Handle IPv6 packets and prepare for IPv6 DNS redirection

This commit is contained in:
ValdikSS 2018-02-16 17:35:24 +03:00
parent 8e7f4ff505
commit 3d36127f5b
3 changed files with 140 additions and 72 deletions

View File

@ -17,8 +17,8 @@
#include "dnsredir.h"
#include "uthash.h"
// IPv6 incompatible!
#define UDP_CONNRECORD_KEY_LEN 6
/* key ('4' for IPv4 or '6' for IPv6 + srcip[16] + srcport[2]) */
#define UDP_CONNRECORD_KEY_LEN 19
#define DNS_CLEANUP_INTERVAL_SEC 30
@ -32,10 +32,10 @@
#define uthash_strlen(s) UDP_CONNRECORD_KEY_LEN
typedef struct udp_connrecord {
/* key (srcip[4] + srcport[2]) */
/* key ('4' for IPv4 or '6' for IPv6 + srcip[16] + srcport[2]) */
char key[UDP_CONNRECORD_KEY_LEN];
time_t time; /* time when this record was added */
uint32_t dstip;
uint32_t dstip[4];
uint16_t dstport;
UT_hash_handle hh; /* makes this structure hashable */
} udp_connrecord_t;
@ -59,26 +59,60 @@ void flush_dns_cache() {
FreeLibrary(dnsapi);
}
inline static void construct_key(const uint32_t srcip, const uint16_t srcport, char *key) {
inline static void fill_key_data(char *key, const uint8_t is_ipv6, const uint32_t srcip[4],
const uint16_t srcport)
{
if (is_ipv6) {
*(uint8_t*)(key) = '6';
ipv6_copy_addr((uint32_t*)(key + sizeof(uint8_t)), srcip);
}
else {
*(uint8_t*)(key) = '4';
ipv4_copy_addr((uint32_t*)(key + sizeof(uint8_t)), srcip);
}
*(uint16_t*)(key + sizeof(uint8_t) + sizeof(uint32_t) * 4) = srcport;
}
inline static void fill_data_from_key(uint8_t *is_ipv6, uint32_t srcip[4], uint16_t *srcport,
const char *key)
{
if (key[0] == '6') {
*is_ipv6 = 1;
ipv6_copy_addr(srcip, (uint32_t*)(key + sizeof(uint8_t)));
}
else {
*is_ipv6 = 0;
ipv4_copy_addr(srcip, (uint32_t*)(key + sizeof(uint8_t)));
}
*srcport = *(uint16_t*)(key + sizeof(uint8_t) + sizeof(uint32_t) * 4);
}
inline static void construct_key(const uint32_t srcip[4], const uint16_t srcport,
char *key, int is_ipv6)
{
debug("Construct key enter\n");
if (key) {
debug("Constructing key\n");
*(uint32_t*)(key) = srcip;
*(uint16_t*)(key + sizeof(srcip)) = srcport;
fill_key_data(key, is_ipv6, srcip, srcport);
}
debug("Construct key end\n");
}
inline static void deconstruct_key(const char *key, udp_connrecord_t *connrecord,
conntrack_info_t *conn_info) {
inline static void deconstruct_key(const char *key, const udp_connrecord_t *connrecord,
conntrack_info_t *conn_info)
{
debug("Deconstruct key enter\n");
if (key && conn_info) {
debug("Deconstructing key\n");
fill_data_from_key(&conn_info->is_ipv6, conn_info->srcip,
&conn_info->srcport, key);
if (conn_info->is_ipv6)
ipv6_copy_addr(conn_info->dstip, connrecord->dstip);
else
ipv4_copy_addr(conn_info->dstip, connrecord->dstip);
conn_info->srcip = *(uint32_t*)(key);
conn_info->srcport = *(uint16_t*)(key + sizeof(conn_info->srcip));
conn_info->dstip = connrecord->dstip;
conn_info->dstport = connrecord->dstport;
}
debug("Deconstruct key end\n");
@ -99,17 +133,26 @@ static int check_get_udp_conntrack_key(const char *key, udp_connrecord_t **connr
return FALSE;
}
static int add_udp_conntrack(const uint32_t srcip, const uint16_t srcport,
const uint32_t dstip, const uint16_t dstport) {
static int add_udp_conntrack(const uint32_t srcip[4], const uint16_t srcport,
const uint32_t dstip[4], const uint16_t dstport,
const int is_ipv6
)
{
if (!(srcip && srcport && dstip && dstport))
return FALSE;
udp_connrecord_t *tmp_connrecord = malloc(sizeof(udp_connrecord_t));
construct_key(srcip, srcport, tmp_connrecord->key);
construct_key(srcip, srcport, tmp_connrecord->key, is_ipv6);
if (!check_get_udp_conntrack_key(tmp_connrecord->key, NULL)) {
tmp_connrecord->time = time(NULL);
tmp_connrecord->dstip = dstip;
if (is_ipv6) {
ipv6_copy_addr(tmp_connrecord->dstip, dstip);
}
else {
ipv4_copy_addr(tmp_connrecord->dstip, dstip);
}
tmp_connrecord->dstport = dstport;
HASH_ADD_STR(conntrack, key, tmp_connrecord);
debug("Added UDP conntrack\n");
@ -120,7 +163,7 @@ static int add_udp_conntrack(const uint32_t srcip, const uint16_t srcport,
return FALSE;
}
void dns_cleanup() {
static void dns_cleanup() {
udp_connrecord_t *tmp_connrecord, *tmp_connrecord2 = NULL;
if (last_cleanup == 0) {
@ -154,10 +197,11 @@ int dns_is_dns_packet(const char *packet_data, const UINT packet_dataLen, const
return FALSE;
}
int dns_handle_outgoing(const uint32_t srcip, const uint16_t srcport,
const uint32_t dstip, const uint16_t dstport,
const char *packet_data, const UINT packet_dataLen) {
int dns_handle_outgoing(const uint32_t srcip[4], const uint16_t srcport,
const uint32_t dstip[4], const uint16_t dstport,
const char *packet_data, const UINT packet_dataLen,
const uint8_t is_ipv6)
{
if (packet_dataLen < 16)
return FALSE;
@ -166,16 +210,16 @@ int dns_handle_outgoing(const uint32_t srcip, const uint16_t srcport,
if (dns_is_dns_packet(packet_data, packet_dataLen, 1)) {
/* Looks like DNS request */
debug("trying to add srcport = %hu, dstport = %hu\n", ntohs(srcport), ntohs(dstport));
return add_udp_conntrack(srcip, srcport, dstip, dstport);
return add_udp_conntrack(srcip, srcport, dstip, dstport, is_ipv6);
}
debug("____dns_handle_outgoing FALSE: srcport = %hu, dstport = %hu\n", ntohs(srcport), ntohs(dstport));
return FALSE;
}
int dns_handle_incoming(const uint32_t srcip, const uint16_t srcport,
int dns_handle_incoming(const uint32_t srcip[4], const uint16_t srcport,
const char *packet_data, const UINT packet_dataLen,
conntrack_info_t *conn_info) {
conntrack_info_t *conn_info, const uint8_t is_ipv6)
{
char key[UDP_CONNRECORD_KEY_LEN];
udp_connrecord_t *tmp_connrecord = NULL;
@ -186,7 +230,7 @@ int dns_handle_incoming(const uint32_t srcip, const uint16_t srcport,
if (dns_is_dns_packet(packet_data, packet_dataLen, 0)) {
/* Looks like DNS response */
construct_key(srcip, srcport, key);
construct_key(srcip, srcport, key, is_ipv6);
if (check_get_udp_conntrack_key(key, &tmp_connrecord) && tmp_connrecord) {
/* Connection exists in conntrack, moving on */
deconstruct_key(key, tmp_connrecord, conn_info);

