/src/unbound/util/data/msgreply.c

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/*
 * util/data/msgreply.c - store message and reply data. 
 *
 * 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 contains a data structure to store a message and its reply.
 */

#include "config.h"
#include "util/data/msgreply.h"
#include "util/storage/lookup3.h"
#include "util/log.h"
#include "util/alloc.h"
#include "util/netevent.h"
#include "util/net_help.h"
#include "util/data/dname.h"
#include "util/regional.h"
#include "util/data/msgparse.h"
#include "util/data/msgencode.h"
#include "sldns/sbuffer.h"
#include "sldns/wire2str.h"
#include "util/module.h"
#include "util/fptr_wlist.h"

/** MAX TTL default for messages and rrsets */
time_t MAX_TTL = 3600 * 24 * 10; /* ten days */
/** MIN TTL default for messages and rrsets */
time_t MIN_TTL = 0;
/** MAX Negative TTL, for SOA records in authority section */
time_t MAX_NEG_TTL = 3600; /* one hour */
/** If we serve expired entries and prefetch them */
int SERVE_EXPIRED = 0;
/** Time to serve records after expiration */
time_t SERVE_EXPIRED_TTL = 0;
/** TTL to use for expired records */
time_t SERVE_EXPIRED_REPLY_TTL = 30;
/** If we serve the original TTL or decrementing TTLs */
int SERVE_ORIGINAL_TTL = 0;

/** allocate qinfo, return 0 on error */
static int
parse_create_qinfo(sldns_buffer* pkt, struct msg_parse* msg, 
  struct query_info* qinf, struct regional* region)
{
  if(msg->qname) {
    if(region)
      qinf->qname = (uint8_t*)regional_alloc(region, 
        msg->qname_len);
    else  qinf->qname = (uint8_t*)malloc(msg->qname_len);
    if(!qinf->qname) return 0;
    dname_pkt_copy(pkt, qinf->qname, msg->qname);
  } else qinf->qname = 0;
  qinf->qname_len = msg->qname_len;
  qinf->qtype = msg->qtype;
  qinf->qclass = msg->qclass;
  qinf->local_alias = NULL;
  return 1;
}

/** constructor for replyinfo */
struct reply_info*
construct_reply_info_base(struct regional* region, uint16_t flags, size_t qd,
  time_t ttl, time_t prettl, time_t expttl, size_t an, size_t ns,
  size_t ar, size_t total, enum sec_status sec)
{
  struct reply_info* rep;
  /* rrset_count-1 because the first ref is part of the struct. */
  size_t s = sizeof(struct reply_info) - sizeof(struct rrset_ref) +
    sizeof(struct ub_packed_rrset_key*) * total;
  if(total >= RR_COUNT_MAX) return NULL; /* sanity check on numRRS*/
  if(region)
    rep = (struct reply_info*)regional_alloc(region, s);
  else  rep = (struct reply_info*)malloc(s + 
      sizeof(struct rrset_ref) * (total));
  if(!rep) 
    return NULL;
  rep->flags = flags;
  rep->qdcount = qd;
  rep->ttl = ttl;
  rep->prefetch_ttl = prettl;
  rep->serve_expired_ttl = expttl;
  rep->an_numrrsets = an;
  rep->ns_numrrsets = ns;
  rep->ar_numrrsets = ar;
  rep->rrset_count = total;
  rep->security = sec;
  rep->reason_bogus = LDNS_EDE_NONE;
  rep->authoritative = 0;
  /* array starts after the refs */
  if(region)
    rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[0]);
  else  rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[total]);
  /* zero the arrays to assist cleanup in case of malloc failure */
  memset( rep->rrsets, 0, sizeof(struct ub_packed_rrset_key*) * total);
  if(!region)
    memset( &rep->ref[0], 0, sizeof(struct rrset_ref) * total);
  return rep;
}

/** allocate replyinfo, return 0 on error */
static int
parse_create_repinfo(struct msg_parse* msg, struct reply_info** rep,
  struct regional* region)
{
  *rep = construct_reply_info_base(region, msg->flags, msg->qdcount, 0, 
    0, 0, msg->an_rrsets, msg->ns_rrsets, msg->ar_rrsets, 
    msg->rrset_count, sec_status_unchecked);
  if(!*rep)
    return 0;
  return 1;
}

int
reply_info_alloc_rrset_keys(struct reply_info* rep, struct alloc_cache* alloc,
  struct regional* region)
{
  size_t i;
  for(i=0; i<rep->rrset_count; i++) {
    if(region) {
      rep->rrsets[i] = (struct ub_packed_rrset_key*)
        regional_alloc(region, 
        sizeof(struct ub_packed_rrset_key));
      if(rep->rrsets[i]) {
        memset(rep->rrsets[i], 0, 
          sizeof(struct ub_packed_rrset_key));
        rep->rrsets[i]->entry.key = rep->rrsets[i];
      }
    }
    else  rep->rrsets[i] = alloc_special_obtain(alloc);
    if(!rep->rrsets[i])
      return 0;
    rep->rrsets[i]->entry.data = NULL;
  }
  return 1;
}

struct reply_info *
make_new_reply_info(const struct reply_info* rep, struct regional* region,
  size_t an_numrrsets, size_t copy_rrsets)
{
  struct reply_info* new_rep;
  size_t i;

