From f3a13630d30e3b4d9d84562782260de010c989fd Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Thu, 11 Apr 2024 23:03:49 +0100
Subject: [PATCH] add multicast groups param to nellie.open

---
 pkgs/nellie/nellie.c | 10 +++++++++-
 pkgs/nellie/test.lua |  2 +-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/pkgs/nellie/nellie.c b/pkgs/nellie/nellie.c
index 2267c51..69c3201 100644
--- a/pkgs/nellie/nellie.c
+++ b/pkgs/nellie/nellie.c
@@ -44,10 +44,18 @@ static int l_open_socket(lua_State *L) {
     memset(&sa, 0, sizeof(sa));
     sa.nl_family = AF_NETLINK;
     sa.nl_pid = getpid();
-    sa.nl_groups = 4; 		/* rebroadcasts from mdevd */
+
+    if(lua_isnumber(L, 1)) {
+	sa.nl_groups = lua_tointeger(L, 1);
+	lua_pop(L, 1);
+    }
+    else {
+	sa.nl_groups = 4; 		/* group 4 is rebroadcasts from mdevd */
+    }
 
     if(bind(netlink_fd, (struct sockaddr *) &sa, sizeof(sa))==0) {
 	lua_newtable(L);
+
 	lua_pushliteral(L, "fileno");
 	lua_pushinteger(L, netlink_fd);
 	lua_settable(L, 1);
diff --git a/pkgs/nellie/test.lua b/pkgs/nellie/test.lua
index f540d21..d964c49 100644
--- a/pkgs/nellie/test.lua
+++ b/pkgs/nellie/test.lua
@@ -1,5 +1,5 @@
 local nellie = require('nellie')
 print('dfg')
-local f = nellie.open()
+local f = nellie.open(2)
 
 print(string.byte(f:read(1000), 0, 60))