winws: ssid-filter

docs/windows.eng.md

@@ -49,6 +49,7 @@ Task of `iptables` is done inside `winws` through `windivert` filters. `Windiver
  --wf-udp=[~]port1[-port2]                      ; UDP port filter. ~ means negation. multiple comma separated values allowed.
  --wf-raw=<filter>|@<filename>                  ; raw windivert filter string or filename
  --wf-save=<filename>                           ; save windivert filter string to a file and exit
+ --ssid-filter=ssid1[,ssid2,ssid3,...]          ; enable winws only if any of specified wifi SSIDs connected
 ```
 
 `--wf-l3`, `--wf-tcp`, `--wf-udp` can take multiple comma separated arguments.
@@ -59,6 +60,8 @@ If you can't find index this way use `winws --debug` to see index there. Subinte
 
 Multiple `winws` processes are allowed. However, it's discouraged to intersect their filters.
 
+`--ssid-filter` allows to enable `winws` only if specified wifi networks are connected. `winws` auto detects SSID appearance and disappearance.
+
 `Cygwin` shell does not run binaries if their directory has it's own copy of `cygwin1.dll`.
 That's why exists separate standalone version in `binaries/win64/zapret-tpws`.
 `Cygwin` is required for `blockcheck.sh` support but `winws` itself can be run standalone without cygwin.

docs/windows.txt

@@ -55,6 +55,7 @@ https://learn.microsoft.com/en-us/security-updates/SecurityAdvisories/2015/30339
  --wf-udp=[~]port1[-port2]		; фильтр портов для udp. ~ означает отрицание
  --wf-raw=<filter>|@<filename>		; задать напрямую фильтр windivert из параметра или из файла. имени файла предшествует символ @.
  --wf-save=<filename>			; сохранить сконструированный фильтр windivert в файл для последующей правки вручную
+ --ssid-filter=ssid1[,ssid2,ssid3,...]  ; включать winws только когда подключена любая из указанных wifi сетей
 
 Параметры --wf-l3, --wf-tcp, --wf-udp могут брать несколько значений через запятую.
 
@@ -70,6 +71,10 @@ autottl и autohostlist. При включении autohostlist так же пе
 
 Можно запускать несколько процессов winws с разными стратегиями. Однако, не следует делать пересекающиеся фильтры.
 
+В --ssid-filter можно через запятую задать неограниченное количество имен wifi сетей (SSID). Если задана хотя бы одна сеть,
+то winws включается только, если подключен указанный SSID. Если SSID исчезает, winws отключается. Если SSID появляется снова,
+winws включается. Это нужно, чтобы можно было применять раздельное дурение к каждой отдельной wifi сети.
+
 Если в путях присутствуют национальные символы, то при вызове winws из cmd или bat кодировку нужно использовать OEM.
 Для русского языка это 866. Пути с пробелами нужно брать в кавычки.
 

nfq/Makefile

@@ -5,7 +5,7 @@ CFLAGS_MAC = -mmacosx-version-min=10.8
 CFLAGS_CYGWIN = -Wno-address-of-packed-member -static
 LIBS_LINUX = -lnetfilter_queue -lnfnetlink -lz
 LIBS_BSD = -lz
-LIBS_CYGWIN = -lz -Lwindivert -lwindivert
+LIBS_CYGWIN = -lz -Lwindivert -lwindivert -lwlanapi
 SRC_FILES = *.c crypto/*.c
 
 all: nfqws

nfq/crypto/aes-gcm.h

@@ -2,5 +2,5 @@
 
 #include "gcm.h"  
 
-// mode : ENCRYPT, DECRYPT
+// mode : AES_ENCRYPT, AES_DECRYPT
 int aes_gcm_crypt(int mode, uint8_t *output, const uint8_t *input, size_t input_length, const uint8_t *key, const size_t key_len, const uint8_t *iv, const size_t iv_len, const uint8_t *adata, size_t adata_len, uint8_t *atag, size_t atag_len);

nfq/crypto/aes.h

@@ -28,8 +28,8 @@
 
 #include <string.h>
 
-#define ENCRYPT         1       // specify whether we're encrypting
+#define AES_ENCRYPT         1       // specify whether we're encrypting
-#define DECRYPT         0       // or decrypting
