/src/unbound/sldns/wire2str.c

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/*
 * wire2str.c
 *
 * conversion routines from the wire format
 * to the presentation format (strings)
 *
 * (c) NLnet Labs, 2004-2006
 *
 * See the file LICENSE for the license
 */
/**
 * \file
 *
 * Contains functions to translate the wireformat to text
 * representation, as well as functions to print them.
 */
#include "config.h"
#include "sldns/wire2str.h"
#include "sldns/str2wire.h"
#include "sldns/rrdef.h"
#include "sldns/pkthdr.h"
#include "sldns/parseutil.h"
#include "sldns/sbuffer.h"
#include "sldns/keyraw.h"
#include "util/data/dname.h"
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#include <sys/time.h>
#include <stdarg.h>
#include <ctype.h>
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif

/* lookup tables for standard DNS stuff  */
/* Taken from RFC 2535, section 7.  */
static sldns_lookup_table sldns_algorithms_data[] = {
  { LDNS_RSAMD5, "RSAMD5" },
  { LDNS_DH, "DH" },
  { LDNS_DSA, "DSA" },
  { LDNS_ECC, "ECC" },
  { LDNS_RSASHA1, "RSASHA1" },
  { LDNS_DSA_NSEC3, "DSA-NSEC3-SHA1" },
  { LDNS_RSASHA1_NSEC3, "RSASHA1-NSEC3-SHA1" },
  { LDNS_RSASHA256, "RSASHA256"},
  { LDNS_RSASHA512, "RSASHA512"},
  { LDNS_ECC_GOST, "ECC-GOST"},
  { LDNS_ECDSAP256SHA256, "ECDSAP256SHA256"},
  { LDNS_ECDSAP384SHA384, "ECDSAP384SHA384"},
  { LDNS_ED25519, "ED25519"},
  { LDNS_ED448, "ED448"},
  { LDNS_INDIRECT, "INDIRECT" },
  { LDNS_PRIVATEDNS, "PRIVATEDNS" },
  { LDNS_PRIVATEOID, "PRIVATEOID" },
  { 0, NULL }
};
sldns_lookup_table* sldns_algorithms = sldns_algorithms_data;

/* hash algorithms in DS record */
static sldns_lookup_table sldns_hashes_data[] = {
  { LDNS_SHA1, "SHA1" },
  { LDNS_SHA256, "SHA256" },
  { LDNS_HASH_GOST, "HASH-GOST" },
  { LDNS_SHA384, "SHA384" },
  { 0, NULL }
};
sldns_lookup_table* sldns_hashes = sldns_hashes_data;

/* Taken from RFC 4398  */
static sldns_lookup_table sldns_cert_algorithms_data[] = {
  { LDNS_CERT_PKIX, "PKIX" },
  { LDNS_CERT_SPKI, "SPKI" },
  { LDNS_CERT_PGP, "PGP" },
  { LDNS_CERT_IPKIX, "IPKIX" },
  { LDNS_CERT_ISPKI, "ISPKI" },
  { LDNS_CERT_IPGP, "IPGP" },
  { LDNS_CERT_ACPKIX, "ACPKIX" },
  { LDNS_CERT_IACPKIX, "IACPKIX" },
  { LDNS_CERT_URI, "URI" },
  { LDNS_CERT_OID, "OID" },
  { 0, NULL }
};
sldns_lookup_table* sldns_cert_algorithms = sldns_cert_algorithms_data;

/* if these are used elsewhere */
static sldns_lookup_table sldns_rcodes_data[] = {
  { LDNS_RCODE_NOERROR, "NOERROR" },
  { LDNS_RCODE_FORMERR, "FORMERR" },
  { LDNS_RCODE_SERVFAIL, "SERVFAIL" },
  { LDNS_RCODE_NXDOMAIN, "NXDOMAIN" },
  { LDNS_RCODE_NOTIMPL, "NOTIMPL" },
  { LDNS_RCODE_REFUSED, "REFUSED" },
  { LDNS_RCODE_YXDOMAIN, "YXDOMAIN" },
  { LDNS_RCODE_YXRRSET, "YXRRSET" },
  { LDNS_RCODE_NXRRSET, "NXRRSET" },
  { LDNS_RCODE_NOTAUTH, "NOTAUTH" },
  { LDNS_RCODE_NOTZONE, "NOTZONE" },
  { 0, NULL }
};
sldns_lookup_table* sldns_rcodes = sldns_rcodes_data;

static sldns_lookup_table sldns_opcodes_data[] = {
  { LDNS_PACKET_QUERY, "QUERY" },
  { LDNS_PACKET_IQUERY, "IQUERY" },
  { LDNS_PACKET_STATUS, "STATUS" },
  { LDNS_PACKET_NOTIFY, "NOTIFY" },
  { LDNS_PACKET_UPDATE, "UPDATE" },
  { 0, NULL }
};
sldns_lookup_table* sldns_opcodes = sldns_opcodes_data;

static sldns_lookup_table sldns_wireparse_errors_data[] = {
  { LDNS_WIREPARSE_ERR_OK, "no parse error" },
  { LDNS_WIREPARSE_ERR_GENERAL, "parse error" },
  { LDNS_WIREPARSE_ERR_DOMAINNAME_OVERFLOW, "Domainname length overflow" },
  { LDNS_WIREPARSE_ERR_DOMAINNAME_UNDERFLOW, "Domainname length underflow (zero length)" },
  { LDNS_WIREPARSE_ERR_BUFFER_TOO_SMALL, "buffer too small" },
  { LDNS_WIREPARSE_ERR_LABEL_OVERFLOW, "Label length overflow" },
  { LDNS_WIREPARSE_ERR_EMPTY_LABEL, "Empty label" },
  { LDNS_WIREPARSE_ERR_SYNTAX_BAD_ESCAPE, "Syntax error, bad escape sequence" },
  { LDNS_WIREPARSE_ERR_SYNTAX, "Syntax error, could not parse the RR" },
  { LDNS_WIREPARSE_ERR_SYNTAX_TTL, "Syntax error, could not parse the RR's TTL" },
  { LDNS_WIREPARSE_ERR_SYNTAX_TYPE, "Syntax error, could not parse the RR's type" },
  { LDNS_WIREPARSE_ERR_SYNTAX_CLASS, "Syntax error, could not parse the RR's class" },
  { LDNS_WIREPARSE_ERR_SYNTAX_RDATA, "Syntax error, could not parse the RR's rdata" },
  { LDNS_WIREPARSE_ERR_SYNTAX_MISSING_VALUE, "Syntax error, value expected" },
  { LDNS_WIREPARSE_ERR_INVALID_STR, "Conversion error, string expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_B64, "Conversion error, b64 encoding expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_B32_EXT, "Conversion error, b32 ext encoding expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_HEX, "Conversion error, hex encoding expected" },
  { LDNS_WIREPARSE_ERR_CERT_BAD_ALGORITHM, "Bad algorithm type for CERT record" },
  { LDNS_WIREPARSE_ERR_SYNTAX_TIME, "Conversion error, time encoding expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_PERIOD, "Conversion error, time period encoding expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_ILNP64, "Conversion error, 4 colon separated hex numbers expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_EUI48,
    "Conversion error, 6 two character hex numbers "
    "separated by dashes expected (i.e. xx-xx-xx-xx-xx-xx" },
  { LDNS_WIREPARSE_ERR_SYNTAX_EUI64,
    "Conversion error, 8 two character hex numbers "
    "separated by dashes expected (i.e. xx-xx-xx-xx-xx-xx-xx-xx" },
  { LDNS_WIREPARSE_ERR_SYNTAX_TAG,
    "Conversion error, a non-zero sequence of US-ASCII letters "
    "and numbers in lower case expected" },
  { LDNS_WIREPARSE_ERR_NOT_IMPL, "not implemented" },
  { LDNS_WIREPARSE_ERR_SYNTAX_INT, "Conversion error, integer expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_IP4, "Conversion error, ip4 addr expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_IP6, "Conversion error, ip6 addr expected" },
  { LDNS_WIREPARSE_ERR_SYNTAX_INTEGER_OVERFLOW, "Syntax error, integer overflow" },
  { LDNS_WIREPARSE_ERR_INCLUDE, "$INCLUDE directive was seen in the zone" },
  { LDNS_WIREPARSE_ERR_PARENTHESIS, "Parse error, parenthesis mismatch" },
  { LDNS_WIREPARSE_ERR_SVCB_UNKNOWN_KEY, "Unknown SvcParamKey"},
  { LDNS_WIREPARSE_ERR_SVCB_MISSING_PARAM, "SvcParam is missing a SvcParamValue"},
  { LDNS_WIREPARSE_ERR_SVCB_DUPLICATE_KEYS, "Duplicate SVCB key found"},
  { LDNS_WIREPARSE_ERR_SVCB_MANDATORY_TOO_MANY_KEYS, "Too many keys in mandatory" },
  { LDNS_WIREPARSE_ERR_SVCB_TOO_MANY_PARAMS,
    "Too many SvcParams. Unbound only allows 63 entries" },
  { LDNS_WIREPARSE_ERR_SVCB_MANDATORY_MISSING_PARAM,
    "Mandatory SvcParamKey is missing"},
  { LDNS_WIREPARSE_ERR_SVCB_MANDATORY_DUPLICATE_KEY,
    "Keys in SvcParam mandatory MUST be unique" },
  { LDNS_WIREPARSE_ERR_SVCB_MANDATORY_IN_MANDATORY, 
    "mandatory MUST not be included as mandatory parameter" },
  { LDNS_WIREPARSE_ERR_SVCB_PORT_VALUE_SYNTAX,
    "Could not parse port SvcParamValue" },
  { LDNS_WIREPARSE_ERR_SVCB_IPV4_TOO_MANY_ADDRESSES,
    "Too many IPv4 addresses in ipv4hint" },
  { LDNS_WIREPARSE_ERR_SVCB_IPV6_TOO_MANY_ADDRESSES,
    "Too many IPv6 addresses in ipv6hint" },
  { LDNS_WIREPARSE_ERR_SVCB_ALPN_KEY_TOO_LARGE,
    "Alpn strings need to be smaller than 255 chars"},
  { LDNS_WIREPARSE_ERR_SVCB_NO_DEFAULT_ALPN_VALUE,
    "No-default-alpn should not have a value" },
  { LDNS_WIREPARSE_ERR_SVCPARAM_BROKEN_RDATA,
    "General SVCParam error" },
  { 0, NULL }
};
sldns_lookup_table* sldns_wireparse_errors = sldns_wireparse_errors_data;

static sldns_lookup_table sldns_edns_flags_data[] = {
  { 3600, "do"},
  { 0, NULL}
};
sldns_lookup_table* sldns_edns_flags = sldns_edns_flags_data;

static sldns_lookup_table sldns_edns_options_data[] = {
  { 1, "LLQ" },
  { 2, "UL" },
  { 3, "NSID" },
  /* 4 draft-cheshire-edns0-owner-option */
  { 5, "DAU" },
  { 6, "DHU" },
  { 7, "N3U" },
  { 8, "edns-client-subnet" },
  { 11, "edns-tcp-keepalive"},
  { 12, "Padding" },
  { 15, "EDE"},
  { 0, NULL}
};
sldns_lookup_table* sldns_edns_options = sldns_edns_options_data;

