Add support for read configuration from file

2017-11-29 13:39:40 +03:00 · 2017-11-29 13:39:40 +03:00 · 3ea208491a
parent 7fb5309551
commit 3ea208491a
12 changed files with 514 additions and 131 deletions
--- a/.cproject
+++ b/.cproject
@ -1,7 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<?fileVersion 4.0.0?>
-
-<cproject storage_type_id="org.eclipse.cdt.core.XmlProjectDescriptionStorage">
+<?fileVersion 4.0.0?><cproject storage_type_id="org.eclipse.cdt.core.XmlProjectDescriptionStorage">
 	<storageModule moduleId="org.eclipse.cdt.core.settings">
 		<cconfiguration id="cdt.managedbuild.toolchain.gnu.base.1826992774">
 			<storageModule buildSystemId="org.eclipse.cdt.managedbuilder.core.configurationDataProvider" id="cdt.managedbuild.toolchain.gnu.base.1826992774" moduleId="org.eclipse.cdt.core.settings" name="Default">
@ -16,17 +14,28 @@
 				</extensions>
 			</storageModule>
 			<storageModule moduleId="cdtBuildSystem" version="4.0.0">
-				<configuration buildProperties="" id="cdt.managedbuild.toolchain.gnu.base.1826992774" name="Default" parent="org.eclipse.cdt.build.core.emptycfg">
+				<configuration buildProperties="" description="" id="cdt.managedbuild.toolchain.gnu.base.1826992774" name="Default" parent="org.eclipse.cdt.build.core.emptycfg">
 					<folderInfo id="cdt.managedbuild.toolchain.gnu.base.1826992774.1618506567" name="/" resourcePath="">
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-							<builder id="cdt.managedbuild.target.gnu.builder.base.751022712" managedBuildOn="false" name="Gnu Make Builder.Default" superClass="cdt.managedbuild.target.gnu.builder.base"/>
+							<builder id="cdt.managedbuild.target.gnu.builder.base.751022712" keepEnvironmentInBuildfile="false" managedBuildOn="false" name="Gnu Make Builder" superClass="cdt.managedbuild.target.gnu.builder.base"/>
 							<tool id="cdt.managedbuild.tool.gnu.archiver.base.1388164087" name="GCC Archiver" superClass="cdt.managedbuild.tool.gnu.archiver.base"/>
-							<tool id="cdt.managedbuild.tool.gnu.cpp.compiler.base.1875165406" name="GCC C++ Compiler" superClass="cdt.managedbuild.tool.gnu.cpp.compiler.base"/>
-							<tool id="cdt.managedbuild.tool.gnu.c.compiler.base.1454341581" name="GCC C Compiler" superClass="cdt.managedbuild.tool.gnu.c.compiler.base"/>
+							<tool id="cdt.managedbuild.tool.gnu.cpp.compiler.base.1875165406" name="GCC C++ Compiler" superClass="cdt.managedbuild.tool.gnu.cpp.compiler.base">
+								<inputType id="cdt.managedbuild.tool.gnu.cpp.compiler.input.437218346" superClass="cdt.managedbuild.tool.gnu.cpp.compiler.input"/>
+							</tool>
+							<tool id="cdt.managedbuild.tool.gnu.c.compiler.base.1454341581" name="GCC C Compiler" superClass="cdt.managedbuild.tool.gnu.c.compiler.base">
+								<inputType id="cdt.managedbuild.tool.gnu.c.compiler.input.722267304" superClass="cdt.managedbuild.tool.gnu.c.compiler.input"/>
+							</tool>
 							<tool id="cdt.managedbuild.tool.gnu.c.linker.base.2010478517" name="GCC C Linker" superClass="cdt.managedbuild.tool.gnu.c.linker.base"/>
-							<tool id="cdt.managedbuild.tool.gnu.cpp.linker.base.970100266" name="GCC C++ Linker" superClass="cdt.managedbuild.tool.gnu.cpp.linker.base"/>
-							<tool id="cdt.managedbuild.tool.gnu.assembler.base.27610334" name="GCC Assembler" superClass="cdt.managedbuild.tool.gnu.assembler.base"/>
+							<tool id="cdt.managedbuild.tool.gnu.cpp.linker.base.970100266" name="GCC C++ Linker" superClass="cdt.managedbuild.tool.gnu.cpp.linker.base">
+								<inputType id="cdt.managedbuild.tool.gnu.cpp.linker.input.177254843" superClass="cdt.managedbuild.tool.gnu.cpp.linker.input">
+									<additionalInput kind="additionalinputdependency" paths="$(USER_OBJS)"/>
+									<additionalInput kind="additionalinput" paths="$(LIBS)"/>
+								</inputType>
+							</tool>
+							<tool id="cdt.managedbuild.tool.gnu.assembler.base.27610334" name="GCC Assembler" superClass="cdt.managedbuild.tool.gnu.assembler.base">
+								<inputType id="cdt.managedbuild.tool.gnu.assembler.input.285918871" superClass="cdt.managedbuild.tool.gnu.assembler.input"/>
+							</tool>
 						</toolChain>
 					</folderInfo>
 				</configuration>
@ -37,8 +46,15 @@
 	<storageModule moduleId="cdtBuildSystem" version="4.0.0">
 		<project id="mbus.null.914501471" name="mbus"/>
 	</storageModule>
+	<storageModule moduleId="org.eclipse.cdt.core.LanguageSettingsProviders"/>
+	<storageModule moduleId="refreshScope"/>
 	<storageModule moduleId="scannerConfiguration">
 		<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId=""/>
+		<scannerConfigBuildInfo instanceId="cdt.managedbuild.toolchain.gnu.base.1826992774;cdt.managedbuild.toolchain.gnu.base.1826992774.1618506567;cdt.managedbuild.tool.gnu.cpp.compiler.base.1875165406;cdt.managedbuild.tool.gnu.cpp.compiler.input.437218346">
+			<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId=""/>
+		</scannerConfigBuildInfo>
+		<scannerConfigBuildInfo instanceId="cdt.managedbuild.toolchain.gnu.base.1826992774;cdt.managedbuild.toolchain.gnu.base.1826992774.1618506567;cdt.managedbuild.tool.gnu.c.compiler.base.1454341581;cdt.managedbuild.tool.gnu.c.compiler.input.722267304">
+			<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId=""/>
+		</scannerConfigBuildInfo>
 	</storageModule>
-	<storageModule moduleId="org.eclipse.cdt.core.LanguageSettingsProviders"/>
 </cproject>
--- a/.gitignore
+++ b/.gitignore
@ -11,3 +11,4 @@ Makefile
 *.log
 *.in~
 systemd-units/mbusd@.service
+*.conf
--- a/Makefile.am
+++ b/Makefile.am
@ -4,13 +4,17 @@ ACLOCAL_AMFLAGS = -I m4

