update config.default

config.default

@@ -55,7 +55,7 @@ TPPORT_SOCKS=987
 # <HOSTLIST_NOAUTO> appends ipset/zapret-hosts-auto.txt as normal list
 TPWS_SOCKS_OPT="
 --filter-tcp=80 --methodeol <HOSTLIST> --new
---filter-tcp=443 --split-tls=sni --disorder <HOSTLIST>
+--filter-tcp=443 --split-pos=midsld --disorder <HOSTLIST>
 "
 
 TPWS_ENABLE=0
@@ -65,7 +65,7 @@ TPWS_PORTS=80,443
 # <HOSTLIST_NOAUTO> appends ipset/zapret-hosts-auto.txt as normal list
 TPWS_OPT="
 --filter-tcp=80 --methodeol <HOSTLIST> --new
---filter-tcp=443 --split-tls=sni --disorder <HOSTLIST>
+--filter-tcp=443 --split-pos=midsld --disorder <HOSTLIST>
 "
 
 NFQWS_ENABLE=0
@@ -89,8 +89,8 @@ NFQWS_UDP_PKT_IN=0
 # hostlist markers are replaced to empty string if MODE_FILTER does not satisfy
 # <HOSTLIST_NOAUTO> appends ipset/zapret-hosts-auto.txt as normal list
 NFQWS_OPT="
---filter-tcp=80 --dpi-desync=fake,split2 --dpi-desync-fooling=md5sig <HOSTLIST> --new
+--filter-tcp=80 --dpi-desync=fake,multisplit --dpi-desync-split-pos=method+2 --dpi-desync-fooling=md5sig <HOSTLIST> --new
---filter-tcp=443 --dpi-desync=fake,disorder2 --dpi-desync-fooling=md5sig <HOSTLIST> --new
+--filter-tcp=443 --dpi-desync=fake,multidisorder --dpi-desync-split-pos=midsld --dpi-desync-fooling=md5sig <HOSTLIST> --new
 --filter-udp=443 --dpi-desync=fake --dpi-desync-repeats=6 <HOSTLIST_NOAUTO>
 "
 

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 -Lwindows/windivert -Iwindows -lwlanapi -lole32 -loleaut32 -luuid
+LIBS_CYGWIN = -lz -Lwindows/windivert -Iwindows -lwlanapi -lole32 -loleaut32
 LIBS_CYGWIN32 = -lwindivert32
 LIBS_CYGWIN64 = -lwindivert64
 RES_CYGWIN32 = windows/res/32/winmanifest.o windows/res/32/winicon.o

nfq/darkmagic.h

@@ -22,6 +22,7 @@
 #endif
 
 #ifdef __CYGWIN__
+#define INITGUID
 #include "windivert/windivert.h"
 #endif
 

tpws/helpers.c

@@ -1,8 +1,8 @@
 #define _GNU_SOURCE
 
-#include "helpers.h"
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 #include <ctype.h>
 #include <errno.h>
 #include <sys/socket.h>
@@ -11,6 +11,29 @@
 #include <time.h>
 #include <sys/stat.h>
 
+#include "helpers.h"
+
+int unique_size_t(size_t *pu, int ct)
+{
+	int i, j, u;
+	for (i = j = 0; j < ct; i++)
+	{
+		u = pu[j++];
+		for (; j < ct && pu[j] == u; j++);
+		pu[i] = u;
+	}
+	return i;
+}
+static int cmp_size_t(const void * a, const void * b)
+{
+	return *(size_t*)a < *(size_t*)b ? -1 : *(size_t*)a > *(size_t*)b;
+}
+void qsort_size_t(size_t *array,size_t ct)
+{
+	qsort(array,ct,sizeof(*array),cmp_size_t);
+}
+
+
 void rtrim(char *s)
 {
 	if (s)

tpws/helpers.h

@@ -15,6 +15,9 @@ typedef union
 	struct sockaddr_in6 sa6;	// size 28
 } sockaddr_in46;
 
+int unique_size_t(size_t *pu, int ct);
+void qsort_size_t(size_t *array,size_t ct);
+
 void rtrim(char *s);
 void replace_char(char *s, char from, char to);
 char *strncasestr(const char *s,const char *find, size_t slen);

tpws/params.c

@@ -139,6 +139,22 @@ int HOSTLIST_DEBUGLOG_APPEND(const char *format, ...)
 		return 0;
 }
 
+void hexdump_limited_dlog(const uint8_t *data, size_t size, size_t limit)
+{
+	size_t k;
+	bool bcut = false;
+	if (size > limit)
+	{
+		size = limit;
+		bcut = true;
+	}
+	if (!size) return;
+	for (k = 0; k < size; k++) VPRINT("%02X ", data[k]);
+	VPRINT(bcut ? "... : " : ": ");
+	for (k = 0; k < size; k++) VPRINT("%c", data[k] >= 0x20 && data[k] <= 0x7F ? (char)data[k] : '.');
+	if (bcut) VPRINT(" ...");
+}
+
 
 struct desync_profile_list *dp_list_add(struct desync_profile_list_head *head)
 {

tpws/params.h

@@ -29,6 +29,8 @@ struct bind_s
 	int bind_wait_ifup,bind_wait_ip,bind_wait_ip_ll;
 };
 
+#define MAX_SPLITS	16
+
 enum log_target { LOG_TARGET_CONSOLE=0, LOG_TARGET_FILE, LOG_TARGET_SYSLOG };
 
 struct desync_profile
@@ -38,16 +40,16 @@ struct desync_profile
 	bool hostcase, hostdot, hosttab, hostnospace, methodspace, methodeol, unixeol, domcase;
 	int hostpad;
 	char hostspell[4];
-	enum httpreqpos split_http_req;
-	enum tlspos tlsrec;
-	int tlsrec_pos;
-	enum tlspos split_tls;
 	bool split_any_protocol;
-	int split_pos;
 	bool disorder, disorder_http, disorder_tls;
 	bool oob, oob_http, oob_tls;
 	uint8_t oob_byte;
 
+	// multisplit
+	struct proto_pos splits[MAX_SPLITS];
+	int split_count;
+	struct proto_pos tlsrec;
+
 	int mss;
 
 	bool tamper_start_n,tamper_cutoff_n;
@@ -140,6 +142,7 @@ int DLOG_CONDUP(const char *format, ...);
 int DLOG_ERR(const char *format, ...);
 int DLOG_PERROR(const char *s);
 int HOSTLIST_DEBUGLOG_APPEND(const char *format, ...);
+void hexdump_limited_dlog(const uint8_t *data, size_t size, size_t limit);
 
