Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdelibs@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 172 insertions, 0 deletions

diff --git a/kinit/start_kdeinit.c b/kinit/start_kdeinit.c
new file mode 100644
index 000000000..722f3e97f
--- /dev/null
+++ b/kinit/start_kdeinit.c
@@ -0,0 +1,172 @@
+/*
+ * This file is part of the KDE libraries
+ * Copyright (c) 2006 Lubos Lunak <l.lunak@kde.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License version 2 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <config.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifdef KDEINIT_OOM_PROTECT
+
+/*
+ Prevent getting killed by bad heuristic in Linux OOM-killer.
+ This wrapper decreases the chance OOM killer kills it (or its children,
+ namely kdeinit), opens a pipe and forks. Child drops privileges
+ and launches kdeinit. Since processes started by kdeinit should
+ not have this protection, kdeinit will after forking send the new
+ PID using the pipe and wait for a signal. This parent will reset the protection
+ and SIGUSR1 the process to continue.
+ returns 1 if pid is valid
+*/
+
+static int set_protection( pid_t pid, int enable )
+{
+   char buf[ 1024 ];
+   int procfile;
+   sprintf( buf, "/proc/%d/stat", pid );
+   if( !enable ) {
+       /* Be paranoid and check that the pid we got from the pipe
+          belongs to this user. */
+       struct stat st;
+       if( lstat( buf, &st ) < 0 || st.st_uid != getuid())
+           return 0;
+   }
+   sprintf( buf, "/proc/%d/oom_adj", pid );
+   procfile = open( buf, O_WRONLY );
+   if( procfile >= 0 ) {
+      if( enable )
+         write( procfile, "-5", sizeof( "-5" ));
+      else
+         write( procfile, "0", sizeof( "0" ));
+      close( procfile );
+   }
+   return 1;
+}
+
+int main(int argc, char **argv)
+{
+   int pipes[ 2 ];
+   int new_argc;
+   const char** new_argv;
+   char helper_num[ 1024 ];
+   unsigned i;
+   char** orig_environ = NULL;
+   char header[ 7 ];
+   if( pipe( pipes ) < 0 ) {
+      perror( "pipe()" );
+      return 1;
+   }
+   if( argc < 0 || argc > 1000 )
+       abort(); /* paranoid */
+   set_protection( getpid(), 1 );
+   switch( fork()) {
+      case -1:
+         perror( "fork()" );
+         return 1;
+      default: /* parent, drop privileges and exec */
+         if (setgid(getgid())) {
+             perror("setgid()");
+             return 1;
+         }
+         if (setuid(getuid()) || geteuid() != getuid()) {
+            perror("setuid()");
+            return 1;
+         }
+         close( pipes[ 0 ] );
+         /* read original environment passed by start_kdeinit_wrapper */
+         if( read( 0, header, 7 ) == 7 && strncmp( header, "environ", 7 ) == 0 ) {
+             unsigned count;
+             if( read( 0, &count, sizeof( unsigned )) == sizeof( unsigned )
+                 && count && count < (1<<16)) {
+                 char** env = malloc(( count + 1 ) * sizeof( char* ));
+                 int ok = 1;
+                 for( i = 0;
+                      i < count && ok;
+                      ++i ) {
+                     unsigned len;
+                     if( read( 0, &len, sizeof( unsigned )) == sizeof( unsigned )
+                         && len && len < (1<<12)) {
+                         env[ i ] = malloc( len + 1 );
+                         if( (unsigned) read( 0, env[ i ], len ) == len ) {
+                             env[ i ][ len ] = '\0';
+                         } else {
+                             ok = 0;
+                         }
+                     }
+                 }
+                 if( ok ) {
+                   env[ i ] = NULL;
+                   orig_environ = env;
+                 }
+             }
+         }
+         if(argc == 0)
+            return 1;
+         new_argc = argc + 2;
+         new_argv = malloc( sizeof( char* ) * ( new_argc + 1 ));
+         if( new_argv == NULL )
+            return 1;
+         new_argv[ 0 ] = EXECUTE;
+         new_argv[ 1 ] = "--oom-pipe";
+         sprintf( helper_num, "%d", pipes[ 1 ] );
+         new_argv[ 2 ] = helper_num;
+         for( i = 1;
+              i <= (unsigned) argc;
+              ++i )
+             new_argv[ i + 2 ] = argv[ i ];
+         if( orig_environ )
+             execve(EXECUTE, (char**)new_argv, orig_environ);
+         else
+             execv(EXECUTE, (char**)new_argv);
+         perror(EXECUTE);
+         return 1;
+      case 0: /* child, keep privileges and do the privileged work */
+         close( pipes[ 1 ] );
+         for(;;) {
+            pid_t pid = 0;
+            int ret = read( pipes[ 0 ], &pid, sizeof( pid_t ));
+            if( ret < 0 && errno == EINTR )
+               continue;
+            if( ret <= 0 ) /* pipe closed or error, exit */
+               _exit(0);
+            if( pid != 0 ) {
+                if (set_protection( pid, 0 ))
+                    kill( pid, SIGUSR1 );
+            }
+         }
+   }
+}
+
+#else /* not Linux, the simple non-setuid case */
+
+int main(int argc, char **argv)
+{
+   if(argc == 0)
+      return 1;
+   argv[0] = (char*)EXECUTE;
+   execv(EXECUTE,argv);
+   perror(EXECUTE);
+   return 1;
+}
+#endif