From 9481faded654975d4bc0539412fd925a278b51bd Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Mon, 26 Jul 2021 14:33:56 +0300
Subject: [PATCH] nncp-daemon's UCSPI-TCP compatibility

---
 doc/admin.texi              |  6 +++---
 doc/cfg/neigh.texi          |  2 +-
 doc/cmd/nncp-daemon.texi    | 21 ++++++++++++++-------
 doc/news.ru.texi            | 12 ++++++++++++
 doc/news.texi               | 11 +++++++++++
 src/cmd/nncp-daemon/main.go | 33 +++++++++++++++++++++++----------
 6 files changed, 64 insertions(+), 21 deletions(-)

diff --git a/doc/admin.texi b/doc/admin.texi
index a84c974..9a4c8e8 100644
--- a/doc/admin.texi
+++ b/doc/admin.texi
@@ -95,7 +95,7 @@ EOF
     @url{https://en.wikipedia.org/wiki/Inetd, inetd} service on UUCP's port:
 
 @example
-uucp	stream	tcp6	nowait	nncpuser	/usr/local/bin/nncp-daemon	nncp-daemon -quiet -inetd
+uucp	stream	tcp6	nowait	nncpuser	/usr/local/bin/nncp-daemon	nncp-daemon -quiet -ucspi
 @end example
 
 @item
@@ -108,8 +108,8 @@ uucp	stream	tcp6	nowait	nncpuser	/usr/local/bin/nncp-daemon	nncp-daemon -quiet -
 
 # cat > run <<EOF
 #!/bin/sh -e
-exec envuidgid nncpuser tcpserver -DHRU -l 0 0 uucp \
-	/usr/local/bin/nncp-daemon -quiet -inetd
+exec envuidgid nncpuser tcpserver -DHRU -l 0 ::0 uucp \
+	/usr/local/bin/nncp-daemon -quiet -ucspi
 EOF
 
 # cat > log/run <<EOF
diff --git a/doc/cfg/neigh.texi b/doc/cfg/neigh.texi
index ababdf9..fb2388d 100644
--- a/doc/cfg/neigh.texi
+++ b/doc/cfg/neigh.texi
@@ -27,7 +27,7 @@ neigh: {
     addrs: {
       lan: "[fe80::1234%igb0]:5400"
       internet: alice.com:3389
-      proxied: "|ssh remote.host nncp-daemon -inetd"
+      proxied: "|ssh remote.host nncp-daemon -ucspi"
     }
     calls: [
       {
diff --git a/doc/cmd/nncp-daemon.texi b/doc/cmd/nncp-daemon.texi
index aa11aca..4b5fa33 100644
--- a/doc/cmd/nncp-daemon.texi
+++ b/doc/cmd/nncp-daemon.texi
@@ -3,7 +3,7 @@
 
 @example
 $ nncp-daemon [options]
-    [-maxconn INT] [-bind ADDR] [-inetd]
+    [-maxconn INT] [-bind ADDR] [-ucspi]
     [-autotoss*] [-nock] [-mcd-once]
 @end example
 
@@ -16,14 +16,21 @@ time to time.
 can handle. @option{-bind} option specifies @option{addr:port} it must
 bind to and listen.
 
-It could be run as @command{inetd} service, by specifying
-@option{-inetd} option. Pay attention that because it uses
-@code{stdin}/@code{stdout}, it can not effectively work with IO timeouts
-and connection closing can propagate up to 5 minutes in practice.
-Example inetd-entry:
+It could be run as @url{http://cr.yp.to/ucspi-tcp.html, UCSPI-TCP}
+service, by specifying @option{-ucspi} option. Pay attention that
+because it uses @code{stdin}/@code{stdout}, it can not effectively work
+with IO timeouts and connection closing can propagate up to 5 minutes in
+practice. Example startup command:
 
 @verbatim
-uucp	stream	tcp6	nowait	nncpuser	/usr/local/bin/nncp-daemon	nncp-daemon -quiet -inetd
+tcpserver -DHR -l 0 ::0 uucp nncp-daemon -quiet -ucspi
+@end verbatim
+
+Also it is some kind of backward compatible with @command{inetd}
+interface, just lacking knowledge or remote's address:
+
+@verbatim
+uucp	stream	tcp6	nowait	nncpuser	/usr/local/bin/nncp-daemon	nncp-daemon -quiet -ucspi
 @end verbatim
 
 @option{-autotoss} option runs tosser on node's spool every second
diff --git a/doc/news.ru.texi b/doc/news.ru.texi
index 8d0bca9..25af628 100644
--- a/doc/news.ru.texi
+++ b/doc/news.ru.texi
@@ -1,6 +1,18 @@
 @node Новости
 @section Новости
 
+@node Релиз 7.5.0
+@subsection Релиз 7.5.0
+@itemize
+
+@item
+@command{nncp-daemon} соблюдает UCSPI-TCP интерфейс, благодаря чему в
+журнале будет присутствовать адрес удалённой системы (при запуске под
+совместимой утилитой). Желательно применять @option{-ucspi} опцию вместо
+@option{-inetd}.
+
+@end itemize
+
 @node Релиз 7.4.0
 @subsection Релиз 7.4.0
 @itemize
diff --git a/doc/news.texi b/doc/news.texi
index c9106f8..1d8a3ee 100644
--- a/doc/news.texi
+++ b/doc/news.texi
@@ -3,6 +3,17 @@
 
 See also this page @ref{Новости, on russian}.
 
