IPv6 DNS redirection

No IPv6 support in DNS redirection code. IPv6 DNS request packets
would be dropped.

README.md

@@ -79,26 +79,8 @@ And for x86_64:
 
 # How to install as Windows Service
 
-One way is using an [srvstart](http://www.rozanski.org.uk/software) program.  
-Unpack it to `goodbyedpi` directory and create 3 files:
-
-*goodbyedpi.ini*
-```INI
-[GoodByeDPI]
-startup=goodbyedpi.exe
-shutdown_method=winmessage
-auto_restart=n
-```
-*srvinstall.bat*
-```Batchfile
-srvstart install GoodByeDPI -c %CD%\goodbyedpi.ini
-```
-*srvremove.bat*
-```Batchfile
-srvstart remove GoodByeDPI
-```
-Run these batch files as Administrator to install/remove service.  
-Open Windows Services panel to run service or make it start automaticaly.
+Use `service_install_russia_blacklist.cmd`, `service_install_russia_blacklist_dnsredir.cmd` and `service_remove.cmd` scripts.  
+Modify them according to your own needs.
 
 # Similar projects
 

dnsredir.c

@@ -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);

dnsredir.h

@@ -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);

goodbyedpi.c

@@ -9,29 +9,31 @@
 #include <unistd.h>
 #include <string.h>
 #include <getopt.h>
+#include <in6addr.h>
+#include <ws2tcpip.h>
 #include "windivert.h"
 #include "goodbyedpi.h"
+#include "service.h"
 #include "dnsredir.h"
 #include "blackwhitelist.h"
 
+WINSOCK_API_LINKAGE INT WSAAPI inet_pton(INT Family, LPCSTR pStringBuf, PVOID pAddr);
+
 #define die() do { printf("Something went wrong!\n" \
     "Make sure you're running this program with administrator privileges\n"); \
     sleep(10); exit(EXIT_FAILURE); } while (0)
 
 #define MAX_FILTERS 4
 #define MAX_PACKET_SIZE 9016
-#define IPV4_HDR_LEN 20
-#define TCP_HDR_LEN 20
-#define TCP_WINDOWSIZE_OFFSET 14
 
-#define DIVERT_NO_LOCALNETS_DST "(" \
+#define DIVERT_NO_LOCALNETSv4_DST "(" \
                    "(ip.DstAddr < 127.0.0.1 or ip.DstAddr > 127.255.255.255) and " \
                    "(ip.DstAddr < 10.0.0.0 or ip.DstAddr > 10.255.255.255) and " \
                    "(ip.DstAddr < 192.168.0.0 or ip.DstAddr > 192.168.255.255) and " \
                    "(ip.DstAddr < 172.16.0.0 or ip.DstAddr > 172.31.255.255) and " \
                    "(ip.DstAddr < 169.254.0.0 or ip.DstAddr > 169.254.255.255)" \
                    ")"
-#define DIVERT_NO_LOCALNETS_SRC "(" \
+#define DIVERT_NO_LOCALNETSv4_SRC "(" \
                    "(ip.SrcAddr < 127.0.0.1 or ip.SrcAddr > 127.255.255.255) and " \
                    "(ip.SrcAddr < 10.0.0.0 or ip.SrcAddr > 10.255.255.255) and " \
                    "(ip.SrcAddr < 192.168.0.0 or ip.SrcAddr > 192.168.255.255) and " \
@@ -39,15 +41,30 @@
                    "(ip.SrcAddr < 169.254.0.0 or ip.SrcAddr > 169.254.255.255)" \
                    ")"
 
