/* * services/outside_network.h - listen to answers from the network * * Copyright (c) 2007, NLnet Labs. All rights reserved. * * This software is open source. * * 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. * * Neither the name of the NLNET LABS nor the names of its contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "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 COPYRIGHT * HOLDER OR CONTRIBUTORS 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. */ /** * \file * * This file has functions to send queries to authoritative servers, * and wait for the pending answer, with timeouts. */ #ifndef OUTSIDE_NETWORK_H #define OUTSIDE_NETWORK_H #include "util/rbtree.h" #include "util/netevent.h" #include "dnstap/dnstap_config.h" struct pending; struct pending_timeout; struct ub_randstate; struct pending_tcp; struct waiting_tcp; struct waiting_udp; struct infra_cache; struct port_comm; struct port_if; struct sldns_buffer; struct serviced_query; struct dt_env; /** * Send queries to outside servers and wait for answers from servers. * Contains answer-listen sockets. */ struct outside_network { /** Base for select calls */ struct comm_base* base; /** pointer to time in seconds */ time_t* now_secs; /** pointer to time in microseconds */ struct timeval* now_tv; /** buffer shared by UDP connections, since there is only one datagram at any time. */ struct sldns_buffer* udp_buff; /** serviced_callbacks malloc overhead when processing multiple * identical serviced queries to the same server. */ size_t svcd_overhead; /** use x20 bits to encode additional ID random bits */ int use_caps_for_id; /** outside network wants to quit. Stop queued msgs from sent. */ int want_to_quit; /** number of unwanted replies received (for statistics) */ size_t unwanted_replies; /** cumulative total of unwanted replies (for defense) */ size_t unwanted_total; /** threshold when to take defensive action. If 0 then never. */ size_t unwanted_threshold; /** what action to take, called when defensive action is needed */ void (*unwanted_action)(void*); /** user param for action */ void* unwanted_param; /** linked list of available commpoints, unused file descriptors, * for use as outgoing UDP ports. cp.fd=-1 in them. */ struct port_comm* unused_fds; /** if udp is done */ int do_udp; /** if udp is delay-closed (delayed answers do not meet closed port)*/ int delayclose; /** timeout for delayclose */ struct timeval delay_tv; /** array of outgoing IP4 interfaces */ struct port_if* ip4_ifs; /** number of outgoing IP4 interfaces */ int num_ip4; /** array of outgoing IP6 interfaces */ struct port_if* ip6_ifs; /** number of outgoing IP6 interfaces */ int num_ip6; /** pending udp queries waiting to be sent out, waiting for fd */ struct pending* udp_wait_first; /** last pending udp query in list */ struct pending* udp_wait_last; /** pending udp answers. sorted by id, addr */ rbtree_t* pending; /** serviced queries, sorted by qbuf, addr, dnssec */ rbtree_t* serviced; /** host cache, pointer but not owned by outnet. */ struct infra_cache* infra; /** where to get random numbers */ struct ub_randstate* rnd; /** ssl context to create ssl wrapped TCP with DNS connections */ void* sslctx; #ifdef USE_DNSTAP /** dnstap environment */ struct dt_env* dtenv; #endif /** * Array of tcp pending used for outgoing TCP connections. * Each can be used to establish a TCP connection with a server. * The file descriptors are -1 if they are free, and need to be * opened for the tcp connection. Can be used for ip4 and ip6. */ struct pending_tcp **tcp_conns; /** number of tcp communication points. */ size_t num_tcp; /** number of tcp communication points in use. */ size_t num_tcp_outgoing; /** list of tcp comm points that are free for use */ struct pending_tcp* tcp_free; /** list of tcp queries waiting for a buffer */ struct waiting_tcp* tcp_wait_first; /** last of waiting query list */ struct waiting_tcp* tcp_wait_last; }; /** * Outgoing interface. Ports available and currently used are tracked * per interface */ struct port_if { /** address ready to allocate new socket (except port no). */ struct sockaddr_storage addr; /** length of addr field */ socklen_t addrlen; /** the available ports array. These are unused. * Only the first total-inuse part is filled. */ int* avail_ports; /** the total number of available ports (size of the array) */ int avail_total; /** array of the commpoints currently in use. * allocated for max