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![Guillaume Nault](/assets/img/avatar_default.png)
Before commitd4289fcc9b
("net: IP6 defrag: use rbtrees for IPv6 defrag"), a netperf UDP_STREAM test[0] using big IPv6 datagrams (thus generating many fragments) and running over an IPsec tunnel, reported more than 6Gbps throughput. After that patch, the same test gets only 9Mbps when receiving on a be2net nic (driver can make a big difference here, for example, ixgbe doesn't seem to be affected). By reusing the IPv4 defragmentation code, IPv6 lost fragment coalescing (IPv4 fragment coalescing was dropped by commit14fe22e334
("Revert "ipv4: use skb coalescing in defragmentation"")). Without fragment coalescing, be2net runs out of Rx ring entries and starts to drop frames (ethtool reports rx_drops_no_frags errors). Since the netperf traffic is only composed of UDP fragments, any lost packet prevents reassembly of the full datagram. Therefore, fragments which have no possibility to ever get reassembled pile up in the reassembly queue, until the memory accounting exeeds the threshold. At that point no fragment is accepted anymore, which effectively discards all netperf traffic. When reassembly timeout expires, some stale fragments are removed from the reassembly queue, so a few packets can be received, reassembled and delivered to the netperf receiver. But the nic still drops frames and soon the reassembly queue gets filled again with stale fragments. These long time frames where no datagram can be received explain why the performance drop is so significant. Re-introducing fragment coalescing is enough to get the initial performances again (6.6Gbps with be2net): driver doesn't drop frames anymore (no more rx_drops_no_frags errors) and the reassembly engine works at full speed. This patch is quite conservative and only coalesces skbs for local IPv4 and IPv6 delivery (in order to avoid changing skb geometry when forwarding). Coalescing could be extended in the future if need be, as more scenarios would probably benefit from it. [0]: Test configuration Sender: ip xfrm policy flush ip xfrm state flush ip xfrm state add src fc00:1::1 dst fc00:2::1 proto esp spi 0x1000 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:1::1 dst fc00:2::1 ip xfrm policy add src fc00:1::1 dst fc00:2::1 dir in tmpl src fc00:1::1 dst fc00:2::1 proto esp mode transport action allow ip xfrm state add src fc00:2::1 dst fc00:1::1 proto esp spi 0x1001 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:2::1 dst fc00:1::1 ip xfrm policy add src fc00:2::1 dst fc00:1::1 dir out tmpl src fc00:2::1 dst fc00:1::1 proto esp mode transport action allow netserver -D -L fc00:2::1 Receiver: ip xfrm policy flush ip xfrm state flush ip xfrm state add src fc00:2::1 dst fc00:1::1 proto esp spi 0x1001 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:2::1 dst fc00:1::1 ip xfrm policy add src fc00:2::1 dst fc00:1::1 dir in tmpl src fc00:2::1 dst fc00:1::1 proto esp mode transport action allow ip xfrm state add src fc00:1::1 dst fc00:2::1 proto esp spi 0x1000 aead 'rfc4106(gcm(aes))' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b 96 mode transport sel src fc00:1::1 dst fc00:2::1 ip xfrm policy add src fc00:1::1 dst fc00:2::1 dir out tmpl src fc00:1::1 dst fc00:2::1 proto esp mode transport action allow netperf -H fc00:2::1 -f k -P 0 -L fc00:1::1 -l 60 -t UDP_STREAM -I 99,5 -i 5,5 -T5,5 -6 Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
751 lines
18 KiB
C
751 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* The IP fragmentation functionality.
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*
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* Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
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* Alan Cox <alan@lxorguk.ukuu.org.uk>
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*
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* Fixes:
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* Alan Cox : Split from ip.c , see ip_input.c for history.
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* David S. Miller : Begin massive cleanup...
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* Andi Kleen : Add sysctls.
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* xxxx : Overlapfrag bug.
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* Ultima : ip_expire() kernel panic.
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* Bill Hawes : Frag accounting and evictor fixes.
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* John McDonald : 0 length frag bug.
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* Alexey Kuznetsov: SMP races, threading, cleanup.
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* Patrick McHardy : LRU queue of frag heads for evictor.
