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Added support for DNS64 translation of DNS queries for IPv6 addresses to IPv4 addresses, and the translation of responses from IPv4 to IPv6

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This commit is contained in:
Adam Dunkels 2015-03-24 11:56:14 +01:00
parent 251813a6dd
commit 269188846c
3 changed files with 329 additions and 3 deletions
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259
core/net/ip64/ip64-dns64.c Normal file
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@ -0,0 +1,259 @@
/*
* Copyright (c) 2014, Thingsquare, http://www.thingsquare.com/.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the copyright holder 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.
*
*/
#include "ip64.h"
#include "ip64-addr.h"
#include "ip64-dns64.h"
#include <stdio.h>
#define DEBUG 0
#if DEBUG
#undef PRINTF
#define PRINTF(...) printf(__VA_ARGS__)
#else /* DEBUG */
#define PRINTF(...)
#endif /* DEBUG */
struct dns_hdr {
uint8_t id[2];
uint8_t flags1, flags2;
#define DNS_FLAG1_RESPONSE 0x80
#define DNS_FLAG1_OPCODE_STATUS 0x10
#define DNS_FLAG1_OPCODE_INVERSE 0x08
#define DNS_FLAG1_OPCODE_STANDARD 0x00
#define DNS_FLAG1_AUTHORATIVE 0x04
#define DNS_FLAG1_TRUNC 0x02
#define DNS_FLAG1_RD 0x01
#define DNS_FLAG2_RA 0x80
#define DNS_FLAG2_ERR_MASK 0x0f
#define DNS_FLAG2_ERR_NONE 0x00
#define DNS_FLAG2_ERR_NAME 0x03
uint8_t numquestions[2];
uint8_t numanswers[2];
uint8_t numauthrr[2];
uint8_t numextrarr[2];
};
#define DNS_QUESTION_TYPE0 0
#define DNS_QUESTION_TYPE1 1
#define DNS_QUESTION_CLASS0 2
#define DNS_QUESTION_CLASS1 3
#define DNS_QUESTION_SIZE 4
struct dns_answer {
/* DNS answer record starts with either a domain name or a pointer
* to a name already present somewhere in the packet. */
uint8_t type[2];
uint8_t class[2];
uint8_t ttl[4];
uint8_t len[2];
union {
uint8_t ip6[16];
uint8_t ip4[4];
} addr;
};
#define DNS_TYPE_A 1
#define DNS_TYPE_AAAA 28
#define DNS_CLASS_IN 1
#define DNS_CLASS_ANY 255
/*---------------------------------------------------------------------------*/
void
ip64_dns64_6to4(const uint8_t *ipv6data, int ipv6datalen,
uint8_t *ipv4data, int ipv4datalen)
{
int i, j;
int qlen;
uint8_t *qdata;
uint8_t *q;
struct dns_hdr *hdr;
hdr = (struct dns_hdr *)ipv4data;
PRINTF("ip64_dns64_6to4 id: %02x%02x\n", hdr->id[0], hdr->id[1]);
PRINTF("ip64_dns64_6to4 flags1: 0x%02x\n", hdr->flags1);
PRINTF("ip64_dns64_6to4 flags2: 0x%02x\n", hdr->flags2);
PRINTF("ip64_dns64_6to4 numquestions: 0x%02x\n", ((hdr->numquestions[0] << 8) + hdr->numquestions[1]));
PRINTF("ip64_dns64_6to4 numanswers: 0x%02x\n", ((hdr->numanswers[0] << 8) + hdr->numanswers[1]));
PRINTF("ip64_dns64_6to4 numauthrr: 0x%02x\n", ((hdr->numauthrr[0] << 8) + hdr->numauthrr[1]));
PRINTF("ip64_dns64_6to4 numextrarr: 0x%02x\n", ((hdr->numextrarr[0] << 8) + hdr->numextrarr[1]));
/* Find the DNS question header by scanning through the question
labels. */
qdata = ipv4data + sizeof(struct dns_hdr);
for(i = 0; i < ((hdr->numquestions[0] << 8) + hdr->numquestions[1]); i++) {
do {
qlen = *qdata;
qdata++;
for(j = 0; j < qlen; j++) {
qdata++;
if(qdata > ipv4data + ipv4datalen) {
PRINTF("ip64_dns64_6to4: packet ended while parsing\n");
return;
}
}
} while(qlen != 0);
q = qdata;
if(q[DNS_QUESTION_CLASS0] == 0 && q[DNS_QUESTION_CLASS1] == DNS_CLASS_IN &&
q[DNS_QUESTION_TYPE0] == 0 && q[DNS_QUESTION_TYPE1] == DNS_TYPE_AAAA) {
