diff options
Diffstat (limited to '')
-rw-r--r-- | net/ipv4/netfilter/nf_nat_l3proto_ipv4.c | 388 |
1 files changed, 0 insertions, 388 deletions
diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c deleted file mode 100644 index fa2ba7c500e4..000000000000 --- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c +++ /dev/null @@ -1,388 +0,0 @@ -/* - * (C) 1999-2001 Paul `Rusty' Russell - * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> - * (C) 2011 Patrick McHardy <kaber@trash.net> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <linux/types.h> -#include <linux/module.h> -#include <linux/skbuff.h> -#include <linux/ip.h> -#include <linux/icmp.h> -#include <linux/netfilter.h> -#include <linux/netfilter_ipv4.h> -#include <net/secure_seq.h> -#include <net/checksum.h> -#include <net/route.h> -#include <net/ip.h> - -#include <net/netfilter/nf_conntrack_core.h> -#include <net/netfilter/nf_conntrack.h> -#include <net/netfilter/nf_nat_core.h> -#include <net/netfilter/nf_nat_l3proto.h> -#include <net/netfilter/nf_nat_l4proto.h> - -static const struct nf_nat_l3proto nf_nat_l3proto_ipv4; - -#ifdef CONFIG_XFRM -static void nf_nat_ipv4_decode_session(struct sk_buff *skb, - const struct nf_conn *ct, - enum ip_conntrack_dir dir, - unsigned long statusbit, - struct flowi *fl) -{ - const struct nf_conntrack_tuple *t = &ct->tuplehash[dir].tuple; - struct flowi4 *fl4 = &fl->u.ip4; - - if (ct->status & statusbit) { - fl4->daddr = t->dst.u3.ip; - if (t->dst.protonum == IPPROTO_TCP || - t->dst.protonum == IPPROTO_UDP || - t->dst.protonum == IPPROTO_UDPLITE || - t->dst.protonum == IPPROTO_DCCP || - t->dst.protonum == IPPROTO_SCTP) - fl4->fl4_dport = t->dst.u.all; - } - - statusbit ^= IPS_NAT_MASK; - - if (ct->status & statusbit) { - fl4->saddr = t->src.u3.ip; - if (t->dst.protonum == IPPROTO_TCP || - t->dst.protonum == IPPROTO_UDP || - t->dst.protonum == IPPROTO_UDPLITE || - t->dst.protonum == IPPROTO_DCCP || - t->dst.protonum == IPPROTO_SCTP) - fl4->fl4_sport = t->src.u.all; - } -} -#endif /* CONFIG_XFRM */ - -static bool nf_nat_ipv4_manip_pkt(struct sk_buff *skb, - unsigned int iphdroff, - const struct nf_conntrack_tuple *target, - enum nf_nat_manip_type maniptype) -{ - struct iphdr *iph; - unsigned int hdroff; - - if (!skb_make_writable(skb, iphdroff + sizeof(*iph))) - return false; - - iph = (void *)skb->data + iphdroff; - hdroff = iphdroff + iph->ihl * 4; - - if (!nf_nat_l4proto_manip_pkt(skb, &nf_nat_l3proto_ipv4, iphdroff, - hdroff, target, maniptype)) - return false; - iph = (void *)skb->data + iphdroff; - - if (maniptype == NF_NAT_MANIP_SRC) { - csum_replace4(&iph->check, iph->saddr, target->src.u3.ip); - iph->saddr = target->src.u3.ip; - } else { - csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip); - iph->daddr = target->dst.u3.ip; - } - return true; -} - -static void nf_nat_ipv4_csum_update(struct sk_buff *skb, - unsigned int iphdroff, __sum16 *check, - const struct nf_conntrack_tuple *t, - enum nf_nat_manip_type maniptype) -{ - struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff); - __be32 oldip, newip; - - if (maniptype == NF_NAT_MANIP_SRC) { - oldip = iph->saddr; - newip = t->src.u3.ip; - } else { - oldip = iph->daddr; - newip = t->dst.u3.ip; - } - inet_proto_csum_replace4(check, skb, oldip, newip, true); -} - -static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, - u8 proto, void *data, __sum16 *check, - int datalen, int oldlen) -{ - if (skb->ip_summed != CHECKSUM_PARTIAL) { - const