From 4b7ff505e46bb4d8c99fd548d4147f70014d228d Mon Sep 17 00:00:00 2001
From: bol-van <none@none.none>
Date: Mon, 16 Feb 2026 20:51:39 +0300
Subject: [PATCH] nfqws2: old kernels compat

---
 nfq2/darkmagic.c |  3 ++-
 nfq2/nfqws.c     | 18 +++++++++++++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/nfq2/darkmagic.c b/nfq2/darkmagic.c
index 0077b7d..10f650e 100644
--- a/nfq2/darkmagic.c
+++ b/nfq2/darkmagic.c
@@ -1880,8 +1880,9 @@ static int rawsend_socket(sa_family_t family)
 		}
 		if (family==AF_INET && setsockopt(*sock, IPPROTO_IP, IP_NODEFRAG, &yes, sizeof(yes)) == -1)
 		{
+			// since 2.6.36
 			DLOG_PERROR("rawsend: setsockopt(IP_NODEFRAG)");
-			goto exiterr;
+			//goto exiterr;
 		}
 		if (family==AF_INET && setsockopt(*sock, IPPROTO_IP, IP_FREEBIND, &yes, sizeof(yes)) == -1)
 		{
diff --git a/nfq2/nfqws.c b/nfq2/nfqws.c
index 146e60f..b6bc068 100644
--- a/nfq2/nfqws.c
+++ b/nfq2/nfqws.c
@@ -317,8 +317,14 @@ static bool nfq_init(struct nfq_handle **h, struct nfq_q_handle **qh, uint8_t *m
 		goto exiterr;
 	}
 
-	// linux kernels pass both ipv4 and ipv6 even if only AF_INET is boumd
 	// linux 3.8 - bind calls are NOOP.  linux 3.8- - secondary bind to AF_INET6 will fail
+	// old kernels seem to require both binds to ipv4 and ipv6. may not work without unbind
+
+	DLOG_CONDUP("unbinding existing nf_queue handler for AF_INET (if any)\n");
+	if (nfq_unbind_pf(*h, AF_INET) < 0) {
+		DLOG_PERROR("nfq_unbind_pf(AF_INET)");
+		goto exiterr;
+	}
 
 	DLOG_CONDUP("binding nfnetlink_queue as nf_queue handler for AF_INET\n");
 	if (nfq_bind_pf(*h, AF_INET) < 0) {
@@ -326,6 +332,16 @@ static bool nfq_init(struct nfq_handle **h, struct nfq_q_handle **qh, uint8_t *m
 		goto exiterr;
 	}
 
+	DLOG_CONDUP("unbinding existing nf_queue handler for AF_INET6 (if any)\n");
+	if (nfq_unbind_pf(*h, AF_INET6) < 0) {
+		DLOG_PERROR("nfq_unbind_pf(AF_INET6)");
+	}
+
+	DLOG_CONDUP("binding nfnetlink_queue as nf_queue handler for AF_INET6\n");
+	if (nfq_bind_pf(*h, AF_INET6) < 0) {
+		DLOG_PERROR("nfq_bind_pf(AF_INET6)");
+	}
+
 	DLOG_CONDUP("binding this socket to queue '%u'\n", params.qnum);
 	*qh = nfq_create_queue(*h, params.qnum, &nfq_cb, mod_buffer);
 	if (!*qh) {