From 2d7378dbc090eaf3b659de785a5b5669cddbe05e Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Mon, 16 Jan 2017 11:56:13 +0300
Subject: [PATCH] nncp-pkt can decompress the data

---
 doc/cmds.texi                                |  6 ++++--
 doc/news.texi                                |  1 +
 src/cypherpunks.ru/nncp/cmd/nncp-pkt/main.go | 21 +++++++++++++++-----
 3 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/doc/cmds.texi b/doc/cmds.texi
index 1061cc2..54348c8 100644
--- a/doc/cmds.texi
+++ b/doc/cmds.texi
@@ -185,7 +185,7 @@ operating system.
 
 @verbatim
 % nncp-pkt [options] < pkt
-% nncp-pkt [options] -dump < pkt > payload
+% nncp-pkt [options] [-decompress] -dump < pkt > payload
 @end verbatim
 
 Low level packet parser. Normally it should not be used, but can help in
@@ -215,7 +215,9 @@ Path: stargrave@stargrave.org
 @end verbatim
 
 And with the @option{-dump} option it will give you the actual payload
-(the whole file, mail message, and so on).
+(the whole file, mail message, and so on). @option{-decompress} option
+tries to zlib-decompress the data from plain packet (useful for mail
+packets).
 
 @node nncp-stat
 @section nncp-stat
diff --git a/doc/news.texi b/doc/news.texi
index 405cd15..d72250f 100644
--- a/doc/news.texi
+++ b/doc/news.texi
@@ -18,4 +18,5 @@ could be used to keep connection alive for a long time.
 @item @option{-maxonlinetime} option gives ability to set maximal
 allowable online connection alive time.
 @item @ref{nncp-caller} command appeared: cron-ed TCP daemon caller.
+@item @ref{nncp-pkt} command can decompress the data.
 @end itemize
diff --git a/src/cypherpunks.ru/nncp/cmd/nncp-pkt/main.go b/src/cypherpunks.ru/nncp/cmd/nncp-pkt/main.go
index 535c7d2..82bcffb 100644
--- a/src/cypherpunks.ru/nncp/cmd/nncp-pkt/main.go
+++ b/src/cypherpunks.ru/nncp/cmd/nncp-pkt/main.go
@@ -22,6 +22,7 @@ package main
 import (
 	"bufio"
 	"bytes"
+	"compress/zlib"
 	"flag"
 	"fmt"
 	"io"
@@ -44,10 +45,11 @@ func usage() {
 
 func main() {
 	var (
-		dump     = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
-		cfgPath  = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
-		version  = flag.Bool("version", false, "Print version information")
-		warranty = flag.Bool("warranty", false, "Print warranty information")
+		dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
+		decompress = flag.Bool("decompress", false, "Try to zlib decompress dumped data")
+		cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
+		version    = flag.Bool("version", false, "Print version information")
+		warranty   = flag.Bool("warranty", false, "Print warranty information")
 	)
 	flag.Usage = usage
 	flag.Parse()
@@ -70,7 +72,16 @@ func main() {
 	if err == nil && pkt.Magic == nncp.MagicNNCPPv1 {
 		if *dump {
 			bufW := bufio.NewWriter(os.Stdout)
-			if _, err = io.Copy(bufW, bufio.NewReader(os.Stdin)); err != nil {
+			var r io.Reader
+			r = bufio.NewReader(os.Stdin)
+			if *decompress {
+				decompressor, err := zlib.NewReader(r)
+				if err != nil {
+					log.Fatalln(err)
+				}
+				r = decompressor
+			}
+			if _, err = io.Copy(bufW, r); err != nil {
 				log.Fatalln(err)
 			}
 			if err = bufW.Flush(); err != nil {
-- 
2.44.0