View File

@ -1,19 +1,36 @@
#include <stdint.h>
typedef struct conntrack_info {
uint32_t srcip;
uint8_t is_ipv6;
uint32_t srcip[4];
uint16_t srcport;
uint32_t dstip;
uint32_t dstip[4];
uint16_t dstport;
} conntrack_info_t;
int dns_handle_incoming(const uint32_t srcip, const uint16_t srcport,
const char *packet_data, const UINT packet_dataLen,
conntrack_info_t *conn_info);
inline static void ipv4_copy_addr(uint32_t dst[4], const uint32_t src[4]) {
dst[0] = src[0];
dst[1] = 0;
dst[2] = 0;
dst[3] = 0;
}
int dns_handle_outgoing(const uint32_t srcip, const uint16_t srcport,
const uint32_t dstip, const uint16_t dstport,
const char *packet_data, const UINT packet_dataLen);
inline static void ipv6_copy_addr(uint32_t dst[4], const uint32_t src[4]) {
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
dst[3] = src[3];
}
int dns_handle_incoming(const uint32_t srcip[4], const uint16_t srcport,
const char *packet_data, const UINT packet_dataLen,
conntrack_info_t *conn_info, const uint8_t is_ipv6);
int dns_handle_outgoing(const uint32_t srcip[4], const uint16_t srcport,
const uint32_t dstip[4], const uint16_t dstport,
const char *packet_data, const UINT packet_dataLen,
const uint8_t is_ipv6
);
void flush_dns_cache();
int dns_is_dns_packet(const char *packet_data, const UINT packet_dataLen, const int outgoing);

