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Diffstat (limited to 'libs/libevent/include/event2/dns.h')
| -rw-r--r-- | libs/libevent/include/event2/dns.h | 717 |
1 files changed, 0 insertions, 717 deletions
diff --git a/libs/libevent/include/event2/dns.h b/libs/libevent/include/event2/dns.h deleted file mode 100644 index 17cd86a2ec..0000000000 --- a/libs/libevent/include/event2/dns.h +++ /dev/null @@ -1,717 +0,0 @@ -/* - * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu> - * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. 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. - * 3. The name of the author may not be used to endorse or promote products - * derived from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE 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 THE 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. - */ - -/* - * The original DNS code is due to Adam Langley with heavy - * modifications by Nick Mathewson. Adam put his DNS software in the - * public domain. You can find his original copyright below. Please, - * aware that the code as part of Libevent is governed by the 3-clause - * BSD license above. - * - * This software is Public Domain. To view a copy of the public domain dedication, - * visit http://creativecommons.org/licenses/publicdomain/ or send a letter to - * Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA. - * - * I ask and expect, but do not require, that all derivative works contain an - * attribution similar to: - * Parts developed by Adam Langley <agl@imperialviolet.org> - * - * You may wish to replace the word "Parts" with something else depending on - * the amount of original code. - * - * (Derivative works does not include programs which link against, run or include - * the source verbatim in their source distributions) - */ - -/** @file event2/dns.h - * - * Welcome, gentle reader - * - * Async DNS lookups are really a whole lot harder than they should be, - * mostly stemming from the fact that the libc resolver has never been - * very good at them. Before you use this library you should see if libc - * can do the job for you with the modern async call getaddrinfo_a - * (see http://www.imperialviolet.org/page25.html#e498). Otherwise, - * please continue. - * - * The library keeps track of the state of nameservers and will avoid - * them when they go down. Otherwise it will round robin between them. - * - * Quick start guide: - * #include "evdns.h" - * void callback(int result, char type, int count, int ttl, - * void *addresses, void *arg); - * evdns_resolv_conf_parse(DNS_OPTIONS_ALL, "/etc/resolv.conf"); - * evdns_resolve("www.hostname.com", 0, callback, NULL); - * - * When the lookup is complete the callback function is called. The - * first argument will be one of the DNS_ERR_* defines in evdns.h. - * Hopefully it will be DNS_ERR_NONE, in which case type will be - * DNS_IPv4_A, count will be the number of IP addresses, ttl is the time - * which the data can be cached for (in seconds), addresses will point - * to an array of uint32_t's and arg will be whatever you passed to - * evdns_resolve. - * - * Searching: - * - * In order for this library to be a good replacement for glibc's resolver it - * supports searching. This involves setting a list of default domains, in - * which names will be queried for. The number of dots in the query name - * determines the order in which this list is used. - * - * Searching appears to be a single lookup from the point of view of the API, - * although many DNS queries may be generated from a single call to - * evdns_resolve. Searching can also drastically slow down the resolution - * of names. - * - * To disable searching: - * 1. Never set it up. If you never call evdns_resolv_conf_parse or - * evdns_search_add then no searching will occur. - * - * 2. If you do call evdns_resolv_conf_parse then don't pass - * DNS_OPTION_SEARCH (or DNS_OPTIONS_ALL, which implies it). - * - * 3. When calling evdns_resolve, pass the DNS_QUERY_NO_SEARCH flag. - * - * The order of searches depends on the number of dots in the name. If the - * number is greater than the ndots setting then the names is first tried - * globally. Otherwise each search domain is appended in turn. - * - * The ndots setting