From 2b331a082bb710d1e5a529ed32dcbba0a2e843cb Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Sun, 8 Aug 2021 11:00:32 +0300
Subject: [PATCH] Logging to opened file descriptor

---
 doc/admin.texi       |  9 +++++----
 doc/cfg/general.texi |  7 ++++++-
 doc/log.texi         | 25 +++++++++++++++++++++++++
 doc/news.ru.texi     | 11 +++++++++++
 doc/news.texi        | 11 +++++++++++
 ports/nncp/Makefile  |  2 +-
 src/ctx.go           | 14 ++++++++++++++
 src/log.go           |  8 ++++++++
 src/nncp.go          |  2 +-
 9 files changed, 82 insertions(+), 7 deletions(-)

diff --git a/doc/admin.texi b/doc/admin.texi
index 9a4c8e8..86caeb9 100644
--- a/doc/admin.texi
+++ b/doc/admin.texi
@@ -100,7 +100,8 @@ uucp	stream	tcp6	nowait	nncpuser	/usr/local/bin/nncp-daemon	nncp-daemon -quiet -
 
 @item
     Or it can be also run as a @command{daemontools} daemon under
-    @url{http://cr.yp.to/ucspi-tcp.html, UCSPI-TCP}:
+    @url{http://cr.yp.to/ucspi-tcp.html, UCSPI-TCP}. In the example
+    below it uses native daemontools's logging capability:
 
 @example
 # mkdir -p /var/service/.nncp-daemon/log
@@ -108,13 +109,13 @@ 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 -ucspi
+NNCPLOG=FD:4 exec envuidgid nncpuser tcpserver -DHRU -l 0 ::0 uucp \
+	/usr/local/bin/nncp-daemon -quiet -ucspi 4>&1
 EOF
 
 # cat > log/run <<EOF
 #!/bin/sh -e
-exec setuidgid uucp multilog t ./main
+exec setuidgid uucp multilog ./main
 EOF
 
 # chmod -R 755 /var/service/.nncp-daemon
diff --git a/doc/cfg/general.texi b/doc/cfg/general.texi
index 63d0757..971b585 100644
--- a/doc/cfg/general.texi
+++ b/doc/cfg/general.texi
@@ -21,7 +21,12 @@ mcd-send: {em0: 60, igb1: 5}
 @item spool
 Absolute path to the @ref{Spool, spool} directory.
 @item log
-Absolute path to the @ref{Log, log} file.
+Either:
+    @itemize
+    @item absolute path to the @ref{Log, log} file
+    @item @code{FD:XXX}, where @code{XXX} is a decimal file descriptor
+        to write records too
+    @end itemize
 @item umask
 Will force all invoked commands to override their umask to specified
 octal mask. Useful for using with @ref{Shared spool, shared spool directories}.
diff --git a/doc/log.texi b/doc/log.texi
index 3c91f61..74a8c6d 100644
--- a/doc/log.texi
+++ b/doc/log.texi
@@ -6,3 +6,28 @@ Log is a plaintext file consisting of
 read by human, but it is better to use either @ref{nncp-log}, or
 @command{recutils} utilities for selecting and formatting the required
 fields.
+
+Two example records from it:
+
+@verbatim
+When: 2021-08-07T20:30:49.042460622Z
+Who: sp-file-done
+Node: BYRRQUULEHINPKEFN7CHMSHR5I5CK7PMX5HQNCYERTBAR4BOCG6Q
+Nice: 255
+Type: file
+XX: rx
+Pkt: VQFR6KXC5N4UGL3HKKJKPXE4TN3G4UQGFXQTEYFZ7ZZIKWUVKOGA
+Size: 5229
+FullSize: 5229
+Msg: Got packet VQFR6KXC5N4UGL3HKKJKPXE4TN3G4UQGFXQTEYFZ7ZZIKWUVKOGA 100% (5.1 KiB / 5.1 KiB): done
+
+When: 2021-08-07T20:30:49.131766306Z
+Who: rx
+Node: BYRRQUULEHINPKEFN7CHMSHR5I5CK7PMX5HQNCYERTBAR4BOCG6Q
+Pkt: VQFR6KXC5N4UGL3HKKJKPXE4TN3G4UQGFXQTEYFZ7ZZIKWUVKOGA
+Nice: 96
+Size: 4741
+Type: exec
+Dst: sendmail stargrave@stargrave.org
+Msg: Got exec from gw to sendmail stargrave@stargrave.org (4.6 KiB)
+@end verbatim
diff --git a/doc/news.ru.texi b/doc/news.ru.texi
index 8218c80..d2c5f83 100644
--- a/doc/news.ru.texi
+++ b/doc/news.ru.texi
@@ -1,6 +1,17 @@
 @node Новости
 @section Новости
 