q[DNS_QUESTION_TYPE1] = DNS_TYPE_A;
}
qdata += DNS_QUESTION_SIZE;
}
}
/*---------------------------------------------------------------------------*/
int
ip64_dns64_4to6(const uint8_t *ipv4data, int ipv4datalen,
uint8_t *ipv6data, int ipv6datalen)
{
uint8_t n;
int i, j;
int qlen, len;
const uint8_t *qdata, *adata;
uint8_t *qcopy, *acopy, *lenptr;
uint8_t *q;
struct dns_hdr *hdr;
hdr = (struct dns_hdr *)ipv4data;
PRINTF("ip64_dns64_4to6 id: %02x%02x\n", hdr->id[0], hdr->id[1]);
PRINTF("ip64_dns64_4to6 flags1: 0x%02x\n", hdr->flags1);
PRINTF("ip64_dns64_4to6 flags2: 0x%02x\n", hdr->flags2);
PRINTF("ip64_dns64_4to6 numquestions: 0x%02x\n", ((hdr->numquestions[0] << 8) + hdr->numquestions[1]));
PRINTF("ip64_dns64_4to6 numanswers: 0x%02x\n", ((hdr->numanswers[0] << 8) + hdr->numanswers[1]));
PRINTF("ip64_dns64_4to6 numauthrr: 0x%02x\n", ((hdr->numauthrr[0] << 8) + hdr->numauthrr[1]));
PRINTF("ip64_dns64_4to6 numextrarr: 0x%02x\n", ((hdr->numextrarr[0] << 8) + hdr->numextrarr[1]));
/* Find the DNS answer header by scanning through the question
labels. */
qdata = ipv4data + sizeof(struct dns_hdr);
qcopy = ipv6data + sizeof(struct dns_hdr);
for(i = 0; i < ((hdr->numquestions[0] << 8) + hdr->numquestions[1]); i++) {
do {
qlen = *qdata;
qdata++;
qcopy++;
for(j = 0; j < qlen; j++) {
qdata++;
qcopy++;
if(qdata > ipv4data + ipv4datalen) {
PRINTF("ip64_dns64_4to6: packet ended while parsing\n");
return ipv6datalen;
}
}
} while(qlen != 0);
q = qcopy;
if(q[DNS_QUESTION_CLASS0] == 0 && q[DNS_QUESTION_CLASS1] == DNS_CLASS_IN &&
q[DNS_QUESTION_TYPE0] == 0 && q[DNS_QUESTION_TYPE1] == DNS_TYPE_AAAA) {
q[DNS_QUESTION_TYPE1] = DNS_TYPE_AAAA;
}
qdata += DNS_QUESTION_SIZE;
qcopy += DNS_QUESTION_SIZE;
}
adata = qdata;
acopy = qcopy;
/* Go through the answers section and update the answers. */
for(i = 0; i < ((hdr->numanswers[0] << 8) + hdr->numanswers[1]); i++) {
n = *adata;
if(n & 0xc0) {
/* Short-hand name format: 2 bytes */
*acopy++ = *adata++;
*acopy++ = *adata++;
} else {
/* Name spelled out */
do {
n = *adata;
adata++;
acopy++;
for(j = 0; j < n; j++) {
*acopy++ = *adata++;
}
} while(n != 0);
}
if(adata[0] == 0 && adata[1] == DNS_TYPE_A) {
/* Update the type field from A to AAAA */
*acopy = *adata;
acopy++;
adata++;
*acopy = DNS_TYPE_AAAA;
acopy++;
adata++;
/* Get the length of the address record. Should be 4. */
lenptr = &acopy[6];
len = (adata[6] << 8) + adata[7];
/* Copy the class, the TTL, and the data length */
memcpy(acopy, adata, 2 + 4 + 2);
acopy += 8;
adata += 8;
if(len == 4) {
uip_ip4addr_t addr;
uip_ipaddr(&addr, adata[0], adata[1], adata[2], adata[3]);
ip64_addr_4to6(&addr, (uip_ip6addr_t *)acopy);
adata += len;
acopy += 16;
lenptr[0] = 0;
lenptr[1] = 16;
ipv6datalen += 12;
} else {
memcpy(acopy, adata, len);
acopy += len;
adata += len;
}
} else {
len = (adata[8] << 8) + adata[9];
/* Copy the type, class, the TTL, and the data length */
memcpy(acopy, adata, 2 + 2 + 4 + 2);
acopy += 10;
adata += 10;
/* Copy the data */
memcpy(acopy, adata, len);
acopy += len;
adata += len;
}
}
return ipv6datalen;
}
/*---------------------------------------------------------------------------*/

40
core/net/ip64/ip64-dns64.h Normal file
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@ -0,0 +1,40 @@
/*
* Copyright (c) 2014, Thingsquare, http://www.thingsquare.com/.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the copyright holder 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.