 SUBDIRS = src doc

-mbusddocdir = ${prefix}/doc/mbusd
+mbusddocdir = ${docdir}
 mbusddoc_DATA = \
 	README.md\
 	CHANGELOG.md\
 	LICENSE

-EXTRA_DIST = $(mbusddoc_DATA)
+mbusdconfdir = ${mbusddocdir}
+mbusdconf_DATA = \
+	conf/mbusd.conf.example
+
+EXTRA_DIST = $(mbusddoc_DATA) $(mbusdconf_DATA)

 # Copy all the spec files. Of cource, only one is actually used.
 dist-hook:
@ -34,4 +38,3 @@ $(systemdsystemunit_DATA):
 distclean-local::
 	-$(RM) $(systemdsystemunit_DATA)
 endif
-
--- a/Makefile.in
+++ b/Makefile.in
@ -158,9 +158,9 @@ am__uninstall_files_from_dir = { \
    || { echo " ( cd '$$dir' && rm -f" $$files ")"; \
         $(am__cd) "$$dir" && rm -f $$files; }; \
  }
-am__installdirs = "$(DESTDIR)$(mbusddocdir)" \
-	"$(DESTDIR)$(systemdsystemunitdir)"
-DATA = $(mbusddoc_DATA) $(systemdsystemunit_DATA)
+am__installdirs = "$(DESTDIR)$(mbusdconfdir)" \
+	"$(DESTDIR)$(mbusddocdir)" "$(DESTDIR)$(systemdsystemunitdir)"
+DATA = $(mbusdconf_DATA) $(mbusddoc_DATA) $(systemdsystemunit_DATA)
 RECURSIVE_CLEAN_TARGETS = mostlyclean-recursive clean-recursive	\
  distclean-recursive maintainer-clean-recursive
 am__recursive_targets = \
@ -367,13 +367,17 @@ top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 ACLOCAL_AMFLAGS = -I m4
 SUBDIRS = src doc
-mbusddocdir = ${prefix}/doc/mbusd
+mbusddocdir = ${docdir}
 mbusddoc_DATA = \
 	README.md\
 	CHANGELOG.md\
 	LICENSE

-EXTRA_DIST = $(mbusddoc_DATA)
+mbusdconfdir = ${mbusddocdir}
+mbusdconf_DATA = \
+	conf/mbusd.conf.example
+
+EXTRA_DIST = $(mbusddoc_DATA) $(mbusdconf_DATA)

 # systemd
 AM_DISTCHECK_CONFIGURE_FLAGS = \
@ -443,6 +447,27 @@ clean-libtool:

 distclean-libtool:
 	-rm -f libtool config.lt
+install-mbusdconfDATA: $(mbusdconf_DATA)
+	@$(NORMAL_INSTALL)
+	@list='$(mbusdconf_DATA)'; test -n "$(mbusdconfdir)" || list=; \
+	if test -n "$$list"; then \
+	  echo " $(MKDIR_P) '$(DESTDIR)$(mbusdconfdir)'"; \
+	  $(MKDIR_P) "$(DESTDIR)$(mbusdconfdir)" || exit 1; \
+	fi; \
+	for p in $$list; do \
+	  if test -f "$$p"; then d=; else d="$(srcdir)/"; fi; \
+	  echo "$$d$$p"; \
+	done | $(am__base_list) | \
+	while read files; do \
+	  echo " $(INSTALL_DATA) $$files '$(DESTDIR)$(mbusdconfdir)'"; \
+	  $(INSTALL_DATA) $$files "$(DESTDIR)$(mbusdconfdir)" || exit $$?; \
+	done
+
+uninstall-mbusdconfDATA:
+	@$(NORMAL_UNINSTALL)
+	@list='$(mbusdconf_DATA)'; test -n "$(mbusdconfdir)" || list=; \
+	files=`for p in $$list; do echo $$p; done | sed -e 's|^.*/||'`; \
+	dir='$(DESTDIR)$(mbusdconfdir)'; $(am__uninstall_files_from_dir)
 install-mbusddocDATA: $(mbusddoc_DATA)
 	@$(NORMAL_INSTALL)
 	@list='$(mbusddoc_DATA)'; test -n "$(mbusddocdir)" || list=; \
@ -788,7 +813,7 @@ check: check-recursive
 all-am: Makefile $(DATA) config.h
 installdirs: installdirs-recursive
 installdirs-am:
-	for dir in "$(DESTDIR)$(mbusddocdir)" "$(DESTDIR)$(systemdsystemunitdir)"; do \
+	for dir in "$(DESTDIR)$(mbusdconfdir)" "$(DESTDIR)$(mbusddocdir)" "$(DESTDIR)$(systemdsystemunitdir)"; do \
 	  test -z "$$dir" || $(MKDIR_P) "$$dir"; \
 	done
 install: install-recursive
@ -844,7 +869,8 @@ info: info-recursive

 info-am:

