summaryrefslogtreecommitdiffstats
path: root/lib/dns/include/dns/librpz.h
diff options
context:
space:
mode:
Diffstat (limited to 'lib/dns/include/dns/librpz.h')
-rw-r--r--lib/dns/include/dns/librpz.h945
1 files changed, 945 insertions, 0 deletions
diff --git a/lib/dns/include/dns/librpz.h b/lib/dns/include/dns/librpz.h
new file mode 100644
index 0000000..8fdbe16
--- /dev/null
+++ b/lib/dns/include/dns/librpz.h
@@ -0,0 +1,945 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*
+ * Define the interface from a DNS resolver to the Response Policy Zone
+ * library, librpz.
+ *
+ * This file should be included only the interface functions between the
+ * resolver and librpz to avoid name space pollution.
+ *
+ * Copyright (c) 2016-2017 Farsight Security, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * version 1.2.12
+ */
+
+#pragma once
+
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#include <arpa/nameser.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+
+/*
+ * Allow either ordinary or dlopen() linking.
+ */
+#ifdef LIBRPZ_INTERNAL
+#define LIBDEF(t, s) extern t s;
+#define LIBDEF_F(f) LIBDEF(librpz_##f##_t, librpz_##f)
+#else /* ifdef LIBRPZ_INTERNAL */
+#define LIBDEF(t, s)
+#define LIBDEF_F(f)
+#endif /* ifdef LIBRPZ_INTERNAL */
+
+/*
+ * Response Policy Zone triggers.
+ * Comparisons of trigger precedences require
+ * LIBRPZ_TRIG_CLIENT_IP < LIBRPZ_TRIG_QNAME < LIBRPZ_TRIG_IP
+ * < LIBRPZ_TRIG_NSDNAME < LIBRPZ_TRIG_NSIP}
+ */
+typedef enum {
+ LIBRPZ_TRIG_BAD = 0,
+ LIBRPZ_TRIG_CLIENT_IP = 1,
+ LIBRPZ_TRIG_QNAME = 2,
+ LIBRPZ_TRIG_IP = 3,
+ LIBRPZ_TRIG_NSDNAME = 4,
+ LIBRPZ_TRIG_NSIP = 5
+} librpz_trig_t;
+#define LIBRPZ_TRIG_SIZE 3 /* sizeof librpz_trig_t in bits */
+typedef uint8_t librpz_tbit_t; /* one bit for each of the TRIGS_NUM
+ * trigger types */
+
+/*
+ * Response Policy Zone Actions or policies
+ */
+typedef enum {
+ LIBRPZ_POLICY_UNDEFINED = 0, /* an empty entry or no decision yet */
+ LIBRPZ_POLICY_DELETED = 1, /* placeholder for a deleted policy */
+
+ LIBRPZ_POLICY_PASSTHRU = 2, /* 'passthru': do not rewrite */
+ LIBRPZ_POLICY_DROP = 3, /* 'drop': do not respond */
+ LIBRPZ_POLICY_TCP_ONLY = 4, /* 'tcp-only': answer UDP with TC=1 */
+ LIBRPZ_POLICY_NXDOMAIN = 5, /* 'nxdomain': answer with NXDOMAIN */
+ LIBRPZ_POLICY_NODATA = 6, /* 'nodata': answer with ANCOUNT=0 */
+ LIBRPZ_POLICY_RECORD = 7, /* rewrite with the policy's RR */
+
+ /* only in client configurations to override the zone */
+ LIBRPZ_POLICY_GIVEN, /* 'given': what policy record says */
+ LIBRPZ_POLICY_DISABLED, /* at most log */
+ LIBRPZ_POLICY_CNAME, /* answer with 'cname x' */
+} librpz_policy_t;
+#define LIBRPZ_POLICY_BITS 4
+
+/*
+ * Special policies that appear as targets of CNAMEs
+ * NXDOMAIN is signaled by a CNAME with a "." target.
+ * NODATA is signaled by a CNAME with a "*." target.
+ */
+#define LIBRPZ_RPZ_PREFIX "rpz-"
+#define LIBRPZ_RPZ_PASSTHRU LIBRPZ_RPZ_PREFIX "passthru"
+#define LIBRPZ_RPZ_DROP LIBRPZ_RPZ_PREFIX "drop"
+#define LIBRPZ_RPZ_TCP_ONLY LIBRPZ_RPZ_PREFIX "tcp-only"
+
+typedef uint16_t librpz_dznum_t; /* dnsrpzd zone # in [0,DZNUM_MAX] */
+typedef uint8_t librpz_cznum_t; /* client zone # in [0,CZNUM_MAX] */
+
+/*
+ * CIDR block
+ */
+typedef struct librpz_prefix {
+ union {
+ struct in_addr in;
+ struct in6_addr in6;
+ } addr;
+ uint8_t family;
+ uint8_t len;
+} librpz_prefix_t;
+
+/*
+ * A domain
+ */
+typedef uint8_t librpz_dsize_t;
+typedef struct librpz_domain {
+ librpz_dsize_t size; /* of only .d */
+ uint8_t d[0]; /* variable length wire format */
+} librpz_domain_t;
+
+/*
+ * A maximal domain buffer
+ */
+typedef struct librpz_domain_buf {
+ librpz_dsize_t size;
+ uint8_t d[NS_MAXCDNAME];
+} librpz_domain_buf_t;
+
+/*
+ * A resource record without the owner name.
