Fix anomalies in epmd not yet reported as security issues

Use erts_(v)snprintf to ensure no buffer overruns in debug printouts.
Disallow everything except port and name requests from remote nodes.
Disallow kill command even from localhost if alive nodes exist.
  -relaxed_command_check when starting epmd returns the possibility to
  kill this epmd when nodes are alive (from localhost).
Disallow stop command completely except if -relaxed_command_check is given
  when epmd was started.
Environment variable ERL_EPMD_RELAXED_COMMAND_CHECK can be set to always get
  -relaxed_command_check.

1 files changed, 6 insertions, 2 deletions

diff --git a/erts/epmd/src/epmd_int.h b/erts/epmd/src/epmd_int.h
index d69d8c93ef..c2558d52a1 100644
--- a/erts/epmd/src/epmd_int.h
+++ b/erts/epmd/src/epmd_int.h
@@ -246,8 +246,10 @@
 
 typedef struct {
   int fd;			/* File descriptor */
-  unsigned open:1;		/* TRUE if open */
-  unsigned keep:1;		/* Don't close when sent reply */
+  unsigned char open;		/* TRUE if open */
+  unsigned char keep;		/* Don't close when sent reply */
+  unsigned char local_peer;     /* The peer of this connection is via
+                                   loopback interface */
   unsigned got;			/* # of bytes we have got */
   unsigned want;		/* Number of bytes we want */
   char *buf;			/* The remaining buffer */
@@ -287,6 +289,7 @@ typedef struct {
   int debug;
   int silent; 
   int is_daemon;
+  int brutal_kill;
   unsigned packet_timeout;
   unsigned delay_accept;
   unsigned delay_write;
@@ -308,6 +311,7 @@ void epmd_call(EpmdVars*,int);
 void run(EpmdVars*);
 void epmd_cleanup_exit(EpmdVars*, int);
 int epmd_conn_close(EpmdVars*,Connection*);
+void stop_cli(EpmdVars *g, char *name);
 
 #ifdef DONT_USE_MAIN
 int  start_epmd(char *,char *,char *,char *,char *,char *,char *,char *,char *,char *);