nfqws: udplen-pattern, hex string support

docs/readme.eng.md

@@ -138,44 +138,47 @@ For BSD systems there is dvtws. Its built from the same source and has almost th
 nfqws takes the following parameters:
 
 ```
- --debug=0|1				; 1=print debug info
+ --debug=0|1
  --qnum=<nfqueue_number>
- --bind-fix4                            ; apply outgoing interface selection fix for generated ipv4 packets
- --bind-fix6                            ; apply outgoing interface selection fix for generated ipv6 packets
- --wsize=<winsize>[:<scale_factor>]	; change window size in SYN,ACK packets. default is not to change scale factor (OBSOLETE !)
- --wssize=<winsize>[:<scale_factor>]	; change window size in outgoing packets. default scale factor is 0. (see CONNTRACK)
- --wssize-cutoff=[n|d|s]N               ; apply server wsize only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N
- --ctrack-timeouts=S:E:F                ; internal conntrack timeouts for SYN, ESTABLISHED and FIN stages. default 60:300:60
- --hostcase           			; change Host: => host:
- --hostspell=HoSt      			; exact spelling of the "Host" header. must be 4 chars. default is "host"
- --hostnospace         			; remove space after Host: and add it to User-Agent: to preserve packet size
- --domcase				; mix domain case after Host: like this : TeSt.cOm
  --daemon                                       ; daemonize
  --pidfile=<filename>                           ; write pid to file
  --user=<username>                              ; drop root privs
  --uid=uid[:gid]                                ; drop root privs
- --dpi-desync=[<mode0,]<mode>[,<mode2>]	; desync dpi state. modes : synack fake fakeknown rst rstack hopbyhop destopt ipfrag1 disorder disorder2 split split2 ipfrag2 udplen
+ --bind-fix4                                    ; apply outgoing interface selection fix for generated ipv4 packets
- --dpi-desync-fwmark=<int|0xHEX>        ; override fwmark for desync packet. default = 0x40000000
+ --bind-fix6                                    ; apply outgoing interface selection fix for generated ipv6 packets
+ --wsize=<window_size>[:<scale_factor>]         ; set window size. 0 = do not modify. OBSOLETE !
+ --wssize=<window_size>[:<scale_factor>]        ; set window size for server. 0 = do not modify. default scale_factor = 0.
+ --wssize-cutoff=[n|d|s]N                       ; apply server wsize only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N
+ --ctrack-timeouts=S:E:F[:U]                    ; internal conntrack timeouts for TCP SYN, ESTABLISHED, FIN stages, UDP timeout. default 60:300:60:60
+ --hostcase                                     ; change Host: => host:
+ --hostspell                                    ; exact spelling of "Host" header. must be 4 chars. default is "host"
+ --hostnospace                                  ; remove space after Host: and add it to User-Agent: to preserve packet size
+ --domcase                                      ; mix domain case : Host: TeSt.cOm
+ --dpi-desync=[<mode0>,]<mode>[,<mode2>]        ; try to desync dpi state. modes : synack fake fakeknown rst rstack hopbyhop destopt ipfrag1 disorder disorder2 split split2 ipfrag2 udplen
+ --dpi-desync-fwmark=<int|0xHEX>                ; override fwmark for desync packet. default = 0x40000000 (1073741824)
  --dpi-desync-ttl=<int>                         ; set ttl for desync packet
- --dpi-desync-ttl6=<int>                ; set ipv6 hop limit for desync packet. by default ttl value is used
+ --dpi-desync-ttl6=<int>                        ; set ipv6 hop limit for desync packet. by default ttl value is used.
- --dpi-desync-fooling=<fooling>		; can take multiple comma separated values : none md5sig badseq badsum hopbyhop hopbyhop2
+ --dpi-desync-fooling=<mode>[,<mode>]           ; can use multiple comma separated values. modes : none md5sig ts badseq badsum hopbyhop hopbyhop2
- --dpi-desync-retrans=0|1               ; (fake,rst,rstack only) 0(default)=reinject original data packet after fake  1=drop original data packet to force its retransmission
+ --dpi-desync-retrans=0|1                       ; 0(default)=reinject original data packet after fake  1=drop original data packet to force its retransmission
  --dpi-desync-repeats=<N>                       ; send every desync packet N times
- --dpi-desync-skip-nosni=0|1		; 1(default)=do not apply desync to requests without hostname in the SNI
+ --dpi-desync-skip-nosni=0|1                    ; 1(default)=do not act on ClientHello without SNI (ESNI ?)
- --dpi-desync-split-pos=<1..1500>	; (for split* and disorder* only) split TCP packet at specified position
+ --dpi-desync-split-pos=<1..9216>               ; data payload split position
  --dpi-desync-ipfrag-pos-tcp=<8..9216>          ; ip frag position starting from the transport header. multiple of 8, default 8.
  --dpi-desync-ipfrag-pos-udp=<8..9216>          ; ip frag position starting from the transport header. multiple of 8, default 32.
  --dpi-desync-badseq-increment=<int|0xHEX>      ; badseq fooling seq signed increment. default -10000
  --dpi-desync-badack-increment=<int|0xHEX>      ; badseq fooling ackseq signed increment. default -66000
  --dpi-desync-any-protocol=0|1                  ; 0(default)=desync only http and tls  1=desync any nonempty data packet
- --dpi-desync-fake-http=<filename>      ; file containing fake http request. replacement for built-in
+ --dpi-desync-fake-http=<filename>|0xHEX        ; file containing fake http request
- --dpi-desync-fake-tls=<filename>       ; file containing fake TLS ClientHello (for https). replacement for built-in
+ --dpi-desync-fake-tls=<filename>|0xHEX         ; file containing fake TLS ClientHello (for https)
- --dpi-desync-fake-unknown=<filename>   ; file containing unknown protocol fake payload. default is 256 zeroes
+ --dpi-desync-fake-unknown=<filename>|0xHEX     ; file containing unknown protocol fake payload
- --dpi-desync-fake-quic=<filename>      ; file containing fake QUIC Initial
+ --dpi-desync-fake-quic=<filename>|0xHEX        ; file containing fake QUIC Initial
- --dpi-desync-fake-unknown-udp=<filename> ; file containing unknown udp protocol fake payload
+ --dpi-desync-fake-wireguard=<filename>|0xHEX   ; file containing fake wireguard handshake initiation
+ --dpi-desync-fake-unknown-udp=<filename>|0xHEX ; file containing unknown udp protocol fake payload
+ --dpi-desync-udplen-increment=<int>            ; increase or decrease udp packet length by N bytes (default 2). negative values decrease length.
+ --dpi-desync-udplen-pattern=<filename>|0xHEX   ; udp tail fill pattern
  --dpi-desync-cutoff=[n|d|s]N                   ; apply dpi desync only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N
- --hostlist=<filename>                  ; only act on hosts in the list (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)
+ --hostlist=<filename>                          ; apply dpi desync only to the listed hosts (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)
- --hostlist-exclude=<filename>          ; do not act on hosts in the list (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)
+ --hostlist-exclude=<filename>                  ; do not apply dpi desync to the listed hosts (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)
 ```
 
