static unsigned int
tproxy_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct iphdr *iph = ip_hdr(skb);
const struct xt_tproxy_target_info *tgi = par->targinfo;
struct udphdr _hdr, *hp;
struct sock *sk;
hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
if (hp == NULL)
return NF_DROP;
sk = nf_tproxy_get_sock_v4(dev_net(skb->dev), iph->protocol,
iph->saddr, tgi->laddr ? tgi->laddr : iph->daddr,
hp->source, tgi->lport ? tgi->lport : hp->dest,
par->in, true);
/* NOTE: assign_sock consumes our sk reference */
if (sk && nf_tproxy_assign_sock(skb, sk)) {
/* This should be in a separate target, but we don't do multiple
targets on the same rule yet */
skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
pr_debug("redirecting: proto %u %08x:%u -> %08x:%u, mark: %x\n",
iph->protocol, ntohl(iph->daddr), ntohs(hp->dest),
ntohl(tgi->laddr), ntohs(tgi->lport), skb->mark);
return NF_ACCEPT;
}
pr_debug("no socket, dropping: proto %u %08x:%u -> %08x:%u, mark: %x\n",
iph->protocol, ntohl(iph->daddr), ntohs(hp->dest),
ntohl(tgi->laddr), ntohs(tgi->lport), skb->mark);
return NF_DROP;
}
static unsigned int
tproxy_tg4(struct net *net, struct sk_buff *skb, __be32 laddr, __be16 lport,
u_int32_t mark_mask, u_int32_t mark_value)
{
const struct iphdr *iph = ip_hdr(skb);
struct udphdr _hdr, *hp;
struct sock *sk;
hp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_hdr), &_hdr);
if (hp == NULL)
return NF_DROP;
/* check if there's an ongoing connection on the packet
* addresses, this happens if the redirect already happened
* and the current packet belongs to an already established
* connection */
sk = nf_tproxy_get_sock_v4(net, skb, iph->protocol,
iph->saddr, iph->daddr,
hp->source, hp->dest,
skb->dev, NF_TPROXY_LOOKUP_ESTABLISHED);
laddr = nf_tproxy_laddr4(skb, laddr, iph->daddr);
if (!lport)
lport = hp->dest;
/* UDP has no TCP_TIME_WAIT state, so we never enter here */
if (sk && sk->sk_state == TCP_TIME_WAIT)
/* reopening a TIME_WAIT connection needs special handling */
sk = nf_tproxy_handle_time_wait4(net, skb, laddr, lport, sk);
else if (!sk)
/* no, there's no established connection, check if
* there's a listener on the redirected addr/port */
sk = nf_tproxy_get_sock_v4(net, skb, iph->protocol,
iph->saddr, laddr,
hp->source, lport,
skb->dev, NF_TPROXY_LOOKUP_LISTENER);
/* NOTE: assign_sock consumes our sk reference */
if (sk && nf_tproxy_sk_is_transparent(sk)) {
/* This should be in a separate target, but we don't do multiple
targets on the same rule yet */
skb->mark = (skb->mark & ~mark_mask) ^ mark_value;
pr_debug("redirecting: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
iph->protocol, &iph->daddr, ntohs(hp->dest),
&laddr, ntohs(lport), skb->mark);
nf_tproxy_assign_sock(skb, sk);
return NF_ACCEPT;
}
pr_debug("no socket, dropping: proto %hhu %pI4:%hu -> %pI4:%hu, mark: %x\n",
iph->protocol, &iph->saddr, ntohs(hp->source),
&iph->daddr, ntohs(hp->dest), skb->mark);
return NF_DROP;
}
static unsigned int
tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
struct udphdr _hdr, *hp;
struct sock *sk;
const struct in6_addr *laddr;
__be16 lport;
int thoff = 0;
int tproto;
tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
if (tproto < 0) {
pr_debug("unable to find transport header in IPv6 packet, dropping\n");
return NF_DROP;
}
hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
if (hp == NULL) {
pr_debug("unable to grab transport header contents in IPv6 packet, dropping\n");
return NF_DROP;
}
/* check if there's an ongoing connection on the packet
* addresses, this happens if the redirect already happened
* and the current packet belongs to an already established
* connection */
sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff, tproto,
&iph->saddr, &iph->daddr,
hp->source, hp->dest,
xt_in(par), NF_TPROXY_LOOKUP_ESTABLISHED);
laddr = nf_tproxy_laddr6(skb, &tgi->laddr.in6, &iph->daddr);
lport = tgi->lport ? tgi->lport : hp->dest;
/* UDP has no TCP_TIME_WAIT state, so we never enter here */
if (sk && sk->sk_state == TCP_TIME_WAIT) {
const struct xt_tproxy_target_info_v1 *tgi = par->targinfo;
/* reopening a TIME_WAIT connection needs special handling */
sk = nf_tproxy_handle_time_wait6(skb, tproto, thoff,
xt_net(par),
&tgi->laddr.in6,
tgi->lport,
sk);
}
else if (!sk)
/* no there's no established connection, check if
* there's a listener on the redirected addr/port */
sk = nf_tproxy_get_sock_v6(xt_net(par), skb, thoff,
tproto, &iph->saddr, laddr,
hp->source, lport,
xt_in(par), NF_TPROXY_LOOKUP_LISTENER);
/* NOTE: assign_sock consumes our sk reference */
if (sk && nf_tproxy_sk_is_transparent(sk)) {
/* This should be in a separate target, but we don't do multiple
targets on the same rule yet */
skb->mark = (skb->mark & ~tgi->mark_mask) ^ tgi->mark_value;
pr_debug("redirecting: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
tproto, &iph->saddr, ntohs(hp->source),
laddr, ntohs(lport), skb->mark);
nf_tproxy_assign_sock(skb, sk);
return NF_ACCEPT;
}
pr_debug("no socket, dropping: proto %hhu %pI6:%hu -> %pI6:%hu, mark: %x\n",
tproto, &iph->saddr, ntohs(hp->source),
&iph->daddr, ntohs(hp->dest), skb->mark);
return NF_DROP;
}