static sldns_lookup_table sldns_tsig_errors_data[] = {
  { LDNS_TSIG_ERROR_NOERROR, "NOERROR" },
  { LDNS_RCODE_FORMERR, "FORMERR" },
  { LDNS_RCODE_SERVFAIL, "SERVFAIL" },
  { LDNS_RCODE_NXDOMAIN, "NXDOMAIN" },
  { LDNS_RCODE_NOTIMPL, "NOTIMPL" },
  { LDNS_RCODE_REFUSED, "REFUSED" },
  { LDNS_RCODE_YXDOMAIN, "YXDOMAIN" },
  { LDNS_RCODE_YXRRSET, "YXRRSET" },
  { LDNS_RCODE_NXRRSET, "NXRRSET" },
  { LDNS_RCODE_NOTAUTH, "NOTAUTH" },
  { LDNS_RCODE_NOTZONE, "NOTZONE" },
  { LDNS_TSIG_ERROR_BADSIG, "BADSIG" },
  { LDNS_TSIG_ERROR_BADKEY, "BADKEY" },
  { LDNS_TSIG_ERROR_BADTIME, "BADTIME" },
  { LDNS_TSIG_ERROR_BADMODE, "BADMODE" },
  { LDNS_TSIG_ERROR_BADNAME, "BADNAME" },
  { LDNS_TSIG_ERROR_BADALG, "BADALG" },
  { 0, NULL }
};
sldns_lookup_table* sldns_tsig_errors = sldns_tsig_errors_data;

/* draft-ietf-dnsop-svcb-https-06: 6. Initial SvcParamKeys */
const char *svcparamkey_strs[] = {
  "mandatory", "alpn", "no-default-alpn", "port",
  "ipv4hint", "ech", "ipv6hint"
};

char* sldns_wire2str_pkt(uint8_t* data, size_t len)
{
  size_t slen = (size_t)sldns_wire2str_pkt_buf(data, len, NULL, 0);
  char* result = (char*)malloc(slen+1);
  if(!result) return NULL;
  sldns_wire2str_pkt_buf(data, len, result, slen+1);
  return result;
}

char* sldns_wire2str_rr(uint8_t* rr, size_t len)
{
  size_t slen = (size_t)sldns_wire2str_rr_buf(rr, len, NULL, 0);
  char* result = (char*)malloc(slen+1);
  if(!result) return NULL;
  sldns_wire2str_rr_buf(rr, len, result, slen+1);
  return result;
}

char* sldns_wire2str_type(uint16_t rrtype)
{
  char buf[16];
  sldns_wire2str_type_buf(rrtype, buf, sizeof(buf));
  return strdup(buf);
}

char* sldns_wire2str_class(uint16_t rrclass)
{
  char buf[16];
  sldns_wire2str_class_buf(rrclass, buf, sizeof(buf));
  return strdup(buf);
}

char* sldns_wire2str_dname(uint8_t* dname, size_t dname_len)
{
  size_t slen=(size_t)sldns_wire2str_dname_buf(dname, dname_len, NULL, 0);
  char* result = (char*)malloc(slen+1);
  if(!result) return NULL;
  sldns_wire2str_dname_buf(dname, dname_len, result, slen+1);
  return result;
}

char* sldns_wire2str_rcode(int rcode)
{
  char buf[16];
  sldns_wire2str_rcode_buf(rcode, buf, sizeof(buf));
  return strdup(buf);
}

int sldns_wire2str_pkt_buf(uint8_t* d, size_t dlen, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_pkt_scan(&d, &dlen, &s, &slen);
}

int sldns_wire2str_rr_buf(uint8_t* d, size_t dlen, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_rr_scan(&d, &dlen, &s, &slen, NULL, 0, NULL);
}

int sldns_wire2str_rrquestion_buf(uint8_t* d, size_t dlen, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_rrquestion_scan(&d, &dlen, &s, &slen, NULL, 0, NULL);
}

int sldns_wire2str_rdata_buf(uint8_t* rdata, size_t rdata_len, char* str,
  size_t str_len, uint16_t rrtype)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_rdata_scan(&rdata, &rdata_len, &str, &str_len,
    rrtype, NULL, 0, NULL);
}

int sldns_wire2str_rr_unknown_buf(uint8_t* d, size_t dlen, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_rr_unknown_scan(&d, &dlen, &s, &slen, NULL, 0, NULL);
}

int sldns_wire2str_rr_comment_buf(uint8_t* rr, size_t rrlen, size_t dname_len,
  char* s, size_t slen)
{
  uint16_t rrtype = sldns_wirerr_get_type(rr, rrlen, dname_len);
  return sldns_wire2str_rr_comment_print(&s, &slen, rr, rrlen, dname_len,
    rrtype);
}

int sldns_wire2str_type_buf(uint16_t rrtype, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_type_print(&s, &slen, rrtype);
}

int sldns_wire2str_class_buf(uint16_t rrclass, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_class_print(&s, &slen, rrclass);
}

int sldns_wire2str_rcode_buf(int rcode, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_rcode_print(&s, &slen, rcode);
}

int sldns_wire2str_opcode_buf(int opcode, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_opcode_print(&s, &slen, opcode);
}

int sldns_wire2str_dname_buf(uint8_t* d, size_t dlen, char* s, size_t slen)
{
  /* use arguments as temporary variables */
  return sldns_wire2str_dname_scan(&d, &dlen, &s, &slen, NULL, 0, NULL);
}

int sldns_str_vprint(char** str, size_t* slen, const char* format, va_list args)
{
  int w = vsnprintf(*str, *slen, format, args);
  if(w < 0) {
    /* error in printout */
    return 0;
  } else if((size_t)w >= *slen) {
    *str = NULL; /* we do not want str to point outside of buffer*/
    *slen = 0;
  } else {
    *str += w;
    *slen -= w;
  }
  return w;
}

int sldns_str_print(char** str, size_t* slen, const char* format, ...)
{
  int w;
  va_list args;
  va_start(args, format);
  w = sldns_str_vprint(str, slen, format, args);
  va_end(args);
  return w;
}

/** print hex format into text buffer for specified length */
static int print_hex_buf(char** s, size_t* slen, uint8_t* buf, size_t len)
{
  const char* hex = "0123456789ABCDEF";
  size_t i;
  for(i=0; i<len; i++) {
    (void)sldns_str_print(s, slen, "%c%c", hex[(buf[i]&0xf0)>>4],
      hex[buf[i]&0x0f]);
  }
  return (int)len*2;
}

/** print remainder of buffer in hex format with prefixed text */
static int print_remainder_hex(const char* pref, uint8_t** d, size_t* dlen,
  char** s, size_t* slen)
{
  int w = 0;
  w += sldns_str_print(s, slen, "%s", pref);
  w += print_hex_buf(s, slen, *d, *dlen);
  *d += *dlen;
  *dlen = 0;
  return w;
}

int sldns_wire2str_pkt_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen)
{
  int w = 0, comprloop = 0;
  unsigned qdcount, ancount, nscount, arcount, i;
  uint8_t* pkt = *d;
  size_t pktlen = *dlen;
  if(*dlen >= LDNS_HEADER_SIZE) {
    qdcount = (unsigned)LDNS_QDCOUNT(*d);
    ancount = (unsigned)LDNS_ANCOUNT(*d);
    nscount = (unsigned)LDNS_NSCOUNT(*d);
    arcount = (unsigned)LDNS_ARCOUNT(*d);
  } else {
    qdcount = ancount = nscount = arcount = 0;
  }
  w += sldns_wire2str_header_scan(d, dlen, s, slen);
  w += sldns_str_print(s, slen, "\n");
  w += sldns_str_print(s, slen, ";; QUESTION SECTION:\n");
  for(i=0; i<qdcount; i++) {
    w += sldns_wire2str_rrquestion_scan(d, dlen, s, slen,
      pkt, pktlen, &comprloop);
    if(!*dlen) break;
  }
  w += sldns_str_print(s, slen, "\n");
  w += sldns_str_print(s, slen, ";; ANSWER SECTION:\n");
  for(i=0; i<ancount; i++) {
    w += sldns_wire2str_rr_scan(d, dlen, s, slen, pkt, pktlen, &comprloop);
    if(!*dlen) break;
  }
  w += sldns_str_print(s, slen, "\n");
  w += sldns_str_print(s, slen, ";; AUTHORITY SECTION:\n");
  for(i=0; i<nscount; i++) {
    w += sldns_wire2str_rr_scan(d, dlen, s, slen, pkt, pktlen, &comprloop);
    if(!*dlen) break;
  }
  w += sldns_str_print(s, slen, "\n");
  w += sldns_str_print(s, slen, ";; ADDITIONAL SECTION:\n");
  for(i=0; i<arcount; i++) {
    w += sldns_wire2str_rr_scan(d, dlen, s, slen, pkt, pktlen, &comprloop);
    if(!*dlen) break;
  }
  /* other fields: WHEN(time), SERVER(IP) not available here. */
  w += sldns_str_print(s, slen, ";; MSG SIZE  rcvd: %d\n", (int)pktlen);
  if(*dlen > 0) {
    w += print_remainder_hex(";; trailing garbage 0x",
      d, dlen, s, slen);
    w += sldns_str_print(s, slen, "\n");
  }
  return w;
}

/** scan type, class and ttl and printout, for rr */
static int sldns_rr_tcttl_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w = 0;
  uint16_t t, c;
  uint32_t ttl;
  if(*dl < 8) {
    if(*dl < 4)
      return w + print_remainder_hex("; Error malformed 0x",
        d, dl, s, sl);
    /* these print values or 0x.. if none left */
    t = sldns_read_uint16(*d);
    c = sldns_read_uint16((*d)+2);
    (*d)+=4;
    (*dl)-=4;
    w += sldns_wire2str_class_print(s, sl, c);
    w += sldns_str_print(s, sl, "\t");
    w += sldns_wire2str_type_print(s, sl, t);
    if(*dl == 0)
      return w + sldns_str_print(s, sl, "; Error no ttl");
    return w + print_remainder_hex(
      "; Error malformed ttl 0x", d, dl, s, sl);
  }
  t = sldns_read_uint16(*d);
  c = sldns_read_uint16((*d)+2);
  ttl = sldns_read_uint32((*d)+4);
  (*d)+=8;
  (*dl)-=8;
  w += sldns_str_print(s, sl, "%lu\t", (unsigned long)ttl);
  w += sldns_wire2str_class_print(s, sl, c);
  w += sldns_str_print(s, sl, "\t");
  w += sldns_wire2str_type_print(s, sl, t);
  return w;
}

int sldns_wire2str_rr_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen,
  uint8_t* pkt, size_t pktlen, int* comprloop)
{
  int w = 0;
  uint8_t* rr = *d;
  size_t rrlen = *dlen, dname_off, rdlen, ordlen;
  uint16_t rrtype = 0;
  
  if(*dlen >= 3 && (*d)[0]==0 &&
    sldns_read_uint16((*d)+1)==LDNS_RR_TYPE_OPT) {
    /* perform EDNS OPT processing */
    return sldns_wire2str_edns_scan(d, dlen, s, slen, pkt, pktlen);
  }