+#define DIVERT_NO_LOCALNETSv6_DST "(" \
+                   "(ipv6.DstAddr > ::1) and " \
+                   "(ipv6.DstAddr < 2001::0 or ipv6.DstAddr > 2001:1::0) and " \
+                   "(ipv6.DstAddr < fc00::0 or ipv6.DstAddr > fe00::0) and " \
+                   "(ipv6.DstAddr < fe80::0 or ipv6.DstAddr > fec0::0) and " \
+                   "(ipv6.DstAddr < ff00::0 or ipv6.DstAddr > ffff::0)" \
+                   ")"
+#define DIVERT_NO_LOCALNETSv6_SRC "(" \
+                   "(ipv6.SrcAddr > ::1) and " \
+                   "(ipv6.SrcAddr < 2001::0 or ipv6.SrcAddr > 2001:1::0) and " \
+                   "(ipv6.SrcAddr < fc00::0 or ipv6.SrcAddr > fe00::0) and " \
+                   "(ipv6.SrcAddr < fe80::0 or ipv6.SrcAddr > fec0::0) and " \
+                   "(ipv6.SrcAddr < ff00::0 or ipv6.SrcAddr > ffff::0)" \
+                   ")"
+
 #define SET_HTTP_FRAGMENT_SIZE_OPTION(fragment_size) do { \
     if (!http_fragment_size) { \
-        http_fragment_size = fragment_size; \
-        if (http_fragment_size <= 0 || http_fragment_size > 65535) { \
-            printf(fragment_size_message); \
+        if (fragment_size <= 0 || fragment_size > 65535) { \
+            puts("Fragment size should be in range [0 - 65535]\n"); \
             exit(EXIT_FAILURE); \
         } \
+        http_fragment_size = fragment_size; \
     } \
-    else if (http_fragment_size != fragment_size) { \
+    else if (http_fragment_size != (unsigned int)fragment_size) { \
         printf( \
             "WARNING: HTTP fragment size is already set to %d, not changing.\n", \
             http_fragment_size \
@@ -55,6 +72,7 @@
     } \
 } while (0)
 
+static int running_from_service = 0;
 static HANDLE filters[MAX_FILTERS];
 static int filter_num = 0;
 static const char *http10_redirect_302 = "HTTP/1.0 302 ";
@@ -75,28 +93,35 @@ 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' },
+    {"dnsv6-addr",  required_argument, 0,  '!' },
+    {"dnsv6-port",  required_argument, 0,  '@' },
+    {"dns-verb",    no_argument,       0,  'v' },
+    {"blacklist",   required_argument, 0,  'b' },
+    {0,             0,                 0,   0  }
 };
 
 static char *filter_string = NULL;
-static char *filter_string_template = "(ip and tcp and "
-        "(inbound and (("
-         "((ip.Id == 0x0001 or ip.Id == 0x0000) and tcp.SrcPort == 80 and tcp.Ack) or "
-         "((tcp.SrcPort == 80 or tcp.SrcPort == 443) and tcp.Ack and tcp.Syn)"
-         ") and " DIVERT_NO_LOCALNETS_SRC ") or "
+static char *filter_string_template = "(tcp and "
+        "(inbound and ("
+         "("
+          "("
+           "(ip.Id >= 0x0 and ip.Id <= 0xF) and "
+           "tcp.SrcPort == 80 and tcp.Ack"
+          ") or "
+          "((tcp.SrcPort == 80 or tcp.SrcPort == 443) and tcp.Ack and tcp.Syn)"
+         ")"
+         " and (" DIVERT_NO_LOCALNETSv4_SRC " or " DIVERT_NO_LOCALNETSv6_SRC ")) or "
         "(outbound and "
          "(tcp.DstPort == 80 or tcp.DstPort == 443) and tcp.Ack and "
-         DIVERT_NO_LOCALNETS_DST ")"
+         "(" DIVERT_NO_LOCALNETSv4_DST " or " DIVERT_NO_LOCALNETSv6_DST "))"
         "))";
 
 static void add_filter_str(int proto, int port) {
-    const char *udp = " or (ip and udp and (udp.SrcPort == %d or udp.DstPort == %d))";
-    const char *tcp = " or (ip and tcp and (tcp.SrcPort == %d or tcp.DstPort == %d))";
+    const char *udp = " or (udp and (udp.SrcPort == %d or udp.DstPort == %d))";
+    const char *tcp = " or (tcp and (tcp.SrcPort == %d or tcp.DstPort == %d))";
 
     char *current_filter = filter_string;
     int new_filter_size = strlen(current_filter) +
@@ -134,7 +159,7 @@ static HANDLE init(char *filter, UINT64 flags) {
                   FORMAT_MESSAGE_IGNORE_INSERTS,
                   NULL, GetLastError(), MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
                   (LPTSTR)&errormessage, 0, NULL);
-    printf("%s", errormessage);
+    puts(errormessage);
     free(errormessage);
     return NULL;
 }
@@ -147,7 +172,7 @@ static int deinit(HANDLE handle) {
     return FALSE;
 }
 
