From fff3e52f82222bbe68022becf3ee698b02af395c Mon Sep 17 00:00:00 2001
From: Antonio Ojea <aojea@redhat.com>
Date: Fri, 16 Jul 2021 12:28:57 +0200
Subject: [PATCH] bump rlimit so the eBPF map and program can be loaded

---
 README.md | 3 ++-
 nk.go     | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index d4fcd67..a0a247b 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,8 @@ netcat version using raw sockets to avoid iptables and/or other OS filtering mec
 ## Requirements
 
 It only works on Linux with a Kernel version > 5.2
-It requires CAP_NET_RAW privileges
+It requires CAP_NET_RAW and CAP_SYS_RESOURCE capabilities
+... or just run it with `sudo` ;)
 
 ## Install
 
diff --git a/nk.go b/nk.go
index 1a344d6..eb16456 100644
--- a/nk.go
+++ b/nk.go
@@ -110,6 +110,14 @@ func main() {
 		os.Exit(1)
 	}
 
+	// Increase rlimit so the eBPF map and program can be loaded.
+	if err := unix.Setrlimit(unix.RLIMIT_MEMLOCK, &unix.Rlimit{
+		Cur: unix.RLIM_INFINITY,
+		Max: unix.RLIM_INFINITY,
+	}); err != nil {
+		log.Fatalf("setting temporary rlimit: %s", err)
+	}
+
 	if !flagListen {
 		err = connect(ctx, args)
 		if err != nil {