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*/
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#define pr_fmt(fmt) "IPv4: " fmt
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#include <linux/compiler.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/mm.h>
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#include <linux/jiffies.h>
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#include <linux/skbuff.h>
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#include <linux/list.h>
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#include <linux/ip.h>
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#include <linux/icmp.h>
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#include <linux/netdevice.h>
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#include <linux/jhash.h>
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#include <linux/random.h>
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#include <linux/slab.h>
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#include <net/route.h>
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#include <net/dst.h>
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#include <net/sock.h>
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#include <net/ip.h>
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#include <net/icmp.h>
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#include <net/checksum.h>
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#include <net/inetpeer.h>
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#include <net/inet_frag.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/inet.h>
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#include <linux/netfilter_ipv4.h>
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#include <net/inet_ecn.h>
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#include <net/l3mdev.h>
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/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
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* code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
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* as well. Or notify me, at least. --ANK
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*/
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static const char ip_frag_cache_name[] = "ip4-frags";
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/* Describe an entry in the "incomplete datagrams" queue. */
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struct ipq {
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struct inet_frag_queue q;
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u8 ecn; /* RFC3168 support */
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u16 max_df_size; /* largest frag with DF set seen */
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int iif;
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unsigned int rid;
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struct inet_peer *peer;
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};
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static u8 ip4_frag_ecn(u8 tos)
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{
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return 1 << (tos & INET_ECN_MASK);
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}
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static struct inet_frags ip4_frags;
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static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
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struct sk_buff *prev_tail, struct net_device *dev);
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static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
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{
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struct ipq *qp = container_of(q, struct ipq, q);
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struct net *net = q->fqdir->net;
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const struct frag_v4_compare_key *key = a;
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q->key.v4 = *key;
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qp->ecn = 0;
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qp->peer = q->fqdir->max_dist ?
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inet_getpeer_v4(net->ipv4.peers, key->saddr, key->vif, 1) :
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NULL;
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}
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static void ip4_frag_free(struct inet_frag_queue *q)
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{
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struct ipq *qp;
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qp = container_of(q, struct ipq, q);
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if (qp->peer)
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inet_putpeer(qp->peer);
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}
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/* Destruction primitives. */
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static void ipq_put(struct ipq *ipq)
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{
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inet_frag_put(&ipq->q);
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}
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/* Kill ipq entry. It is not destroyed immediately,
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* because caller (and someone more) holds reference count.
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*/
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static void ipq_kill(struct ipq *ipq)
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{
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inet_frag_kill(&ipq->q);
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}
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static bool frag_expire_skip_icmp(u32 user)
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{
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return user == IP_DEFRAG_AF_PACKET ||
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ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN,
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__IP_DEFRAG_CONNTRACK_IN_END) ||
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ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN,
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__IP_DEFRAG_CONNTRACK_BRIDGE_IN);
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}
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/*
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* Oops, a fragment queue timed out. Kill it and send an ICMP reply.
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*/
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static void ip_expire(struct timer_list *t)
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{
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struct inet_frag_queue *frag = from_timer(frag, t, timer);
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const struct iphdr *iph;
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struct sk_buff *head = NULL;
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struct net *net;
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struct ipq *qp;
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int err;
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qp = container_of(frag, struct ipq, q);
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net = qp->q.fqdir->net;
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rcu_read_lock();
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if (qp->q.fqdir->dead)
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goto out_rcu_unlock;
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spin_lock(&qp->q.lock);
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if (qp->q.flags & INET_FRAG_COMPLETE)
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goto out;
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ipq_kill(qp);
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__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
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__IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
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if (!(qp->q.flags & INET_FRAG_FIRST_IN))
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goto out;
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/* sk_buff::dev and sk_buff::rbnode are unionized. So we
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* pull the head out of the tree in order to be able to
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* deal with head->dev.
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*/
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head = inet_frag_pull_head(&qp->q);
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if (!head)
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goto out;
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head->dev = dev_get_by_index_rcu(net, qp->iif);
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if (!head->dev)
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goto out;
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/* skb has no dst, perform route lookup again */
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iph = ip_hdr(head);
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err = ip_route_input_noref(head, iph->daddr, iph->saddr,
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iph->tos, head->dev);
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if (err)
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goto out;
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/* Only an end host needs to send an ICMP
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* "Fragment Reassembly Timeout" message, per RFC792.
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*/
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if (frag_expire_skip_icmp(qp->q.key.v4.user) &&
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(skb_rtable(head)->rt_type != RTN_LOCAL))
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goto out;
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spin_unlock(&qp->q.lock);
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icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
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goto out_rcu_unlock;
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out:
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spin_unlock(&qp->q.lock);
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out_rcu_unlock:
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rcu_read_unlock();
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kfree_skb(head);
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ipq_put(qp);
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}
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/* Find the correct entry in the "incomplete datagrams" queue for
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* this IP datagram, and create new one, if nothing is found.