  /* try to scan the rdata with pretty-printing, but if that fails, then
   * scan the rdata as an unknown RR type */
  w += sldns_wire2str_dname_scan(d, dlen, s, slen, pkt, pktlen, comprloop);
  w += sldns_str_print(s, slen, "\t");
  dname_off = rrlen-(*dlen);
  if(*dlen == 4) {
    /* like a question-RR */
    uint16_t t = sldns_read_uint16(*d);
    uint16_t c = sldns_read_uint16((*d)+2);
    (*d)+=4;
    (*dlen)-=4;
    w += sldns_wire2str_class_print(s, slen, c);
    w += sldns_str_print(s, slen, "\t");
    w += sldns_wire2str_type_print(s, slen, t);
    w += sldns_str_print(s, slen, " ; Error no ttl,rdata\n");
    return w;
  }
  if(*dlen < 8) {
    if(*dlen == 0)
      return w + sldns_str_print(s, slen, ";Error missing RR\n");
    w += print_remainder_hex(";Error partial RR 0x", d, dlen, s, slen);
    return w + sldns_str_print(s, slen, "\n");
  }
  rrtype = sldns_read_uint16(*d);
  w += sldns_rr_tcttl_scan(d, dlen, s, slen);
  w += sldns_str_print(s, slen, "\t");

  /* rdata */
  if(*dlen < 2) {
    if(*dlen == 0)
      return w + sldns_str_print(s, slen, ";Error missing rdatalen\n");
    w += print_remainder_hex(";Error missing rdatalen 0x",
      d, dlen, s, slen);
    return w + sldns_str_print(s, slen, "\n");
  }
  rdlen = sldns_read_uint16(*d);
  ordlen = rdlen;
  (*d)+=2;
  (*dlen)-=2;
  if(*dlen < rdlen) {
    w += sldns_str_print(s, slen, "\\# %u ", (unsigned)rdlen);
    if(*dlen == 0)
      return w + sldns_str_print(s, slen, ";Error missing rdata\n");
    w += print_remainder_hex(";Error partial rdata 0x", d, dlen, s, slen);
    return w + sldns_str_print(s, slen, "\n");
  }
  w += sldns_wire2str_rdata_scan(d, &rdlen, s, slen, rrtype, pkt, pktlen,
    comprloop);
  (*dlen) -= (ordlen-rdlen);

  /* default comment */
  w += sldns_wire2str_rr_comment_print(s, slen, rr, rrlen, dname_off,
    rrtype);
  w += sldns_str_print(s, slen, "\n");
  return w;
}

int sldns_wire2str_rrquestion_scan(uint8_t** d, size_t* dlen, char** s,
  size_t* slen, uint8_t* pkt, size_t pktlen, int* comprloop)
{
  int w = 0;
  uint16_t t, c;
  w += sldns_wire2str_dname_scan(d, dlen, s, slen, pkt, pktlen, comprloop);
  w += sldns_str_print(s, slen, "\t");
  if(*dlen < 4) {
    if(*dlen == 0)
      return w + sldns_str_print(s, slen, "Error malformed\n");
    w += print_remainder_hex("Error malformed 0x", d, dlen, s, slen);
    return w + sldns_str_print(s, slen, "\n");
  }
  t = sldns_read_uint16(*d);
  c = sldns_read_uint16((*d)+2);
  (*d)+=4;
  (*dlen)-=4;
  w += sldns_wire2str_class_print(s, slen, c);
  w += sldns_str_print(s, slen, "\t");
  w += sldns_wire2str_type_print(s, slen, t);
  w += sldns_str_print(s, slen, "\n");
  return w;
}

int sldns_wire2str_rr_unknown_scan(uint8_t** d, size_t* dlen, char** s,
  size_t* slen, uint8_t* pkt, size_t pktlen, int* comprloop)
{
  size_t rdlen, ordlen;
  int w = 0;
  w += sldns_wire2str_dname_scan(d, dlen, s, slen, pkt, pktlen, comprloop);
  w += sldns_str_print(s, slen, "\t");
  w += sldns_rr_tcttl_scan(d, dlen, s, slen);
  w += sldns_str_print(s, slen, "\t");
  if(*dlen < 2) {
    if(*dlen == 0)
      return w + sldns_str_print(s, slen, ";Error missing rdatalen\n");
    w += print_remainder_hex(";Error missing rdatalen 0x",
      d, dlen, s, slen);
    return w + sldns_str_print(s, slen, "\n");
  }
  rdlen = sldns_read_uint16(*d);
  ordlen = rdlen;
  (*d) += 2;
  (*dlen) -= 2;
  if(*dlen < rdlen) {
    w += sldns_str_print(s, slen, "\\# %u ", (unsigned)rdlen);
    if(*dlen == 0)
      return w + sldns_str_print(s, slen, ";Error missing rdata\n");
    w += print_remainder_hex(";Error partial rdata 0x", d, dlen, s, slen);
    return w + sldns_str_print(s, slen, "\n");
  }
  w += sldns_wire2str_rdata_unknown_scan(d, &rdlen, s, slen);
  (*dlen) -= (ordlen-rdlen);
  w += sldns_str_print(s, slen, "\n");
  return w;
}

/** print rr comment for type DNSKEY */
static int rr_comment_dnskey(char** s, size_t* slen, uint8_t* rr,
  size_t rrlen, size_t dname_off)
{
  size_t rdlen;
  uint8_t* rdata;
  int flags, w = 0;
  if(rrlen < dname_off + 10) return 0;
  rdlen = sldns_read_uint16(rr+dname_off+8);
  if(rrlen < dname_off + 10 + rdlen) return 0;
  if(rdlen < 2) return 0;
  rdata = rr + dname_off + 10;
  flags = (int)sldns_read_uint16(rdata);
  w += sldns_str_print(s, slen, " ;{");

  /* id */
  w += sldns_str_print(s, slen, "id = %u",
    sldns_calc_keytag_raw(rdata, rdlen));

  /* flags */
  if((flags&LDNS_KEY_ZONE_KEY)) {
    if((flags&LDNS_KEY_SEP_KEY))
      w += sldns_str_print(s, slen, " (ksk)");
    else  w += sldns_str_print(s, slen, " (zsk)");
  }

  /* keysize */
  if(rdlen > 4) {
    w += sldns_str_print(s, slen, ", ");
    w += sldns_str_print(s, slen, "size = %db",
      (int)sldns_rr_dnskey_key_size_raw(
      (unsigned char*)rdata+4, rdlen-4, (int)(rdata[3])));
  }

  w += sldns_str_print(s, slen, "}");
  return w;
}

/** print rr comment for type RRSIG */
static int rr_comment_rrsig(char** s, size_t* slen, uint8_t* rr,
  size_t rrlen, size_t dname_off)
{
  size_t rdlen;
  uint8_t* rdata;
  if(rrlen < dname_off + 10) return 0;
  rdlen = sldns_read_uint16(rr+dname_off+8);
  if(rrlen < dname_off + 10 + rdlen) return 0;
  rdata = rr + dname_off + 10;
  if(rdlen < 18) return 0;
  return sldns_str_print(s, slen, " ;{id = %d}",
    (int)sldns_read_uint16(rdata+16));
}

/** print rr comment for type NSEC3 */
static int rr_comment_nsec3(char** s, size_t* slen, uint8_t* rr,
  size_t rrlen, size_t dname_off)
{
  size_t rdlen;
  uint8_t* rdata;
  int w = 0;
  if(rrlen < dname_off + 10) return 0;
  rdlen = sldns_read_uint16(rr+dname_off+8);
  if(rrlen < dname_off + 10 + rdlen) return 0;
  rdata = rr + dname_off + 10;
  if(rdlen < 2) return 0;
  if((rdata[1] & LDNS_NSEC3_VARS_OPTOUT_MASK))
    w += sldns_str_print(s, slen, " ;{flags: optout}");
  return w;
}

int sldns_wire2str_rr_comment_print(char** s, size_t* slen, uint8_t* rr,
  size_t rrlen, size_t dname_off, uint16_t rrtype)
{
  if(rrtype == LDNS_RR_TYPE_DNSKEY) {
    return rr_comment_dnskey(s, slen, rr, rrlen, dname_off);
  } else if(rrtype == LDNS_RR_TYPE_RRSIG) {
    return rr_comment_rrsig(s, slen, rr, rrlen, dname_off);
  } else if(rrtype == LDNS_RR_TYPE_NSEC3) {
    return rr_comment_nsec3(s, slen, rr, rrlen, dname_off);
  }
  return 0;
}

int sldns_wire2str_header_scan(uint8_t** d, size_t* dlen, char** s,
  size_t* slen)
{
  int w = 0;
  int opcode, rcode;
  w += sldns_str_print(s, slen, ";; ->>HEADER<<- ");
  if(*dlen == 0)
    return w+sldns_str_print(s, slen, "Error empty packet");
  if(*dlen < 4)
    return w+print_remainder_hex("Error header too short 0x", d, dlen, s, slen);
  opcode = (int)LDNS_OPCODE_WIRE(*d);
  rcode = (int)LDNS_RCODE_WIRE(*d);
  w += sldns_str_print(s, slen, "opcode: ");
  w += sldns_wire2str_opcode_print(s, slen, opcode);
  w += sldns_str_print(s, slen, ", ");
  w += sldns_str_print(s, slen, "rcode: ");
  w += sldns_wire2str_rcode_print(s, slen, rcode);
  w += sldns_str_print(s, slen, ", ");
  w += sldns_str_print(s, slen, "id: %d\n", (int)LDNS_ID_WIRE(*d));
  w += sldns_str_print(s, slen, ";; flags:");
  if(LDNS_QR_WIRE(*d)) w += sldns_str_print(s, slen, " qr");
  if(LDNS_AA_WIRE(*d)) w += sldns_str_print(s, slen, " aa");
  if(LDNS_TC_WIRE(*d)) w += sldns_str_print(s, slen, " tc");
  if(LDNS_RD_WIRE(*d)) w += sldns_str_print(s, slen, " rd");
  if(LDNS_CD_WIRE(*d)) w += sldns_str_print(s, slen, " cd");
  if(LDNS_RA_WIRE(*d)) w += sldns_str_print(s, slen, " ra");
  if(LDNS_AD_WIRE(*d)) w += sldns_str_print(s, slen, " ad");
  if(LDNS_Z_WIRE(*d))  w += sldns_str_print(s, slen, " z");
  w += sldns_str_print(s, slen, " ; ");
  if(*dlen < LDNS_HEADER_SIZE)
    return w+print_remainder_hex("Error header too short 0x", d, dlen, s, slen);
  w += sldns_str_print(s, slen, "QUERY: %d, ", (int)LDNS_QDCOUNT(*d));
  w += sldns_str_print(s, slen, "ANSWER: %d, ", (int)LDNS_ANCOUNT(*d));
  w += sldns_str_print(s, slen, "AUTHORITY: %d, ", (int)LDNS_NSCOUNT(*d));
  w += sldns_str_print(s, slen, "ADDITIONAL: %d ", (int)LDNS_ARCOUNT(*d));
  *d += LDNS_HEADER_SIZE;
  *dlen -= LDNS_HEADER_SIZE;
  return w;
}

