[Pkg-privacy-commits] [msva-perl] 06/15: Make msva's primary listening daemon a subprocess instead of the parent

[Ximin Luo]

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infinity0 pushed a commit to annotated tag msva-perl_debian/0.8.1-2
in repository msva-perl.

commit a37ecdac8b63a41bf7e435feb6f5b6ce6ecbcdcf
Author: Daniel Kahn Gillmor <dkg at fifthhorseman.net>
Date:   Wed Jul 25 01:33:29 2012 -0400

    Make msva's primary listening daemon a subprocess instead of the parent
    
    A crashing MSVA should not kill the X11 session any longer.  This is
    modelled after OpenSSH's ssh-agent's behavior (though in contrast with
    ssh-agent's documentation).
---
 Crypt/Monkeysphere/MSVA.pm | 54 +++++++++++++++++++++++++---------------------
 Net/Server/MSVA.pm         |  6 ++++++
 2 files changed, 36 insertions(+), 24 deletions(-)

diff --git a/Crypt/Monkeysphere/MSVA.pm b/Crypt/Monkeysphere/MSVA.pm
index 2a8a2c7..34097f7 100755
--- a/Crypt/Monkeysphere/MSVA.pm
+++ b/Crypt/Monkeysphere/MSVA.pm
@@ -376,7 +376,7 @@
 
     # This is part of a spawned child process.  We don't want the
     # child process to destroy the update monitor when it terminates.
-    $self->{updatemonitor}->forget();
+    $self->{updatemonitor}->forget() if exists $self->{updatemonitor} && defined $self->{updatemonitor};
     my $clientinfo = get_client_info(select);
     my $clientuid = $clientinfo->{uid};
 
@@ -759,17 +759,22 @@
     my $self = shift;
     my $server = shift;
 
-    $self->spawn_master_subproc($server);
+    $self->spawn_as_child($server);
   }
 
-  sub master_subprocess_died {
+  sub pre_accept_hook {
     my $self = shift;
     my $server = shift;
-    my $subproc_return = shift;
 
-    my $exitstatus = POSIX::WEXITSTATUS($subproc_return);
-    msvalog('verbose', "Subprocess %d terminated; exiting %d.\n", $self->{child_pid}, $exitstatus);
-    $server->set_exit_status($exitstatus);
+    $self->parent_changed($server) if (getppid() != $self->{parent_pid});
+  }
+
+  sub parent_changed {
+    my $self = shift;
+    my $server = shift;
+
+    msvalog('verbose', "parent %d went away; exiting.\n", $self->{parent_pid});
+    $server->set_exit_status(0);
     $server->server_close();
   }
 
@@ -802,10 +807,6 @@
         # instead, we'll just avoid trying to kill the next process with this PID:
         $self->{updatemonitor}->forget();
       }
-    } elsif (exists $self->{child_pid} &&
-             ($self->{child_pid} == 0 ||
-              $self->{child_pid} == $pid)) {
-      $self->master_subprocess_died($server, $?);
     }
   }
 
@@ -848,20 +849,18 @@
       }
       $self->port($port);
     }
-    $self->port($port);
-    $self->{updatemonitor} = Crypt::Monkeysphere::MSVA::Monitor::->new($logger);
   }
 
-  sub spawn_master_subproc {
+  sub spawn_as_child {
     my $self = shift;
     my $server = shift;
 
-    if ((exists $ENV{MSVA_CHILD_PID}) && ($ENV{MSVA_CHILD_PID} ne '')) {
+    if ((exists $ENV{MSVA_PARENT_PID}) && ($ENV{MSVA_PARENT_PID} ne '')) {
       # this is most likely a re-exec.
-      msvalog('info', "This appears to be a re-exec, continuing with child pid %d\n", $ENV{MSVA_CHILD_PID});
-      $self->{child_pid} = $ENV{MSVA_CHILD_PID} + 0;
-    } elsif ($#ARGV >= 0) {
-      $self->{child_pid} = 0; # indicate that we are planning to fork.
+      msvalog('info', "This appears to be a re-exec, continuing with parent pid %d\n", $ENV{MSVA_PARENT_PID});
+      $self->{parent_pid} = $ENV{MSVA_PARENT_PID} + 0;
+     } elsif ($#ARGV >= 0) {
+      $self->{parent_pid} = 0; # indicate that we are planning to fork.
       # avoid ignoring SIGCHLD right before we fork.
       $SIG{CHLD} = sub {
         my $val;
@@ -869,20 +868,26 @@
           $self->child_dies($val, $server);
         }
       };
+      my $pid = $$;
       my $fork = fork();
       if (! defined $fork) {
         msvalog('error', "could not fork\n");
       } else {
-        if ($fork) {
-          msvalog('debug', "Child process has PID %d\n", $fork);
-          $self->{child_pid} = $fork;
-          $ENV{MSVA_CHILD_PID} = $fork;
+        if (! $fork) {
+          msvalog('debug', "daemon has PID %d, parent has PID %d\n", $$, $pid);
+          $self->{parent_pid} = $pid;
+          # ppid is set in Net::Server::Fork's post_configure; we're
+          # past post_configure by here, and we're about to change
+          # process IDs before assuming the role of a forking server,
+          # so we should set it properly:
+          $server->{server}->{ppid} = $$;
+          $ENV{MSVA_PARENT_PID} = $pid;
         } else {
           msvalog('verbose', "PID %d executing: \n", $$);
           for my $arg (@ARGV) {
             msvalog('verbose', " %s\n", $arg);
           }
-          # untaint the environment for the subprocess
+          # untaint the environment for the parent process
           # see: https://labs.riseup.net/code/issues/2461
           foreach my $e (keys %ENV) {
             $ENV{$e} = untaint($ENV{$e});
@@ -903,6 +908,7 @@
       # ssh-agent.  maybe avoid backgrounding by setting
       # MSVA_NO_BACKGROUND.
     };
+    $self->{updatemonitor} = Crypt::Monkeysphere::MSVA::Monitor::->new($logger);
   }
 
   sub extracerts {
diff --git a/Net/Server/MSVA.pm b/Net/Server/MSVA.pm
index 07e43ee..53b37ad 100644
--- a/Net/Server/MSVA.pm
+++ b/Net/Server/MSVA.pm
@@ -19,6 +19,7 @@
 { package Net::Server::MSVA;
   use strict;
   use base qw(Net::Server::Fork);
+  use Net::Server 2.000 ();
 
   my $msva;
   # guarantee initial failure -- this will be cleared after we bind
@@ -37,6 +38,11 @@
     $msva->pre_loop_hook($self, @_);
   }
 
+  sub pre_accept_hook {
+    my $self = shift;
+    $msva->pre_accept_hook($self, @_);
+  }
+
   sub set_exit_status {
     my $self = shift;
     $exit_status = shift;

-- 
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