int main()
{
int ret;
struct nfct_handle *h;
struct nf_conntrack *ct;
ct = nfct_new();
if (!ct) {
perror("nfct_new");
return 0;
}
nfct_set_attr_u8(ct, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(ct, ATTR_IPV4_SRC, inet_addr("1.1.1.1"));
nfct_set_attr_u32(ct, ATTR_IPV4_DST, inet_addr("2.2.2.2"));
nfct_set_attr_u8(ct, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(ct, ATTR_PORT_SRC, htons(20));
nfct_set_attr_u16(ct, ATTR_PORT_DST, htons(10));
h = nfct_open(CONNTRACK, 0);
if (!h) {
perror("nfct_open");
return -1;
}
ret = nfct_query(h, NFCT_Q_DESTROY, ct);
printf("TEST: delete conntrack (%d)(%s)\n", ret, strerror(errno));
if (ret == -1)
exit(EXIT_FAILURE);
nfct_close(h);
}
/* So, this packet has hit the connection tracking matching code.
Mangle it, and change the expectation to match the new version. */
static unsigned int
nf_nat_rpc(struct pkt_buff *pkt, int dir, struct nf_expect *exp,
uint8_t proto, uint32_t *port_ptr)
{
const struct nf_conntrack *expected;
struct nf_conntrack *nat_tuple;
uint16_t initial_port, port;
expected = nfexp_get_attr(exp, ATTR_EXP_EXPECTED);
nat_tuple = nfct_new();
if (nat_tuple == NULL)
return NF_ACCEPT;
initial_port = nfct_get_attr_u16(expected, ATTR_PORT_DST);
nfexp_set_attr_u32(exp, ATTR_EXP_NAT_DIR, !dir);
/* libnetfilter_conntrack needs this */
nfct_set_attr_u8(nat_tuple, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(nat_tuple, ATTR_IPV4_SRC, 0);
nfct_set_attr_u32(nat_tuple, ATTR_IPV4_DST, 0);
nfct_set_attr_u8(nat_tuple, ATTR_L4PROTO, proto);
nfct_set_attr_u16(nat_tuple, ATTR_PORT_DST, 0);
/* When you see the packet, we need to NAT it the same as the
* this one. */
nfexp_set_attr(exp, ATTR_EXP_FN, "nat-follow-master");
/* Try to get same port: if not, try to change it. */
for (port = ntohs(initial_port); port != 0; port++) {
int ret;
nfct_set_attr_u16(nat_tuple, ATTR_PORT_SRC, htons(port));
nfexp_set_attr(exp, ATTR_EXP_NAT_TUPLE, nat_tuple);
ret = cthelper_add_expect(exp);
if (ret == 0)
break;
else if (ret != -EBUSY) {
port = 0;
break;
}
}
nfct_destroy(nat_tuple);
if (port == 0)
return NF_DROP;
*port_ptr = htonl(port);
return NF_ACCEPT;
}
int main(void)
{
int ret;
struct nfct_handle *h;
struct nf_conntrack *expected;
struct nf_expect *exp;
expected = nfct_new();
if (!expected) {
perror("nfct_new");
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(expected, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(expected, ATTR_IPV4_SRC, inet_addr("1.1.1.1"));
nfct_set_attr_u32(expected, ATTR_IPV4_DST, inet_addr("2.2.2.2"));
nfct_set_attr_u8(expected, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(expected, ATTR_PORT_SRC, 0);
nfct_set_attr_u16(expected, ATTR_PORT_DST, htons(10241));
exp = nfexp_new();
if (!exp) {
perror("nfexp_new");
nfct_destroy(expected);
exit(EXIT_FAILURE);
}
nfexp_set_attr(exp, ATTR_EXP_EXPECTED, expected);
h = nfct_open(EXPECT, 0);
if (!h) {
perror("nfct_open");
nfct_destroy(expected);
return -1;
}
ret = nfexp_query(h, NFCT_Q_DESTROY, exp);
printf("TEST: delete expectation ");
if (ret == -1)
printf("(%d)(%s)\n", ret, strerror(errno));
else
