linux/net/ipv6/reassembly.c

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/*
* IPv6 fragment reassembly
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
*
* Based on: net/ipv4/ip_fragment.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
/*
* Fixes:
* Andi Kleen Make it work with multiple hosts.
* More RFC compliance.
*
* Horst von Brand Add missing #include <linux/string.h>
* Alexey Kuznetsov SMP races, threading, cleanup.
* Patrick McHardy LRU queue of frag heads for evictor.
* Mitsuru KANDA @USAGI Register inet6_protocol{}.
* David Stevens and
* YOSHIFUJI,H. @USAGI Always remove fragment header to
* calculate ICV correctly.
*/
#define pr_fmt(fmt) "IPv6: " fmt
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/jiffies.h>
#include <linux/net.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/in6.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/random.h>
#include <linux/jhash.h>
#include <linux/skbuff.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/rawv6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/ipv6_frag.h>
#include <net/inet_ecn.h>
static const char ip6_frag_cache_name[] = "ip6-frags";
static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
{
return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
}
static struct inet_frags ip6_frags;
static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
struct sk_buff *prev_tail, struct net_device *dev);
static void ip6_frag_expire(struct timer_list *t)
{
struct inet_frag_queue *frag = from_timer(frag, t, timer);
struct frag_queue *fq;
struct net *net;
fq = container_of(frag, struct frag_queue, q);
net = container_of(fq->q.fqdir, struct net, ipv6.fqdir);
ip6frag_expire_frag_queue(net, fq);
}
static struct frag_queue *
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
fq_find(struct net *net, __be32 id, const struct ipv6hdr *hdr, int iif)
{
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
struct frag_v6_compare_key key = {
.id = id,
.saddr = hdr->saddr,
.daddr = hdr->daddr,
.user = IP6_DEFRAG_LOCAL_DELIVER,
.iif = iif,
};
struct inet_frag_queue *q;
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
if (!(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_MULTICAST |
IPV6_ADDR_LINKLOCAL)))
key.iif = 0;
q = inet_frag_find(&net->ipv6.fqdir, &key);
if (!q)
return NULL;
return container_of(q, struct frag_queue, q);
}
static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
struct frag_hdr *fhdr, int nhoff,
u32 *prob_offset)
{
struct net *net = dev_net(skb_dst(skb)->dev);
int offset, end, fragsize;
struct sk_buff *prev_tail;
struct net_device *dev;
int err = -ENOENT;
u8 ecn;
if (fq->q.flags & INET_FRAG_COMPLETE)
goto err;
err = -EINVAL;
offset = ntohs(fhdr->frag_off) & ~0x7;
end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
if ((unsigned int)end > IPV6_MAXPLEN) {
*prob_offset = (u8 *)&fhdr->frag_off - skb_network_header(skb);
/* note that if prob_offset is set, the skb is freed elsewhere,
* we do not free it here.
*/
return -1;
}
ecn = ip6_frag_ecn(ipv6_hdr(skb));
if (skb->ip_summed == CHECKSUM_COMPLETE) {
const unsigned char *nh = skb_network_header(skb);
skb->csum = csum_sub(skb->csum,
csum_partial(nh, (u8 *)(fhdr + 1) - nh,
0));
}
/* Is this the final fragment? */
if (!(fhdr->frag_off & htons(IP6_MF))) {
/* If we already have some bits beyond end
* or have different end, the segment is corrupted.
*/
if (end < fq->q.len ||
((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len))
goto discard_fq;
fq->q.flags |= INET_FRAG_LAST_IN;
fq->q.len = end;
} else {
/* Check if the fragment is rounded to 8 bytes.
* Required by the RFC.
*/
if (end & 0x7) {
/* RFC2460 says always send parameter problem in
* this case. -DaveM
*/
*prob_offset = offsetof(struct ipv6hdr, payload_len);
return -1;
}
if (end > fq->q.len) {
/* Some bits beyond end -> corruption. */
if (fq->q.flags & INET_FRAG_LAST_IN)
goto discard_fq;
fq->q.len = end;
}
}
if (end == offset)
goto discard_fq;
err = -ENOMEM;
/* Point into the IP datagram 'data' part. */
if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
goto discard_fq;
err = pskb_trim_rcsum(skb, end - offset);
if (err)
goto discard_fq;
/* Note : skb->rbnode and skb->dev share the same location. */
dev = skb->dev;
/* Makes sure compiler wont do silly aliasing games */
barrier();
prev_tail = fq->q.fragments_tail;
err = inet_frag_queue_insert(&fq->q, skb, offset, end);
if (err)
goto insert_error;
if (dev)
fq->iif = dev->ifindex;
fq->q.stamp = skb->tstamp;
fq->q.meat += skb->len;
fq->ecn |= ecn;
add_frag_mem_limit(fq->q.fqdir, skb->truesize);
fragsize = -skb_network_offset(skb) + skb->len;
if (fragsize > fq->q.max_size)
fq->q.max_size = fragsize;
/* The first fragment.