+ * C compilers say that sizeof(librpz_rr_t)=12 instead of 10.
+ */
+typedef struct {
+ uint16_t type; /* network byte order */
+ uint16_t class; /* network byte order */
+ uint32_t ttl; /* network byte order */
+ uint16_t rdlength; /* network byte order */
+ uint8_t rdata[0]; /* variable length */
+} librpz_rr_t;
+
+/*
+ * The database file might be mapped with different starting addresses
+ * by concurrent clients (resolvers), and so all pointers are offsets.
+ */
+typedef uint32_t librpz_idx_t;
+#define LIBRPZ_IDX_NULL 0
+#define LIBRPZ_IDX_MIN 1
+#define LIBRPZ_IDX_BAD ((librpz_idx_t)-1)
+/**
+ * Partial decoded results of a set of RPZ queries for a single DNS response
+ * or iteration through the mapped file.
+ */
+typedef int16_t librpz_result_id_t;
+typedef struct librpz_result {
+ librpz_idx_t next_rr;
+ librpz_result_id_t hit_id; /* trigger ID from resolver */
+ librpz_policy_t zpolicy; /* policy from zone */
+ librpz_policy_t policy; /* adjusted by client configuration */
+ librpz_dznum_t dznum; /* dnsrpzd zone number */
+ librpz_cznum_t cznum; /* librpz client zone number */
+ librpz_trig_t trig : LIBRPZ_TRIG_SIZE;
+ bool log : 1; /* log rewrite given librpz_log_level
+ * */
+} librpz_result_t;
+
+/**
+ * librpz trace or log levels.
+ */
+typedef enum {
+ LIBRPZ_LOG_FATAL = 0, /* always print fatal errors */
+ LIBRPZ_LOG_ERROR = 1, /* errors have this level */
+ LIBRPZ_LOG_TRACE1 = 2, /* big events such as dnsrpzd starts */
+ LIBRPZ_LOG_TRACE2 = 3, /* smaller dnsrpzd zone transfers */
+ LIBRPZ_LOG_TRACE3 = 4, /* librpz hits */
+ LIBRPZ_LOG_TRACE4 = 5, /* librpz lookups */
+ LIBRPZ_LOG_INVALID = 999,
+} librpz_log_level_t;
+typedef librpz_log_level_t(librpz_log_level_val_t)(librpz_log_level_t level);
+LIBDEF_F(log_level_val)
+
+/**
+ * Logging function that can be supplied by the resolver.
+ * @param level is one of librpz_log_level_t
+ * @param ctx is for use by the resolver's logging system.
+ * NULL mean a context-free message.
+ */
+typedef void(librpz_log_fnc_t)(librpz_log_level_t level, void *ctx,
+ const char *buf);
+
+/**
+ * Point librpz logging functions to the resolver's choice.
+ */
+typedef void(librpz_set_log_t)(librpz_log_fnc_t *new_log, const char *prog_nm);
+LIBDEF_F(set_log)
+
+/**
+ * librpz error messages are put in these buffers.
+ * Use a structure instead of naked char* to let the compiler check the length.
+ * A function defined with "foo(char buf[120])" can be called with
+ * "char sbuf[2]; foo(sbuf)" and suffer a buffer overrun.
+ */
+typedef struct {
+ char c[120];
+} librpz_emsg_t;
+
+#ifdef LIBRPZ_HAVE_ATTR
+#define LIBRPZ_UNUSED __attribute__((unused))
+#define LIBRPZ_PF(f, l) __attribute__((format(printf, f, l)))
+#define LIBRPZ_NORET __attribute__((__noreturn__))
+#else /* ifdef LIBRPZ_HAVE_ATTR */
+#define LIBRPZ_UNUSED
+#define LIBRPZ_PF(f, l)
+#define LIBRPZ_NORET
+#endif /* ifdef LIBRPZ_HAVE_ATTR */
+
+typedef bool(librpz_parse_log_opt_t)(librpz_emsg_t *emsg, const char *arg);
+LIBDEF_F(parse_log_opt)
+
+typedef void(librpz_vpemsg_t)(librpz_emsg_t *emsg, const char *p, va_list args);
+LIBDEF_F(vpemsg)
+typedef void(librpz_pemsg_t)(librpz_emsg_t *emsg, const char *p, ...)
