respip.h File Reference

This file contains a module that selectively modifies query responses based on their AAAA/A IP addresses. More...

#include "util/module.h"
#include "services/localzone.h"
#include "util/locks.h"

Data Structures

struct  respip_set
 Conceptual set of IP addresses for response AAAA or A records that should trigger special actions. More...
struct  resp_addr
 An address span with response control information. More...
struct  respip_client_info
 Client-specific attributes that can affect IP-based actions. More...
struct  respip_action_info
 Data items representing the result of response-ip processing. More...


struct respip_setrespip_set_create (void)
 Create response IP set. More...
void respip_set_delete (struct respip_set *set)
 Delete response IP set. More...
int respip_global_apply_cfg (struct respip_set *set, struct config_file *cfg)
 Apply response-ip config settings to the global (default) view. More...
int respip_views_apply_cfg (struct views *vs, struct config_file *cfg, int *have_view_respip_cfg)
 Apply response-ip config settings in named views. More...
int respip_merge_cname (struct reply_info *base_rep, const struct query_info *qinfo, const struct reply_info *tgt_rep, const struct respip_client_info *cinfo, int must_validate, struct reply_info **new_repp, struct regional *region, struct auth_zones *az)
 Merge two replies to build a complete CNAME chain. More...
int respip_rewrite_reply (const struct query_info *qinfo, const struct respip_client_info *cinfo, const struct reply_info *rep, struct reply_info **new_repp, struct respip_action_info *actinfo, struct ub_packed_rrset_key **alias_rrset, int search_only, struct regional *region, struct auth_zones *az, int *rpz_passthru)
 See if any IP-based action should apply to any IP address of AAAA/A answer record in the reply. More...
struct module_func_blockrespip_get_funcblock (void)
 Get the response-ip function block. More...
int respip_init (struct module_env *env, int id)
 response-ip init
void respip_deinit (struct module_env *env, int id)
 response-ip deinit
void respip_operate (struct module_qstate *qstate, enum module_ev event, int id, struct outbound_entry *outbound)
 response-ip operate on a query
void respip_inform_super (struct module_qstate *qstate, int id, struct module_qstate *super)
 inform response-ip super
void respip_clear (struct module_qstate *qstate, int id)
 response-ip cleanup query state
struct rbtree_typerespip_set_get_tree (struct respip_set *set)
 returns address of the IP address tree of the specified respip set; returns NULL for NULL input; exists for test purposes only
enum respip_action resp_addr_get_action (const struct resp_addr *addr)
 returns respip action for the specified node in the respip address returns respip_none for NULL input; exists for test purposes only
struct ub_packed_rrset_keyresp_addr_get_rrset (struct resp_addr *addr)
 returns rrset portion of the specified node in the respip address tree; returns NULL for NULL input; exists for test purposes only
size_t respip_get_mem (struct module_env *env, int id)
 response-ip alloc size routine
int respip_set_is_empty (const struct respip_set *set)
 respip set emptiness test More...
void respip_inform_print (struct respip_action_info *respip_actinfo, uint8_t *qname, uint16_t qtype, uint16_t qclass, struct local_rrset *local_alias, struct sockaddr_storage *addr, socklen_t addrlen)
 print log information for a query subject to an inform or inform-deny response-ip action. More...
struct resp_addrrespip_sockaddr_find_or_create (struct respip_set *set, struct sockaddr_storage *addr, socklen_t addrlen, int net, int create, const char *ipstr)
 Find resp_addr in tree, create and add to tree if it does not exist. More...
int respip_enter_rr (struct regional *region, struct resp_addr *raddr, uint16_t rrtype, uint16_t rrclass, time_t ttl, uint8_t *rdata, size_t rdata_len, const char *rrstr, const char *netblockstr)
 Add RR to resp_addr's RRset. More...
void respip_sockaddr_delete (struct respip_set *set, struct resp_addr *node)
 Delete resp_addr node from tree. More...
struct ub_packed_rrset_keyrespip_copy_rrset (const struct ub_packed_rrset_key *key, struct regional *region)
 make a deep copy of 'key' in 'region'. More...

Detailed Description

This file contains a module that selectively modifies query responses based on their AAAA/A IP addresses.

Function Documentation

◆ respip_set_create()

struct respip_set* respip_set_create ( void  )

Create response IP set.

new struct or NULL on error.

References addr_tree_init(), and regional_create().

Referenced by respip_conf_actions_test(), respip_conf_data_test(), respip_views_apply_cfg(), and rpz_create().

◆ respip_set_delete()

void respip_set_delete ( struct respip_set set)

Delete response IP set.

setto delete.

◆ respip_global_apply_cfg()

int respip_global_apply_cfg ( struct respip_set set,
struct config_file cfg 

Apply response-ip config settings to the global (default) view.

It assumes exclusive access to set (no internal locks).

setprocessed global respip config data
cfgconfig data.
1 on success, 0 on error.

Referenced by respip_conf_data_test().

