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/* ISC license. */
#include <stdint.h>
#include <errno.h>
#include <skalibs/error.h>
#include <skalibs/uint16.h>
#include <skalibs/uint.h>
#include <skalibs/bytestr.h>
#include <skalibs/genwrite.h>
#include <s6-dns/s6dns-constants.h>
#include <s6-dns/s6dns-domain.h>
#include <s6-dns/s6dns-message.h>
#include <s6-dns/s6dns-analyze.h>
#define add(s) if ((*gp->put)(gp->target, (s), str_len(s)) < 0) return 0
#define addfmt(n) if ((*gp->put)(gp->target, fmt, uint_fmt(fmt, (n))) < 0) return 0
#define addfmt16(n) if ((*gp->put)(gp->target, fmt, uint16_fmt(fmt, (n))) < 0) return 0
int s6dns_analyze_packet (genwrite_t *gp, char const *packet, unsigned int packetlen, int rec)
{
s6dns_message_header_t h ;
s6dns_message_counts_t counts ;
unsigned int pos ;
unsigned int section ;
char fmt[UINT_FMT] ;
if (!s6dns_message_parse_init(&h, &counts, packet, packetlen, &pos))
return 0 ;
addfmt(packetlen) ;
add(" bytes, ") ;
addfmt16(counts.qd) ;
add("+") ;
addfmt16(counts.an) ;
add("+") ;
addfmt16(counts.ns) ;
add("+") ;
addfmt16(counts.nr) ;
add(" records") ;
if (h.qr) add(", response") ;
if (h.opcode)
{
add(", weird op (") ;
addfmt(h.opcode) ;
add(")") ;
}
if (h.aa) add(", authoritative") ;
if (h.tc) add(", truncated") ;
if (h.rd)
{
add(", ") ;
if (!rec) add("weird ") ;
add("rd") ;
}
if (h.ra)
{
add(", ") ;
if (!rec) add("weird ") ;
add("ra") ;
}
switch (h.rcode)
{
case 0 : add(", noerror") ; break ;
case 1 : add(", fmterror") ; break ;
case 2 : add(", servfail") ; break ;
case 3 : add(", nxdomain") ; break ;
case 4 : add(", notimpl") ; break ;
case 5 : add(", refused") ; break ;
default:
{
add(", weird rcode (") ;
addfmt(h.rcode) ;
add(")") ;
}
}
if (h.z)
{
add(", weird z (") ;
addfmt(h.z) ;
add(")") ;
}
add("\n") ;
for (;;)
{
s6dns_domain_t d ;
char buf[257] ;
unsigned int len ;
uint16_t qtype ;
uint16 qclass ;
section = s6dns_message_counts_next(&counts) ;
if (section != 1) break ;
add("query: ") ;
if (!s6dns_message_get_domain(&d, packet, packetlen, &pos)) return 0 ;
len = s6dns_domain_tostring(buf, 255, &d) ;
if (!len) return 0 ;
buf[len++] = '\n' ; buf[len++] = 0 ;
if (pos + 4 > packetlen) return (errno = EPROTO, 0) ;
uint16_unpack_big(packet + pos, &qtype) ; pos += 2 ;
uint16_unpack_big(packet + pos, &qclass) ; pos += 2 ;
if (qclass != S6DNS_C_IN)
{
add("weird class (") ;
addfmt16(qclass) ;
add(") - ") ;
}
addfmt16(qtype) ;
add(" ") ;
add(buf) ;
}
while (section)
{
static char const *intro[3] = { "answer: ", "authority: ", "additional: " } ;
s6dns_message_rr_t rr ;
if (!s6dns_message_parse_getrr(&rr, packet, packetlen, &pos)) return 0 ;
add(intro[section-2]) ;
if (rr.rclass != S6DNS_C_IN)
{
add("weird class (") ;
addfmt16(rr.rclass) ;
add("), not attempting to analyze record\n") ;
}
else if (!s6dns_analyze_record(gp, &rr, packet, packetlen, pos)) return 0 ;
section = s6dns_message_parse_next(&counts, &rr, packet, packetlen, &pos) ;
}
return 1 ;
}
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