From 86d65b2c93696955e19f69b790f64019460d1ebb Mon Sep 17 00:00:00 2001
From: Tobias Ulmer <tu@emlix.com>
Date: Tue, 12 Feb 2019 19:24:28 +0100
Subject: [PATCH] le2lib: add functions to block and unblock signals

Signed-off-by: Tobias Ulmer <tu@emlix.com>
---
 generic/le2lib.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/generic/le2lib.c b/generic/le2lib.c
index bac7f73..b0d32e1 100644
--- a/generic/le2lib.c
+++ b/generic/le2lib.c
@@ -41,6 +41,8 @@
 
 static char buffer[PATH_MAX + 1];
 
+static sigset_t block_set;
+
 static int
 lua_fork(lua_State *lua)
 {
@@ -846,6 +848,12 @@ signal_install(lua_State *L)
 	/* Lua context for use in signal handler */
 	globalL = L;
 
+	/* Default signal blocking set while running a handler or
+	 * critical section */
+	sigemptyset(&block_set);
+	for (i = 0; signals[i] != 0; i++)
+		sigaddset(&block_set, signals[i]);
+
 	sa.sa_handler = signal_handler;
 	sa.sa_flags = 0;
 	sigemptyset(&sa.sa_mask);
@@ -885,6 +893,24 @@ signal_received(lua_State *L)
 	return 2;
 }
 
+static int
+signal_block(lua_State *lua)
+{
+	if (sigprocmask(SIG_BLOCK, &block_set, NULL) < 0)
+		return luaL_error(lua, "sigprocmask(SIG_BLOCK) failed: %s",
+		    strerror(errno));
+	return 0;
+}
+
+static int
+signal_unblock(lua_State *lua)
+{
+	if (sigprocmask(SIG_UNBLOCK, &block_set, NULL) < 0)
+		return luaL_error(lua, "sigprocmask(SIG_UNBLOCK) failed: %s",
+		    strerror(errno));
+	return 0;
+}
+
 static int
 do_forkpty(lua_State *L)
 {
@@ -928,9 +954,11 @@ static luaL_Reg lib[] = {
 	{ "rename", do_rename },
 	{ "rmdir", do_rmdir },
 	{ "setenv", do_setenv },
-	{ "signal_reset", signal_reset },
+	{ "signal_block", signal_block },
 	{ "signal_install", signal_install },
 	{ "signal_received", signal_received },
+	{ "signal_reset", signal_reset },
+	{ "signal_unblock", signal_unblock },
 	{ "stat", get_file_statistics },
 	{ "symlink", create_symlink },
 	{ "umask", set_umask },
-- 
2.39.5