+ LIBRPZ_PF(2, 3);
+LIBDEF_F(pemsg)
+
+typedef void(librpz_vlog_t)(librpz_log_level_t level, void *ctx, const char *p,
+ va_list args);
+LIBDEF_F(vlog)
+typedef void(librpz_log_t)(librpz_log_level_t level, void *ctx, const char *p,
+ ...) LIBRPZ_PF(3, 4);
+LIBDEF_F(log)
+
+typedef void(librpz_fatal_t)(int ex_code, const char *p, ...) LIBRPZ_PF(2, 3);
+extern void
+librpz_fatal(int ex_code, const char *p, ...) LIBRPZ_PF(2, 3) LIBRPZ_NORET;
+
+typedef void(librpz_rpz_assert_t)(const char *file, unsigned line,
+ const char *p, ...) LIBRPZ_PF(3, 4);
+extern void
+librpz_rpz_assert(const char *file, unsigned line, const char *p, ...)
+ LIBRPZ_PF(3, 4) LIBRPZ_NORET;
+
+typedef void(librpz_rpz_vassert_t)(const char *file, uint line, const char *p,
+ va_list args);
+extern void
+librpz_rpz_vassert(const char *file, uint line, const char *p,
+ va_list args) LIBRPZ_NORET;
+
+/*
+ * As far as clients are concerned, all relative pointers or indexes in a
+ * version of the mapped file except trie node parent pointers remain valid
+ * forever. A client must release a version so that it can be garbage
+ * collected by the file system. When dnsrpzd needs to expand the file,
+ * it copies the old file to a new, larger file. Clients can continue
+ * using the old file.
+ *
+ * Versions can also appear in a single file. Old nodes and trie values
+ * within the file are not destroyed until all clients using the version
+ * that contained the old values release the version.
+ *
+ * A client is marked as using version by connecting to the daemon. It is
+ * marked as using all subsequent versions. A client releases all versions
+ * by closing the connection or a range of versions by updating is slot
+ * in the shared memory version table.
+ *
+ * As far as clients are concerned, there are the following possible librpz
+ * failures:
+ * - malloc() or other fatal internal librpz problems indicated by
+ * a failing return from a librpz function
+ * All operations will fail until client handle is destroyed and
+ * recreated with librpz_client_detach() and librpz_client_create().
+ * - corrupt database detected by librpz code, corrupt database detected
+ * by dnsrpzd, or disconnection from the daemon.
+ * Current operations will fail.
+ *
+ * Clients assume that the file has already been unlinked before
+ * the corrupt flag is set so that they do not race with the server
+ * over the corruption of a single file. A client that finds the
+ * corrupt set knows that dnsrpzd has already crashed with
+ * abort() and is restarting. The client can re-connect to dnsrpzd
+ * and retransmit its configuration, backing off as usual if anything
+ * goes wrong.
+ *
+ * Searches of the database by a client do not need locks against dnsrpzd or
+ * other clients, but a lock is used to protect changes to the connection
+ * by competing threads in the client. The client provides functions
+ * to serialize the concurrent use of any single client handle.
+ * Functions that do nothing are appropriate for applications that are
+ * not "threaded" or that do not share client handles among threads.
+ * Otherwise, functions must be provided to librpz_clientcreate().
+ * Something like the following works with pthreads:
+ *
+ * static void
+ * lock(void *mutex) { assert(pthread_mutex_lock(mutex) == 0); }
+ *
+ * static void
+ * unlock(void *mutex) { assert(pthread_mutex_unlock(mutex) == 0); }
+ *
+ * static void
+ * mutex_destroy(void *mutex) { assert(pthread_mutex_destroy(mutex) == 0); }
+ *
+ *
+ *
+ * At every instant, all of the data and pointers in the mapped file are valid.
+ * Changes to trie node or other data are always made so that it and
+ * all pointers in and to it remain valid for a time. Old versions are
+ * eventually discarded.
+ *
+ * Dnsrpzd periodically defines a new version by setting aside all changes
+ * made since the previous version was defined. Subsequent changes
+ * made (only!) by dnsrpzd will be part of the next version.
+ *
+ * To discard an old version, dnsrpzd must know that all clients have stopped
+ * using that version. Clients do that by using part of the mapped file
+ * to tell dnsrpzd the oldest version that each client is using.
+ * Dnsrpzd assigns each connecting client an entry in the cversions array
+ * in the mapped file. The client puts version numbers into that entry
+ * to signal to dnsrpzd which versions that can be discarded.
+ * Dnsrpzd is free, as far as that client is concerned, to discard all
+ * numerically smaller versions. A client can disclaim all versions with
+ * the version number VERSIONS_ALL or 0.
