/** * * \file context.h * @brief getdns context management functions * * Originally taken from the getdns API description pseudo implementation. * */ /* * Copyright (c) 2013, NLnet Labs, Verisign, Inc. * 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. * * Neither the names of the copyright holders 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 Verisign, Inc. 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 _GETDNS_CONTEXT_H_ #define _GETDNS_CONTEXT_H_ #include "getdns/getdns.h" #include "getdns/getdns_extra.h" #include "config.h" #include "types-internal.h" #include "extension/libmini_event.h" #include "util/rbtree.h" struct getdns_dns_req; struct ldns_rbtree_t; struct ub_ctx; #define GETDNS_FN_RESOLVCONF "/etc/resolv.conf" #define GETDNS_FN_HOSTS "/etc/hosts" enum filechgs { GETDNS_FCHG_ERRORS = -1 , GETDNS_FCHG_NOERROR = 0 , GETDNS_FCHG_NOCHANGES = 0 , GETDNS_FCHG_MTIME = 1 , GETDNS_FCHG_CTIME = 2}; /** function pointer typedefs */ typedef void (*getdns_update_callback) (struct getdns_context *, getdns_context_code_t); /* internal use only for detecting changes to system files */ struct filechg { char *fn; int changes; int errors; struct stat *prevstat; }; typedef struct getdns_upstream { struct getdns_upstreams *upstreams; socklen_t addr_len; struct sockaddr_storage addr; /* How is this upstream doing? */ int to_retry; int back_off; /* For sharing a TCP socket to this upstream */ int fd; getdns_eventloop_event event; getdns_eventloop *loop; getdns_tcp_state tcp; /* Pipelining of TCP network requests */ getdns_network_req *write_queue; getdns_network_req *write_queue_last; getdns_rbtree_t netreq_by_query_id; } getdns_upstream; typedef struct getdns_upstreams { struct mem_funcs mf; size_t referenced; size_t count; size_t current; getdns_upstream upstreams[]; } getdns_upstreams; struct getdns_context { /* Context values */ getdns_resolution_t resolution_type; getdns_namespace_t *namespaces; int namespace_count; uint64_t timeout; getdns_redirects_t follow_redirects; struct getdns_list *dns_root_servers; getdns_append_name_t append_name; struct getdns_list *suffix; struct getdns_list *dnssec_trust_anchors; getdns_upstreams *upstreams; getdns_transport_t dns_transport; uint16_t limit_outstanding_queries; uint32_t dnssec_allowed_skew; uint8_t edns_extended_rcode; uint8_t edns_version; uint8_t edns_do_bit; uint16_t edns_maximum_udp_payload_size; getdns_update_callback update_callback; int processing; int destroying; struct mem_funcs mf; struct mem_funcs my_mf; /* The underlying contexts that do the real work */ struct ub_ctx *unbound_ctx; ldns_resolver *ldns_res; /* A tree to hold local host information*/ struct ldns_rbtree_t *local_hosts; int has_ta; /* No DNSSEC without trust anchor */ int return_dnssec_status; /* which resolution type the contexts are configured for * 0 means nothing set */ getdns_resolution_t resolution_type_set; /* * outbound requests -> transaction to getdns_dns_req */ struct ldns_rbtree_t *outbound_requests; /* Event loop extension. */ getdns_eventloop *extension; getdns_eventloop_event ub_event; /* The default extension */ getdns_mini_event mini_event; /* * state data used to detect changes to the system config files */ struct filechg *fchg_resolvconf; struct filechg *fchg_hosts; }; /* getdns_context */ /** internal functions **/ /** * Sets up the unbound contexts with stub or recursive behavior * if needed. * @param context previously initialized getdns_context * @param usenamespaces if 0 then only use the DNS, else use context namespace list * @return GETDNS_RETURN_GOOD on success */ getdns_return_t getdns_context_prepare_for_resolution(struct getdns_context *context, int usenamespaces); /* track an outbound request */ getdns_return_t getdns_context_track_outbound_request(struct getdns_dns_req *req); /* clear the outbound request from being tracked - does not cancel it */ getdns_return_t getdns_context_clear_outbound_request(struct getdns_dns_req *req); getdns_return_t getdns_context_request_timed_out(struct getdns_dns_req *req); /* cancel callback internal - flag to indicate if req should be freed and callback fired */ getdns_return_t getdns_context_cancel_request(struct getdns_context *context, getdns_transaction_t transaction_id, int fire_callback); char *getdns_strdup(const struct mem_funcs *mfs, const char *str); struct getdns_bindata *getdns_bindata_copy( struct mem_funcs *mfs, const struct getdns_bindata *src); void getdns_bindata_destroy( struct mem_funcs *mfs, struct getdns_bindata *bindata); /* perform name resolution in /etc/hosts */ getdns_return_t getdns_context_local_namespace_resolve(getdns_dns_req* req, struct getdns_dict **response, struct getdns_context *context); int filechg_check(struct getdns_context *context, struct filechg *fchg); void priv_getdns_context_ub_read_cb(void *userarg); #endif /* _GETDNS_CONTEXT_H_ */