2 * respip/respip.h - IP-based response modification module
8 * This file contains a module that selectively modifies query responses
9 * based on their AAAA/A IP addresses.
12 #ifndef RESPIP_RESPIP_H
13 #define RESPIP_RESPIP_H
15 #include "util/module.h"
16 #include "services/localzone.h"
17 #include "util/locks.h"
20 * Conceptual set of IP addresses for response AAAA or A records that should
21 * trigger special actions.
24 struct regional* region;
25 struct rbtree_type ip_tree;
26 lock_rw_type lock; /* lock on the respip tree */
27 char* const* tagname; /* shallow copy of tag names, for logging */
28 int num_tags; /* number of tagname entries */
32 /** An address span with response control information */
34 /** node in address tree */
35 struct addr_tree_node node;
36 /** lock on the node item */
40 /** length of the taglist (in bytes) */
42 /** action for this address span */
43 enum respip_action action;
44 /** "local data" for this node */
45 struct ub_packed_rrset_key* data;
50 * Forward declaration for the structure that represents a tree of view data.
55 struct respip_addr_info;
58 * Client-specific attributes that can affect IP-based actions.
59 * This is essentially a subset of acl_addr (except for respip_set) but
60 * defined as a separate structure to avoid dependency on the daemon-specific
62 * respip_set is supposed to refer to the response-ip set for the global view.
64 struct respip_client_info {
68 size_t tag_actions_size;
69 struct config_strlist** tag_datas;
70 size_t tag_datas_size;
72 struct respip_set* respip_set;
76 * Data items representing the result of response-ip processing.
77 * Note: this structure currently only define a few members, but exists
78 * as a separate struct mainly for the convenience of custom extensions.
80 struct respip_action_info {
81 enum respip_action action;
86 int rpz_cname_override;
87 struct respip_addr_info* addrinfo; /* set only for inform variants */
91 * Forward declaration for the structure that represents a node in the
92 * respip_set address tree
97 * Create response IP set.
98 * @return new struct or NULL on error.
100 struct respip_set* respip_set_create(void);
103 * Delete response IP set.
104 * @param set: to delete.
106 void respip_set_delete(struct respip_set* set);
109 * Apply response-ip config settings to the global (default) view.
110 * It assumes exclusive access to set (no internal locks).
111 * @param set: processed global respip config data
112 * @param cfg: config data.
113 * @return 1 on success, 0 on error.
115 int respip_global_apply_cfg(struct respip_set* set, struct config_file* cfg);
118 * Apply response-ip config settings in named views.
119 * @param vs: view structures with processed config data
120 * @param cfg: config data.
121 * @param have_view_respip_cfg: set to true if any named view has respip
122 * configuration; otherwise set to false
123 * @return 1 on success, 0 on error.
125 int respip_views_apply_cfg(struct views* vs, struct config_file* cfg,
126 int* have_view_respip_cfg);
129 * Merge two replies to build a complete CNAME chain.
130 * It appends the content of 'tgt_rep' to 'base_rep', assuming (but not
131 * checking) the former ends with a CNAME and the latter resolves its target.
132 * A merged new reply will be built using 'region' and *new_repp will point
133 * to the new one on success.
134 * If the target reply would also be subject to a response-ip action for
135 * 'cinfo', this function uses 'base_rep' as the merged reply, ignoring
136 * 'tgt_rep'. This is for avoiding cases like a CNAME loop or failure of
137 * applying an action to an address.
138 * RRSIGs in 'tgt_rep' will be excluded in the merged reply, as the resulting
139 * reply is assumed to be faked due to a response-ip action and can't be
140 * considered secure in terms of DNSSEC.
141 * The caller must ensure that neither 'base_rep' nor 'tgt_rep' can be modified
142 * until this function returns.
143 * @param base_rep: the reply info containing an incomplete CNAME.
144 * @param qinfo: query info corresponding to 'base_rep'.
145 * @param tgt_rep: the reply info that completes the CNAME chain.
146 * @param cinfo: client info corresponding to 'base_rep'.
147 * @param must_validate: whether 'tgt_rep' must be DNSSEC-validated.
148 * @param new_repp: pointer placeholder for the merged reply. will be intact
150 * @param region: allocator to build *new_repp.
151 * @param az: auth zones containing RPZ information.
152 * @return 1 on success, 0 on error.
154 int respip_merge_cname(struct reply_info* base_rep,
155 const struct query_info* qinfo, const struct reply_info* tgt_rep,
156 const struct respip_client_info* cinfo, int must_validate,
157 struct reply_info** new_repp, struct regional* region,
158 struct auth_zones* az);
161 * See if any IP-based action should apply to any IP address of AAAA/A answer
162 * record in the reply. If so, apply the action. In some cases it rewrites
163 * the reply rrsets, in which case *new_repp will point to the updated reply
164 * info. Depending on the action, some of the rrsets in 'rep' will be
165 * shallow-copied into '*new_repp'; the caller must ensure that the rrsets
166 * in 'rep' are valid throughout the lifetime of *new_repp, and it must
167 * provide appropriate mutex if the rrsets can be shared by multiple threads.
