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attempting to add a dns packet parser

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hyung-hwan
2020-02-11 15:51:41 +00:00
parent c6e3b6204b
commit 42fe77bde5
2 changed files with 134 additions and 114 deletions
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246
mio/lib/dns.c
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@ -387,113 +387,6 @@ static mio_dns_msg_t* build_dns_msg (mio_svc_dnc_t* dnc, mio_dns_bdns_t* bdns, m
return msg;
}
static int parse_dns_pkt (mio_svc_dnc_t* dnc, mio_dns_pkt_t* pkt, mio_oow_t len)
{
mio_t* mio = dnc->mio;
mio_dns_bdns_t* bdns;
mio_uint16_t i, rrc;
mio_uint8_t* dn;
mio_uint8_t* pktend = (mio_uint8_t*)pkt + len;
MIO_ASSERT (mio, len >= MIO_SIZEOF(*pkt));
return 0;
/* TODO: */
bdns->id = mio_ntoh16(pkt->id);
bdns->qr = pkt->qr & 0x01;
bdns->opcode = pkt->opcode & 0x0F;
bdns->aa = pkt->aa & 0x01;
bdns->tc = pkt->tc & 0x01;
bdns->rd = pkt->rd & 0x01;
bdns->ra = pkt->ra & 0x01;
bdns->ad = pkt->ad & 0x01;
bdns->cd = pkt->cd & 0x01;
bdns->rcode = pkt->rcode & 0x0F;
/*
bdns->qdcount = mio_ntoh16(pkt->qdcount);
bdns->ancount = mio_ntoh16(pkt->ancount);
bdns->nscount = mio_ntoh16(pkt->nscount);
bdns->arcount = mio_ntoh16(pkt->arcount);
*/
dn = (mio_uint8_t*)(pkt + 1);
rrc = mio_ntoh16(pkt->qdcount);
for (i = 0; i < rrc; i++)
{
mio_oow_t totlen, seglen;
mio_dns_qrtr_t* qrtr;
if (dn >= pktend)
{
mio_seterrbfmt (mio, MIO_EINVAL, "invalid packet");
return -1;
}
totlen = 0;
while ((seglen = *dn++) > 0)
{
if (seglen > 64)
{
/* compressed. pointer to somewhere else */
/* TODO: */
}
totlen += seglen;
dn += seglen;
}
qrtr = (mio_dns_qrtr_t*)dn;
dn += MIO_SIZEOF(*qrtr);
}
rrc = mio_ntoh16(pkt->ancount);
for (i = 0; i < rrc; i++)
{
mio_oow_t totlen, seglen;
mio_dns_rrtr_t* rrtr;
if (dn >= pktend)
{
mio_seterrbfmt (mio, MIO_EINVAL, "invalid packet");
return -1;
}
totlen = 0;
while ((seglen = *dn++) > 0)
{
totlen += seglen;
dn += seglen;
}
rrtr = (mio_dns_rrtr_t*)dn;
dn += MIO_SIZEOF(*rrtr) + rrtr->dlen;
}
#if 0
for (i = 0; i < bdns->nscount; i++)
{
}
for (i = 0; i < bdns->arcount; i++)
{
#if 0
if (*dn == 0)
{
rrtr = (mio_dns_rrtr_t*)(dn + 1);
if (rrtr->qtype == MIO_CONST_HTON16(MIO_DNS_QTYPE_OPT)
{
/* edns */
}
}
#endif
}
#endif
return 0;
}
/* ----------------------------------------------------------------------- */
static int dnc_on_read (mio_dev_sck_t* dev, const void* data, mio_iolen_t dlen, const mio_sckaddr_t* srcaddr)
@ -528,8 +421,6 @@ static int dnc_on_read (mio_dev_sck_t* dev, const void* data, mio_iolen_t dlen,
if (dev == (mio_dev_sck_t*)reqmsg->dev && pkt->id == reqpkt->id) /* TODO: check the source address against the target address */
{
MIO_DEBUG1 (mio, "received dns response...id %d\n", id);
/* TODO: parse the response... perform actual work. pass the result back?? */
/*parse_dns_pkt (dnc, pkt, dlen);*/
if (MIO_LIKELY(reqmsg->ctx))
((mio_svc_dnc_on_reply_t)reqmsg->ctx) (dnc, reqmsg, MIO_ENOERR, data, dlen);
