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267 lines
6.6 KiB
267 lines
6.6 KiB
/* |
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* IPv6 specific functions of netfilter core |
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* |
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* Rusty Russell (C) 2000 -- This code is GPL. |
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* Patrick McHardy (C) 2006-2012 |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/init.h> |
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#include <linux/ipv6.h> |
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#include <linux/netfilter.h> |
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#include <linux/netfilter_ipv6.h> |
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#include <linux/export.h> |
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#include <net/addrconf.h> |
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#include <net/dst.h> |
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#include <net/ipv6.h> |
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#include <net/ip6_route.h> |
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#include <net/xfrm.h> |
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#include <net/netfilter/nf_queue.h> |
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#include <net/netfilter/nf_conntrack_bridge.h> |
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#include <net/netfilter/ipv6/nf_defrag_ipv6.h> |
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#include "../bridge/br_private.h" |
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int ip6_route_me_harder(struct net *net, struct sock *sk_partial, struct sk_buff *skb) |
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{ |
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const struct ipv6hdr *iph = ipv6_hdr(skb); |
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struct sock *sk = sk_to_full_sk(sk_partial); |
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struct flow_keys flkeys; |
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unsigned int hh_len; |
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struct dst_entry *dst; |
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int strict = (ipv6_addr_type(&iph->daddr) & |
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(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); |
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struct flowi6 fl6 = { |
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.flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if : |
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strict ? skb_dst(skb)->dev->ifindex : 0, |
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.flowi6_mark = skb->mark, |
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.flowi6_uid = sock_net_uid(net, sk), |
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.daddr = iph->daddr, |
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.saddr = iph->saddr, |
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}; |
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int err; |
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fib6_rules_early_flow_dissect(net, skb, &fl6, &flkeys); |
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dst = ip6_route_output(net, sk, &fl6); |
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err = dst->error; |
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if (err) { |
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IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); |
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net_dbg_ratelimited("ip6_route_me_harder: No more route\n"); |
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dst_release(dst); |
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return err; |
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} |
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/* Drop old route. */ |
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skb_dst_drop(skb); |
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skb_dst_set(skb, dst); |
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#ifdef CONFIG_XFRM |
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if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && |
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xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) { |
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skb_dst_set(skb, NULL); |
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dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); |
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if (IS_ERR(dst)) |
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return PTR_ERR(dst); |
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skb_dst_set(skb, dst); |
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} |
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#endif |
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/* Change in oif may mean change in hh_len. */ |
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hh_len = skb_dst(skb)->dev->hard_header_len; |
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if (skb_headroom(skb) < hh_len && |
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pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)), |
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0, GFP_ATOMIC)) |
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return -ENOMEM; |
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return 0; |
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} |
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EXPORT_SYMBOL(ip6_route_me_harder); |
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static int nf_ip6_reroute(struct sk_buff *skb, |
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const struct nf_queue_entry *entry) |
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{ |
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struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); |
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if (entry->state.hook == NF_INET_LOCAL_OUT) { |
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const struct ipv6hdr *iph = ipv6_hdr(skb); |
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if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || |
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!ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || |
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skb->mark != rt_info->mark) |
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return ip6_route_me_harder(entry->state.net, entry->state.sk, skb); |
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} |
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return 0; |
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} |
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int __nf_ip6_route(struct net *net, struct dst_entry **dst, |
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struct flowi *fl, bool strict) |
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{ |
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static const struct ipv6_pinfo fake_pinfo; |
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static const struct inet_sock fake_sk = { |
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/* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */ |
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.sk.sk_bound_dev_if = 1, |
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.pinet6 = (struct ipv6_pinfo *) &fake_pinfo, |
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}; |
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const void *sk = strict ? &fake_sk : NULL; |
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struct dst_entry *result; |
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int err; |
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result = ip6_route_output(net, sk, &fl->u.ip6); |
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err = result->error; |
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if (err) |
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dst_release(result); |
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else |
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*dst = result; |
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return err; |
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} |
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EXPORT_SYMBOL_GPL(__nf_ip6_route); |
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int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
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struct nf_bridge_frag_data *data, |
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int (*output)(struct net *, struct sock *sk, |
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const struct nf_bridge_frag_data *data, |
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struct sk_buff *)) |
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{ |
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int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; |
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ktime_t tstamp = skb->tstamp; |