-install-data-am: install-mbusddocDATA install-systemdsystemunitDATA
+install-data-am: install-mbusdconfDATA install-mbusddocDATA \
+	install-systemdsystemunitDATA

 install-dvi: install-dvi-recursive

@ -890,7 +916,8 @@ ps: ps-recursive

 ps-am:

-uninstall-am: uninstall-mbusddocDATA uninstall-systemdsystemunitDATA
+uninstall-am: uninstall-mbusdconfDATA uninstall-mbusddocDATA \
+	uninstall-systemdsystemunitDATA

 .MAKE: $(am__recursive_targets) all install-am install-strip

@ -905,12 +932,13 @@ uninstall-am: uninstall-mbusddocDATA uninstall-systemdsystemunitDATA
 	install install-am install-data install-data-am install-dvi \
 	install-dvi-am install-exec install-exec-am install-html \
 	install-html-am install-info install-info-am install-man \
-	install-mbusddocDATA install-pdf install-pdf-am install-ps \
-	install-ps-am install-strip install-systemdsystemunitDATA \
-	installcheck installcheck-am installdirs installdirs-am \
-	maintainer-clean maintainer-clean-generic mostlyclean \
-	mostlyclean-generic mostlyclean-libtool pdf pdf-am ps ps-am \
-	tags tags-am uninstall uninstall-am uninstall-mbusddocDATA \
+	install-mbusdconfDATA install-mbusddocDATA install-pdf \
+	install-pdf-am install-ps install-ps-am install-strip \
+	install-systemdsystemunitDATA installcheck installcheck-am \
+	installdirs installdirs-am maintainer-clean \
+	maintainer-clean-generic mostlyclean mostlyclean-generic \
+	mostlyclean-libtool pdf pdf-am ps ps-am tags tags-am uninstall \
+	uninstall-am uninstall-mbusdconfDATA uninstall-mbusddocDATA \
 	uninstall-systemdsystemunitDATA

 .PRECIOUS: Makefile
--- a/README.md
+++ b/README.md
@ -47,20 +47,15 @@ Usage:

       -h     Usage help.
       -d     Instruct mbusd not to fork itself (non-daemonize).
-       -t     Enable RTS RS-485 data direction control (if not disabled while compile).
-       -y file
-              Enable RS-485 direction data direction control by writing '1' to file
-              for transmitter enable and '0' to file for transmitter disable
-       -Y file
-              Enable RS-485 direction data direction control by writing '0' to file
-              for transmitter enable and '1' to file for transmitter disable
+       -L logfile
+              Specifies log file name ('-' for logging to STDOUT only, default is /var/log/mbusd.log).
       -v level
              Specifies  log  verbosity level (0 for errors only, 1 for warnings
              and 2 for also information messages.) If mbusd was compiled in debug mode,
              valid log levels are up to 9, where log levels above 2 forces
              logging of information about additional internal events.
-       -L logfile
-              Specifies log file name ('-' for logging to STDOUT only, default is /var/log/mbusd.log).
+       -c cfgfile
+              Read configuration from cfgfile.
       -p device
              Specifies serial port device name.
       -s speed
@ -69,6 +64,13 @@ Usage:
              Specifies serial port mode (like 8N1).
       -P port
              Specifies TCP port number (default 502).
+       -t     Enable RTS RS-485 data direction control (if not disabled while compile).
+       -y file
+              Enable RS-485 direction data direction control by writing '1' to file
+              for transmitter enable and '0' to file for transmitter disable
+       -Y file
+              Enable RS-485 direction data direction control by writing '0' to file
+              for transmitter enable and '1' to file for transmitter disable
       -C maxconn
              Specifies maximum number of simultaneous TCP connections.
       -N retries
@ -82,16 +84,28 @@ Usage:

 Please note running **mbusd** on default Modbus TCP port (502) requires root privileges!

+Configuration file:
+-------------------
+**mbusd** can read the configuration from a file specified by `-c` command line flag.
+Please see [example configuration file](conf/mbusd.conf.example)
+for complete list of available configuration options.
+
 systemd:
 ---------------

-**mbusd** has [systemd](https://wiki.archlinux.org/index.php/systemd) support. The build system detects whether the system has systemd after which `sudo make install` installs the `mbusd@.service` file on systems with systemd active.
+**mbusd** has [systemd](https://wiki.archlinux.org/index.php/systemd) support.
+The build system detects whether the system has systemd after which `sudo make install`
+installs the `mbusd@.service` file on systems with systemd active.
+
 The **mbusd** service can be started via:

 	# systemctl start mbusd@<serial port>.service

 where `<serial port>` is serial port device name (like `ttyUSB0`).