 #define VPRINT(format, ...) DLOG(format, 1, ##__VA_ARGS__)
 #define DBGPRINT(format, ...) DLOG(format, 2, ##__VA_ARGS__)

tpws/protocol.c

@@ -24,6 +24,133 @@ static bool FindNLD(const uint8_t *dom, size_t dlen, int level, const uint8_t **
 	return true;
 }
 
+const char *l7proto_str(t_l7proto l7)
+{
+	switch(l7)
+	{
+		case HTTP: return "http";
+		case TLS: return "tls";
+		case QUIC: return "quic";
+		case WIREGUARD: return "wireguard";
+		case DHT: return "dht";
+		default: return "unknown";
+	}
+}
+bool l7_proto_match(t_l7proto l7proto, uint32_t filter_l7)
+{
+	return  (l7proto==UNKNOWN && (filter_l7 & L7_PROTO_UNKNOWN)) ||
+		(l7proto==HTTP && (filter_l7 & L7_PROTO_HTTP)) ||
+		(l7proto==TLS && (filter_l7 & L7_PROTO_TLS)) ||
+		(l7proto==QUIC && (filter_l7 & L7_PROTO_QUIC)) ||
+		(l7proto==WIREGUARD && (filter_l7 & L7_PROTO_WIREGUARD)) ||
+		(l7proto==DHT && (filter_l7 & L7_PROTO_DHT));
+}
+
+#define PM_ABS		0
+#define PM_HOST		1
+#define PM_HOST_END	2
+#define PM_HOST_SLD	3
+#define PM_HOST_MIDSLD	4
+#define PM_HOST_ENDSLD	5
+#define PM_HTTP_METHOD	6
+#define PM_SNI_EXT	7
+bool IsHostMarker(uint8_t posmarker)
+{
+	switch(posmarker)
+	{
+		case PM_HOST:
+		case PM_HOST_END:
+		case PM_HOST_SLD:
+		case PM_HOST_MIDSLD:
+		case PM_HOST_ENDSLD:
+			return true;
+		default:
+			return false;
+	}
+}
+const char *posmarker_name(uint8_t posmarker)
+{
+	switch(posmarker)
+	{
+		case PM_ABS: return "abs";
+		case PM_HOST: return "host";
+		case PM_HOST_END: return "endhost";
+		case PM_HOST_SLD: return "sld";
+		case PM_HOST_MIDSLD: return "midsld";
+		case PM_HOST_ENDSLD: return "endsld";
+		case PM_HTTP_METHOD: return "method";
+		case PM_SNI_EXT: return "sniext";
+		default: return "?";
+	}
+}
+
+static size_t CheckPos(size_t sz, ssize_t offset)
+{
+	return (offset>=0 && offset<sz) ? offset : 0;
+}
+size_t AnyProtoPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz)
+{
+	ssize_t offset;
+	switch(posmarker)
+	{
+		case PM_ABS:
+			offset = (pos<0) ? sz+pos : pos;
+			return CheckPos(sz,offset);
+		default:
+			return 0;
+	}
+}
+static size_t HostPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz, size_t offset_host, size_t len_host)
+{
+	ssize_t offset;
+	const uint8_t *p;
+	size_t slen;
+
+	switch(posmarker)
+	{
+		case PM_HOST:
+			offset = offset_host+pos;
+			break;
+		case PM_HOST_END:
+			offset = offset_host+len_host+pos;
+			break;
+		case PM_HOST_SLD:
+		case PM_HOST_MIDSLD:
+		case PM_HOST_ENDSLD:
+			if (((offset_host+len_host)<=sz) && FindNLD(data+offset_host,len_host,2,&p,&slen))
+				offset = (posmarker==PM_HOST_SLD ? p-data : posmarker==PM_HOST_ENDSLD ? p-data+slen : slen==1 ? p+1-data : p+slen/2-data) + pos;
+			else
+				offset = 0;
+			break;
+	}
+	return CheckPos(sz,offset);
+}
+size_t ResolvePos(const uint8_t *data, size_t sz, t_l7proto l7proto, const struct proto_pos *sp)
+{
+	switch(l7proto)
+	{
+		case HTTP:
+			return HttpPos(sp->marker, sp->pos, data, sz);
+		case TLS:
+			return TLSPos(sp->marker, sp->pos, data, sz);
+		default:
+			return AnyProtoPos(sp->marker, sp->pos, data, sz);
+	}
+}
+void ResolveMultiPos(const uint8_t *data, size_t sz, t_l7proto l7proto, const struct proto_pos *splits, int split_count, size_t *pos, int *pos_count)
+{
+	int i,j;
+	for(i=j=0;i<split_count;i++)
+	{
+		pos[j] = ResolvePos(data,sz,l7proto,splits+i);
+		if (pos[j]) j++;
+	}
+	qsort_size_t(pos, j);
+	j=unique_size_t(pos, j);
+	*pos_count=j;
+}
+
+
 const char *http_methods[] = { "GET /","POST /","HEAD /","OPTIONS /","PUT /","DELETE /","CONNECT /","TRACE /",NULL };
 const char *HttpMethod(const uint8_t *data, size_t len)
 {
@@ -169,36 +296,45 @@ bool HttpReplyLooksLikeDPIRedirect(const uint8_t *data, size_t len, const char *
 	// compare 2nd level domains		
 	return strcasecmp(dhost, drhost)!=0;
 }
-size_t HttpPos(enum httpreqpos tpos_type, size_t hpos_pos, const uint8_t *http, size_t sz)
+size_t HttpPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz)
 {
-	const uint8_t *method, *host=NULL;
+	const uint8_t *method, *host=NULL, *p;
+	size_t offset_host,len_host;
+	ssize_t offset;
 	int i;
 	