◆ respip_views_apply_cfg()

int respip_views_apply_cfg ( struct views vs,
struct config_file cfg,
int *  have_view_respip_cfg 

Apply response-ip config settings in named views.

vsview structures with processed config data
cfgconfig data.
have_view_respip_cfgset to true if any named view has respip configuration; otherwise set to false
1 on success, 0 on error.

Apply response-ip config settings in named views.

This additional iteration through view configuration data is expected to not have significant performance impact (or rather, its performance impact is not expected to be prohibitive in the configuration processing phase).

if no respip config for this view then there's nothing to do; note that even though respip data must go with respip action, we're checking for both here because we want to catch the case where the respip action is missing while the data is present

References view::lock, log_err(), config_view::name, config_view::next, config_view::respip_actions, config_view::respip_data, view::respip_set, respip_set_create(), config_file::views, and views_find_view().

Referenced by respip_view_conf_data_test().

◆ respip_merge_cname()

int respip_merge_cname ( struct reply_info base_rep,
const struct query_info qinfo,
const struct reply_info tgt_rep,
const struct respip_client_info cinfo,
int  must_validate,
struct reply_info **  new_repp,
struct regional region,
struct auth_zones az 

Merge two replies to build a complete CNAME chain.

It appends the content of 'tgt_rep' to 'base_rep', assuming (but not checking) the former ends with a CNAME and the latter resolves its target. A merged new reply will be built using 'region' and *new_repp will point to the new one on success. If the target reply would also be subject to a response-ip action for 'cinfo', this function uses 'base_rep' as the merged reply, ignoring 'tgt_rep'. This is for avoiding cases like a CNAME loop or failure of applying an action to an address. RRSIGs in 'tgt_rep' will be excluded in the merged reply, as the resulting reply is assumed to be faked due to a response-ip action and can't be considered secure in terms of DNSSEC. The caller must ensure that neither 'base_rep' nor 'tgt_rep' can be modified until this function returns.

base_repthe reply info containing an incomplete CNAME.
qinfoquery info corresponding to 'base_rep'.
tgt_repthe reply info that completes the CNAME chain.
cinfoclient info corresponding to 'base_rep'.
must_validatewhether 'tgt_rep' must be DNSSEC-validated.
new_repppointer placeholder for the merged reply. will be intact on error.
regionallocator to build *new_repp.
azauth zones containing RPZ information.
1 on success, 0 on error.

References reply_info::flags, FLAGS_GET_RCODE, and respip_none.

Referenced by mesh_serve_expired_callback().

◆ respip_rewrite_reply()

int respip_rewrite_reply ( const struct query_info qinfo,
const struct respip_client_info cinfo,
const struct reply_info rep,
struct reply_info **  new_repp,
struct respip_action_info actinfo,
struct ub_packed_rrset_key **  alias_rrset,
int  search_only,
struct regional region,
struct auth_zones az,
int *  rpz_passthru 

See if any IP-based action should apply to any IP address of AAAA/A answer record in the reply.

If so, apply the action. In some cases it rewrites the reply rrsets, in which case *new_repp will point to the updated reply info. Depending on the action, some of the rrsets in 'rep' will be shallow-copied into '*new_repp'; the caller must ensure that the rrsets in 'rep' are valid throughout the lifetime of *new_repp, and it must provide appropriate mutex if the rrsets can be shared by multiple threads.

qinfoquery info corresponding to the reply.
cinfoclient-specific info to identify the best matching action. can be NULL.
reporiginal reply info. must not be NULL.
new_reppcan be set to the rewritten reply info (intact on failure).
actinforesult of response-ip processing
alias_rrsetmust not be NULL.
search_onlyif true, only check if an action would apply. actionp will be set (or intact) accordingly but the modified reply won't be built.
azauth zones containing RPZ information.
regionallocator to build *new_repp.
rpz_passthrukeeps track of query state can have passthru that stops further rpz processing. Or NULL for cached answer processing.
1 on success, 0 on error.

Try to use response-ip config from the view first; use global response-ip config if we don't have the view or we don't have the matching per-view config (and the view allows the use of global data in this case). Note that we lock the view even if we only use view members that currently don't change after creation. This is for safety for future possible changes as the view documentation seems to expect any of its member can change in the view's lifetime. Note also that we assume 'view' is valid in this function, which should be safe (see unbound bug #1191)

for per-view respip directives the action can only be direct (i.e. not tag-based)

References resp_addr::action, view::isfirst, local_data_find_tag_action(), auth_zone::lock, view::lock, log_assert, respip_addr_lookup(), respip_none, view::respip_set, auth_zone::rpz, auth_zone::rpz_az_next, auth_zones::rpz_first, auth_zones::rpz_lock, resp_addr::taglen, resp_addr::taglist, and taglist_intersect().

Referenced by apply_respip_action(), and respip_operate().

◆ respip_get_funcblock()

struct module_func_block* respip_get_funcblock ( void  )

Get the response-ip function block.

: function block with function pointers to response-ip methods.

Referenced by module_funcs_avail().