+**mbusd** started by systemd will read its configuration from file named `/etc/mbusd/mbusd-<serial port>.conf`.
+This way it's possible to run multiple **mbusd** instances with different configurations.
+
 To see the **mbusd** service status:

 	# systemctl status mbusd@<serial port>.service
@ -106,12 +120,6 @@ To start the **mbusd** service on system boot:

 Please check systemd documentation for other usefull systemd [commands](https://wiki.archlinux.org/index.php/systemd)

-The checked in `mbusd@.service` starts **mbusd** equivalent to the following command:
-
-	# $PREFIX/bin/mbusd -p /dev/<serial port> -s 9600 -m 8N1 -P 502 -d -v2
-
-Feel free to modify the service file locally with your own desired configuration.
-
 Reporting bugs:
 ---------------

@ -119,7 +127,8 @@ Please file [issue](https://github.com/3cky/mbusd/issues) with attached debug lo

       # mbusd -L/tmp/mbusd.log -p /dev/ttyUSB0 -s 9600 -P 502 -d -v9

-Unless you were prompted so or there is another pertinent reason (e.g. GitHub fails to accept the bug report), please do not send bug reports via personal email.
+Unless you were prompted so or there is another pertinent reason (e.g. GitHub fails to accept the bug report),
+please do not send bug reports via personal email.

 Contributing:
 -------------
@ -146,6 +155,9 @@ Andrew Denysenko (<nitr0@seti.kr.ua>):
 James Jarvis (<jj@aprsworld.com>):
 - file based RS-485 data direction control

+Luuk Loeffen (<luukloeffen@hotmail.com>):
+ - systemd support
+
 License:
 --------

--- a/conf/mbusd.conf.example
+++ b/conf/mbusd.conf.example
@ -0,0 +1,44 @@
+#############################################
+#                                           #
+#    Sample configuration file for mbusd    #
+#                                           #
+#############################################
+
+########## Serial port settings #############
+
+# Serial port device name
+device = /dev/ttyS0
+
+# Serial port speed
+speed = 9600
+
+# Serial port mode
+mode = 8n1
+
+# RS-485 data direction control type (addc, rts, sysfs_0, sysfs_1)
+trx_control = addc
+
+# Sysfs file to use to control data direction
+# trx_sysfile =
+
+############# TCP port settings #############
+
+# TCP server port number
+port = 502
+
+# Maximum number of simultaneous TCP connections
+maxconn = 32
+
+# Connection timeout value in seconds
+timeout = 60
+
+######### Request/response settings #########
+
+# Maximum number of request retries
+retries = 3
+
+# Pause between requests in milliseconds
+pause = 100
+
+# Response wait time in milliseconds
+wait = 500
--- a/doc/mbusd.8.in
+++ b/doc/mbusd.8.in
@ -5,21 +5,23 @@ mbusd \- MODBUS/TCP to MODBUS/RTU gateway.
 .B mbusd
 .RB [ -h ]
 .RB [ -d ]
-.RB [ -t ]
-.RB [ -y
-.IR file ]
-.RB [ -Y
-.IR file ]
-.RB [ -v
-.IR level ]
 .RB [ -L
 .IR logfile ]
+.RB [ -v
+.IR level ]
+.RB [ -c
+.IR cfgfile ]
 .RB [ -p
 .IR device ]
 .RB [ -s
 .IR speed ]
 .RB [ -m
 .IR mode ]
+.RB [ -t ]
+.RB [ -y
+.IR file ]
+.RB [ -Y
+.IR file ]
 .RB [ -P
 .IR port ]
 .RB [ -C
@ -39,22 +41,16 @@ mbusd \- MODBUS/TCP to MODBUS/RTU gateway.
 Usage help.
 .IP \fB-d\fR
 Instruct \fImbusd\fR not to fork itself (non-daemonize).
-.IP \fB-t\fR
-Enable RTS RS-485 data direction control (if not disabled while compile).
-.IP "\fB-y \fIfile\fR"
-Enable RS-485 direction data direction control by writing '1' to file
-for transmitter enable and '0' to file for transmitter disable
-.IP "\fB-Y \fIfile\fR"
-Enable RS-485 direction data direction control by writing '0' to file
-for transmitter enable and '1' to file for transmitter disable
+.IP "\fB-L \fIlogfile\fR"
+Specifies log file name ('-' for logging to STDOUT only, default is /var/log/mbusd.log).
 .IP "\fB-v \fIlevel\fR"
 Specifies log verbosity level. 0 enables logging of errors only,
 1 also enables warnings and 2 enables information messages.
 If \fImbusd\fR was compiled in debug mode, valid log levels are up to 9,
 where log levels above 2 forces logging of information about additional
 internal events.
-.IP "\fB-L \fIlogfile\fR"
-Specifies log file name ('-' for logging to STDOUT only, default is /var/log/mbusd.log).
+.IP "\fB-c \fIcfgfile\fR"
+Read configuration from cfgfile.
 .IP "\fB-p \fIdevice\fR"
 Specifies serial port device name.
 .IP "\fB-s \fIspeed\fR"
@ -63,6 +59,14 @@ Specifies serial port speed.
 Specifies serial port mode (like 8N1).
 .IP "\fB-P \fIport\fR"
 Specifies TCP port number.
+.IP \fB-t\fR
+Enable RTS RS-485 data direction control (if not disabled while compile).
+.IP "\fB-y \fIfile\fR"
+Enable RS-485 direction data direction control by writing '1' to file
+for transmitter enable and '0' to file for transmitter disable
+.IP "\fB-Y \fIfile\fR"
+Enable RS-485 direction data direction control by writing '0' to file
+for transmitter enable and '1' to file for transmitter disable
 .IP "\fB-C \fImaxconn\fR"
 Specifies maximum number of simultaneous TCP connections.
 .IP "\fB-N \fIretries\fR"
--- a/src/cfg.c
+++ b/src/cfg.c
@ -33,9 +33,23 @@

 #include "cfg.h"

+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+
+#define CFG_MAX_LINE_LENGTH 200
+
+#define CFG_NAME_MATCH(n) strcmp(n, name) == 0
+#define CFG_VALUE_MATCH(n) strcasecmp(n, value) == 0
+
 /* Global configuration storage variable */
 cfg_t cfg;