-	switch(tpos_type)
+	switch(posmarker)
 	{
-		case httpreqpos_method:
+		case PM_HTTP_METHOD:
 			// recognize some tpws pre-applied hacks
-			method=http;
+			method=data;
 			if (sz<10) break;
 			if (*method=='\n' || *method=='\r') method++;
 			if (*method=='\n' || *method=='\r') method++;
-			for (i=0;i<7;i++) if (*method>='A' && *method<='Z') method++;
+			for (p=method,i=0;i<7;i++) if (*p>='A' && *p<='Z') p++;
-			if (i<3 || *method!=' ') break;
+			if (i<3 || *p!=' ') break;
-			return method-http-1;
+			return CheckPos(sz,method-data+pos);
-		case httpreqpos_host:
+		case PM_HOST:
-			if (HttpFindHostConst(&host,http,sz) && (host-http+7)<sz)
+		case PM_HOST_END:
+		case PM_HOST_SLD:
+		case PM_HOST_MIDSLD:
+		case PM_HOST_ENDSLD:
+			if (HttpFindHostConst(&host,data,sz) && (host-data+7)<sz)
 			{
 				host+=5;
-				if (*host==' ') host++;
+				if (*host==' ' || *host=='\t') host++;
-				return host-http;
+				offset_host = host-data;
+				if (posmarker!=PM_HOST)
+					for (len_host=0; (offset_host+len_host)<sz && data[offset_host+len_host]!='\r' && data[offset_host+len_host]!='\n'; len_host++);
+				else
+					len_host = 0;
+				return HostPos(posmarker,pos,data,sz,offset_host,len_host);
 			}
 			break;
-		case httpreqpos_pos:
-			break;
 		default:
-			return 0;
+			return AnyProtoPos(posmarker,pos,data,sz);
 	}
-	return hpos_pos<sz ? hpos_pos : 0;
+	return 0;
 }
 
 
@@ -361,26 +497,37 @@ static bool TLSHelloFindMiddleOfSLDInSNI(const uint8_t *ext, size_t elen, const
 	*p = (len==1) ? *p+1 : *p+len/2;
 	return true;
 }
-size_t TLSPos(enum tlspos tpos_type, size_t tpos_pos, const uint8_t *tls, size_t sz, uint8_t type)
+size_t TLSPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz)
 {
 	size_t elen;
 	const uint8_t *ext, *p;
-	switch(tpos_type)
+	size_t offset_host,len_host;
+	ssize_t offset;
+
+	switch(posmarker)
 	{
-		case tlspos_sni:
+		case PM_HOST:
-		case tlspos_sniext:
+		case PM_HOST_END:
-			if (TLSFindExt(tls,sz,0,&ext,&elen,false))
+		case PM_HOST_SLD:
-				return (tpos_type==tlspos_sni) ? ext-tls+6 : ext-tls+1;
+		case PM_HOST_MIDSLD:
-			break;
+		case PM_HOST_ENDSLD:
-		case tlspos_snisld:
+		case PM_SNI_EXT:
-			if (TLSFindExt(tls,sz,0,&ext,&elen,false))
+			if (TLSFindExt(data,sz,0,&ext,&elen,false))
-				if (TLSHelloFindMiddleOfSLDInSNI(ext,elen,&p))
+			{
-					return p-tls;
+				if (posmarker==PM_SNI_EXT)
-			break;
+				{
-		case tlspos_pos:
+					return CheckPos(sz,ext-data+pos);
-			break;
+				}
-		default:
+				else
+				{
+					if (!TLSAdvanceToHostInSNI(&ext,&elen,&len_host))
 						return 0;
+					offset_host = ext-data;
+					return HostPos(posmarker,pos,data,sz,offset_host,len_host);
+				}
+			}
+			return 0;
+		default:
+			return AnyProtoPos(posmarker,pos,data,sz);
 	}
-	return tpos_pos<sz ? tpos_pos : 0;
 }

tpws/protocol.h

@@ -4,6 +4,40 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+typedef enum {UNKNOWN=0, HTTP, TLS, QUIC, WIREGUARD, DHT} t_l7proto;
+#define L7_PROTO_HTTP		0x00000001
+#define L7_PROTO_TLS		0x00000002
+#define L7_PROTO_QUIC		0x00000004
+#define L7_PROTO_WIREGUARD	0x00000008
+#define L7_PROTO_DHT		0x00000010
+#define L7_PROTO_UNKNOWN	0x80000000
+const char *l7proto_str(t_l7proto l7);
+bool l7_proto_match(t_l7proto l7proto, uint32_t filter_l7);
+
+// pos markers
+#define PM_ABS		0
+#define PM_HOST		1
+#define PM_HOST_END	2
+#define PM_HOST_SLD	3
+#define PM_HOST_MIDSLD	4
+#define PM_HOST_ENDSLD	5
+#define PM_HTTP_METHOD	6
+#define PM_SNI_EXT	7
+struct proto_pos
+{
+	int16_t pos;
+	uint8_t marker;
+};
+#define PROTO_POS_EMPTY(sp) ((sp)->marker==PM_ABS && (sp)->pos==0)
+bool IsHostMarker(uint8_t posmarker);
+const char *posmarker_name(uint8_t posmarker);
+size_t AnyProtoPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz);
+size_t HttpPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz);
+size_t TLSPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz);
+size_t ResolvePos(const uint8_t *data, size_t sz, t_l7proto l7proto, const struct proto_pos *sp);
+void ResolveMultiPos(const uint8_t *data, size_t sz, t_l7proto l7proto, const struct proto_pos *splits, int split_count, size_t *pos, int *pos_count);
+
+
 extern const char *http_methods[9];
 const char *HttpMethod(const uint8_t *data, size_t len);
 bool IsHttp(const uint8_t *data, size_t len);
@@ -18,8 +52,6 @@ const char *HttpFind2ndLevelDomain(const char *host);
 int HttpReplyCode(const uint8_t *data, size_t len);
 // must be pre-checked by IsHttpReply
 bool HttpReplyLooksLikeDPIRedirect(const uint8_t *data, size_t len, const char *host);
-enum httpreqpos { httpreqpos_none = 0, httpreqpos_method, httpreqpos_host, httpreqpos_pos };
-size_t HttpPos(enum httpreqpos tpos_type, size_t hpos_pos, const uint8_t *http, size_t sz);
 
 uint16_t TLSRecordDataLen(const uint8_t *data);
 size_t TLSRecordLen(const uint8_t *data);
@@ -29,5 +61,3 @@ bool TLSFindExt(const uint8_t *data, size_t len, uint16_t type, const uint8_t **
 bool TLSFindExtInHandshake(const uint8_t *data, size_t len, uint16_t type, const uint8_t **ext, size_t *len_ext, bool bPartialIsOK);
 bool TLSHelloExtractHost(const uint8_t *data, size_t len, char *host, size_t len_host, bool bPartialIsOK);
 bool TLSHelloExtractHostFromHandshake(const uint8_t *data, size_t len, char *host, size_t len_host, bool bPartialIsOK);
-enum tlspos { tlspos_none = 0, tlspos_sni, tlspos_sniext, tlspos_snisld, tlspos_pos };
-size_t TLSPos(enum tlspos tpos_type, size_t tpos_pos, const uint8_t *tls, size_t sz, uint8_t type);

tpws/resolver.c

@@ -221,7 +221,7 @@ bool resolver_init(int threads, int fd_signal_pipe)
 	if (pthread_attr_init(&attr)) goto ex;
 	// set minimum thread stack size
 