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*/
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static struct ipq *ip_find(struct net *net, struct iphdr *iph,
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u32 user, int vif)
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{
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struct frag_v4_compare_key key = {
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.saddr = iph->saddr,
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.daddr = iph->daddr,
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.user = user,
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.vif = vif,
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.id = iph->id,
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.protocol = iph->protocol,
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};
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struct inet_frag_queue *q;
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q = inet_frag_find(net->ipv4.fqdir, &key);
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if (!q)
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return NULL;
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return container_of(q, struct ipq, q);
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}
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/* Is the fragment too far ahead to be part of ipq? */
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static int ip_frag_too_far(struct ipq *qp)
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{
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struct inet_peer *peer = qp->peer;
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unsigned int max = qp->q.fqdir->max_dist;
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unsigned int start, end;
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int rc;
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if (!peer || !max)
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return 0;
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start = qp->rid;
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end = atomic_inc_return(&peer->rid);
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qp->rid = end;
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rc = qp->q.fragments_tail && (end - start) > max;
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if (rc)
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__IP_INC_STATS(qp->q.fqdir->net, IPSTATS_MIB_REASMFAILS);
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return rc;
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}
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static int ip_frag_reinit(struct ipq *qp)
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{
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unsigned int sum_truesize = 0;
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if (!mod_timer(&qp->q.timer, jiffies + qp->q.fqdir->timeout)) {
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refcount_inc(&qp->q.refcnt);
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return -ETIMEDOUT;
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}
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sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments);
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sub_frag_mem_limit(qp->q.fqdir, sum_truesize);
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qp->q.flags = 0;
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qp->q.len = 0;
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qp->q.meat = 0;
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qp->q.rb_fragments = RB_ROOT;
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qp->q.fragments_tail = NULL;
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qp->q.last_run_head = NULL;
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qp->iif = 0;
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qp->ecn = 0;
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return 0;
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}
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/* Add new segment to existing queue. */
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static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
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{
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struct net *net = qp->q.fqdir->net;
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int ihl, end, flags, offset;
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struct sk_buff *prev_tail;
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struct net_device *dev;
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unsigned int fragsize;
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int err = -ENOENT;
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u8 ecn;
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if (qp->q.flags & INET_FRAG_COMPLETE)
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goto err;
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if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
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unlikely(ip_frag_too_far(qp)) &&
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unlikely(err = ip_frag_reinit(qp))) {
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ipq_kill(qp);
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goto err;
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}
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ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
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offset = ntohs(ip_hdr(skb)->frag_off);
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flags = offset & ~IP_OFFSET;
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offset &= IP_OFFSET;
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offset <<= 3; /* offset is in 8-byte chunks */
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ihl = ip_hdrlen(skb);
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/* Determine the position of this fragment. */
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end = offset + skb->len - skb_network_offset(skb) - ihl;
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err = -EINVAL;
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/* Is this the final fragment? */
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if ((flags & IP_MF) == 0) {
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/* If we already have some bits beyond end
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* or have different end, the segment is corrupted.
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*/
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if (end < qp->q.len ||
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((qp->q.flags & INET_FRAG_LAST_IN) && end != qp->q.len))
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goto discard_qp;
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qp->q.flags |= INET_FRAG_LAST_IN;
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qp->q.len = end;
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} else {
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if (end&7) {
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end &= ~7;
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if (skb->ip_summed != CHECKSUM_UNNECESSARY)
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skb->ip_summed = CHECKSUM_NONE;
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}
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if (end > qp->q.len) {
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/* Some bits beyond end -> corruption. */
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if (qp->q.flags & INET_FRAG_LAST_IN)
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goto discard_qp;
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qp->q.len = end;
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}
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}
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if (end == offset)
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goto discard_qp;
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err = -ENOMEM;
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if (!pskb_pull(skb, skb_network_offset(skb) + ihl))
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goto discard_qp;
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err = pskb_trim_rcsum(skb, end - offset);
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if (err)
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goto discard_qp;
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/* Note : skb->rbnode and skb->dev share the same location. */
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dev = skb->dev;
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/* Makes sure compiler wont do silly aliasing games */
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barrier();
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prev_tail = qp->q.fragments_tail;
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err = inet_frag_queue_insert(&qp->q, skb, offset, end);
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if (err)
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goto insert_error;
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if (dev)
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qp->iif = dev->ifindex;
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qp->q.stamp = skb->tstamp;
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qp->q.meat += skb->len;
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qp->ecn |= ecn;
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add_frag_mem_limit(qp->q.fqdir, skb->truesize);
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if (offset == 0)
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qp->q.flags |= INET_FRAG_FIRST_IN;
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fragsize = skb->len + ihl;
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if (fragsize > qp->q.max_size)
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qp->q.max_size = fragsize;
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if (ip_hdr(skb)->frag_off & htons(IP_DF) &&
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fragsize > qp->max_df_size)
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qp->max_df_size = fragsize;
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if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
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qp->q.meat == qp->q.len) {
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unsigned long orefdst = skb->_skb_refdst;
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skb->_skb_refdst = 0UL;
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err = ip_frag_reasm(qp, skb, prev_tail, dev);
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skb->_skb_refdst = orefdst;
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if (err)
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inet_frag_kill(&qp->q);
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return err;
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}
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skb_dst_drop(skb);
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return -EINPROGRESS;
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insert_error:
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if (err == IPFRAG_DUP) {
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kfree_skb(skb);
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return -EINVAL;
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}
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err = -EINVAL;
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__IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS);
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discard_qp:
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inet_frag_kill(&qp->q);
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__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
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err:
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kfree_skb(skb);
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return err;
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}
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static bool ip_frag_coalesce_ok(const struct ipq *qp)
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{
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return qp->q.key.v4.user == IP_DEFRAG_LOCAL_DELIVER;
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}
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/* Build a new IP datagram from all its fragments. */
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static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
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struct sk_buff *prev_tail, struct net_device *dev)
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{
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struct net *net = qp->q.fqdir->net;
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struct iphdr *iph;
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void *reasm_data;
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int len, err;
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u8 ecn;
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ipq_kill(qp);