+ *
+ * The race between a client changing its entry and dnsrpzd discarding a
+ * version is resolved by allowing dnsrpzd to discard all versions
+ * smaller or equal to the client's version number. If dnsrpzd is in
+ * the midst of discarding or about to discard version N when the
+ * client asserts N, no harm is done. The client depends only on
+ * the consistency of version N+1.
+ *
+ * This version mechanism depends in part on not being exercised too frequently
+ * Version numbers are 32 bits long and dnsrpzd creates new versions
+ * at most once every 30 seconds.
+ */
+
+/*
+ * Lock functions for concurrent use of a single librpz_client_t client handle.
+ */
+typedef void(librpz_mutex_t)(void *mutex);
+
+/*
+ * List of connections to dnsrpzd daemons.
+ */
+typedef struct librpz_clist librpz_clist_t;
+
+/*
+ * Client's handle on dnsrpzd.
+ */
+typedef struct librpz_client librpz_client_t;
+
+/**
+ * Create the list of connections to the dnsrpzd daemon.
+ * @param[out] emsg: error message
+ * @param lock: start exclusive access to the client handle
+ * @param unlock: end exclusive access to the client handle
+ * @param mutex_destroy: release the lock
+ * @param mutex: pointer to the lock for the client handle
+ * @param log_ctx: NULL or resolver's context log messages
+ */
+typedef librpz_clist_t *(librpz_clist_create_t)(librpz_emsg_t *emsg,
+ librpz_mutex_t *lock,
+ librpz_mutex_t *unlock,
+ librpz_mutex_t *mutex_destroy,
+ void *mutex, void *log_ctx);
+LIBDEF_F(clist_create)
+
+/**
+ * Release the list of dnsrpzd connections.
+ */
+typedef void(librpz_clist_detach_t)(librpz_clist_t **clistp);
+LIBDEF_F(clist_detach)
+
+/**
+ * Create a librpz client handle.
+ * @param[out] emsg: error message
+ * @param clist: of dnsrpzd connections
+ * @param cstr: string of configuration settings separated by ';' or '\n'
+ * @param use_expired: true to not ignore expired zones
+ * @return client handle or NULL if the handle could not be created
+ */
+typedef librpz_client_t *(librpz_client_create_t)(librpz_emsg_t *emsg,
+ librpz_clist_t *clist,
+ const char *cstr,
+ bool use_expired);
+LIBDEF_F(client_create)
+
+/**
+ * Start (if necessary) dnsrpzd and connect to it.
+ * @param[out] emsg: error message
+ * @param client handle
+ * @param optional: true if it is ok if starting the daemon is not allowed
+ */
+typedef bool(librpz_connect_t)(librpz_emsg_t *emsg, librpz_client_t *client,
+ bool optional);
+LIBDEF_F(connect)
+
+/**
+ * Start to destroy a librpz client handle.
+ * It will not be destroyed until the last set of RPZ queries represented
+ * by a librpz_rsp_t ends.
+ * @param client handle to be released
+ * @return false on error
+ */
+typedef void(librpz_client_detach_t)(librpz_client_t **clientp);
+LIBDEF_F(client_detach)
+
+/**
+ * State for a set of RPZ queries for a single DNS response
+ * or for listing the database.
+ */
+typedef struct librpz_rsp librpz_rsp_t;
+
+/**
+ * Start a set of RPZ queries for a single DNS response.
+ * @param[out] emsg: error message for false return or *rspp=NULL
+ * @param[out] rspp created context or NULL
+ * @param[out] min_ns_dotsp: NULL or pointer to configured MIN-NS-DOTS value
+ * @param client state
+ * @param have_rd: RD=1 in the DNS request
+ * @param have_do: DO=1 in the DNS request
+ * @return false on error
+ */
+typedef bool(librpz_rsp_create_t)(librpz_emsg_t *emsg, librpz_rsp_t **rspp,
+ int *min_ns_dotsp, librpz_client_t *client,
+ bool have_rd, bool have_do);
+LIBDEF_F(rsp_create)
+
+/**
+ * Finish RPZ work for a DNS response.
+ */
+typedef void(librpz_rsp_detach_t)(librpz_rsp_t **rspp);
+LIBDEF_F(rsp_detach)
+
+/**
+ * Get the final, accumulated result of a set of RPZ queries.
+ * Yield LIBRPZ_POLICY_UNDEFINED if
+ * - there were no hits,
+ * - there was a dispositive hit, be we have not recursed and are required
+ * to recurse so that evil DNS authorities will not know we are using RPZ
+ * - we have a hit and have recursed, but later data such as NSIP could
+ * override
+ * @param[out] emsg
+ * @param[out] result describes the hit
+ * or result->policy=LIBRPZ_POLICY_UNDEFINED without a hit
+ * @param[out] result: current policy rewrite values
+ * @param recursed: recursion has now been done even if it was not done
+ * when the hit was found
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_result_t)(librpz_emsg_t *emsg, librpz_result_t *result,
+ bool recursed, const librpz_rsp_t *rsp);
+LIBDEF_F(rsp_result)
+
+/**
+ * Might looking for a trigger be worthwhile?
