376 lines
12 KiB
C
376 lines
12 KiB
C
/*
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* services/listen_dnsport.h - listen on port 53 for incoming DNS queries.
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*
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* Copyright (c) 2007, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* This file has functions to get queries from clients.
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*/
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#ifndef LISTEN_DNSPORT_H
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#define LISTEN_DNSPORT_H
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#include "util/netevent.h"
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struct listen_list;
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struct config_file;
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struct addrinfo;
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struct sldns_buffer;
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struct tcl_list;
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/**
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* Listening for queries structure.
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* Contains list of query-listen sockets.
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*/
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struct listen_dnsport {
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/** Base for select calls */
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struct comm_base* base;
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/** buffer shared by UDP connections, since there is only one
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datagram at any time. */
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struct sldns_buffer* udp_buff;
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#ifdef USE_DNSCRYPT
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struct sldns_buffer* dnscrypt_udp_buff;
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#endif
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/** list of comm points used to get incoming events */
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struct listen_list* cps;
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};
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/**
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* Single linked list to store event points.
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*/
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struct listen_list {
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/** next in list */
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struct listen_list* next;
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/** event info */
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struct comm_point* com;
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};
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/**
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* type of ports
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*/
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enum listen_type {
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/** udp type */
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listen_type_udp,
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/** tcp type */
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listen_type_tcp,
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/** udp ipv6 (v4mapped) for use with ancillary data */
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listen_type_udpancil,
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/** ssl over tcp type */
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listen_type_ssl,
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/** udp type + dnscrypt*/
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listen_type_udp_dnscrypt,
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/** tcp type + dnscrypt */
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listen_type_tcp_dnscrypt,
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/** udp ipv6 (v4mapped) for use with ancillary data + dnscrypt*/
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listen_type_udpancil_dnscrypt
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};
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/**
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* Single linked list to store shared ports that have been
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* opened for use by all threads.
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*/
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struct listen_port {
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/** next in list */
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struct listen_port* next;
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/** file descriptor, open and ready for use */
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int fd;
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/** type of file descriptor, udp or tcp */
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enum listen_type ftype;
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};
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/**
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* Create shared listening ports
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* Getaddrinfo, create socket, bind and listen to zero or more
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* interfaces for IP4 and/or IP6, for UDP and/or TCP.
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* On the given port number. It creates the sockets.
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* @param cfg: settings on what ports to open.
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* @param reuseport: set to true if you want reuseport, or NULL to not have it,
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* set to false on exit if reuseport failed to apply (because of no
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* kernel support).
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* @return: linked list of ports or NULL on error.
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*/
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struct listen_port* listening_ports_open(struct config_file* cfg,
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int* reuseport);
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/**
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* Close and delete the (list of) listening ports.
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*/
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void listening_ports_free(struct listen_port* list);
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/**
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* Create commpoints with for this thread for the shared ports.
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* @param base: the comm_base that provides event functionality.
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* for default all ifs.
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* @param ports: the list of shared ports.
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* @param bufsize: size of datagram buffer.
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* @param tcp_accept_count: max number of simultaneous TCP connections
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* from clients.
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* @param tcp_idle_timeout: idle timeout for TCP connections in msec.
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* @param tcp_conn_limit: TCP connection limit info.
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* @param sslctx: nonNULL if ssl context.
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* @param dtenv: nonNULL if dnstap enabled.
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* @param cb: callback function when a request arrives. It is passed
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* the packet and user argument. Return true to send a reply.
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* @param cb_arg: user data argument for callback function.
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* @return: the malloced listening structure, ready for use. NULL on error.
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*/
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struct listen_dnsport* listen_create(struct comm_base* base,
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struct listen_port* ports, size_t bufsize,
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int tcp_accept_count, int tcp_idle_timeout,
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struct tcl_list* tcp_conn_limit, void* sslctx,
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struct dt_env *dtenv, comm_point_callback_type* cb, void* cb_arg);
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/**
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* delete the listening structure
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* @param listen: listening structure.
