added 2 more parameters to sys::write()

adding a tcp proxy script

hawk/lib/mod-sys.c

@@ -713,13 +713,24 @@ static int fnc_write (hawk_rtx_t* rtx, const hawk_fnc_info_t* fi)
 	{
 		hawk_bch_t* dptr;
 		hawk_oow_t dlen;
+		hawk_ooi_t startpos = 0, maxlen = HAWK_TYPE_MAX(hawk_ooi_t);
 		hawk_val_t* a1;
 
+		if (hawk_rtx_getnargs(rtx) >= 3 && hawk_rtx_valtoint(rtx, hawk_rtx_getarg(rtx, 2), &startpos) <= -1 || startpos < 0) startpos = 0;
+		else if (startpos > 1) startpos--; /* this position is 1-based */
+
+		if (hawk_rtx_getnargs(rtx) >= 4 && hawk_rtx_valtoint(rtx, hawk_rtx_getarg(rtx, 3), &maxlen) <= -1) maxlen = HAWK_TYPE_MAX(hawk_ooi_t);
+		else if (maxlen < 0) maxlen = 0;
+
 		a1 = hawk_rtx_getarg(rtx, 1);
 		dptr = hawk_rtx_getvalbcstr(rtx, a1, &dlen);
 		if (dptr)
 		{
-			rx = write(sys_node->ctx.u.file.fd, dptr, dlen);
+			if (dlen > maxlen) dlen = maxlen;
+			if (startpos >= dlen) startpos = dlen;
+			dlen -= startpos;
+
+			rx = write(sys_node->ctx.u.file.fd, &dptr[startpos], dlen);
 			if (rx <= -1) rx = set_error_on_sys_list_with_errno(rtx, sys_list, HAWK_T("unable to write"));
 			hawk_rtx_freevalbcstr (rtx, a1, dptr);
 		}
@@ -4280,7 +4291,7 @@ static fnctab_t fnctab[] =
 	{ HAWK_T("unsetenv"),    { { 1, 1, HAWK_NULL       }, fnc_unsetenv,    0  } },
 	{ HAWK_T("wait"),        { { 1, 3, HAWK_T("vrv")   }, fnc_wait,        0  } },
 	{ HAWK_T("waitonmux"),   { { 2, 2, HAWK_T("vv")    }, fnc_waitonmux,   0  } },
-	{ HAWK_T("write"),       { { 2, 2, HAWK_NULL       }, fnc_write,       0  } },
+	{ HAWK_T("write"),       { { 2, 4, HAWK_NULL       }, fnc_write,       0  } },
 	{ HAWK_T("writelog"),    { { 2, 2, HAWK_NULL       }, fnc_writelog,    0  } }
 };
 