number of fds, first part in use. */ struct port_comm** out; /** max number of fds, size of out array */ int maxout; /** number of commpoints (and thus also ports) in use */ int inuse; }; /** * Outgoing commpoint for UDP port. */ struct port_comm { /** next in free list */ struct port_comm* next; /** which port number (when in use) */ int number; /** interface it is used in */ struct port_if* pif; /** index in the out array of the interface */ int index; /** number of outstanding queries on this port */ int num_outstanding; /** UDP commpoint, fd=-1 if not in use */ struct comm_point* cp; }; /** * A query that has an answer pending for it. */ struct pending { /** redblacktree entry, key is the pending struct(id, addr). */ rbnode_t node; /** the ID for the query. int so that a value out of range can * be used to signify a pending that is for certain not present in * the rbtree. (and for which deletion is safe). */ unsigned int id; /** remote address. */ struct sockaddr_storage addr; /** length of addr field in use. */ socklen_t addrlen; /** comm point it was sent on (and reply must come back on). */ struct port_comm* pc; /** timeout event */ struct comm_timer* timer; /** callback for the timeout, error or reply to the message */ comm_point_callback_t* cb; /** callback user argument */ void* cb_arg; /** the outside network it is part of */ struct outside_network* outnet; /** the corresponding serviced_query */ struct serviced_query* sq; /*---- filled if udp pending is waiting -----*/ /** next in waiting list. */ struct pending* next_waiting; /** timeout in msec */ int timeout; /** The query itself, the query packet to send. */ uint8_t* pkt; /** length of query packet. */ size_t pkt_len; }; /** * Pending TCP query to server. */ struct pending_tcp { /** next in list of free tcp comm points, or NULL. */ struct pending_tcp* next_free; /** the ID for the query; checked in reply */ uint16_t id; /** tcp comm point it was sent on (and reply must come back on). */ struct comm_point* c; /** the query being serviced, NULL if the pending_tcp is unused. */ struct waiting_tcp* query; }; /** * Query waiting for TCP buffer. */ struct waiting_tcp { /** * next in waiting list. * if pkt==0, this points to the pending_tcp structure. */ struct waiting_tcp* next_waiting; /** timeout event; timer keeps running whether the query is * waiting for a buffer or the tcp reply is pending */ struct comm_timer* timer; /** the outside network it is part of */ struct outside_network* outnet; /** remote address. */ struct sockaddr_storage addr; /** length of addr field in use. */ socklen_t addrlen; /** * The query itself, the query packet to send. * allocated after the waiting_tcp structure. * set to NULL when the query is serviced and it part of pending_tcp. * if this is NULL, the next_waiting points to the pending_tcp. */ uint8_t* pkt; /** length of query packet. */ size_t pkt_len; /** callback for the timeout, error or reply to the message */ comm_point_callback_t* cb; /** callback user argument */ void* cb_arg; /** if it uses ssl upstream */ int ssl_upstream; }; /** * Callback to party interested in serviced query results. */ struct service_callback { /** next in callback list */ struct service_callback* next; /** callback function */ comm_point_callback_t* cb; /** user argument for callback function */ void* cb_arg; }; /** fallback size for fragmentation for EDNS in IPv4 */ #define EDNS_FRAG_SIZE_IP4 1472 /** fallback size for EDNS in IPv6, fits one fragment with ip6-tunnel-ids */ #define EDNS_FRAG_SIZE_IP6 1232 /** * Query service record. * Contains query and destination. UDP, TCP, EDNS are all tried. * complete with retries and timeouts. A number of interested parties can * receive a callback. */ struct serviced_query { /** The rbtree node, key is this record */ rbnode_t node; /** The query that needs to be answered. Starts with flags u16, * then qdcount, ..., including qname, qtype, qclass. Does not include * EDNS record. */ uint8_t* qbuf; /** length of qbuf. */ size_t qbuflen; /** If an EDNS section is included, the DO/CD bit will be turned on. */ int dnssec; /** We want signatures, or else the answer is likely useless */ int want_dnssec; /** ignore capsforid */ int nocaps; /** tcp upstream used, use tcp, or ssl_upstream for SSL */ int tcp_upstream, ssl_upstream; /** where to send it */ struct sockaddr_storage addr; /** length of addr field in use. */ socklen_t addrlen; /** zone name, uncompressed domain