unbound/pythonmod/pythonmod_utils.c

   1 /*
   2  * pythonmod_utils.c: utilities used by wrapper
   3  *
   4  * Copyright (c) 2009, Zdenek Vasicek (vasicek AT fit.vutbr.cz)
   5  *                     Marek Vavrusa  (xvavru00 AT stud.fit.vutbr.cz)
   6  *
   7  * This software is open source.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  *    * Redistributions of source code must retain the above copyright notice,
  14  *      this list of conditions and the following disclaimer.
  15  *
  16  *    * Redistributions in binary form must reproduce the above copyright notice,
  17  *      this list of conditions and the following disclaimer in the documentation
  18  *      and/or other materials provided with the distribution.
  19  *
  20  *    * Neither the name of the organization nor the names of its
  21  *      contributors may be used to endorse or promote products derived from this
  22  *      software without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  26  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  27  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36 /**
  37  * \file
  38  * Utility functions for the python module that perform stores and loads and
  39  * conversions.
  40  */
  41 #include "config.h"
  42 #include "util/module.h"
  43 #include "util/netevent.h"
  44 #include "util/net_help.h"
  45 #include "services/cache/dns.h"
  46 #include "services/cache/rrset.h"
  47 #include "util/data/msgparse.h"
  48 #include "util/data/msgreply.h"
  49 #include "util/storage/slabhash.h"
  50 #include "util/regional.h"
  51 #include "ldns/sbuffer.h"
  52
  53 #undef _POSIX_C_SOURCE
  54 #undef _XOPEN_SOURCE
  55 #include <Python.h>
  56
  57 /* Store the reply_info and query_info pair in message cache (qstate->msg_cache) */
  58 int storeQueryInCache(struct module_qstate* qstate, struct query_info* qinfo, struct reply_info* msgrep, int is_referral)
  59 {
  60     if (!msgrep)
  61        return 0;
  62
  63     if (msgrep->authoritative) /*authoritative answer can't be stored in cache*/
  64     {
  65        PyErr_SetString(PyExc_ValueError, "Authoritative answer can't be stored");
  66        return 0;
  67     }
  68
  69     return dns_cache_store(qstate->env, qinfo, msgrep, is_referral,
  70         qstate->prefetch_leeway, 0, NULL, qstate->query_flags);
  71 }
  72
  73 /*  Invalidate the message associated with query_info stored in message cache */
  74 void invalidateQueryInCache(struct module_qstate* qstate, struct query_info* qinfo)
  75 {
  76     hashvalue_t h;
  77     struct lruhash_entry* e;
  78     struct reply_info *r;
  79     size_t i, j;
  80
  81     h = query_info_hash(qinfo, qstate->query_flags);
  82     if ((e=slabhash_lookup(qstate->env->msg_cache, h, qinfo, 0)))
  83     {
  84         r = (struct reply_info*)(e->data);
  85         if (r)
  86         {
  87            r->ttl = 0;
  88            if(rrset_array_lock(r->ref, r->rrset_count, *qstate->env->now)) {
  89                    for(i=0; i< r->rrset_count; i++)
  90                    {
  91                        struct packed_rrset_data* data =
  92                         (struct packed_rrset_data*) r->ref[i].key->entry.data;
  93                        if(i>0 && r->ref[i].key == r->ref[i-1].key)
  94                            continue;
  95
  96                        data->ttl = r->ttl;
  97                        for(j=0; j<data->count + data->rrsig_count; j++)
  98                            data->rr_ttl[j] = r->ttl;
  99                    }
 100                    rrset_array_unlock(r->ref, r->rrset_count);
 101            }
 102         }
 103         lock_rw_unlock(&e->lock);
 104     } else {
 105         log_info("invalidateQueryInCache: qinfo is not in cache");
 106     }
 107 }
 108
 109 /* Create response according to the ldns packet content */
 110 int createResponse(struct module_qstate* qstate, sldns_buffer* pkt)
 111 {
 112     struct msg_parse* prs;
 113     struct edns_data edns;
 114
 115     /* parse message */
 116     prs = (struct msg_parse*) regional_alloc(qstate->env->scratch, sizeof(struct msg_parse));
 117     if (!prs) {
 118         log_err("storeResponse: out of memory on incoming message");
 119         return 0;
 120     }
 121
 122     memset(prs, 0, sizeof(*prs));
 123     memset(&edns, 0, sizeof(edns));
 124
 125     sldns_buffer_set_position(pkt, 0);
 126     if (parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
 127         verbose(VERB_ALGO, "storeResponse: parse error on reply packet");
 128         return 0;
 129     }
 130     /* edns is not examined, but removed from message to help cache */
 131     if(parse_extract_edns(prs, &edns) != LDNS_RCODE_NOERROR)
 132         return 0;
 133
 134     /* remove CD-bit, we asked for in case we handle validation ourself */
 135     prs->flags &= ~BIT_CD;
 136
 137     /* allocate response dns_msg in region */
 138     qstate->return_msg = (struct dns_msg*)regional_alloc(qstate->region, sizeof(struct dns_msg));
 139     if (!qstate->return_msg)
 140        return 0;
 141
 142     memset(qstate->return_msg, 0, sizeof(*qstate->return_msg));
 143     if(!parse_create_msg(pkt, prs, NULL, &(qstate->return_msg)->qinfo, &(qstate->return_msg)->rep, qstate->region)) {
 144         log_err("storeResponse: malloc failure: allocating incoming dns_msg");
 145         return 0;
 146     }
 147
 148     /* Make sure that the RA flag is set (since the presence of
 149      * this module means that recursion is available) */
 150     /* qstate->return_msg->rep->flags |= BIT_RA; */
 151
 152     /* Clear the AA flag */
 153     /* FIXME: does this action go here or in some other module? */
 154     /*qstate->return_msg->rep->flags &= ~BIT_AA; */
 155
 156     /* make sure QR flag is on */
 157     /*qstate->return_msg->rep->flags |= BIT_QR; */
 158
 159     if(verbosity >= VERB_ALGO)
 160         log_dns_msg("storeResponse: packet:", &qstate->return_msg->qinfo, qstate->return_msg->rep);
 161
 162     return 1;
 163 }
 164
 165
 166 /* Convert reply->addr to string */
 167 void reply_addr2str(struct comm_reply* reply, char* dest, int maxlen)
 168 {
 169         int af = (int)((struct sockaddr_in*) &(reply->addr))->sin_family;
 170         void* sinaddr = &((struct sockaddr_in*) &(reply->addr))->sin_addr;
 171
 172         if(af == AF_INET6)
 173                 sinaddr = &((struct sockaddr_in6*)&(reply->addr))->sin6_addr;
 174         dest[0] = 0;
 175         if (inet_ntop(af, sinaddr, dest, (socklen_t)maxlen) == 0)
 176            return;
 177         dest[maxlen-1] = 0;
 178 }