[PATCH libnetfilter_queue 1/1] src: Comment-out code not needed since Linux 3.8 in examples/nf-queue.c

[Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>]

This makes it clear which lines are no longer required.
It also obviates the need to document NFQNL_CFG_CMD_PF_(UN)BIND.

Add comment with sed command to re-enable commented-out code.

Use // comments because my sed-fu is not up to reversing a /* comment block

Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
 examples/nf-queue.c | 48 +++++++++++++++++++++++++-----------------------
 1 file changed, 25 insertions(+), 23 deletions(-)

diff --git a/examples/nf-queue.c b/examples/nf-queue.c
index f6d254a..ee9e4f4 100644
--- a/examples/nf-queue.c
+++ b/examples/nf-queue.c
@@ -151,29 +151,31 @@ int main(int argc, char *argv[])
 	}
 
 	/* PF_(UN)BIND is not needed with kernels 3.8 and later */
-	nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, 0);
-	nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, NFQNL_CFG_CMD_PF_UNBIND);
-
-	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
-		perror("mnl_socket_send");
-		exit(EXIT_FAILURE);
-	}
-
-	nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, 0);
-	nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, NFQNL_CFG_CMD_PF_BIND);
-
-	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
-		perror("mnl_socket_send");
-		exit(EXIT_FAILURE);
-	}
-
-	nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, queue_num);
-	nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, NFQNL_CFG_CMD_BIND);
-
-	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
-		perror("mnl_socket_send");
-		exit(EXIT_FAILURE);
-	}
+	/* Uncomment this code block if you need to cater for an older kernel */
+	/* E.g. sed -i '156,178s+//++' examples/nf-queue.c */
+	//nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, 0);
+	//nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, NFQNL_CFG_CMD_PF_UNBIND);
+	//
+	//if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+	//	perror("mnl_socket_send");
+	//	exit(EXIT_FAILURE);
+	//}
+	//
+	//nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, 0);
+	//nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, NFQNL_CFG_CMD_PF_BIND);
+	//
+	//if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+	//	perror("mnl_socket_send");
+	//	exit(EXIT_FAILURE);
+	//}
+	//
+	//nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, queue_num);
+	//nfq_nlmsg_cfg_put_cmd(nlh, AF_INET, NFQNL_CFG_CMD_BIND);
+	//
+	//if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+	//	perror("mnl_socket_send");
+	//	exit(EXIT_FAILURE);
+	//}
 
 	nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, queue_num);
 	nfq_nlmsg_cfg_put_params(nlh, NFQNL_COPY_PACKET, 0xffff);
-- 
2.14.5