Windows Service support.

Program can now be started as a Windows Service. No additional
arguments needed. Refer to `service_install` and `service_remove`
scripts in released zip file.

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
 

goodbyedpi.c

@@ -11,6 +11,7 @@
 #include <getopt.h>
 #include "windivert.h"
 #include "goodbyedpi.h"
+#include "service.h"
 #include "dnsredir.h"
 #include "blackwhitelist.h"
 
@@ -20,9 +21,6 @@
 
 #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 "(" \
                    "(ip.DstAddr < 127.0.0.1 or ip.DstAddr > 127.255.255.255) and " \
@@ -41,13 +39,13 @@
 
 #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_message); \
             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 +53,7 @@
     } \
 } 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 ";
@@ -147,7 +146,7 @@ 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 +215,9 @@ 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);
     }
 }
 
@@ -246,7 +245,7 @@ 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[] =
+    static const char *fragment_size_message =
                 "Fragment size should be in range [0 - 65535]\n";
     int i, should_reinject, should_recalc_checksum = 0;
     int opt;
@@ -269,8 +268,8 @@ int main(int argc, char *argv[]) {
         do_http_allports = 0,
         do_host_mixedcase = 0, do_dns_redirect = 0,
         do_dns_verb = 0, do_blacklist = 0;
-    int http_fragment_size = 2;
-    int https_fragment_size = 2;
+    unsigned int http_fragment_size = 2;
+    unsigned int https_fragment_size = 2;
     uint32_t dns_addr = 0;
     uint16_t dns_port = htons(53);
     char *host_addr, *useragent_addr, *method_addr;
@@ -280,6 +279,15 @@ int main(int argc, char *argv[]) {
     char *hdr_name_addr = NULL, *hdr_value_addr = NULL;
     int hdr_value_len;
 
+    if (!running_from_service && 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.
+         */
+        running_from_service = 1;
+        return 0;
+    }
+
     if (filter_string == NULL) {
         filter_string = malloc(strlen(filter_string_template) + 1);
         strcpy(filter_string, filter_string_template);
@@ -290,7 +298,9 @@ int main(int argc, char *argv[]) {
     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 +357,7 @@ 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_message);
                     exit(EXIT_FAILURE);
                 }
                 break;
@@ -533,7 +543,9 @@ 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) {
+                        if (do_fragment_http_persistent && !http_req_fragmented &&
+                            (packet_dataLen > http_fragment_size)
+                        ) {
                             ppIpHdr->Length = htons(
                                 ntohs(ppIpHdr->Length) -
                                 packet_dataLen + http_fragment_size
@@ -658,11 +670,11 @@ 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;
                     }
                 }

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 +1,83 @@
+#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;
+static char **service_argv;
+
+int service_register(int argc, char *argv[])
+{
+    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.
+     */
+    service_argc = argc;
+    service_argv = malloc(sizeof(void*) * argc);
+    for (int i = 0; i < argc; i++) {
+        service_argv[i] = strdup(argv[i]);
+    }
+    return StartServiceCtrlDispatcher(ServiceTable);
+}
+
+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
+    main(service_argc, service_argv);
+
+    if (ServiceStatus.dwCurrentState != SERVICE_STOPPED) {
+        // If terminated with error
+        ServiceStatus.dwWin32ExitCode = 1;
+        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);