-	if (pthread_attr_setstacksize(&attr,PTHREAD_STACK_MIN>20480 ? PTHREAD_STACK_MIN : 20480))
+	if (pthread_attr_setstacksize(&attr,PTHREAD_STACK_MIN>32768 ? PTHREAD_STACK_MIN : 32768))
 	{
 		pthread_attr_destroy(&attr);
 		goto ex;

tpws/tamper.c

@@ -8,22 +8,6 @@
 #include "protocol.h"
 #include "helpers.h"
 
-const char *l7proto_str(t_l7proto l7)
-{
-	switch(l7)
-	{
-		case HTTP: return "http";
-		case TLS: return "tls";
-		default: return "unknown";
-	}
-}
-static bool l7_proto_match(t_l7proto l7proto, uint32_t filter_l7)
-{
-	return  (l7proto==UNKNOWN && (filter_l7 & L7_PROTO_UNKNOWN)) ||
-		(l7proto==HTTP && (filter_l7 & L7_PROTO_HTTP)) ||
-		(l7proto==TLS && (filter_l7 & L7_PROTO_TLS));
-}
-
 static bool dp_match(struct desync_profile *dp, const struct sockaddr *dest, const char *hostname, t_l7proto l7proto)
 {
 	bool bHostlistsEmpty;
@@ -87,11 +71,10 @@ void apply_desync_profile(t_ctrack *ctrack, const struct sockaddr *dest)
 
 
 // segment buffer has at least 5 extra bytes to extend data block
-void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,size_t segment_buffer_size,size_t *size, size_t *split_pos, uint8_t *split_flags)
+void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,size_t segment_buffer_size,size_t *size, size_t *multisplit_pos, int *multisplit_count, uint8_t *split_flags)
 {
 	uint8_t *p, *pp, *pHost = NULL;
-	size_t method_len = 0, pos;
+	size_t method_len = 0, pos, tpos, orig_size=*size;
-	size_t tpos, spos;
 	const char *method;
 	bool bHaveHost = false;
 	char *pc, Host[256];
@@ -116,8 +99,8 @@ void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,
 		return;
 	}
 
-	*split_pos=0;
+	if (multisplit_count) *multisplit_count=0;
-	*split_flags=0;
+	if (split_flags) *split_flags=0;
 
 	if ((method = HttpMethod(segment,*size)))
 	{
@@ -193,7 +176,6 @@ void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,
 			return;
 		}
 	}
-
 	switch(l7proto)
 	{
 		case HTTP:
@@ -325,22 +307,26 @@ void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,
 					pHost = NULL; // invalidate
 				}
 			}
-			*split_pos = HttpPos(ctrack->dp->split_http_req, ctrack->dp->split_pos, segment, *size);
+			if (multisplit_pos) ResolveMultiPos(segment, *size, l7proto, ctrack->dp->splits, ctrack->dp->split_count, multisplit_pos, multisplit_count);
+			if (split_flags)
+			{
 				if (ctrack->dp->disorder_http) *split_flags |= SPLIT_FLAG_DISORDER;
 				if (ctrack->dp->oob_http) *split_flags |= SPLIT_FLAG_OOB;
+			}
 			break;
 
 		case TLS:
-			spos = TLSPos(ctrack->dp->split_tls, ctrack->dp->split_pos, segment, *size, 0);
+			if (multisplit_pos) ResolveMultiPos(segment, *size, l7proto, ctrack->dp->splits, ctrack->dp->split_count, multisplit_pos, multisplit_count);
 			if ((5+*size)<=segment_buffer_size)
 			{
-				tpos = TLSPos(ctrack->dp->tlsrec, ctrack->dp->tlsrec_pos+5, segment, *size, 0);
+				tpos = ResolvePos(segment, *size, l7proto, &ctrack->dp->tlsrec);
 				if (tpos>5)
 				{
 					// construct 2 TLS records from one
 					uint16_t l = pntoh16(segment+3); // length
 					if (l>=2)
 					{
+						int i;
 						// length is checked in IsTLSClientHello and cannot exceed buffer size
 						if ((tpos-5)>=l) tpos=5+1;
 						VPRINT("making 2 TLS records at pos %zu\n",tpos);
@@ -351,28 +337,41 @@ void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,
 						phton16(segment+tpos+3,l-(tpos-5));
 						phton16(segment+3,tpos-5);
 						*size += 5;
-						// split pos present and it is not before tlsrec split. increase split pos by tlsrec header size (5 bytes)
+						// fix split positions after tlsrec. increase split pos by tlsrec header size (5 bytes)
-						if (spos && spos>=tpos) spos+=5;
+						if (multisplit_pos)
+							for(i=0;i<*multisplit_count;i++)
+								if (multisplit_pos[i]>tpos) multisplit_pos[i]+=5;
 					}
 				}
 			}
-
+			if (split_flags)
-			if (spos && spos < *size)
+			{
-				*split_pos = spos;
-
 				if (ctrack->dp->disorder_tls) *split_flags |= SPLIT_FLAG_DISORDER;
 				if (ctrack->dp->oob_tls) *split_flags |= SPLIT_FLAG_OOB;
-			
+			}
 			break;
 
 		default:
-			if (ctrack->dp->split_any_protocol && ctrack->dp->split_pos < *size)
+			if (multisplit_pos && ctrack->dp->split_any_protocol)
-				*split_pos = ctrack->dp->split_pos;
+				ResolveMultiPos(segment, *size, l7proto, ctrack->dp->splits, ctrack->dp->split_count, multisplit_pos, multisplit_count);
 	}
 
+	if (split_flags)
+	{
 		if (ctrack->dp->disorder) *split_flags |= SPLIT_FLAG_DISORDER;
 		if (ctrack->dp->oob) *split_flags |= SPLIT_FLAG_OOB;
 	}
+	if (orig_size!=*size)
+	{
+		VPRINT("segment size changed: %zu -> %zu\n", orig_size, *size);
+	}
+	if (params.debug && multisplit_count && *multisplit_count)
+	{
+		VPRINT("multisplit pos: ");
+		for (int i=0;i<*multisplit_count;i++) VPRINT("%zu ",multisplit_pos[i]);
+		VPRINT("\n");
+	}
+}
 
 static void auto_hostlist_reset_fail_counter(struct desync_profile *dp, const char *hostname, const char *client_ip_port, t_l7proto l7proto)
 {

tpws/tamper.h

@@ -9,12 +9,6 @@
 #define SPLIT_FLAG_DISORDER	0x01
 #define SPLIT_FLAG_OOB		0x02
 
-typedef enum {UNKNOWN=0, HTTP, TLS} t_l7proto;
-#define L7_PROTO_HTTP	1
-#define L7_PROTO_TLS	2
-#define L7_PROTO_UNKNOWN 0x80000000
-const char *l7proto_str(t_l7proto l7);
-
 typedef struct
 {
 	// common state
@@ -28,7 +22,7 @@ typedef struct
 
 void apply_desync_profile(t_ctrack *ctrack, const struct sockaddr *dest);
 