+/* Configuration error message */
+char cfg_err[INTBUFSIZE + 1];
+
+#define CFG_ERR(s, v) snprintf(cfg_err, INTBUFSIZE, s, v)
+
 /*
 * Setting up config defaults
 */
@ -48,9 +62,10 @@ cfg_init(void)
 #endif
  strncpy(cfg.ttyport, DEFAULT_PORT, INTBUFSIZE);
  cfg.ttyspeed = DEFAULT_SPEED;
-  cfg.ttymode = DEFAULT_MODE;
-#ifdef  TRXCTL
+  strncpy(cfg.ttymode, DEFAULT_MODE, INTBUFSIZE);
+#ifdef TRXCTL
  cfg.trxcntl = TRX_ADDC;
+  *cfg.trxcntl_file = '\0';
 #endif
  cfg.serverport = DEFAULT_SERVERPORT;
  cfg.maxconn = DEFAULT_MAXCONN;
@ -60,3 +75,217 @@ cfg_init(void)
  cfg.resppause = DV(3, cfg.ttyspeed);
  cfg.conntimeout = DEFAULT_CONNTIMEOUT;
 }
+
+static char *
+cfg_rtrim(char *s)
+{
+  char *p = s + strlen(s);
+  while (p > s && isspace((unsigned char )(*--p)))
+    *p = '\0';
+  return s;
+}
+
+static char *
+cfg_ltrim(const char *s)
+{
+  while (*s && isspace((unsigned char )(*s)))
+    s++;
+  return (char *) s;
+}
+
+int
+cfg_handle_param(char *name, char *value)
+{
+  if (CFG_NAME_MATCH("device"))
+  {
+    strncpy(cfg.ttyport, value, INTBUFSIZE);
+  }
+  else if (CFG_NAME_MATCH("speed"))
+  {
+    cfg.ttyspeed = strtoul(value, NULL, 0);
+  }
+  else if (CFG_NAME_MATCH("mode"))
+  {
+    int mode_invalid;
+    if (strlen(value) != 3)
+      mode_invalid = 1;
+    else
+    {
+      char parity = toupper(value[1]);
+      mode_invalid = value[0] != '8' || (value[2] != '1' && value[2] != '2') ||
+          (parity != 'N' && parity != 'E' && parity != 'O');
+    }
+    if (mode_invalid)
+    {
+      CFG_ERR("invalid device mode: %s", value);
+      return 0;
+    }
+    strncpy(cfg.ttymode, value, INTBUFSIZE);
+  }
+  else if (CFG_NAME_MATCH("port"))
+  {
+    cfg.serverport = strtoul(value, NULL, 0);
+  }
+  else if (CFG_NAME_MATCH("maxconn"))
+  {
+    cfg.maxconn = strtoul(value, NULL, 0);
+    if (cfg.maxconn < 1 || cfg.maxconn > MAX_MAXCONN)
+    {
+      CFG_ERR("invalid maxconn value: %s", value);
+      return 0;
+    }
+  }
+  else if (CFG_NAME_MATCH("retries"))
+  {
+    cfg.maxtry = strtoul(value, NULL, 0);
+    if (cfg.maxtry > MAX_MAXTRY)
+    {
+      CFG_ERR("invalid retries value: %s", value);
+      return 0;
+    }
+  }
+  else if (CFG_NAME_MATCH("pause"))
+  {
+    cfg.rqstpause = strtoul(value, NULL, 0);
+    if (cfg.rqstpause < 1 || cfg.rqstpause > MAX_RQSTPAUSE)
+    {
+      CFG_ERR("invalid pause value: %s", value);
+      return 0;
+    }
+  }
+  else if (CFG_NAME_MATCH("wait"))
+  {
+    cfg.respwait = strtoul(value, NULL, 0);
+    if (cfg.respwait < 1 || cfg.respwait > MAX_RESPWAIT)
+    {
+      CFG_ERR("invalid wait value: %s", value);
+      return 0;
+    }
+  }
+  else if (CFG_NAME_MATCH("timeout"))
+  {
+    cfg.conntimeout = strtoul(value, NULL, 0);
+    if (cfg.conntimeout > MAX_CONNTIMEOUT)
+      return 0;
+#ifdef TRXCTL
+  }
+  else if (CFG_NAME_MATCH("trx_control"))
+  {
+    if (CFG_VALUE_MATCH("addc"))
+    {
+      cfg.trxcntl = TRX_ADDC;
+    }
+    else if (CFG_VALUE_MATCH("rts"))
+    {
+      cfg.trxcntl = TRX_RTS;
+    }
+    else if (CFG_VALUE_MATCH("sysfs_0"))
+    {
+      cfg.trxcntl = TRX_SYSFS_0;
+    }
+    else if (CFG_VALUE_MATCH("sysfs_1"))
+    {
+      cfg.trxcntl = TRX_SYSFS_1;
+    }
+    else
+    {
+      /* Unknown TRX control mode */
+      CFG_ERR("unknown trx control mode: %s", value);
+      return 0;
+    }
+  }
+  else if (CFG_NAME_MATCH("trx_sysfile"))
+  {
+    strncpy(cfg.trxcntl_file, value, INTBUFSIZE);
+#endif
+#ifdef LOG
+  }
+  else if (CFG_NAME_MATCH("loglevel"))
+  {
+    cfg.dbglvl = (char)strtol(optarg, NULL, 0);
+#endif
+  }
+  else {
+    /* Unknown parameter name */
+    CFG_ERR("unknown parameter: %s", name);
+    return 0;
+  }
+  return 1;
+}
+
+int
+cfg_parse_file(void *file)
+{
+  char *line;
+  char *start;
+  char *end;
+  char *name;
+  char *value;
+  int lineno = 0;
+  int error = 0;
+
+  *cfg_err = '\0';
+
+  line = (char *) malloc(CFG_MAX_LINE_LENGTH);
+  if (!line)
+  {
+    return -1;
+  }
+
+  while (fgets(line, CFG_MAX_LINE_LENGTH, file) != NULL)
+  {
+    lineno++;
+
+    start = cfg_ltrim(cfg_rtrim(line));
+
+    if (*start == '#')
+    {
+      /* skip comment */
+      continue;
+    }
+    else if (*start)
+    {
+      /* parse `name=value` pair */
+      for (end = start; *end && *end != '='; end++);
+      if (*end == '=')
+      {
+        *end = '\0';
+
+        name = cfg_rtrim(start);
+        value = cfg_ltrim(cfg_rtrim(end + 1));
+
+        /* handle name/value pair */
+        if (!cfg_handle_param(name, value))
+        {
+          error = lineno;
+          break;
+        }
+      }
+      else
+      {
+        /* no '=' found on config line */
+        error = lineno;
+        CFG_ERR("can't parse line: %s", start);
+        break;
+      }
+    }
+  }
+
+  free(line);
+
+  return error;
+}
+
+int
+cfg_read_file(const char *filename)
+{
+  FILE* file;
+  int error;
+
+  file = fopen(filename, "r");
+  if (!file)
+    return -1;
+  error = cfg_parse_file(file);
+  fclose(file);
+  return error;
+}
--- a/src/cfg.h
+++ b/src/cfg.h
@ -53,7 +53,7 @@ typedef struct
  /* tty speed */
  int ttyspeed;
  /* tty mode */
-  char *ttymode;
+  char ttymode[INTBUFSIZE + 1];
  /* trx control type (0 - ADDC, 1 - by RTS, 2 - by sysfs GPIO with 1 activating transmit, 3 - by sysfs GPIO with 0 activating transmit) */
  int trxcntl;
  /* trx control sysfs file */
@ -76,6 +76,8 @@ typedef struct

