From 1f7d6544e3a937b93a269f1d0f538fb6c64cba4d Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Thu, 17 Oct 2024 21:37:08 +0100
Subject: [PATCH] provide stdout to ppp callback scripts

pppd runs them with 0,1,2 => /dev/null but we actually quite like
seeing errors in the logs
---
 modules/ppp/common.nix | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/modules/ppp/common.nix b/modules/ppp/common.nix
index 65c3d6e..15d5492 100644
--- a/modules/ppp/common.nix
+++ b/modules/ppp/common.nix
@@ -15,25 +15,26 @@ let
   inherit (builtins) toJSON toString typeOf;
 
   ip-up = writeAshScript "ip-up" {} ''
+    exec >&5 2>&5
     . ${serviceFns} 
-    (in_outputs ${name}
-     echo $1 > ifname
-     echo $2 > tty
-     echo $3 > speed
-     echo $4 > address
-     echo $5 > peer-address
-     echo $DNS1 > ns1
-     echo $DNS2 > ns2
-    )
-    echo >/proc/self/fd/10
+    in_outputs ${name}
+    echo $1 > ifname
+    echo $2 > tty
+    echo $3 > speed
+    echo $4 > address
+    echo $5 > peer-address
+    set +o nounset
+    if test -n "''${DNS1}" ;then echo ''${DNS1} > ns1 ; fi
+    if test -n "''${DNS2}" ;then echo ''${DNS2} > ns2 ; fi
+    test -e ipv6-address && echo >/proc/self/fd/10
   '';
   ip6-up = writeAshScript "ip6-up" {} ''
+    exec >&5 2>&5
     . ${serviceFns} 
-    (in_outputs ${name}
-     echo $4 > ipv6-address
-     echo $5 > ipv6-peer-address
-    )
-    test -e tty && echo >/proc/self/fd/10
+    in_outputs ${name}
+    echo $4 > ipv6-address
+    echo $5 > ipv6-peer-address
+    test -e ifname && echo >/proc/self/fd/10
   '';
   literal_or_output =
     let v = o: ({
@@ -72,6 +73,7 @@ let
       chmod 0700 /run/${name}
       in_outputs ${name}
       echo ${escapeShellArgs ppp-options'} | ${output-template}/bin/output-template '{{' '}}' > /run/${name}/ppp-options
+      fdmove -c 5 2 \
       ${command}
     '';
     notification-fd = 10;