO.
Referenced by process_response().