  /* create a base struct.  we specify 'insecure' security status as
   * the modified response won't be DNSSEC-valid.  In our faked response
   * the authority and additional sections will be empty (except possible
   * EDNS0 OPT RR in the additional section appended on sending it out),
   * so the total number of RRsets is an_numrrsets. */
  new_rep = construct_reply_info_base(region, rep->flags,
    rep->qdcount, rep->ttl, rep->prefetch_ttl,
    rep->serve_expired_ttl, an_numrrsets, 0, 0, an_numrrsets,
    sec_status_insecure);
  if(!new_rep)
    return NULL;
  if(!reply_info_alloc_rrset_keys(new_rep, NULL, region))
    return NULL;
  for(i=0; i<copy_rrsets; i++)
    new_rep->rrsets[i] = rep->rrsets[i];

  return new_rep;
}

/** find the minimumttl in the rdata of SOA record */
static time_t
soa_find_minttl(struct rr_parse* rr)
{
  uint16_t rlen = sldns_read_uint16(rr->ttl_data+4);
  if(rlen < 20)
    return 0; /* rdata too small for SOA (dname, dname, 5*32bit) */
  /* minimum TTL is the last 32bit value in the rdata of the record */
  /* at position ttl_data + 4(ttl) + 2(rdatalen) + rdatalen - 4(timeval)*/
  return (time_t)sldns_read_uint32(rr->ttl_data+6+rlen-4);
}

/** do the rdata copy */
static int
rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to, 
  struct rr_parse* rr, time_t* rr_ttl, uint16_t type,
  sldns_pkt_section section)
{
  uint16_t pkt_len;
  const sldns_rr_descriptor* desc;

  *rr_ttl = sldns_read_uint32(rr->ttl_data);
  /* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */
  if(*rr_ttl & 0x80000000U)
    *rr_ttl = 0;
  if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
    /* negative response. see if TTL of SOA record larger than the
     * minimum-ttl in the rdata of the SOA record */
    if(*rr_ttl > soa_find_minttl(rr))
      *rr_ttl = soa_find_minttl(rr);
  }
  if(!SERVE_ORIGINAL_TTL && (*rr_ttl < MIN_TTL))
    *rr_ttl = MIN_TTL;
  if(!SERVE_ORIGINAL_TTL && (*rr_ttl > MAX_TTL))
    *rr_ttl = MAX_TTL;
  if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
    /* max neg ttl overrides the min and max ttl of everything
     * else, it is for a more specific record */
    if(*rr_ttl > MAX_NEG_TTL)
      *rr_ttl = MAX_NEG_TTL;
  }
  if(*rr_ttl < data->ttl)
    data->ttl = *rr_ttl;

  if(rr->outside_packet) {
    /* uncompressed already, only needs copy */
    memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size);
    return 1;
  }

  sldns_buffer_set_position(pkt, (size_t)
    (rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t)));
  /* insert decompressed size into rdata len stored in memory */
  /* -2 because rdatalen bytes are not included. */
  pkt_len = htons(rr->size - 2);
  memmove(to, &pkt_len, sizeof(uint16_t));
  to += 2;
  /* read packet rdata len */
  pkt_len = sldns_buffer_read_u16(pkt);
  if(sldns_buffer_remaining(pkt) < pkt_len)
    return 0;
  desc = sldns_rr_descript(type);
  if(pkt_len > 0 && desc && desc->_dname_count > 0) {
    int count = (int)desc->_dname_count;
    int rdf = 0;
    size_t len;
    size_t oldpos;
    /* decompress dnames. */
    while(pkt_len > 0 && count) {
      switch(desc->_wireformat[rdf]) {
      case LDNS_RDF_TYPE_DNAME:
        oldpos = sldns_buffer_position(pkt);
        dname_pkt_copy(pkt, to, 
          sldns_buffer_current(pkt));
        to += pkt_dname_len(pkt);
        pkt_len -= sldns_buffer_position(pkt)-oldpos;
        count--;
        len = 0;
        break;
      case LDNS_RDF_TYPE_STR:
        len = sldns_buffer_current(pkt)[0] + 1;
        break;
      default:
        len = get_rdf_size(desc->_wireformat[rdf]);
        break;
      }
      if(len) {
        log_assert(len <= pkt_len);
        memmove(to, sldns_buffer_current(pkt), len);
        to += len;
        sldns_buffer_skip(pkt, (ssize_t)len);
        pkt_len -= len;
      }
      rdf++;
    }
  }
  /* copy remaining rdata */
  if(pkt_len >  0)
    memmove(to, sldns_buffer_current(pkt), pkt_len);
  
  return 1;
}

/** copy over the data into packed rrset */
static int
parse_rr_copy(sldns_buffer* pkt, struct rrset_parse* pset, 
  struct packed_rrset_data* data)
{
  size_t i;
  struct rr_parse* rr = pset->rr_first;
  uint8_t* nextrdata;
  size_t total = pset->rr_count + pset->rrsig_count;
  data->ttl = MAX_TTL;
  data->count = pset->rr_count;
  data->rrsig_count = pset->rrsig_count;
  data->trust = rrset_trust_none;
  data->security = sec_status_unchecked;
  /* layout: struct - rr_len - rr_data - rr_ttl - rdata - rrsig */
  data->rr_len = (size_t*)((uint8_t*)data + 
    sizeof(struct packed_rrset_data));
  data->rr_data = (uint8_t**)&(data->rr_len[total]);
  data->rr_ttl = (time_t*)&(data->rr_data[total]);
  nextrdata = (uint8_t*)&(data->rr_ttl[total]);
  for(i=0; i<data->count; i++) {
    data->rr_len[i] = rr->size;
    data->rr_data[i] = nextrdata;
    nextrdata += rr->size;
    if(!rdata_copy(pkt, data, data->rr_data[i], rr, 
      &data->rr_ttl[i], pset->type, pset->section))
      return 0;
    rr = rr->next;
  }
  /* if rrsig, its rdata is at nextrdata */
  rr = pset->rrsig_first;
  for(i=data->count; i<total; i++) {
    data->rr_len[i] = rr->size;
    data->rr_data[i] = nextrdata;
    nextrdata += rr->size;
    if(!rdata_copy(pkt, data, data->rr_data[i], rr, 
      &data->rr_ttl[i], LDNS_RR_TYPE_RRSIG, pset->section))
      return 0;
    rr = rr->next;
  }
  return 1;
}