 The manipulation parameters can be combined in any way.

docs/readme.txt

@@ -219,12 +219,13 @@ nfqws
  --dpi-desync-badseq-increment=<int|0xHEX>      ; инкремент sequence number для badseq. по умолчанию -10000
  --dpi-desync-badack-increment=<int|0xHEX>      ; инкремент ack sequence number для badseq. по умолчанию -66000
  --dpi-desync-any-protocol=0|1                  ; 0(default)=работать только по http request и tls clienthello  1=по всем непустым пакетам данных
- --dpi-desync-fake-http=<filename>	; файл, содержащий фейковый http запрос для dpi-desync=fake, на замену стандартному w3.org
+ --dpi-desync-fake-http=<filename>|0xHEX	; файл, содержащий фейковый http запрос для dpi-desync=fake, на замену стандартному w3.org
- --dpi-desync-fake-tls=<filename>	; файл, содержащий фейковый tls clienthello для dpi-desync=fake, на замену стандартному w3.org
+ --dpi-desync-fake-tls=<filename>|0xHEX	        ; файл, содержащий фейковый tls clienthello для dpi-desync=fake, на замену стандартному w3.org
- --dpi-desync-fake-unknown=<filename>	; файл, содержащий фейковый пейлоад неизвестного протокола для dpi-desync=fake, на замену стандартным нулям 256 байт
+ --dpi-desync-fake-unknown=<filename>|0xHEX	; файл, содержащий фейковый пейлоад неизвестного протокола для dpi-desync=fake, на замену стандартным нулям 256 байт
- --dpi-desync-fake-quic=<filename>      ; файл, содержащий фейковый QUIC Initial
+ --dpi-desync-fake-quic=<filename>|0xHEX        ; файл, содержащий фейковый QUIC Initial
- --dpi-desync-fake-unknown-udp=<filename> ; файл, содержащий фейковый пейлоад неизвестного udp протокола для dpi-desync=fake, на замену стандартным нулям 64 байт
+ --dpi-desync-fake-unknown-udp=<filename>|0xHEX ; файл, содержащий фейковый пейлоад неизвестного udp протокола для dpi-desync=fake, на замену стандартным нулям 64 байт
  --dpi-desync-udplen-increment=<int>            ; насколько увеличивать длину udp пейлоада в режиме udplen
+ --dpi-desync-udplen-pattern=<filename>|0xHEX   ; чем добивать udp пакет в режиме udplen. по умолчанию - нули
  --dpi-desync-cutoff=[n|d|s]N                   ; применять dpi desync только в исходящих пакетах (n), пакетах данных (d), относительных sequence (s) по номеру меньше N
  --hostlist=<filename>			        ; применять дурение только к хостам из листа. может быть множество листов, они обьединяются. пустой обший лист = его отсутствие
  --hostlist-exclude=<filename>		        ; не применять дурение к хостам из листа. может быть множество листов, они обьединяются

nfq/darkmagic.c

@@ -299,6 +299,7 @@ bool prepare_udp_segment4(
 	const struct sockaddr_in *src, const struct sockaddr_in *dst,
 	uint8_t ttl,
 	uint8_t fooling,
+	const uint8_t *padding, size_t padding_size,
 	int padlen,
 	const void *data, uint16_t len,
 	uint8_t *buf, size_t *buflen)
@@ -324,6 +325,9 @@ bool prepare_udp_segment4(
 	fill_udphdr(udp, src->sin_port, dst->sin_port, datalen);
 
 	memcpy(payload,data,len);
+	if (padding)
+		fill_pattern(payload+len,padlen,padding,padding_size);
+	else
 		memset(payload+len,0,padlen);
 	udp4_fix_checksum(udp,ip_payload_len,&ip->ip_src,&ip->ip_dst);
 	if (fooling & FOOL_BADSUM) udp->uh_sum^=htons(0xBEAF);
@@ -335,6 +339,7 @@ bool prepare_udp_segment6(
 	const struct sockaddr_in6 *src, const struct sockaddr_in6 *dst,
 	uint8_t ttl,
 	uint8_t fooling,
+	const uint8_t *padding, size_t padding_size,
 	int padlen,
 	const void *data, uint16_t len,
 	uint8_t *buf, size_t *buflen)
@@ -408,6 +413,9 @@ bool prepare_udp_segment6(
 	fill_udphdr(udp, src->sin6_port, dst->sin6_port, datalen);
 
 	memcpy(payload,data,len);
+	if (padding)
+		fill_pattern(payload+len,padlen,padding,padding_size);
+	else
 		memset(payload+len,0,padlen);
 	udp6_fix_checksum(udp,transport_payload_len,&ip6->ip6_src,&ip6->ip6_dst);
 	if (fooling & FOOL_BADSUM) udp->uh_sum^=htons(0xBEAF);
@@ -419,14 +427,15 @@ bool prepare_udp_segment(
 	const struct sockaddr *src, const struct sockaddr *dst,
 	uint8_t ttl,
 	uint8_t fooling,
+	const uint8_t *padding, size_t padding_size,
 	int padlen,
 	const void *data, uint16_t len,
 	uint8_t *buf, size_t *buflen)
 {
 	return (src->sa_family==AF_INET && dst->sa_family==AF_INET) ?
-		prepare_udp_segment4((struct sockaddr_in *)src,(struct sockaddr_in *)dst,ttl,fooling,padlen,data,len,buf,buflen) :
+		prepare_udp_segment4((struct sockaddr_in *)src,(struct sockaddr_in *)dst,ttl,fooling,padding,padding_size,padlen,data,len,buf,buflen) :
 		(src->sa_family==AF_INET6 && dst->sa_family==AF_INET6) ?
-		prepare_udp_segment6((struct sockaddr_in6 *)src,(struct sockaddr_in6 *)dst,ttl,fooling,padlen,data,len,buf,buflen) :
+		prepare_udp_segment6((struct sockaddr_in6 *)src,(struct sockaddr_in6 *)dst,ttl,fooling,padding,padding_size,padlen,data,len,buf,buflen) :
 		false;
 }
 

nfq/darkmagic.h

@@ -73,6 +73,7 @@ bool prepare_udp_segment4(
 	const struct sockaddr_in *src, const struct sockaddr_in *dst,
 	uint8_t ttl,
 	uint8_t fooling,
+	const uint8_t *padding, size_t padding_size,
 	int padlen,
 	const void *data, uint16_t len,
 	uint8_t *buf, size_t *buflen);
@@ -80,6 +81,7 @@ bool prepare_udp_segment6(
 	const struct sockaddr_in6 *src, const struct sockaddr_in6 *dst,
 	uint8_t ttl,
 	uint8_t fooling,
+	const uint8_t *padding, size_t padding_size,
 	int padlen,
 	const void *data, uint16_t len,
 	uint8_t *buf, size_t *buflen);
@@ -87,6 +89,7 @@ bool prepare_udp_segment(
 	const struct sockaddr *src, const struct sockaddr *dst,
 	uint8_t ttl,
 	uint8_t fooling,
+	const uint8_t *padding, size_t padding_size,
 	int padlen,
 	const void *data, uint16_t len,
 	uint8_t *buf, size_t *buflen);

nfq/desync.c

@@ -783,7 +783,7 @@ packet_process_result dpi_desync_udp_packet(uint32_t fwmark, const char *ifout,
 					break;
 				}
 			case DESYNC_FAKE:
-				if (!prepare_udp_segment((struct sockaddr *)&src, (struct sockaddr *)&dst, ttl_fake, params.desync_fooling_mode, 0, fake, fake_size, pkt1, &pkt1_len))
+				if (!prepare_udp_segment((struct sockaddr *)&src, (struct sockaddr *)&dst, ttl_fake, params.desync_fooling_mode, NULL, 0, 0, fake, fake_size, pkt1, &pkt1_len))
 					return res;
 				DLOG("sending fake request : ");
 				hexdump_limited_dlog(fake,fake_size,PKTDATA_MAXDUMP); DLOG("\n")
@@ -798,7 +798,7 @@ packet_process_result dpi_desync_udp_packet(uint32_t fwmark, const char *ifout,
 				if (ip6hdr && (params.desync_mode2==DESYNC_NONE || !desync_valid_second_stage_udp(params.desync_mode2)))
 				{
 					if (!prepare_udp_segment((struct sockaddr *)&src, (struct sockaddr *)&dst,
-						ttl_orig,fooling_orig,0,
+						ttl_orig,fooling_orig,NULL,0,0,
 						data_payload, len_payload, pkt1, &pkt1_len))
 					{
 						return res;
@@ -837,7 +837,7 @@ packet_process_result dpi_desync_udp_packet(uint32_t fwmark, const char *ifout,
 		{
 			case DESYNC_UDPLEN:
 				pkt1_len = sizeof(pkt1);
-				if (!prepare_udp_segment((struct sockaddr *)&src, (struct sockaddr *)&dst, ttl_orig,fooling_orig, params.udplen_increment, data_payload, len_payload, pkt1, &pkt1_len))
+				if (!prepare_udp_segment((struct sockaddr *)&src, (struct sockaddr *)&dst, ttl_orig,fooling_orig, params.udplen_pattern, sizeof(params.udplen_pattern), params.udplen_increment, data_payload, len_payload, pkt1, &pkt1_len))
 				{
 					DLOG("could not construct packet with modified length. too large ?\n");
 					return res;

nfq/helpers.c

@@ -179,3 +179,50 @@ void phton64(uint8_t *p, uint64_t v)
 	p[6] = (uint8_t)(v >> 8);
 	p[7] = (uint8_t)(v >> 0);
 }
+
+#define INVALID_HEX_DIGIT ((uint8_t)-1)
+static inline uint8_t parse_hex_digit(char c)
+{
+	return (c>='0' && c<='9') ? c-'0' : (c>='a' && c<='f') ? c-'a'+0xA : (c>='A' && c<='F') ? c-'A'+0xA : INVALID_HEX_DIGIT;
+}
+static inline bool parse_hex_byte(const char *s, uint8_t *pbyte)
+{
+	uint8_t u,l;
+	u = parse_hex_digit(s[0]);
+	l = parse_hex_digit(s[1]);
+	if (u==INVALID_HEX_DIGIT || l==INVALID_HEX_DIGIT)
+	{
+		*pbyte=0;
+		return false;
+	}
+	else
+	{
+		*pbyte=(u<<4) | l;
+		return true;
+	}
+}
+bool parse_hex_str(const char *s, uint8_t *pbuf, size_t *size)
+{
+	uint8_t *pe = pbuf+*size;
+	*size=0;
+	while(pbuf<pe && *s)
+	{
+		if (!parse_hex_byte(s,pbuf))
+			return false;
+		pbuf++; s+=2; (*size)++;
+	}
+	return true;
+}
+
+void fill_pattern(uint8_t *buf,size_t bufsize,const void *pattern,size_t patsize)
+{
+	size_t size;
+
+	while (bufsize)
+	{
+		size = bufsize>patsize ? patsize : bufsize;
+		memcpy(buf,pattern,size);
+		buf += size;
+		bufsize -= size;
+	}
+}

nfq/helpers.h

@@ -34,3 +34,6 @@ static inline void phton16(uint8_t *p, uint16_t v) {
 static inline uint32_t pntoh32(const uint8_t *p) {
 	return ((uint32_t)p[0] << 24) | ((uint32_t)p[1] << 16) | ((uint32_t)p[2] << 8) | (uint32_t)p[3];
 }
+
+bool parse_hex_str(const char *s, uint8_t *pbuf, size_t *size);
+void fill_pattern(uint8_t *buf,size_t bufsize,const void *pattern,size_t patsize);

