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- /*
- * Copyright (c) 2013-2014, Vsevolod Stakhov
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY AUTHOR ''AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
- #ifndef RDNS_H
- #define RDNS_H
-
- #include <sys/types.h>
- #include <stddef.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <stdarg.h>
- #include <netinet/in.h>
- #include <arpa/inet.h>
-
- #ifdef __cplusplus
- extern "C" {
- #endif
-
- struct rdns_reply;
- struct rdns_request;
- struct rdns_io_channel;
-
- typedef void (*dns_callback_type) (struct rdns_reply *reply, void *arg);
-
- enum rdns_request_type {
- RDNS_REQUEST_INVALID = -1,
- RDNS_REQUEST_A = 1,
- RDNS_REQUEST_NS = 2,
- RDNS_REQUEST_CNAME = 5,
- RDNS_REQUEST_SOA = 6,
- RDNS_REQUEST_PTR = 12,
- RDNS_REQUEST_MX = 15,
- RDNS_REQUEST_TXT = 16,
- RDNS_REQUEST_SRV = 33,
- RDNS_REQUEST_SPF = 99,
- RDNS_REQUEST_AAAA = 28,
- RDNS_REQUEST_TLSA = 52,
- RDNS_REQUEST_ANY = 255
- };
-
- union rdns_reply_element_un {
- struct {
- struct in_addr addr;
- } a;
- struct {
- struct in6_addr addr;
- } aaa;
- struct {
- char *name;
- } ptr;
- struct {
- char *name;
- } ns;
- struct {
- char *name;
- uint16_t priority;
- } mx;
- struct {
- char *data;
- } txt;
- struct {
- uint16_t priority;
- uint16_t weight;
- uint16_t port;
- char *target;
- } srv;
- struct {
- char *mname;
- char *admin;
- uint32_t serial;
- int32_t refresh;
- int32_t retry;
- int32_t expire;
- uint32_t minimum;
- } soa;
- struct {
- uint8_t usage;
- uint8_t selector;
- uint8_t match_type;
- uint16_t datalen;
- uint8_t *data;
- } tlsa;
- struct {
- char *name;
- } cname;
- };
-
- struct rdns_reply_entry {
- union rdns_reply_element_un content;
- enum rdns_request_type type;
- int32_t ttl;
- struct rdns_reply_entry *prev, *next;
- };
-
-
- enum dns_rcode {
- RDNS_RC_INVALID = -1,
- RDNS_RC_NOERROR = 0,
- RDNS_RC_FORMERR = 1,
- RDNS_RC_SERVFAIL = 2,
- RDNS_RC_NXDOMAIN = 3,
- RDNS_RC_NOTIMP = 4,
- RDNS_RC_REFUSED = 5,
- RDNS_RC_YXDOMAIN = 6,
- RDNS_RC_YXRRSET = 7,
- RDNS_RC_NXRRSET = 8,
- RDNS_RC_NOTAUTH = 9,
- RDNS_RC_NOTZONE = 10,
- RDNS_RC_TIMEOUT = 11,
- RDNS_RC_NETERR = 12,
- RDNS_RC_NOREC = 13
- };
-
- enum dns_reply_flags {
- RDNS_AUTH = (1u << 0u),
- RDNS_TRUNCATED = (1u << 1u)
- };
-
- struct rdns_reply {
- struct rdns_request *request;
- struct rdns_resolver *resolver;
- struct rdns_reply_entry *entries;
- const char *requested_name;
- enum dns_rcode code;
- uint8_t flags; /* see enum dns_reply_flags */
- };
-
- typedef void (*rdns_periodic_callback)(void *user_data);
-
- struct rdns_async_context {
- void *data;
- void* (*add_read)(void *priv_data, int fd, void *user_data);
- void (*del_read)(void *priv_data, void *ev_data);
- void* (*add_write)(void *priv_data, int fd, void *user_data);
- void (*del_write)(void *priv_data, void *ev_data);
- void* (*add_timer)(void *priv_data, double after, void *user_data);
- void (*repeat_timer)(void *priv_data, void *ev_data);
- void (*del_timer)(void *priv_data, void *ev_data);
- void* (*add_periodic)(void *priv_data, double after,
- rdns_periodic_callback cb, void *user_data);
- void (*del_periodic)(void *priv_data, void *ev_data);
- void (*cleanup)(void *priv_data);
- };
-
- struct rdns_upstream_elt {
- void *server;
- void *lib_data;
- };
-
- struct rdns_upstream_context {
- void *data;
- struct rdns_upstream_elt* (*select)(const char *name,
- size_t len, void *ups_data);
- struct rdns_upstream_elt* (*select_retransmit)(const char *name, size_t len,
- struct rdns_upstream_elt* prev_elt,
- void *ups_data);
- unsigned int (*count)(void *ups_data);
- void (*ok)(struct rdns_upstream_elt *elt, void *ups_data);
- void (*fail)(struct rdns_upstream_elt *elt, void *ups_data, const char *reason);
- };
-
- /**
- * Type of rdns plugin
- */
- enum rdns_plugin_type {
- RDNS_PLUGIN_CURVE = 0
- };
-
- typedef ssize_t (*rdns_network_send_callback) (struct rdns_request *req, void *plugin_data,
- struct sockaddr *saddr, socklen_t slen);
- typedef ssize_t (*rdns_network_recv_callback) (struct rdns_io_channel *ioc, void *buf,
- size_t len, void *plugin_data,
- struct rdns_request **req_out,
