From: Davin McCall <davmac@davmac.org>
Date: Thu, 10 Nov 2016 02:34:32 +0000 (+0000)
Subject: Run not-on-console services in a session (via setsid()).
X-Git-Tag: v0.05~10
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=a8f03b17e4f0dce8961227a7e2cfc970c9e54b7c;p=oweals%2Fdinit.git

Run not-on-console services in a session (via setsid()).

This prevents them from receiving terminal control signals, if
dinit is running on a terminal (normally only if run in user
mode).
---

diff --git a/src/service.cc b/src/service.cc
index 4a5bcec..a8ea823 100644
--- a/src/service.cc
+++ b/src/service.cc
@@ -875,10 +875,23 @@ void ServiceRecord::run_child_proc(const char * const *args, const char *logfile
             }
         }
         else goto failure_out;
+        
+        // We have the option of creating a new process group and/or session. If
+        // we just create a new process group, the child process cannot make itself
+        // a session leader if it wants to do that (eg getty/login will generally
+        // want this). If we do neither, and we are running with a controlling
+        // terminal, a ^C or similar will also affect the child process.
+        setsid();
     }
     else {
         // "run on console" - run as a foreground job on the terminal/console device
         
+        // if do_set_ctty is false, we are the session leader; we are probably running
+        // as a user process. Don't create a new session leader in that case, and run
+        // as part of the parent session. Otherwise, the new session cannot claim the
+        // terminal as a controlling terminal (it is already claimed), meaning that it
+        // will not see control signals from ^C etc.
+        
         if (do_set_ctty) {
             // Disable suspend (^Z) (and on some systems, delayed suspend / ^Y)
             signal(SIGTSTP, SIG_IGN);