+ * @param trig: look for this type of trigger
+ * @param ipv6: true if trig is LIBRPZ_TRIG_CLIENT_IP, LIBRPZ_TRIG_IP,
+ * or LIBRPZ_TRIG_NSIP and the IP address is IPv6
+ * @return: true if looking could be worthwhile
+ */
+typedef bool(librpz_have_trig_t)(librpz_trig_t trig, bool ipv6,
+ const librpz_rsp_t *rsp);
+LIBDEF_F(have_trig)
+
+/**
+ * Might looking for NSDNAME and NSIP triggers be worthwhile?
+ * @return: true if looking could be worthwhile
+ */
+typedef bool(librpz_have_ns_trig_t)(const librpz_rsp_t *rsp);
+LIBDEF_F(have_ns_trig)
+
+/**
+ * Convert the found client IP trie key to a CIDR block
+ * @param[out] emsg
+ * @param[out] prefix trigger
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_clientip_prefix_t)(librpz_emsg_t *emsg,
+ librpz_prefix_t *prefix,
+ librpz_rsp_t *rsp);
+LIBDEF_F(rsp_clientip_prefix)
+
+/**
+ * Compute the owner name of the found or result trie key, usually to log it.
+ * An IP address key might be returned as 8.0.0.0.127.rpz-client-ip.
+ * example.com. might be a qname trigger. example.com.rpz-nsdname. could
+ * be an NSDNAME trigger.
+ * @param[out] emsg
+ * @param[out] owner domain
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_domain_t)(librpz_emsg_t *emsg,
+ librpz_domain_buf_t *owner,
+ librpz_rsp_t *rsp);
+LIBDEF_F(rsp_domain)
+
+/**
+ * Get the next RR of the LIBRPZ_POLICY_RECORD result after an initial use of
+ * librpz_rsp_result() or librpz_itr_node() or after a previous use of
+ * librpz_rsp_rr(). The RR is in uncompressed wire format including type,
+ * class, ttl and length in network byte order.
+ * @param[out] emsg
+ * @param[out] typep: optional host byte order record type or ns_t_invalid (0)
+ * @param[out] classp: class such as ns_c_in
+ * @param[out] ttlp: TTL
+ * @param[out] rrp: optional malloc() buffer containing the next RR or
+ * NULL after the last RR
+ * @param[out] result: current policy rewrite values
+ * @param qname: used construct a wildcard CNAME
+ * @param qname_size
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_rr_t)(librpz_emsg_t *emsg, uint16_t *typep,
+ uint16_t *classp, uint32_t *ttlp,
+ librpz_rr_t **rrp, librpz_result_t *result,
+ const uint8_t *qname, size_t qname_size,
+ librpz_rsp_t *rsp);
+LIBDEF_F(rsp_rr)
+
+/**
+ * Get the next RR of the LIBRPZ_POLICY_RECORD result.
+ * @param[out] emsg
+ * @param[out] ttlp: TTL
+ * @param[out] rrp: malloc() buffer with SOA RR without owner name
+ * @param[out] result: current policy rewrite values
+ * @param[out] origin: SOA owner name
+ * @param[out] origin_size
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_soa_t)(librpz_emsg_t *emsg, uint32_t *ttlp,
+ librpz_rr_t **rrp, librpz_domain_buf_t *origin,
+ librpz_result_t *result, librpz_rsp_t *rsp);
+LIBDEF_F(rsp_soa)
+
+/**
+ * Get the SOA serial number for a policy zone to compare with a known value
+ * to check whether a zone transfer is complete.
+ */
+typedef bool(librpz_soa_serial_t)(librpz_emsg_t *emsg, uint32_t *serialp,
+ const char *domain_nm, librpz_rsp_t *rsp);
+LIBDEF_F(soa_serial)
+
+/**
+ * Save the current policy checking state.
+ * @param[out] emsg
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_push_t)(librpz_emsg_t *emsg, librpz_rsp_t *rsp);
+LIBDEF_F(rsp_push)
+#define LIBRPZ_RSP_STACK_DEPTH 3
+
+/**
+ * Restore the previous policy checking state.
+ * @param[out] emsg
+ * @param[out] result: NULL or restored policy rewrite values
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_pop_t)(librpz_emsg_t *emsg, librpz_result_t *result,
+ librpz_rsp_t *rsp);
+LIBDEF_F(rsp_pop)
+
+/**
+ * Discard the most recently save policy checking state.
+ * @param[out] emsg
+ * @param[out] result: NULL or restored policy rewrite values
+ * @return false on error
+ */
+typedef bool(librpz_rsp_pop_discard_t)(librpz_emsg_t *emsg, librpz_rsp_t *rsp);
+LIBDEF_F(rsp_pop_discard)
+
+/**
+ * Disable a zone.