hawk/scripts/tcp-proxy.awk

@@ -0,0 +1,267 @@
+@pragma entry main
+@pragma implicit off
+
+function break_bridge_by_local_fd (&localtab, &remotetab, fd, mx)
+{
+	@local r;
+	r = localtab[fd];
+	sys::delfrommux (mx, fd);
+	sys::delfrommux (mx, r);
+	sys::close (fd);
+	sys::close (r);
+	delete localtab[fd];
+	delete localtab[fd,"pending"];
+	delete remotetab[r];
+	delete remotetab[r,"connecting"];
+	delete remotetab[r,"pending"];
+}
+
+function break_bridge_by_remote_fd (localtab, remotetab, fd, mx)
+{
+	@local l;
+	l = remotetab[fd];
+	sys::delfrommux (mx, l);
+	sys::delfrommux (mx, fd);
+	sys::close (l);
+	sys::close (fd);
+	delete localtab[l];
+	delete localtab[l,"pending"];
+	delete remotetab[fd];
+	delete remotetab[fd,"connecting"];
+	delete remotetab[fd,"pending"];
+}
+
+function bridge_remote_to_local (localtab, remotetab, fd, mx)
+{
+	@local len, buf;
+
+	len = sys::read(fd, buf, 8096);
+	if (len <= 0)
+	{
+		print "closing read error ", fd;
+		break_bridge_by_remote_fd (localtab, remotetab, fd, mx);
+	}
+	else
+	{
+		do
+		{
+			@local x;
+
+			x = sys::write(remotetab[fd], buf);
+			if (x == sys::RC_EAGAIN)
+			{
+				remotetab[fd,"pending"] = remotetab[fd,"pending"] %% buf;
+				break;
+			}
+			else if (x <= -1)
+			{
+				break_bridge_by_remote_fd (localtab, remotetab, fd, mx);
+				break;
+			}
+
+			len -= x;
+			if (len <= 0) break;
+
+			buf = substr(buf, x + 1);
+		}
+		while (1);
+	}
+}
+
+function bridge_local_to_remote (localtab, remotetab, fd, mx)
+{
+	@local len, buf;
+
+	len = sys::read(fd, buf, 8096);
+	if (len <= 0)
+	{
+		print "closing read error ", fd;
+		break_bridge_by_local_fd (localtab, remotetab, fd, mx);
+	}
+	else
+	{
+printf ("ABOUT TO WRITE TO REMOTE........\n");
+		do
+		{
+			@local x;
+
+			x = sys::write(localtab[fd], buf);
+			if (x == sys::RC_EAGAIN)
+			{
+				localtab[fd,"pending"] = localtab[fd,"pending"] %% buf;
+				## TODO: MOD mux for writing..
+				break;
+			}
+			else if (x <= -1)
+			{
+				break_bridge_by_local_fd (localtab, remotetab, fd, mx);
+				break;
+			}
+
+			len -= x;
+			if (len <= 0) break;
+
+			buf = substr(buf, x + 1);
+		}
+		while (1);
+	}
+}
+
+function serve_connections (mx, ss, remoteaddr)
+{
+	@local localtab, remotetab
+
+	while (1)
+	{
+		@local x, i;
+
+		if ((x = sys::waitonmux(mx, 3.10)) <= -1)
+		{
+			print "Error: problem while waiting on multiplexer -", sys::errmsg();
+			break;
+		}
+
+		if (x == 0) continue; ## timed out
+
+
+		for (i = 0; i < x; i++)
+		{
+			@local fd, evmask;
+
+			if (sys::getmuxevt(mx, i, fd, evmask) <= -1) continue;
+
+			if (fd == ss)
+			{
+				## server socket event
+				@local l, r;
+
+				l = sys::accept(ss, sys::SOCK_CLOEXEC | sys::SOCK_NONBLOCK);
+				if (l <= -1)
+				{
+					print "Error: failed to accept connection -", sys::errmsg();
+				}
+				else
+				{
+					r = sys::socket(sys::AF_INET6, sys::SOCK_STREAM | sys::SOCK_CLOEXEC | sys::SOCK_NONBLOCK, 0);
+					if (r <= -1)
+					{
+						print "Error: unable to create remote socket for local socket", l, "-", sys::errmsg();
+						sys::close(l);
+					}
+					else 
+					{
+						@local x;
+						x = sys::connect(r, remoteaddr);
+						if ((x <= -1 && x != sys::RC_EINPROG) || sys::addtomux(mx, r, sys::MUX_EVT_OUT) <= -1)
+						{
+print "Unable to conneect to remote...", sys::errmsg();
+							sys::close (r);
+							sys::close (l);
+						}
+						else
+						{
+							localtab[l] = r;
+							remotetab[r] = l;
+							remotetab[r,"connecting"] = 1;
+printf ("NEW SESSION %d %d\n", l, r);
+						}
+					}
+				}
+			}
+			else
+			{
+				## event on a client socket
+				if (fd in remotetab)
+				{
+					if (evmask & (sys::MUX_EVT_HUP | sys::MUX_EVT_ERR))
+					{
+						print "closing HUP ERR", fd;
+						break_bridge_by_remote_fd (localtab, remotetab, fd, mx);
+					}
+					else
+					{
+						if (evmask & sys::MUX_EVT_OUT)
+						{
+							if ((fd,"connecting") in remotetab)
+							{
+								## remote connected
+								sys::addtomux (mx, remotetab[fd], sys::MUX_EVT_IN);
+								sys::modinmux (mx, fd, sys::MUX_EVT_IN);
+								delete remotetab[fd,"connecting"];
+							}
+						}
+
+						if (evmask & sys::MUX_EVT_IN)
+						{
+							bridge_remote_to_local (localtab, remotetab, fd, mx);
+						}
+					}
+				}
+
+				if (fd in localtab)
+				{
+					if (evmask & (sys::MUX_EVT_HUP | sys::MUX_EVT_ERR))
+					{
+						print "closing HUP ERR local", fd;
+						break_bridge_by_local_fd (localtab, remotetab, fd, mx);
+					}
+					else if (evmask & sys::MUX_EVT_IN)
+					{
+						print "event on " fd;
+						bridge_local_to_remote (localtab, remotetab, fd, mx);
+					}
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+function main (localaddr, remoteaddr, c)
+{
+	@local ss, mx;
+
+	if (ARGC != 3)
+	{
+		printf ("Usage: %s local-address remote-address\n", ARGV[0]); ## TODO: add SCRIPTNAME to hawk interpreter
+		return -1;
+	}
+
+	mx = sys::openmux();
+	if (mx <= -1)
+	{
+		print "Error: unable to create multiplexer -", sys::errmsg();
+		return -1;
+	}
+
+	ss = sys::socket(sys::AF_INET6, sys::SOCK_STREAM | sys::SOCK_CLOEXEC | sys::SOCK_NONBLOCK, 0);
+	if (ss <= -1)
+	{
+		print "Error: unable to create socket -", sys::errmsg();
+		return -1;
+	}
+
+	sys::setsockopt(ss, sys::SOL_SOCKET, sys::SO_REUSEADDR, 1);
+	sys::setsockopt(ss, sys::SOL_SOCKET, sys::SO_REUSEPORT, 1);
+
+	if (sys::bind(ss, localaddr) <= -1 || sys::listen(ss, 0) <= -1)
+	{
+		print "Error: socket error -", sys::errmsg();
+		sys::close (ss);
+		return -1;
+	}
+
+	if (sys::addtomux(mx, ss, sys::MUX_EVT_IN) <= -1)
+	{
+		print "Error: unable to add server socket to multiplexer -", sys::errmsg();
+		sys::close (ss);
+		return -1;
+	}
+
+	serve_connections (mx, ss, remoteaddr);
+
+	sys::delfrommux (mx, ss);
+	sys::close (ss);
+	sys::close (mx);
+}