int sldns_wire2str_rdata_scan(uint8_t** d, size_t* dlen, char** s,
  size_t* slen, uint16_t rrtype, uint8_t* pkt, size_t pktlen,
  int* comprloop)
{
  /* try to prettyprint, but if that fails, use unknown format */
  uint8_t* origd = *d;
  char* origs = *s;
  size_t origdlen = *dlen, origslen = *slen;
  size_t r_cnt, r_max;
  sldns_rdf_type rdftype;
  int w = 0, n;

  const sldns_rr_descriptor *desc = sldns_rr_descript(rrtype);
  if(!desc) /* unknown format */
    return sldns_wire2str_rdata_unknown_scan(d, dlen, s, slen);
  /* dlen equals the rdatalen for the rdata */

  r_max = sldns_rr_descriptor_maximum(desc);
  for(r_cnt=0; r_cnt < r_max; r_cnt++) {
    if(*dlen == 0) {
      if(r_cnt < sldns_rr_descriptor_minimum(desc))
        goto failed;
      break; /* nothing more to print */
    }
    rdftype = sldns_rr_descriptor_field_type(desc, r_cnt);
    if(r_cnt != 0)
      w += sldns_str_print(s, slen, " ");
    n = sldns_wire2str_rdf_scan(d, dlen, s, slen, rdftype,
      pkt, pktlen, comprloop);
    if(n == -1) {
    failed:
      /* failed, use unknown format */
      *d = origd; *s = origs;
      *dlen = origdlen; *slen = origslen;
      return sldns_wire2str_rdata_unknown_scan(d, dlen,
        s, slen);
    }
    w += n;
  }
  if(*dlen != 0) {
    goto failed;
  }
  return w;
}

int sldns_wire2str_rdata_unknown_scan(uint8_t** d, size_t* dlen, char** s,
  size_t* slen)
{
  int w = 0;

  /* print length */
  w += sldns_str_print(s, slen, "\\# %u", (unsigned)*dlen);

  /* print rdlen in hex */
  if(*dlen != 0)
    w += sldns_str_print(s, slen, " ");
  w += print_hex_buf(s, slen, *d, *dlen);
  (*d) += *dlen;
  (*dlen) = 0;
  return w;
}

/** print and escape one character for a domain dname */
static int dname_char_print(char** s, size_t* slen, uint8_t c)
{
  if(c == '.' || c == ';' || c == '(' || c == ')' || c == '\\')
    return sldns_str_print(s, slen, "\\%c", c);
  else if(!(isascii((unsigned char)c) && isgraph((unsigned char)c)))
    return sldns_str_print(s, slen, "\\%03u", (unsigned)c);
  /* plain printout */
  if(*slen) {
    **s = (char)c;
    (*s)++;
    (*slen)--;
  }
  return 1;
}

int sldns_wire2str_dname_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen,
  uint8_t* pkt, size_t pktlen, int* comprloop)
{
  int w = 0;
  /* spool labels onto the string, use compression if its there */
  uint8_t* pos = *d;
  unsigned i, counter=0;
  unsigned maxcompr = MAX_COMPRESS_PTRS; /* loop detection, max compr ptrs */
  int in_buf = 1;
  size_t dname_len = 0;
  if(comprloop) {
    if(*comprloop != 0)
      maxcompr = 30; /* for like ipv6 reverse name, per label */
    if(*comprloop > 4)
      maxcompr = 4; /* just don't want to spend time, any more */
  }
  if(*dlen == 0) return sldns_str_print(s, slen, "ErrorMissingDname");
  if(*pos == 0) {
    (*d)++;
    (*dlen)--;
    return sldns_str_print(s, slen, ".");
  }
  while((!pkt || pos < pkt+pktlen) && *pos) {
    /* read label length */
    uint8_t labellen = *pos++;
    if(in_buf) { (*d)++; (*dlen)--; }

    /* find out what sort of label we have */
    if((labellen&0xc0) == 0xc0) {
      /* compressed */
      uint16_t target = 0;
      if(in_buf && *dlen == 0)
        return w + sldns_str_print(s, slen,
          "ErrorPartialDname");
      else if(!in_buf && pos+1 > pkt+pktlen)
        return w + sldns_str_print(s, slen,
          "ErrorPartialDname");
      target = ((labellen&0x3f)<<8) | *pos;
      if(in_buf) { (*d)++; (*dlen)--; }
      /* move to target, if possible */
      if(!pkt || target >= pktlen)
        return w + sldns_str_print(s, slen,
          "ErrorComprPtrOutOfBounds");
      if(counter++ > maxcompr) {
        if(comprloop && *comprloop < 10)
          (*comprloop)++;
        return w + sldns_str_print(s, slen,
          "ErrorComprPtrLooped");
      }
      in_buf = 0;
      pos = pkt+target;
      continue;
    } else if((labellen&0xc0)) {
      /* notimpl label type */
      w += sldns_str_print(s, slen,
        "ErrorLABELTYPE%xIsUnknown",
        (int)(labellen&0xc0));
      return w;
    }

    /* spool label characters, end with '.' */
    if(in_buf && *dlen < (size_t)labellen)
      labellen = (uint8_t)*dlen;
    else if(!in_buf && pos+(size_t)labellen > pkt+pktlen)
      labellen = (uint8_t)(pkt + pktlen - pos);
    dname_len += ((size_t)labellen)+1;
    if(dname_len > LDNS_MAX_DOMAINLEN) {
      /* dname_len counts the uncompressed length we have
       * seen so far, and the domain name has become too
       * long, prevent the loop from printing overly long
       * content. */
      w += sldns_str_print(s, slen,
        "ErrorDomainNameTooLong");
      return w;
    }
    for(i=0; i<(unsigned)labellen; i++) {
      w += dname_char_print(s, slen, *pos++);
    }
    if(in_buf) {
      (*d) += labellen;
      (*dlen) -= labellen;
      if(*dlen == 0) break;
    }
    w += sldns_str_print(s, slen, ".");
  }
  /* skip over final root label */
  if(in_buf && *dlen > 0) { (*d)++; (*dlen)--; }
  /* in case we printed no labels, terminate dname */
  if(w == 0) w += sldns_str_print(s, slen, ".");
  return w;
}

int sldns_wire2str_opcode_print(char** s, size_t* slen, int opcode)
{
  sldns_lookup_table *lt = sldns_lookup_by_id(sldns_opcodes, opcode);
  if (lt && lt->name) {
    return sldns_str_print(s, slen, "%s", lt->name);
  }
  return sldns_str_print(s, slen, "OPCODE%u", (unsigned)opcode);
}

int sldns_wire2str_rcode_print(char** s, size_t* slen, int rcode)
{
  sldns_lookup_table *lt = sldns_lookup_by_id(sldns_rcodes, rcode);
  if (lt && lt->name) {
    return sldns_str_print(s, slen, "%s", lt->name);
  }
  return sldns_str_print(s, slen, "RCODE%u", (unsigned)rcode);
}

int sldns_wire2str_class_print(char** s, size_t* slen, uint16_t rrclass)
{
  sldns_lookup_table *lt = sldns_lookup_by_id(sldns_rr_classes,
    (int)rrclass);
  if (lt && lt->name) {
    return sldns_str_print(s, slen, "%s", lt->name);
  }
  return sldns_str_print(s, slen, "CLASS%u", (unsigned)rrclass);
}

int sldns_wire2str_type_print(char** s, size_t* slen, uint16_t rrtype)
{
  const sldns_rr_descriptor *descriptor = sldns_rr_descript(rrtype);
  if (descriptor && descriptor->_name) {
    return sldns_str_print(s, slen, "%s", descriptor->_name);
  }
  return sldns_str_print(s, slen, "TYPE%u", (unsigned)rrtype);
}

int sldns_wire2str_edns_option_code_print(char** s, size_t* slen,
  uint16_t opcode)
{
  sldns_lookup_table *lt = sldns_lookup_by_id(sldns_edns_options,
    (int)opcode);
  if (lt && lt->name) {
    return sldns_str_print(s, slen, "%s", lt->name);
  }
  return sldns_str_print(s, slen, "OPT%u", (unsigned)opcode);
}

int sldns_wire2str_class_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen)
{
  uint16_t c;
  if(*dlen == 0) return 0;
  if(*dlen < 2) return print_remainder_hex("Error malformed 0x", d, dlen, s, slen);
  c = sldns_read_uint16(*d);
  (*d)+=2;
  (*dlen)-=2;
  return sldns_wire2str_class_print(s, slen, c);
}

int sldns_wire2str_type_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen)
{
  uint16_t t;
  if(*dlen == 0) return 0;
  if(*dlen < 2) return print_remainder_hex("Error malformed 0x", d, dlen, s, slen);
  t = sldns_read_uint16(*d);
  (*d)+=2;
  (*dlen)-=2;
  return sldns_wire2str_type_print(s, slen, t);
}

int sldns_wire2str_ttl_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen)
{
  uint32_t ttl;
  if(*dlen == 0) return 0;
  if(*dlen < 4) return print_remainder_hex("Error malformed 0x", d, dlen, s, slen);
  ttl = sldns_read_uint32(*d);
  (*d)+=4;
  (*dlen)-=4;
  return sldns_str_print(s, slen, "%u", (unsigned)ttl);
}

static int
sldns_print_svcparamkey(char** s, size_t* slen, uint16_t svcparamkey)
{
  if (svcparamkey < SVCPARAMKEY_COUNT) {
    return sldns_str_print(s, slen, "%s", svcparamkey_strs[svcparamkey]);
  }
  else {
    return sldns_str_print(s, slen, "key%d", (int)svcparamkey);
  }
}

static int sldns_wire2str_svcparam_port2str(char** s,
  size_t* slen, uint16_t data_len, uint8_t* data)
{
  int w = 0;

  if (data_len != 2)
    return -1; /* wireformat error, a short is 2 bytes */
  w = sldns_str_print(s, slen, "=%d", (int)sldns_read_uint16(data));

  return w;
}

static int sldns_wire2str_svcparam_ipv4hint2str(char** s,
  size_t* slen, uint16_t data_len, uint8_t* data)
{
  char ip_str[INET_ADDRSTRLEN + 1];

  int w = 0;

  assert(data_len > 0);

  if ((data_len % LDNS_IP4ADDRLEN) == 0) {
    if (inet_ntop(AF_INET, data, ip_str, sizeof(ip_str)) == NULL)
      return -1; /* wireformat error, incorrect size or inet family */

    w += sldns_str_print(s, slen, "=%s", ip_str);
    data += LDNS_IP4ADDRLEN;