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*/
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void listen_delete(struct listen_dnsport* listen);
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/**
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* delete listen_list of commpoints. Calls commpointdelete() on items.
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* This may close the fds or not depending on flags.
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* @param list: to delete.
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*/
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void listen_list_delete(struct listen_list* list);
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/**
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* get memory size used by the listening structs
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* @param listen: listening structure.
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* @return: size in bytes.
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*/
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size_t listen_get_mem(struct listen_dnsport* listen);
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/**
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* stop accept handlers for TCP (until enabled again)
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* @param listen: listening structure.
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*/
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void listen_stop_accept(struct listen_dnsport* listen);
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/**
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* start accept handlers for TCP (was stopped before)
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* @param listen: listening structure.
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*/
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void listen_start_accept(struct listen_dnsport* listen);
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/**
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* Create and bind nonblocking UDP socket
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* @param family: for socket call.
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* @param socktype: for socket call.
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* @param addr: for bind call.
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* @param addrlen: for bind call.
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* @param v6only: if enabled, IP6 sockets get IP6ONLY option set.
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* if enabled with value 2 IP6ONLY option is disabled.
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* @param inuse: on error, this is set true if the port was in use.
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* @param noproto: on error, this is set true if cause is that the
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IPv6 proto (family) is not available.
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* @param rcv: set size on rcvbuf with socket option, if 0 it is not set.
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* @param snd: set size on sndbuf with socket option, if 0 it is not set.
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* @param listen: if true, this is a listening UDP port, eg port 53, and
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* set SO_REUSEADDR on it.
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* @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
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* listening UDP port. Set to false on return if it failed to do so.
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* @param transparent: set IP_TRANSPARENT socket option.
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* @param freebind: set IP_FREEBIND socket option.
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* @param use_systemd: if true, fetch sockets from systemd.
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* @param dscp: DSCP to use.
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* @return: the socket. -1 on error.
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*/
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int create_udp_sock(int family, int socktype, struct sockaddr* addr,
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socklen_t addrlen, int v6only, int* inuse, int* noproto, int rcv,
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int snd, int listen, int* reuseport, int transparent, int freebind, int use_systemd, int dscp);
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/**
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* Create and bind TCP listening socket
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* @param addr: address info ready to make socket.
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* @param v6only: enable ip6 only flag on ip6 sockets.
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* @param noproto: if error caused by lack of protocol support.
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* @param reuseport: if nonNULL and true, try to set SO_REUSEPORT on
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* listening UDP port. Set to false on return if it failed to do so.
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* @param transparent: set IP_TRANSPARENT socket option.
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* @param mss: maximum segment size of the socket. if zero, leaves the default.
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* @param freebind: set IP_FREEBIND socket option.
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* @param use_systemd: if true, fetch sockets from systemd.
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* @param dscp: DSCP to use.
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* @return: the socket. -1 on error.
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*/
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int create_tcp_accept_sock(struct addrinfo *addr, int v6only, int* noproto,
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int* reuseport, int transparent, int mss, int freebind, int use_systemd, int dscp);
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/**
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* Create and bind local listening socket
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* @param path: path to the socket.
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* @param noproto: on error, this is set true if cause is that local sockets
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* are not supported.
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* @param use_systemd: if true, fetch sockets from systemd.
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* @return: the socket. -1 on error.
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*/
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int create_local_accept_sock(const char* path, int* noproto, int use_systemd);
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/**
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* TCP request info. List of requests outstanding on the channel, that
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* are asked for but not yet answered back.
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*/
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struct tcp_req_info {
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/** the TCP comm point for this. Its buffer is used for read/write */
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struct comm_point* cp;
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/** the buffer to use to spool reply from mesh into,
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* it can then be copied to the result list and written.
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* it is a pointer to the shared udp buffer. */
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struct sldns_buffer* spool_buffer;
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/** are we in worker_handle function call (for recursion callback)*/
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int in_worker_handle;
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/** is the comm point dropped (by worker handle).
