Merge pull request #448 from appneta/Enhancement_#416_non-blocking_STDIN

Enhancement #416 non blocking stdin

docs/CHANGELOG

@@ -2,6 +2,7 @@
     - Travis CI build fails due to new build images (#432)
     - Unable to build with libpcap 1.8.1 (#430)
     - Unable to tcprewrite range of ports with --portmap (#422)
+    - Avoid non-blocking behaviour when using STDIN (#416)
     - pcap containing >1020 packets produces invalid cache file (#415)
     - heap-buffer-overflow in get_l2protocol (#410)
     - heap-buffer-overflow in packet2tree (#409)

src/common/utils.c

@@ -28,6 +28,10 @@
 #include <ctype.h>
 #include <unistd.h>
 
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
 #ifdef DEBUG
 extern int debug;
 #endif
@@ -335,3 +339,21 @@ int tcpr_random(uint32_t *seed)
 
   return result;
 }
+
+/**
+ * #416 - Ensure STDIN is not left in non-blocking mode after closing
+ * a program. BSD and Unix derivatives should utilize `FIONBIO` due to known
+ * issues with reading from tty with a 0 byte read returning -1 opposed to 0.
+ */
+void restore_stdin(void)
+{
+#ifdef FIONBIO
+    int nb = 0;
+
+    ioctl(0, FIONBIO, &nb);
+#else
+    fcntl(0, F_SETFL, fcntl(0, F_GETFL) | O_NONBLOCK);
+#endif /* FIONBIO */
+
+
+}

src/common/utils.h

@@ -48,6 +48,7 @@ int read_hexstring(const char *l2string, u_char *hex, const int hexlen);
 void packet_stats(const tcpreplay_stats_t *stats);
 int format_date_time(struct timeval *when, char *buf, size_t len);
 int tcpr_random(uint32_t *seed);
+void restore_stdin(void);
 
 /* our "safe" implimentations of functions which allocate memory */
 #define safe_malloc(x) _our_safe_malloc(x, __FUNCTION__, __LINE__, __FILE__)

src/tcpbridge.c

@@ -114,6 +114,7 @@ main(int argc, char *argv[])
     tcpdump_close(options.tcpdump);
 #endif
 
+    restore_stdin();
     return 0;
 }
 

src/tcpcapinfo.c

@@ -332,13 +332,11 @@ main(int argc, char *argv[])
             } else if (backwards && caplentoobig) {
                 printf("BAD_TS|TOOBIG");
             } 
-
         }
-
     }
 
-    exit(0);
-
+    restore_stdin();
+    return 0;
 }
 
 /**

src/tcpliveplay.c

@@ -383,6 +383,7 @@ main(int argc, char **argv)
     printf("----------------------------------------------------------\n\n");
 
     free(sched);
+    restore_stdin();
     return 0;
 } 
 /*end of main() function*/

src/tcpprep.c

@@ -193,8 +193,9 @@ main(int argc, char *argv[])
 
     /* close cache file */
     close(out_file);
-    return 0;
 
+    restore_stdin();
+    return 0;
 }
 
 

src/tcpreplay.c

@@ -157,6 +157,7 @@ main(int argc, char *argv[])
         }
     }
     tcpreplay_close(ctx);
+    restore_stdin();
     return 0;
 }   /* main() */
 

src/tcprewrite.c

@@ -149,6 +149,8 @@ main(int argc, char *argv[])
 #ifdef ENABLE_DMALLOC
     dmalloc_shutdown();
 #endif
+
+    restore_stdin();
     return 0;
 }