Use memmove for overlapping region

man/3proxy.cfg.5

@@ -199,6 +199,13 @@ is disabled even when built, because current Linux does not implement
 SPLICE_F_MOVE, so no real zero-copy takes place and the read/write path is faster
 for most traffic. Rebuild with -DWITHSPLICE to make -s available, -s0 disables it
 explicitly.
+.br
+.B -C
+ (for TCP services) keep the session until both sides close the connection
+(TCP half-close). By default a connection closed by any of the sides terminates
+the session, buffered data is delivered before the sockets are closed. Half-close
+is required for the protocols where one of the sides closes its sending side and
+expects the answer, it may cause the sockets to be kept in CLOSE_WAIT state.
 .br
  (for dnspr) simple, do not use resolver and 3proxy cache, always use external DNS server.
 .br

src/proxymain.c

@@ -329,6 +329,8 @@ int MODULEMAINFUNC (int argc, char** argv){
 #endif
 #ifdef WITHSPLICE
 	" -s Use splice() - no filtering for data, off by default\n"
+	" -C keep the session until both sides close the connection (TCP half-close),\n"
+	"    by default connection closed by any of the sides terminates the session\n"
 #endif
 	"-g(GRACE_TRAFF,GRACE_NUM,GRACE_DELAY) - delay GRACE_DELAY milliseconds before polling if average polling size below  GRACE_TRAFF bytes and GRACE_NUM read operations in single directions are detected within 1 second to minimize polling\n"
 	" -fFORMAT logging format (see documentation)\n"
@@ -596,6 +598,9 @@ int MODULEMAINFUNC (int argc, char** argv){
 		case 'g':
 			sscanf(argv[i]+2, "%d,%d,%d", &srv.gracetraf, &srv.gracenum, &srv.gracedelay);
 			break;
+		case 'C':
+			srv.halfclose = *(argv[i]+2)? atoi(argv[i]+2) : 1;
+			break;
 		case 's':
 #ifdef WITHSPLICE
 			if(isudp || srv.service == S_ADMIN)
@@ -1247,6 +1252,7 @@ void srvinit(struct srvparam * srv, struct clientparam *param){
 #ifdef WITHSPLICE
  srv->usesplice = 0;
 #endif
+ srv->halfclose = 0;
  memset(param, 0, sizeof(struct clientparam));
  param->srv = srv;
  param->version = srv->version;

src/sockgetchar.c

@@ -171,12 +171,13 @@ int sockgetlinebuf(struct clientparam * param, DIRECTION which, unsigned char *
 		if(delim != EOF){
 			unsigned char *d = (unsigned char *)memchr(base + *offp, delim, n);
 			if(d) n = (int)(d - (base + *offp)) + 1;
-			memcpy(buf + i, base + *offp, n);
+			/* caller may use param->srvbuf / param->clibuf as buf */
+			memmove(buf + i, base + *offp, n);
 			i += n; *offp += n;
 			if(d || i >= bufsize) return i;
 		}
 		else {
-			memcpy(buf + i, base + *offp, n);
+			memmove(buf + i, base + *offp, n);
 			i += n; *offp += n;
 			if(i >= bufsize) return i;
 		}

src/sockmap.c

@@ -44,7 +44,13 @@ ssize_t splice(int fd_in, loff_t *off_in, int fd_out, loff_t *off_out, size_t le
 #define MIN(a,b) ((a>b)?b:a)
 #define RETURN(xxx) { res = xxx; goto CLEANRET; }
 
+/* Unless half-close is requested for the service, a connection closed by any
+   of the sides terminates the session, remaining buffered data is delivered
+   before the sockets are closed. */
+#define SESSIONEND (!halfclose && (CLIENTTERMREAD || SERVERTERMREAD))
+
 int sockmap(struct clientparam * param, int timeo, int usesplice){
+ int halfclose = param->srv->halfclose;
  uint64_t fromclient=0x7fffffffffffffff, fromserver =0x7fffffffffffffff;
  uint64_t inclientbuf = 0, inserverbuf = 0;
  int FROMCLIENT = 1, TOCLIENTBUF = 1, TOSERVER = 1, 
@@ -129,13 +135,13 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 #ifdef WITHSPLICE
 		|| inserverpipe
 #endif
-		|| (!SERVERTERMREAD )))
+		|| (!SERVERTERMREAD && !SESSIONEND)))
 	||
 	((!SERVERTERMWRITE) && fromclient && (inclientbuf
 #ifdef WITHSPLICE
 		|| inclientpipe
 #endif
-		|| (!CLIENTTERMREAD )))
+		|| (!CLIENTTERMREAD && !SESSIONEND)))
  ){
 
 
@@ -354,7 +360,7 @@ log(logbuf);
 				}
 			}
 		}
-		if(fromclient>inclientpipe && FROMCLIENT && TOCLIENTPIPE){
+		if(fromclient>inclientpipe && FROMCLIENT && TOCLIENTPIPE && !SESSIONEND){
 			int error;
 			socklen_t len=sizeof(error);
 #ifdef WITHLOG
@@ -396,7 +402,7 @@ log("done read from client to pipe");
 				continue;
 			}
 		}
-		if(fromserver > inserverpipe && FROMSERVER && TOSERVERPIPE){
+		if(fromserver > inserverpipe && FROMSERVER && TOSERVERPIPE && !SESSIONEND){
 			int error; 
 			socklen_t len=sizeof(error);
 			errno = 0;
@@ -449,7 +455,7 @@ log("done read from server to pipe\n");
 	else
 #endif
 	{
-		if(fromclient > inclientbuf && FROMCLIENT && TOCLIENTBUF){
+		if(fromclient > inclientbuf && FROMCLIENT && TOCLIENTBUF && !SESSIONEND){
 #ifdef WITHLOG
 log("read from client to buf");
 #endif
@@ -482,7 +488,7 @@ log("done read from client to buf");
 			}
 		}
 
-		if(fromserver > inserverbuf && FROMSERVER && TOSERVERBUF){
+		if(fromserver > inserverbuf && FROMSERVER && TOSERVERBUF && !SESSIONEND){
 #ifdef WITHLOG
 log("read from server to buf");
 #endif
@@ -547,7 +553,7 @@ log("done read from server to buf");
 //		if(!CLIENTTERMREAD || !CLIENTTERMWRITE){
 			if(!after){
 				fds[fdsc].fd = param->clisock;
-				if(fromclient && !CLIENTTERMREAD && !FROMCLIENT && ((
+				if(fromclient && !CLIENTTERMREAD && !FROMCLIENT && !SESSIONEND && ((
 #ifdef WITHSPLICE
 					!usesplice &&
 #endif
@@ -607,7 +613,7 @@ log("ready to write to client");
 //		if(!SERVERTERMREAD || !SERVERTERMWRITE){
 			if(!after){
 				fds[fdsc].fd = param->remsock;
-				if(fromserver && !SERVERTERMREAD && !FROMSERVER && ((
+				if(fromserver && !SERVERTERMREAD && !FROMSERVER && !SESSIONEND && ((
 #ifdef WITHSPLICE
 					!usesplice &&
 #endif
@@ -827,3 +833,4 @@ CLEANRET:
 
  return res;
 }
+#undef SESSIONEND

src/structures.h

@@ -551,6 +551,7 @@ struct srvparam {
 #ifdef WITHSPLICE
 	int usesplice;
 #endif
+	int halfclose;
 	unsigned bufsize;
 	unsigned authcachetype, authcachetime;
 	unsigned logdumpsrv, logdumpcli;