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ecn = ip_frag_ecn_table[qp->ecn];
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if (unlikely(ecn == 0xff)) {
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err = -EINVAL;
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goto out_fail;
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}
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/* Make the one we just received the head. */
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reasm_data = inet_frag_reasm_prepare(&qp->q, skb, prev_tail);
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if (!reasm_data)
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goto out_nomem;
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len = ip_hdrlen(skb) + qp->q.len;
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err = -E2BIG;
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if (len > 65535)
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goto out_oversize;
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|
|
inet_frag_reasm_finish(&qp->q, skb, reasm_data,
|
|
ip_frag_coalesce_ok(qp));
|
|
|
|
skb->dev = dev;
|
|
IPCB(skb)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
|
|
|
|
iph = ip_hdr(skb);
|
|
iph->tot_len = htons(len);
|
|
iph->tos |= ecn;
|
|
|
|
/* When we set IP_DF on a refragmented skb we must also force a
|
|
* call to ip_fragment to avoid forwarding a DF-skb of size s while
|
|
* original sender only sent fragments of size f (where f < s).
|
|
*
|
|
* We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest
|
|
* frag seen to avoid sending tiny DF-fragments in case skb was built
|
|
* from one very small df-fragment and one large non-df frag.
|
|
*/
|
|
if (qp->max_df_size == qp->q.max_size) {
|
|
IPCB(skb)->flags |= IPSKB_FRAG_PMTU;
|
|
iph->frag_off = htons(IP_DF);
|
|
} else {
|
|
iph->frag_off = 0;
|
|
}
|
|
|
|
ip_send_check(iph);
|
|
|
|
__IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
|
|
qp->q.rb_fragments = RB_ROOT;
|
|
qp->q.fragments_tail = NULL;
|
|
qp->q.last_run_head = NULL;
|
|
return 0;
|
|
|
|
out_nomem:
|
|
net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp);
|
|
err = -ENOMEM;
|
|
goto out_fail;
|
|
out_oversize:
|
|
net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->q.key.v4.saddr);
|
|
out_fail:
|
|
__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
|
|
return err;
|
|
}
|
|
|
|
/* Process an incoming IP datagram fragment. */
|
|
int ip_defrag(struct net *net, struct sk_buff *skb, u32 user)
|
|
{
|
|
struct net_device *dev = skb->dev ? : skb_dst(skb)->dev;
|
|
int vif = l3mdev_master_ifindex_rcu(dev);
|
|
struct ipq *qp;
|
|
|
|
__IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS);
|
|
skb_orphan(skb);
|
|
|
|
/* Lookup (or create) queue header */
|
|
qp = ip_find(net, ip_hdr(skb), user, vif);
|
|
if (qp) {
|
|
int ret;
|
|
|
|
spin_lock(&qp->q.lock);
|
|
|
|
ret = ip_frag_queue(qp, skb);
|
|
|
|
spin_unlock(&qp->q.lock);
|
|
ipq_put(qp);
|
|
return ret;
|
|
}
|
|
|
|
__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
|
|
kfree_skb(skb);
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL(ip_defrag);
|
|
|
|
struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
|
|
{
|
|
struct iphdr iph;
|
|
int netoff;
|
|
u32 len;
|
|
|
|
if (skb->protocol != htons(ETH_P_IP))
|
|
return skb;
|
|
|
|
netoff = skb_network_offset(skb);
|
|
|
|
if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0)
|
|
return skb;
|
|
|
|
if (iph.ihl < 5 || iph.version != 4)
|
|
return skb;
|
|
|
|
len = ntohs(iph.tot_len);
|
|
if (skb->len < netoff + len || len < (iph.ihl * 4))
|
|
return skb;
|
|
|
|
if (ip_is_fragment(&iph)) {
|
|
skb = skb_share_check(skb, GFP_ATOMIC);
|
|
if (skb) {
|
|
if (!pskb_may_pull(skb, netoff + iph.ihl * 4)) {
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
if (pskb_trim_rcsum(skb, netoff + len)) {
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
|
|
if (ip_defrag(net, skb, user))
|
|
return NULL;
|
|
skb_clear_hash(skb);
|
|
}
|
|
}
|
|
return skb;
|
|
}
|
|
EXPORT_SYMBOL(ip_check_defrag);
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static int dist_min;
|
|
|
|
static struct ctl_table ip4_frags_ns_ctl_table[] = {
|
|
{
|
|
.procname = "ipfrag_high_thresh",
|
|
.maxlen = sizeof(unsigned long),
|
|
.mode = 0644,
|
|
.proc_handler = proc_doulongvec_minmax,
|
|
},
|
|
{
|
|
.procname = "ipfrag_low_thresh",
|
|
.maxlen = sizeof(unsigned long),
|
|
.mode = 0644,
|
|
.proc_handler = proc_doulongvec_minmax,
|
|
},
|
|
{
|
|
.procname = "ipfrag_time",
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_jiffies,
|
|
},
|
|
{
|
|
.procname = "ipfrag_max_dist",
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_minmax,
|
|
.extra1 = &dist_min,
|
|
},
|
|
{ }
|
|
};
|
|
|
|
/* secret interval has been deprecated */
|
|
static int ip4_frags_secret_interval_unused;
|
|
static struct ctl_table ip4_frags_ctl_table[] = {
|
|
{
|
|
.procname = "ipfrag_secret_interval",
|
|
.data = &ip4_frags_secret_interval_unused,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec_jiffies,
|
|
},
|
|
{ }
|
|
};
|
|
|
|
static int __net_init ip4_frags_ns_ctl_register(struct net *net)
|
|
{
|
|
struct ctl_table *table;
|
|
struct ctl_table_header *hdr;
|
|
|
|
table = ip4_frags_ns_ctl_table;
|
|
if (!net_eq(net, &init_net)) {
|
|
table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
|
|
if (!table)
|
|
goto err_alloc;
|
|
|
|
}
|
|
table[0].data = &net->ipv4.fqdir->high_thresh;
|
|
table[0].extra1 = &net->ipv4.fqdir->low_thresh;
|
|
table[1].data = &net->ipv4.fqdir->low_thresh;
|
|
table[1].extra2 = &net->ipv4.fqdir->high_thresh;
|
|
table[2].data = &net->ipv4.fqdir->timeout;
|
|
table[3].data = &net->ipv4.fqdir->max_dist;
|
|
|
|
hdr = register_net_sysctl(net, "net/ipv4", table);
|
|
if (!hdr)
|
|
goto err_reg;
|
|
|
|
net->ipv4.frags_hdr = hdr;
|
|
return 0;
|
|
|
|
err_reg:
|
|
if (!net_eq(net, &init_net))
|
|
kfree(table);
|
|
err_alloc:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
|
|
{
|
|
struct ctl_table *table;
|
|
|
|
table = net->ipv4.frags_hdr->ctl_table_arg;
|
|
unregister_net_sysctl_table(net->ipv4.frags_hdr);
|
|
kfree(table);
|
|
}
|
|
|
|
static void __init ip4_frags_ctl_register(void)
|
|
{
|
|
register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table);
|
|
}
|
|
#else
|
|
static int ip4_frags_ns_ctl_register(struct net *net)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void ip4_frags_ns_ctl_unregister(struct net *net)
|
|
{
|
|
}
|
|
|
|
static void __init ip4_frags_ctl_register(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static int __net_init ipv4_frags_init_net(struct net *net)
|
|
{
|
|
int res;
|
|
|
|
res = fqdir_init(&net->ipv4.fqdir, &ip4_frags, net);
|
|
if (res < 0)
|
|
return res;
|
|
/* Fragment cache limits.