+#define AES_DECRYPT         0       // or decrypting
 
 #if defined(_MSC_VER)
 #include <basetsd.h>

nfq/crypto/gcm.c

@@ -186,7 +186,7 @@ int gcm_setkey(gcm_context *ctx,   // pointer to caller-provided gcm context
 
 	// encrypt the null 128-bit block to generate a key-based value
 	// which is then used to initialize our GHASH lookup tables
-	if ((ret = aes_setkey(&ctx->aes_ctx, ENCRYPT, key, keysize)) != 0)
+	if ((ret = aes_setkey(&ctx->aes_ctx, AES_ENCRYPT, key, keysize)) != 0)
 		return(ret);
 	if ((ret = aes_cipher(&ctx->aes_ctx, h, h)) != 0)
 		return(ret);
@@ -266,7 +266,7 @@ int gcm_start(gcm_context *ctx,    // pointer to user-provided GCM context
 	ctx->add_len = 0;
 
 	ctx->mode = mode;               // set the GCM encryption/decryption mode
-	ctx->aes_ctx.mode = ENCRYPT;    // GCM *always* runs AES in ENCRYPTION mode
+	ctx->aes_ctx.mode = AES_ENCRYPT;    // GCM *always* runs AES in ENCRYPTION mode
 
 	if (iv_len == 12) {                // GCM natively uses a 12-byte, 96-bit IV
 		memcpy(ctx->y, iv, iv_len);   // copy the IV to the top of the 'y' buff
@@ -338,7 +338,7 @@ int gcm_update(gcm_context *ctx,       // pointer to user-provided GCM context
 			return(ret);
 
 		// encrypt or decrypt the input to the output
-		if (ctx->mode == ENCRYPT)
+		if (ctx->mode == AES_ENCRYPT)
 		{
 			for (i = 0; i < use_len; i++) {
 				// XOR the cipher's ouptut vector (ectr) with our input
@@ -481,7 +481,7 @@ int gcm_auth_decrypt(
 	   (which is an identical XORing to reverse the previous one)
 	   and also to re-generate the matching authentication tag
 	*/
-	gcm_crypt_and_tag(ctx, DECRYPT, iv, iv_len, add, add_len,
+	gcm_crypt_and_tag(ctx, AES_DECRYPT, iv, iv_len, add, add_len,
 		input, output, length, check_tag, tag_len);
 
 	// now we verify the authentication tag in 'constant time'

nfq/darkmagic.c

@@ -14,6 +14,9 @@
 #include "params.h"
 #include "nfqws.h"
 
+#ifdef __CYGWIN__
+#include <wlanapi.h>
+#endif
 
 uint32_t net32_add(uint32_t netorder_value, uint32_t cpuorder_increment)
 {
@@ -959,8 +962,83 @@ void tcp_rewrite_winsize(struct tcphdr *tcp, uint16_t winsize, uint8_t scale_fac
 
 static HANDLE w_filter = NULL;
 static OVERLAPPED ovl = { .hEvent = NULL };
+static const struct str_list_head *wlan_filter_ssid = NULL;
+static DWORD wlan_filter_tick=0;
 uint32_t w_win32_error=0;
 
+bool wlan_filter_match(const struct str_list_head *ssid_list)
+{
+	DWORD dwCurVersion;
+	HANDLE hClient = NULL;
+	PWLAN_INTERFACE_INFO_LIST pIfList = NULL;
+	PWLAN_INTERFACE_INFO pIfInfo;
+	PWLAN_CONNECTION_ATTRIBUTES pConnectInfo;
+	DWORD connectInfoSize, k;
+	bool bRes;
+	struct str_list *ssid;
+	size_t len;
+
+	// no filter given. always matches.
+	if (!ssid_list || LIST_EMPTY(ssid_list))
+	{
+		w_win32_error = 0;
+		return true;
+	}
+
+	w_win32_error = WlanOpenHandle(2, NULL, &dwCurVersion, &hClient);
+	if (w_win32_error != ERROR_SUCCESS) goto fail;
+	w_win32_error = WlanEnumInterfaces(hClient, NULL, &pIfList);
+	if (w_win32_error != ERROR_SUCCESS) goto fail;
+	for (k = 0; k < pIfList->dwNumberOfItems; k++)
+	{
+		pIfInfo = pIfList->InterfaceInfo + k;
+		if (pIfInfo->isState == wlan_interface_state_connected)
+		{
+			w_win32_error = WlanQueryInterface(hClient,
+				&pIfInfo->InterfaceGuid,
+				wlan_intf_opcode_current_connection,
+				NULL,
+				&connectInfoSize,
+				(PVOID *)&pConnectInfo,
+				NULL);
+			if (w_win32_error != ERROR_SUCCESS) goto fail;
+
+//			printf("%s\n", pConnectInfo->wlanAssociationAttributes.dot11Ssid.ucSSID);
+
+			LIST_FOREACH(ssid, ssid_list, next)
+			{
+				len = strlen(ssid->str);