*
*/
#ifndef IP64_DNS64_H_
#define IP64_DNS64_H_
void ip64_dns64_6to4(const uint8_t *ipv6data, int ipv6datalen,
uint8_t *ipv4data, int ipv4datalen);
int ip64_dns64_4to6(const uint8_t *ipv4data, int ipv4datalen,
uint8_t *ipv6data, int ipv6datalen);
#endif /* IP64_DNS64_H_ */

33
core/net/ip64/ip64.c
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@ -59,7 +59,8 @@
#include "ip64-special-ports.h"
#include "ip64-eth-interface.h"
#include "ip64-slip-interface.h"
#include "ip64-dns64.h"
#include "net/ipv6/uip-ds6.h"
#include "ip64-ipv4-dhcp.h"
#include "contiki-net.h"
@ -173,6 +174,8 @@ static uip_ip4addr_t ipv4_broadcast_addr;
#define TCP_SYN 0x02
#define TCP_RST 0x04
#define DNS_PORT 53
/*---------------------------------------------------------------------------*/
void
ip64_init(void)
@ -367,7 +370,7 @@ ip64_6to4(const uint8_t *ipv6packet, const uint16_t ipv6packet_len,
struct icmpv6_hdr *icmpv6hdr;
uint16_t ipv6len, ipv4len;
struct ip64_addrmap_entry *m;
v6hdr = (struct ipv6_hdr *)ipv6packet;
v4hdr = (struct ipv4_hdr *)resultpacket;
@ -435,6 +438,15 @@ ip64_6to4(const uint8_t *ipv6packet, const uint16_t ipv6packet_len,
case IP_PROTO_UDP:
PRINTF("ip64_6to4: UDP header\n");
v4hdr->proto = IP_PROTO_UDP;
/* Check if this is a DNS request. If so, we should rewrite it
with the DNS64 module. */
if(udphdr->destport == UIP_HTONS(DNS_PORT)) {
ip64_dns64_6to4((uint8_t *)v6hdr + IPV6_HDRLEN + sizeof(struct udp_hdr),
ipv6len - IPV6_HDRLEN - sizeof(struct udp_hdr),
(uint8_t *)udphdr + sizeof(struct udp_hdr),
BUFSIZE - IPV4_HDRLEN - sizeof(struct udp_hdr));
}
/* Compute and check the UDP checksum - since we're going to
recompute it ourselves, we must ensure that it was correct in
the first place. */
@ -575,7 +587,7 @@ ip64_6to4(const uint8_t *ipv6packet, const uint16_t ipv6packet_len,
/* Treat DNS requests specially: since the are one-shot, we
mark them as recyclable. */
if(udphdr->destport == UIP_HTONS(53)) {
if(udphdr->destport == UIP_HTONS(DNS_PORT)) {
ip64_addrmap_set_recycleble(m);
}
}
@ -707,6 +719,21 @@ ip64_4to6(const uint8_t *ipv4packet, const uint16_t ipv4packet_len,
switch(v4hdr->proto) {
case IP_PROTO_UDP:
v6hdr->nxthdr = IP_PROTO_UDP;
/* Check if this is a DNS request. If so, we should rewrite it
with the DNS64 module. */
if(udphdr->srcport == UIP_HTONS(DNS_PORT)) {
int len;
len = ip64_dns64_4to6((uint8_t *)v4hdr + IPV4_HDRLEN + sizeof(struct udp_hdr),
ipv4len - IPV4_HDRLEN - sizeof(struct udp_hdr),
(uint8_t *)v6hdr + IPV6_HDRLEN + sizeof(struct udp_hdr),
ipv6_packet_len - sizeof(struct udp_hdr));
ipv6_packet_len = len + sizeof(struct udp_hdr);
v6hdr->len[0] = ipv6_packet_len >> 8;
v6hdr->len[1] = ipv6_packet_len & 0xff;
ipv6len = ipv6_packet_len + IPV6_HDRLEN;
}
break;
case IP_PROTO_TCP: