fix xt_* calls on ubuntu 18.04 / linux 4.15

src/compat_xtables.h

@@ -90,7 +90,7 @@ static inline void proc_remove(struct proc_dir_entry *de)
 static inline struct net *par_net(const struct xt_action_param *par)
 {
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0)
-    return par->net;
+    return xt_net(par);
 #else
     return dev_net((par->in != NULL) ? par->in : par->out);
 #endif

src/ts3init_match.c

@@ -141,7 +141,7 @@ static inline __u8* get_payload(const struct sk_buff *skb, const struct xt_actio
 static int calculate_cookie(const struct sk_buff *skb, const struct xt_action_param *par, 
                        struct udphdr *udp, __u64 k0, __u64 k1, __u64* out)
 {
-    switch (par->family)
+    switch (xt_family(par))
     {
     case NFPROTO_IPV4:
         {

src/ts3init_target.c

@@ -47,7 +47,7 @@ ts3init_send_ipv6_reply(struct sk_buff *oldskb, const struct xt_action_param *pa
     struct udphdr *udp;
     struct flowi6 fl;
     struct dst_entry *dst = NULL;
-    struct net *net = dev_net((par->in != NULL) ? par->in : par->out);
+    struct net *net = dev_net((xt_in(par) != NULL) ? xt_in(par) : xt_out(par));
 
     skb = alloc_skb(LL_MAX_HEADER + sizeof(*ip) +
              sizeof(*udp) + payload_size, GFP_ATOMIC);