    while ((data_len -= LDNS_IP4ADDRLEN) > 0) {
      if (inet_ntop(AF_INET, data, ip_str, sizeof(ip_str)) == NULL)
        return -1; /* wireformat error, incorrect size or inet family */

      w += sldns_str_print(s, slen, ",%s", ip_str);
      data += LDNS_IP4ADDRLEN;
    }
  } else
    return -1;

  return w;
}

static int sldns_wire2str_svcparam_ipv6hint2str(char** s,
  size_t* slen, uint16_t data_len, uint8_t* data)
{
  char ip_str[INET6_ADDRSTRLEN + 1];

  int w = 0;

  assert(data_len > 0);

  if ((data_len % LDNS_IP6ADDRLEN) == 0) {
    if (inet_ntop(AF_INET6, data, ip_str, sizeof(ip_str)) == NULL)
      return -1; /* wireformat error, incorrect size or inet family */

    w += sldns_str_print(s, slen, "=%s", ip_str);
    data += LDNS_IP6ADDRLEN;

    while ((data_len -= LDNS_IP6ADDRLEN) > 0) {
      if (inet_ntop(AF_INET6, data, ip_str, sizeof(ip_str)) == NULL)
        return -1; /* wireformat error, incorrect size or inet family */

      w += sldns_str_print(s, slen, ",%s", ip_str);
      data += LDNS_IP6ADDRLEN;
    }
  } else
    return -1;

  return w;
}

static int sldns_wire2str_svcparam_mandatory2str(char** s,
  size_t* slen, uint16_t data_len, uint8_t* data)
{
  int w = 0;

  assert(data_len > 0);

  if (data_len % sizeof(uint16_t))
    return -1; /* wireformat error, data_len must be multiple of shorts */
  w += sldns_str_print(s, slen, "=");
  w += sldns_print_svcparamkey(s, slen, sldns_read_uint16(data));
  data += 2;

  while ((data_len -= sizeof(uint16_t))) {
    w += sldns_str_print(s, slen, ",");
    w += sldns_print_svcparamkey(s, slen, sldns_read_uint16(data));
    data += 2;
  }

  return w;
}

static int sldns_wire2str_svcparam_alpn2str(char** s,
  size_t* slen, uint16_t data_len, uint8_t* data)
{
  uint8_t *dp = (void *)data;
  int w = 0;

  assert(data_len > 0); /* Guaranteed by sldns_wire2str_svcparam_scan */

  w += sldns_str_print(s, slen, "=\"");
  while (data_len) {
    /* alpn is list of length byte (str_len) followed by a string of that size */
    uint8_t i, str_len = *dp++;

    if (str_len > --data_len)
      return -1;

    for (i = 0; i < str_len; i++) {
      if (dp[i] == '"' || dp[i] == '\\')
        w += sldns_str_print(s, slen, "\\\\\\%c", dp[i]);

      else if (dp[i] == ',')
        w += sldns_str_print(s, slen, "\\\\%c", dp[i]);

      else if (!isprint(dp[i]))
        w += sldns_str_print(s, slen, "\\%03u", (unsigned) dp[i]);

      else
        w += sldns_str_print(s, slen, "%c", dp[i]);
    }
    dp += str_len;
    if ((data_len -= str_len))
      w += sldns_str_print(s, slen, "%s", ",");
  }
  w += sldns_str_print(s, slen, "\"");
  
  return w;
}

static int sldns_wire2str_svcparam_ech2str(char** s,
  size_t* slen, uint16_t data_len, uint8_t* data)
{
  int size;
  int w = 0;

  assert(data_len > 0); /* Guaranteed by sldns_wire2str_svcparam_scan */

  w += sldns_str_print(s, slen, "=\"");

  if ((size = sldns_b64_ntop(data, data_len, *s, *slen)) < 0)
    return -1;

  (*s) += size;
  (*slen) -= size;

  w += sldns_str_print(s, slen, "\"");  

  return w + size;
}

int sldns_wire2str_svcparam_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen)
{
  uint8_t ch;
  uint16_t svcparamkey, data_len;
  int written_chars = 0;
  int r, i;

  /* verify that we have enough data to read svcparamkey and data_len */
  if(*dlen < 4)
    return -1;

  svcparamkey = sldns_read_uint16(*d);
  data_len = sldns_read_uint16(*d+2);
  *d    += 4;
  *dlen -= 4;

  /* verify that we have data_len data */
  if (data_len > *dlen)
    return -1; 

  written_chars += sldns_print_svcparamkey(s, slen, svcparamkey);
  if (!data_len) {

    /* Some SvcParams MUST have values */
    switch (svcparamkey) {
    case SVCB_KEY_ALPN:
    case SVCB_KEY_PORT:
    case SVCB_KEY_IPV4HINT:
    case SVCB_KEY_IPV6HINT:
    case SVCB_KEY_MANDATORY:
      return -1;
    default:
      return written_chars;
    }
  }

  switch (svcparamkey) {
  case SVCB_KEY_PORT:
    r = sldns_wire2str_svcparam_port2str(s, slen, data_len, *d);
    break;
  case SVCB_KEY_IPV4HINT:
    r = sldns_wire2str_svcparam_ipv4hint2str(s, slen, data_len, *d);
    break;
  case SVCB_KEY_IPV6HINT:
    r = sldns_wire2str_svcparam_ipv6hint2str(s, slen, data_len, *d);
    break;
  case SVCB_KEY_MANDATORY:
    r = sldns_wire2str_svcparam_mandatory2str(s, slen, data_len, *d);
    break;
  case SVCB_KEY_NO_DEFAULT_ALPN:
    return -1;  /* wireformat error, should not have a value */
  case SVCB_KEY_ALPN:
    r = sldns_wire2str_svcparam_alpn2str(s, slen, data_len, *d);
    break;
  case SVCB_KEY_ECH:
    r = sldns_wire2str_svcparam_ech2str(s, slen, data_len, *d);
    break;
  default:
    r = sldns_str_print(s, slen, "=\"");

    for (i = 0; i < data_len; i++) {
      ch = (*d)[i];

      if (ch == '"' || ch == '\\')
        r += sldns_str_print(s, slen, "\\%c", ch);

      else if (!isprint(ch))
        r += sldns_str_print(s, slen, "\\%03u", (unsigned) ch);

      else
        r += sldns_str_print(s, slen, "%c", ch);

    }
    r += sldns_str_print(s, slen, "\"");
    break;
  }
  if (r <= 0)
    return -1; /* wireformat error */
  
  written_chars += r;
  *d    += data_len;
  *dlen -= data_len;
  return written_chars;
}

int sldns_wire2str_rdf_scan(uint8_t** d, size_t* dlen, char** s, size_t* slen,
  int rdftype, uint8_t* pkt, size_t pktlen, int* comprloop)
{
  if(*dlen == 0) return 0;
  switch(rdftype) {
  case LDNS_RDF_TYPE_NONE:
    return 0;
  case LDNS_RDF_TYPE_DNAME:
    return sldns_wire2str_dname_scan(d, dlen, s, slen, pkt, pktlen, comprloop);
  case LDNS_RDF_TYPE_INT8:
    return sldns_wire2str_int8_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_INT16:
    return sldns_wire2str_int16_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_INT32:
    return sldns_wire2str_int32_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_PERIOD:
    return sldns_wire2str_period_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_TSIGTIME:
    return sldns_wire2str_tsigtime_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_A:
    return sldns_wire2str_a_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_AAAA:
    return sldns_wire2str_aaaa_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_STR:
    return sldns_wire2str_str_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_APL:
    return sldns_wire2str_apl_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_B32_EXT:
    return sldns_wire2str_b32_ext_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_B64:
    return sldns_wire2str_b64_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_HEX:
    return sldns_wire2str_hex_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_NSEC:
    return sldns_wire2str_nsec_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_NSEC3_SALT:
    return sldns_wire2str_nsec3_salt_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_TYPE:
    return sldns_wire2str_type_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_CLASS:
    return sldns_wire2str_class_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_CERT_ALG:
    return sldns_wire2str_cert_alg_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_ALG:
    return sldns_wire2str_alg_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_UNKNOWN:
    return sldns_wire2str_unknown_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_TIME:
    return sldns_wire2str_time_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_LOC:
    return sldns_wire2str_loc_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_WKS:
  case LDNS_RDF_TYPE_SERVICE:
    return sldns_wire2str_wks_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_NSAP:
    return sldns_wire2str_nsap_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_ATMA:
    return sldns_wire2str_atma_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_IPSECKEY:
    return sldns_wire2str_ipseckey_scan(d, dlen, s, slen, pkt,
      pktlen, comprloop);
  case LDNS_RDF_TYPE_HIP:
    return sldns_wire2str_hip_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_INT16_DATA:
    return sldns_wire2str_int16_data_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_NSEC3_NEXT_OWNER:
    return sldns_wire2str_b32_ext_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_ILNP64:
    return sldns_wire2str_ilnp64_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_EUI48:
    return sldns_wire2str_eui48_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_EUI64:
    return sldns_wire2str_eui64_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_TAG:
    return sldns_wire2str_tag_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_LONG_STR:
    return sldns_wire2str_long_str_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_SVCPARAM:
    return sldns_wire2str_svcparam_scan(d, dlen, s, slen);
  case LDNS_RDF_TYPE_TSIGERROR:
    return sldns_wire2str_tsigerror_scan(d, dlen, s, slen);
  }
  /* unknown rdf type */
  return -1;
}

int sldns_wire2str_int8_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  if(*dl < 1) return -1;
  w = sldns_str_print(s, sl, "%u", (unsigned)**d);
  (*d)++;
  (*dl)--;
  return w;
}

int sldns_wire2str_int16_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  if(*dl < 2) return -1;
  w = sldns_str_print(s, sl, "%lu", (unsigned long)sldns_read_uint16(*d));
  (*d)+=2;
  (*dl)-=2;
  return w;
}

int sldns_wire2str_int32_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  if(*dl < 4) return -1;
  w = sldns_str_print(s, sl, "%lu", (unsigned long)sldns_read_uint32(*d));
  (*d)+=4;
  (*dl)-=4;
  return w;
}

int sldns_wire2str_period_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  if(*dl < 4) return -1;
  w = sldns_str_print(s, sl, "%u", (unsigned)sldns_read_uint32(*d));
  (*d)+=4;
  (*dl)-=4;
  return w;
}

int sldns_wire2str_tsigtime_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  /* tsigtime is 48 bits network order unsigned integer */
  int w;
  uint64_t tsigtime = 0;
  uint64_t d0, d1, d2, d3, d4, d5;
  if(*dl < 6) return -1;
  d0 = (*d)[0]; /* cast to uint64 for shift operations */
  d1 = (*d)[1];
  d2 = (*d)[2];
  d3 = (*d)[3];
  d4 = (*d)[4];
  d5 = (*d)[5];
  tsigtime = (d0<<40) | (d1<<32) | (d2<<24) | (d3<<16) | (d4<<8) | d5;
#ifndef USE_WINSOCK
  w = sldns_str_print(s, sl, "%llu", (long long)tsigtime);
#else
  w = sldns_str_print(s, sl, "%I64u", (long long)tsigtime);
#endif
  (*d)+=6;
  (*dl)-=6;
  return w;
}

int sldns_wire2str_a_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  char buf[32];
  int w;
  if(*dl < 4) return -1;
  if(!inet_ntop(AF_INET, *d, buf, (socklen_t)sizeof(buf)))
    return -1;
  w = sldns_str_print(s, sl, "%s", buf);
  (*d)+=4;
  (*dl)-=4;
  return w;
}

int sldns_wire2str_aaaa_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
#ifdef AF_INET6
  char buf[64];
  int w;
  if(*dl < 16) return -1;
  if(!inet_ntop(AF_INET6, *d, buf, (socklen_t)sizeof(buf)))
    return -1;
  w = sldns_str_print(s, sl, "%s", buf);
  (*d)+=16;
  (*dl)-=16;
  return w;
#else
  return -1;
#endif
}

