add nf-queue.c example file for nfnetlink_queue

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 257 insertions, 1 deletions

diff --git a/examples/Makefile.am b/examples/Makefile.am
index 8102d2f..15aa0e0 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -5,7 +5,8 @@ check_PROGRAMS = rtnl-link-dump rtnl-link-dump2 rtnl-link-dump3 \
 		 rtnl-link-set \
 		 rtnl-route-add \
 		 rtnl-route-dump \
-		 genl-family-get
+		 genl-family-get \
+		 nf-queue
 
 rtnl_link_dump_SOURCES = rtnl-link-dump.c
 rtnl_link_dump_LDADD = ../src/libmnl.la
@@ -38,3 +39,7 @@ rtnl_route_dump_LDFLAGS = -dynamic -ldl
 genl_family_get_SOURCES = genl-family-get.c
 genl_family_get_LDADD = ../src/libmnl.la
 genl_family_get_LDFLAGS = -dynamic -ldl
+
+nf_queue_SOURCES = nf-queue.c
+nf_queue_LDADD = ../src/libmnl.la
+nf_queue_LDFLAGS = -dynamic -ldl
diff --git a/examples/nf-queue.c b/examples/nf-queue.c
new file mode 100644
index 0000000..cbbf91f
--- /dev/null
+++ b/examples/nf-queue.c
@@ -0,0 +1,251 @@
+/*
+ * (C) 2010 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <time.h>
+#include <arpa/inet.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink.h>
+
+#ifndef aligned_be64
+#define aligned_be64 u_int64_t __attribute__((aligned(8)))
+#endif
+
+#include <linux/netfilter/nfnetlink_queue.h>
+
+static int parse_attr_cb(const struct nlattr *attr, void *data)
+{
+        const struct nlattr **tb = (const struct nlattr **)data;
+	int type = mnl_attr_get_type(attr);
+
+	if (mnl_attr_type_valid(attr, NFQA_MAX) < 0) {
+		perror("mnl_attr_type_valid");
+		return MNL_CB_ERROR;
+	}
+	switch(type) {
+	case NFQA_MARK:
+	case NFQA_IFINDEX_INDEV:
+	case NFQA_IFINDEX_OUTDEV:
+	case NFQA_IFINDEX_PHYSINDEV:
+	case NFQA_IFINDEX_PHYSOUTDEV:
+		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
+			perror("mnl_attr_validate");
+			return MNL_CB_ERROR;
+		}
+		break;
+	case NFQA_TIMESTAMP:
+		if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
+		    sizeof(struct nfqnl_msg_packet_timestamp)) < 0) {
+			perror("mnl_attr_validate");
+			return MNL_CB_ERROR;
+		}
+		break;
+	case NFQA_HWADDR:
+		if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
+		    sizeof(struct nfqnl_msg_packet_hw)) < 0) {
+			perror("mnl_attr_validate");
+			return MNL_CB_ERROR;
+		}
+		break;
+	case NFQA_PAYLOAD:
+		break;
+	}
+	tb[type] = attr;
+	return MNL_CB_OK;
+}
+
+static int queue_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct nlattr *tb[NFQA_MAX+1] = {};
+	struct nfqnl_msg_packet_hdr *ph = NULL;
+	uint32_t id = 0;
+
+	mnl_attr_parse(nlh, sizeof(struct nfgenmsg), parse_attr_cb, tb);
+	if (tb[NFQA_PACKET_HDR]) {
+		ph = mnl_attr_get_payload(tb[NFQA_PACKET_HDR]);
+		id = ntohl(ph->packet_id);
+	}
+	printf("packet received (id=%u hw=0x%04x hook=%u)\n",
+		id, ntohs(ph->hw_protocol), ph->hook);
+
+	return MNL_CB_OK + id;
+}
+
+static struct nlmsghdr *
+nfq_build_cfg_pf_request(char *buf, uint8_t command)
+{
+	struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
+	nlh->nlmsg_type	= (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_CONFIG;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+
+	struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+	nfg->nfgen_family = AF_UNSPEC;
+	nfg->version = NFNETLINK_V0;
+
+	struct nfqnl_msg_config_cmd cmd = {
+		.command = command,
+		.pf = htons(AF_INET),
+	};
+	mnl_attr_put(nlh, NFQA_CFG_CMD, sizeof(cmd), &cmd);
+
+	return nlh;
+}
+
+static struct nlmsghdr *
+nfq_build_cfg_request(char *buf, uint8_t command, int queue_num)
+{
+	struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
+	nlh->nlmsg_type	= (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_CONFIG;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+
