[PATCH libnetfilter_queue 1/1] Convert nfq_create_queue(), nfq_bind_pf() & nfq_unbind_pf() to use libmnl

[Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>]

Also remove nfq_errno (incomplete project, never documented).

Main change is to static function __build_send_cfg_msg(). After doing that,
I reinstated nfq_bind_pf() & nfq_unbind_pf() to do what the doc claims
rather than simply returning zero.

Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
 .../libnetfilter_queue/libnetfilter_queue.h   |  4 +-
 src/libnetfilter_queue.c                      | 37 ++++++++-----------
 2 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/include/libnetfilter_queue/libnetfilter_queue.h b/include/libnetfilter_queue/libnetfilter_queue.h
index f254984..9b54489 100644
--- a/include/libnetfilter_queue/libnetfilter_queue.h
+++ b/include/libnetfilter_queue/libnetfilter_queue.h
@@ -18,6 +18,8 @@
 
 #include <libnetfilter_queue/linux_nfnetlink_queue.h>
 
+#define NFQ_BUFFSIZE 8192
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -26,8 +28,6 @@ struct nfq_handle;
 struct nfq_q_handle;
 struct nfq_data;
 
-extern int nfq_errno;
-
 extern struct nfnl_handle *nfq_nfnlh(struct nfq_handle *h);
 extern int nfq_fd(struct nfq_handle *h);
 
diff --git a/src/libnetfilter_queue.c b/src/libnetfilter_queue.c
index ca44a6c..73969ce 100644
--- a/src/libnetfilter_queue.c
+++ b/src/libnetfilter_queue.c
@@ -166,8 +166,6 @@ struct nfq_data {
 	struct nfattr **data;
 };
 
-EXPORT_SYMBOL int nfq_errno;
-
 /***********************************************************************
  * low level stuff
  ***********************************************************************/
@@ -210,22 +208,20 @@ static struct nfq_q_handle *find_qh(struct nfq_handle *h, uint16_t id)
 __build_send_cfg_msg(struct nfq_handle *h, uint8_t command,
 		uint16_t queuenum, uint16_t pf)
 {
-	union {
-		char buf[NFNL_HEADER_LEN
-			+NFA_LENGTH(sizeof(struct nfqnl_msg_config_cmd))];
-		struct nlmsghdr nmh;
-	} u;
-	struct nfqnl_msg_config_cmd cmd;
+	char buf[NFQ_BUFFSIZE];
+	struct nlmsghdr *nlh;
+	int ret;
 
-	nfnl_fill_hdr(h->nfnlssh, &u.nmh, 0, AF_UNSPEC, queuenum,
-			NFQNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
+	nlh = nfq_nlmsg_put2(buf, NFQNL_MSG_CONFIG, queuenum, NLM_F_ACK);
 
-	cmd._pad = 0;
-	cmd.command = command;
-	cmd.pf = htons(pf);
-	nfnl_addattr_l(&u.nmh, sizeof(u), NFQA_CFG_CMD, &cmd, sizeof(cmd));
+	nfq_nlmsg_cfg_put_cmd(nlh, AF_UNSPEC, command);
 
-	return nfnl_query(h->nfnlh, &u.nmh);
+	ret = mnl_socket_sendto(h->nl, nlh, nlh->nlmsg_len);
+	if (ret != -1)
+		ret = mnl_socket_recvfrom(h->nl, buf, sizeof(buf));
+	if (ret != -1)
+		ret = mnl_cb_run(buf, ret, 0, h->portid, NULL, NULL);
+	return ret;
 }
 
 static int __nfq_rcv_pkt(struct nlmsghdr *nlh, struct nfattr *nfa[],
@@ -453,15 +449,13 @@ struct nfq_handle *nfq_open_nfnl(struct nfnl_handle *nfnlh)
 
 	h->nfnlssh = nfnl_subsys_open(h->nfnlh, NFNL_SUBSYS_QUEUE,
 				      NFQNL_MSG_MAX, 0);
-	if (!h->nfnlssh) {
-		/* FIXME: nfq_errno */
+	if (!h->nfnlssh)
 		goto out_free;
-	}
+// THIS IS nfq_open_nfnl() - ENTIRE FUNCTION WILL BE REMOVED EVENTUALLY
 
 	pkt_cb.data = h;
 	err = nfnl_callback_register(h->nfnlssh, NFQNL_MSG_PACKET, &pkt_cb);
 	if (err < 0) {
-		nfq_errno = err;
 		goto out_close;
 	}
 
@@ -523,7 +517,7 @@ int nfq_close(struct nfq_handle *h)
 EXPORT_SYMBOL
 int nfq_bind_pf(struct nfq_handle *h, uint16_t pf)
 {
-	return 0;
+	return __build_send_cfg_msg(h, NFQNL_CFG_CMD_PF_BIND, 0, pf);
 }
 
 /**
@@ -539,7 +533,7 @@ int nfq_bind_pf(struct nfq_handle *h, uint16_t pf)
 EXPORT_SYMBOL
 int nfq_unbind_pf(struct nfq_handle *h, uint16_t pf)
 {
-	return 0;
+	return __build_send_cfg_msg(h, NFQNL_CFG_CMD_PF_UNBIND, 0, pf);
 }
 
 
@@ -606,7 +600,6 @@ struct nfq_q_handle *nfq_create_queue(struct nfq_handle *h, uint16_t num,
 
 	ret = __build_send_cfg_msg(h, NFQNL_CFG_CMD_BIND, num, 0);
 	if (ret < 0) {
-		nfq_errno = ret;
 		free(qh);
 		return NULL;
 	}
-- 
2.35.8