/** printout escaped TYPE_STR character */
static int str_char_print(char** s, size_t* sl, uint8_t c)
{
  if(isprint((unsigned char)c) || c == '\t') {
    if(c == '\"' || c == '\\')
      return sldns_str_print(s, sl, "\\%c", c);
    if(*sl) {
      **s = (char)c;
      (*s)++;
      (*sl)--;
    }
    return 1;
  }
  return sldns_str_print(s, sl, "\\%03u", (unsigned)c);
}

int sldns_wire2str_str_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w = 0;
  size_t i, len;
  if(*dl < 1) return -1;
  len = **d;
  if(*dl < 1+len) return -1;
  (*d)++;
  (*dl)--;
  w += sldns_str_print(s, sl, "\"");
  for(i=0; i<len; i++)
    w += str_char_print(s, sl, (*d)[i]);
  w += sldns_str_print(s, sl, "\"");
  (*d)+=len;
  (*dl)-=len;
  return w;
}

int sldns_wire2str_apl_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int i, w = 0;
  uint16_t family;
  uint8_t negation, prefix, adflength;
  if(*dl < 4) return -1;
  family = sldns_read_uint16(*d);
  prefix = (*d)[2];
  negation = ((*d)[3] & LDNS_APL_NEGATION);
  adflength = ((*d)[3] & LDNS_APL_MASK);
  if(*dl < 4+(size_t)adflength) return -1;
  if(family != LDNS_APL_IP4 && family != LDNS_APL_IP6)
    return -1; /* unknown address family */
  if(negation)
    w += sldns_str_print(s, sl, "!");
  w += sldns_str_print(s, sl, "%u:", (unsigned)family);
  if(family == LDNS_APL_IP4) {
    /* check if prefix <32 ? */
    /* address is variable length 0 - 4 */
    for(i=0; i<4; i++) {
      if(i > 0)
        w += sldns_str_print(s, sl, ".");
      if(i < (int)adflength)
        w += sldns_str_print(s, sl, "%d", (*d)[4+i]);
      else  w += sldns_str_print(s, sl, "0");
    }
  } else if(family == LDNS_APL_IP6) {
    /* check if prefix <128 ? */
    /* address is variable length 0 - 16 */
    for(i=0; i<16; i++) {
      if(i%2 == 0 && i>0)
        w += sldns_str_print(s, sl, ":");
      if(i < (int)adflength)
        w += sldns_str_print(s, sl, "%02x", (*d)[4+i]);
      else  w += sldns_str_print(s, sl, "00");
    }
  }
  w += sldns_str_print(s, sl, "/%u", (unsigned)prefix);
  (*d) += 4+adflength;
  (*dl) -= 4+adflength;
  return w;
}

int sldns_wire2str_b32_ext_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  size_t datalen;
  size_t sz;
  if(*dl < 1) return -1;
  datalen = (*d)[0];
  if(*dl < 1+datalen) return -1;
  sz = sldns_b32_ntop_calculate_size(datalen);
  if(*sl < sz+1) {
    (*d) += datalen+1;
    (*dl) -= (datalen+1);
    return (int)sz; /* out of space really, but would need buffer
      in order to truncate the output */
  }
  sldns_b32_ntop_extended_hex((*d)+1, datalen, *s, *sl);
  (*d) += datalen+1;
  (*dl) -= (datalen+1);
  (*s) += sz;
  (*sl) -= sz;
  return (int)sz;
}

/** scan number of bytes from wire into b64 presentation format */
static int sldns_wire2str_b64_scan_num(uint8_t** d, size_t* dl, char** s,
  size_t* sl, size_t num)
{
  /* b64_ntop_calculate size includes null at the end */
  size_t sz = sldns_b64_ntop_calculate_size(num)-1;
  if(*sl < sz+1) {
    (*d) += num;
    (*dl) -= num;
    return (int)sz; /* out of space really, but would need buffer
      in order to truncate the output */
  }
  sldns_b64_ntop(*d, num, *s, *sl);
  (*d) += num;
  (*dl) -= num;
  (*s) += sz;
  (*sl) -= sz;
  return (int)sz;
}

int sldns_wire2str_b64_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  if(*dl == 0) {
    return sldns_str_print(s, sl, "0");
  }
  return sldns_wire2str_b64_scan_num(d, dl, s, sl, *dl);
}

int sldns_wire2str_hex_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  if(*dl == 0) {
    return sldns_str_print(s, sl, "0");
  }
  return print_remainder_hex("", d, dl, s, sl);
}

int sldns_wire2str_nsec_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  uint8_t* p = *d;
  size_t pl = *dl;
  unsigned i, bit, window, block_len;
  uint16_t t;
  int w = 0;
  
  /* check for errors */
  while(pl) {
    if(pl < 2) return -1;
    block_len = (unsigned)p[1];
    if(pl < 2+block_len) return -1;
    p += block_len+2;
    pl -= block_len+2;
  }

  /* do it */
  p = *d;
  pl = *dl;
  while(pl) {
    if(pl < 2) return -1; /* cannot happen */
    window = (unsigned)p[0];
    block_len = (unsigned)p[1];
    if(pl < 2+block_len) return -1; /* cannot happen */
    p += 2;
    for(i=0; i<block_len; i++) {
      if(p[i] == 0) continue;
      /* base type number for this octet */
      t = ((window)<<8) | (i << 3);
      for(bit=0; bit<8; bit++) {
        if((p[i]&(0x80>>bit))) {
          if(w) w += sldns_str_print(s, sl, " ");
          w += sldns_wire2str_type_print(s, sl,
            t+bit);
        }
      }
    }
    p += block_len;
    pl -= block_len+2;
  }
  (*d) += *dl;
  (*dl) = 0;
  return w;
}

int sldns_wire2str_nsec3_salt_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  size_t salt_len;
  int w;
  if(*dl < 1) return -1;
  salt_len = (size_t)(*d)[0];
  if(*dl < 1+salt_len) return -1;
  (*d)++;
  (*dl)--;
  if(salt_len == 0) {
    return sldns_str_print(s, sl, "-");
  }
  w = print_hex_buf(s, sl, *d, salt_len);
  (*dl)-=salt_len;
  (*d)+=salt_len;
  return w;
}

int sldns_wire2str_cert_alg_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  sldns_lookup_table *lt;
  int data, w;
  if(*dl < 2) return -1;
  data = (int)sldns_read_uint16(*d);
  lt = sldns_lookup_by_id(sldns_cert_algorithms, data);
  if(lt && lt->name)
    w = sldns_str_print(s, sl, "%s", lt->name);
  else  w = sldns_str_print(s, sl, "%d", data);
  (*dl)-=2;
  (*d)+=2;
  return w;
}

int sldns_wire2str_alg_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  /* don't use algorithm mnemonics in the presentation format
   * this kind of got sneaked into the rfc's */
  return sldns_wire2str_int8_scan(d, dl, s, sl);
}

int sldns_wire2str_unknown_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  return sldns_wire2str_rdata_unknown_scan(d, dl, s, sl);
}

int sldns_wire2str_time_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  /* create a YYYYMMDDHHMMSS string if possible */
  struct tm tm;
  char date_buf[16];
  uint32_t t;
  memset(&tm, 0, sizeof(tm));
  if(*dl < 4) return -1;
  t = sldns_read_uint32(*d);
  date_buf[15]=0;
  if(sldns_serial_arithmetics_gmtime_r(t, time(NULL), &tm) &&
    strftime(date_buf, 15, "%Y%m%d%H%M%S", &tm)) {
    (*d) += 4;
    (*dl) -= 4;
    return sldns_str_print(s, sl, "%s", date_buf);
  }
  return -1;
}

static int
loc_cm_print(char** str, size_t* sl, uint8_t mantissa, uint8_t exponent)
{
  int w = 0;
  uint8_t i;
  /* is it 0.<two digits> ? */
  if(exponent < 2) {
    if(exponent == 1)
      mantissa *= 10;
    return sldns_str_print(str, sl, "0.%02ld", (long)mantissa);
  }
  /* always <digit><string of zeros> */
  w += sldns_str_print(str, sl, "%d", (int)mantissa);
  for(i=0; i<exponent-2; i++)
    w += sldns_str_print(str, sl, "0");
  return w;
}

int sldns_wire2str_loc_scan(uint8_t** d, size_t* dl, char** str, size_t* sl)
{
  /* we could do checking (ie degrees < 90 etc)? */
  uint8_t version;
  uint8_t size;
  uint8_t horizontal_precision;
  uint8_t vertical_precision;
  uint32_t longitude;
  uint32_t latitude;
  uint32_t altitude;
  char northerness;
  char easterness;
  uint32_t h;
  uint32_t m;
  double s;
  uint32_t equator = (uint32_t)1 << 31; /* 2**31 */
  int w = 0;

  if(*dl < 16) return -1;
  version = (*d)[0];
  if(version != 0)
    return sldns_wire2str_hex_scan(d, dl, str, sl);
  size = (*d)[1];
  horizontal_precision = (*d)[2];
  vertical_precision = (*d)[3];

  latitude = sldns_read_uint32((*d)+4);
  longitude = sldns_read_uint32((*d)+8);
  altitude = sldns_read_uint32((*d)+12);

  if (latitude > equator) {
    northerness = 'N';
    latitude = latitude - equator;
  } else {
    northerness = 'S';
    latitude = equator - latitude;
  }
  h = latitude / (1000 * 60 * 60);
  latitude = latitude % (1000 * 60 * 60);
  m = latitude / (1000 * 60);
  latitude = latitude % (1000 * 60);
  s = (double) latitude / 1000.0;
  w += sldns_str_print(str, sl, "%02u %02u %06.3f %c ",
    h, m, s, northerness);

  if (longitude > equator) {
    easterness = 'E';
    longitude = longitude - equator;
  } else {
    easterness = 'W';
    longitude = equator - longitude;
  }
  h = longitude / (1000 * 60 * 60);
  longitude = longitude % (1000 * 60 * 60);
  m = longitude / (1000 * 60);
  longitude = longitude % (1000 * 60);
  s = (double) longitude / (1000.0);
  w += sldns_str_print(str, sl, "%02u %02u %06.3f %c ",
    h, m, s, easterness);

  s = ((double) altitude) / 100;
  s -= 100000;

  if(altitude%100 != 0)
    w += sldns_str_print(str, sl, "%.2f", s);
  else
    w += sldns_str_print(str, sl, "%.0f", s);

  w += sldns_str_print(str, sl, "m ");

  w += loc_cm_print(str, sl, (size & 0xf0) >> 4, size & 0x0f);
  w += sldns_str_print(str, sl, "m ");

  w += loc_cm_print(str, sl, (horizontal_precision & 0xf0) >> 4,
    horizontal_precision & 0x0f);
  w += sldns_str_print(str, sl, "m ");

  w += loc_cm_print(str, sl, (vertical_precision & 0xf0) >> 4,
    vertical_precision & 0x0f);
  w += sldns_str_print(str, sl, "m");