+ * @param[out] emsg
+ * @param znum
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_rsp_forget_zone_t)(librpz_emsg_t *emsg, librpz_cznum_t znum,
+ librpz_rsp_t *rsp);
+LIBDEF_F(rsp_forget_zone)
+
+/**
+ * Apply RPZ to an IP address.
+ * @param[out] emsg
+ * @param addr: address to check
+ * @param ipv6: true for 16 byte IPv6 instead of 4 byte IPv4
+ * @param trig LIBRPZ_TRIG_CLIENT_IP, LIBRPZ_TRIG_IP, or LIBRPZ_TRIG_NSIP
+ * @param hit_id: caller chosen
+ * @param recursed: recursion has been done
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_ck_ip_t)(librpz_emsg_t *emsg, const void *addr, uint family,
+ librpz_trig_t trig, librpz_result_id_t hit_id,
+ bool recursed, librpz_rsp_t *rsp);
+LIBDEF_F(ck_ip)
+
+/**
+ * Apply RPZ to a wire-format domain.
+ * @param[out] emsg
+ * @param domain in wire format
+ * @param domain_size
+ * @param trig LIBRPZ_TRIG_QNAME or LIBRPZ_TRIG_NSDNAME
+ * @param hit_id: caller chosen
+ * @param recursed: recursion has been done
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return false on error
+ */
+typedef bool(librpz_ck_domain_t)(librpz_emsg_t *emsg, const uint8_t *domain,
+ size_t domain_size, librpz_trig_t trig,
+ librpz_result_id_t hit_id, bool recursed,
+ librpz_rsp_t *rsp);
+LIBDEF_F(ck_domain)
+
+/**
+ * Ask dnsrpzd to refresh a zone.
+ * @param[out] emsg error message
+ * @param librpz_domain_t domain to refresh
+ * @param client context
+ * @return false after error
+ */
+typedef bool(librpz_zone_refresh_t)(librpz_emsg_t *emsg, const char *domain,
+ librpz_rsp_t *rsp);
+LIBDEF_F(zone_refresh)
+
+/**
+ * Get a string describing the database
+ * @param license: include the license
+ * @param cfiles: include the configuration file names
+ * @param listens: include the local notify IP addresses
+ * @param[out] emsg error message if the result is null
+ * @param client context
+ * @return malloc'ed string or NULL after error
+ */
+typedef char *(librpz_db_info_t)(librpz_emsg_t *emsg, bool license, bool cfiles,
+ bool listens, librpz_rsp_t *rsp);
+LIBDEF_F(db_info)
+
+/**
+ * Start a context for listing the nodes and/or zones in the mapped file
+ * @param[out] emsg: error message for false return or *rspp=NULL
+ * @param[out] rspp: created context or NULL
+ * @param client context
+ * @return false after error
+ */
+typedef bool(librpz_itr_start_t)(librpz_emsg_t *emsg, librpz_rsp_t **rspp,
+ librpz_client_t *client);
+LIBDEF_F(itr_start)
+
+/**
+ * Get mapped file memory allocation statistics.
+ * @param[out] emsg: error message
+ * @param rsp state from librpz_itr_start()
+ * @return malloc'ed string or NULL after error
+ */
+typedef char *(librpz_mf_stats_t)(librpz_emsg_t *emsg, librpz_rsp_t *rsp);
+LIBDEF_F(mf_stats)
+
+/**
+ * Get versions currently used by clients.
+ * @param[out] emsg: error message
+ * @param[in,out] rsp: state from librpz_itr_start()
+ * @return malloc'ed string or NULL after error
+ */
+typedef char *(librpz_vers_stats_t)(librpz_emsg_t *emsg, librpz_rsp_t *rsp);
+LIBDEF_F(vers_stats)
+
+/**
+ * Allocate a string describing the next zone or "" after the last zone.
+ * @param[out] emsg
+ * @param all_zones to list all instead of only requested zones
+ * @param[in,out] rsp state from librpz_rsp_start()
+ * @return malloc'ed string or NULL after error
+ */
+typedef char *(librpz_itr_zone_t)(librpz_emsg_t *emsg, bool all_zones,
+ librpz_rsp_t *rsp);
+LIBDEF_F(itr_zone)
+
+/**
+ * Describe the next trie node while dumping the database.
+ * @param[out] emsg
+ * @param[out] result describes node
+ * or result->policy=LIBRPZ_POLICY_UNDEFINED after the last node.