-void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,size_t segment_buffer_size,size_t *size, size_t *split_pos, uint8_t *split_flags);
+void tamper_out(t_ctrack *ctrack, const struct sockaddr *dest, uint8_t *segment,size_t segment_buffer_size,size_t *size, size_t *multisplit_pos, int *multisplit_count, uint8_t *split_flags);
 void tamper_in(t_ctrack *ctrack, const struct sockaddr *client, uint8_t *segment,size_t segment_buffer_size,size_t *size);
 // connection reset by remote leg
 void rst_in(t_ctrack *ctrack, const struct sockaddr *client);

tpws/tpws.c

@@ -182,9 +182,8 @@ static void exithelp(void)
 		" --hostlist-auto-fail-time=<int>\t; all failed attemps must be within these seconds (default : %d)\n"
 		" --hostlist-auto-debug=<logfile>\t; debug auto hostlist positives\n"
 		"\nTAMPER:\n"
-		" --split-http-req=method|host\t\t; split at specified logical part of plain http request\n"
+		" --split-pos=N|-N|marker+N|marker-N\t; comma separated list of split positions\n"
-		" --split-tls=sni|sniext|snisld\t\t; split at specified logical part of TLS ClientHello\n"
+		"\t\t\t\t\t; markers: method,host,endhost,sld,endsld,midsld,sniext\n"
-		" --split-pos=<numeric_offset>\t\t; split at specified pos. split-http-req or split-tls take precedence for http.\n"
 		" --split-any-protocol\t\t\t; split not only http and https\n"
 #if defined(BSD) && !defined(__APPLE__)
 		" --disorder[=http|tls]\t\t\t; when splitting simulate sending second fragment first (BSD sends entire message instead of first fragment, this is not good)\n"
@@ -203,8 +202,7 @@ static void exithelp(void)
 		" --methodspace\t\t\t\t; add extra space after method\n"
 		" --methodeol\t\t\t\t; add end-of-line before method\n"
 		" --unixeol\t\t\t\t; replace 0D0A to 0A\n"
-		" --tlsrec=sni|sniext|snisld\t\t; make 2 TLS records. split at specified logical part. don't split if SNI is not present\n"
+		" --tlsrec=N|-N|marker+N|marker-N\t; make 2 TLS records. split records at specified position.\n"
-		" --tlsrec-pos=<pos>\t\t\t; make 2 TLS records. split at specified pos\n"
 #ifdef __linux__
 		" --mss=<int>\t\t\t\t; set client MSS. forces server to split messages but significantly decreases speed !\n"
 #endif
@@ -276,29 +274,131 @@ void save_default_ttl(void)
 	}
 }
 
-bool parse_httpreqpos(const char *s, enum httpreqpos *pos)
+static bool parse_httpreqpos(const char *s, struct proto_pos *sp)
 {
 	if (!strcmp(s, "method"))
-		*pos = httpreqpos_method;
+	{
+		sp->marker = PM_HTTP_METHOD;
+		sp->pos=2;
+	}
 	else if (!strcmp(s, "host"))
-		*pos = httpreqpos_host;
+	{
+		sp->marker = PM_HOST;
+		sp->pos=1;
+	}
 	else
 		return false;
 	return true;
 }
-bool parse_tlspos(const char *s, enum tlspos *pos)
+static bool parse_tlspos(const char *s, struct proto_pos *sp)
 {
 	if (!strcmp(s, "sni"))
-		*pos = tlspos_sni;
+	{
+		sp->marker = PM_HOST;
+		sp->pos=1;
+	}
 	else if (!strcmp(s, "sniext"))
-		*pos = tlspos_sniext;
+	{
+		sp->marker = PM_SNI_EXT;
+		sp->pos=1;
+	}
 	else if (!strcmp(s, "snisld"))
-		*pos = tlspos_snisld;
+	{
+		sp->marker = PM_HOST_MIDSLD;
+		sp->pos=0;
+	}
 	else
 		return false;
 	return true;
 }
 