-static void deinit_all() {
+void deinit_all() {
     for (int i = 0; i < filter_num; i++) {
         deinit(filters[i]);
     }
@@ -216,9 +241,9 @@ static int find_header_and_get_info(const char *pktdata, int pktlen,
     return FALSE;
 }
 
-static void change_window_size(const char *pkt, int size) {
+static inline void change_window_size(const PWINDIVERT_TCPHDR ppTcpHdr, int size) {
     if (size >= 1 && size <= 65535) {
-        *(uint16_t*)(pkt + IPV4_HDR_LEN + TCP_WINDOWSIZE_OFFSET) = htons(size);
+        ppTcpHdr->Window = htons(size);
     }
 }
 
@@ -246,10 +271,14 @@ static PVOID find_http_method_end(const char *pkt, int http_frag, int *is_fragme
 }
 
 int main(int argc, char *argv[]) {
-    static const char fragment_size_message[] =
-                "Fragment size should be in range [0 - 65535]\n";
+    static enum packet_type_e {
+        unknown,
+        ipv4_tcp, ipv4_tcp_data, ipv4_udp_data,
+        ipv6_tcp, ipv6_tcp_data, ipv6_udp_data
+    } packet_type;
     int i, should_reinject, should_recalc_checksum = 0;
     int opt;
+    int packet_v4, packet_v6;
     HANDLE w_filter = NULL;
     WINDIVERT_ADDRESS addr;
     char packet[MAX_PACKET_SIZE];
@@ -257,6 +286,7 @@ int main(int argc, char *argv[]) {
     UINT packetLen;
     UINT packet_dataLen;
     PWINDIVERT_IPHDR ppIpHdr;
+    PWINDIVERT_IPV6HDR ppIpV6Hdr;
     PWINDIVERT_TCPHDR ppTcpHdr;
     PWINDIVERT_UDPHDR ppUdpHdr;
     conntrack_info_t dns_conn_info;
@@ -267,12 +297,16 @@ int main(int argc, char *argv[]) {
         do_fragment_https = 0, do_host = 0,
         do_host_removespace = 0, do_additional_space = 0,
         do_http_allports = 0,
-        do_host_mixedcase = 0, do_dns_redirect = 0,
+        do_host_mixedcase = 0,
+        do_dnsv4_redirect = 0, do_dnsv6_redirect = 0,
         do_dns_verb = 0, do_blacklist = 0;
-    int http_fragment_size = 2;
-    int https_fragment_size = 2;
-    uint32_t dns_addr = 0;
-    uint16_t dns_port = htons(53);
+    unsigned int http_fragment_size = 2;
+    unsigned int https_fragment_size = 2;
+    uint32_t dnsv4_addr = 0;
+    struct in6_addr dnsv6_addr = {0};
+    struct in6_addr dns_temp_addr = {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;
@@ -280,17 +314,35 @@ int main(int argc, char *argv[]) {
     char *hdr_name_addr = NULL, *hdr_value_addr = NULL;
     int hdr_value_len;
 
-    if (filter_string == NULL) {
-        filter_string = malloc(strlen(filter_string_template) + 1);
-        strcpy(filter_string, filter_string_template);
+    if (!running_from_service) {
+        running_from_service = 1;
+        if (service_register(argc, argv)) {
+            /* We've been called as a service. Register service
+             * and exit this thread. main() would be called from
+             * service.c next time.
+             *
+             * Note that if service_register() succeedes it does
+             * not return until the service is stopped.
+             * That is why we should set running_from_service
+             * before calling service_register and unset it
+             * afterwards.
+             */
+            return 0;
+        }
+        running_from_service = 0;
     }
 
+    if (filter_string == NULL)
+        filter_string = strdup(filter_string_template);
+
     printf("GoodbyeDPI: Passive DPI blocker and Active DPI circumvention utility\n");
 
     if (argc == 1) {
         /* enable mode -1 by default */
         do_passivedpi = do_host = do_host_removespace \
-            = do_fragment_http = do_fragment_https = 1;
+                = do_fragment_http = do_fragment_https \
+                = do_fragment_http_persistent \
+                = do_fragment_http_persistent_nowait = 1;
     }
 