+ * @param all_zones to list all instead of only requested zones
+ * @param[in,out] rsp state from librpz_itr_start()
+ * @return: false on error
+ */
+typedef bool(librpz_itr_node_t)(librpz_emsg_t *emsg, librpz_result_t *result,
+ bool all_zones, librpz_rsp_t *rsp);
+LIBDEF_F(itr_node)
+
+/**
+ * RPZ policy to string with a backup buffer of POLICY2STR_SIZE size
+ */
+typedef const char *(librpz_policy2str_t)(librpz_policy_t policy, char *buf,
+ size_t buf_size);
+#define POLICY2STR_SIZE sizeof("policy xxxxxx")
+LIBDEF_F(policy2str)
+
+/**
+ * Trigger type to string.
+ */
+typedef const char *(librpz_trig2str_t)(librpz_trig_t trig);
+LIBDEF_F(trig2str)
+
+/**
+ * Convert a number of seconds to a zone file duration string
+ */
+typedef const char *(librpz_secs2str_t)(time_t secs, char *buf,
+ size_t buf_size);
+#define SECS2STR_SIZE sizeof("1234567w7d24h59m59s")
+LIBDEF_F(secs2str)
+
+/**
+ * Parse a duration with 's', 'm', 'h', 'd', and 'w' units.
+ */
+typedef bool(librpz_str2secs_t)(librpz_emsg_t *emsg, time_t *val,
+ const char *str0);
+LIBDEF_F(str2secs)
+
+/**
+ * Translate selected rtypes to strings
+ */
+typedef const char *(librpz_rtype2str_t)(uint type, char *buf, size_t buf_size);
+#define RTYPE2STR_SIZE sizeof("type xxxxx")
+LIBDEF_F(rtype2str)
+
+/**
+ * Local version of ns_name_ntop() for portability.
+ */
+typedef int(librpz_domain_ntop_t)(const u_char *src, char *dst, size_t dstsiz);
+LIBDEF_F(domain_ntop)
+
+/**
+ * Local version of ns_name_pton().
+ */
+typedef int(librpz_domain_pton2_t)(const char *src, u_char *dst, size_t dstsiz,
+ size_t *dstlen, bool lower);
+LIBDEF_F(domain_pton2)
+
+typedef union socku socku_t;
+typedef socku_t *(librpz_mk_inet_su_t)(socku_t *su, const struct in_addr *addrp,
+ in_port_t port);
+LIBDEF_F(mk_inet_su)
+
+typedef socku_t *(librpz_mk_inet6_su_t)(socku_t *su,
+ const struct in6_addr *addrp,
+ uint32_t scope_id, in_port_t port);
+LIBDEF_F(mk_inet6_su)
+
+typedef bool(librpz_str2su_t)(socku_t *sup, const char *str);
+LIBDEF_F(str2su)
+
+typedef char *(librpz_su2str_t)(char *str, size_t str_len, const socku_t *su);
+LIBDEF_F(su2str)
+#define SU2STR_SIZE (INET6_ADDRSTRLEN + 1 + 6 + 1)
+
+/**
+ * default path to dnsrpzd
+ */
+LIBDEF(const char *, librpz_dnsrpzd_path)
+
+#undef LIBDEF
+
+/*
+ * This is the dlopen() interface to librpz.
+ */
+typedef const struct {
+ const char *dnsrpzd_path;
+ const char *version;
+ librpz_parse_log_opt_t *parse_log_opt;
+ librpz_log_level_val_t *log_level_val;
+ librpz_set_log_t *set_log;
+ librpz_vpemsg_t *vpemsg;
+ librpz_pemsg_t *pemsg;
+ librpz_vlog_t *vlog;
+ librpz_log_t *log;
+ librpz_fatal_t *fatal LIBRPZ_NORET;
+ librpz_rpz_assert_t *rpz_assert LIBRPZ_NORET;
+ librpz_rpz_vassert_t *rpz_vassert LIBRPZ_NORET;
+ librpz_clist_create_t *clist_create;
+ librpz_clist_detach_t *clist_detach;
+ librpz_client_create_t *client_create;
+ librpz_connect_t *connect;
+ librpz_client_detach_t *client_detach;
+ librpz_rsp_create_t *rsp_create;
+ librpz_rsp_detach_t *rsp_detach;
+ librpz_rsp_result_t *rsp_result;
+ librpz_have_trig_t *have_trig;
+ librpz_have_ns_trig_t *have_ns_trig;
+ librpz_rsp_clientip_prefix_t *rsp_clientip_prefix;
+ librpz_rsp_domain_t *rsp_domain;
+ librpz_rsp_rr_t *rsp_rr;
+ librpz_rsp_soa_t *rsp_soa;
+ librpz_soa_serial_t *soa_serial;
+ librpz_rsp_push_t *rsp_push;
+ librpz_rsp_pop_t *rsp_pop;
+ librpz_rsp_pop_discard_t *rsp_pop_discard;
+ librpz_rsp_forget_zone_t *rsp_forget_zone;
+ librpz_ck_ip_t *ck_ip;
+ librpz_ck_domain_t *ck_domain;
+ librpz_zone_refresh_t *zone_refresh;
+ librpz_db_info_t *db_info;
+ librpz_itr_start_t *itr_start;
+ librpz_mf_stats_t *mf_stats;
+ librpz_vers_stats_t *vers_stats;
+ librpz_itr_zone_t *itr_zone;
+ librpz_itr_node_t *itr_node;
+ librpz_policy2str_t *policy2str;
+ librpz_trig2str_t *trig2str;
+ librpz_secs2str_t *secs2str;
+ librpz_str2secs_t *str2secs;
+ librpz_rtype2str_t *rtype2str;
+ librpz_domain_ntop_t *domain_ntop;
+ librpz_domain_pton2_t *domain_pton2;
+ librpz_mk_inet_su_t *mk_inet_su;
+ librpz_mk_inet6_su_t *mk_inet6_su;
+ librpz_str2su_t *str2su;
+ librpz_su2str_t *su2str;
+} librpz_0_t;
+extern librpz_0_t librpz_def_0;
+
+/*
+ * Future versions can be upward compatible by defining LIBRPZ_DEF as
+ * librpz_X_t.