name in wireformat */ uint8_t* zone; /** length of zone name */ size_t zonelen; /** qtype */ int qtype; /** current status */ enum serviced_query_status { /** initial status */ serviced_initial, /** UDP with EDNS sent */ serviced_query_UDP_EDNS, /** UDP without EDNS sent */ serviced_query_UDP, /** TCP with EDNS sent */ serviced_query_TCP_EDNS, /** TCP without EDNS sent */ serviced_query_TCP, /** probe to test EDNS lameness (EDNS is dropped) */ serviced_query_PROBE_EDNS, /** probe to test noEDNS0 (EDNS gives FORMERRorNOTIMP) */ serviced_query_UDP_EDNS_fallback, /** probe to test TCP noEDNS0 (EDNS gives FORMERRorNOTIMP) */ serviced_query_TCP_EDNS_fallback, /** send UDP query with EDNS1480 (or 1280) */ serviced_query_UDP_EDNS_FRAG } /** variable with current status */ status; /** true if serviced_query is scheduled for deletion already */ int to_be_deleted; /** number of UDP retries */ int retry; /** time last UDP was sent */ struct timeval last_sent_time; /** rtt of last (UDP) message */ int last_rtt; /** do we know edns probe status already, for UDP_EDNS queries */ int edns_lame_known; /** outside network this is part of */ struct outside_network* outnet; /** list of interested parties that need callback on results. */ struct service_callback* cblist; /** the UDP or TCP query that is pending, see status which */ void* pending; }; /** * Create outside_network structure with N udp ports. * @param base: the communication base to use for event handling. * @param bufsize: size for network buffers. * @param num_ports: number of udp ports to open per interface. * @param ifs: interface names (or NULL for default interface). * These interfaces must be able to access all authoritative servers. * @param num_ifs: number of names in array ifs. * @param do_ip4: service IP4. * @param do_ip6: service IP6. * @param num_tcp: number of outgoing tcp buffers to preallocate. * @param infra: pointer to infra cached used for serviced queries. * @param rnd: stored to create random numbers for serviced queries. * @param use_caps_for_id: enable to use 0x20 bits to encode id randomness. * @param availports: array of available ports. * @param numavailports: number of available ports in array. * @param unwanted_threshold: when to take defensive action. * @param unwanted_action: the action to take. * @param unwanted_param: user parameter to action. * @param do_udp: if udp is done. * @param sslctx: context to create outgoing connections with (if enabled). * @param delayclose: if not 0, udp sockets are delayed before timeout closure. * msec to wait on timeouted udp sockets. * @param dtenv: environment to send dnstap events with (if enabled). * @return: the new structure (with no pending answers) or NULL on error. */ struct outside_network* outside_network_create(struct comm_base* base, size_t bufsize, size_t num_ports, char** ifs, int num_ifs, int do_ip4, int do_ip6, size_t num_tcp, struct infra_cache* infra, struct ub_randstate* rnd, int use_caps_for_id, int* availports, int numavailports, size_t unwanted_threshold, void (*unwanted_action)(void*), void* unwanted_param, int do_udp, void* sslctx, int delayclose, struct dt_env *dtenv); /** * Delete outside_network structure. * @param outnet: object to delete. */ void outside_network_delete(struct outside_network* outnet); /** * Prepare for quit. Sends no more queries, even if queued up. * @param outnet: object to prepare for removal */ void outside_network_quit_prepare(struct outside_network* outnet); /** * Send UDP query, create pending answer. * Changes the ID for the query to be random and unique for that destination. * @param sq: serviced query. * @param packet: wireformat query to send to destination. * @param timeout: in milliseconds from now. * @param callback: function to call on error, timeout or reply. * @param callback_arg: user argument for callback function. * @return: NULL on error for malloc or socket. Else the pending query object. */ struct pending* pending_udp_query(struct serviced_query* sq, struct sldns_buffer* packet, int timeout, comm_point_callback_t* callback, void* callback_arg); /** * Send TCP query. May wait for TCP buffer. Selects ID to be random, and * checks id. * @param sq: serviced query. * @param packet: wireformat query to send to destination. copied from. * @param timeout: in seconds from now. * Timer starts running now. Timer may expire if all buffers are used, * without any query been sent to the server yet. * @param