can either be set from a resolv.conf, or by calling - * evdns_search_ndots_set. - * - * For example, with ndots set to 1 (the default) and a search domain list of - * ["myhome.net"]: - * Query: www - * Order: www.myhome.net, www. - * - * Query: www.abc - * Order: www.abc., www.abc.myhome.net - * - * Internals: - * - * Requests are kept in two queues. The first is the inflight queue. In - * this queue requests have an allocated transaction id and nameserver. - * They will soon be transmitted if they haven't already been. - * - * The second is the waiting queue. The size of the inflight ring is - * limited and all other requests wait in waiting queue for space. This - * bounds the number of concurrent requests so that we don't flood the - * nameserver. Several algorithms require a full walk of the inflight - * queue and so bounding its size keeps thing going nicely under huge - * (many thousands of requests) loads. - * - * If a nameserver loses too many requests it is considered down and we - * try not to use it. After a while we send a probe to that nameserver - * (a lookup for google.com) and, if it replies, we consider it working - * again. If the nameserver fails a probe we wait longer to try again - * with the next probe. - */ - -#ifndef EVENT2_DNS_H_INCLUDED_ -#define EVENT2_DNS_H_INCLUDED_ - -#include <event2/visibility.h> - -#ifdef __cplusplus -extern "C" { -#endif - -/* For integer types. */ -#include <event2/util.h> - -/** Error codes 0-5 are as described in RFC 1035. */ -#define DNS_ERR_NONE 0 -/** The name server was unable to interpret the query */ -#define DNS_ERR_FORMAT 1 -/** The name server was unable to process this query due to a problem with the - * name server */ -#define DNS_ERR_SERVERFAILED 2 -/** The domain name does not exist */ -#define DNS_ERR_NOTEXIST 3 -/** The name server does not support the requested kind of query */ -#define DNS_ERR_NOTIMPL 4 -/** The name server refuses to reform the specified operation for policy - * reasons */ -#define DNS_ERR_REFUSED 5 -/** The reply was truncated or ill-formatted */ -#define DNS_ERR_TRUNCATED 65 -/** An unknown error occurred */ -#define DNS_ERR_UNKNOWN 66 -/** Communication with the server timed out */ -#define DNS_ERR_TIMEOUT 67 -/** The request was canceled because the DNS subsystem was shut down. */ -#define DNS_ERR_SHUTDOWN 68 -/** The request was canceled via a call to evdns_cancel_request */ -#define DNS_ERR_CANCEL 69 -/** There were no answers and no error condition in the DNS packet. - * This can happen when you ask for an address that exists, but a record - * type that doesn't. */ -#define DNS_ERR_NODATA 70 - -#define DNS_IPv4_A 1 -#define DNS_PTR 2 -#define DNS_IPv6_AAAA 3 - -#define DNS_QUERY_NO_SEARCH 1 - -#define DNS_OPTION_SEARCH 1 -#define DNS_OPTION_NAMESERVERS 2 -#define DNS_OPTION_MISC 4 -#define DNS_OPTION_HOSTSFILE 8 -#define DNS_OPTIONS_ALL 15 - -/* Obsolete name for DNS_QUERY_NO_SEARCH */ -#define DNS_NO_SEARCH DNS_QUERY_NO_SEARCH - -/** - * The callback that contains the results from a lookup. - * - result is one of the DNS_ERR_* values (DNS_ERR_NONE for success) - * - type is either DNS_IPv4_A or DNS_PTR or DNS_IPv6_AAAA - * - count contains the number of addresses of form type - * - ttl is the number of seconds the resolution may be cached for. - * - addresses needs to be cast according to type. It will be an array of - * 4-byte sequences for ipv4, or an array of 16-byte sequences for ipv6, - * or a nul-terminated string for PTR. - */ -typedef void (*evdns_callback_type) (int result, char type, int count, int ttl, void *addresses, void *arg); - -struct evdns_base; -struct event_base; - -/** Flag for evdns_base_new: process resolv.conf. */ -#define EVDNS_BASE_INITIALIZE_NAMESERVERS 1 -/** Flag for evdns_base_new: Do not prevent the libevent event loop from - * exiting when we have no active dns requests. */ -#define EVDNS_BASE_DISABLE_WHEN_INACTIVE 0x8000 - -/** - Initialize the asynchronous DNS library. - - This function initializes support for non-blocking name resolution by - calling evdns_resolv_conf_parse() on UNIX and - evdns_config_windows_nameservers() on Windows. - - @param event_base the event base to associate the dns client with - @param flags any of