nfq/nfqws.c

@@ -504,54 +504,55 @@ static void exithelp()
 #ifdef __linux__
 		" --qnum=<nfqueue_number>\n"
 #elif defined(BSD)
-		" --port=<port>\t\t\t\t; divert port\n"
+		" --port=<port>\t\t\t\t\t; divert port\n"
 #endif
-		" --daemon\t\t\t\t; daemonize\n"
+		" --daemon\t\t\t\t\t; daemonize\n"
-		" --pidfile=<filename>\t\t\t; write pid to file\n"
+		" --pidfile=<filename>\t\t\t\t; write pid to file\n"
-		" --user=<username>\t\t\t; drop root privs\n"
+		" --user=<username>\t\t\t\t; drop root privs\n"
-		" --uid=uid[:gid]\t\t\t; drop root privs\n"
+		" --uid=uid[:gid]\t\t\t\t; drop root privs\n"
 #ifdef __linux__
-		" --bind-fix4\t\t\t\t; apply outgoing interface selection fix for generated ipv4 packets\n"
+		" --bind-fix4\t\t\t\t\t; apply outgoing interface selection fix for generated ipv4 packets\n"
-		" --bind-fix6\t\t\t\t; apply outgoing interface selection fix for generated ipv6 packets\n"
+		" --bind-fix6\t\t\t\t\t; apply outgoing interface selection fix for generated ipv6 packets\n"
 #endif
-		" --wsize=<window_size>[:<scale_factor>]\t; set window size. 0 = do not modify. OBSOLETE !\n"
+		" --wsize=<window_size>[:<scale_factor>]\t\t; set window size. 0 = do not modify. OBSOLETE !\n"
-		" --wssize=<window_size>[:<scale_factor>]; set window size for server. 0 = do not modify. default scale_factor = 0.\n"
+		" --wssize=<window_size>[:<scale_factor>]\t; set window size for server. 0 = do not modify. default scale_factor = 0.\n"
-		" --wssize-cutoff=[n|d|s]N\t\t; apply server wsize only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N\n"
+		" --wssize-cutoff=[n|d|s]N\t\t\t; apply server wsize only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N\n"
-		" --ctrack-timeouts=S:E:F[:U]\t\t; internal conntrack timeouts for TCP SYN, ESTABLISHED, FIN stages, UDP timeout. default %u:%u:%u:%u\n"
+		" --ctrack-timeouts=S:E:F[:U]\t\t\t; internal conntrack timeouts for TCP SYN, ESTABLISHED, FIN stages, UDP timeout. default %u:%u:%u:%u\n"
-		" --hostcase\t\t\t\t; change Host: => host:\n"
+		" --hostcase\t\t\t\t\t; change Host: => host:\n"
-		" --hostspell\t\t\t\t; exact spelling of \"Host\" header. must be 4 chars. default is \"host\"\n"
+		" --hostspell\t\t\t\t\t; exact spelling of \"Host\" header. must be 4 chars. default is \"host\"\n"
-		" --hostnospace\t\t\t\t; remove space after Host: and add it to User-Agent: to preserve packet size\n"
+		" --hostnospace\t\t\t\t\t; remove space after Host: and add it to User-Agent: to preserve packet size\n"
-		" --domcase\t\t\t\t; mix domain case : Host: TeSt.cOm\n"
+		" --domcase\t\t\t\t\t; mix domain case : Host: TeSt.cOm\n"
-		" --dpi-desync=[<mode0>,]<mode>[,<mode2>] ; try to desync dpi state. modes : synack fake fakeknown rst rstack hopbyhop destopt ipfrag1 disorder disorder2 split split2 ipfrag2 udplen\n"
+		" --dpi-desync=[<mode0>,]<mode>[,<mode2>]\t; try to desync dpi state. modes : synack fake fakeknown rst rstack hopbyhop destopt ipfrag1 disorder disorder2 split split2 ipfrag2 udplen\n"
 #ifdef __linux__
-		" --dpi-desync-fwmark=<int|0xHEX>\t; override fwmark for desync packet. default = 0x%08X (%u)\n"