printf("(OK)\n");
nfct_close(h);
nfct_destroy(expected);
ret == -1 ? exit(EXIT_FAILURE) : exit(EXIT_SUCCESS);
}
int get_incoming_mark(union mysockaddr *peer_addr, struct all_addr *local_addr, int istcp, unsigned int *markp)
{
struct nf_conntrack *ct;
struct nfct_handle *h;
gotit = 0;
if ((ct = nfct_new()))
{
nfct_set_attr_u8(ct, ATTR_L4PROTO, istcp ? IPPROTO_TCP : IPPROTO_UDP);
nfct_set_attr_u16(ct, ATTR_PORT_DST, htons(daemon->port));
#ifdef HAVE_IPV6
if (peer_addr->sa.sa_family == AF_INET6)
{
nfct_set_attr_u8(ct, ATTR_L3PROTO, AF_INET6);
nfct_set_attr(ct, ATTR_IPV6_SRC, peer_addr->in6.sin6_addr.s6_addr);
nfct_set_attr_u16(ct, ATTR_PORT_SRC, peer_addr->in6.sin6_port);
nfct_set_attr(ct, ATTR_IPV6_DST, local_addr->addr.addr6.s6_addr);
}
else
#endif
{
nfct_set_attr_u8(ct, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(ct, ATTR_IPV4_SRC, peer_addr->in.sin_addr.s_addr);
nfct_set_attr_u16(ct, ATTR_PORT_SRC, peer_addr->in.sin_port);
nfct_set_attr_u32(ct, ATTR_IPV4_DST, local_addr->addr.addr4.s_addr);
}
if ((h = nfct_open(CONNTRACK, 0)))
{
nfct_callback_register(h, NFCT_T_ALL, callback, (void *)markp);
if (nfct_query(h, NFCT_Q_GET, ct) == -1)
{
static int warned = 0;
if (!warned)
{
my_syslog(LOG_ERR, _("Conntrack connection mark retrieval failed: %s"), strerror(errno));
warned = 1;
}
}
nfct_close(h);
}
nfct_destroy(ct);
}
return gotit;
}
int nl_create_conntrack(struct nfct_handle *h,
const struct nf_conntrack *orig,
int timeout)
{
int ret;
struct nf_conntrack *ct;
ct = nfct_clone(orig);
if (ct == NULL)
return -1;
if (timeout > 0)
nfct_set_attr_u32(ct, ATTR_TIMEOUT, timeout);
/* we hit error if we try to change the expected bit */
if (nfct_attr_is_set(ct, ATTR_STATUS)) {
uint32_t status = nfct_get_attr_u32(ct, ATTR_STATUS);
status &= ~IPS_EXPECTED;
nfct_set_attr_u32(ct, ATTR_STATUS, status);
}
nfct_setobjopt(ct, NFCT_SOPT_SETUP_REPLY);
/* disable TCP window tracking for recovered connections if required */
if (nfct_attr_is_set(ct, ATTR_TCP_STATE)) {
uint8_t flags = IP_CT_TCP_FLAG_SACK_PERM;
if (!CONFIG(sync).tcp_window_tracking)
flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
else
flags |= IP_CT_TCP_FLAG_WINDOW_SCALE;
/* FIXME: workaround, we should send TCP flags in updates */
if (nfct_get_attr_u8(ct, ATTR_TCP_STATE) >=
TCP_CONNTRACK_TIME_WAIT) {
flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
}
nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_ORIG, flags);
nfct_set_attr_u8(ct, ATTR_TCP_MASK_ORIG, flags);
nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_REPL, flags);
nfct_set_attr_u8(ct, ATTR_TCP_MASK_REPL, flags);
}
ret = nfct_query(h, NFCT_Q_CREATE, ct);
nfct_destroy(ct);
return ret;
}
static int test_cmp_attr32(int attr, bool at1, bool at2,
uint32_t v1, uint32_t v2, unsigned int flags)
{
struct nf_conntrack *ct1 = nfct_new();
struct nf_conntrack *ct2 = nfct_new();
int ret;
if (at1)
nfct_set_attr_u32(ct1, attr, v1);
if (at2)
nfct_set_attr_u32(ct2, attr, v2);
ret = nfct_cmp(ct1, ct2, NFCT_CMP_ALL | flags);
nfct_destroy(ct1);
nfct_destroy(ct2);
return ret;
}
int main()
{
int ret;
struct nfct_handle *h;
