Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / net / ipv4 / netfilter / ip_nat_standalone.c
index 79f56f6..67e6767 100644 (file)
@@ -31,8 +31,8 @@
 #include <net/checksum.h>
 #include <linux/spinlock.h>
 
-#define ASSERT_READ_LOCK(x) MUST_BE_READ_LOCKED(&ip_nat_lock)
-#define ASSERT_WRITE_LOCK(x) MUST_BE_WRITE_LOCKED(&ip_nat_lock)
+#define ASSERT_READ_LOCK(x)
+#define ASSERT_WRITE_LOCK(x)
 
 #include <linux/netfilter_ipv4/ip_nat.h>
 #include <linux/netfilter_ipv4/ip_nat_rule.h>
                                 : ((hooknum) == NF_IP_LOCAL_IN ? "LOCAL_IN"  \
                                    : "*ERROR*")))
 
+#ifdef CONFIG_XFRM
+static void nat_decode_session(struct sk_buff *skb, struct flowi *fl)
+{
+       struct ip_conntrack *ct;
+       struct ip_conntrack_tuple *t;
+       enum ip_conntrack_info ctinfo;
+       enum ip_conntrack_dir dir;
+       unsigned long statusbit;
+
+       ct = ip_conntrack_get(skb, &ctinfo);
+       if (ct == NULL)
+               return;
+       dir = CTINFO2DIR(ctinfo);
+       t = &ct->tuplehash[dir].tuple;
+
+       if (dir == IP_CT_DIR_ORIGINAL)
+               statusbit = IPS_DST_NAT;
+       else
+               statusbit = IPS_SRC_NAT;
+
+       if (ct->status & statusbit) {
+               fl->fl4_dst = t->dst.ip;
+               if (t->dst.protonum == IPPROTO_TCP ||
+                   t->dst.protonum == IPPROTO_UDP)
+                       fl->fl_ip_dport = t->dst.u.tcp.port;
+       }
+
+       statusbit ^= IPS_NAT_MASK;
+
+       if (ct->status & statusbit) {
+               fl->fl4_src = t->src.ip;
+               if (t->dst.protonum == IPPROTO_TCP ||
+                   t->dst.protonum == IPPROTO_UDP)
+                       fl->fl_ip_sport = t->src.u.tcp.port;
+       }
+}
+#endif
+               
 static unsigned int
 ip_nat_fn(unsigned int hooknum,
          struct sk_buff **pskb,
@@ -73,8 +111,6 @@ ip_nat_fn(unsigned int hooknum,
        IP_NF_ASSERT(!((*pskb)->nh.iph->frag_off
                       & htons(IP_MF|IP_OFFSET)));
 
-       (*pskb)->nfcache |= NFC_UNKNOWN;
-
        /* If we had a hardware checksum before, it's now invalid */
        if ((*pskb)->ip_summed == CHECKSUM_HW)
                if (skb_checksum_help(*pskb, (out == NULL)))
@@ -102,12 +138,16 @@ ip_nat_fn(unsigned int hooknum,
                return NF_ACCEPT;
        }
 
+       /* Don't try to NAT if this packet is not conntracked */
+       if (ct == &ip_conntrack_untracked)
+               return NF_ACCEPT;
+
        switch (ctinfo) {
        case IP_CT_RELATED:
        case IP_CT_RELATED+IP_CT_IS_REPLY:
                if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) {
-                       if (!icmp_reply_translation(pskb, ct, maniptype,
-                                                   CTINFO2DIR(ctinfo)))
+                       if (!ip_nat_icmp_reply_translation(pskb, ct, maniptype,
+                                                          CTINFO2DIR(ctinfo)))
                                return NF_DROP;
                        else
                                return NF_ACCEPT;
@@ -121,8 +161,12 @@ ip_nat_fn(unsigned int hooknum,
                if (!ip_nat_initialized(ct, maniptype)) {
                        unsigned int ret;
 
-                       /* LOCAL_IN hook doesn't have a chain!  */
-                       if (hooknum == NF_IP_LOCAL_IN)
+                       if (unlikely(is_confirmed(ct)))
+                               /* NAT module was loaded late */
+                               ret = alloc_null_binding_confirmed(ct, info,
+                                                                  hooknum);
+                       else if (hooknum == NF_IP_LOCAL_IN)
+                               /* LOCAL_IN hook doesn't have a chain!  */
                                ret = alloc_null_binding(ct, info, hooknum);
                        else
                                ret = ip_nat_rule_find(pskb, hooknum,
@@ -146,7 +190,7 @@ ip_nat_fn(unsigned int hooknum,
        }
 