+				if (len==pConnectInfo->wlanAssociationAttributes.dot11Ssid.uSSIDLength && !memcmp(ssid->str,pConnectInfo->wlanAssociationAttributes.dot11Ssid.ucSSID,len))
+				{	
+					WlanFreeMemory(pConnectInfo);
+					goto found;
+				}
+			}
+
+			WlanFreeMemory(pConnectInfo);
+		}
+	}
+	w_win32_error = 0;
+fail:
+	bRes = false;
+ex:
+	if (pIfList) WlanFreeMemory(pIfList);
+	if (hClient) WlanCloseHandle(hClient, 0);
+	return bRes;
+found:
+	w_win32_error = 0;
+	bRes = true;
+	goto ex;
+}
+
+static bool wlan_filter_match_rate_limited(void)
+{
+	DWORD dwTick = GetTickCount() / 1000;
+	if (wlan_filter_tick == dwTick) return true;
+	wlan_filter_tick = dwTick;
+	return wlan_filter_match(wlan_filter_ssid);
+}
+
 static HANDLE windivert_init_filter(const char *filter, UINT64 flags)
 {
 	LPSTR errormessage = NULL;
@@ -1006,8 +1084,9 @@ void rawsend_cleanup(void)
 		CloseHandle(ovl.hEvent);
 		ovl.hEvent=NULL;
 	}
+	wlan_filter_ssid = NULL;
 }
-bool windivert_init(const char *filter)
+bool windivert_init(const char *filter, const struct str_list_head *ssid_filter)
 {
 	rawsend_cleanup();
 	w_filter = windivert_init_filter(filter, 0);
@@ -1020,6 +1099,7 @@ bool windivert_init(const char *filter)
 			rawsend_cleanup();
 			return false;
 		}
+		wlan_filter_ssid = ssid_filter;
 		return true;
 	}
 	return false;
@@ -1037,6 +1117,11 @@ static bool windivert_recv_filter(HANDLE hFilter, uint8_t *packet, size_t *len,
 		errno=EINTR;
 		return false;
 	}
+	if (!wlan_filter_match_rate_limited())
+	{
+		errno=ENODEV;
+		return false;
+	}
 	usleep(0);
 	if (WinDivertRecvEx(hFilter, packet, *len, &recv_len, 0, wa, NULL, &ovl))
 	{
@@ -1057,6 +1142,11 @@ static bool windivert_recv_filter(HANDLE hFilter, uint8_t *packet, size_t *len,
 						errno=EINTR;
 						return false;
 					}
+					if (!wlan_filter_match_rate_limited())
+					{
+						errno=ENODEV;
+						return false;
+					}
 					usleep(0);
 				}
 				if (!GetOverlappedResult(hFilter,&ovl,&rd,TRUE))

nfq/darkmagic.h

@@ -18,6 +18,7 @@
 #endif
 
 #include "packet_queue.h"
+#include "pools.h"
 
 #ifndef IPPROTO_DIVERT
 #define IPPROTO_DIVERT 258
@@ -151,9 +152,10 @@ bool tcp_has_fastopen(const struct tcphdr *tcp);
 #ifdef __CYGWIN__
 extern uint32_t w_win32_error;
 
-bool windivert_init(const char *filter);
+bool windivert_init(const char *filter, const struct str_list_head *ssid_filter);
 bool windivert_recv(uint8_t *packet, size_t *len, WINDIVERT_ADDRESS *wa);
 bool windivert_send(const uint8_t *packet, size_t len, const WINDIVERT_ADDRESS *wa);
+bool wlan_filter_match(const struct str_list_head *ssid_list);
 #else
 // should pre-do it if dropping privileges. otherwise its not necessary
 bool rawsend_preinit(bool bind_fix4, bool bind_fix6);

nfq/nfqws.c

@@ -410,13 +410,33 @@ static int win_main(const char *windivert_filter)
 	WINDIVERT_ADDRESS wa;
 	char ifout[22];
 
-	if (!windivert_init(windivert_filter))
+	pre_desync();
+
+	for(;;)
+	{
+		if (!wlan_filter_match(&params.ssid_filter))
+		{
+			printf("logical network is not present. waiting it to appear.\n");
+			fflush(stdout);
+			do
+			{
+				if (bQuit)
+				{
+					DLOG("QUIT requested\n")
+					return 0;
+				}
+				usleep(500000);
+			}
+			while (!wlan_filter_match(&params.ssid_filter));
+			printf("logical network now present\n");
+			fflush(stdout);
+		}
+
+		if (!windivert_init(windivert_filter, &params.ssid_filter))
 			return w_win32_error;
 
 		printf("windivert initialized. capture is started.\n");
 
-	pre_desync();
-
 		// cygwin auto flush fails when piping
 		fflush(stdout);
 		fflush(stderr);
@@ -431,10 +451,16 @@ static int win_main(const char *windivert_filter)