 /* Prototypes */
 extern cfg_t cfg;
+extern char cfg_err[];
 void cfg_init(void);
+int cfg_read_file(const char *filename);

 #endif /* _CFG_H */
--- a/src/conn.h
+++ b/src/conn.h
@ -53,6 +53,31 @@
 #define DEFAULT_RESPWAIT 500
 #define DEFAULT_CONNTIMEOUT 60

+/* Max simultaneous TCP connections to server */
+#ifndef MAX_MAXCONN
+#  define MAX_MAXCONN 128
+#endif
+
+/* Max RTU device request retries */
+#ifndef MAX_MAXTRY
+#  define MAX_MAXTRY 15
+#endif
+
+/* Max RTU device pause between requests, in msecs */
+#ifndef MAX_RQSTPAUSE
+#  define MAX_RQSTPAUSE 10000
+#endif
+
+/* Max RTU device response wait, in msecs */
+#ifndef MAX_RESPWAIT
+#  define MAX_RESPWAIT 10000
+#endif
+
+/* Max connection timeout, in secs */
+#ifndef MAX_CONNTIMEOUT
+#  define MAX_CONNTIMEOUT 1000
+#endif
+
 #define CRCSIZE 2       /* size (in bytes) of CRC */
 #define HDRSIZE 6       /* size (in bytes) of header */
 #define BUFSIZE 256     /* size (in bytes) of MODBUS data */
--- a/src/main.c
+++ b/src/main.c
@ -100,62 +100,70 @@ void
 usage(char *exename)
 {
  cfg_init();
-  printf("%s-%s Copyright (C) 2002-2003, 2011, 2013-2016 Victor Antonovich <v.antonovich@gmail.com>, "
+  printf("%s-%s Copyright (C) 2002-2003, 2011, 2013-2017 Victor Antonovich <v.antonovich@gmail.com>, "
   "Andrew Denysenko <nitr0@seti.kr.ua>\n\n"
   "Usage: %s [-h] [-d] "
-#ifdef TRXCTL
-   "[-t] [-y sysfsfile] [-Y sysfsfile]\n"
+#ifdef LOG
+   "[-L logfile] [-v level] "
 #endif
-   "[-v level] [-L logfile] [-p device] [-s speed] [-m mode] [-P port]\n"
-   "             [-C maxconn] [-N retries] [-R pause] [-W wait] [-T timeout]\n\n"
+   "[-c cfgfile] \n"
+   "             [-p device] [-s speed] [-m mode]\n"
+#ifdef TRXCTL
+   "             [-t] [-y sysfsfile] [-Y sysfsfile]\n"
+#endif
+   "             [-P port] [-C maxconn] [-N retries] [-R pause] [-W wait] [-T timeout]\n\n"
   "Options:\n"
   "  -h         : this help\n"
   "  -d         : don't daemonize\n"
-#ifdef TRXCTL
-   "  -t         : enable RTS RS-485 data direction control using RTS\n"
-   "  -y         : enable RTS RS-485 data direction control using sysfs file, active transmit\n"
-   "  -Y         : enable RTS RS-485 data direction control using sysfs file, active receive\n"
-#endif
 #ifdef LOG
+   "  -L logfile : set log file name (default %s%s, \n"
+   "               '-' for logging to STDOUT only)\n"
 #ifdef DEBUG
   "  -v level   : set log level (0-9, default %d, 0 - errors only)\n"
 #else
   "  -v level   : set log level (0-2, default %d, 0 - errors only)\n"
 #endif
-   "  -L logfile : set log file name (default %s%s, \n"
-   "               '-' for logging to STDOUT only)\n"
 #endif
+   "  -c cfgfile : read configuration from cfgfile\n"
   "  -p device  : set serial port device name (default %s)\n"
   "  -s speed   : set serial port speed (default %d)\n"
   "  -m mode    : set serial port mode (default %s)\n"
   "  -P port    : set TCP server port number (default %d)\n"
+#ifdef TRXCTL
+   "  -t         : enable RTS RS-485 data direction control using RTS\n"
+   "  -y         : enable RTS RS-485 data direction control using sysfs file, active transmit\n"
+   "  -Y         : enable RTS RS-485 data direction control using sysfs file, active receive\n"
+#endif
   "  -C maxconn : set maximum number of simultaneous TCP connections\n"
-   "               (1-128, default %d)\n"
+   "               (1-%d, default %d)\n"
   "  -N retries : set maximum number of request retries\n"
-   "               (0-15, default %d, 0 - without retries)\n"
+   "               (0-%d, default %d, 0 - without retries)\n"
   "  -R pause   : set pause between requests in milliseconds\n"
-   "               (1-10000, default %lu)\n"
+   "               (1-%d, default %lu)\n"
   "  -W wait    : set response wait time in milliseconds\n"
-   "               (1-10000, default %lu)\n"
+   "               (1-%d, default %lu)\n"
   "  -T timeout : set connection timeout value in seconds\n"
-   "               (0-1000, default %d, 0 - no timeout)"
+   "               (0-%d, default %d, 0 - no timeout)"
   "\n", PACKAGE, VERSION, exename,
 #ifdef LOG
-      cfg.dbglvl, LOGPATH, LOGNAME,
+      LOGPATH, LOGNAME, cfg.dbglvl,
 #endif
-      cfg.ttyport, cfg.ttyspeed, cfg.ttymode, cfg.serverport, cfg.maxconn,
-      cfg.maxtry, cfg.rqstpause, cfg.respwait, cfg.conntimeout);
+      cfg.ttyport, cfg.ttyspeed, cfg.ttymode, cfg.serverport,
+      MAX_MAXCONN, cfg.maxconn, MAX_MAXTRY, cfg.maxtry,
+      MAX_RQSTPAUSE, cfg.rqstpause, MAX_RESPWAIT, cfg.respwait,
+      MAX_CONNTIMEOUT, cfg.conntimeout);
  exit(0);
 }

