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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>
#include <libnetfilter_log/libnetfilter_log.h>
static int print_pkt(struct nfattr *tb[])
{
if (tb[NFULA_PACKET_HDR-1]) {
struct nfulnl_msg_packet_hdr *ph =
NFA_DATA(tb[NFULA_PACKET_HDR-1]);
printf("hw_protocol=0x%04x hook=%u ",
ntohs(ph->hw_protocol), ph->hook);
}
if (tb[NFULA_MARK-1]) {
u_int32_t mark =
ntohl(*(u_int32_t *)NFA_DATA(tb[NFULA_MARK-1]));
printf("mark=%u ", mark);
}
if (tb[NFULA_IFINDEX_INDEV-1]) {
u_int32_t ifi = ntohl(*(u_int32_t *)NFA_DATA(tb[NFULA_IFINDEX_INDEV-1]));
printf("indev=%u ", ifi);
}
if (tb[NFULA_IFINDEX_OUTDEV-1]) {
u_int32_t ifi = ntohl(*(u_int32_t *)NFA_DATA(tb[NFULA_IFINDEX_OUTDEV-1]));
printf("outdev=%u ", ifi);
}
#if 0
if (tb[NFULA_IFINDEX_PHYSINDEV-1]) {
u_int32_t ifi = ntohl(*(u_int32_t *)NFA_DATA(tb[NFULA_IFINDEX_PHYSINDEV-1]));
printf("physindev=%u ", ifi);
}
if (tb[NFULA_IFINDEX_PHYSOUTDEV-1]) {
u_int32_t ifi = ntohl(*(u_int32_t *)NFA_DATA(tb[NFULA_IFINDEX_PHYSOUTDEV-1]));
printf("physoutdev=%u ", ifi);
}
#endif
if (tb[NFULA_PREFIX-1]) {
char *prefix = NFA_DATA(tb[NFULA_PREFIX-1]);
printf("prefix=\"%s\" ", prefix);
}
if (tb[NFULA_PAYLOAD-1]) {
printf("payload_len=%d ", NFA_PAYLOAD(tb[NFULA_PAYLOAD-1]));
}
fputc('\n', stdout);
return 0;
}
static int cb(struct nfulnl_g_handle *gh, struct nfgenmsg *nfmsg,
struct nfattr *nfa[], void *data)
{
print_pkt(nfa);
}
int main(int argc, char **argv)
{
struct nfulnl_handle *h;
struct nfulnl_g_handle *qh;
struct nfulnl_g_handle *qh100;
struct nfnl_handle *nh;
int rv, fd;
char buf[4096];
h = nfulnl_open();
if (!h) {
fprintf(stderr, "error during nfulnl_open()\n");
exit(1);
}
printf("unbinding existing nf_log handler for AF_INET (if any)\n");
if (nfulnl_unbind_pf(h, AF_INET) < 0) {
fprintf(stderr, "error nfulnl_unbind_pf()\n");
exit(1);
}
printf("binding nfnetlink_log to AF_INET\n");
if (nfulnl_bind_pf(h, AF_INET) < 0) {
fprintf(stderr, "error during nfulnl_bind_pf()\n");
exit(1);
}
printf("binding this socket to group 0\n");
qh = nfulnl_bind_group(h, 0);
if (!qh) {
fprintf(stderr, "no handle for grup 0\n");
exit(1);
}
printf("binding this socket to group 100\n");
qh100 = nfulnl_bind_group(h, 100);
if (!qh100) {
fprintf(stderr, "no handle for group 100\n");
exit(1);
}
printf("setting copy_packet mode\n");
if (nfulnl_set_mode(qh, NFULNL_COPY_PACKET, 0xffff) < 0) {
fprintf(stderr, "can't set packet copy mode\n");
exit(1);
}
nh = nfulnl_nfnlh(h);
fd = nfnl_fd(nh);
printf("registering callback for group 0\n");
nfulnl_callback_register(qh, &cb, NULL);
printf("going into main loop\n");
while ((rv = recv(fd, buf, sizeof(buf), 0)) && rv >= 0) {
struct nlmsghdr *nlh;
printf("pkt received (len=%u)\n", rv);
#if 0
for (nlh = nfnl_get_msg_first(nh, buf, rv);
nlh; nlh = nfnl_get_msg_next(nh, buf, rv)) {
struct nfattr *tb[NFULA_MAX];
struct nfgenmsg *nfmsg;
printf("msg received: ");
nfnl_parse_hdr(nh, nlh, &nfmsg);
rv = nfnl_parse_attr(tb, NFULA_MAX, NFM_NFA(NLMSG_DATA(nlh)), nlh->nlmsg_len-NLMSG_ALIGN(sizeof(struct nfgenmsg)));
if (rv < 0) {
printf("error during parse: %d\n", rv);
break;
}
print_pkt(tb);
}
#else
/* handle messages in just-received packet */
nfulnl_handle_packet(h, buf, rv);
#endif
}
printf("unbinding from group 100\n");
nfulnl_unbind_group(qh100);
printf("unbinding from group 0\n");
nfulnl_unbind_group(qh);
#ifdef INSANE
/* norally, applications SHOULD NOT issue this command,
* since it detaches other programs/sockets from AF_INET, too ! */
printf("unbinding from AF_INET\n");
nfulnl_unbind_pf(h, AF_INET);
#endif
printf("closing handle\n");
nfulnl_close(h);
exit(0);
}
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