     while ((opt = getopt_long(argc, argv, "1234prsaf:e:mwk:n", long_options, NULL)) != -1) {
@@ -347,7 +399,7 @@ int main(int argc, char *argv[]) {
                 do_fragment_https = 1;
                 https_fragment_size = atoi(optarg);
                 if (https_fragment_size <= 0 || https_fragment_size > 65535) {
-                    printf(fragment_size_message);
+                    puts("Fragment size should be in range [0 - 65535]\n");
                     exit(EXIT_FAILURE);
                 }
                 break;
@@ -366,33 +418,70 @@ int main(int argc, char *argv[]) {
                 i = 0;
                 break;
             case 'd':
-                if (!do_dns_redirect) {
-                    do_dns_redirect = 1;
-                    dns_addr = inet_addr(optarg);
-                    if (!dns_addr) {
-                        printf("DNS address parameter error!\n");
+                if ((inet_pton(AF_INET, optarg, dns_temp_addr.s6_addr) == 1) &&
+                    !do_dnsv4_redirect)
+                {
+                    do_dnsv4_redirect = 1;
+                    if (inet_pton(AF_INET, optarg, &dnsv4_addr) != 1) {
+                        puts("DNS address parameter error!");
                         exit(EXIT_FAILURE);
                     }
                     add_filter_str(IPPROTO_UDP, 53);
                     flush_dns_cache();
+                    break;
                 }
+                puts("DNS address parameter error!");
+                exit(EXIT_FAILURE);
+                break;
+            case '!':
+                if ((inet_pton(AF_INET6, optarg, dns_temp_addr.s6_addr) == 1) &&
+                    !do_dnsv6_redirect)
+                {
+                    do_dnsv6_redirect = 1;
+                    if (inet_pton(AF_INET6, optarg, dnsv6_addr.s6_addr) != 1) {
+                        puts("DNS address parameter error!");
+                        exit(EXIT_FAILURE);
+                    }
+                    add_filter_str(IPPROTO_UDP, 53);
+                    flush_dns_cache();
+                    break;
+                }
+                puts("DNS address parameter error!");
+                exit(EXIT_FAILURE);
                 break;
             case 'g':
-                if (!do_dns_redirect) {
-                    printf("--dns-port should be used with --dns-addr!\n"
+                if (!do_dnsv4_redirect) {
+                    puts("--dns-port should be used with --dns-addr!\n"
                         "Make sure you use --dns-addr and pass it before "
-                        "--dns-port\n");
+                        "--dns-port");
                     exit(EXIT_FAILURE);
                 }
-                dns_port = atoi(optarg);
+                dnsv4_port = atoi(optarg);
                 if (atoi(optarg) <= 0 || atoi(optarg) > 65535) {
-                    printf("DNS port parameter error!\n");
+                    puts("DNS port parameter error!");
                     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 = ntohs(dns_port);
+                dnsv4_port = htons(dnsv4_port);
+                break;
+            case '@':
+                if (!do_dnsv6_redirect) {
+                    puts("--dnsv6-port should be used with --dnsv6-addr!\n"
+                        "Make sure you use --dnsv6-addr and pass it before "
+                        "--dnsv6-port");
+                    exit(EXIT_FAILURE);
+                }
+                dnsv6_port = atoi(optarg);
+                if (atoi(optarg) <= 0 || atoi(optarg) > 65535) {
+                    puts("DNS port parameter error!");
+                    exit(EXIT_FAILURE);
+                }
+                if (dnsv6_port != 53) {
+                    add_filter_str(IPPROTO_UDP, dnsv6_port);
+                }
+                dnsv6_port = htons(dnsv6_port);
                 break;
             case 'v':
                 do_dns_verb = 1;
@@ -405,7 +494,7 @@ 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"
@@ -416,17 +505,19 @@ 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);
         }
     }
@@ -434,12 +525,14 @@ int main(int argc, char *argv[]) {
     printf("Block passive: %d, Fragment HTTP: %d, Fragment persistent HTTP: %d, "
            "Fragment HTTPS: %d, "
            "hoSt: %d, Host no space: %d, Additional space: %d, Mix Host: %d, "
-           "HTTP AllPorts: %d, HTTP Persistent Nowait: %d, DNS redirect: %d\n",
+           "HTTP AllPorts: %d, HTTP Persistent Nowait: %d, DNS redirect: %d, "
+           "DNSv6 redirect: %d\n",
            do_passivedpi, (do_fragment_http ? http_fragment_size : 0),
            (do_fragment_http_persistent ? http_fragment_size : 0),
            (do_fragment_https ? https_fragment_size : 0),
            do_host, do_host_removespace, do_additional_space, do_host_mixedcase,
-           do_http_allports, do_fragment_http_persistent_nowait, do_dns_redirect
+           do_http_allports, do_fragment_http_persistent_nowait, do_dnsv4_redirect,
+           do_dnsv6_redirect
           );
 