- struct sockaddr *saddr, socklen_t slen);
- typedef void (*rdns_network_finish_callback) (struct rdns_request *req, void *plugin_data);
- typedef void (*rdns_plugin_dtor_callback) (struct rdns_resolver *resolver, void *plugin_data);
-
- struct rdns_plugin {
- enum rdns_plugin_type type;
- union {
- struct {
- rdns_network_send_callback send_cb;
- rdns_network_recv_callback recv_cb;
- rdns_network_finish_callback finish_cb;
- } curve_plugin;
- } cb;
- rdns_plugin_dtor_callback dtor;
- void *data;
- };
-
- /*
- * RDNS logger types
- */
- /*
- * These types are somehow compatible with glib
- */
- enum rdns_log_level {
- RDNS_LOG_ERROR = 1 << 3,
- RDNS_LOG_WARNING = 1 << 4,
- RDNS_LOG_INFO = 1 << 6,
- RDNS_LOG_DEBUG = 1 << 7
- };
- typedef void (*rdns_log_function) (
- void *log_data, //!< opaque data pointer
- enum rdns_log_level level, //!< level of message
- const char *function, //!< calling function
- const char *format, //!< format
- va_list args //!< set of arguments
- );
-
- struct rdns_request_name {
- char *name;
- enum rdns_request_type type;
- unsigned int len;
- };
-
- #define MAX_FAKE_NAME 1000
-
- /*
- * RDNS API
- */
-
- enum rdns_resolver_flags {
- RDNS_RESOLVER_DEFAULT,
- RDNS_RESOLVER_NOIDN = (1u << 0u),
- };
-
- /**
- * Create DNS resolver structure
- */
- struct rdns_resolver *rdns_resolver_new (int flags);
-
- /**
- * Bind resolver to specified async context
- * @param ctx
- */
- void rdns_resolver_async_bind (struct rdns_resolver *resolver,
- struct rdns_async_context *ctx);
-
- /**
- * Enable stub dnssec resolver
- * @param resolver
- */
- void rdns_resolver_set_dnssec (struct rdns_resolver *resolver, bool enabled);
-
- /**
- * Add new DNS server definition to the resolver
- * @param resolver resolver object
- * @param name name of DNS server (should be ipv4 or ipv6 address)
- * @param priority priority (can be 0 for fair round-robin)
- * @param io_cnt a number of sockets that are simultaneously opened to this server
- * @return opaque pointer that could be used to select upstream
- */
- void* rdns_resolver_add_server (struct rdns_resolver *resolver,
- const char *name, unsigned int port,
- int priority, unsigned int io_cnt);
-
-
- /**
- * Load nameservers definition from resolv.conf file
- * @param resolver resolver object
- * @param path path to resolv.conf file (/etc/resolv.conf typically)
- * @return true if resolv.conf has been parsed
- */
- bool rdns_resolver_parse_resolv_conf (struct rdns_resolver *resolver,
- const char *path);
-
- typedef bool (*rdns_resolv_conf_cb) (struct rdns_resolver *resolver,
- const char *name, unsigned int port,
- int priority, unsigned int io_cnt, void *ud);
- /**
- * Parse nameservers calling the specified callback for each nameserver
- * @param resolve resolver object
- * @param path path to resolv.conf file (/etc/resolv.conf typically)
- * @param cb callback to call
- * @param ud userdata for callback
- * @return true if resolv.conf has been parsed
- */
- bool rdns_resolver_parse_resolv_conf_cb (struct rdns_resolver *resolver,
- const char *path, rdns_resolv_conf_cb cb, void *ud);
-
- /**
- * Set an external logger function to log messages from the resolver
- * @param resolver resolver object
- * @param logger logger callback
- * @param log_data opaque data
- */
- void rdns_resolver_set_logger (struct rdns_resolver *resolver,
- rdns_log_function logger, void *log_data);
-
- /**
- * Set log level for an internal logger (stderr one)
- * @param resolver resolver object
- * @param level desired log level
- */
- void rdns_resolver_set_log_level (struct rdns_resolver *resolver,
- enum rdns_log_level level);
-
- /**
- * Set upstream library for selecting DNS upstreams
- * @param resolver resolver object
- * @param ups_ctx upstream functions
- * @param ups_data opaque data
- */
- void rdns_resolver_set_upstream_lib (struct rdns_resolver *resolver,
- struct rdns_upstream_context *ups_ctx,
- void *ups_data);
-
- /**
- * Set maximum number of dns requests to be sent to a socket to be refreshed
- * @param resolver resolver object
- * @param max_ioc_uses unsigned count of socket usage limit
