/*
* respip/respip.h - IP-based response modification module
*/
/**
* \file
*
* This file contains a module that selectively modifies query responses
* based on their AAAA/A IP addresses.
*/
#ifndef RESPIP_RESPIP_H
#define RESPIP_RESPIP_H
#include "util/module.h"
#include "services/localzone.h"
/**
* Set of response IP addresses with associated actions and tags.
* Forward declaration only here. Actual definition is hidden within the
* module.
*/
struct respip_set;
/**
* Forward declaration for the structure that represents a node in the
* respip_set address tree
*/
struct resp_addr;
/**
* Forward declaration for the structure that represents a tree of view data.
*/
struct views;
struct respip_addr_info;
/**
* Client-specific attributes that can affect IP-based actions.
* This is essentially a subset of acl_addr (except for respip_set) but
* defined as a separate structure to avoid dependency on the daemon-specific
* structure.
* respip_set is supposed to refer to the response-ip set for the global view.
*/
struct respip_client_info {
uint8_t* taglist;
size_t taglen;
uint8_t* tag_actions;
size_t tag_actions_size;
struct config_strlist** tag_datas;
size_t tag_datas_size;
struct view* view;
struct respip_set* respip_set;
};
/**
* Data items representing the result of response-ip processing.
* Note: this structure currently only define a few members, but exists
* as a separate struct mainly for the convenience of custom extensions.
*/
struct respip_action_info {
enum respip_action action;
struct respip_addr_info* addrinfo; /* set only for inform variants */
};
/**
* Forward declaration for the structure that represents a node in the
* respip_set address tree
*/
struct resp_addr;
/**
* Create response IP set.
* @return new struct or NULL on error.
*/
struct respip_set* respip_set_create(void);
/**
* Delete response IP set.
* @param set: to delete.
*/
void respip_set_delete(struct respip_set* set);
/**
* Apply response-ip config settings to the global (default) view.
* It assumes exclusive access to set (no internal locks).
* @param set: processed global respip config data
* @param cfg: config data.
* @return 1 on success, 0 on error.
*/
int respip_global_apply_cfg(struct respip_set* set, struct config_file* cfg);
/**
* Apply response-ip config settings in named views.
* @param vs: view structures with processed config data
* @param cfg: config data.
* @param have_view_respip_cfg: set to true if any named view has respip
* configuration; otherwise set to false
* @return 1 on success, 0 on error.
*/
int respip_views_apply_cfg(struct views* vs, struct config_file* cfg,
int* have_view_respip_cfg);
/**
* 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.
* @param base_rep: the reply info containing an incomplete CNAME.
* @param qinfo: query info corresponding to 'base_rep'.
* @param tgt_rep: the reply info that completes the CNAME chain.
* @param cinfo: client info corresponding to 'base_rep'.
* @param must_validate: whether 'tgt_rep' must be DNSSEC-validated.
* @param new_repp: pointer placeholder for the merged reply. will be intact
* on error.
* @param region: allocator to build *new_repp.
* @return 1 on success, 0 on error.
*/
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);
/**
* 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.
* @param qinfo: query info corresponding to the reply.
* @param cinfo: client-specific info to identify the best matching action.
* can be NULL.
* @param rep: original reply info. must not be NULL.
* @param new_repp: can be set to the rewritten reply info (intact on failure).
* @param actinfo: result of response-ip processing
* @param alias_rrset: must not be NULL.
* @param 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.
* @param region: allocator to build *new_repp.
* @return 1 on success, 0 on error.
*/
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);
/**
* Get the response-ip function block.
* @return: function block with function pointers to response-ip methods.
*/
struct module_func_block* respip_get_funcblock(void);
/** response-ip init */
int respip_init(struct module_env* env, int id);
/** response-ip deinit */
void respip_deinit(struct module_env* env, int id);
/** response-ip operate on a query */
void respip_operate(struct module_qstate* qstate, enum module_ev event, int id,
struct outbound_entry* outbound);
/** inform response-ip super */
void respip_inform_super(struct module_qstate* qstate, int id,
struct module_qstate* super);
/** response-ip cleanup query state */
void respip_clear(struct module_qstate* qstate, int id);
/**
* returns address of the IP address tree of the specified respip set;
* returns NULL for NULL input; exists for test purposes only
*/
struct rbtree_type* respip_set_get_tree(struct respip_set* set);
/**
* returns respip action for the specified node in the respip address
* returns respip_none for NULL input; exists for test purposes only
*/
enum respip_action resp_addr_get_action(const 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
*/
struct ub_packed_rrset_key* resp_addr_get_rrset(struct resp_addr* addr);
/** response-ip alloc size routine */
size_t respip_get_mem(struct module_env* env, int id);
/**
* respip set emptiness test
* @param set respip set to test
* @return 0 if the specified set exists (non-NULL) and is non-empty;
* otherwise returns 1
*/
int respip_set_is_empty(const struct respip_set* set);
/**
* print log information for a query subject to an inform or inform-deny
* response-ip action.
* @param respip_addr: response-ip information that causes the action
* @param qname: query name in the context, will be ignored if local_alias is
* non-NULL.
* @param qtype: query type, in host byte order.
* @param qclass: query class, in host byte order.
* @param 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.
* @param repinfo: reply info containing the client's source address and port.
*/
void respip_inform_print(struct respip_addr_info* respip_addr, uint8_t* qname,
uint16_t qtype, uint16_t qclass, struct local_rrset* local_alias,
struct comm_reply* repinfo);
#endif /* RESPIP_RESPIP_H */