* nhoffset is obtained from the first fragment, of course.
*/
if (offset == 0) {
fq->nhoffset = nhoff;
fq->q.flags |= INET_FRAG_FIRST_IN;
}
if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
fq->q.meat == fq->q.len) {
unsigned long orefdst = skb->_skb_refdst;
skb->_skb_refdst = 0UL;
err = ip6_frag_reasm(fq, skb, prev_tail, dev);
skb->_skb_refdst = orefdst;
return err;
}
skb_dst_drop(skb);
return -EINPROGRESS;
insert_error:
if (err == IPFRAG_DUP) {
kfree_skb(skb);
return -EINVAL;
}
err = -EINVAL;
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_REASM_OVERLAPS);
discard_fq:
inet_frag_kill(&fq->q);
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_REASMFAILS);
err:
kfree_skb(skb);
return err;
}
/*
* Check if this packet is complete.
*
* It is called with locked fq, and caller must check that
* queue is eligible for reassembly i.e. it is not COMPLETE,
* the last and the first frames arrived and all the bits are here.
*/
static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
struct sk_buff *prev_tail, struct net_device *dev)
{
struct net *net = container_of(fq->q.fqdir, struct net, ipv6.fqdir);
unsigned int nhoff;
void *reasm_data;
int payload_len;
u8 ecn;
inet_frag_kill(&fq->q);
ecn = ip_frag_ecn_table[fq->ecn];
if (unlikely(ecn == 0xff))
goto out_fail;
reasm_data = inet_frag_reasm_prepare(&fq->q, skb, prev_tail);
if (!reasm_data)
goto out_oom;
payload_len = ((skb->data - skb_network_header(skb)) -
sizeof(struct ipv6hdr) + fq->q.len -
sizeof(struct frag_hdr));
if (payload_len > IPV6_MAXPLEN)
goto out_oversize;
/* We have to remove fragment header from datagram and to relocate
* header in order to calculate ICV correctly. */
nhoff = fq->nhoffset;
skb_network_header(skb)[nhoff] = skb_transport_header(skb)[0];
memmove(skb->head + sizeof(struct frag_hdr), skb->head,
(skb->data - skb->head) - sizeof(struct frag_hdr));
if (skb_mac_header_was_set(skb))
skb->mac_header += sizeof(struct frag_hdr);
skb->network_header += sizeof(struct frag_hdr);
skb_reset_transport_header(skb);
inet_frag_reasm_finish(&fq->q, skb, reasm_data);
skb->dev = dev;
ipv6_hdr(skb)->payload_len = htons(payload_len);
ipv6_change_dsfield(ipv6_hdr(skb), 0xff, ecn);
IP6CB(skb)->nhoff = nhoff;
IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
IP6CB(skb)->frag_max_size = fq->q.max_size;
/* Yes, and fold redundant checksum back. 8) */
skb_postpush_rcsum(skb, skb_network_header(skb),
skb_network_header_len(skb));
rcu_read_lock();
__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
rcu_read_unlock();
fq->q.rb_fragments = RB_ROOT;
fq->q.fragments_tail = NULL;
fq->q.last_run_head = NULL;
return 1;
out_oversize:
net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len);
goto out_fail;
out_oom:
net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n");
out_fail:
rcu_read_lock();
__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
rcu_read_unlock();
inet_frag_kill(&fq->q);
return -1;
}
static int ipv6_frag_rcv(struct sk_buff *skb)
{
struct frag_hdr *fhdr;
struct frag_queue *fq;
const struct ipv6hdr *hdr = ipv6_hdr(skb);
struct net *net = dev_net(skb_dst(skb)->dev);
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
int iif;
if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
goto fail_hdr;
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
/* Jumbo payload inhibits frag. header */
if (hdr->payload_len == 0)
goto fail_hdr;
if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
sizeof(struct frag_hdr))))
goto fail_hdr;
hdr = ipv6_hdr(skb);
fhdr = (struct frag_hdr *)skb_transport_header(skb);
if (!(fhdr->frag_off & htons(0xFFF9))) {
/* It is not a fragmented frame */
skb->transport_header += sizeof(struct frag_hdr);