/** create rrset return 0 on failure */
static int
parse_create_rrset(sldns_buffer* pkt, struct rrset_parse* pset,
  struct packed_rrset_data** data, struct regional* region)
{
  /* allocate */
  size_t s;
  if(pset->rr_count > RR_COUNT_MAX || pset->rrsig_count > RR_COUNT_MAX ||
    pset->size > RR_COUNT_MAX)
    return 0; /* protect against integer overflow */
  s = sizeof(struct packed_rrset_data) + 
    (pset->rr_count + pset->rrsig_count) * 
    (sizeof(size_t)+sizeof(uint8_t*)+sizeof(time_t)) + 
    pset->size;
  if(region)
    *data = regional_alloc_zero(region, s);
  else  *data = calloc(1, s);
  if(!*data)
    return 0;
  /* copy & decompress */
  if(!parse_rr_copy(pkt, pset, *data)) {
    if(!region) {
      free(*data);
      *data = NULL;
    }
    return 0;
  }
  return 1;
}

/** get trust value for rrset */
static enum rrset_trust
get_rrset_trust(struct msg_parse* msg, struct rrset_parse* rrset)
{
  uint16_t AA = msg->flags & BIT_AA;
  if(rrset->section == LDNS_SECTION_ANSWER) {
    if(AA) {
      /* RFC2181 says remainder of CNAME chain is nonauth*/
      if(msg->rrset_first && 
        msg->rrset_first->section==LDNS_SECTION_ANSWER
        && msg->rrset_first->type==LDNS_RR_TYPE_CNAME){
        if(rrset == msg->rrset_first)
          return rrset_trust_ans_AA;
        else  return rrset_trust_ans_noAA;
      }
      if(msg->rrset_first && 
        msg->rrset_first->section==LDNS_SECTION_ANSWER
        && msg->rrset_first->type==LDNS_RR_TYPE_DNAME){
        if(rrset == msg->rrset_first ||
           rrset == msg->rrset_first->rrset_all_next)
          return rrset_trust_ans_AA;
        else  return rrset_trust_ans_noAA;
      }
      return rrset_trust_ans_AA;
    }
    else  return rrset_trust_ans_noAA;
  } else if(rrset->section == LDNS_SECTION_AUTHORITY) {
    if(AA) return rrset_trust_auth_AA;
    else  return rrset_trust_auth_noAA;
  } else {
    /* addit section */
    if(AA) return rrset_trust_add_AA;
    else  return rrset_trust_add_noAA;
  }
  /* NOTREACHED */
  return rrset_trust_none;
}

int
parse_copy_decompress_rrset(sldns_buffer* pkt, struct msg_parse* msg,
  struct rrset_parse *pset, struct regional* region, 
  struct ub_packed_rrset_key* pk)
{
  struct packed_rrset_data* data;
  pk->rk.flags = pset->flags;
  pk->rk.dname_len = pset->dname_len;
  if(region)
    pk->rk.dname = (uint8_t*)regional_alloc(
      region, pset->dname_len);
  else  pk->rk.dname = 
      (uint8_t*)malloc(pset->dname_len);
  if(!pk->rk.dname)
    return 0;
  /** copy & decompress dname */
  dname_pkt_copy(pkt, pk->rk.dname, pset->dname);
  /** copy over type and class */
  pk->rk.type = htons(pset->type);
  pk->rk.rrset_class = pset->rrset_class;
  /** read data part. */
  if(!parse_create_rrset(pkt, pset, &data, region)) {
    if(!region) {
      free(pk->rk.dname);
      pk->rk.dname = NULL;
    }
    return 0;
  }
  pk->entry.data = (void*)data;
  pk->entry.key = (void*)pk;
  pk->entry.hash = pset->hash;
  data->trust = get_rrset_trust(msg, pset);
  return 1;
}

/** 
 * Copy and decompress rrs
 * @param pkt: the packet for compression pointer resolution.
 * @param msg: the parsed message
 * @param rep: reply info to put rrs into.
 * @param region: if not NULL, used for allocation.
 * @return 0 on failure.
 */
static int
parse_copy_decompress(sldns_buffer* pkt, struct msg_parse* msg,
  struct reply_info* rep, struct regional* region)
{
  size_t i;
  struct rrset_parse *pset = msg->rrset_first;
  struct packed_rrset_data* data;
  log_assert(rep);
  rep->ttl = MAX_TTL;
  rep->security = sec_status_unchecked;
  if(rep->rrset_count == 0)
    rep->ttl = NORR_TTL;

  for(i=0; i<rep->rrset_count; i++) {
    if(!parse_copy_decompress_rrset(pkt, msg, pset, region,
      rep->rrsets[i]))
      return 0;
    data = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
    if(data->ttl < rep->ttl)
      rep->ttl = data->ttl;

    pset = pset->rrset_all_next;
  }
  rep->prefetch_ttl = PREFETCH_TTL_CALC(rep->ttl);
  rep->serve_expired_ttl = rep->ttl + SERVE_EXPIRED_TTL;
  return 1;
}