+static bool parse_int16(const char *p, int16_t *v)
+{
+	if (*p=='+' || *p=='-' || *p>='0' && *p<='9')
+	{
+		int i = atoi(p);
+		*v = (int16_t)i;
+		return *v==i; // check overflow
+	}
+	return false;
+}
+static bool parse_posmarker(const char *opt, uint8_t *posmarker)
+{
+	if (!strcmp(opt,"host"))
+		*posmarker = PM_HOST;
+	else if (!strcmp(opt,"endhost"))
+		*posmarker = PM_HOST_END;
+	else if (!strcmp(opt,"sld"))
+		*posmarker = PM_HOST_SLD;
+	else if (!strcmp(opt,"midsld"))
+		*posmarker = PM_HOST_MIDSLD;
+	else if (!strcmp(opt,"endsld"))
+		*posmarker = PM_HOST_ENDSLD;
+	else if (!strcmp(opt,"method"))
+		*posmarker = PM_HTTP_METHOD;
+	else if (!strcmp(opt,"sniext"))
+		*posmarker = PM_SNI_EXT;
+	else
+		return false;
+	return true;
+}
+static bool parse_split_pos(char *opt, struct proto_pos *split)
+{
+	if (parse_int16(opt,&split->pos))
+	{
+		split->marker = PM_ABS;
+		return !!split->pos;
+	}
+	else
+	{
+		char c,*p=opt;
+		bool b;
+
+		for (; *opt && *opt!='+' && *opt!='-'; opt++);
+		c=*opt; *opt=0;
+		b=parse_posmarker(p,&split->marker);
+		*opt=c;
+		if (!b) return false;
+		if (*opt)
+			return parse_int16(opt,&split->pos);
+		else
+			split->pos = 0;
+	}
+	return true;
+}
+static bool parse_split_pos_list(char *opt, struct proto_pos *splits, int splits_size, int *split_count)
+{
+	char c,*e,*p;
+
+	for (p=opt, *split_count=0 ; p && *split_count<splits_size ; (*split_count)++)
+	{
+		if ((e = strchr(p,',')))
+		{
+			c=*e;
+			*e=0;
+		}
+		if (!parse_split_pos(p,splits+*split_count)) return false;
+		if (e) *e++=c;
+		p = e;
+	}
+	if (p) return false; // too much splits
+	return true;
+}
+static void SplitDebug(void)
+{
+	struct desync_profile_list *dpl;
+	const struct desync_profile *dp;
+	int x;
+	LIST_FOREACH(dpl, &params.desync_profiles, next)
+	{
+		dp = &dpl->dp;
+		for(x=0;x<dp->split_count;x++)
+			VPRINT("profile %d multisplit %s %d\n",dp->n,posmarker_name(dp->splits[x].marker),dp->splits[x].pos);
+		if (!PROTO_POS_EMPTY(&dp->tlsrec))
+			VPRINT("profile %d tlsrec %s %d\n",dp->n,posmarker_name(dp->tlsrec.marker),dp->tlsrec.pos);
+	}
+}
+
 static bool wf_make_l3(char *opt, bool *ipv4, bool *ipv6)
 {
 	char *e,*p,c;
@@ -682,30 +782,46 @@ void parse_params(int argc, char *argv[])
 			params.tamper = true;
 			break;
 		case 23: /* split-http-req */
-			if (!parse_httpreqpos(optarg, &dp->split_http_req))
+			DLOG_CONDUP("WARNING ! --split-http-req is deprecated. use --split-pos with markers.\n",MAX_SPLITS);
+			if (dp->split_count>=MAX_SPLITS)
+			{
+				DLOG_ERR("Too much splits. max splits: %u\n",MAX_SPLITS);
+				exit_clean(1);
+			}
+			if (!parse_httpreqpos(optarg, dp->splits + dp->split_count))
 			{
 				DLOG_ERR("Invalid argument for split-http-req\n");
 				exit_clean(1);
 			}
+			dp->split_count++;
 			params.tamper = true;
 			break;
 		case 24: /* split-tls */
-			if (!parse_tlspos(optarg, &dp->split_tls))
+			// obsolete arg
+			DLOG_CONDUP("WARNING ! --split-tls is deprecated. use --split-pos with markers.\n",MAX_SPLITS);
+			if (dp->split_count>=MAX_SPLITS)
+			{
+				DLOG_ERR("Too much splits. max splits: %u\n",MAX_SPLITS);
+				exit_clean(1);
+			}
+			if (!parse_tlspos(optarg, dp->splits + dp->split_count))
 			{
 				DLOG_ERR("Invalid argument for split-tls\n");
 				exit_clean(1);
 			}
+			dp->split_count++;
 			params.tamper = true;
 			break;
 		case 25: /* split-pos */
-			i = atoi(optarg);
-			if (i>0)
-				dp->split_pos = i;
-			else
 			{
-				DLOG_ERR("Invalid argument for split-pos\n");
+				int ct;
+				if (!parse_split_pos_list(optarg,dp->splits+dp->split_count,MAX_SPLITS-dp->split_count,&ct))
+				{
+					DLOG_ERR("could not parse split pos list or too much positions (before parsing - %u, max - %u) : %s\n",dp->split_count,MAX_SPLITS,optarg);
 					exit_clean(1);
 				}
+				dp->split_count += ct;
+			}
 			params.tamper = true;
 			break;
 		case 26: /* split-any-protocol */
@@ -724,7 +840,6 @@ void parse_params(int argc, char *argv[])
 			}
 			else
 				dp->disorder = true;
-			save_default_ttl();
 			break;
 		case 28: /* oob */
 			if (optarg)
@@ -770,7 +885,7 @@ void parse_params(int argc, char *argv[])
 			params.tamper = true;
 			break;
 		case 34: /* tlsrec */
-			if (!parse_tlspos(optarg, &dp->tlsrec))
+			if (!parse_split_pos(optarg, &dp->tlsrec) && !parse_tlspos(optarg, &dp->tlsrec))
 			{
 				DLOG_ERR("Invalid argument for tlsrec\n");
 				exit_clean(1);
@@ -778,9 +893,11 @@ void parse_params(int argc, char *argv[])
 			params.tamper = true;
 			break;
 		case 35: /* tlsrec-pos */
-			if ((dp->tlsrec_pos = atoi(optarg))>0)
+			// obsolete arg
-				dp->tlsrec = tlspos_pos;
+			i = atoi(optarg);
-			else
+			dp->tlsrec.marker = PM_ABS;
+			dp->tlsrec.pos = (int16_t)i;
+			if (!dp->tlsrec.pos || i!=dp->tlsrec.pos)
 			{
 				DLOG_ERR("Invalid argument for tlsrec-pos\n");
 				exit_clean(1);
@@ -823,8 +940,6 @@ void parse_params(int argc, char *argv[])
 					DLOG_ERR("gzipped auto hostlists are not supported\n");
 					exit_clean(1);
 				}
-				if (params.droproot && chown(optarg, params.uid, -1))
-					DLOG_ERR("could not chown %s. auto hostlist file may not be writable after privilege drop\n", optarg);
 			}
 			if (!(dp->hostlist_auto=RegisterHostlist(dp, false, optarg)))
 			{
@@ -858,8 +973,6 @@ void parse_params(int argc, char *argv[])
 					exit_clean(1);
 				}
 				fclose(F);
-				if (params.droproot && chown(optarg, params.uid, -1))
-					DLOG_ERR("could not chown %s. auto hostlist debug log may not be writable after privilege drop\n", optarg);
 				strncpy(params.hostlist_auto_debuglog, optarg, sizeof(params.hostlist_auto_debuglog));
 				params.hostlist_auto_debuglog[sizeof(params.hostlist_auto_debuglog) - 1] = '\0';
 			}
@@ -881,8 +994,6 @@ void parse_params(int argc, char *argv[])
 						fprintf(stderr, "cannot create %s\n", params.debug_logfile);
 						exit_clean(1);
 					}
-					if (params.droproot && chown(params.debug_logfile, params.uid, -1))
-						fprintf(stderr, "could not chown %s. log file may not be writable after privilege drop\n", params.debug_logfile);
 					if (!params.debug) params.debug = 1;
 					params.debug_target = LOG_TARGET_FILE;
 				}
@@ -1117,16 +1228,21 @@ void parse_params(int argc, char *argv[])
 
 	DLOG_CONDUP("we have %d user defined desync profile(s) and default low priority profile 0\n",desync_profile_count);
 