  (*d)+=16;
  (*dl)-=16;
  return w;
}

int sldns_wire2str_wks_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  /* protocol, followed by bitmap of services */
  const char* proto_name = NULL;
  struct protoent *protocol;
  struct servent *service;
  uint8_t protocol_nr;
  int bit, port, w = 0;
  size_t i;
  /* we cannot print with strings because they
   * are not portable, the presentation format may
   * not be able to be read in on another computer.  */
  int print_symbols = 0;

  /* protocol */
  if(*dl < 1) return -1;
  protocol_nr = (*d)[0];
  (*d)++;
  (*dl)--;
  protocol = getprotobynumber((int)protocol_nr);
  if(protocol && (protocol->p_name != NULL)) {
    w += sldns_str_print(s, sl, "%s", protocol->p_name);
    proto_name = protocol->p_name;
  } else if(protocol_nr == 6) {
    w += sldns_str_print(s, sl, "tcp");
  } else if(protocol_nr == 17) {
    w += sldns_str_print(s, sl, "udp");
  } else {
    w += sldns_str_print(s, sl, "%u", (unsigned)protocol_nr);
  }

  for(i=0; i<*dl; i++) {
    if((*d)[i] == 0)
      continue;
    for(bit=0; bit<8; bit++) {
      if(!(((*d)[i])&(0x80>>bit)))
        continue;
      port = (int)i*8 + bit;

      if(!print_symbols)
        service = NULL;
      else
        service = getservbyport(
          (int)htons((uint16_t)port), proto_name);
      if(service && service->s_name)
        w += sldns_str_print(s, sl, " %s",
          service->s_name);
      else  w += sldns_str_print(s, sl, " %u",
          (unsigned)port);
    }
  }

#ifdef HAVE_ENDSERVENT
  endservent();
#endif
#ifdef HAVE_ENDPROTOENT
        endprotoent();
#endif
  (*d) += *dl;
  (*dl) = 0;
  return w;
}

int sldns_wire2str_nsap_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  return print_remainder_hex("0x", d, dl, s, sl);
}

int sldns_wire2str_atma_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  return print_remainder_hex("", d, dl, s, sl);
}

/* internal scan routine that can modify arguments on failure */
static int sldns_wire2str_ipseckey_scan_internal(uint8_t** d, size_t* dl,
  char** s, size_t* sl, uint8_t* pkt, size_t pktlen, int* comprloop)
{
  /* http://www.ietf.org/internet-drafts/draft-ietf-ipseckey-rr-12.txt*/
  uint8_t precedence, gateway_type, algorithm;
  int w = 0;

  if(*dl < 3) return -1;
  precedence = (*d)[0];
  gateway_type = (*d)[1];
  algorithm = (*d)[2];
  if(gateway_type > 3)
    return -1; /* unknown */
  (*d)+=3;
  (*dl)-=3;
  w += sldns_str_print(s, sl, "%d %d %d ",
    (int)precedence, (int)gateway_type, (int)algorithm);

  switch(gateway_type) {
  case 0: /* no gateway */
    w += sldns_str_print(s, sl, ".");
    break;
  case 1: /* ip4 */
    w += sldns_wire2str_a_scan(d, dl, s, sl);
    break;
  case 2: /* ip6 */
    w += sldns_wire2str_aaaa_scan(d, dl, s, sl);
    break;
  case 3: /* dname */
    w += sldns_wire2str_dname_scan(d, dl, s, sl, pkt, pktlen, comprloop);
    break;
  default: /* unknown */
    return -1;
  }

  if(*dl < 1)
    return -1;
  w += sldns_str_print(s, sl, " ");
  w += sldns_wire2str_b64_scan_num(d, dl, s, sl, *dl);
  return w;
}

int sldns_wire2str_ipseckey_scan(uint8_t** d, size_t* dl, char** s, size_t* sl,
  uint8_t* pkt, size_t pktlen, int* comprloop)
{
  uint8_t* od = *d;
  char* os = *s;
  size_t odl = *dl, osl = *sl;
  int w=sldns_wire2str_ipseckey_scan_internal(d, dl, s, sl, pkt, pktlen, comprloop);
  if(w == -1) {
    *d = od;
    *s = os;
    *dl = odl;
    *sl = osl;
    return -1;
  }
  return w;
}

int sldns_wire2str_hip_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  uint8_t algo, hitlen;
  uint16_t pklen;

  /* read lengths */
  if(*dl < 4)
    return -1;
  hitlen = (*d)[0];
  algo = (*d)[1];
  pklen = sldns_read_uint16((*d)+2);
  if(*dl < (size_t)4 + (size_t)hitlen + (size_t)pklen)
    return -1;

  /* write: algo hit pubkey */
  w = sldns_str_print(s, sl, "%u ", (unsigned)algo);
  w += print_hex_buf(s, sl, (*d)+4, hitlen);
  w += sldns_str_print(s, sl, " ");
  (*d)+=4+hitlen;
  (*dl)-= (4+hitlen);
  w += sldns_wire2str_b64_scan_num(d, dl, s, sl, pklen);
  return w;
}

int sldns_wire2str_int16_data_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  uint16_t n;
  if(*dl < 2)
    return -1;
  n = sldns_read_uint16(*d);
  if(*dl < 2+(size_t)n)
    return -1;
  (*d)+=2;
  (*dl)-=2;
  if(n == 0) {
    return sldns_str_print(s, sl, "0");
  }
  w = sldns_str_print(s, sl, "%u ", (unsigned)n);
  w += sldns_wire2str_b64_scan_num(d, dl, s, sl, n);
  return w;
}

int sldns_wire2str_nsec3_next_owner_scan(uint8_t** d, size_t* dl, char** s,
  size_t* sl)
{
  return sldns_wire2str_b32_ext_scan(d, dl, s, sl);
}

int sldns_wire2str_ilnp64_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  if(*dl < 8)
    return -1;
  w = sldns_str_print(s, sl, "%.4x:%.4x:%.4x:%.4x",
    sldns_read_uint16(*d), sldns_read_uint16((*d)+2),
    sldns_read_uint16((*d)+4), sldns_read_uint16((*d)+6));
  (*d)+=8;
  (*dl)-=8;
  return w;
}

int sldns_wire2str_eui48_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  if(*dl < 6)
    return -1;
  w = sldns_str_print(s, sl, "%.2x-%.2x-%.2x-%.2x-%.2x-%.2x",
    (*d)[0], (*d)[1], (*d)[2], (*d)[3], (*d)[4], (*d)[5]);
  (*d)+=6;
  (*dl)-=6;
  return w;
}

int sldns_wire2str_eui64_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  int w;
  if(*dl < 8)
    return -1;
  w = sldns_str_print(s, sl, "%.2x-%.2x-%.2x-%.2x-%.2x-%.2x-%.2x-%.2x",
    (*d)[0], (*d)[1], (*d)[2], (*d)[3], (*d)[4], (*d)[5],
    (*d)[6], (*d)[7]);
  (*d)+=8;
  (*dl)-=8;
  return w;
}

int sldns_wire2str_tag_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  size_t i, n;
  int w = 0;
  if(*dl < 1)
    return -1;
  n = (size_t)((*d)[0]);
  if(*dl < 1+n)
    return -1;
  for(i=0; i<n; i++)
    if(!isalnum((unsigned char)(*d)[i+1]))
      return -1;
  for(i=0; i<n; i++)
    w += sldns_str_print(s, sl, "%c", (char)(*d)[i+1]);
  (*d)+=n+1;
  (*dl)-=(n+1);
  return w;
}

int sldns_wire2str_long_str_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  size_t i;
  int w = 0;
  w += sldns_str_print(s, sl, "\"");
  for(i=0; i<*dl; i++)
    w += str_char_print(s, sl, (*d)[i]);
  w += sldns_str_print(s, sl, "\"");
  (*d)+=*dl;
  (*dl)=0;
  return w;
}

int sldns_wire2str_tsigerror_scan(uint8_t** d, size_t* dl, char** s, size_t* sl)
{
  sldns_lookup_table *lt;
  int data, w;
  if(*dl < 2) return -1;
  data = (int)sldns_read_uint16(*d);
  lt = sldns_lookup_by_id(sldns_tsig_errors, data);
  if(lt && lt->name)
    w = sldns_str_print(s, sl, "%s", lt->name);
  else  w = sldns_str_print(s, sl, "%d", data);
  (*dl)-=2;
  (*d)+=2;
  return w;
}

int sldns_wire2str_edns_llq_print(char** s, size_t* sl, uint8_t* data,
  size_t len)
{
  /* LLQ constants */
  const char* llq_errors[] = {"NO-ERROR", "SERV-FULL", "STATIC",
    "FORMAT-ERR", "NO-SUCH-LLQ", "BAD-VERS", "UNKNOWN_ERR"};
  const unsigned int llq_errors_num = 7;
  const char* llq_opcodes[] = {"LLQ-SETUP", "LLQ-REFRESH", "LLQ-EVENT"};
  const unsigned int llq_opcodes_num = 3;
  uint16_t version, llq_opcode, error_code;
  uint64_t llq_id;
  uint32_t lease_life; /* Requested or granted life of LLQ, in seconds */
  int w = 0;

  /* read the record */
  if(len != 18) {
    w += sldns_str_print(s, sl, "malformed LLQ ");
    w += print_hex_buf(s, sl, data, len);
    return w;
  }
  version = sldns_read_uint16(data);
  llq_opcode = sldns_read_uint16(data+2);
  error_code = sldns_read_uint16(data+4);
  memmove(&llq_id, data+6, sizeof(llq_id));
  lease_life = sldns_read_uint32(data+14);