+		" --dpi-desync-fwmark=<int|0xHEX>\t\t; override fwmark for desync packet. default = 0x%08X (%u)\n"
 #elif defined(SO_USER_COOKIE)
-		" --dpi-desync-sockarg=<int|0xHEX>\t; override sockarg (SO_USER_COOKIE) for desync packet. default = 0x%08X (%u)\n"
+		" --dpi-desync-sockarg=<int|0xHEX>\t\t; override sockarg (SO_USER_COOKIE) for desync packet. default = 0x%08X (%u)\n"
 #endif
-		" --dpi-desync-ttl=<int>\t\t\t; set ttl for desync packet\n"
+		" --dpi-desync-ttl=<int>\t\t\t\t; set ttl for desync packet\n"
-		" --dpi-desync-ttl6=<int>\t\t; set ipv6 hop limit for desync packet. by default ttl value is used.\n"
+		" --dpi-desync-ttl6=<int>\t\t\t; set ipv6 hop limit for desync packet. by default ttl value is used.\n"
-		" --dpi-desync-fooling=<mode>[,<mode>]\t; can use multiple comma separated values. modes : none md5sig ts badseq badsum hopbyhop hopbyhop2\n"
+		" --dpi-desync-fooling=<mode>[,<mode>]\t\t; can use multiple comma separated values. modes : none md5sig ts badseq badsum hopbyhop hopbyhop2\n"
 #ifdef __linux__
-		" --dpi-desync-retrans=0|1\t\t; 0(default)=reinject original data packet after fake  1=drop original data packet to force its retransmission\n"
+		" --dpi-desync-retrans=0|1\t\t\t; 0(default)=reinject original data packet after fake  1=drop original data packet to force its retransmission\n"
 #endif
-		" --dpi-desync-repeats=<N>\t\t; send every desync packet N times\n"
+		" --dpi-desync-repeats=<N>\t\t\t; send every desync packet N times\n"
-		" --dpi-desync-skip-nosni=0|1\t\t; 1(default)=do not act on ClientHello without SNI (ESNI ?)\n"
+		" --dpi-desync-skip-nosni=0|1\t\t\t; 1(default)=do not act on ClientHello without SNI (ESNI ?)\n"
-		" --dpi-desync-split-pos=<1..%u>\t; data payload split position\n"
+		" --dpi-desync-split-pos=<1..%u>\t\t; data payload split position\n"
-		" --dpi-desync-ipfrag-pos-tcp=<8..%u>\t; ip frag position starting from the transport header. multiple of 8, default %u.\n"
+		" --dpi-desync-ipfrag-pos-tcp=<8..%u>\t\t; ip frag position starting from the transport header. multiple of 8, default %u.\n"
-		" --dpi-desync-ipfrag-pos-udp=<8..%u>\t; ip frag position starting from the transport header. multiple of 8, default %u.\n"
+		" --dpi-desync-ipfrag-pos-udp=<8..%u>\t\t; ip frag position starting from the transport header. multiple of 8, default %u.\n"
-		" --dpi-desync-badseq-increment=<int|0xHEX> ; badseq fooling seq signed increment. default %d\n"
+		" --dpi-desync-badseq-increment=<int|0xHEX>\t; badseq fooling seq signed increment. default %d\n"
-		" --dpi-desync-badack-increment=<int|0xHEX> ; badseq fooling ackseq signed increment. default %d\n"
+		" --dpi-desync-badack-increment=<int|0xHEX>\t; badseq fooling ackseq signed increment. default %d\n"
-		" --dpi-desync-any-protocol=0|1\t\t; 0(default)=desync only http and tls  1=desync any nonempty data packet\n"
+		" --dpi-desync-any-protocol=0|1\t\t\t; 0(default)=desync only http and tls  1=desync any nonempty data packet\n"