◆ respip_set_is_empty()

int respip_set_is_empty ( const struct respip_set set)

respip set emptiness test

setrespip set to test
0 if the specified set exists (non-NULL) and is non-empty; otherwise returns 1

References rbtree_type::count.

◆ respip_inform_print()

void respip_inform_print ( struct respip_action_info respip_actinfo,
uint8_t *  qname,
uint16_t  qtype,
uint16_t  qclass,
struct local_rrset local_alias,
struct sockaddr_storage *  addr,
socklen_t  addrlen 

print log information for a query subject to an inform or inform-deny response-ip action.

respip_actinforesponse-ip information that causes the action
qnamequery name in the context, will be ignored if local_alias is non-NULL.
qtypequery type, in host byte order.
qclassquery class, in host byte order.
local_aliasset to a local alias if the query matches an alias in a local zone. In this case its owner name will be considered the actual query name.
addrthe client's source address and port.
addrlenthe client's source address length.

References addr_to_str(), packed_rrset_key::dname, ub_packed_rrset_key::rk, rpz_action_to_string(), and local_rrset::rrset.

Referenced by apply_respip_action(), and mesh_serve_expired_callback().

◆ respip_sockaddr_find_or_create()

struct resp_addr* respip_sockaddr_find_or_create ( struct respip_set set,
struct sockaddr_storage *  addr,
socklen_t  addrlen,
int  net,
int  create,
const char *  ipstr 

Find resp_addr in tree, create and add to tree if it does not exist.

setstruct containing the tree and region to alloc new node on. should hold write lock.
addraddress to look up.
addrlenlength of addr.
netnetblock to lookup.
createcreate node if it does not exist when 1.
ipstrhuman redable ip string, for logging.
newly created of found node, not holding lock.

References addr_tree_find(), addr_tree_insert(), log_err(), log_warn(), resp_addr::node, addr_tree_node::node, regional_alloc_zero(), and respip_none.

Referenced by respip_find_or_create().

◆ respip_enter_rr()

int respip_enter_rr ( struct regional region,
struct resp_addr raddr,
uint16_t  rrtype,
uint16_t  rrclass,
time_t  ttl,
uint8_t *  rdata,
size_t  rdata_len,
const char *  rrstr,
const char *  netblockstr 

Add RR to resp_addr's RRset.

Create RRset if not existing.

regionregion to alloc RR(set).
raddrresp_addr containing RRset. Must hold write lock.
rrtypeRR type.
rrclassRR class.
rdata_lenlength of rdata.
rrstrRR as string, for logging
netblockstrnetblock as string, for logging
0 on error

Add RR to resp_addr's RRset.

References addr_tree_node::addr, resp_addr::data, lruhash_entry::data, ub_packed_rrset_key::entry, LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, LDNS_RR_TYPE_CNAME, log_err(), new_rrset(), resp_addr::node, ub_packed_rrset_key::rk, rrset_insert_rr(), and packed_rrset_key::type.

◆ respip_sockaddr_delete()

void respip_sockaddr_delete ( struct respip_set set,
struct resp_addr node 

Delete resp_addr node from tree.

setstruct containing tree. Must hold write lock.
nodenode to delete. Not locked.

References addr_tree_init_parents(), addr_tree_init_parents_node(), resp_addr::node, rbtree_delete(), and rbtree_previous().

◆ respip_copy_rrset()

struct ub_packed_rrset_key* respip_copy_rrset ( const struct ub_packed_rrset_key key,
struct regional region 

make a deep copy of 'key' in 'region'.

This is largely derived from packed_rrset_copy_region() and packed_rrset_ptr_fixup(), but differs in the following points:

  • It doesn't assume all data in 'key' are in a contiguous memory region. Although that would be the case in most cases, 'key' can be passed from a lower-level module and it might not build the rrset to meet the assumption. In fact, an rrset specified as response-ip-data or generated in local_data_find_tag_datas() breaks the assumption. So it would be safer not to naively rely on the assumption. On the other hand, this function ensures the copied rrset data are in a contiguous region so that it won't cause a disruption even if an upper layer module naively assumes the memory layout.
  • It doesn't copy RRSIGs (if any) in 'key'. The rrset will be used in a reply that was already faked, so it doesn't make much sense to provide partial sigs even if they are valid themselves.
  • It doesn't adjust TTLs as it basically has to be a verbatim copy of 'key' just allocated in 'region' (the assumption is necessary TTL adjustment has been already done in 'key').

This function returns the copied rrset key on success, and NULL on memory allocation failure.

References packed_rrset_data::count, lruhash_entry::data, packed_rrset_key::dname, packed_rrset_key::dname_len, ub_packed_rrset_key::entry, lruhash_entry::hash, ub_packed_rrset_key::id, lruhash_entry::key, regional_alloc(), regional_alloc_init(), regional_alloc_zero(), ub_packed_rrset_key::rk, packed_rrset_data::rr_data, packed_rrset_data::rr_len, packed_rrset_data::rr_ttl, and packed_rrset_data::rrsig_count.

Referenced by make_soa_ubrrset(), respip_data_answer(), and rpz_apply_cname_override_action().