struct nf_conntrack *ct;
ct = nfct_new();
if (!ct) {
perror("nfct_new");
return 0;
}
nfct_set_attr_u8(ct, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(ct, ATTR_IPV4_SRC, inet_addr("1.1.1.1"));
nfct_set_attr_u32(ct, ATTR_IPV4_DST, inet_addr("2.2.2.2"));
nfct_set_attr_u8(ct, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(ct, ATTR_PORT_SRC, htons(20));
nfct_set_attr_u16(ct, ATTR_PORT_DST, htons(10));
nfct_setobjopt(ct, NFCT_SOPT_SETUP_REPLY);
nfct_set_attr_u8(ct, ATTR_TCP_STATE, TCP_CONNTRACK_LISTEN);
nfct_set_attr_u32(ct, ATTR_TIMEOUT, 100);
nfct_set_attr_u32(ct, ATTR_SNAT_IPV4, inet_addr("8.8.8.8"));
h = nfct_open(CONNTRACK, 0);
if (!h) {
perror("nfct_open");
return -1;
}
ret = nfct_query(h, NFCT_Q_CREATE, ct);
printf("TEST: create conntrack (%d)(%s)\n", ret, strerror(errno));
if (ret == -1)
exit(EXIT_FAILURE);
nfct_close(h);
}
int main(void)
{
struct mnl_socket *nl;
struct nlmsghdr *nlh;
struct nfgenmsg *nfh;
char buf[MNL_SOCKET_BUFFER_SIZE];
unsigned int seq, portid;
struct nf_conntrack *ct;
int ret;
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 = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_DELETE;
nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
nlh->nlmsg_seq = seq = time(NULL);
nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
nfh->nfgen_family = AF_INET;
nfh->version = NFNETLINK_V0;
nfh->res_id = 0;
ct = nfct_new();
if (ct == NULL) {
perror("nfct_new");
return 0;
}
nfct_set_attr_u8(ct, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(ct, ATTR_IPV4_SRC, inet_addr("1.1.1.1"));
nfct_set_attr_u32(ct, ATTR_IPV4_DST, inet_addr("2.2.2.2"));
nfct_set_attr_u8(ct, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(ct, ATTR_PORT_SRC, htons(20));
nfct_set_attr_u16(ct, ATTR_PORT_DST, htons(10));
nfct_nlmsg_build(nlh, ct);
ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL);
if (ret <= MNL_CB_STOP)
break;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
if (ret == -1) {
perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
mnl_socket_close(nl);
return 0;
}
int nl_update_conntrack(struct nfct_handle *h,
const struct nf_conntrack *orig,
int timeout)
{
int ret;
struct nf_conntrack *ct;
ct = nfct_clone(orig);
if (ct == NULL)
return -1;
if (timeout > 0)
nfct_set_attr_u32(ct, ATTR_TIMEOUT, timeout);
/* unset NAT info, otherwise we hit error */
nfct_attr_unset(ct, ATTR_SNAT_IPV4);
nfct_attr_unset(ct, ATTR_DNAT_IPV4);
nfct_attr_unset(ct, ATTR_SNAT_PORT);
nfct_attr_unset(ct, ATTR_DNAT_PORT);
if (nfct_attr_is_set(ct, ATTR_STATUS)) {
uint32_t status = nfct_get_attr_u32(ct, ATTR_STATUS);
status &= ~IPS_NAT_MASK;
nfct_set_attr_u32(ct, ATTR_STATUS, status);
}
/* we have to unset the helper to avoid EBUSY in reset timers */
if (nfct_attr_is_set(ct, ATTR_HELPER_NAME))
nfct_attr_unset(ct, ATTR_HELPER_NAME);
/* we hit error if we try to update the master conntrack */
if (ct_is_related(ct)) {
nfct_attr_unset(ct, ATTR_MASTER_L3PROTO);
nfct_attr_unset(ct, ATTR_MASTER_L4PROTO);
nfct_attr_unset(ct, ATTR_MASTER_IPV4_SRC);
nfct_attr_unset(ct, ATTR_MASTER_IPV4_DST);
nfct_attr_unset(ct, ATTR_MASTER_IPV6_SRC);