+@node Релиз 7.6.0
+@subsection Релиз 7.6.0
+@itemize
+
+@item
+Журналирование может производиться в назначенный открытый файловый
+дескриптор (@env{$NNCPLOG=FD:5} например).
+Что дружелюбно к использованию под @command{daemontools}.
+
+@end itemize
+
 @node Релиз 7.5.1
 @subsection Релиз 7.5.1
 @itemize
diff --git a/doc/news.texi b/doc/news.texi
index 85c7acd..48f5ec0 100644
--- a/doc/news.texi
+++ b/doc/news.texi
@@ -3,6 +3,17 @@
 
 See also this page @ref{Новости, on russian}.
 
+@node Release 7_6_0
+@section Release 7.6.0
+@itemize
+
+@item
+Logging may be done to specified opened file descriptor
+(@env{$NNCPLOG=FD:5} for example).
+That is friendly to use under @command{daemontools}.
+
+@end itemize
+
 @node Release 7_5_1
 @section Release 7.5.1
 @itemize
diff --git a/ports/nncp/Makefile b/ports/nncp/Makefile
index 70b6311..6ff741a 100644
--- a/ports/nncp/Makefile
+++ b/ports/nncp/Makefile
@@ -1,5 +1,5 @@
 PORTNAME=	nncp
-DISTVERSION=	7.4.0
+DISTVERSION=	7.6.0
 CATEGORIES=	net
 MASTER_SITES=	http://www.nncpgo.org/download/
 
diff --git a/src/ctx.go b/src/ctx.go
index 7e4d726..58dba44 100644
--- a/src/ctx.go
+++ b/src/ctx.go
@@ -23,6 +23,8 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strconv"
+	"strings"
 
 	"syscall"
 )
@@ -135,6 +137,18 @@ func CtxFromCmdline(
 	} else {
 		ctx.LogPath = logPath
 	}
+	if strings.HasPrefix(ctx.LogPath, LogFdPrefix) {
+		ptr, err := strconv.ParseUint(
+			strings.TrimPrefix(ctx.LogPath, LogFdPrefix), 10, 64,
+		)
+		if err != nil {
+			return nil, err
+		}
+		LogFd = os.NewFile(uintptr(ptr), CfgLogEnv)
+		if LogFd == nil {
+			return nil, errors.New("can not open:" + ctx.LogPath)
+		}
+	}
 	if showPrgrs {
 		ctx.ShowPrgrs = true
 	}
diff --git a/src/log.go b/src/log.go
index 7bb59a3..9a8d2e7 100644
--- a/src/log.go
+++ b/src/log.go
@@ -27,6 +27,10 @@ import (
 	"golang.org/x/sys/unix"
 )
 
+const LogFdPrefix = "FD:"
+
+var LogFd *os.File
+
 type LE struct {
 	K string
 	V interface{}
@@ -64,6 +68,10 @@ func (les LEs) Rec() string {
 }
 
 func (ctx *Ctx) Log(rec string) {
+	if LogFd != nil {
+		LogFd.WriteString(rec)
+		return
+	}
 	fdLock, err := os.OpenFile(
 		ctx.LogPath+".lock",
 		os.O_CREATE|os.O_WRONLY,
diff --git a/src/nncp.go b/src/nncp.go
index 8e04f04..c641668 100644
--- a/src/nncp.go
+++ b/src/nncp.go
@@ -40,7 +40,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.`
 const Base32Encoded32Len = 52
 
 var (
-	Version string = "7.5.1"
+	Version string = "7.6.0"
 
 	Base32Codec *base32.Encoding = base32.StdEncoding.WithPadding(base32.NoPadding)
 )
-- 
2.44.0