     if (do_fragment_http && http_fragment_size > 2) {
@@ -452,18 +545,18 @@ int main(int argc, char *argv[]) {
     filter_num = 0;
 
     if (do_passivedpi) {
-        /* IPv4 filter for inbound RST packets with ID = 0 or 1 */
+        /* IPv4 only filter for inbound RST packets with ID = 0 or 1 */
         filters[filter_num] = init(
             "inbound and ip and tcp and "
-            "(ip.Id == 0x0001 or ip.Id == 0x0000) and "
+            "(ip.Id >= 0x0000 and ip.Id <= 0x000F) and "
             "(tcp.SrcPort == 443 or tcp.SrcPort == 80) and tcp.Rst and "
-            DIVERT_NO_LOCALNETS_SRC,
+            DIVERT_NO_LOCALNETSv4_SRC,
             WINDIVERT_FLAG_DROP);
         filter_num++;
     }
 
     /* 
-     * IPv4 filter for inbound HTTP redirection packets and
+     * IPv4 & IPv6 filter for inbound HTTP redirection packets and
      * active DPI circumvention
      */
     filters[filter_num] = init(filter_string, 0);
@@ -481,13 +574,53 @@ int main(int argc, char *argv[]) {
 
     while (1) {
         if (WinDivertRecv(w_filter, packet, sizeof(packet), &addr, &packetLen)) {
-            //printf("Got %s packet, len=%d!\n", addr.Direction ? "inbound" : "outbound",
-            //       packetLen);
+            debug("Got %s packet, len=%d!\n", addr.Direction ? "inbound" : "outbound",
+                   packetLen);
             should_reinject = 1;
             should_recalc_checksum = 0;
 
-            if (WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
-                NULL, NULL, NULL, &ppTcpHdr, NULL, &packet_data, &packet_dataLen)) {
+            ppIpHdr = (PWINDIVERT_IPHDR)NULL;
+            ppIpV6Hdr = (PWINDIVERT_IPV6HDR)NULL;
+            ppTcpHdr = (PWINDIVERT_TCPHDR)NULL;
+            ppUdpHdr = (PWINDIVERT_UDPHDR)NULL;
+            packet_v4 = packet_v6 = 0;
+            packet_type = unknown;
+
+            // Parse network packet and set it's type
+            if ((packet_v4 = WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
+                NULL, NULL, NULL, &ppTcpHdr, NULL, &packet_data, &packet_dataLen)))
+            {
+                packet_type = ipv4_tcp_data;
+            }
+            else if ((packet_v6 = WinDivertHelperParsePacket(packet, packetLen, NULL,
+                &ppIpV6Hdr, NULL, NULL, &ppTcpHdr, NULL, &packet_data, &packet_dataLen)))
+            {
+                packet_type = ipv6_tcp_data;
+            }
+            else if ((packet_v4 = WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
+                NULL, NULL, NULL, &ppTcpHdr, NULL, NULL, NULL)))
+            {
+                packet_type = ipv4_tcp;
+            }
+            else if ((packet_v6 = WinDivertHelperParsePacket(packet, packetLen, NULL,
+                &ppIpV6Hdr, NULL, NULL, &ppTcpHdr, NULL, NULL, NULL)))
+            {
+                packet_type = ipv6_tcp;
+            }
+            else if ((packet_v4 = WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
+                NULL, NULL, NULL, NULL, &ppUdpHdr, &packet_data, &packet_dataLen)))
+            {
+                packet_type = ipv4_udp_data;
+            }
+            else if ((packet_v6 = WinDivertHelperParsePacket(packet, packetLen, NULL,
+                &ppIpV6Hdr, NULL, NULL, NULL, &ppUdpHdr, &packet_data, &packet_dataLen)))
+            {
+                packet_type = ipv6_udp_data;
+            }
+
+            debug("packet_type: %d, packet_v4: %d, packet_v6: %d\n", packet_type, packet_v4, packet_v6);
+
+            if (packet_type == ipv4_tcp_data || packet_type == ipv6_tcp_data) {
                 //printf("Got parsed packet, len=%d!\n", packet_dataLen);
                 /* Got a TCP packet WITH DATA */
 
