Package Socket:

- fix tcp,udp,unix socket
- add socket unixgram for session less unix socket
- optmize process & code
- add some standalone test for server / client (add example server config for
  rsyslog)

Package Network/Protocol:
- add unixgram protocol

Package Errors:
- fix bug in loop to prevent circular include

socket/client/unixgram/model.go

@@ -0,0 +1,191 @@
+//go:build linux
+// +build linux
+
+/*
+ * MIT License
+ *
+ * Copyright (c) 2022 Nicolas JUHEL
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ *
+ */
+
+package unixgram
+
+import (
+	"bufio"
+	"context"
+	"errors"
+	"io"
+	"net"
+	"sync/atomic"
+
+	libptc "github.com/nabbar/golib/network/protocol"
+	libsck "github.com/nabbar/golib/socket"
+)
+
+type cli struct {
+	a *atomic.Value // address : unixfile
+	s *atomic.Int32 // buffer size
+	e *atomic.Value // function error
+	i *atomic.Value // function info
+}
+
+func (o *cli) RegisterFuncError(f libsck.FuncError) {
+	if o == nil {
+		return
+	}
+
+	o.e.Store(f)
+}
+
+func (o *cli) RegisterFuncInfo(f libsck.FuncInfo) {
+	if o == nil {
+		return
+	}
+
+	o.i.Store(f)
+}
+
+func (o *cli) fctError(e error) {
+	if o == nil {
+		return
+	}
+
+	v := o.e.Load()
+	if v != nil {
+		v.(libsck.FuncError)(e)
+	}
+}
+
+func (o *cli) fctInfo(local, remote net.Addr, state libsck.ConnState) {
+	if o == nil {
+		return
+	}
+
+	v := o.i.Load()
+	if v != nil {
+		v.(libsck.FuncInfo)(local, remote, state)
+	}
+}
+
+func (o *cli) buffSize() int {
+	v := o.s.Load()
+	if v > 0 {
+		return int(v)
+	}
+
+	return libsck.DefaultBufferSize
+}
+
+func (o *cli) dial(ctx context.Context) (net.Conn, error) {
+	if o == nil {
+		return nil, ErrInstance
+	}
+
+	v := o.a.Load()
+
+	if v == nil {
+		return nil, ErrAddress
+	} else if adr, ok := v.(string); !ok {
+		return nil, ErrAddress
+	} else {
+		d := net.Dialer{}
+		return d.DialContext(ctx, libptc.NetworkUnixGram.Code(), adr)
+	}
+}
+
+func (o *cli) Do(ctx context.Context, request io.Reader, fct libsck.Response) error {
+	if o == nil {
+		return ErrInstance
+	}
+
+	var (
+		err error
+		cnn net.Conn
+	)
+
+	defer func() {
+		if cnn != nil {
+			o.fctInfo(cnn.LocalAddr(), cnn.RemoteAddr(), libsck.ConnectionClose)
+			o.fctError(cnn.Close())
+		}
+	}()
+
+	o.fctInfo(&net.UnixAddr{}, &net.UnixAddr{}, libsck.ConnectionDial)
+	if cnn, err = o.dial(ctx); err != nil {
+		o.fctError(err)
+		return err
+	}
+
+	o.fctInfo(cnn.LocalAddr(), cnn.RemoteAddr(), libsck.ConnectionNew)
+
+	o.sendRequest(cnn, request)
+	o.readResponse(cnn, fct)
+
+	return nil
+}
+
+func (o *cli) sendRequest(con net.Conn, r io.Reader) {
+	var (
+		err error
+		buf []byte
+		rdr = bufio.NewReaderSize(r, o.buffSize())
+		wrt = bufio.NewWriterSize(con, o.buffSize())
+	)
+
+	for {
+		if con == nil && r == nil {
+			return
+		}
+
+		buf, err = rdr.ReadBytes('\n')
+
+		if err != nil {
+			if !errors.Is(err, io.EOF) {
+				o.fctError(err)
+			}
+			return
+		}
+
+		o.fctInfo(con.LocalAddr(), con.RemoteAddr(), libsck.ConnectionWrite)
+
+		_, err = wrt.Write(buf)
+		if err != nil {
+			o.fctError(err)
+			return
+		}
+
+		err = wrt.Flush()
+		if err != nil {
+			o.fctError(err)
+			return
+		}
+	}
+}
+
+func (o *cli) readResponse(con net.Conn, f libsck.Response) {
+	if f == nil {
+		return
+	}
+
+	o.fctInfo(con.LocalAddr(), con.RemoteAddr(), libsck.ConnectionHandler)
+	f(con)
+}