168 * @param qinfo: query info corresponding to the reply.
169 * @param cinfo: client-specific info to identify the best matching action.
171 * @param rep: original reply info. must not be NULL.
172 * @param new_repp: can be set to the rewritten reply info (intact on failure).
173 * @param actinfo: result of response-ip processing
174 * @param alias_rrset: must not be NULL.
175 * @param search_only: if true, only check if an action would apply. actionp
176 * will be set (or intact) accordingly but the modified reply won't be built.
177 * @param az: auth zones containing RPZ information.
178 * @param region: allocator to build *new_repp.
179 * @return 1 on success, 0 on error.
181 int respip_rewrite_reply(const struct query_info* qinfo,
182 const struct respip_client_info* cinfo,
183 const struct reply_info *rep, struct reply_info** new_repp,
184 struct respip_action_info* actinfo,
185 struct ub_packed_rrset_key** alias_rrset,
186 int search_only, struct regional* region, struct auth_zones* az);
189 * Get the response-ip function block.
190 * @return: function block with function pointers to response-ip methods.
192 struct module_func_block* respip_get_funcblock(void);
194 /** response-ip init */
195 int respip_init(struct module_env* env, int id);
197 /** response-ip deinit */
198 void respip_deinit(struct module_env* env, int id);
200 /** response-ip operate on a query */
201 void respip_operate(struct module_qstate* qstate, enum module_ev event, int id,
202 struct outbound_entry* outbound);
204 /** inform response-ip super */
205 void respip_inform_super(struct module_qstate* qstate, int id,
206 struct module_qstate* super);
208 /** response-ip cleanup query state */
209 void respip_clear(struct module_qstate* qstate, int id);
212 * returns address of the IP address tree of the specified respip set;
213 * returns NULL for NULL input; exists for test purposes only
215 struct rbtree_type* respip_set_get_tree(struct respip_set* set);
218 * returns respip action for the specified node in the respip address
219 * returns respip_none for NULL input; exists for test purposes only
221 enum respip_action resp_addr_get_action(const struct resp_addr* addr);
224 * returns rrset portion of the specified node in the respip address
225 * tree; returns NULL for NULL input; exists for test purposes only
227 struct ub_packed_rrset_key* resp_addr_get_rrset(struct resp_addr* addr);
229 /** response-ip alloc size routine */
230 size_t respip_get_mem(struct module_env* env, int id);
233 * respip set emptiness test
234 * @param set respip set to test
235 * @return 0 if the specified set exists (non-NULL) and is non-empty;
236 * otherwise returns 1
238 int respip_set_is_empty(const struct respip_set* set);
241 * print log information for a query subject to an inform or inform-deny
242 * response-ip action.
243 * @param respip_actinfo: response-ip information that causes the action
244 * @param qname: query name in the context, will be ignored if local_alias is
246 * @param qtype: query type, in host byte order.
247 * @param qclass: query class, in host byte order.
248 * @param local_alias: set to a local alias if the query matches an alias in
249 * a local zone. In this case its owner name will be considered the actual
251 * @param repinfo: reply info containing the client's source address and port.
253 void respip_inform_print(struct respip_action_info* respip_actinfo,
254 uint8_t* qname, uint16_t qtype, uint16_t qclass,
255 struct local_rrset* local_alias, struct comm_reply* repinfo);
258 * Find resp_addr in tree, create and add to tree if it does not exist.
259 * @param set: struct containing the tree and region to alloc new node on.
260 * should hold write lock.
261 * @param addr: address to look up.
262 * @param addrlen: length of addr.
263 * @param net: netblock to lookup.
264 * @param create: create node if it does not exist when 1.
265 * @param ipstr: human redable ip string, for logging.
266 * @return newly created of found node, not holding lock.
269 respip_sockaddr_find_or_create(struct respip_set* set, struct sockaddr_storage* addr,
270 socklen_t addrlen, int net, int create, const char* ipstr);
273 * Add RR to resp_addr's RRset. Create RRset if not existing.
274 * @param region: region to alloc RR(set).
275 * @param raddr: resp_addr containing RRset. Must hold write lock.
276 * @param rrtype: RR type.
277 * @param rrclass: RR class.
279 * @param rdata: RDATA.
280 * @param rdata_len: length of rdata.
281 * @param rrstr: RR as string, for logging
282 * @param netblockstr: netblock as string, for logging
286 respip_enter_rr(struct regional* region, struct resp_addr* raddr,
287 uint16_t rrtype, uint16_t rrclass, time_t ttl, uint8_t* rdata,
288 size_t rdata_len, const char* rrstr, const char* netblockstr);
291 * Delete resp_addr node from tree.
292 * @param set: struct containing tree. Must hold write lock.
293 * @param node: node to delete. Not locked.
296 respip_sockaddr_delete(struct respip_set* set, struct resp_addr* node);
297 #endif /* RESPIP_RESPIP_H */