View File

@ -89,12 +89,12 @@ static const char *http_methods[] = {
};
static struct option long_options[] = {
{"port", required_argument, 0, 'z' },
{"dns-addr", required_argument, 0, 'd' },
{"dns-port", required_argument, 0, 'g' },
{"dns-verb", no_argument, 0, 'v' },
{"blacklist", required_argument, 0, 'b' },
{0, 0, 0, 0 }
{"port", required_argument, 0, 'z' },
{"dns-addr", required_argument, 0, 'd' },
{"dns-port", required_argument, 0, 'g' },
{"dns-verb", no_argument, 0, 'v' },
{"blacklist", required_argument, 0, 'b' },
{0, 0, 0, 0 }
};
static char *filter_string = NULL;
@ -295,8 +295,10 @@ int main(int argc, char *argv[]) {
do_dns_verb = 0, do_blacklist = 0;
unsigned int http_fragment_size = 2;
unsigned int https_fragment_size = 2;
uint32_t dns_addr = 0;
uint16_t dns_port = htons(53);
uint32_t dnsv4_addr = 0;
uint32_t dnsv6_addr[4] = {0};
uint16_t dnsv4_port = htons(53);
uint16_t dnsv6_port = htons(53);
char *host_addr, *useragent_addr, *method_addr;
int host_len, useragent_len;
int http_req_fragmented;
@ -410,8 +412,8 @@ int main(int argc, char *argv[]) {
case 'd':
if (!do_dns_redirect) {
do_dns_redirect = 1;
dns_addr = inet_addr(optarg);
if (!dns_addr) {
dnsv4_addr = inet_addr(optarg);
if (!dnsv4_addr) {
printf("DNS address parameter error!\n");
exit(EXIT_FAILURE);
}
@ -426,15 +428,15 @@ int main(int argc, char *argv[]) {
"--dns-port\n");
exit(EXIT_FAILURE);
}
dns_port = atoi(optarg);
dnsv4_port = atoi(optarg);
if (atoi(optarg) <= 0 || atoi(optarg) > 65535) {
printf("DNS port parameter error!\n");
exit(EXIT_FAILURE);
}
if (dns_port != 53) {
add_filter_str(IPPROTO_UDP, dns_port);
if (dnsv4_port != 53) {
add_filter_str(IPPROTO_UDP, dnsv4_port);
}
dns_port = htons(dns_port);
dnsv4_port = htons(dnsv4_port);
break;
case 'v':
do_dns_verb = 1;
@ -447,7 +449,7 @@ int main(int argc, char *argv[]) {
}
break;
default:
printf("Usage: goodbyedpi.exe [OPTION...]\n"
puts("Usage: goodbyedpi.exe [OPTION...]\n"
" -p block passive DPI\n"
" -r replace Host with hoSt\n"
" -s remove space between host header and its value\n"
@ -458,17 +460,19 @@ int main(int argc, char *argv[]) {
" -n do not wait for first segment ACK when -k is enabled\n"
" -e [value] set HTTPS fragmentation to value\n"
" -w try to find and parse HTTP traffic on all processed ports (not only on port 80)\n"
" --port [value] additional TCP port to perform fragmentation on (and HTTP tricks with -w)\n"
" --dns-addr [value] redirect UDP DNS requests to the supplied IP address (experimental)\n"
" --dns-port [value] redirect UDP DNS requests to the supplied port (53 by default)\n"
" --dns-verb print verbose DNS redirection messages\n"
" --blacklist [txtfile] perform HTTP tricks only to host names and subdomains from\n"
" supplied text file. This option can be supplied multiple times.\n"
" --port [value] additional TCP port to perform fragmentation on (and HTTP tricks with -w)\n"