+	save_default_ttl();
+	if (params.debug_target == LOG_TARGET_FILE && params.droproot && chown(params.debug_logfile, params.uid, -1))
+		fprintf(stderr, "could not chown %s. log file may not be writable after privilege drop\n", params.debug_logfile);
+	if (params.droproot && *params.hostlist_auto_debuglog && chown(params.hostlist_auto_debuglog, params.uid, -1))
+		DLOG_ERR("could not chown %s. auto hostlist debug log may not be writable after privilege drop\n", params.hostlist_auto_debuglog);
 	LIST_FOREACH(dpl, &params.desync_profiles, next)
 	{
 		dp = &dpl->dp;
-		if (dp->split_tls==tlspos_none && dp->split_pos) dp->split_tls=tlspos_pos;
+		if (params.skip_nodelay && dp->split_count)
-		if (dp->split_http_req==httpreqpos_none && dp->split_pos) dp->split_http_req=httpreqpos_pos;
-		if (params.skip_nodelay && (dp->split_tls || dp->split_http_req || dp->split_pos))
 		{
 			DLOG_ERR("Cannot split with --skip-nodelay\n");
 			exit_clean(1);
 		}
+		if (params.droproot && dp->hostlist_auto && chown(dp->hostlist_auto->filename, params.uid, -1))
+			DLOG_ERR("could not chown %s. auto hostlist file may not be writable after privilege drop\n", dp->hostlist_auto->filename);
 	}
 
 	if (!LoadAllHostLists())
@@ -1143,6 +1259,9 @@ void parse_params(int argc, char *argv[])
 	VPRINT("\nlists summary:\n");
 	HostlistsDebug();
 	IpsetsDebug();
+
+	VPRINT("\nsplits summary:\n");
+	SplitDebug();
 	VPRINT("\n");
 
 #ifndef __OpenBSD__

tpws/tpws_conn.c

@@ -24,6 +24,7 @@
 #include "helpers.h"
 #include "hostlist.h"
 
+#define PKTDATA_MAXDUMP 32
 
 // keep separate legs counter. counting every time thousands of legs can consume cpu
 static int legs_local, legs_remote;
@@ -92,26 +93,43 @@ static bool socks_send_rep_errno(uint8_t ver, int fd, int errn)
 	return ver==5 ? socks5_send_rep_errno(fd,errn) : socks4_send_rep_errno(fd, errn);
 }
 
+static void packet_debug(const uint8_t *data, size_t sz)
+{
+	hexdump_limited_dlog(data, sz, PKTDATA_MAXDUMP); VPRINT("\n");
+}
+
+
+static bool cork(int fd, int enable)
+{
+#ifdef __linux__
+	int e = errno;
+	if (setsockopt(fd, SOL_TCP, TCP_CORK, &enable, sizeof(enable))<0)
+	{
+		DLOG_PERROR("setsockopt (TCP_CORK)");
+		errno = e;
+		return false;
+	}
+	errno = e;
+#endif
+	return true;
+}
 
 ssize_t send_with_ttl(int fd, const void *buf, size_t len, int flags, int ttl)
 {
 	ssize_t wr;
 
-	if (ttl)
+	if (!params.skip_nodelay)
 	{
+		int ttl_apply = ttl ? ttl : params.ttl_default;
 		DBGPRINT("send_with_ttl %d fd=%d\n",ttl,fd);
-		if (!set_ttl_hl(fd, ttl))
+		if (!set_ttl_hl(fd, ttl_apply))
 			//DLOG_ERR("could not set ttl %d to fd=%d\n",ttl,fd);
-			DLOG_ERR("could not set ttl %d to fd=%d\n",ttl,fd);
+			DLOG_ERR("could not set ttl %d to fd=%d\n",ttl_apply,fd);
+		cork(fd,true);
 	}
 	wr = send(fd, buf, len, flags);
-	if (ttl)
+	if (!params.skip_nodelay)
-	{
+		cork(fd,false);
-		int e=errno;
-		if (!set_ttl_hl(fd, params.ttl_default))
-			DLOG_ERR("could not set ttl %d to fd=%d\n",params.ttl_default,fd);
-		errno=e;
-	}
 	return wr;
 }
 
@@ -308,19 +326,18 @@ bool set_socket_buffers(int fd, int rcvbuf, int sndbuf)
 	if (rcvbuf && setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(int)) <0)
 	{
 		DLOG_PERROR("setsockopt (SO_RCVBUF)");
-		close(fd);
 		return false;
 	}
 	if (sndbuf && setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sndbuf, sizeof(int)) <0)
 	{
 		DLOG_PERROR("setsockopt (SO_SNDBUF)");
-		close(fd);
 		return false;
 	}
 	dbgprint_socket_buffers(fd);
 	return true;
 }
 
+
 static bool proxy_remote_conn_ack(tproxy_conn_t *conn, int sock_err)
 {
 	// if proxy mode acknowledge connection request
@@ -393,7 +410,10 @@ static int connect_remote(const struct sockaddr *remote_addr, int mss)
 		return -1;
 	}
 	if (!set_socket_buffers(remote_fd, params.remote_rcvbuf, params.remote_sndbuf))
+	{
+		close(remote_fd);
 		return -1;
+	}
 	if (!set_keepalive(remote_fd))
 	{
 		DLOG_PERROR("set_keepalive");
@@ -1068,9 +1088,9 @@ static bool in_tamper_out_range(tproxy_conn_t *conn)
 		 
 }
 
-static void tamper(tproxy_conn_t *conn, uint8_t *segment, size_t segment_buffer_size, size_t *segment_size, size_t *split_pos, uint8_t *split_flags)
+static void tamper(tproxy_conn_t *conn, uint8_t *segment, size_t segment_buffer_size, size_t *segment_size, size_t *multisplit_pos, int *multisplit_count, uint8_t *split_flags)
 {
-	*split_pos=0;
+	if (multisplit_count) *multisplit_count=0;
 	if (params.tamper)
 	{
 		if (conn->remote)
@@ -1081,26 +1101,26 @@ static void tamper(tproxy_conn_t *conn, uint8_t *segment, size_t segment_buffer_
 		else
 		{
 			if (in_tamper_out_range(conn))
-				tamper_out(&conn->track,(struct sockaddr*)&conn->dest,segment,segment_buffer_size,segment_size,split_pos,split_flags);
+				tamper_out(&conn->track,(struct sockaddr*)&conn->dest,segment,segment_buffer_size,segment_size,multisplit_pos,multisplit_count,split_flags);
 		}
 	}
 }
 