  /* print it */
  w += sldns_str_print(s, sl, "v%d ", (int)version);
  if(llq_opcode < llq_opcodes_num)
    w += sldns_str_print(s, sl, "%s", llq_opcodes[llq_opcode]);
  else  w += sldns_str_print(s, sl, "opcode %d", (int)llq_opcode);
  if(error_code < llq_errors_num)
    w += sldns_str_print(s, sl, " %s", llq_errors[error_code]);
  else  w += sldns_str_print(s, sl, " error %d", (int)error_code);
#ifndef USE_WINSOCK
  w += sldns_str_print(s, sl, " id %llx lease-life %lu",
    (unsigned long long)llq_id, (unsigned long)lease_life);
#else
  w += sldns_str_print(s, sl, " id %I64x lease-life %lu",
    (unsigned long long)llq_id, (unsigned long)lease_life);
#endif
  return w;
}

int sldns_wire2str_edns_ul_print(char** s, size_t* sl, uint8_t* data,
  size_t len)
{
  uint32_t lease;
  int w = 0;
  if(len != 4) {
    w += sldns_str_print(s, sl, "malformed UL ");
    w += print_hex_buf(s, sl, data, len);
    return w;
  }
  lease = sldns_read_uint32(data);
  w += sldns_str_print(s, sl, "lease %lu", (unsigned long)lease);
  return w;
}

int sldns_wire2str_edns_nsid_print(char** s, size_t* sl, uint8_t* data,
  size_t len)
{
  int w = 0;
  size_t i, printed=0;
  w += print_hex_buf(s, sl, data, len);
  for(i=0; i<len; i++) {
    if(isprint((unsigned char)data[i]) || data[i] == '\t') {
      if(!printed) {
        w += sldns_str_print(s, sl, " (");
        printed = 1;
      }
      w += sldns_str_print(s, sl, "%c", (char)data[i]);
    }
  }
  if(printed)
    w += sldns_str_print(s, sl, ")");
  return w;
}

int sldns_wire2str_edns_dau_print(char** s, size_t* sl, uint8_t* data,
  size_t len)
{
  sldns_lookup_table *lt;
  size_t i;
  int w = 0;
  for(i=0; i<len; i++) {
    lt = sldns_lookup_by_id(sldns_algorithms, (int)data[i]);
    if(lt && lt->name)
      w += sldns_str_print(s, sl, " %s", lt->name);
    else  w += sldns_str_print(s, sl, " %d", (int)data[i]);
  }
  return w;
}

int sldns_wire2str_edns_dhu_print(char** s, size_t* sl, uint8_t* data,
  size_t len)
{
  sldns_lookup_table *lt;
  size_t i;
  int w = 0;
  for(i=0; i<len; i++) {
    lt = sldns_lookup_by_id(sldns_hashes, (int)data[i]);
    if(lt && lt->name)
      w += sldns_str_print(s, sl, " %s", lt->name);
    else  w += sldns_str_print(s, sl, " %d", (int)data[i]);
  }
  return w;
}

int sldns_wire2str_edns_n3u_print(char** s, size_t* sl, uint8_t* data,
  size_t len)
{
  size_t i;
  int w = 0;
  for(i=0; i<len; i++) {
    if(data[i] == 1)
      w += sldns_str_print(s, sl, " SHA1");
    else  w += sldns_str_print(s, sl, " %d", (int)data[i]);
  }
  return w;
}

int sldns_wire2str_edns_subnet_print(char** s, size_t* sl, uint8_t* data,
  size_t len)
{
  int w = 0;
  uint16_t family;
  uint8_t source, scope;
  if(len < 4) {
    w += sldns_str_print(s, sl, "malformed subnet ");
    w += print_hex_buf(s, sl, data, len);
    return w;
  }
  family = sldns_read_uint16(data);
  source = data[2];
  scope = data[3];
  if(family == 1) {
    /* IP4 */
    char buf[64];
    uint8_t ip4[4];
    memset(ip4, 0, sizeof(ip4));
    if(len-4 > 4) {
      w += sldns_str_print(s, sl, "trailingdata:");
      w += print_hex_buf(s, sl, data+4+4, len-4-4);
      w += sldns_str_print(s, sl, " ");
      len = 4+4;
    }
    memmove(ip4, data+4, len-4);
    if(!inet_ntop(AF_INET, ip4, buf, (socklen_t)sizeof(buf))) {
      w += sldns_str_print(s, sl, "ip4ntoperror ");
      w += print_hex_buf(s, sl, data+4+4, len-4-4);
    } else {
      w += sldns_str_print(s, sl, "%s", buf);
    }
  } else if(family == 2) {
    /* IP6 */
    char buf[64];
    uint8_t ip6[16];
    memset(ip6, 0, sizeof(ip6));
    if(len-4 > 16) {
      w += sldns_str_print(s, sl, "trailingdata:");
      w += print_hex_buf(s, sl, data+4+16, len-4-16);
      w += sldns_str_print(s, sl, " ");
      len = 4+16;
    }
    memmove(ip6, data+4, len-4);
#ifdef AF_INET6
    if(!inet_ntop(AF_INET6, ip6, buf, (socklen_t)sizeof(buf))) {
      w += sldns_str_print(s, sl, "ip6ntoperror ");
      w += print_hex_buf(s, sl, data+4+4, len-4-4);
    } else {
      w += sldns_str_print(s, sl, "%s", buf);
    }
#else
    w += print_hex_buf(s, sl, data+4+4, len-4-4);
#endif
  } else {
    /* unknown */
    w += sldns_str_print(s, sl, "family %d ",
      (int)family);
    w += print_hex_buf(s, sl, data, len);
  }
  w += sldns_str_print(s, sl, "/%d scope /%d", (int)source, (int)scope);
  return w;
}

static int sldns_wire2str_edns_keepalive_print(char** s, size_t* sl,
  uint8_t* data, size_t len)
{
  int w = 0;
  uint16_t timeout;
  if(!(len == 0 || len == 2)) {
    w += sldns_str_print(s, sl, "malformed keepalive ");
    w += print_hex_buf(s, sl, data, len);
    return w;
  }
  if(len == 0 ) {
    w += sldns_str_print(s, sl, "no timeout value (only valid for client option) ");
  } else {
    timeout = sldns_read_uint16(data);
    w += sldns_str_print(s, sl, "timeout value in units of 100ms %u", (int)timeout);
  }
  return w;
}

int sldns_wire2str_edns_option_print(char** s, size_t* sl,
  uint16_t option_code, uint8_t* optdata, size_t optlen)
{
  int w = 0;
  w += sldns_wire2str_edns_option_code_print(s, sl, option_code);
  w += sldns_str_print(s, sl, ": ");
  switch(option_code) {
  case LDNS_EDNS_LLQ:
    w += sldns_wire2str_edns_llq_print(s, sl, optdata, optlen);
    break;
  case LDNS_EDNS_UL:
    w += sldns_wire2str_edns_ul_print(s, sl, optdata, optlen);
    break;
  case LDNS_EDNS_NSID:
    w += sldns_wire2str_edns_nsid_print(s, sl, optdata, optlen);
    break;
  case LDNS_EDNS_DAU:
    w += sldns_wire2str_edns_dau_print(s, sl, optdata, optlen);
    break;
  case LDNS_EDNS_DHU:
    w += sldns_wire2str_edns_dhu_print(s, sl, optdata, optlen);
    break;
  case LDNS_EDNS_N3U:
    w += sldns_wire2str_edns_n3u_print(s, sl, optdata, optlen);
    break;
  case LDNS_EDNS_CLIENT_SUBNET:
    w += sldns_wire2str_edns_subnet_print(s, sl, optdata, optlen);
    break;
   case LDNS_EDNS_KEEPALIVE:
    w += sldns_wire2str_edns_keepalive_print(s, sl, optdata, optlen);
    break;
  case LDNS_EDNS_PADDING:
    w += print_hex_buf(s, sl, optdata, optlen);
    break;
  default:
    /* unknown option code */
    w += print_hex_buf(s, sl, optdata, optlen);
    break;
  }
  return w;
}

/** print the edns options to string */
static int
print_edns_opts(char** s, size_t* sl, uint8_t* rdata, size_t rdatalen)
{
  uint16_t option_code, option_len;
  int w = 0;
  while(rdatalen > 0) {
    /* option name */
    if(rdatalen < 4) {
      w += sldns_str_print(s, sl, " ; malformed: ");
      w += print_hex_buf(s, sl, rdata, rdatalen);
      return w;
    }
    option_code = sldns_read_uint16(rdata);
    option_len = sldns_read_uint16(rdata+2);
    rdata += 4;
    rdatalen -= 4;

    /* option value */
    if(rdatalen < (size_t)option_len) {
      w += sldns_str_print(s, sl, " ; malformed ");
      w += sldns_wire2str_edns_option_code_print(s, sl,
        option_code);
      w += sldns_str_print(s, sl, ": ");
      w += print_hex_buf(s, sl, rdata, rdatalen);
      return w;
    }
    w += sldns_str_print(s, sl, " ; ");
    w += sldns_wire2str_edns_option_print(s, sl, option_code,
      rdata, option_len);
    rdata += option_len;
    rdatalen -= option_len;
  }
  return w;
}

int sldns_wire2str_edns_scan(uint8_t** data, size_t* data_len, char** str,
        size_t* str_len, uint8_t* pkt, size_t pktlen)
{
  int w = 0;
  uint8_t ext_rcode, edns_version;
  uint16_t udpsize, edns_bits, rdatalen;
  w += sldns_str_print(str, str_len, "; EDNS:");

  /* some input checks, domain name */
  if(*data_len < 1+10)
    return w + print_remainder_hex("Error malformed 0x",
      data, data_len, str, str_len);
  if(*data[0] != 0) {
    return w + print_remainder_hex("Error nonrootdname 0x",
      data, data_len, str, str_len);
  }
  (*data)++;
  (*data_len)--;

  /* check type and read fixed contents */
  if(sldns_read_uint16((*data)) != LDNS_RR_TYPE_OPT) {
    return w + print_remainder_hex("Error nottypeOPT 0x",
      data, data_len, str, str_len);
  }
  udpsize = sldns_read_uint16((*data)+2);
  ext_rcode = (*data)[4];
  edns_version = (*data)[5];
  edns_bits = sldns_read_uint16((*data)+6);
  rdatalen = sldns_read_uint16((*data)+8);
  (*data)+=10;
  (*data_len)-=10;

  w += sldns_str_print(str, str_len, " version: %u;",
    (unsigned)edns_version);
  w += sldns_str_print(str, str_len, " flags:");
  if((edns_bits & LDNS_EDNS_MASK_DO_BIT))
    w += sldns_str_print(str, str_len, " do");
  /* the extended rcode is the value set, shifted four bits,
   * and or'd with the original rcode */
  if(ext_rcode) {
    int rc = ((int)ext_rcode)<<4;
    if(pkt && pktlen >= LDNS_HEADER_SIZE)
      rc |= LDNS_RCODE_WIRE(pkt);
    w += sldns_str_print(str, str_len, " ; ext-rcode: %d", rc);
  }
  w += sldns_str_print(str, str_len, " ; udp: %u", (unsigned)udpsize);

  if(rdatalen) {
    if((size_t)*data_len < rdatalen) {
      w += sldns_str_print(str, str_len,
        " ; Error EDNS rdata too short; ");
      rdatalen = (uint16_t)*data_len;
    }
    w += print_edns_opts(str, str_len, *data, rdatalen);
    (*data) += rdatalen;
    (*data_len) -= rdatalen;
  }
  w += sldns_str_print(str, str_len, "\n");
  return w;
}

Coverage Report

Created: 2023-03-26 06:08