int 
parse_create_msg(sldns_buffer* pkt, struct msg_parse* msg,
  struct alloc_cache* alloc, struct query_info* qinf, 
  struct reply_info** rep, struct regional* region)
{
  log_assert(pkt && msg);
  if(!parse_create_qinfo(pkt, msg, qinf, region))
    return 0;
  if(!parse_create_repinfo(msg, rep, region))
    return 0;
  if(!reply_info_alloc_rrset_keys(*rep, alloc, region)) {
    if(!region) reply_info_parsedelete(*rep, alloc);
    return 0;
  }
  if(!parse_copy_decompress(pkt, msg, *rep, region)) {
    if(!region) reply_info_parsedelete(*rep, alloc);
    return 0;
  }
  return 1;
}

int reply_info_parse(sldns_buffer* pkt, struct alloc_cache* alloc,
        struct query_info* qinf, struct reply_info** rep, 
  struct regional* region, struct edns_data* edns)
{
  /* use scratch pad region-allocator during parsing. */
  struct msg_parse* msg;
  int ret;
  
  qinf->qname = NULL;
  qinf->local_alias = NULL;
  *rep = NULL;
  if(!(msg = regional_alloc(region, sizeof(*msg)))) {
    return LDNS_RCODE_SERVFAIL;
  }
  memset(msg, 0, sizeof(*msg));
  
  sldns_buffer_set_position(pkt, 0);
  if((ret = parse_packet(pkt, msg, region)) != 0) {
    return ret;
  }
  if((ret = parse_extract_edns_from_response_msg(msg, edns, region)) != 0)
    return ret;

  /* parse OK, allocate return structures */
  /* this also performs dname decompression */
  if(!parse_create_msg(pkt, msg, alloc, qinf, rep, NULL)) {
    query_info_clear(qinf);
    *rep = NULL;
    return LDNS_RCODE_SERVFAIL;
  }
  return 0;
}

/** helper compare function to sort in lock order */
static int
reply_info_sortref_cmp(const void* a, const void* b)
{
  struct rrset_ref* x = (struct rrset_ref*)a;
  struct rrset_ref* y = (struct rrset_ref*)b;
  if(x->key < y->key) return -1;
  if(x->key > y->key) return 1;
  return 0;
}

void 
reply_info_sortref(struct reply_info* rep)
{
  qsort(&rep->ref[0], rep->rrset_count, sizeof(struct rrset_ref),
    reply_info_sortref_cmp);
}

void 
reply_info_set_ttls(struct reply_info* rep, time_t timenow)
{
  size_t i, j;
  rep->ttl += timenow;
  rep->prefetch_ttl += timenow;
  rep->serve_expired_ttl += timenow;
  for(i=0; i<rep->rrset_count; i++) {
    struct packed_rrset_data* data = (struct packed_rrset_data*)
      rep->ref[i].key->entry.data;
    if(i>0 && rep->ref[i].key == rep->ref[i-1].key)
      continue;
    data->ttl += timenow;
    for(j=0; j<data->count + data->rrsig_count; j++) {
      data->rr_ttl[j] += timenow;
    }
    data->ttl_add = timenow;
  }
}

void 
reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc)
{
  size_t i;
  if(!rep) 
    return;
  /* no need to lock, since not shared in hashtables. */
  for(i=0; i<rep->rrset_count; i++) {
    ub_packed_rrset_parsedelete(rep->rrsets[i], alloc);
  }
  free(rep);
}

int 
query_info_parse(struct query_info* m, sldns_buffer* query)
{
  uint8_t* q = sldns_buffer_begin(query);
  /* minimum size: header + \0 + qtype + qclass */
  if(sldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5)
    return 0;
  if((LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY && LDNS_OPCODE_WIRE(q) !=
    LDNS_PACKET_NOTIFY) || LDNS_QDCOUNT(q) != 1 ||
    sldns_buffer_position(query) != 0)
    return 0;
  sldns_buffer_skip(query, LDNS_HEADER_SIZE);
  m->qname = sldns_buffer_current(query);
  if((m->qname_len = query_dname_len(query)) == 0)
    return 0; /* parse error */
  if(sldns_buffer_remaining(query) < 4)
    return 0; /* need qtype, qclass */
  m->qtype = sldns_buffer_read_u16(query);
  m->qclass = sldns_buffer_read_u16(query);
  m->local_alias = NULL;
  return 1;
}

/** tiny subroutine for msgreply_compare */
#define COMPARE_IT(x, y) \
  if( (x) < (y) ) return -1; \
  else if( (x) > (y) ) return +1; \
  log_assert( (x) == (y) );

int 
query_info_compare(void* m1, void* m2)
{
  struct query_info* msg1 = (struct query_info*)m1;
  struct query_info* msg2 = (struct query_info*)m2;
  int mc;
  /* from most different to least different for speed */
  COMPARE_IT(msg1->qtype, msg2->qtype);
  if((mc = query_dname_compare(msg1->qname, msg2->qname)) != 0)
    return mc;
  log_assert(msg1->qname_len == msg2->qname_len);
  COMPARE_IT(msg1->qclass, msg2->qclass);
  return 0;
#undef COMPARE_IT
}

void 
query_info_clear(struct query_info* m)
{
  free(m->qname);
  m->qname = NULL;
}

size_t 
msgreply_sizefunc(void* k, void* d)
{
  struct msgreply_entry* q = (struct msgreply_entry*)k;
  struct reply_info* r = (struct reply_info*)d;
  size_t s = sizeof(struct msgreply_entry) + sizeof(struct reply_info)
    + q->key.qname_len + lock_get_mem(&q->entry.lock)
    - sizeof(struct rrset_ref);
  s += r->rrset_count * sizeof(struct rrset_ref);
  s += r->rrset_count * sizeof(struct ub_packed_rrset_key*);
  return s;
}