+@node Release 7_5_0
+@section Release 7.5.0
+@itemize
+
+@item
+@command{nncp-daemon} is compatible with UCSPI-TCP interface, so log
+will contain remote side's address (when running under appropriate
+utility). @option{-ucspi} option should be used instead of @option{-inetd}.
+
+@end itemize
+
 @node Release 7_4_0
 @section Release 7.4.0
 @itemize
diff --git a/src/cmd/nncp-daemon/main.go b/src/cmd/nncp-daemon/main.go
index b0628fe..f27c2a3 100644
--- a/src/cmd/nncp-daemon/main.go
+++ b/src/cmd/nncp-daemon/main.go
@@ -40,28 +40,28 @@ func usage() {
 	flag.PrintDefaults()
 }
 
-type InetdConn struct {
+type UCSPIConn struct {
 	r *os.File
 	w *os.File
 }
 
-func (c InetdConn) Read(p []byte) (n int, err error) {
+func (c UCSPIConn) Read(p []byte) (n int, err error) {
 	return c.r.Read(p)
 }
 
-func (c InetdConn) Write(p []byte) (n int, err error) {
+func (c UCSPIConn) Write(p []byte) (n int, err error) {
 	return c.w.Write(p)
 }
 
-func (c InetdConn) SetReadDeadline(t time.Time) error {
+func (c UCSPIConn) SetReadDeadline(t time.Time) error {
 	return c.r.SetReadDeadline(t)
 }
 
-func (c InetdConn) SetWriteDeadline(t time.Time) error {
+func (c UCSPIConn) SetWriteDeadline(t time.Time) error {
 	return c.w.SetWriteDeadline(t)
 }
 
-func (c InetdConn) Close() error {
+func (c UCSPIConn) Close() error {
 	if err := c.r.Close(); err != nil {
 		c.w.Close() // #nosec G104
 		return err
@@ -138,7 +138,8 @@ func main() {
 		cfgPath   = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
 		niceRaw   = flag.String("nice", nncp.NicenessFmt(255), "Minimal required niceness")
 		bind      = flag.String("bind", "[::]:5400", "Address to bind to")
-		inetd     = flag.Bool("inetd", false, "Is it started as inetd service")
+		ucspi     = flag.Bool("ucspi", false, "Is it started as UCSPI-TCP server")
+		inetd     = flag.Bool("inetd", false, "Obsolete, use -ucspi")
 		maxConn   = flag.Int("maxconn", 128, "Maximal number of simultaneous connections")
 		noCK      = flag.Bool("nock", false, "Do no checksum checking")
 		mcdOnce   = flag.Bool("mcd-once", false, "Send MCDs once and quit")
@@ -174,6 +175,9 @@ func main() {
 	if err != nil {
 		log.Fatalln(err)
 	}
+	if *inetd {
+		*ucspi = true
+	}
 
 	ctx, err := nncp.CtxFromCmdline(
 		*cfgPath,
@@ -192,11 +196,20 @@ func main() {
 	}
 	ctx.Umask()
 
-	if *inetd {
+	if *ucspi {
 		os.Stderr.Close() // #nosec G104
-		conn := &InetdConn{os.Stdin, os.Stdout}
+		conn := &UCSPIConn{os.Stdin, os.Stdout}
 		nodeIdC := make(chan *nncp.NodeId)
-		go performSP(ctx, conn, "PIPE", nice, *noCK, nodeIdC)
+		addr := "PIPE"
+		if proto := os.Getenv("PROTO"); proto == "TCP" {
+			port := os.Getenv("TCPREMOTEPORT")
+			if host := os.Getenv("TCPREMOTEHOST"); host == "" {
+				addr = fmt.Sprintf("[%s]:%s", os.Getenv("TCPREMOTEIP"), port)
+			} else {
+				addr = fmt.Sprintf("%s:%s", host, port)
+			}
+		}
+		go performSP(ctx, conn, addr, nice, *noCK, nodeIdC)
 		nodeId := <-nodeIdC
 		var autoTossFinish chan struct{}
 		var autoTossBadCode chan bool
-- 
2.44.0