@@ -533,11 +666,20 @@ int main(int argc, char *argv[]) {
                          * ack number of received packet and retransmitting missing part again,
                          * but it's better to send it anyway since it eliminates one RTT.
                          */
-                        if (do_fragment_http_persistent && !http_req_fragmented) {
-                            ppIpHdr->Length = htons(
-                                ntohs(ppIpHdr->Length) -
-                                packet_dataLen + http_fragment_size
-                            );
+                        if (do_fragment_http_persistent && !http_req_fragmented &&
+                            (packet_dataLen > http_fragment_size))
+                        {
+                            if (packet_v4)
+                                ppIpHdr->Length = htons(
+                                    ntohs(ppIpHdr->Length) -
+                                    packet_dataLen + http_fragment_size
+                                );
+                            else if (packet_v6)
+                                ppIpV6Hdr->Length = htons(
+                                    ntohs(ppIpV6Hdr->Length) -
+                                    packet_dataLen + http_fragment_size
+                                );
+
                             WinDivertHelperCalcChecksums(
                                 packet, packetLen - packet_dataLen + http_fragment_size, 0
                             );
@@ -546,11 +688,18 @@ int main(int argc, char *argv[]) {
                                 packetLen - packet_dataLen + http_fragment_size,
                                 &addr, NULL
                             );
+
                             if (do_fragment_http_persistent_nowait) {
-                                ppIpHdr->Length = htons(
-                                    ntohs(ppIpHdr->Length) -
-                                    http_fragment_size + packet_dataLen - http_fragment_size
-                                );
+                                if (packet_v4)
+                                    ppIpHdr->Length = htons(
+                                        ntohs(ppIpHdr->Length) -
+                                        http_fragment_size + packet_dataLen - http_fragment_size
+                                    );
+                                else if (packet_v6)
+                                    ppIpV6Hdr->Length = htons(
+                                        ntohs(ppIpV6Hdr->Length) -
+                                        http_fragment_size + packet_dataLen - http_fragment_size
+                                    );
                                 memmove(packet_data,
                                         packet_data + http_fragment_size,
                                         packet_dataLen);
@@ -647,8 +796,7 @@ int main(int argc, char *argv[]) {
             } /* Handle TCP packet with data */
 
             /* Else if we got TCP packet without data */
-            else if (WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
-                NULL, NULL, NULL, &ppTcpHdr, NULL, NULL, NULL)) {
+            else if (packet_type == ipv4_tcp || packet_type == ipv6_tcp) {
                 /* If we got INBOUND SYN+ACK packet */
                 if (addr.Direction == WINDIVERT_DIRECTION_INBOUND &&
                     ppTcpHdr->Syn == 1 && ppTcpHdr->Ack == 1) {
@@ -658,28 +806,35 @@ int main(int argc, char *argv[]) {
                      * is enabled as there could be non-HTTP data on port 80
                      */
                     if (do_fragment_http && ppTcpHdr->SrcPort == htons(80)) {
-                        change_window_size(packet, http_fragment_size);
+                        change_window_size(ppTcpHdr, http_fragment_size);
                         should_recalc_checksum = 1;
                     }
                     else if (do_fragment_https && ppTcpHdr->SrcPort != htons(80)) {
-                        change_window_size(packet, https_fragment_size);
+                        change_window_size(ppTcpHdr, https_fragment_size);
                         should_recalc_checksum = 1;
                     }
                 }
             }
 
             /* Else if we got UDP packet with data */
-            else if (do_dns_redirect && WinDivertHelperParsePacket(packet, packetLen, &ppIpHdr,
-                NULL, NULL, NULL, NULL, &ppUdpHdr, &packet_data, &packet_dataLen)) {
-
+            else if ((do_dnsv4_redirect && (packet_type == ipv4_udp_data)) ||
+                     (do_dnsv6_redirect && (packet_type == ipv6_udp_data)))
+            {
                 if (addr.Direction == WINDIVERT_DIRECTION_INBOUND) {
-                    if (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, 1)))
                     {
                         /* Changing source IP and port to the values
                          * from DNS conntrack */
-                        ppIpHdr->SrcAddr = dns_conn_info.dstip;
+                        if (packet_v4)
+                            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;
@@ -696,14 +851,24 @@ int main(int argc, char *argv[]) {
                 }
 
