From a7bc092eb93fb9526b27bca20ae7b88b01d99f84 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Wed, 26 Jan 2022 12:19:40 +0300
Subject: [PATCH] NNCPDEADLINE

---
 doc/news.ru.texi |  5 +++++
 doc/news.texi    |  5 +++++
 doc/sp.texi      |  5 +++++
 src/sp.go        | 10 ++++++++++
 4 files changed, 25 insertions(+)

diff --git a/doc/news.ru.texi b/doc/news.ru.texi
index 73d32cc..18a271f 100644
--- a/doc/news.ru.texi
+++ b/doc/news.ru.texi
@@ -12,6 +12,11 @@
 По ошибке @option{-mcd-wait} опция у @command{nncp-call} была включена
 по умолчанию.
 
+@item
+Возможность переопределять внутренний timeout по умолчанию для протокола
+синхронизации через @env{$NNCPDEADLINE} переменную окружения. Может быть
+полезно для каналов с очень большими задержками.
+
 @end itemize
 
 @node Релиз 8.4.0
diff --git a/doc/news.texi b/doc/news.texi
index 5b913b2..b52f514 100644
--- a/doc/news.texi
+++ b/doc/news.texi
@@ -14,6 +14,11 @@ Fixed @command{nncp-bundle} workability.
 Mistakenly @option{-mcd-wait} option was enabled by default in
 @command{nncp-call}.
 
+@item
+Ability to override internal default timeout for online protocol through
+@env{$NNCPDEADLINE} environment variable. Can be useful for very high
+delay links.
+
 @end itemize
 
 @node Release 8_4_0
diff --git a/doc/sp.texi b/doc/sp.texi
index 3944a75..e7f4895 100644
--- a/doc/sp.texi
+++ b/doc/sp.texi
@@ -12,6 +12,11 @@ high-delay links, so acknowledging of each received packet, like
 @url{https://en.wikipedia.org/wiki/XMODEM, XMODEM} does, causes
 unacceptable performance degradation.
 
+Internally it uses various timeouts and deadlines. One of them used
+extensively is 10 seconds default deadline timeout. You can override it
+with @env{$NNCPDEADLINE} environment variable, that could be useful with
+very high delay links.
+
 SP works on top of
 @url{http://noiseprotocol.org/noise.html#interactive-patterns,
 @code{Noise_IK_25519_ChaChaPoly_BLAKE2b}} protocol. Each Noise packet
diff --git a/src/sp.go b/src/sp.go
index 4db3587..e8e477c 100644
--- a/src/sp.go
+++ b/src/sp.go
@@ -27,6 +27,7 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"sync"
 	"time"
 
@@ -39,6 +40,7 @@ const (
 	MaxSPSize      = 1<<16 - 256
 	PartSuffix     = ".part"
 	SPHeadOverhead = 4
+	CfgDeadline    = "NNCPDEADLINE"
 )
 
 type MTHAndOffset struct {
@@ -132,6 +134,14 @@ type ConnDeadlined interface {
 }
 
 func init() {
+	if v := os.Getenv(CfgDeadline); v != "" {
+		i, err := strconv.Atoi(v)
+		if err != nil {
+			log.Fatalln("Can not convert", CfgDeadline, "to integer:", err)
+		}
+		DefaultDeadline = time.Duration(i) * time.Second
+	}
+
 	var buf bytes.Buffer
 	spHead := SPHead{Type: SPTypeHalt}
 	if _, err := xdr.Marshal(&buf, spHead); err != nil {
-- 
2.44.0