void 
query_entry_delete(void *k, void* ATTR_UNUSED(arg))
{
  struct msgreply_entry* q = (struct msgreply_entry*)k;
  lock_rw_destroy(&q->entry.lock);
  query_info_clear(&q->key);
  free(q);
}

void 
reply_info_delete(void* d, void* ATTR_UNUSED(arg))
{
  struct reply_info* r = (struct reply_info*)d;
  free(r);
}

hashvalue_type
query_info_hash(struct query_info *q, uint16_t flags)
{
  hashvalue_type h = 0xab;
  h = hashlittle(&q->qtype, sizeof(q->qtype), h);
  if(q->qtype == LDNS_RR_TYPE_AAAA && (flags&BIT_CD))
    h++;
  h = hashlittle(&q->qclass, sizeof(q->qclass), h);
  h = dname_query_hash(q->qname, h);
  return h;
}

struct msgreply_entry* 
query_info_entrysetup(struct query_info* q, struct reply_info* r, 
  hashvalue_type h)
{
  struct msgreply_entry* e = (struct msgreply_entry*)malloc( 
    sizeof(struct msgreply_entry));
  if(!e) return NULL;
  memcpy(&e->key, q, sizeof(*q));
  e->entry.hash = h;
  e->entry.key = e;
  e->entry.data = r;
  lock_rw_init(&e->entry.lock);
  lock_protect(&e->entry.lock, &e->key.qname, sizeof(e->key.qname));
  lock_protect(&e->entry.lock, &e->key.qname_len, sizeof(e->key.qname_len));
  lock_protect(&e->entry.lock, &e->key.qtype, sizeof(e->key.qtype));
  lock_protect(&e->entry.lock, &e->key.qclass, sizeof(e->key.qclass));
  lock_protect(&e->entry.lock, &e->key.local_alias, sizeof(e->key.local_alias));
  lock_protect(&e->entry.lock, &e->entry.hash, sizeof(e->entry.hash));
  lock_protect(&e->entry.lock, &e->entry.key, sizeof(e->entry.key));
  lock_protect(&e->entry.lock, &e->entry.data, sizeof(e->entry.data));
  lock_protect(&e->entry.lock, e->key.qname, e->key.qname_len);
  q->qname = NULL;
  return e;
}

/** copy rrsets from replyinfo to dest replyinfo */
static int
repinfo_copy_rrsets(struct reply_info* dest, struct reply_info* from, 
  struct regional* region)
{
  size_t i, s;
  struct packed_rrset_data* fd, *dd;
  struct ub_packed_rrset_key* fk, *dk;
  for(i=0; i<dest->rrset_count; i++) {
    fk = from->rrsets[i];
    dk = dest->rrsets[i];
    fd = (struct packed_rrset_data*)fk->entry.data;
    dk->entry.hash = fk->entry.hash;
    dk->rk = fk->rk;
    if(region) {
      dk->id = fk->id;
      dk->rk.dname = (uint8_t*)regional_alloc_init(region,
        fk->rk.dname, fk->rk.dname_len);
    } else 
      dk->rk.dname = (uint8_t*)memdup(fk->rk.dname, 
        fk->rk.dname_len);
    if(!dk->rk.dname)
      return 0;
    s = packed_rrset_sizeof(fd);
    if(region)
      dd = (struct packed_rrset_data*)regional_alloc_init(
        region, fd, s);
    else  dd = (struct packed_rrset_data*)memdup(fd, s);
    if(!dd) 
      return 0;
    packed_rrset_ptr_fixup(dd);
    dk->entry.data = (void*)dd;
  }
  return 1;
}

struct reply_info* 
reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc, 
  struct regional* region)
{
  struct reply_info* cp;
  cp = construct_reply_info_base(region, rep->flags, rep->qdcount, 
    rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl, 
    rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
    rep->rrset_count, rep->security);
  if(!cp)
    return NULL;
  /* allocate ub_key structures special or not */
  if(!reply_info_alloc_rrset_keys(cp, alloc, region)) {
    if(!region)
      reply_info_parsedelete(cp, alloc);
    return NULL;
  }
  if(!repinfo_copy_rrsets(cp, rep, region)) {
    if(!region)
      reply_info_parsedelete(cp, alloc);
    return NULL;
  }
  return cp;
}

uint8_t* 
reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep)
{
  uint8_t* sname = qinfo->qname;
  size_t snamelen = qinfo->qname_len;
  size_t i;
  for(i=0; i<rep->an_numrrsets; i++) {
    struct ub_packed_rrset_key* s = rep->rrsets[i];
    /* follow CNAME chain (if any) */
    if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME && 
      ntohs(s->rk.rrset_class) == qinfo->qclass && 
      snamelen == s->rk.dname_len &&
      query_dname_compare(sname, s->rk.dname) == 0) {
      get_cname_target(s, &sname, &snamelen);
    }
  }
  if(sname != qinfo->qname)
    return sname;
  return NULL;
}

struct ub_packed_rrset_key* 
reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep)
{
  uint8_t* sname = qinfo->qname;
  size_t snamelen = qinfo->qname_len;
  size_t i;
  for(i=0; i<rep->an_numrrsets; i++) {
    struct ub_packed_rrset_key* s = rep->rrsets[i];
    /* first match type, for query of qtype cname */
    if(ntohs(s->rk.type) == qinfo->qtype && 
      ntohs(s->rk.rrset_class) == qinfo->qclass && 
      snamelen == s->rk.dname_len &&
      query_dname_compare(sname, s->rk.dname) == 0) {
      return s;
    }
    /* follow CNAME chain (if any) */
    if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME && 
      ntohs(s->rk.rrset_class) == qinfo->qclass && 
      snamelen == s->rk.dname_len &&
      query_dname_compare(sname, s->rk.dname) == 0) {
      get_cname_target(s, &sname, &snamelen);
    }
  }
  return NULL;
}

struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep,
  uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
{
  size_t i;
  for(i=0; i<rep->an_numrrsets; i++) {
    struct ub_packed_rrset_key* s = rep->rrsets[i];
    if(ntohs(s->rk.type) == type && 
      ntohs(s->rk.rrset_class) == dclass && 
      namelen == s->rk.dname_len &&
      query_dname_compare(name, s->rk.dname) == 0) {
      return s;
    }
  }
  return NULL;
}

struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep,
  uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
{
  size_t i;
  for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
    struct ub_packed_rrset_key* s = rep->rrsets[i];
    if(ntohs(s->rk.type) == type && 
      ntohs(s->rk.rrset_class) == dclass && 
      namelen == s->rk.dname_len &&
      query_dname_compare(name, s->rk.dname) == 0) {
      return s;
    }
  }
  return NULL;
}

struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep,
  uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
{
  size_t i;
  for(i=0; i<rep->rrset_count; i++) {
    struct ub_packed_rrset_key* s = rep->rrsets[i];
    if(ntohs(s->rk.type) == type && 
      ntohs(s->rk.rrset_class) == dclass && 
      namelen == s->rk.dname_len &&
      query_dname_compare(name, s->rk.dname) == 0) {
      return s;
    }
  }
  return NULL;
}

void 
log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep)
{
  /* not particularly fast but flexible, make wireformat and print */
  sldns_buffer* buf = sldns_buffer_new(65535);
  struct regional* region = regional_create();
  if(!(buf && region)) {
    log_err("%s: log_dns_msg: out of memory", str);
    sldns_buffer_free(buf);
    regional_destroy(region);
    return;
  }
  if(!reply_info_encode(qinfo, rep, 0, rep->flags, buf, 0,
    region, 65535, 1, 0)) {
    log_err("%s: log_dns_msg: out of memory", str);
  } else {
    char* s = sldns_wire2str_pkt(sldns_buffer_begin(buf),
      sldns_buffer_limit(buf));
    if(!s) {
      log_info("%s: log_dns_msg: ldns tostr failed", str);
    } else {
      log_info("%s %s", str, s);
    }
    free(s);
  }
  sldns_buffer_free(buf);
  regional_destroy(region);
}

void
log_reply_info(enum verbosity_value v, struct query_info *qinf,
  struct sockaddr_storage *addr, socklen_t addrlen, struct timeval dur,
  int cached, struct sldns_buffer *rmsg)
{
  char qname_buf[LDNS_MAX_DOMAINLEN+1];
  char clientip_buf[128];
  char rcode_buf[16];
  char type_buf[16];
  char class_buf[16];
  size_t pktlen;
  uint16_t rcode = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(rmsg, 2));

  if(verbosity < v)
    return;

  sldns_wire2str_rcode_buf((int)rcode, rcode_buf, sizeof(rcode_buf));
  addr_to_str(addr, addrlen, clientip_buf, sizeof(clientip_buf));
  if(rcode == LDNS_RCODE_FORMERR)
  {
    if(LOG_TAG_QUERYREPLY)
      log_reply("%s - - - %s - - - ", clientip_buf, rcode_buf);
    else  log_info("%s - - - %s - - - ", clientip_buf, rcode_buf);
  } else {
    if(qinf->qname)
      dname_str(qinf->qname, qname_buf);
    else  snprintf(qname_buf, sizeof(qname_buf), "null");
    pktlen = sldns_buffer_limit(rmsg);
    sldns_wire2str_type_buf(qinf->qtype, type_buf, sizeof(type_buf));
    sldns_wire2str_class_buf(qinf->qclass, class_buf, sizeof(class_buf));
    if(LOG_TAG_QUERYREPLY)
         log_reply("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
      clientip_buf, qname_buf, type_buf, class_buf,
      rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
    else log_info("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
      clientip_buf, qname_buf, type_buf, class_buf,
      rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
  }
}

void
log_query_info(enum verbosity_value v, const char* str, 
  struct query_info* qinf)
{
  log_nametypeclass(v, str, qinf->qname, qinf->qtype, qinf->qclass);
}

int
reply_check_cname_chain(struct query_info* qinfo, struct reply_info* rep) 
{
  /* check only answer section rrs for matching cname chain.
   * the cache may return changed rdata, but owner names are untouched.*/
  size_t i;
  uint8_t* sname = qinfo->qname;
  size_t snamelen = qinfo->qname_len;
  for(i=0; i<rep->an_numrrsets; i++) {
    uint16_t t = ntohs(rep->rrsets[i]->rk.type);
    if(t == LDNS_RR_TYPE_DNAME)
      continue; /* skip dnames; note TTL 0 not cached */
    /* verify that owner matches current sname */
    if(query_dname_compare(sname, rep->rrsets[i]->rk.dname) != 0){
      /* cname chain broken */
      return 0;
    }
    /* if this is a cname; move on */
    if(t == LDNS_RR_TYPE_CNAME) {
      get_cname_target(rep->rrsets[i], &sname, &snamelen);
    }
  }
  return 1;
}

int
reply_all_rrsets_secure(struct reply_info* rep) 
{
  size_t i;
  for(i=0; i<rep->rrset_count; i++) {
    if( ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
      ->security != sec_status_secure )
    return 0;
  }
  return 1;
}