nfct_attr_unset(ct, ATTR_MASTER_IPV6_DST);
nfct_attr_unset(ct, ATTR_MASTER_PORT_SRC);
nfct_attr_unset(ct, ATTR_MASTER_PORT_DST);
}
/* disable TCP window tracking for recovered connections if required */
if (nfct_attr_is_set(ct, ATTR_TCP_STATE)) {
uint8_t flags = IP_CT_TCP_FLAG_SACK_PERM;
if (!CONFIG(sync).tcp_window_tracking)
flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
else
flags |= IP_CT_TCP_FLAG_WINDOW_SCALE;
/* FIXME: workaround, we should send TCP flags in updates */
if (nfct_get_attr_u8(ct, ATTR_TCP_STATE) >=
TCP_CONNTRACK_TIME_WAIT) {
flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
}
nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_ORIG, flags);
nfct_set_attr_u8(ct, ATTR_TCP_MASK_ORIG, flags);
nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_REPL, flags);
nfct_set_attr_u8(ct, ATTR_TCP_MASK_REPL, flags);
}
ret = nfct_query(h, NFCT_Q_UPDATE, ct);
nfct_destroy(ct);
return ret;
}
int main(void)
{
int ret;
struct nfct_handle *h;
struct nf_conntrack *master, *expected, *mask, *nat;
struct nf_expect *exp;
/*
* Step 1: Setup master conntrack
*/
master = nfct_new();
if (!master) {
perror("nfct_new");
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(master, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(master, ATTR_IPV4_SRC, inet_addr("1.1.1.1"));
nfct_set_attr_u32(master, ATTR_IPV4_DST, inet_addr("2.2.2.2"));
nfct_set_attr_u8(master, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(master, ATTR_PORT_SRC, htons(1025));
nfct_set_attr_u16(master, ATTR_PORT_DST, htons(21));
nfct_setobjopt(master, NFCT_SOPT_SETUP_REPLY);
nfct_set_attr_u8(master, ATTR_TCP_STATE, TCP_CONNTRACK_ESTABLISHED);
nfct_set_attr_u32(master, ATTR_TIMEOUT, 200);
nfct_set_attr(master, ATTR_HELPER_NAME, "ftp");
h = nfct_open(CONNTRACK, 0);
if (!h) {
perror("nfct_open");
nfct_destroy(master);
return -1;
}
ret = nfct_query(h, NFCT_Q_CREATE, master);
printf("TEST: add master conntrack ");
if (ret == -1)
printf("(%d)(%s)\n", ret, strerror(errno));
else
printf("(OK)\n");
nfct_close(h);
expected = nfct_new();
if (!expected) {
perror("nfct_new");
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(expected, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(expected, ATTR_IPV4_SRC, inet_addr("1.1.1.1"));
nfct_set_attr_u32(expected, ATTR_IPV4_DST, inet_addr("2.2.2.2"));
nfct_set_attr_u8(expected, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(expected, ATTR_PORT_SRC, 0);
nfct_set_attr_u16(expected, ATTR_PORT_DST, htons(10241));
mask = nfct_new();
if (!mask) {
perror("nfct_new");
nfct_destroy(master);
nfct_destroy(expected);
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(mask, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(mask, ATTR_IPV4_SRC, 0xffffffff);
nfct_set_attr_u32(mask, ATTR_IPV4_DST, 0xffffffff);
nfct_set_attr_u8(mask, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(mask, ATTR_PORT_SRC, 0x0000);
nfct_set_attr_u16(mask, ATTR_PORT_DST, 0xffff);
nat = nfct_new();
if (!nat) {
perror("nfct_new");
nfct_destroy(mask);
nfct_destroy(master);
nfct_destroy(expected);
exit(EXIT_FAILURE);