        IP_NF_ASSERT(info);
-       return nat_packet(ct, ctinfo, hooknum, pskb);
+       return ip_nat_packet(ct, ctinfo, hooknum, pskb);
 }
 
 static unsigned int
@@ -156,16 +200,12 @@ ip_nat_in(unsigned int hooknum,
           const struct net_device *out,
           int (*okfn)(struct sk_buff *))
 {
-       u_int32_t saddr, daddr;
        unsigned int ret;
-
-       saddr = (*pskb)->nh.iph->saddr;
-       daddr = (*pskb)->nh.iph->daddr;
+       u_int32_t daddr = (*pskb)->nh.iph->daddr;
 
        ret = ip_nat_fn(hooknum, pskb, in, out, okfn);
        if (ret != NF_DROP && ret != NF_STOLEN
-           && ((*pskb)->nh.iph->saddr != saddr
-               || (*pskb)->nh.iph->daddr != daddr)) {
+           && daddr != (*pskb)->nh.iph->daddr) {
                dst_release((*pskb)->dst);
                (*pskb)->dst = NULL;
        }
@@ -179,29 +219,32 @@ ip_nat_out(unsigned int hooknum,
           const struct net_device *out,
           int (*okfn)(struct sk_buff *))
 {
+#ifdef CONFIG_XFRM
+       struct ip_conntrack *ct;
+       enum ip_conntrack_info ctinfo;
+#endif
+       unsigned int ret;
+
        /* root is playing with raw sockets. */
        if ((*pskb)->len < sizeof(struct iphdr)
            || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
                return NF_ACCEPT;
 
-       /* We can hit fragment here; forwarded packets get
-          defragmented by connection tracking coming in, then
-          fragmented (grr) by the forward code.
-
-          In future: If we have nfct != NULL, AND we have NAT
-          initialized, AND there is no helper, then we can do full
-          NAPT on the head, and IP-address-only NAT on the rest.
-
-          I'm starting to have nightmares about fragments.  */
-
-       if ((*pskb)->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) {
-               *pskb = ip_ct_gather_frags(*pskb, IP_DEFRAG_NAT_OUT);
-
-               if (!*pskb)
-                       return NF_STOLEN;
+       ret = ip_nat_fn(hooknum, pskb, in, out, okfn);
+#ifdef CONFIG_XFRM
+       if (ret != NF_DROP && ret != NF_STOLEN
+           && (ct = ip_conntrack_get(*pskb, &ctinfo)) != NULL) {
+               enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+               if (ct->tuplehash[dir].tuple.src.ip !=
+                   ct->tuplehash[!dir].tuple.dst.ip
+                   || ct->tuplehash[dir].tuple.src.u.all !=
+                      ct->tuplehash[!dir].tuple.dst.u.all
+                   )
+                       return ip_xfrm_me_harder(pskb) == 0 ? ret : NF_DROP;
        }
-
-       return ip_nat_fn(hooknum, pskb, in, out, okfn);
+#endif
+       return ret;
 }
 
 static unsigned int
@@ -211,7 +254,8 @@ ip_nat_local_fn(unsigned int hooknum,
                const struct net_device *out,
                int (*okfn)(struct sk_buff *))
 {
-       u_int32_t saddr, daddr;
+       struct ip_conntrack *ct;
+       enum ip_conntrack_info ctinfo;
        unsigned int ret;
 
        /* root is playing with raw sockets. */
@@ -219,14 +263,20 @@ ip_nat_local_fn(unsigned int hooknum,
            || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
                return NF_ACCEPT;
 
-       saddr = (*pskb)->nh.iph->saddr;
-       daddr = (*pskb)->nh.iph->daddr;
-
        ret = ip_nat_fn(hooknum, pskb, in, out, okfn);
        if (ret != NF_DROP && ret != NF_STOLEN
-           && ((*pskb)->nh.iph->saddr != saddr
-               || (*pskb)->nh.iph->daddr != daddr))
-               return ip_route_me_harder(pskb) == 0 ? ret : NF_DROP;
+           && (ct = ip_conntrack_get(*pskb, &ctinfo)) != NULL) {
+               enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+               if (ct->tuplehash[dir].tuple.dst.ip !=
+                   ct->tuplehash[!dir].tuple.src.ip
+#ifdef CONFIG_XFRM
+                   || ct->tuplehash[dir].tuple.dst.u.all !=
+                      ct->tuplehash[!dir].tuple.src.u.all
+#endif
+                   )
+                       return ip_route_me_harder(pskb) == 0 ? ret : NF_DROP;
+       }
        return ret;
 }
 