struct reply_info*
parse_reply_in_temp_region(sldns_buffer* pkt, struct regional* region,
  struct query_info* qi)
{
  struct reply_info* rep;
  struct msg_parse* msg;
  if(!(msg = regional_alloc(region, sizeof(*msg)))) {
    return NULL;
  }
  memset(msg, 0, sizeof(*msg));
  sldns_buffer_set_position(pkt, 0);
  if(parse_packet(pkt, msg, region) != 0){
    return 0;
  }
  if(!parse_create_msg(pkt, msg, NULL, qi, &rep, region)) {
    return 0;
  }
  return rep;
}

int edns_opt_list_append_ede(struct edns_option** list, struct regional* region,
  sldns_ede_code code, const char *txt)
{
  struct edns_option** prevp;
  struct edns_option* opt;
  size_t txt_len = txt ? strlen(txt) : 0;

  /* allocate new element */
  opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
  if(!opt)
    return 0;
  opt->next = NULL;
  opt->opt_code = LDNS_EDNS_EDE;
  opt->opt_len = txt_len + sizeof(uint16_t);
  opt->opt_data = regional_alloc(region, txt_len + sizeof(uint16_t));
  if(!opt->opt_data)
    return 0;
  sldns_write_uint16(opt->opt_data, (uint16_t)code);
  if (txt_len)
    memmove(opt->opt_data + 2, txt, txt_len);

  /* append at end of list */
  prevp = list;
  while(*prevp != NULL)
    prevp = &((*prevp)->next);
  verbose(VERB_ALGO, "attached EDE code: %d with message: %s", code, (txt?txt:"\"\""));
  *prevp = opt;
  return 1;
}

int edns_opt_list_append(struct edns_option** list, uint16_t code, size_t len,
  uint8_t* data, struct regional* region)
{
  struct edns_option** prevp;
  struct edns_option* opt;

  /* allocate new element */
  opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
  if(!opt)
    return 0;
  opt->next = NULL;
  opt->opt_code = code;
  opt->opt_len = len;
  opt->opt_data = NULL;
  if(len > 0) {
    opt->opt_data = regional_alloc_init(region, data, len);
    if(!opt->opt_data)
      return 0;
  }

  /* append at end of list */
  prevp = list;
  while(*prevp != NULL) {
    prevp = &((*prevp)->next);
  }
  *prevp = opt;
  return 1;
}

int edns_opt_list_remove(struct edns_option** list, uint16_t code)
{
  /* The list should already be allocated in a region. Freeing the
   * allocated space in a region is not possible. We just unlink the
   * required elements and they will be freed together with the region. */

  struct edns_option* prev;
  struct edns_option* curr;
  if(!list || !(*list)) return 0;

  /* Unlink and repoint if the element(s) are first in list */
  while(list && *list && (*list)->opt_code == code) {
    *list = (*list)->next;
  }

  if(!list || !(*list)) return 1;
  /* Unlink elements and reattach the list */
  prev = *list;
  curr = (*list)->next;
  while(curr != NULL) {
    if(curr->opt_code == code) {
      prev->next = curr->next;
      curr = curr->next;
    } else {
      prev = curr;
      curr = curr->next;
    }
  }
  return 1;
}

static int inplace_cb_reply_call_generic(
    struct inplace_cb* callback_list, enum inplace_cb_list_type type,
  struct query_info* qinfo, struct module_qstate* qstate,
  struct reply_info* rep, int rcode, struct edns_data* edns,
  struct comm_reply* repinfo, struct regional* region,
  struct timeval* start_time)
{
  struct inplace_cb* cb;
  struct edns_option* opt_list_out = NULL;
#if defined(EXPORT_ALL_SYMBOLS)
  (void)type; /* param not used when fptr_ok disabled */
#endif
  if(qstate)
    opt_list_out = qstate->edns_opts_front_out;
  for(cb=callback_list; cb; cb=cb->next) {
    fptr_ok(fptr_whitelist_inplace_cb_reply_generic(
      (inplace_cb_reply_func_type*)cb->cb, type));
    (void)(*(inplace_cb_reply_func_type*)cb->cb)(qinfo, qstate, rep,
      rcode, edns, &opt_list_out, repinfo, region, start_time, cb->id, cb->cb_arg);
  }
  edns->opt_list_inplace_cb_out = opt_list_out;
  return 1;
}

int inplace_cb_reply_call(struct module_env* env, struct query_info* qinfo,
  struct module_qstate* qstate, struct reply_info* rep, int rcode,
  struct edns_data* edns, struct comm_reply* repinfo, struct regional* region,
  struct timeval* start_time)
{
  return inplace_cb_reply_call_generic(
    env->inplace_cb_lists[inplace_cb_reply], inplace_cb_reply, qinfo,
    qstate, rep, rcode, edns, repinfo, region, start_time);
}

int inplace_cb_reply_cache_call(struct module_env* env,
  struct query_info* qinfo, struct module_qstate* qstate,
  struct reply_info* rep, int rcode, struct edns_data* edns,
  struct comm_reply* repinfo, struct regional* region,
  struct timeval* start_time)
{
  return inplace_cb_reply_call_generic(
    env->inplace_cb_lists[inplace_cb_reply_cache], inplace_cb_reply_cache,
    qinfo, qstate, rep, rcode, edns, repinfo, region, start_time);
}