callback: function to call on error, timeout or reply. * @param callback_arg: user argument for callback function. * @return: false on error for malloc or socket. Else the pending TCP object. */ struct waiting_tcp* pending_tcp_query(struct serviced_query* sq, struct sldns_buffer* packet, int timeout, comm_point_callback_t* callback, void* callback_arg); /** * Delete pending answer. * @param outnet: outside network the pending query is part of. * Internal feature: if outnet is NULL, p is not unlinked from rbtree. * @param p: deleted */ void pending_delete(struct outside_network* outnet, struct pending* p); /** * Perform a serviced query to the authoritative servers. * Duplicate efforts are detected, and EDNS, TCP and UDP retry is performed. * @param outnet: outside network, with rbtree of serviced queries. * @param qname: what qname to query. * @param qnamelen: length of qname in octets including 0 root label. * @param qtype: rrset type to query (host format) * @param qclass: query class. (host format) * @param flags: flags u16 (host format), includes opcode, CD bit. * @param dnssec: if set, DO bit is set in EDNS queries. * If the value includes BIT_CD, CD bit is set when in EDNS queries. * If the value includes BIT_DO, DO bit is set when in EDNS queries. * @param want_dnssec: signatures are needed, without EDNS the answer is * likely to be useless. * @param nocaps: ignore use_caps_for_id and use unperturbed qname. * @param tcp_upstream: use TCP for upstream queries. * @param ssl_upstream: use SSL for upstream queries. * @param callback: callback function. * @param callback_arg: user argument to callback function. * @param addr: to which server to send the query. * @param addrlen: length of addr. * @param zone: name of the zone of the delegation point. wireformat dname. This is the delegation point name for which the server is deemed authoritative. * @param zonelen: length of zone. * @param buff: scratch buffer to create query contents in. Empty on exit. * @return 0 on error, or pointer to serviced query that is used to answer * this serviced query may be shared with other callbacks as well. */ struct serviced_query* outnet_serviced_query(struct outside_network* outnet, uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, uint16_t flags, int dnssec, int want_dnssec, int nocaps, int tcp_upstream, int ssl_upstream, struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* zone, size_t zonelen, comm_point_callback_t* callback, void* callback_arg, struct sldns_buffer* buff); /** * Remove service query callback. * If that leads to zero callbacks, the query is completely cancelled. * @param sq: serviced query to adjust. * @param cb_arg: callback argument of callback that needs removal. * same as the callback_arg to outnet_serviced_query(). */ void outnet_serviced_query_stop(struct serviced_query* sq, void* cb_arg); /** * Get memory size in use by outside network. * Counts buffers and outstanding query (serviced queries) malloced data. * @param outnet: outside network structure. * @return size in bytes. */ size_t outnet_get_mem(struct outside_network* outnet); /** * Get memory size in use by serviced query while it is servicing callbacks. * This takes into account the pre-deleted status of it; it will be deleted * when the callbacks are done. * @param sq: serviced query. * @return size in bytes. */ size_t serviced_get_mem(struct serviced_query* sq); /** callback for incoming udp answers from the network */ int outnet_udp_cb(struct comm_point* c, void* arg, int error, struct comm_reply *reply_info); /** callback for pending tcp connections */ int outnet_tcp_cb(struct comm_point* c, void* arg, int error, struct comm_reply *reply_info); /** callback for udp timeout */ void pending_udp_timer_cb(void *arg); /** callback for udp delay for timeout */ void pending_udp_timer_delay_cb(void *arg); /** callback for outgoing TCP timer event */ void outnet_tcptimer(void* arg); /** callback for serviced query UDP answers */ int serviced_udp_callback(struct comm_point* c, void* arg, int error, struct comm_reply* rep); /** TCP reply or error callback for serviced queries */ int serviced_tcp_callback(struct comm_point* c, void* arg, int error, struct comm_reply* rep); /** compare function of pending rbtree */ int pending_cmp(const void* key1, const void* key2); /** compare function of serviced query rbtree */ int serviced_cmp(const void* key1, const void* key2); #endif /* OUTSIDE_NETWORK_H */