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...

Functions
struct respip_set *	respip_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_block *	respip_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_type *	respip_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_key *	resp_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_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. 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_key *	respip_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.

Returns

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.

Parameters

set	to 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).

Parameters

set	processed global respip config data
cfg	config data.

Returns

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.

Parameters

vs	view structures with processed config data
cfg	config data.
have_view_respip_cfg	set to true if any named view has respip configuration; otherwise set to false

Returns

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.

Parameters

base_rep	the reply info containing an incomplete CNAME.
qinfo	query info corresponding to 'base_rep'.
tgt_rep	the reply info that completes the CNAME chain.
cinfo	client info corresponding to 'base_rep'.
must_validate	whether 'tgt_rep' must be DNSSEC-validated.
new_repp	pointer placeholder for the merged reply. will be intact on error.
region	allocator to build *new_repp.
az	auth zones containing RPZ information.

Returns

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.

Parameters

qinfo	query info corresponding to the reply.
cinfo	client-specific info to identify the best matching action. can be NULL.
rep	original reply info. must not be NULL.
new_repp	can be set to the rewritten reply info (intact on failure).
actinfo	result of response-ip processing
alias_rrset	must not be NULL.
search_only	if true, only check if an action would apply. actionp will be set (or intact) accordingly but the modified reply won't be built.
az	auth zones containing RPZ information.
region	allocator to build *new_repp.
rpz_passthru	keeps track of query state can have passthru that stops further rpz processing. Or NULL for cached answer processing.

Returns

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.

Returns

: 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

Parameters

set	respip set to test

Returns

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.

Parameters

respip_actinfo	response-ip information that causes the action
qname	query name in the context, will be ignored if local_alias is non-NULL.
qtype	query type, in host byte order.
qclass	query class, in host byte order.
local_alias	set 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.
addr	the client's source address and port.
addrlen	the 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.

Parameters

set	struct containing the tree and region to alloc new node on. should hold write lock.
addr	address to look up.
addrlen	length of addr.
net	netblock to lookup.
create	create node if it does not exist when 1.
ipstr	human redable ip string, for logging.

Returns

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.

Parameters

region	region to alloc RR(set).
raddr	resp_addr containing RRset. Must hold write lock.
rrtype	RR type.
rrclass	RR class.
ttl	TTL.
rdata	RDATA.
rdata_len	length of rdata.
rrstr	RR as string, for logging
netblockstr	netblock as string, for logging

Returns

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.

Parameters

set	struct containing tree. Must hold write lock.
node	node 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(), and respip_data_answer().