+	struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+	nfg->nfgen_family = AF_UNSPEC;
+	nfg->version = NFNETLINK_V0;
+	nfg->res_id = htons(queue_num);
+
+	struct nfqnl_msg_config_cmd cmd = {
+		.command = command,
+		.pf = htons(AF_INET),
+	};
+	mnl_attr_put(nlh, NFQA_CFG_CMD, sizeof(cmd), &cmd);
+
+	return nlh;
+}
+
+static struct nlmsghdr *
+nfq_build_cfg_params(char *buf, uint8_t mode, int range, int queue_num)
+{
+	struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
+	nlh->nlmsg_type	= (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_CONFIG;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+
+	struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+	nfg->nfgen_family = AF_UNSPEC;
+	nfg->version = NFNETLINK_V0;
+	nfg->res_id = htons(queue_num);
+
+	struct nfqnl_msg_config_params params = {
+		.copy_range = htonl(range),
+		.copy_mode = mode,
+	};
+	mnl_attr_put(nlh, NFQA_CFG_PARAMS, sizeof(params), &params);
+
+	return nlh;
+}
+
+struct nlmsghdr *nfq_build_verdict(char *buf, int id, int queue_num, int verd)
+{
+	struct nlmsghdr *nlh;
+	struct nfgenmsg *nfg;
+
+	nlh = mnl_nlmsg_put_header(buf);
+	nlh->nlmsg_type = (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_VERDICT;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+	nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+	nfg->nfgen_family = AF_UNSPEC;
+	nfg->version = NFNETLINK_V0;
+	nfg->res_id = htons(queue_num);
+
+	struct nfqnl_msg_verdict_hdr vh = {
+		.verdict = htonl(verd),
+		.id = htonl(id),
+	};
+	mnl_attr_put(nlh, NFQA_VERDICT_HDR, sizeof(vh), &vh);
+
+	return nlh;
+}
+
+int main(int argc, char *argv[])
+{
+	struct mnl_socket *nl;
+	char buf[getpagesize()];
+	struct nlmsghdr *nlh;
+	int ret;
+	unsigned int portid, queue_num;
+
+	if (argc != 2) {
+		printf("Usage: %s [queue_num]\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+	queue_num = atoi(argv[1]);
+
+	nl = mnl_socket_open(NETLINK_NETFILTER);
+	if (nl == NULL) {
+		perror("mnl_socket_open");
+		exit(EXIT_FAILURE);
+	}
+
+	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
+		perror("mnl_socket_bind");
+		exit(EXIT_FAILURE);
+	}
+	portid = mnl_socket_get_portid(nl);
+
+	nlh = nfq_build_cfg_pf_request(buf, NFQNL_CFG_CMD_PF_UNBIND);
+
+	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+		perror("mnl_socket_send");
+		exit(EXIT_FAILURE);
+	}
+
+	nlh = nfq_build_cfg_pf_request(buf, NFQNL_CFG_CMD_PF_BIND);
+
+	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+		perror("mnl_socket_send");
+		exit(EXIT_FAILURE);
+	}
+
+	nlh = nfq_build_cfg_request(buf, NFQNL_CFG_CMD_BIND, queue_num);
+
+	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+		perror("mnl_socket_send");
+		exit(EXIT_FAILURE);
+	}
+
+	nlh = nfq_build_cfg_params(buf, NFQNL_COPY_PACKET, 0xFFFF, queue_num);
+
+	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+		perror("mnl_socket_send");
+		exit(EXIT_FAILURE);
+	}
+
+	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	if (ret == -1) {
+		perror("mnl_socket_recvfrom");
+		exit(EXIT_FAILURE);
+	}
+	while (ret > 0) {
+		uint32_t id;
+
+		ret = mnl_cb_run(buf, ret, 0, portid, queue_cb, NULL);
+		if (ret < 0){
+			perror("mnl_cb_run");
+			exit(EXIT_FAILURE);
+		}
+
+		id = ret - MNL_CB_OK;
+		nlh = nfq_build_verdict(buf, id, queue_num, NF_ACCEPT);
+		if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+			perror("mnl_socket_send");
+			exit(EXIT_FAILURE);
+		}
+
+		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+		if (ret == -1) {
+			perror("mnl_socket_recvfrom");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	mnl_socket_close(nl);
+
+	return 0;
+}