struct iphdr *iph = ip_hdr(skb); - - skb->ip_summed = CHECKSUM_PARTIAL; - skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + - ip_hdrlen(skb); - skb->csum_offset = (void *)check - data; - *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, - proto, 0); - } else - inet_proto_csum_replace2(check, skb, - htons(oldlen), htons(datalen), true); -} - -#if IS_ENABLED(CONFIG_NF_CT_NETLINK) -static int nf_nat_ipv4_nlattr_to_range(struct nlattr *tb[], - struct nf_nat_range2 *range) -{ - if (tb[CTA_NAT_V4_MINIP]) { - range->min_addr.ip = nla_get_be32(tb[CTA_NAT_V4_MINIP]); - range->flags |= NF_NAT_RANGE_MAP_IPS; - } - - if (tb[CTA_NAT_V4_MAXIP]) - range->max_addr.ip = nla_get_be32(tb[CTA_NAT_V4_MAXIP]); - else - range->max_addr.ip = range->min_addr.ip; - - return 0; -} -#endif - -static const struct nf_nat_l3proto nf_nat_l3proto_ipv4 = { - .l3proto = NFPROTO_IPV4, - .manip_pkt = nf_nat_ipv4_manip_pkt, - .csum_update = nf_nat_ipv4_csum_update, - .csum_recalc = nf_nat_ipv4_csum_recalc, -#if IS_ENABLED(CONFIG_NF_CT_NETLINK) - .nlattr_to_range = nf_nat_ipv4_nlattr_to_range, -#endif -#ifdef CONFIG_XFRM - .decode_session = nf_nat_ipv4_decode_session, -#endif -}; - -int nf_nat_icmp_reply_translation(struct sk_buff *skb, - struct nf_conn *ct, - enum ip_conntrack_info ctinfo, - unsigned int hooknum) -{ - struct { - struct icmphdr icmp; - struct iphdr ip; - } *inside; - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); - unsigned int hdrlen = ip_hdrlen(skb); - struct nf_conntrack_tuple target; - unsigned long statusbit; - - WARN_ON(ctinfo != IP_CT_RELATED && ctinfo != IP_CT_RELATED_REPLY); - - if (!skb_make_writable(skb, hdrlen + sizeof(*inside))) - return 0; - if (nf_ip_checksum(skb, hooknum, hdrlen, 0)) - return 0; - - inside = (void *)skb->data + hdrlen; - if (inside->icmp.type == ICMP_REDIRECT) { - if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK) - return 0; - if (ct->status & IPS_NAT_MASK) - return 0; - } - - if (manip == NF_NAT_MANIP_SRC) - statusbit = IPS_SRC_NAT; - else - statusbit = IPS_DST_NAT; - - /* Invert if this is reply direction */ - if (dir == IP_CT_DIR_REPLY) - statusbit ^= IPS_NAT_MASK; - - if (!(ct->status & statusbit)) - return 1; - - if (!nf_nat_ipv4_manip_pkt(skb, hdrlen + sizeof(inside->icmp), - &ct->tuplehash[!dir].tuple, !manip)) - return 0; - - if (skb->ip_summed != CHECKSUM_PARTIAL) { - /* Reloading "inside" here since manip_pkt may reallocate */ - inside = (void *)skb->data + hdrlen; - inside->icmp.checksum = 0; - inside->icmp.checksum = - csum_fold(skb_checksum(skb, hdrlen, - skb->len - hdrlen, 0)); - } - - /* Change outer to look like the reply to an incoming packet */ - nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); - target.dst.protonum = IPPROTO_ICMP; - if (!nf_nat_ipv4_manip_pkt(skb, 0, &target, manip)) - return 0; - - return 1; -} -EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); - -static unsigned int -nf_nat_ipv4_fn(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ - struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - - ct = nf_ct_get(skb, &ctinfo); - if (!ct) - return NF_ACCEPT; - - if (ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED_REPLY) { - if (ip_hdr(skb)->protocol == IPPROTO_ICMP) { - if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, - state->hook)) - return NF_DROP; - else - return NF_ACCEPT; - } - } - - return nf_nat_inet_fn(priv, skb, state); -} - -static unsigned int -nf_nat_ipv4_in(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ - unsigned int ret; - __be32 daddr = ip_hdr(skb)->daddr; - - ret = nf_nat_ipv4_fn(priv, skb, state); - if (ret != NF_DROP && ret != NF_STOLEN && - daddr != ip_hdr(skb)->daddr) - skb_dst_drop(skb); - - return ret; -} - -static unsigned int -nf_nat_ipv4_out(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ -#ifdef CONFIG_XFRM - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - int err; -#endif - unsigned int ret; - - ret = nf_nat_ipv4_fn(priv, skb, state); -#ifdef CONFIG_XFRM - if (ret != NF_DROP && ret != NF_STOLEN && - !(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if ((ct->tuplehash[dir].tuple.src.u3.ip != - ct->tuplehash[!dir].tuple.dst.u3.ip) || - (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && - ct->tuplehash[dir].tuple.src.u.all != - ct->tuplehash[!dir].tuple.dst.u.all)) { - err = nf_xfrm_me_harder(state->net, skb, AF_INET); - if (err < 0) - ret = NF_DROP_ERR(err); - } - } -#endif - return ret; -} - -static unsigned int -nf_nat_ipv4_local_fn(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - unsigned int ret; - int err; - - ret = nf_nat_ipv4_fn(priv, skb, state); - if (ret != NF_DROP && ret != NF_STOLEN && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if (ct->tuplehash[dir].tuple.dst.u3.ip != - ct->tuplehash[!dir].tuple.src.u3.ip) { - err = ip_route_me_harder(state->net, skb, RTN_UNSPEC); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#ifdef CONFIG_XFRM - else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && - ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && - ct->tuplehash[dir].tuple.dst.u.all != - ct->tuplehash[!dir].tuple.src.u.all) { - err = nf_xfrm_me_harder(state->net, skb, AF_INET); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#endif - } - return ret; -} - -static const struct nf_hook_ops nf_nat_ipv4_ops[] = { - /* Before packet filtering, change destination */ - { - .hook = nf_nat_ipv4_in, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_PRE_ROUTING, - .priority = NF_IP_PRI_NAT_DST, - }, - /* After packet filtering, change source */ - { - .hook = nf_nat_ipv4_out, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_POST_ROUTING, - .priority = NF_IP_PRI_NAT_SRC, - }, - /* Before packet filtering, change destination */ - { - .hook = nf_nat_ipv4_local_fn, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_LOCAL_OUT, - .priority = NF_IP_PRI_NAT_DST, - }, - /* After packet filtering, change source */ - { - .hook = nf_nat_ipv4_fn, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_LOCAL_IN, - .priority = NF_IP_PRI_NAT_SRC, - }, -}; - -int nf_nat_l3proto_ipv4_register_fn(struct net *net, const struct nf_hook_ops *ops) -{ - return nf_nat_register_fn(net, ops, nf_nat_ipv4_ops, ARRAY_SIZE(nf_nat_ipv4_ops)); -} -EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv4_register_fn); - -void nf_nat_l3proto_ipv4_unregister_fn(struct net *net, const struct nf_hook_ops *ops) -{ - nf_nat_unregister_fn(net, ops, ARRAY_SIZE(nf_nat_ipv4_ops)); -} -EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv4_unregister_fn); - -static int __init nf_nat_l3proto_ipv4_init(void) -{ - return nf_nat_l3proto_register(&nf_nat_l3proto_ipv4); -} - -static void __exit nf_nat_l3proto_ipv4_exit(void) -{ - nf_nat_l3proto_unregister(&nf_nat_l3proto_ipv4); -} - -MODULE_LICENSE("GPL"); -MODULE_ALIAS("nf-nat-" __stringify(AF_INET)); - -module_init(nf_nat_l3proto_ipv4_init); -module_exit(nf_nat_l3proto_ipv4_exit); |