+ */
+#define LIBRPZ_DEF librpz_def_0
+#define LIBRPZ_DEF_STR "librpz_def_0"
+
+typedef librpz_0_t librpz_t;
+extern librpz_t *librpz;
+
+#if LIBRPZ_LIB_OPEN == 2
+#include <dlfcn.h>
+
+/**
+ * link-load librpz
+ * @param[out] emsg: error message
+ * @param[in,out] dl_handle: NULL or pointer to new dlopen handle
+ * @param[in] path: librpz.so path
+ * @return address of interface structure or NULL on failure
+ */
+static inline librpz_t *
+librpz_lib_open(librpz_emsg_t *emsg, void **dl_handle, const char *path) {
+ void *handle;
+ librpz_t *new_librpz;
+
+ emsg->c[0] = '\0';
+
+ /*
+ * Close a previously opened handle on librpz.so.
+ */
+ if (dl_handle != NULL && *dl_handle != NULL) {
+ if (dlclose(*dl_handle) != 0) {
+ snprintf(emsg->c, sizeof(librpz_emsg_t),
+ "dlopen(NULL): %s", dlerror());
+ return (NULL);
+ }
+ *dl_handle = NULL;
+ }
+
+ /*
+ * First try the main executable of the process in case it was
+ * linked to librpz.
+ * Do not worry if we cannot search the main executable of the process.
+ */
+ handle = dlopen(NULL, RTLD_NOW | RTLD_LOCAL);
+ if (handle != NULL) {
+ new_librpz = dlsym(handle, LIBRPZ_DEF_STR);
+ if (new_librpz != NULL) {
+ if (dl_handle != NULL) {
+ *dl_handle = handle;
+ }
+ return (new_librpz);
+ }
+ if (dlclose(handle) != 0) {
+ snprintf(emsg->c, sizeof(librpz_emsg_t),
+ "dlsym(NULL, " LIBRPZ_DEF_STR "): %s",
+ dlerror());
+ return (NULL);
+ }
+ }
+
+ if (path == NULL || path[0] == '\0') {
+ snprintf(emsg->c, sizeof(librpz_emsg_t),
+ "librpz not linked and no dlopen() path provided");
+ return (NULL);
+ }
+
+ handle = dlopen(path, RTLD_NOW | RTLD_LOCAL);
+ if (handle == NULL) {
+ snprintf(emsg->c, sizeof(librpz_emsg_t), "dlopen(%s): %s", path,
+ dlerror());
+ return (NULL);
+ }
+ new_librpz = dlsym(handle, LIBRPZ_DEF_STR);
+ if (new_librpz != NULL) {
+ if (dl_handle != NULL) {
+ *dl_handle = handle;
+ }
+ return (new_librpz);
+ }
+ snprintf(emsg->c, sizeof(librpz_emsg_t),
+ "dlsym(%s, " LIBRPZ_DEF_STR "): %s", path, dlerror());
+ dlclose(handle);
+ return (NULL);
+}
+#elif defined(LIBRPZ_LIB_OPEN)
+/*
+ * Statically link to the librpz.so DSO on systems without dlopen()
+ */
+static inline librpz_t *
+librpz_lib_open(librpz_emsg_t *emsg, void **dl_handle, const char *path) {
+ (void)(path);
+
+ if (dl_handle != NULL) {
+ *dl_handle = NULL;
+ }
+
+#if LIBRPZ_LIB_OPEN == 1
+ emsg->c[0] = '\0';
+ return (&LIBRPZ_DEF);
+#else /* if LIBRPZ_LIB_OPEN == 1 */
+ snprintf(emsg->c, sizeof(librpz_emsg_t),
+ "librpz not available via ./configure");
+ return (NULL);
+#endif /* LIBRPZ_LIB_OPEN */
+}
+#endif /* LIBRPZ_LIB_OPEN */