-		" --dpi-desync-fake-http=<filename>\t; file containing fake http request\n"
+		" --dpi-desync-fake-http=<filename>|0xHEX\t; file containing fake http request\n"
-		" --dpi-desync-fake-tls=<filename>\t; file containing fake TLS ClientHello (for https)\n"
+		" --dpi-desync-fake-tls=<filename>|0xHEX\t\t; file containing fake TLS ClientHello (for https)\n"
-		" --dpi-desync-fake-unknown=<filename>\t; file containing unknown protocol fake payload\n"
+		" --dpi-desync-fake-unknown=<filename>|0xHEX\t; file containing unknown protocol fake payload\n"
-		" --dpi-desync-fake-quic=<filename>\t; file containing fake QUIC Initial\n"
+		" --dpi-desync-fake-quic=<filename>|0xHEX\t; file containing fake QUIC Initial\n"
-		" --dpi-desync-fake-wireguard=<filename>\t; file containing fake wireguard handshake initiation\n"
+		" --dpi-desync-fake-wireguard=<filename>|0xHEX\t; file containing fake wireguard handshake initiation\n"
-		" --dpi-desync-fake-unknown-udp=<filename> ; file containing unknown udp protocol fake payload\n"
+		" --dpi-desync-fake-unknown-udp=<filename>|0xHEX\t; file containing unknown udp protocol fake payload\n"
-		" --dpi-desync-udplen-increment=<int>\t; increase or decrease udp packet length by N bytes (default %u). negative values decrease length.\n"
+		" --dpi-desync-udplen-increment=<int>\t\t; increase or decrease udp packet length by N bytes (default %u). negative values decrease length.\n"
-		" --dpi-desync-cutoff=[n|d|s]N\t\t; apply dpi desync only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N\n"
+		" --dpi-desync-udplen-pattern=<filename>|0xHEX\t; udp tail fill pattern\n"
-		" --hostlist=<filename>\t\t\t; apply dpi desync only to the listed hosts (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)\n"
+		" --dpi-desync-cutoff=[n|d|s]N\t\t\t; apply dpi desync only to packet numbers (n, default), data packet numbers (d), relative sequence (s) less than N\n"
-		" --hostlist-exclude=<filename>\t\t; do not apply dpi desync to the listed hosts (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)\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"
+		" --hostlist-exclude=<filename>\t\t\t; do not apply dpi desync to the listed hosts (one host per line, subdomains auto apply, gzip supported, multiple hostlists allowed)\n",
 		CTRACK_T_SYN, CTRACK_T_EST, CTRACK_T_FIN, CTRACK_T_UDP,
 #if defined(__linux__) || defined(SO_USER_COOKIE)
 		DPI_DESYNC_FWMARK_DEFAULT,DPI_DESYNC_FWMARK_DEFAULT,
@@ -611,6 +612,17 @@ static bool parse_badseq_increment(const char *opt, uint32_t *value)
 	}
 }
 static void load_file_or_exit(const char *filename, void *buf, size_t *size)
+{
+	if (filename[0]=='0' && filename[1]=='x')
+	{
+		if (!parse_hex_str(filename+2,buf,size) || !*size)
+		{
+			fprintf(stderr, "invalid hex string: %s\n",filename+2);
+			exit_clean(1);
+		}
+		DLOG("read %zu bytes from hex string\n",*size)
+	}
+	else
 	{
 		if (!load_file_nonempty(filename,buf,size))
 		{
@@ -619,6 +631,7 @@ static void load_file_or_exit(const char *filename, void *buf, size_t *size)
 		}
 		DLOG("read %zu bytes from %s\n",*size,filename)
 	}
+}
 