 int
 main(int argc, char *argv[])
 {
-  int err = 0, rc;
+  int err = 0, rc, err_line;
  char *exename;
  char ttyparity;

  sig_init();
+
  cfg_init();

  if ((exename = strrchr(argv[0], '/')) == NULL)
@ -172,7 +180,7 @@ main(int argc, char *argv[])
 #ifdef LOG
               "v:L:"
 #endif
-               "p:s:m:P:C:N:R:W:T:")) != RC_ERR)
+               "p:s:m:P:C:N:R:W:T:c:")) != RC_ERR)
  {
    switch (rc)
    {
@ -181,16 +189,28 @@ main(int argc, char *argv[])
      case 'd':
        isdaemon = FALSE;
        break;
+      case 'c':
+        if ((err_line = cfg_read_file(optarg)) != 0)
+        {
+          if (err_line > 0)
+            printf("%s: can't read config file %s: error at line %d: %s\n",
+                   exename, optarg, err_line, cfg_err);
+          else
+            printf("%s: can't read config file %s: %s\n",
+                   exename, optarg, strerror(errno));
+          exit(-1);
+        }
+        break;
 #ifdef TRXCTL
      case 't':
        cfg.trxcntl = TRX_RTS;
        break;
      case 'y':
-	cfg.trxcntl = TRX_SYSFS_1;
+        cfg.trxcntl = TRX_SYSFS_1;
        strncpy(cfg.trxcntl_file, optarg, INTBUFSIZE);
 	break;
      case 'Y':
-	cfg.trxcntl = TRX_SYSFS_0;
+        cfg.trxcntl = TRX_SYSFS_0;
        strncpy(cfg.trxcntl_file, optarg, INTBUFSIZE);
 	break;
 #endif
@ -222,8 +242,7 @@ main(int argc, char *argv[])
          else
          { /* concatenate given log file name with default path */
            strncpy(cfg.logname, LOGPATH, INTBUFSIZE);
-            strncat(cfg.logname, optarg,
-                    INTBUFSIZE - strlen(cfg.logname));
+            strncat(cfg.logname, optarg, INTBUFSIZE - strlen(cfg.logname));
          }
        }
        else strncpy(cfg.logname, optarg, INTBUFSIZE);
@ -234,8 +253,7 @@ main(int argc, char *argv[])
        { /* concatenate given port name with default
             path to devices mountpoint */
          strncpy(cfg.ttyport, "/dev/", INTBUFSIZE);
-          strncat(cfg.ttyport, optarg,
-                  INTBUFSIZE - strlen(cfg.ttyport));
+          strncat(cfg.ttyport, optarg, INTBUFSIZE - strlen(cfg.ttyport));
        }
        else strncpy(cfg.ttyport, optarg, INTBUFSIZE);
        break;
@ -243,79 +261,80 @@ main(int argc, char *argv[])
        cfg.ttyspeed = strtoul(optarg, NULL, 0);
        break;
      case 'm':
-	cfg.ttymode = optarg;
-	/* tty mode sanity checks */
-	if (strlen(cfg.ttymode) != 3)
-	{
-	  printf("%s: -m: invalid serial port mode ('%s')\n", exename, cfg.ttymode);
-	  exit(-1);
-	}
-	if (cfg.ttymode[0] != '8')
-	{
-	  printf("%s: -m: invalid serial port character size "
-	      "(%c, must be 8)\n",
-	      exename, cfg.ttymode[0]);
-	  exit(-1);
-	}
-	ttyparity = toupper(cfg.ttymode[1]);
-	if (ttyparity != 'N' && ttyparity != 'E' && ttyparity != 'O')
-	{
-	  printf("%s: -m: invalid serial port parity "
-	      "(%c, must be N, E or O)\n", exename, ttyparity);
-	  exit(-1);
-	}
-	if (cfg.ttymode[2] != '1' && cfg.ttymode[2] != '2')
-	{
-	  printf("%s: -m: invalid serial port stop bits "
-	      "(%c, must be 1 or 2)\n", exename, cfg.ttymode[2]);
-	  exit(-1);
-	}
-	break;
+        strncpy(cfg.ttymode, optarg, INTBUFSIZE);
+        /* tty mode sanity checks */
+        if (strlen(cfg.ttymode) != 3)
+        {
+          printf("%s: -m: invalid serial port mode ('%s')\n",
+                 exename, cfg.ttymode);
+          exit(-1);
+        }
+        if (cfg.ttymode[0] != '8')
+        {
+          printf("%s: -m: invalid serial port character size "