@@ -251,151 +301,100 @@ ip_nat_adjust(unsigned int hooknum,
 
 /* We must be after connection tracking and before packet filtering. */
 
-/* Before packet filtering, change destination */
-static struct nf_hook_ops ip_nat_in_ops = {
-       .hook           = ip_nat_in,
-       .owner          = THIS_MODULE,
-       .pf             = PF_INET,
-       .hooknum        = NF_IP_PRE_ROUTING,
-       .priority       = NF_IP_PRI_NAT_DST,
+static struct nf_hook_ops ip_nat_ops[] = {
+       /* Before packet filtering, change destination */
+       {
+               .hook           = ip_nat_in,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_IP_PRE_ROUTING,
+               .priority       = NF_IP_PRI_NAT_DST,
+       },
+       /* After packet filtering, change source */
+       {
+               .hook           = ip_nat_out,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_IP_POST_ROUTING,
+               .priority       = NF_IP_PRI_NAT_SRC,
+       },
+       /* After conntrack, adjust sequence number */
+       {
+               .hook           = ip_nat_adjust,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_IP_POST_ROUTING,
+               .priority       = NF_IP_PRI_NAT_SEQ_ADJUST,
+       },
+       /* Before packet filtering, change destination */
+       {
+               .hook           = ip_nat_local_fn,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_IP_LOCAL_OUT,
+               .priority       = NF_IP_PRI_NAT_DST,
+       },
+       /* After packet filtering, change source */
+       {
+               .hook           = ip_nat_fn,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_IP_LOCAL_IN,
+               .priority       = NF_IP_PRI_NAT_SRC,
+       },
+       /* After conntrack, adjust sequence number */
+       {
+               .hook           = ip_nat_adjust,
+               .owner          = THIS_MODULE,
+               .pf             = PF_INET,
+               .hooknum        = NF_IP_LOCAL_IN,
+               .priority       = NF_IP_PRI_NAT_SEQ_ADJUST,
+       },
 };
 
-/* After packet filtering, change source */
-static struct nf_hook_ops ip_nat_out_ops = {
-       .hook           = ip_nat_out,
-       .owner          = THIS_MODULE,
-       .pf             = PF_INET,
-       .hooknum        = NF_IP_POST_ROUTING,
-       .priority       = NF_IP_PRI_NAT_SRC,
-};
-
-/* After conntrack, adjust sequence number */
-static struct nf_hook_ops ip_nat_adjust_out_ops = {
-       .hook           = ip_nat_adjust,
-       .owner          = THIS_MODULE,
-       .pf             = PF_INET,
-       .hooknum        = NF_IP_POST_ROUTING,
-       .priority       = NF_IP_PRI_NAT_SEQ_ADJUST,
-};
-
-/* Before packet filtering, change destination */
-static struct nf_hook_ops ip_nat_local_out_ops = {
-       .hook           = ip_nat_local_fn,
-       .owner          = THIS_MODULE,
-       .pf             = PF_INET,
-       .hooknum        = NF_IP_LOCAL_OUT,
-       .priority       = NF_IP_PRI_NAT_DST,
-};
-
-/* After packet filtering, change source for reply packets of LOCAL_OUT DNAT */
-static struct nf_hook_ops ip_nat_local_in_ops = {
-       .hook           = ip_nat_fn,
-       .owner          = THIS_MODULE,
-       .pf             = PF_INET,
-       .hooknum        = NF_IP_LOCAL_IN,
-       .priority       = NF_IP_PRI_NAT_SRC,
-};
-
-/* After conntrack, adjust sequence number */
-static struct nf_hook_ops ip_nat_adjust_in_ops = {
-       .hook           = ip_nat_adjust,
-       .owner          = THIS_MODULE,
-       .pf             = PF_INET,
-       .hooknum        = NF_IP_LOCAL_IN,
-       .priority       = NF_IP_PRI_NAT_SEQ_ADJUST,
-};
-
-
-static int init_or_cleanup(int init)
+static int __init ip_nat_standalone_init(void)
 {
        int ret = 0;
 