EVDNS_BASE_INITIALIZE_NAMESERVERS| - EVDNS_BASE_DISABLE_WHEN_INACTIVE - @return evdns_base object if successful, or NULL if an error occurred. - @see evdns_base_free() - */ -EVENT2_EXPORT_SYMBOL -struct evdns_base * evdns_base_new(struct event_base *event_base, int initialize_nameservers); - - -/** - Shut down the asynchronous DNS resolver and terminate all active requests. - - If the 'fail_requests' option is enabled, all active requests will return - an empty result with the error flag set to DNS_ERR_SHUTDOWN. Otherwise, - the requests will be silently discarded. - - @param evdns_base the evdns base to free - @param fail_requests if zero, active requests will be aborted; if non-zero, - active requests will return DNS_ERR_SHUTDOWN. - @see evdns_base_new() - */ -EVENT2_EXPORT_SYMBOL -void evdns_base_free(struct evdns_base *base, int fail_requests); - -/** - Remove all hosts entries that have been loaded into the event_base via - evdns_base_load_hosts or via event_base_resolv_conf_parse. - - @param evdns_base the evdns base to remove outdated host addresses from - */ -EVENT2_EXPORT_SYMBOL -void evdns_base_clear_host_addresses(struct evdns_base *base); - -/** - Convert a DNS error code to a string. - - @param err the DNS error code - @return a string containing an explanation of the error code -*/ -EVENT2_EXPORT_SYMBOL -const char *evdns_err_to_string(int err); - - -/** - Add a nameserver. - - The address should be an IPv4 address in network byte order. - The type of address is chosen so that it matches in_addr.s_addr. - - @param base the evdns_base to which to add the name server - @param address an IP address in network byte order - @return 0 if successful, or -1 if an error occurred - @see evdns_base_nameserver_ip_add() - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_nameserver_add(struct evdns_base *base, - unsigned long int address); - -/** - Get the number of configured nameservers. - - This returns the number of configured nameservers (not necessarily the - number of running nameservers). This is useful for double-checking - whether our calls to the various nameserver configuration functions - have been successful. - - @param base the evdns_base to which to apply this operation - @return the number of configured nameservers - @see evdns_base_nameserver_add() - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_count_nameservers(struct evdns_base *base); - -/** - Remove all configured nameservers, and suspend all pending resolves. - - Resolves will not necessarily be re-attempted until evdns_base_resume() is called. - - @param base the evdns_base to which to apply this operation - @return 0 if successful, or -1 if an error occurred - @see evdns_base_resume() - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_clear_nameservers_and_suspend(struct evdns_base *base); - - -/** - Resume normal operation and continue any suspended resolve requests. - - Re-attempt resolves left in limbo after an earlier call to - evdns_base_clear_nameservers_and_suspend(). - - @param base the evdns_base to which to apply this operation - @return 0 if successful, or -1 if an error occurred - @see evdns_base_clear_nameservers_and_suspend() - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_resume(struct evdns_base *base); - -/** - Add a nameserver by string address. - - This function parses a n IPv4 or IPv6 address from a string and adds it as a - nameserver. It supports the following formats: - - [IPv6Address]:port - - [IPv6Address] - - IPv6Address - - IPv4Address:port - - IPv4Address - - If no port is specified, it defaults to 53. - - @param base the evdns_base to which to apply this operation - @return 0 if successful, or -1 if an error occurred - @see evdns_base_nameserver_add() - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_nameserver_ip_add(struct evdns_base *base, - const char *ip_as_string); - -/** - Add a nameserver by sockaddr. - **/ -EVENT2_EXPORT_SYMBOL -int -evdns_base_nameserver_sockaddr_add(struct evdns_base *base, - const struct sockaddr *sa, ev_socklen_t len, unsigned flags); - -struct evdns_request; - -/** - Lookup an A record for a given name. - - @param base the evdns_base to which to apply this operation - @param name a DNS hostname - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_ipv6(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -EVENT2_EXPORT_SYMBOL -struct evdns_request *evdns_base_resolve_ipv4(struct evdns_base *base, const char *name, int flags, evdns_callback_type callback, void *ptr); - -/** - Lookup an AAAA record for a given name. - - @param base the evdns_base to which to apply this operation - @param name a DNS hostname - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_ipv4(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -EVENT2_EXPORT_SYMBOL -struct evdns_request *evdns_base_resolve_ipv6(struct evdns_base *base, const char *name, int flags, evdns_callback_type callback, void *ptr); - -struct in_addr; -struct in6_addr; - -/** - Lookup a PTR record for a given IP address. - - @param base the evdns_base to which to apply this operation - @param in an IPv4 address - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -EVENT2_EXPORT_SYMBOL -struct evdns_request *evdns_base_resolve_reverse(struct evdns_base *base, const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr); - - -/** - Lookup a PTR record for a given IPv6 address. - - @param base the evdns_base to which to apply this operation - @param in an IPv6 address - @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query. - @param callback a callback function to invoke when the request is completed - @param ptr an argument to pass to the callback function - @return an evdns_request object if successful, or NULL if an error occurred. - @see evdns_resolve_reverse_ipv6(), evdns_cancel_request() - */ -EVENT2_EXPORT_SYMBOL -struct evdns_request *evdns_base_resolve_reverse_ipv6(struct evdns_base *base, const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr); - -/** - Cancels a pending DNS resolution request. - - @param base the evdns_base that was used to make the request - @param req the evdns_request that was returned by calling a resolve function - @see evdns_base_resolve_ipv4(), evdns_base_resolve_ipv6, evdns_base_resolve_reverse -*/ -EVENT2_EXPORT_SYMBOL -void evdns_cancel_request(struct evdns_base *base, struct evdns_request *req); - -/** - Set the value of a configuration option. - - The currently available configuration options are: - - ndots, timeout, max-timeouts, max-inflight, attempts, randomize-case, - bind-to, initial-probe-timeout, getaddrinfo-allow-skew. - - In versions before Libevent 2.0.3-alpha, the option name needed to end with - a colon. - - @param base the evdns_base to which to apply this operation - @param option the name of the configuration option to be modified - @param val the value to be set - @return 0 if successful, or -1 if an error occurred - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_set_option(struct evdns_base *base, const char *option, const char *val); - - -/** - Parse a resolv.conf file. - - The 'flags' parameter determines what information is parsed from the - resolv.conf file. See the man page for resolv.conf for the format of this - file. - - The following directives are not parsed from the file: sortlist, rotate, - no-check-names, inet6, debug. - - If this function encounters an error, the possible return values are: 1 = - failed to open file, 2 = failed to stat file, 3 = file too large, 4 = out of - memory, 5 = short read from file, 6 = no nameservers listed in the file - - @param base the evdns_base to which to apply this operation - @param flags any of DNS_OPTION_NAMESERVERS|DNS_OPTION_SEARCH|DNS_OPTION_MISC| - DNS_OPTION_HOSTSFILE|DNS_OPTIONS_ALL - @param filename the path to the resolv.conf file - @return 0 if successful, or various positive error codes if an error - occurred (see above) - @see resolv.conf(3), evdns_config_windows_nameservers() - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_resolv_conf_parse(struct evdns_base *base, int flags, const char *const filename); - -/** - Load an /etc/hosts-style file from 'hosts_fname' into 'base'. - - If hosts_fname is NULL, add minimal entries for localhost, and nothing - else. - - Note that only evdns_getaddrinfo uses the /etc/hosts entries. - - This function does not replace previously loaded hosts entries; to do that, - call evdns_base_clear_host_addresses first. - - Return 0 on success, negative on failure. -*/ -EVENT2_EXPORT_SYMBOL -int evdns_base_load_hosts(struct evdns_base *base, const char *hosts_fname); - -/** - Obtain nameserver information using the Windows API. - - Attempt to configure a set of nameservers based on platform settings on - a win32 host. Preferentially tries to use GetNetworkParams; if that fails, - looks in the registry. - - @return 0 if successful, or -1 if an error occurred - @see evdns_resolv_conf_parse() - */ -#ifdef _WIN32 -EVENT2_EXPORT_SYMBOL -int evdns_base_config_windows_nameservers(struct evdns_base *); -#define EVDNS_BASE_CONFIG_WINDOWS_NAMESERVERS_IMPLEMENTED -#endif - - -/** - Clear the list of search domains. - */ -EVENT2_EXPORT_SYMBOL -void evdns_base_search_clear(struct evdns_base *base); - - -/** - Add a domain to the list of search domains - - @param domain the domain to be added to the search list - */ -EVENT2_EXPORT_SYMBOL -void evdns_base_search_add(struct evdns_base *base, const char *domain); - - -/** - Set the 'ndots' parameter for searches. - - Sets the number of dots which, when found in a name, causes - the first query to be without any search domain. - - @param ndots the new ndots parameter - */ -EVENT2_EXPORT_SYMBOL -void evdns_base_search_ndots_set(struct evdns_base *base, const int ndots); - -/** - A callback that is invoked when a log message is generated - - @param is_warning indicates if the log message is a 'warning' - @param msg the content of the log message - */ -typedef void (*evdns_debug_log_fn_type)(int is_warning, const char *msg); - - -/** - Set the callback function to handle DNS log messages. If this - callback is not set, evdns log messages are handled with the regular - Libevent logging system. - - @param fn the callback to be invoked when a log message is generated - */ -EVENT2_EXPORT_SYMBOL -void evdns_set_log_fn(evdns_debug_log_fn_type fn); - -/** - Set a callback that will be invoked to generate transaction IDs. By - default, we pick transaction IDs based on the current clock time, which - is bad for security. - - @param fn the new callback, or NULL to use the default. - - NOTE: This function has no effect in Libevent 2.0.4-alpha and later, - since Libevent now provides its own secure RNG. - */ -EVENT2_EXPORT_SYMBOL -void evdns_set_transaction_id_fn(ev_uint16_t (*fn)(void)); - -/** - Set a callback used to generate random bytes. By default, we use - the same function as passed to evdns_set_transaction_id_fn to generate - bytes two at a time. If a function is provided here, it's also used - to generate transaction IDs. - - NOTE: This function has no effect in Libevent 2.0.4-alpha and later, - since Libevent now provides its own secure RNG. -*/ -EVENT2_EXPORT_SYMBOL -void evdns_set_random_bytes_fn(void (*fn)(char *, size_t)); - -/* - * Functions used to implement a DNS server. - */ - -struct evdns_server_request; -struct evdns_server_question; - -/** - A callback to implement a DNS server. The callback function receives a DNS - request. It should then optionally add a number of answers to the reply - using the evdns_server_request_add_*_reply functions, before calling either - evdns_server_request_respond to send the reply back, or - evdns_server_request_drop to decline to answer the request. - - @param req A newly received request - @param user_data A pointer that was passed to - evdns_add_server_port_with_base(). - */ -typedef void (*evdns_request_callback_fn_type)(struct evdns_server_request *, void *); -#define EVDNS_ANSWER_SECTION 0 -#define EVDNS_AUTHORITY_SECTION 1 -#define EVDNS_ADDITIONAL_SECTION 2 - -#define EVDNS_TYPE_A 1 -#define EVDNS_TYPE_NS 2 -#define EVDNS_TYPE_CNAME 5 -#define EVDNS_TYPE_SOA 6 -#define EVDNS_TYPE_PTR 12 -#define EVDNS_TYPE_MX 15 -#define EVDNS_TYPE_TXT 16 -#define EVDNS_TYPE_AAAA 28 - -#define EVDNS_QTYPE_AXFR 252 -#define EVDNS_QTYPE_ALL 255 - -#define EVDNS_CLASS_INET 1 - -/* flags that can be set in answers; as part of the err parameter */ -#define EVDNS_FLAGS_AA 0x400 -#define EVDNS_FLAGS_RD 0x080 - -/** Create a new DNS server port. - - @param base The event base to handle events for the server port. - @param socket A UDP socket to accept DNS requests. - @param flags Always 0 for now. - @param callback A function to invoke whenever we get a DNS request - on the socket. - @param user_data Data to pass to the callback. - @return an evdns_server_port