                 else if (addr.Direction == WINDIVERT_DIRECTION_OUTBOUND) {
-                    if (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, 1)))
                     {
                         /* Changing destination IP and port to the values
                          * from configuration */
-                        ppIpHdr->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, (uint32_t*)dnsv6_addr.s6_addr);
+                            ppUdpHdr->DstPort = dnsv6_port;
+                        }
                         should_recalc_checksum = 1;
                     }
                     else {

goodbyedpi.h

@@ -5,3 +5,6 @@
 #else
 #define debug(...) printf(__VA_ARGS__)
 #endif
+
+int main(int argc, char *argv[]);
+void deinit_all();

service.c

@@ -0,0 +1,96 @@
+#include <windows.h>
+#include <stdio.h>
+#include "goodbyedpi.h"
+#include "service.h"
+
+#define SERVICE_NAME "GoodbyeDPI"
+
+static SERVICE_STATUS ServiceStatus;
+static SERVICE_STATUS_HANDLE hStatus;
+static int service_argc = 0;
+static char **service_argv = NULL;
+
+int service_register(int argc, char *argv[])
+{
+    int i, ret;
+    SERVICE_TABLE_ENTRY ServiceTable[] = {
+        {SERVICE_NAME, (LPSERVICE_MAIN_FUNCTION)service_main},
+        {NULL, NULL}
+    };
+    /*
+     * Save argc & argv as service_main is called with different
+     * arguments, which are passed from "start" command, not
+     * from the program command line.
+     * We don't need this behaviour.
+     *
+     * Note that if StartServiceCtrlDispatcher() succeedes
+     * it does not return until the service is stopped,
+     * so we should copy all arguments first and then
+     * handle the failure.
+     */
+    if (!service_argc && !service_argv) {
+        service_argc = argc;
+        service_argv = malloc(sizeof(void*) * argc);
+        for (i = 0; i < argc; i++) {
+            service_argv[i] = strdup(argv[i]);
+        }
+    }
+
+    ret = StartServiceCtrlDispatcher(ServiceTable);
+
+    if (service_argc && service_argv) {
+        for (i = 0; i < service_argc; i++) {
+            free(service_argv[i]);
+        }
+        free(service_argv);
+    }
+
+    return ret;
+}
+
+void service_main(int argc __attribute__((unused)),
+                  char *argv[] __attribute__((unused)))
+{
+    ServiceStatus.dwServiceType = SERVICE_WIN32_OWN_PROCESS; 
+    ServiceStatus.dwCurrentState = SERVICE_RUNNING;
+    ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
+    ServiceStatus.dwWin32ExitCode = 0;
+    ServiceStatus.dwServiceSpecificExitCode = 0;
+    ServiceStatus.dwCheckPoint = 1;
+    ServiceStatus.dwWaitHint = 0;
+
+    hStatus = RegisterServiceCtrlHandler(
+        SERVICE_NAME,
+        (LPHANDLER_FUNCTION)service_controlhandler);
+    if (hStatus == (SERVICE_STATUS_HANDLE)0)
+    {
+        // Registering Control Handler failed
+        return;
+    }
+
+    SetServiceStatus(hStatus, &ServiceStatus);
+
+    // Calling main with saved argc & argv
+    ServiceStatus.dwWin32ExitCode = main(service_argc, service_argv);
+    ServiceStatus.dwCurrentState  = SERVICE_STOPPED;
+    SetServiceStatus(hStatus, &ServiceStatus);
+    return;
+}
+
+// Control handler function
+void service_controlhandler(DWORD request)
+{
+    switch(request)
+    {
+        case SERVICE_CONTROL_STOP:
+        case SERVICE_CONTROL_SHUTDOWN:
+            deinit_all();
+            ServiceStatus.dwWin32ExitCode = 0;
+            ServiceStatus.dwCurrentState  = SERVICE_STOPPED;
+        default:
+            break;
+    }
+    // Report current status
+    SetServiceStatus(hStatus, &ServiceStatus);
+    return;
+}

service.h

@@ -0,0 +1,3 @@
+int service_register();
+void service_main(int argc, char *argv[]);
+void service_controlhandler(DWORD request);