" --dns-addr [value] redirect UDPv4 DNS requests to the supplied IPv4 address (experimental)\n"
" --dns-port [value] redirect UDPv4 DNS requests to the supplied port (53 by default)\n"
" --dnsv6-addr [value] redirect UDPv6 DNS requests to the supplied IPv6 address (experimental)\n"
" --dnsv6-port [value] redirect UDPv6 DNS requests to the supplied port (53 by default)\n"
" --dns-verb print verbose DNS redirection messages\n"
" --blacklist [txtfile] perform HTTP tricks only to host names and subdomains from\n"
" supplied text file. This option can be supplied multiple times.\n"
"\n"
" -1 -p -r -s -f 2 -k 2 -n -e 2 (most compatible mode, default)\n"
" -2 -p -r -s -f 2 -k 2 -n -e 40 (better speed for HTTPS yet still compatible)\n"
" -3 -p -r -s -e 40 (better speed for HTTP and HTTPS)\n"
" -4 -p -r -s (best speed)\n");
" -4 -p -r -s (best speed)");
exit(EXIT_FAILURE);
}
}
@ -770,20 +774,20 @@ int main(int argc, char *argv[]) {
(packet_type == ipv4_udp_data || packet_type == ipv6_udp_data)) {
if (addr.Direction == WINDIVERT_DIRECTION_INBOUND) {
if ((packet_v4 && dns_handle_incoming(ppIpHdr->DstAddr, ppUdpHdr->DstPort,
if ((packet_v4 && dns_handle_incoming(&ppIpHdr->DstAddr, ppUdpHdr->DstPort,
packet_data, packet_dataLen,
&dns_conn_info))
&dns_conn_info, 0))
/*||
(packet_v6 && dns_handle_incoming(ppIpV6Hdr->DstAddr, ppUdpHdr->DstPort,
packet_data, packet_dataLen,
&dns_conn_info))*/)
&dns_conn_info, 1))*/)
{
/* Changing source IP and port to the values
* from DNS conntrack */
if (packet_v4)
ppIpHdr->SrcAddr = dns_conn_info.dstip;
/*else if (packet_v6)
ppIpV6Hdr->SrcAddr = dns_conn_info.dstip;*/
ppIpHdr->SrcAddr = dns_conn_info.dstip[0];
else if (packet_v6)
ipv6_copy_addr(ppIpV6Hdr->SrcAddr, dns_conn_info.dstip);
ppUdpHdr->DstPort = dns_conn_info.srcport;
ppUdpHdr->SrcPort = dns_conn_info.dstport;
should_recalc_checksum = 1;
@ -800,21 +804,24 @@ int main(int argc, char *argv[]) {
}
else if (addr.Direction == WINDIVERT_DIRECTION_OUTBOUND) {
if ((packet_v4 && dns_handle_outgoing(ppIpHdr->SrcAddr, ppUdpHdr->SrcPort,
ppIpHdr->DstAddr, ppUdpHdr->DstPort,
packet_data, packet_dataLen))
if ((packet_v4 && dns_handle_outgoing(&ppIpHdr->SrcAddr, ppUdpHdr->SrcPort,
&ppIpHdr->DstAddr, ppUdpHdr->DstPort,
packet_data, packet_dataLen, 0))
/*||
(packet_v6 && dns_handle_outgoing(ppIpV6Hdr->SrcAddr, ppUdpHdr->SrcPort,
ppIpV6Hdr->DstAddr, ppUdpHdr->DstPort,
packet_data, packet_dataLen))*/)
packet_data, packet_dataLen, 1))*/)
{
/* Changing destination IP and port to the values
* from configuration */
if (packet_v4)
ppIpHdr->DstAddr = dns_addr;
/*else if (packet_v6)
ppIpV6Hdr->DstAddr = dns_addr;*/
ppUdpHdr->DstPort = dns_port;
if (packet_v4) {
ppIpHdr->DstAddr = dnsv4_addr;
ppUdpHdr->DstPort = dnsv4_port;
}
else if (packet_v6) {
ipv6_copy_addr(ppIpV6Hdr->DstAddr, dnsv6_addr);
ppUdpHdr->DstPort = dnsv6_port;
}
should_recalc_checksum = 1;
}
else {