+              "(%c, must be 8)\n",
+              exename, cfg.ttymode[0]);
+          exit(-1);
+        }
+        ttyparity = toupper(cfg.ttymode[1]);
+        if (ttyparity != 'N' && ttyparity != 'E' && ttyparity != 'O')
+        {
+          printf("%s: -m: invalid serial port parity "
+              "(%c, must be N, E or O)\n", exename, ttyparity);
+          exit(-1);
+        }
+        if (cfg.ttymode[2] != '1' && cfg.ttymode[2] != '2')
+        {
+          printf("%s: -m: invalid serial port stop bits "
+              "(%c, must be 1 or 2)\n", exename, cfg.ttymode[2]);
+          exit(-1);
+        }
+        break;
      case 'P':
        cfg.serverport = strtoul(optarg, NULL, 0);
        break;
      case 'C':
        cfg.maxconn = strtoul(optarg, NULL, 0);
-        if (cfg.maxconn < 1 || cfg.maxconn > 128)
+        if (cfg.maxconn < 1 || cfg.maxconn > MAX_MAXCONN)
        { /* report about invalid max conn number */
          printf("%s: -C: invalid maxconn value"
-                 " (%d, must be 1-128)\n", exename, cfg.maxconn);
+                 " (%d, must be 1-%d)\n", exename, cfg.maxconn, MAX_MAXCONN);
          exit(-1);
        }
        break;
      case 'N':
        cfg.maxtry = strtoul(optarg, NULL, 0);
-        if (cfg.maxtry > 15)
+        if (cfg.maxtry > MAX_MAXTRY)
        { /* report about invalid max try number */
          printf("%s: -N: invalid maxtry value"
-                 " (%d, must be 0-15)\n", exename, cfg.maxtry);
+                 " (%d, must be 0-%d)\n", exename, cfg.maxtry, MAX_MAXTRY);
          exit(-1);
        }
        break;
      case 'R':
        cfg.rqstpause = strtoul(optarg, NULL, 0);
-        if (cfg.rqstpause < 1 || cfg.rqstpause > 10000)
+        if (cfg.rqstpause < 1 || cfg.rqstpause > MAX_RQSTPAUSE)
        { /* report about invalid rqst pause value */
          printf("%s: -R: invalid inter-request pause value"
-                 " (%lu, must be 1-10000)\n", exename, cfg.rqstpause);
+                 " (%lu, must be 1-%d)\n", exename, cfg.rqstpause, MAX_RQSTPAUSE);
          exit(-1);
        }
        break;
      case 'W':
        cfg.respwait = strtoul(optarg, NULL, 0);
-        if (cfg.respwait < 1 || cfg.respwait > 10000)
+        if (cfg.respwait < 1 || cfg.respwait > MAX_RESPWAIT)
        { /* report about invalid resp wait value */
          printf("%s: -W: invalid response wait time value"
-                 " (%lu, must be 1-10000)\n", exename, cfg.respwait);
+                 " (%lu, must be 1-%d)\n", exename, cfg.respwait, MAX_RESPWAIT);
          exit(-1);
        }
        break;
      case 'T':
        cfg.conntimeout = strtoul(optarg, NULL, 0);
-        if (cfg.conntimeout > 1000)
+        if (cfg.conntimeout > MAX_CONNTIMEOUT)
        { /* report about invalid conn timeout value */
          printf("%s: -T: invalid conn timeout value"
-                 " (%d, must be 1-1000)\n", exename, cfg.conntimeout);
+                 " (%d, must be 1-%d)\n", exename, cfg.conntimeout, MAX_CONNTIMEOUT);
          exit(-1);
        }
        break;
--- a/systemd-units/mbusd@.service.in
+++ b/systemd-units/mbusd@.service.in
@ -3,7 +3,7 @@ Description=Modbus TCP to Modbus RTU (RS-232/485) gateway.
 Requires=network.target

 [Service]
-ExecStart=@bindir@/mbusd -p /dev/%i -s 9600 -m 8N1 -P 502 -d -v2
+ExecStart=@bindir@/mbusd -d -v2 -L - -c /etc/mbusd/mbusd-%i.conf -p /dev/%i
 Restart=on-failure
 RestartSec=1
 StandardOutput=journal