-       need_ip_conntrack();
-
-       if (!init) goto cleanup;
+       need_conntrack();
 
+#ifdef CONFIG_XFRM
+       BUG_ON(ip_nat_decode_session != NULL);
+       ip_nat_decode_session = nat_decode_session;
+#endif
        ret = ip_nat_rule_init();
        if (ret < 0) {
                printk("ip_nat_init: can't setup rules.\n");
-               goto cleanup_nothing;
+               goto cleanup_decode_session;
        }
-       ret = ip_nat_init();
+       ret = nf_register_hooks(ip_nat_ops, ARRAY_SIZE(ip_nat_ops));
        if (ret < 0) {
-               printk("ip_nat_init: can't setup rules.\n");
+               printk("ip_nat_init: can't register hooks.\n");
                goto cleanup_rule_init;
        }
-       ret = nf_register_hook(&ip_nat_in_ops);
-       if (ret < 0) {
-               printk("ip_nat_init: can't register in hook.\n");
-               goto cleanup_nat;
-       }
-       ret = nf_register_hook(&ip_nat_out_ops);
-       if (ret < 0) {
-               printk("ip_nat_init: can't register out hook.\n");
-               goto cleanup_inops;
-       }
-       ret = nf_register_hook(&ip_nat_adjust_in_ops);
-       if (ret < 0) {
-               printk("ip_nat_init: can't register adjust in hook.\n");
-               goto cleanup_outops;
-       }
-       ret = nf_register_hook(&ip_nat_adjust_out_ops);
-       if (ret < 0) {
-               printk("ip_nat_init: can't register adjust out hook.\n");
-               goto cleanup_adjustin_ops;
-       }
-       ret = nf_register_hook(&ip_nat_local_out_ops);
-       if (ret < 0) {
-               printk("ip_nat_init: can't register local out hook.\n");
-               goto cleanup_adjustout_ops;;
-       }
-       ret = nf_register_hook(&ip_nat_local_in_ops);
-       if (ret < 0) {
-               printk("ip_nat_init: can't register local in hook.\n");
-               goto cleanup_localoutops;
-       }
        return ret;
 
- cleanup:
-       nf_unregister_hook(&ip_nat_local_in_ops);
- cleanup_localoutops:
-       nf_unregister_hook(&ip_nat_local_out_ops);
- cleanup_adjustout_ops:
-       nf_unregister_hook(&ip_nat_adjust_out_ops);
- cleanup_adjustin_ops:
-       nf_unregister_hook(&ip_nat_adjust_in_ops);
- cleanup_outops:
-       nf_unregister_hook(&ip_nat_out_ops);
- cleanup_inops:
-       nf_unregister_hook(&ip_nat_in_ops);
- cleanup_nat:
-       ip_nat_cleanup();
  cleanup_rule_init:
        ip_nat_rule_cleanup();
- cleanup_nothing:
-       MUST_BE_READ_WRITE_UNLOCKED(&ip_nat_lock);
+ cleanup_decode_session:
+#ifdef CONFIG_XFRM
+       ip_nat_decode_session = NULL;
+       synchronize_net();
+#endif
        return ret;
 }
 
-static int __init init(void)
+static void __exit ip_nat_standalone_fini(void)
 {
-       return init_or_cleanup(1);
+       nf_unregister_hooks(ip_nat_ops, ARRAY_SIZE(ip_nat_ops));
+       ip_nat_rule_cleanup();
+#ifdef CONFIG_XFRM
+       ip_nat_decode_session = NULL;
+       synchronize_net();
+#endif
 }
 
-static void __exit fini(void)
-{
-       init_or_cleanup(0);
-}
+module_init(ip_nat_standalone_init);
+module_exit(ip_nat_standalone_fini);
 
-module_init(init);
-module_exit(fini);
-
-EXPORT_SYMBOL(ip_nat_setup_info);
-EXPORT_SYMBOL(ip_nat_protocol_register);
-EXPORT_SYMBOL(ip_nat_protocol_unregister);
-EXPORT_SYMBOL(ip_nat_cheat_check);
-EXPORT_SYMBOL(ip_nat_mangle_tcp_packet);
-EXPORT_SYMBOL(ip_nat_mangle_udp_packet);
-EXPORT_SYMBOL(ip_nat_used_tuple);
-EXPORT_SYMBOL(ip_nat_follow_master);
 MODULE_LICENSE("GPL");