__IP6_INC_STATS(net,
ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
return 1;
}
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
iif = skb->dev ? skb->dev->ifindex : 0;
fq = fq_find(net, fhdr->identification, hdr, iif);
if (fq) {
u32 prob_offset = 0;
int ret;
spin_lock(&fq->q.lock);
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
fq->iif = iif;
ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff,
&prob_offset);
spin_unlock(&fq->q.lock);
inet_frag_put(&fq->q);
if (prob_offset) {
__IP6_INC_STATS(net, __in6_dev_get_safely(skb->dev),
IPSTATS_MIB_INHDRERRORS);
/* icmpv6_param_prob() calls kfree_skb(skb) */
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, prob_offset);
}
return ret;
}
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
kfree_skb(skb);
return -1;
fail_hdr:
__IP6_INC_STATS(net, __in6_dev_get_safely(skb->dev),
IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
return -1;
}
static const struct inet6_protocol frag_protocol = {
.handler = ipv6_frag_rcv,
.flags = INET6_PROTO_NOPOLICY,
};
#ifdef CONFIG_SYSCTL
static struct ctl_table ip6_frags_ns_ctl_table[] = {
{
.procname = "ip6frag_high_thresh",
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
{
.procname = "ip6frag_low_thresh",
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
},
{
.procname = "ip6frag_time",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{ }
};
/* secret interval has been deprecated */
static int ip6_frags_secret_interval_unused;
static struct ctl_table ip6_frags_ctl_table[] = {
{
.procname = "ip6frag_secret_interval",
.data = &ip6_frags_secret_interval_unused,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{ }
};
static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
{
struct ctl_table *table;
struct ctl_table_header *hdr;
table = ip6_frags_ns_ctl_table;
if (!net_eq(net, &init_net)) {
table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
if (!table)
goto err_alloc;
}
table[0].data = &net->ipv6.fqdir.high_thresh;
table[0].extra1 = &net->ipv6.fqdir.low_thresh;
table[1].data = &net->ipv6.fqdir.low_thresh;
table[1].extra2 = &net->ipv6.fqdir.high_thresh;
table[2].data = &net->ipv6.fqdir.timeout;
hdr = register_net_sysctl(net, "net/ipv6", table);
if (!hdr)
goto err_reg;
net->ipv6.sysctl.frags_hdr = hdr;
return 0;
err_reg:
if (!net_eq(net, &init_net))
kfree(table);
err_alloc:
return -ENOMEM;
}
static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
{
struct ctl_table *table;
table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
ipv6: fix an oops when force unload ipv6 module When I do an ipv6 module force unload,I got the following oops: #rmmod -f ipv6 ------------[ cut here ]------------ kernel BUG at mm/slub.c:2969! invalid opcode: 0000 [#1] SMP last sysfs file: /sys/devices/pci0000:00/0000:00:11.0/0000:02:03.0/net/eth2/ifindex Modules linked in: ipv6(-) dm_multipath uinput ppdev tpm_tis tpm tpm_bios pcspkr pcnet32 mii parport_pc i2c_piix4 parport i2c_core floppy mptspi mptscsih mptbase scsi_transport_spi Pid: 2530, comm: rmmod Tainted: G R 2.6.32 #2 440BX Desktop Reference Platform/VMware Virtual Platform EIP: 0060:[<c04b73f2>] EFLAGS: 00010246 CPU: 0 EIP is at kfree+0x6a/0xdd EAX: 00000000 EBX: c09e86bc ECX: c043e4dd EDX: c14293e0 ESI: e141f1d8 EDI: e140fc31 EBP: dec58ef0 ESP: dec58ed0 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Process rmmod (pid: 2530, ti=dec58000 task=decb1940 task.ti=dec58000) Stack: c14293e0 00000282 df624240 c0897d08 c09e86bc c09e86bc e141f1d8 dec58f1c <0> dec58f00 e140fc31 c09e84c4 e141f1bc dec58f14 c0689d21 dec58f1c e141f1bc <0> 00000000 dec58f2c c0689eff c09e84d8 c09e84d8 e141f1bc bff33a90 dec58f38 Call Trace: [<e140fc31>] ? ipv6_frags_exit_net+0x22/0x32 [ipv6] [<c0689d21>] ? ops_exit_list+0x19/0x3d [<c0689eff>] ? unregister_pernet_operations+0x2a/0x51 [<c0689f70>] ? unregister_pernet_subsys+0x17/0x24 [<e140fbfe>] ? ipv6_frag_exit+0x21/0x32 [ipv6] [<e141a361>] ? inet6_exit+0x47/0x122 [ipv6] [<c045f5de>] ? sys_delete_module+0x198/0x1f6 [<c04a8acf>] ? remove_vma+0x57/0x5d [<c070f63f>] ? do_page_fault+0x2e7/0x315 [<c0403218>] ? sysenter_do_call+0x12/0x28 Code: 86 00 00 00 40 c1 e8 0c c1 e0 05 01 d0 89 45 e0 66 83 38 00 79 06 8b 40 0c 89 45 e0 8b 55 e0 8b 02 84 c0 78 14 66 a9 00 c0 75 04 <0f> 0b eb fe 8b 45 e0 e8 35 15 fe ff eb 5d 8b 45 04 8b 55 e0 89 EIP: [<c04b73f2>] kfree+0x6a/0xdd SS:ESP 0068:dec58ed0 ---[ end trace 4475d1a5b0afa7e5 ]--- It's because in ip6_frags_ns_sysctl_register, "table" only alloced when "net" is not equals to "init_net".So when we free "table" in ip6_frags_ns_sysctl_unregister,we should check this first. This patch fix the problem. Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-19 12:25:13 +08:00
if (!net_eq(net, &init_net))
kfree(table);
}
static struct ctl_table_header *ip6_ctl_header;
static int ip6_frags_sysctl_register(void)
{
ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6",
ip6_frags_ctl_table);
return ip6_ctl_header == NULL ? -ENOMEM : 0;
}
static void ip6_frags_sysctl_unregister(void)
{
unregister_net_sysctl_table(ip6_ctl_header);
}
#else
static int ip6_frags_ns_sysctl_register(struct net *net)
{
return 0;
}
static void ip6_frags_ns_sysctl_unregister(struct net *net)
{
}
static int ip6_frags_sysctl_register(void)
{
return 0;
}
static void ip6_frags_sysctl_unregister(void)
{
}
#endif
static int __net_init ipv6_frags_init_net(struct net *net)
{
int res;
net->ipv6.fqdir.high_thresh = IPV6_FRAG_HIGH_THRESH;
net->ipv6.fqdir.low_thresh = IPV6_FRAG_LOW_THRESH;
net->ipv6.fqdir.timeout = IPV6_FRAG_TIMEOUT;
res = fqdir_init(&net->ipv6.fqdir, &ip6_frags);
if (res < 0)
return res;
res = ip6_frags_ns_sysctl_register(net);
if (res < 0)
fqdir_exit(&net->ipv6.fqdir);
return res;
}
static void __net_exit ipv6_frags_exit_net(struct net *net)
{
ip6_frags_ns_sysctl_unregister(net);
fqdir_exit(&net->ipv6.fqdir);
}
static struct pernet_operations ip6_frags_ops = {
.init = ipv6_frags_init_net,
.exit = ipv6_frags_exit_net,
};
static const struct rhashtable_params ip6_rhash_params = {
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
.head_offset = offsetof(struct inet_frag_queue, node),
.hashfn = ip6frag_key_hashfn,
.obj_hashfn = ip6frag_obj_hashfn,
.obj_cmpfn = ip6frag_obj_cmpfn,
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
.automatic_shrinking = true,
};
int __init ipv6_frag_init(void)
{
int ret;
ip6_frags.constructor = ip6frag_init;
ip6_frags.destructor = NULL;
ip6_frags.qsize = sizeof(struct frag_queue);
ip6_frags.frag_expire = ip6_frag_expire;
ip6_frags.frags_cache_name = ip6_frag_cache_name;
inet: frags: use rhashtables for reassembly units Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-01 03:58:49 +08:00
ip6_frags.rhash_params = ip6_rhash_params;
ret = inet_frags_init(&ip6_frags);
if (ret)
goto out;
ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
if (ret)
goto err_protocol;
ret = ip6_frags_sysctl_register();
if (ret)
goto err_sysctl;
ret = register_pernet_subsys(&ip6_frags_ops);
if (ret)
goto err_pernet;
out:
return ret;
err_pernet:
ip6_frags_sysctl_unregister();
err_sysctl:
inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
err_protocol:
inet_frags_fini(&ip6_frags);
goto out;
}
void ipv6_frag_exit(void)
{
inet_frags_fini(&ip6_frags);
ip6_frags_sysctl_unregister();
unregister_pernet_subsys(&ip6_frags_ops);
inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
}