 
 int main(int argc, char **argv)
@@ -717,12 +730,13 @@ int main(int argc, char **argv)
 		{"dpi-desync-fake-wireguard",required_argument,0,0},// optidx=32
 		{"dpi-desync-fake-unknown-udp",required_argument,0,0},// optidx=33
 		{"dpi-desync-udplen-increment",required_argument,0,0},// optidx=34
-		{"dpi-desync-cutoff",required_argument,0,0},// optidx=35
+		{"dpi-desync-udplen-pattern",required_argument,0,0},// optidx=35
-		{"hostlist",required_argument,0,0},		// optidx=36
+		{"dpi-desync-cutoff",required_argument,0,0},// optidx=36
-		{"hostlist-exclude",required_argument,0,0},	// optidx=37
+		{"hostlist",required_argument,0,0},		// optidx=37
+		{"hostlist-exclude",required_argument,0,0},	// optidx=38
 #ifdef __linux__
-		{"bind-fix4",no_argument,0,0},		// optidx=38
+		{"bind-fix4",no_argument,0,0},		// optidx=39
-		{"bind-fix6",no_argument,0,0},		// optidx=39
+		{"bind-fix6",no_argument,0,0},		// optidx=40
 #endif
 		{NULL,0,NULL,0}
 	};
@@ -1019,21 +1033,29 @@ int main(int argc, char **argv)
 				exit_clean(1);
 			}
 			break;
-		case 35: /* desync-cutoff */
+		case 35: /* dpi-desync-udplen-pattern */
+			{
+				char buf[sizeof(params.udplen_pattern)];
+				size_t sz=sizeof(buf);
+				load_file_or_exit(optarg,buf,&sz);
+				fill_pattern(params.udplen_pattern,sizeof(params.udplen_pattern),buf,sz);
+			}
+			break;
+		case 36: /* desync-cutoff */
 			if (!parse_cutoff(optarg, &params.desync_cutoff, &params.desync_cutoff_mode))
 			{
 				fprintf(stderr, "invalid desync-cutoff value\n");
 				exit_clean(1);
 			}
 			break;
-		case 36: /* hostlist */
+		case 37: /* hostlist */
 			if (!strlist_add(&params.hostlist_files, optarg))
 			{
 				fprintf(stderr, "strlist_add failed\n");
 				exit_clean(1);
 			}
 			break;
-		case 37: /* hostlist-exclude */
+		case 38: /* hostlist-exclude */
 			if (!strlist_add(&params.hostlist_exclude_files, optarg))
 			{
 				fprintf(stderr, "strlist_add failed\n");
@@ -1041,10 +1063,10 @@ int main(int argc, char **argv)
 			}
 			break;
 #ifdef __linux__
-		case 38: /* bind-fix4 */
+		case 39: /* bind-fix4 */
 			params.bind_fix4 = true;
 			break;
-		case 39: /* bind-fix6 */
+		case 40: /* bind-fix6 */
 			params.bind_fix6 = true;
 			break;
 #endif

nfq/params.h

@@ -50,7 +50,7 @@ struct params_s
 	uint8_t desync_fooling_mode;
 	uint32_t desync_fwmark; // unused in BSD
 	uint32_t desync_badseq_increment, desync_badseq_ack_increment;
-	uint8_t fake_http[1432],fake_tls[1432],fake_quic[1472],fake_wg[1472],fake_unknown[1432],fake_unknown_udp[1472];
+	uint8_t fake_http[1432],fake_tls[1432],fake_quic[1472],fake_wg[1472],fake_unknown[1432],fake_unknown_udp[1472], udplen_pattern[1472];
 	size_t fake_http_size,fake_tls_size,fake_quic_size,fake_wg_size,fake_unknown_size,fake_unknown_udp_size;
 	int udplen_increment;
 	bool droproot;