- * @param check_time specifies how often to check for sockets and refresh them
- */
- void rdns_resolver_set_max_io_uses (struct rdns_resolver *resolver,
- uint64_t max_ioc_uses, double check_time);
-
- /**
- * Register new plugin for rdns resolver
- * @param resolver
- * @param plugin
- */
- void rdns_resolver_register_plugin (struct rdns_resolver *resolver,
- struct rdns_plugin *plugin);
-
- /**
- * Add a fake reply for a specified name
- * @param resolver
- * @param type
- * @param name (must not be larger than MAX_FAKE_NAME)
- * @param reply
- */
- void rdns_resolver_set_fake_reply (struct rdns_resolver *resolver,
- const char *name,
- enum rdns_request_type type,
- enum dns_rcode rcode,
- struct rdns_reply_entry *reply);
-
- /**
- * Init DNS resolver
- * @param resolver
- * @return
- */
- bool rdns_resolver_init (struct rdns_resolver *resolver);
-
- /**
- * Decrease refcount for a resolver and free it if refcount is 0
- * @param resolver
- */
- void rdns_resolver_release (struct rdns_resolver *resolver);
-
- /**
- * Make a DNS request
- * @param resolver resolver object
- * @param cb callback to call on resolve completing
- * @param ud user data for callback
- * @param timeout timeout in seconds
- * @param repeats how much time to retransmit query
- * @param queries how much RR queries to send
- * @param ... -> queries in format: <query_type>[,type_argument[,type_argument...]]
- * @return opaque request object or NULL
- */
- struct rdns_request* rdns_make_request_full (
- struct rdns_resolver *resolver,
- dns_callback_type cb,
- void *cbdata,
- double timeout,
- unsigned int repeats,
- unsigned int queries,
- ...
- );
-
- /**
- * Get textual presentation of DNS error code
- */
- const char *rdns_strerror (enum dns_rcode rcode);
-
- /**
- * Get textual presentation of DNS request type
- */
- const char *rdns_strtype (enum rdns_request_type type);
-
- /**
- * Parse string and return request type
- * @param str
- * @return
- */
- enum rdns_request_type rdns_type_fromstr (const char *str);
-
- /**
- * Returns string representing request type
- * @param rcode
- * @return
- */
- const char *
- rdns_str_from_type (enum rdns_request_type rcode);
-
- /**
- * Parse string and return error code
- * @param str
- * @return
- */
- enum dns_rcode rdns_rcode_fromstr (const char *str);
-
- /**
- * Increase refcount for a request
- * @param req
- * @return
- */
- struct rdns_request* rdns_request_retain (struct rdns_request *req);
-
- /**
- * Decrease refcount for a request and free it if refcount is 0
- * @param req
- */
- void rdns_request_release (struct rdns_request *req);
-
- /**
- * Check whether a request contains `type` request
- * @param req request object
- * @param type check for a specified type
- * @return true if `type` has been requested
- */
- bool rdns_request_has_type (struct rdns_request *req, enum rdns_request_type type);
-
- /**
- * Return requested name for a request
- * @param req request object
- * @return requested name as it was passed to `rdns_make_request`
- */
- const struct rdns_request_name* rdns_request_get_name (struct rdns_request *req,
- unsigned int *count);
-
- /**
- * Return a DNS server name associated with the request
- * @param req request object
- * @return name of a DNS server
- */
- const char* rdns_request_get_server (struct rdns_request *req);
-
-
- /**
- * Return PTR string for a request (ipv4 or ipv6) addresses
- * @param str string representation of IP address
- * @return name to resolve or NULL if `str` is not an IP address; caller must free result when it is unused
- */
- char * rdns_generate_ptr_from_str (const char *str);
-
- /**
- * Format DNS name of the packet punycoding if needed
- * @param req request
- * @param name name string
- * @param namelen length of name
- */
- bool rdns_format_dns_name (struct rdns_resolver *resolver,
- const char *name, size_t namelen,
- char **out, size_t *outlen);
-
- /*
- * Private functions used by async libraries as callbacks
- */
-
- void rdns_process_read (int fd, void *arg);
- void rdns_process_timer (void *arg);
- void rdns_process_write (int fd, void *arg);
-
- #ifdef __cplusplus
- }
- #endif
-
- #endif
|