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struct ip6_frag_state state; |
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u8 *prevhdr, nexthdr = 0; |
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unsigned int mtu, hlen; |
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int hroom, err = 0; |
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__be32 frag_id; |
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err = ip6_find_1stfragopt(skb, &prevhdr); |
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if (err < 0) |
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goto blackhole; |
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hlen = err; |
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nexthdr = *prevhdr; |
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mtu = skb->dev->mtu; |
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if (frag_max_size > mtu || |
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frag_max_size < IPV6_MIN_MTU) |
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goto blackhole; |
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mtu = frag_max_size; |
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if (mtu < hlen + sizeof(struct frag_hdr) + 8) |
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goto blackhole; |
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mtu -= hlen + sizeof(struct frag_hdr); |
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frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, |
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&ipv6_hdr(skb)->saddr); |
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if (skb->ip_summed == CHECKSUM_PARTIAL && |
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(err = skb_checksum_help(skb))) |
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goto blackhole; |
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hroom = LL_RESERVED_SPACE(skb->dev); |
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if (skb_has_frag_list(skb)) { |
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unsigned int first_len = skb_pagelen(skb); |
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struct ip6_fraglist_iter iter; |
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struct sk_buff *frag2; |
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if (first_len - hlen > mtu || |
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skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) |
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goto blackhole; |
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if (skb_cloned(skb)) |
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goto slow_path; |
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skb_walk_frags(skb, frag2) { |
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if (frag2->len > mtu || |
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skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr))) |
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goto blackhole; |
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/* Partially cloned skb? */ |
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if (skb_shared(frag2)) |
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goto slow_path; |
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} |
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err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, |
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&iter); |
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if (err < 0) |
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goto blackhole; |
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for (;;) { |
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/* Prepare header of the next frame, |
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* before previous one went down. |
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*/ |
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if (iter.frag) |
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ip6_fraglist_prepare(skb, &iter); |
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skb->tstamp = tstamp; |
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err = output(net, sk, data, skb); |
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if (err || !iter.frag) |
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break; |
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skb = ip6_fraglist_next(&iter); |
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} |
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kfree(iter.tmp_hdr); |
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if (!err) |
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return 0; |
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kfree_skb_list(iter.frag); |
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return err; |
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} |
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slow_path: |
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/* This is a linearized skbuff, the original geometry is lost for us. |
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* This may also be a clone skbuff, we could preserve the geometry for |
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* the copies but probably not worth the effort. |
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*/ |
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ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom, |
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LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id, |
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&state); |
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while (state.left > 0) { |
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struct sk_buff *skb2; |
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skb2 = ip6_frag_next(skb, &state); |
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if (IS_ERR(skb2)) { |
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err = PTR_ERR(skb2); |
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goto blackhole; |
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} |
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skb2->tstamp = tstamp; |
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err = output(net, sk, data, skb2); |
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if (err) |
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goto blackhole; |
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} |
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consume_skb(skb); |
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return err; |
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blackhole: |
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kfree_skb(skb); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(br_ip6_fragment); |
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static const struct nf_ipv6_ops ipv6ops = { |
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#if IS_MODULE(CONFIG_IPV6) |
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.chk_addr = ipv6_chk_addr, |
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.route_me_harder = ip6_route_me_harder, |
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.dev_get_saddr = ipv6_dev_get_saddr, |
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.route = __nf_ip6_route, |
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#if IS_ENABLED(CONFIG_SYN_COOKIES) |
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.cookie_init_sequence = __cookie_v6_init_sequence, |
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.cookie_v6_check = __cookie_v6_check, |
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#endif |
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#endif |
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.route_input = ip6_route_input, |
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.fragment = ip6_fragment, |
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.reroute = nf_ip6_reroute, |
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#if IS_MODULE(CONFIG_IPV6) |
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.br_fragment = br_ip6_fragment, |
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#endif |
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}; |
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int __init ipv6_netfilter_init(void) |
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{ |
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RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops); |
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return 0; |
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} |
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/* This can be called from inet6_init() on errors, so it cannot |
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* be marked __exit. -DaveM |
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*/ |
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void ipv6_netfilter_fini(void) |
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{ |
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RCU_INIT_POINTER(nf_ipv6_ops, NULL); |
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}
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