}
nfct_set_attr_u8(nat, ATTR_L3PROTO, AF_INET);
nfct_set_attr_u32(nat, ATTR_IPV4_SRC, inet_addr("3.3.3.3"));
nfct_set_attr_u32(nat, ATTR_IPV4_DST, 0);
nfct_set_attr_u8(nat, ATTR_L4PROTO, IPPROTO_TCP);
nfct_set_attr_u16(nat, ATTR_PORT_SRC, 12345);
nfct_set_attr_u16(nat, ATTR_PORT_DST, 0);
/*
* Step 2: Setup expectation
*/
exp = nfexp_new();
if (!exp) {
perror("nfexp_new");
nfct_destroy(master);
nfct_destroy(expected);
nfct_destroy(mask);
exit(EXIT_FAILURE);
}
nfexp_set_attr(exp, ATTR_EXP_MASTER, master);
nfexp_set_attr(exp, ATTR_EXP_EXPECTED, expected);
nfexp_set_attr(exp, ATTR_EXP_MASK, mask);
nfexp_set_attr(exp, ATTR_EXP_NAT_TUPLE, nat);
nfexp_set_attr_u32(exp, ATTR_EXP_NAT_DIR, 0);
nfexp_set_attr_u32(exp, ATTR_EXP_TIMEOUT, 200);
nfct_destroy(master);
nfct_destroy(expected);
nfct_destroy(mask);
nfct_destroy(nat);
h = nfct_open(EXPECT, 0);
if (!h) {
perror("nfct_open");
return -1;
}
ret = nfexp_query(h, NFCT_Q_CREATE, exp);
printf("TEST: create expectation ");
if (ret == -1)
printf("(%d)(%s)\n", ret, strerror(errno));
else
printf("(OK)\n");
nfct_close(h);
ret == -1 ? exit(EXIT_FAILURE) : exit(EXIT_SUCCESS);
}
int get_nat_ext_addr(struct sockaddr* src, struct sockaddr *dst, uint8_t proto,
struct sockaddr_storage* ret_ext)
{
struct mnl_socket *nl;
struct nlmsghdr *nlh;
struct nfgenmsg *nfh;
char buf[MNL_SOCKET_BUFFER_SIZE];
unsigned int seq, portid;
struct nf_conntrack *ct;
int ret;
struct data_cb_s data;
if ((!src)&&(!dst)) {
return 0;
}
if (src->sa_family != dst->sa_family) {
return 0;
}
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL) {
// perror("mnl_socket_open");
goto free_nl;
}
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
// perror("mnl_socket_bind");
goto free_nl;
}
portid = mnl_socket_get_portid(nl);
memset(buf, 0, sizeof(buf));
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_GET;
nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
nlh->nlmsg_seq = seq = time(NULL);
nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
nfh->nfgen_family = src->sa_family;
nfh->version = NFNETLINK_V0;
nfh->res_id = 0;
ct = nfct_new();
if (ct == NULL) {
goto free_nl;
}
nfct_set_attr_u8(ct, ATTR_L3PROTO, src->sa_family);
if (src->sa_family == AF_INET) {
struct sockaddr_in *src4 = (struct sockaddr_in *)src;
struct sockaddr_in *dst4 = (struct sockaddr_in *)dst;
nfct_set_attr_u32(ct, ATTR_IPV4_SRC, src4->sin_addr.s_addr);
nfct_set_attr_u32(ct, ATTR_IPV4_DST, dst4->sin_addr.s_addr);
nfct_set_attr_u16(ct, ATTR_PORT_SRC, src4->sin_port);
nfct_set_attr_u16(ct, ATTR_PORT_DST, dst4->sin_port);
} else if (src->sa_family == AF_INET6) {
struct sockaddr_in6 *src6 = (struct sockaddr_in6 *)src;
struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;
nfct_set_attr(ct, ATTR_IPV6_SRC, &src6->sin6_addr);
nfct_set_attr(ct, ATTR_IPV6_DST, &dst6->sin6_addr);
nfct_set_attr_u16(ct, ATTR_PORT_SRC, src6->sin6_port);
nfct_set_attr_u16(ct, ATTR_PORT_DST, dst6->sin6_port);
}
nfct_set_attr_u8(ct, ATTR_L4PROTO, proto);
nfct_nlmsg_build(nlh, ct);
ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
if (ret == -1) {
goto free_ct;
