diff options
Diffstat (limited to 'examples/nf-queue.c')
| -rw-r--r-- | examples/nf-queue.c | 251 |
1 files changed, 251 insertions, 0 deletions
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), ¶ms); + + 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; +} |