Explicitly shut down stdio's stdin/stdout/stderr.

The previous logic here was to only do this if stdio was connected to a controlling
terminal.  However, we must do this always to avoid information leaks and other
problems related to stdio.

The only exception is if we are in debug mode.

1 files changed, 29 insertions, 16 deletions

diff --git a/src/inspircd.cpp b/src/inspircd.cpp
index 86223ae95..1a856898f 100644
--- a/src/inspircd.cpp
+++ b/src/inspircd.cpp
@@ -595,23 +595,36 @@ InspIRCd::InspIRCd(int argc, char** argv) :
 		}
 	}
 
-	if (isatty(0) && isatty(1) && isatty(2))
+	/* Explicitly shut down stdio's stdin/stdout/stderr.
+	 *
+	 * The previous logic here was to only do this if stdio was connected to a controlling
+	 * terminal.  However, we must do this always to avoid information leaks and other
+	 * problems related to stdio.
+	 *
+	 * The only exception is if we are in debug mode.
+	 *
+	 *    -- nenolod
+	 */
+	if ((!do_nofork) && (!do_testsuite) && (!Config->cmdline.forcedebug))
 	{
-		/* We didn't start from a TTY, we must have started from a background process -
-		 * e.g. we are restarting, or being launched by cron. Dont kill parent, and dont
-		 * close stdin/stdout
-		 */
-		if ((!do_nofork) && (!do_testsuite))
-		{
-			fclose(stdin);
-			fclose(stderr);
-			if (!Config->cmdline.forcedebug)
-				fclose(stdout);
-		}
-		else
-		{
-			Logs->Log("STARTUP", DEFAULT,"Keeping pseudo-tty open as we are running in the foreground.");
-		}
+		int fd;
+
+		fclose(stdin);
+		fclose(stderr);
+		fclose(stdout);
+
+		fd = open("/dev/null", O_RDWR);
+		if (dup2(fd, 0) < 0)
+			Logs->Log("STARTUP", DEFAULT, "Failed to dup /dev/null to stdin.");
+		if (dup2(fd, 1) < 0)
+			Logs->Log("STARTUP", DEFAULT, "Failed to dup /dev/null to stdout.");
+		if (dup2(fd, 2) < 0)
+			Logs->Log("STARTUP", DEFAULT, "Failed to dup /dev/null to stderr.");
+		close(fd);
+	}
+	else
+	{
+		Logs->Log("STARTUP", DEFAULT,"Keeping pseudo-tty open as we are running in the foreground.");
 	}
 #else
 	WindowsIPC = new IPC;