int inplace_cb_reply_local_call(struct module_env* env,
  struct query_info* qinfo, struct module_qstate* qstate,
  struct reply_info* rep, int rcode, struct edns_data* edns,
  struct comm_reply* repinfo, struct regional* region,
  struct timeval* start_time)
{
  return inplace_cb_reply_call_generic(
    env->inplace_cb_lists[inplace_cb_reply_local], inplace_cb_reply_local,
    qinfo, qstate, rep, rcode, edns, repinfo, region, start_time);
}

int inplace_cb_reply_servfail_call(struct module_env* env,
  struct query_info* qinfo, struct module_qstate* qstate,
  struct reply_info* rep, int rcode, struct edns_data* edns,
  struct comm_reply* repinfo, struct regional* region,
  struct timeval* start_time)
{
  /* We are going to servfail. Remove any potential edns options. */
  if(qstate)
    qstate->edns_opts_front_out = NULL;
  return inplace_cb_reply_call_generic(
    env->inplace_cb_lists[inplace_cb_reply_servfail],
    inplace_cb_reply_servfail, qinfo, qstate, rep, rcode, edns, repinfo,
    region, start_time);
}

int inplace_cb_query_call(struct module_env* env, struct query_info* qinfo,
  uint16_t flags, struct sockaddr_storage* addr, socklen_t addrlen,
  uint8_t* zone, size_t zonelen, struct module_qstate* qstate,
  struct regional* region)
{
  struct inplace_cb* cb = env->inplace_cb_lists[inplace_cb_query];
  for(; cb; cb=cb->next) {
    fptr_ok(fptr_whitelist_inplace_cb_query(
      (inplace_cb_query_func_type*)cb->cb));
    (void)(*(inplace_cb_query_func_type*)cb->cb)(qinfo, flags,
      qstate, addr, addrlen, zone, zonelen, region,
      cb->id, cb->cb_arg);
  }
  return 1;
}

int inplace_cb_edns_back_parsed_call(struct module_env* env, 
  struct module_qstate* qstate)
{
  struct inplace_cb* cb =
    env->inplace_cb_lists[inplace_cb_edns_back_parsed];
  for(; cb; cb=cb->next) {
    fptr_ok(fptr_whitelist_inplace_cb_edns_back_parsed(
      (inplace_cb_edns_back_parsed_func_type*)cb->cb));
    (void)(*(inplace_cb_edns_back_parsed_func_type*)cb->cb)(qstate,
      cb->id, cb->cb_arg);
  }
  return 1;
}

int inplace_cb_query_response_call(struct module_env* env,
  struct module_qstate* qstate, struct dns_msg* response) {
  struct inplace_cb* cb =
    env->inplace_cb_lists[inplace_cb_query_response];
  for(; cb; cb=cb->next) {
    fptr_ok(fptr_whitelist_inplace_cb_query_response(
      (inplace_cb_query_response_func_type*)cb->cb));
    (void)(*(inplace_cb_query_response_func_type*)cb->cb)(qstate,
      response, cb->id, cb->cb_arg);
  }
  return 1;
}

struct edns_option* edns_opt_copy_region(struct edns_option* list,
        struct regional* region)
{
  struct edns_option* result = NULL, *cur = NULL, *s;
  while(list) {
    /* copy edns option structure */
    s = regional_alloc_init(region, list, sizeof(*list));
    if(!s) return NULL;
    s->next = NULL;

    /* copy option data */
    if(s->opt_data) {
      s->opt_data = regional_alloc_init(region, s->opt_data,
        s->opt_len);
      if(!s->opt_data)
        return NULL;
    }

    /* link into list */
    if(cur)
      cur->next = s;
    else  result = s;
    cur = s;

    /* examine next element */
    list = list->next;
  }
  return result;
}

int edns_opt_compare(struct edns_option* p, struct edns_option* q)
{
  if(!p && !q) return 0;
  if(!p) return -1;
  if(!q) return 1;
  log_assert(p && q);
  if(p->opt_code != q->opt_code)
    return (int)q->opt_code - (int)p->opt_code;
  if(p->opt_len != q->opt_len)
    return (int)q->opt_len - (int)p->opt_len;
  if(p->opt_len != 0)
    return memcmp(p->opt_data, q->opt_data, p->opt_len);
  return 0;
}

int edns_opt_list_compare(struct edns_option* p, struct edns_option* q)
{
  int r;
  while(p && q) {
    r = edns_opt_compare(p, q);
    if(r != 0)
      return r;
    p = p->next;
    q = q->next;
  }
  if(p || q) {
    /* uneven length lists */
    if(p) return 1;
    if(q) return -1;
  }
  return 0;
}

void edns_opt_list_free(struct edns_option* list)
{
  struct edns_option* n;
  while(list) {
    free(list->opt_data);
    n = list->next;
    free(list);
    list = n;
  }
}

struct edns_option* edns_opt_copy_alloc(struct edns_option* list)
{
  struct edns_option* result = NULL, *cur = NULL, *s;
  while(list) {
    /* copy edns option structure */
    s = memdup(list, sizeof(*list));
    if(!s) {
      edns_opt_list_free(result);
      return NULL;
    }
    s->next = NULL;

    /* copy option data */
    if(s->opt_data) {
      s->opt_data = memdup(s->opt_data, s->opt_len);
      if(!s->opt_data) {
        free(s);
        edns_opt_list_free(result);
        return NULL;
      }
    }

    /* link into list */
    if(cur)
      cur->next = s;
    else  result = s;
    cur = s;

    /* examine next element */
    list = list->next;
  }
  return result;
}

struct edns_option* edns_opt_list_find(struct edns_option* list, uint16_t code)
{
  struct edns_option* p;
  for(p=list; p; p=p->next) {
    if(p->opt_code == code)
      return p;
  }
  return NULL;
}

Coverage Report

Created: 2023-06-07 06:25