src/libstrongswan/plugins/unbound/unbound_resolver.c

   1 /*
   2  * Copyright (C) 2011-2012 Reto Guadagnini
   3  * Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  */
  15
  16 #include <unbound.h>
  17 #include <errno.h>
  18 #include <ldns/ldns.h>
  19 #include <string.h>
  20
  21 #include <library.h>
  22 #include <utils/debug.h>
  23
  24 #include "unbound_resolver.h"
  25 #include "unbound_response.h"
  26
  27 typedef struct private_resolver_t private_resolver_t;
  28
  29 /**
  30  * private data of a unbound_resolver_t object.
  31  */
  32 struct private_resolver_t {
  33
  34         /**
  35          * Public data
  36          */
  37         resolver_t public;
  38
  39         /**
  40          * private unbound resolver handle (unbound context)
  41          */
  42         struct ub_ctx *ctx;
  43 };
  44
  45 /**
  46  * query method implementation
  47  */
  48 METHOD(resolver_t, query, resolver_response_t*,
  49         private_resolver_t *this, char *domain, rr_class_t rr_class,
  50         rr_type_t rr_type)
  51 {
  52         unbound_response_t *response = NULL;
  53         struct ub_result *result = NULL;
  54         int ub_retval;
  55
  56         ub_retval = ub_resolve(this->ctx, domain, rr_type, rr_class, &result);
  57         if (ub_retval)
  58         {
  59                 DBG1(DBG_LIB, "unbound resolver error: %s", ub_strerror(ub_retval));
  60                 ub_resolve_free(result);
  61                 return NULL;
  62         }
  63
  64         response = unbound_response_create_frm_libub_response(result);
  65         if (!response)
  66         {
  67                 DBG1(DBG_LIB, "unbound_resolver: Could not create response.");
  68                 ub_resolve_free(result);
  69                 return NULL;
  70         }
  71         ub_resolve_free(result);
  72         return (resolver_response_t*)response;
  73 }
  74
  75 /**
  76  * destroy method implementation
  77  */
  78 METHOD(resolver_t, destroy, void,
  79         private_resolver_t *this)
  80 {
  81         ub_ctx_delete(this->ctx);
  82         free(this);
  83 }
  84
  85 /*
  86  * Described in header.
  87  */
  88 resolver_t *unbound_resolver_create(char *resolv_conf, char *ta_file)
  89 {
  90         private_resolver_t *this;
  91         int ub_retval = 0;
  92
  93         INIT(this,
  94                 .public = {
  95                         .query = _query,
  96                         .destroy = _destroy,
  97                 },
  98         );
  99
 100         DBG1(DBG_LIB, "creating an unbound_resolver instance");
 101
 102         this->ctx = ub_ctx_create();
 103         if (!this->ctx)
 104         {
 105                 DBG1(DBG_LIB, "failed to create an unbound resolver context");
 106                 _destroy(this);
 107                 return NULL;
 108         }
 109
 110         ub_retval = ub_ctx_resolvconf(this->ctx, resolv_conf);
 111         if (ub_retval)
 112         {
 113                 DBG1(DBG_LIB, "failed to read the resolver configuration file. "
 114                          "Unbound error: %s. errno says: %s", ub_strerror(ub_retval),
 115                          strerror(errno));
 116                 _destroy(this);
 117                 return NULL;
 118         }
 119
 120         ub_retval = ub_ctx_add_ta_file(this->ctx, ta_file);
 121         if (ub_retval)
 122         {
 123                 DBG1(DBG_LIB, "failed to load trusted anchors from file %s. "
 124                                 "Unbound error: %s. errno says: %s",
 125                                 ta_file, ub_strerror(ub_retval), strerror(errno));
 126         }
 127
 128         DBG1(DBG_LIB, "unbound resolver instance created");
 129         return &this->public;
 130 }
 131