structure for this server port. - */ -EVENT2_EXPORT_SYMBOL -struct evdns_server_port *evdns_add_server_port_with_base(struct event_base *base, evutil_socket_t socket, int flags, evdns_request_callback_fn_type callback, void *user_data); -/** Close down a DNS server port, and free associated structures. */ -EVENT2_EXPORT_SYMBOL -void evdns_close_server_port(struct evdns_server_port *port); - -/** Sets some flags in a reply we're building. - Allows setting of the AA or RD flags - */ -EVENT2_EXPORT_SYMBOL -void evdns_server_request_set_flags(struct evdns_server_request *req, int flags); - -/* Functions to add an answer to an in-progress DNS reply. - */ -EVENT2_EXPORT_SYMBOL -int evdns_server_request_add_reply(struct evdns_server_request *req, int section, const char *name, int type, int dns_class, int ttl, int datalen, int is_name, const char *data); -EVENT2_EXPORT_SYMBOL -int evdns_server_request_add_a_reply(struct evdns_server_request *req, const char *name, int n, const void *addrs, int ttl); -EVENT2_EXPORT_SYMBOL -int evdns_server_request_add_aaaa_reply(struct evdns_server_request *req, const char *name, int n, const void *addrs, int ttl); -EVENT2_EXPORT_SYMBOL -int evdns_server_request_add_ptr_reply(struct evdns_server_request *req, struct in_addr *in, const char *inaddr_name, const char *hostname, int ttl); -EVENT2_EXPORT_SYMBOL -int evdns_server_request_add_cname_reply(struct evdns_server_request *req, const char *name, const char *cname, int ttl); - -/** - Send back a response to a DNS request, and free the request structure. -*/ -EVENT2_EXPORT_SYMBOL -int evdns_server_request_respond(struct evdns_server_request *req, int err); -/** - Free a DNS request without sending back a reply. -*/ -EVENT2_EXPORT_SYMBOL -int evdns_server_request_drop(struct evdns_server_request *req); -struct sockaddr; -/** - Get the address that made a DNS request. - */ -EVENT2_EXPORT_SYMBOL -int evdns_server_request_get_requesting_addr(struct evdns_server_request *req, struct sockaddr *sa, int addr_len); - -/** Callback for evdns_getaddrinfo. */ -typedef void (*evdns_getaddrinfo_cb)(int result, struct evutil_addrinfo *res, void *arg); - -struct evdns_base; -struct evdns_getaddrinfo_request; -/** Make a non-blocking getaddrinfo request using the dns_base in 'dns_base'. - * - * If we can answer the request immediately (with an error or not!), then we - * invoke cb immediately and return NULL. Otherwise we return - * an evdns_getaddrinfo_request and invoke cb later. - * - * When the callback is invoked, we pass as its first argument the error code - * that getaddrinfo would return (or 0 for no error). As its second argument, - * we pass the evutil_addrinfo structures we found (or NULL on error). We - * pass 'arg' as the third argument. - * - * Limitations: - * - * - The AI_V4MAPPED and AI_ALL flags are not currently implemented. - * - For ai_socktype, we only handle SOCKTYPE_STREAM, SOCKTYPE_UDP, and 0. - * - For ai_protocol, we only handle IPPROTO_TCP, IPPROTO_UDP, and 0. - */ -EVENT2_EXPORT_SYMBOL -struct evdns_getaddrinfo_request *evdns_getaddrinfo( - struct evdns_base *dns_base, - const char *nodename, const char *servname, - const struct evutil_addrinfo *hints_in, - evdns_getaddrinfo_cb cb, void *arg); - -/* Cancel an in-progress evdns_getaddrinfo. This MUST NOT be called after the - * getaddrinfo's callback has been invoked. The resolves will be canceled, - * and the callback will be invoked with the error EVUTIL_EAI_CANCEL. */ -EVENT2_EXPORT_SYMBOL -void evdns_getaddrinfo_cancel(struct evdns_getaddrinfo_request *req); - -/** - Retrieve the address of the 'idx'th configured nameserver. - - @param base The evdns_base to examine. - @param idx The index of the nameserver to get the address of. - @param sa A location to receive the server's address. - @param len The number of bytes available at sa. - - @return the number of bytes written into sa on success. On failure, returns - -1 if idx is greater than the number of configured nameservers, or a - value greater than 'len' if len was not high enough. - */ -EVENT2_EXPORT_SYMBOL -int evdns_base_get_nameserver_addr(struct evdns_base *base, int idx, - struct sockaddr *sa, ev_socklen_t len); - -#ifdef __cplusplus -} -#endif - -#endif /* !EVENT2_DNS_H_INCLUDED_ */ |