 					DLOG("windivert: ignoring too large packet\n")
 					continue; // too large packet
 				}
+				else if (errno==ENODEV)
+				{
+					printf("logical network disappeared. deinitializing windivert.\n");
+					rawsend_cleanup();
+					break;
+				}
 				else if (errno==EINTR)
 				{
 					DLOG("QUIT requested\n")
-				break;
+					return 0;
 				}
 				fprintf(stderr, "windivert: recv failed. errno %d\n", errno);
 				return w_win32_error;
@@ -477,6 +503,7 @@ static int win_main(const char *windivert_filter)
 			fflush(stdout);
 			fflush(stderr);
 		}
+	}
 	return 0;
 }
 
@@ -521,6 +548,9 @@ static void cleanup_params(void)
 	StrPoolDestroy(&params.hostlist_exclude);
 	StrPoolDestroy(&params.hostlist);
 	HostFailPoolDestroy(&params.hostlist_auto_fail_counters);
+#ifdef __CYGWIN__
+	strlist_destroy(&params.ssid_filter);
+#endif
 }
 static void exit_clean(int code)
 {
@@ -760,6 +790,8 @@ static void exithelp(void)
 		" --wf-udp=[~]port1[-port2]\t\t\t; UDP port filter. ~ means negation. multiple comma separated values allowed.\n"
 		" --wf-raw=<filter>|@<filename>\t\t\t; raw windivert filter string or filename\n"
 		" --wf-save=<filename>\t\t\t\t; save windivert filter string to a file and exit\n"
+		"\nLOGICAL NETWORK FILTER:\n"
+		" --ssid-filter=ssid1[,ssid2,ssid3,...]\t\t; enable winws only if any of specified wifi SSIDs connected\n"
 #endif
 		"\nHOSTLIST FILTER:\n"
 		" --hostlist=<filename>\t\t\t\t; apply dpi desync only to the listed hosts (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)\n"
@@ -915,7 +947,9 @@ int main(int argc, char **argv)
 	LIST_INIT(&params.hostlist_files);
 	LIST_INIT(&params.hostlist_exclude_files);
 
-#ifndef __CYGWIN__
+#ifdef __CYGWIN__
+	LIST_INIT(&params.ssid_filter);
+#else
 	if (can_drop_root()) // are we root ?
 	{
 		params.uid = params.gid = 0x7FFFFFFF; // default uid:gid
@@ -1002,6 +1036,7 @@ int main(int argc, char **argv)
 		{"wf-udp",required_argument,0,0},	// optidx=53
 		{"wf-raw",required_argument,0,0},	// optidx=54
 		{"wf-save",required_argument,0,0},	// optidx=55
+		{"ssid-filter",required_argument,0,0},	// optidx=56
 #endif
 		{NULL,0,NULL,0}
 	};
@@ -1499,6 +1534,24 @@ int main(int argc, char **argv)
 			strncpy(wf_save_file, optarg, sizeof(wf_save_file));
 			wf_save_file[sizeof(wf_save_file) - 1] = '\0';
 			break;
+		case 56: /* ssid-filter */
+			{
+				char *e,*p = optarg;
+				while (p)
+				{
+					e = strchr(p,',');
+					if (e) *e++=0;
+					if (*p && !strlist_add(&params.ssid_filter, p))
+					{
+						fprintf(stderr, "strlist_add failed\n");
+						exit_clean(1);
+					}
+					p = e;
+
+				}
+			}
+			break;
+
 #endif
 		}
 	}

nfq/params.h

@@ -65,7 +65,9 @@ struct params_s
 	size_t fake_http_size,fake_tls_size,fake_quic_size,fake_wg_size,fake_dht_size,fake_unknown_size,fake_syndata_size,fake_unknown_udp_size;
 	int udplen_increment;
 
-#ifndef __CYGWIN__
+#ifdef __CYGWIN__
+	struct str_list_head ssid_filter;
+#else
 	bool droproot;
 	uid_t uid;
 	gid_t gid;

nfq/protocol.c

@@ -600,7 +600,7 @@ bool QUICDecryptInitial(const uint8_t *data, size_t data_len, uint8_t *clean, si
 	header[0] = packet0;
 	for(uint8_t i = 0; i < pkn_len; i++) header[header_len - 1 - i] = (uint8_t)(pkn >> (8 * i));
 
-	if (aes_gcm_crypt(DECRYPT, clean, decrypt_begin, cryptlen, aeskey, sizeof(aeskey), aesiv, sizeof(aesiv), header, header_len, atag, sizeof(atag)))
+	if (aes_gcm_crypt(AES_DECRYPT, clean, decrypt_begin, cryptlen, aeskey, sizeof(aeskey), aesiv, sizeof(aesiv), header, header_len, atag, sizeof(atag)))
 		return false;
 
 	// check if message was decrypted correctly : good keys , no data corruption