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
data.ext = ret_ext;
data.found = 0;
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, data_cb, &data);
if (ret <= MNL_CB_STOP)
break;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
free_ct:
nfct_destroy(ct);
free_nl:
mnl_socket_close(nl);
return data.found;
}
static int
cthelper_process_packet(const uint8_t *pkt, uint32_t pktlen,
struct ctd_helper *h, int proto, uint16_t port,
int type)
{
struct pkt_buff *pktb;
struct cthelper_proto_l2l3_helper *l3h;
struct cthelper_proto_l4_helper *l4h;
unsigned int l3hdr_len, l4protonum;
struct nf_ct_entry *ct;
int ret, this_proto;
uint32_t dataoff, ctinfo = 0;
l3h = cthelper_proto_l2l3_helper_find(pkt, &l4protonum, &l3hdr_len);
if (l3h == NULL) {
fprintf(stderr, "Unsupported layer 3 protocol, skipping.\n");
return -1;
}
l4h = cthelper_proto_l4_helper_find(pkt, l4protonum);
if (l4h == NULL) {
fprintf(stderr, "Unsupported layer 4 protocol, skipping.\n");
return -1;
}
/* get layer 3 header. */
pkt += l3h->l2hdr_len;
pktlen -= l3h->l2hdr_len;
/* skip packet with mismatching protocol */
this_proto = l3h->l4pkt_proto(pkt);
if (this_proto != proto) {
cthelper_test_stats.pkt_mismatch_proto++;
return 0;
}
/* Look for the fake conntrack. */
ct = ct_find(pkt, l3hdr_len, l3h, l4h, &ctinfo);
if (ct == NULL) {
/* It doesn't exist any, create one. */
ct = ct_alloc(pkt, l3hdr_len, l3h, l4h);
if (ct == NULL) {
fprintf(stderr, "Not enough memory\n");
return -1;
}
ct_add(ct);
ctinfo += IP_CT_NEW;
} else
ctinfo += IP_CT_ESTABLISHED;
/* skip packets with mismatching ports */
if (!l4h->l4ct_cmp_port(ct->myct->ct, ntohs(port))) {
cthelper_test_stats.pkt_mismatch_port++;
return -1;
}
/*
* FIXME: reminder, implement this below in the kernel for cthelper.
*/
/* This packet contains no data, skip it. */
/* if (l4h->l4pkt_no_data && l4h->l4pkt_no_data(pkt + l3hdr_len)) {
NFG_DEBUG("skipping packet with no data\n");
continue;
} */
/* Create the fake network buffer. */
pktb = pktb_alloc(AF_INET, pkt, pktlen, 128);
if (pktb == NULL) {
fprintf(stderr, "Not enough memory\n");
return -1;
}
dataoff = l3h->l3pkt_hdr_len(pkt);
if (dataoff > pktb_len(pktb)) {
fprintf(stderr, "wrong layer 3 offset: %d > %d\n",
dataoff, pktb_len(pktb));
return -1;
}
/* tweak to run DNAT mangling code using the same PCAP file. */
if (type == TEST_DNAT) {
struct nf_conntrack *tmp = ct->myct->ct;
/* as long as this is tested, who cares the destination IP? */
in_addr_t addr = inet_addr("1.1.1.1");
/* clone the real conntrack, to add DNAT information */
ct->myct->ct = nfct_clone(ct->myct->ct);
/* set fake DNAT information */
nfct_set_attr_u32(ct->myct->ct, ATTR_STATUS, IPS_DST_NAT);
nfct_set_attr_u32(ct->myct->ct, ATTR_ORIG_IPV4_DST, addr);
/* pass it to helper */
ret = h->cb(pktb, dataoff, ct->myct, ctinfo);
/* restore real conntrack */
nfct_destroy(ct->myct->ct);
ct->myct->ct = tmp;
if (pktb_mangled(pktb)) {
int i;
uint8_t *data = pktb_network_header(pktb);
printf("\e[1;31mmangled content: ", pktb_len(pktb));
for (i=0; i < pktb_len(pktb); i++)
printf("%c", data[i]);
printf("\e[0m\n");
}
} else