|
|
*
|
|
* The fragment memory accounting code, (tries to) account for
|
|
* the real memory usage, by measuring both the size of frag
|
|
* queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue))
|
|
* and the SKB's truesize.
|
|
*
|
|
* A 64K fragment consumes 129736 bytes (44*2944)+200
|
|
* (1500 truesize == 2944, sizeof(struct ipq) == 200)
|
|
*
|
|
* We will commit 4MB at one time. Should we cross that limit
|
|
* we will prune down to 3MB, making room for approx 8 big 64K
|
|
* fragments 8x128k.
|
|
*/
|
|
net->ipv4.fqdir->high_thresh = 4 * 1024 * 1024;
|
|
net->ipv4.fqdir->low_thresh = 3 * 1024 * 1024;
|
|
/*
|
|
* Important NOTE! Fragment queue must be destroyed before MSL expires.
|
|
* RFC791 is wrong proposing to prolongate timer each fragment arrival
|
|
* by TTL.
|
|
*/
|
|
net->ipv4.fqdir->timeout = IP_FRAG_TIME;
|
|
|
|
net->ipv4.fqdir->max_dist = 64;
|
|
|
|
res = ip4_frags_ns_ctl_register(net);
|
|
if (res < 0)
|
|
fqdir_exit(net->ipv4.fqdir);
|
|
return res;
|
|
}
|
|
|
|
static void __net_exit ipv4_frags_pre_exit_net(struct net *net)
|
|
{
|
|
fqdir_pre_exit(net->ipv4.fqdir);
|
|
}
|
|
|
|
static void __net_exit ipv4_frags_exit_net(struct net *net)
|
|
{
|
|
ip4_frags_ns_ctl_unregister(net);
|
|
fqdir_exit(net->ipv4.fqdir);
|
|
}
|
|
|
|
static struct pernet_operations ip4_frags_ops = {
|
|
.init = ipv4_frags_init_net,
|
|
.pre_exit = ipv4_frags_pre_exit_net,
|
|
.exit = ipv4_frags_exit_net,
|
|
};
|
|
|
|
|
|
static u32 ip4_key_hashfn(const void *data, u32 len, u32 seed)
|
|
{
|
|
return jhash2(data,
|
|
sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
|
|
}
|
|
|
|
static u32 ip4_obj_hashfn(const void *data, u32 len, u32 seed)
|
|
{
|
|
const struct inet_frag_queue *fq = data;
|
|
|
|
return jhash2((const u32 *)&fq->key.v4,
|
|
sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
|
|
}
|
|
|
|
static int ip4_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
|
|
{
|
|
const struct frag_v4_compare_key *key = arg->key;
|
|
const struct inet_frag_queue *fq = ptr;
|
|
|
|
return !!memcmp(&fq->key, key, sizeof(*key));
|
|
}
|
|
|
|
static const struct rhashtable_params ip4_rhash_params = {
|
|
.head_offset = offsetof(struct inet_frag_queue, node),
|
|
.key_offset = offsetof(struct inet_frag_queue, key),
|
|
.key_len = sizeof(struct frag_v4_compare_key),
|
|
.hashfn = ip4_key_hashfn,
|
|
.obj_hashfn = ip4_obj_hashfn,
|
|
.obj_cmpfn = ip4_obj_cmpfn,
|
|
.automatic_shrinking = true,
|
|
};
|
|
|
|
void __init ipfrag_init(void)
|
|
{
|
|
ip4_frags.constructor = ip4_frag_init;
|
|
ip4_frags.destructor = ip4_frag_free;
|
|
ip4_frags.qsize = sizeof(struct ipq);
|
|
ip4_frags.frag_expire = ip_expire;
|
|
ip4_frags.frags_cache_name = ip_frag_cache_name;
|
|
ip4_frags.rhash_params = ip4_rhash_params;
|
|
if (inet_frags_init(&ip4_frags))
|
|
panic("IP: failed to allocate ip4_frags cache\n");
|
|
ip4_frags_ctl_register();
|
|
register_pernet_subsys(&ip4_frags_ops);
|
|
}
|