123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265 |
- /*
- * IPv6 specific functions of netfilter core
- *
- * Rusty Russell (C) 2000 -- This code is GPL.
- * Patrick McHardy (C) 2006-2012
- */
- #include <linux/kernel.h>
- #include <linux/init.h>
- #include <linux/ipv6.h>
- #include <linux/netfilter.h>
- #include <linux/netfilter_ipv6.h>
- #include <linux/export.h>
- #include <net/addrconf.h>
- #include <net/dst.h>
- #include <net/ipv6.h>
- #include <net/ip6_route.h>
- #include <net/xfrm.h>
- #include <net/netfilter/nf_queue.h>
- #include <net/netfilter/nf_conntrack_bridge.h>
- #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
- #include "../bridge/br_private.h"
- int ip6_route_me_harder(struct net *net, struct sock *sk_partial, struct sk_buff *skb)
- {
- const struct ipv6hdr *iph = ipv6_hdr(skb);
- struct sock *sk = sk_to_full_sk(sk_partial);
- unsigned int hh_len;
- struct dst_entry *dst;
- int strict = (ipv6_addr_type(&iph->daddr) &
- (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
- struct flowi6 fl6 = {
- .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if :
- strict ? skb_dst(skb)->dev->ifindex : 0,
- .flowi6_mark = skb->mark,
- .flowi6_uid = sock_net_uid(net, sk),
- .daddr = iph->daddr,
- .saddr = iph->saddr,
- };
- int err;
- dst = ip6_route_output(net, sk, &fl6);
- err = dst->error;
- if (err) {
- IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
- net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
- dst_release(dst);
- return err;
- }
- /* Drop old route. */
- skb_dst_drop(skb);
- skb_dst_set(skb, dst);
- #ifdef CONFIG_XFRM
- if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
- xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
- skb_dst_set(skb, NULL);
- dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
- if (IS_ERR(dst))
- return PTR_ERR(dst);
- skb_dst_set(skb, dst);
- }
- #endif
- /* Change in oif may mean change in hh_len. */
- hh_len = skb_dst(skb)->dev->hard_header_len;
- if (skb_headroom(skb) < hh_len &&
- pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
- 0, GFP_ATOMIC))
- return -ENOMEM;
- return 0;
- }
- EXPORT_SYMBOL(ip6_route_me_harder);
- static int nf_ip6_reroute(struct sk_buff *skb,
- const struct nf_queue_entry *entry)
- {
- struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
- if (entry->state.hook == NF_INET_LOCAL_OUT) {
- const struct ipv6hdr *iph = ipv6_hdr(skb);
- if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
- !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
- skb->mark != rt_info->mark)
- return ip6_route_me_harder(entry->state.net, entry->state.sk, skb);
- }
- return 0;
- }
- int __nf_ip6_route(struct net *net, struct dst_entry **dst,
- struct flowi *fl, bool strict)
- {
- static const struct ipv6_pinfo fake_pinfo;
- static const struct inet_sock fake_sk = {
- /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
- .sk.sk_bound_dev_if = 1,
- .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
- };
- const void *sk = strict ? &fake_sk : NULL;
- struct dst_entry *result;
- int err;
- result = ip6_route_output(net, sk, &fl->u.ip6);
- err = result->error;
- if (err)
- dst_release(result);
- else
- *dst = result;
- return err;
- }
- EXPORT_SYMBOL_GPL(__nf_ip6_route);
- int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
- struct nf_bridge_frag_data *data,
- int (*output)(struct net *, struct sock *sk,
- const struct nf_bridge_frag_data *data,
- struct sk_buff *))
- {
- int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
- ktime_t tstamp = skb->tstamp;
- struct ip6_frag_state state;
- u8 *prevhdr, nexthdr = 0;
- unsigned int mtu, hlen;
- int hroom, err = 0;
- __be32 frag_id;
- err = ip6_find_1stfragopt(skb, &prevhdr);
- if (err < 0)
- goto blackhole;
- hlen = err;
- nexthdr = *prevhdr;
- mtu = skb->dev->mtu;
- if (frag_max_size > mtu ||
- frag_max_size < IPV6_MIN_MTU)
- goto blackhole;
- mtu = frag_max_size;
- if (mtu < hlen + sizeof(struct frag_hdr) + 8)
- goto blackhole;
- mtu -= hlen + sizeof(struct frag_hdr);
- frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
- &ipv6_hdr(skb)->saddr);
- if (skb->ip_summed == CHECKSUM_PARTIAL &&
- (err = skb_checksum_help(skb)))
- goto blackhole;
- hroom = LL_RESERVED_SPACE(skb->dev);
- if (skb_has_frag_list(skb)) {
- unsigned int first_len = skb_pagelen(skb);
- struct ip6_fraglist_iter iter;
- struct sk_buff *frag2;
- if (first_len - hlen > mtu ||
- skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
- goto blackhole;
- if (skb_cloned(skb))
- goto slow_path;
- skb_walk_frags(skb, frag2) {
- if (frag2->len > mtu ||
- skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr)))
- goto blackhole;
- /* Partially cloned skb? */
- if (skb_shared(frag2))
- goto slow_path;
- }
- err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
- &iter);
- if (err < 0)
- goto blackhole;
- for (;;) {
- /* Prepare header of the next frame,
- * before previous one went down.
- */
- if (iter.frag)
- ip6_fraglist_prepare(skb, &iter);
- skb->tstamp = tstamp;
- err = output(net, sk, data, skb);
- if (err || !iter.frag)
- break;
- skb = ip6_fraglist_next(&iter);
- }
- kfree(iter.tmp_hdr);
- if (!err)
- return 0;
- kfree_skb_list(iter.frag);
- return err;
- }
- slow_path:
- /* This is a linearized skbuff, the original geometry is lost for us.
- * This may also be a clone skbuff, we could preserve the geometry for
- * the copies but probably not worth the effort.
- */
- ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom,
- LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id,
- &state);
- while (state.left > 0) {
- struct sk_buff *skb2;
- skb2 = ip6_frag_next(skb, &state);
- if (IS_ERR(skb2)) {
- err = PTR_ERR(skb2);
- goto blackhole;
- }
- skb2->tstamp = tstamp;
- err = output(net, sk, data, skb2);
- if (err)
- goto blackhole;
- }
- consume_skb(skb);
- return err;
- blackhole:
- kfree_skb(skb);
- return 0;
- }
- EXPORT_SYMBOL_GPL(br_ip6_fragment);
- static const struct nf_ipv6_ops ipv6ops = {
- #if IS_MODULE(CONFIG_IPV6)
- .chk_addr = ipv6_chk_addr,
- .route_me_harder = ip6_route_me_harder,
- .dev_get_saddr = ipv6_dev_get_saddr,
- .route = __nf_ip6_route,
- #if IS_ENABLED(CONFIG_SYN_COOKIES)
- .cookie_init_sequence = __cookie_v6_init_sequence,
- .cookie_v6_check = __cookie_v6_check,
- #endif
- #endif
- .route_input = ip6_route_input,
- .fragment = ip6_fragment,
- .reroute = nf_ip6_reroute,
- #if IS_MODULE(CONFIG_IPV6)
- .br_fragment = br_ip6_fragment,
- #endif
- };
- int __init ipv6_netfilter_init(void)
- {
- RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
- return 0;
- }
- /* This can be called from inet6_init() on errors, so it cannot
- * be marked __exit. -DaveM
- */
- void ipv6_netfilter_fini(void)
- {
- RCU_INIT_POINTER(nf_ipv6_ops, NULL);
- }
|