 // buffer must have at least one extra byte for OOB
-static ssize_t send_or_buffer_oob(send_buffer_t *sb, int fd, uint8_t *buf, size_t len, int ttl, bool oob, uint8_t oob_byte)
+static ssize_t send_oob(int fd, uint8_t *buf, size_t len, int ttl, bool oob, uint8_t oob_byte)
 {
 	ssize_t wr;
 	if (oob)
 	{
-		VPRINT("Sending OOB byte %02X\n", oob_byte);
 		uint8_t oob_save;
 		oob_save = buf[len];
 		buf[len] = oob_byte;
-		wr = send_or_buffer(sb, fd, buf, len+1, MSG_OOB, ttl);
+		wr = send_with_ttl(fd, buf, len+1, MSG_OOB, ttl);
 		buf[len] = oob_save;
+		if (wr<0 && errno==EAGAIN) wr=0;
 	}
 	else
-		wr = send_or_buffer(sb, fd, buf, len, 0, ttl);
+		wr = send_with_ttl(fd, buf, len, 0, ttl);
 	return wr;
 }
 
@@ -1186,36 +1206,53 @@ static bool handle_epoll(tproxy_conn_t *conn, struct tailhead *conn_list, uint32
 #endif
 		{
 			// incoming data from local leg
-			uint8_t buf[RD_BLOCK_SIZE + 5];
+			uint8_t buf[RD_BLOCK_SIZE + 6];
 
 			rd = recv(conn->fd, buf, RD_BLOCK_SIZE, MSG_DONTWAIT);
 			DBGPRINT("recv fd=%d rd=%zd err=%d\n",conn->fd, rd,errno);
 			if (rd<0 && errno==EAGAIN) rd=0;
 			if (rd>0)
 			{
-				size_t split_pos;
+				size_t multisplit_pos[MAX_SPLITS];
+				int multisplit_count;
+
 				uint8_t split_flags;
 
 				bs = rd;
 
 				// tamper needs to know stream position of the block start
-				tamper(conn, buf, sizeof(buf), &bs, &split_pos, &split_flags);
+				tamper(conn, buf, sizeof(buf), &bs, multisplit_pos, &multisplit_count, &split_flags);
 				// increase after tamper
 				conn->tnrd++;
 				conn->trd+=rd;
 
-				if (split_pos && bs<sizeof(buf) && split_pos<sizeof(buf))
+				if (multisplit_count)
 				{
-					VPRINT("Splitting at pos %zu%s\n", split_pos, (split_flags & SPLIT_FLAG_DISORDER) ? " with disorder" : "");
+					ssize_t from,to,len;
+					int i;
+					bool bApplyDisorder, bApplyOOB;
+					for (i=0,from=0;i<=multisplit_count;i++)
+					{
+						to = i==multisplit_count ? bs : multisplit_pos[i];
 
-					wr = send_or_buffer_oob(conn->partner->wr_buf, conn->partner->fd, buf, split_pos, !!(split_flags & SPLIT_FLAG_DISORDER), !!(split_flags & SPLIT_FLAG_OOB), conn->track.dp ? conn->track.dp->oob_byte : 0);
+						bApplyDisorder = !(i & 1) && i<multisplit_count && (split_flags & SPLIT_FLAG_DISORDER);
-					DBGPRINT("send_or_buffer(1) fd=%d wr=%zd err=%d\n",conn->partner->fd,wr,errno);
+						bApplyOOB = i==0 && (split_flags & SPLIT_FLAG_OOB);
-					if (wr >= 0)
+						len = to-from;
-					{
+						VPRINT("Sending multisplit part %d %zd-%zd (len %zd)%s%s : ", i+1, from, to, len, bApplyDisorder ? " with disorder" : "", bApplyOOB ? " with OOB" : "");
+						packet_debug(buf+from,len);
+						wr = send_oob(conn->partner->fd, buf+from, len, bApplyDisorder, bApplyOOB, conn->track.dp ? conn->track.dp->oob_byte : 0);
+						if (wr<0) break;
 						conn->partner->twr += wr;
-						wr = send_or_buffer(conn->partner->wr_buf + 1, conn->partner->fd, buf + split_pos, bs - split_pos, 0, 0);
+						if (wr<len)
-						DBGPRINT("send_or_buffer(2) fd=%d wr=%zd err=%d\n",conn->partner->fd,wr,errno);
+						{
+							from+=wr;
+							VPRINT("Cannot send part %d immediately. only %zd bytes were sent (%zd left in segment). cancelling split.\n", i+1, wr, bs-from);
+							wr = send_or_buffer(conn->partner->wr_buf, conn->partner->fd, buf+from, bs-from, 0, 0);
 							if (wr>0) conn->partner->twr += wr;
+							break;
+						}
+
+						from = to;
 					}
 				}
 				else
@@ -1279,7 +1316,7 @@ static bool read_all_and_buffer(tproxy_conn_t *conn, int buffer_number)
 		DBGPRINT("read_all_and_buffer(%d) numbytes=%d\n",buffer_number,numbytes);
 		if (numbytes>0)
 		{
-			if (send_buffer_create(conn->partner->wr_buf+buffer_number, NULL, numbytes, 5, 0, 0))
+			if (send_buffer_create(conn->partner->wr_buf+buffer_number, NULL, numbytes, 6, 0, 0))
 			{
 				ssize_t rd = recv(conn->fd, conn->partner->wr_buf[buffer_number].data, numbytes, MSG_DONTWAIT);
 				if (rd>0)
@@ -1289,10 +1326,7 @@ static bool read_all_and_buffer(tproxy_conn_t *conn, int buffer_number)
 
 					conn->partner->bFlowOut = true;
 
-					size_t split_pos;
+					tamper(conn, conn->partner->wr_buf[buffer_number].data, numbytes+6, &conn->partner->wr_buf[buffer_number].len, NULL, NULL, NULL);
-					uint8_t split_flags;
-
-					tamper(conn, conn->partner->wr_buf[buffer_number].data, numbytes+5, &conn->partner->wr_buf[buffer_number].len, &split_pos, &split_flags);
 
 					if (epoll_update_flow(conn->partner))
 						return true;
@@ -1369,7 +1403,7 @@ static bool handle_resolve_pipe(tproxy_conn_t **conn, struct tailhead *conn_list
 	else if (rd!=sizeof(void*))
 	{
 		// partial pointer read is FATAL. in any case it will cause pointer corruption and coredump
-		DLOG_ERR("resolve_pipe not full read %zu\n",rd);
+		DLOG_ERR("resolve_pipe not full read %zd\n",rd);
 		exit(1000);
 	}
 	b = resolve_complete(ri, conn_list);