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* That means we have to disconnect the channel. */
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int is_drop;
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/** is the comm point set to send_reply (by mesh new client in worker
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* handle), if so answer is available in c.buffer */
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int is_reply;
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/** read channel has closed, just write pending results */
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int read_is_closed;
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/** read again */
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int read_again;
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/** number of outstanding requests */
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int num_open_req;
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/** list of outstanding requests */
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struct tcp_req_open_item* open_req_list;
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/** number of pending writeable results */
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int num_done_req;
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/** list of pending writable result packets, malloced one at a time */
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struct tcp_req_done_item* done_req_list;
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};
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/**
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* List of open items in TCP channel
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*/
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struct tcp_req_open_item {
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/** next in list */
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struct tcp_req_open_item* next;
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/** the mesh area of the mesh_state */
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struct mesh_area* mesh;
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/** the mesh state */
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struct mesh_state* mesh_state;
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};
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/**
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* List of done items in TCP channel
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*/
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struct tcp_req_done_item {
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/** next in list */
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struct tcp_req_done_item* next;
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/** the buffer with packet contents */
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uint8_t* buf;
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/** length of the buffer */
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size_t len;
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};
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/**
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* Create tcp request info structure that keeps track of open
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* requests on the TCP channel that are resolved at the same time,
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* and the pending results that have to get written back to that client.
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* @param spoolbuf: shared buffer
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* @return new structure or NULL on alloc failure.
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*/
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struct tcp_req_info* tcp_req_info_create(struct sldns_buffer* spoolbuf);
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/**
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* Delete tcp request structure. Called by owning commpoint.
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* Removes mesh entry references and stored results from the lists.
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* @param req: the tcp request info
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*/
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void tcp_req_info_delete(struct tcp_req_info* req);
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/**
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* Clear tcp request structure. Removes list entries, sets it up ready
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* for the next connection.
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* @param req: tcp request info structure.
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*/
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void tcp_req_info_clear(struct tcp_req_info* req);
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/**
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* Remove mesh state entry from list in tcp_req_info.
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* caller has to manage the mesh state reply entry in the mesh state.
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* @param req: the tcp req info that has the entry removed from the list.
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* @param m: the state removed from the list.
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*/
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void tcp_req_info_remove_mesh_state(struct tcp_req_info* req,
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struct mesh_state* m);
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/**
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* Handle write done of the last result packet
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* @param req: the tcp req info.
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*/
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void tcp_req_info_handle_writedone(struct tcp_req_info* req);
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/**
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* Handle read done of a new request from the client
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* @param req: the tcp req info.
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*/
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void tcp_req_info_handle_readdone(struct tcp_req_info* req);
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/**
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* Add mesh state to the tcp req list of open requests.
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* So the comm_reply can be removed off the mesh reply list when
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* the tcp channel has to be closed (for other reasons then that that
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* request was done, eg. channel closed by client or some format error).
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* @param req: tcp req info structure. It keeps track of the simultaneous
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* requests and results on a tcp (or TLS) channel.
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* @param mesh: mesh area for the state.
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* @param m: mesh state to add.
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* @return 0 on failure (malloc failure).
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*/
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int tcp_req_info_add_meshstate(struct tcp_req_info* req,
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struct mesh_area* mesh, struct mesh_state* m);
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/**
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* Send reply on tcp simultaneous answer channel. May queue it up.
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* @param req: request info structure.
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*/
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void tcp_req_info_send_reply(struct tcp_req_info* req);
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/** the read channel has closed
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* @param req: request. remaining queries are looked up and answered.
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* @return zero if nothing to do, just close the tcp.
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*/
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int tcp_req_info_handle_read_close(struct tcp_req_info* req);
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/** get the size of currently used tcp stream wait buffers (in bytes) */
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size_t tcp_req_info_get_stream_buffer_size(void);
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char* set_ip_dscp(int socket, int addrfamily, int ds);
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char* sock_strerror(int errn);
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#endif /* LISTEN_DNSPORT_H */
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