@ -709,10 +600,6 @@ int mio_svc_dnc_sendreq (mio_svc_dnc_t* dnc, mio_dns_bdns_t* bdns, mio_dns_bqr_t
return 0;
}
static void on_dnc_resolve_reply (mio_svc_dnc_t* dnc, mio_dns_msg_t* reqmsg, mio_errnum_t status, const void* data, mio_oow_t dlen)
{
}
int mio_svc_dnc_resolve (mio_svc_dnc_t* dnc, const mio_bch_t* qname, mio_dns_qtype_t qtype, mio_svc_dnc_on_reply_t on_reply)
{
static mio_dns_bdns_t qhdr =
@ -749,3 +636,136 @@ int mio_svc_dnc_resolve (mio_svc_dnc_t* dnc, const mio_bch_t* qname, mio_dns_qty
return mio_svc_dnc_sendreq(dnc, &qhdr, &qr, 1, &qedns, on_reply);
}
/* ----------------------------------------------------------------------- */
static mio_uint8_t* parse_question (mio_t* mio, mio_uint8_t* dn, mio_uint8_t* pktend)
{
mio_oow_t totlen, seglen;
mio_dns_qrtr_t* qrtr;
if (dn >= pktend)
{
mio_seterrbfmt (mio, MIO_EINVAL, "invalid packet");
return MIO_NULL;
}
totlen = 0;
while ((seglen = *dn++) > 0)
{
if (seglen > 64)
{
/* compressed. pointer to somewhere else */
/* TODO: */
}
totlen += seglen;
dn += seglen;
}
qrtr = (mio_dns_qrtr_t*)dn;
dn += MIO_SIZEOF(*qrtr);
return dn;
}
static mio_uint8_t* parse_answer (mio_t* mio, mio_uint8_t* dn, mio_uint8_t* pktend)
{
mio_oow_t totlen, seglen;
mio_dns_rrtr_t* rrtr;
if (dn >= pktend)
{
mio_seterrbfmt (mio, MIO_EINVAL, "invalid packet");
return MIO_NULL;
}
totlen = 0;
while ((seglen = *dn++) > 0)
{
totlen += seglen;
dn += seglen;
}
rrtr = (mio_dns_rrtr_t*)dn;
dn += MIO_SIZEOF(*rrtr) + rrtr->dlen;
return dn;
}
int mio_dns_parse_packet (mio_svc_dnc_t* dnc, mio_dns_pkt_t* pkt, mio_oow_t len, mio_dns_bdns_t* bdns)
{
mio_t* mio = dnc->mio;
mio_uint16_t i, rrc;
mio_uint8_t* dn;
mio_uint8_t* pktend = (mio_uint8_t*)pkt + len;
MIO_ASSERT (mio, len >= MIO_SIZEOF(*pkt));
bdns->id = mio_ntoh16(pkt->id);
bdns->qr = pkt->qr & 0x01;
bdns->opcode = pkt->opcode & 0x0F;
bdns->aa = pkt->aa & 0x01;
bdns->tc = pkt->tc & 0x01;
bdns->rd = pkt->rd & 0x01;
bdns->ra = pkt->ra & 0x01;
bdns->ad = pkt->ad & 0x01;
bdns->cd = pkt->cd & 0x01;
bdns->rcode = pkt->rcode & 0x0F;
/*
bdns->qdcount = mio_ntoh16(pkt->qdcount);
bdns->ancount = mio_ntoh16(pkt->ancount);
bdns->nscount = mio_ntoh16(pkt->nscount);
bdns->arcount = mio_ntoh16(pkt->arcount);
*/
dn = (mio_uint8_t*)(pkt + 1);
rrc = mio_ntoh16(pkt->qdcount);
for (i = 0; i < rrc; i++)
{
dn = parse_question(mio, dn, pktend);
if (!dn) return -1;
}
rrc = mio_ntoh16(pkt->ancount);
for (i = 0; i < rrc; i++)
{
dn = parse_answer(mio, dn, pktend);
if (!dn) return -1;
}
rrc = mio_ntoh16(pkt->nscount);
for (i = 0; i < rrc; i++)
{
dn = parse_answer(mio, dn, pktend);
if (!dn) return -1;
}
rrc = mio_ntoh16(pkt->arcount);
for (i = 0; i < rrc; i++)
{
dn = parse_answer(mio, dn, pktend);
if (!dn) return -1;
}
#if 0
for (i = 0; i < bdns->arcount; i++)
{
#if 0
if (*dn == 0)
{
rrtr = (mio_dns_rrtr_t*)(dn + 1);
if (rrtr->qtype == MIO_CONST_HTON16(MIO_DNS_QTYPE_OPT)
{
/* edns */
}
}
#endif
}
#endif
return 0;
}