- 20 Oct, 2018 9 commits
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Marek Lindner authored
[ Upstream commit 4c4af690 ] The hardif_neigh refcounter is to be decreased by the queued work and currently is never decreased if the queue_work() call fails. Fix by checking the queue_work() return value and decrease refcount if necessary. Signed-off-by:
Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by:
Sven Eckelmann <sven@narfation.org> Signed-off-by:
Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by:
Sasha Levin <alexander.levin@microsoft.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Marek Lindner authored
[ Upstream commit 5af96b9c ] The backbone_gw refcounter is to be decreased by the queued work and currently is never decreased if the queue_work() call fails. Fix by checking the queue_work() return value and decrease refcount if necessary. Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit ae3cdc97 ] The function batadv_tvlv_handler_register is responsible for adding new tvlv_handler to the handler_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: ef261577 ("batman-adv: tvlv - basic infrastructure") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit e7136e48 ] The function batadv_tt_global_orig_entry_add is responsible for adding new tt_orig_list_entry to the orig_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: d657e621 ("batman-adv: add reference counting for type batadv_tt_orig_list_entry") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit 94cb82f5 ] The function batadv_softif_vlan_get is responsible for adding new softif_vlan to the softif_vlan_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: 5d2c05b2 ("batman-adv: add per VLAN interface attribute framework") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit fa122fec ] The function batadv_nc_get_nc_node is responsible for adding new nc_nodes to the in_coding_list and out_coding_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: d56b1705 ("batman-adv: network coding - detect coding nodes and remove these after timeout") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit a25bab9d ] The per hardif sysfs file "batman_adv/elp_interval" is using the generic functions to store/show uint values. The helper __batadv_store_uint_attr requires the softif net_device as parameter to print the resulting change as info text when the users writes to this file. It uses the helper function batadv_info to add it at the same time to the kernel ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled). The function batadv_info requires as first parameter the batman-adv softif net_device. This parameter is then used to find the private buffer which contains the debug log for this batman-adv interface. But batadv_store_throughput_override used as first argument the slave net_device. This slave device doesn't have the batadv_priv private data which is access by batadv_info. Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead to a segfault or to memory corruption. Fixes: 0744ff8f ("batman-adv: Add hard_iface specific sysfs wrapper macros for UINT") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit b9fd14c2 ] The per hardif sysfs file "batman_adv/throughput_override" prints the resulting change as info text when the users writes to this file. It uses the helper function batadv_info to add it at the same time to the kernel ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled). The function batadv_info requires as first parameter the batman-adv softif net_device. This parameter is then used to find the private buffer which contains the debug log for this batman-adv interface. But batadv_store_throughput_override used as first argument the slave net_device. This slave device doesn't have the batadv_priv private data which is access by batadv_info. Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead to a segfault or to memory corruption. Fixes: 0b5ecc68 ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by:
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Jozef Balga authored
[ Upstream commit 312f73b6 ] When less than 3 bytes are written to the device, memcpy is called with negative array size which leads to buffer overflow and kernel panic. This patch adds a condition and returns -EOPNOTSUPP instead. Fixes bugzilla issue 64871 [mchehab+samsung@kernel.org: fix a merge conflict and changed the condition to match the patch's comment, e. g. len == 3 could also be valid] Signed-off-by:
Jozef Balga <jozef.balga@gmail.com> Signed-off-by:
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by:
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- 18 Oct, 2018 31 commits
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Greg Kroah-Hartman authored
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Dan Carpenter authored
(commit 70837ffe upstream) We accidentally removed the parentheses here, but they are required because '!' has higher precedence than '&'. Fixes: fa0f5273 ("ip: use rb trees for IP frag queue.") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Taehee Yoo authored
commit 5d407b07 upstream A kernel crash occurrs when defragmented packet is fragmented in ip_do_fragment(). In defragment routine, skb_orphan() is called and skb->ip_defrag_offset is set. but skb->sk and skb->ip_defrag_offset are same union member. so that frag->sk is not NULL. Hence crash occurrs in skb->sk check routine in ip_do_fragment() when defragmented packet is fragmented. test commands: %iptables -t nat -I POSTROUTING -j MASQUERADE %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000 splat looks like: [ 261.069429] kernel BUG at net/ipv4/ip_output.c:636! [ 261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3 [ 261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600 [ 261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c [ 261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202 [ 261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004 [ 261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8 [ 261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395 [ 261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4 [ 261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000 [ 261.174169] FS: 00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000 [ 261.183012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0 [ 261.198158] Call Trace: [ 261.199018] ? dst_output+0x180/0x180 [ 261.205011] ? save_trace+0x300/0x300 [ 261.209018] ? ip_copy_metadata+0xb00/0xb00 [ 261.213034] ? sched_clock_local+0xd4/0x140 [ 261.218158] ? kill_l4proto+0x120/0x120 [nf_conntrack] [ 261.223014] ? rt_cpu_seq_stop+0x10/0x10 [ 261.227014] ? find_held_lock+0x39/0x1c0 [ 261.233008] ip_finish_output+0x51d/0xb50 [ 261.237006] ? ip_fragment.constprop.56+0x220/0x220 [ 261.243011] ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack] [ 261.250152] ? rcu_is_watching+0x77/0x120 [ 261.255010] ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4] [ 261.261033] ? nf_hook_slow+0xb1/0x160 [ 261.265007] ip_output+0x1c7/0x710 [ 261.269005] ? ip_mc_output+0x13f0/0x13f0 [ 261.273002] ? __local_bh_enable_ip+0xe9/0x1b0 [ 261.278152] ? ip_fragment.constprop.56+0x220/0x220 [ 261.282996] ? nf_hook_slow+0xb1/0x160 [ 261.287007] raw_sendmsg+0x21f9/0x4420 [ 261.291008] ? dst_output+0x180/0x180 [ 261.297003] ? sched_clock_cpu+0x126/0x170 [ 261.301003] ? find_held_lock+0x39/0x1c0 [ 261.306155] ? stop_critical_timings+0x420/0x420 [ 261.311004] ? check_flags.part.36+0x450/0x450 [ 261.315005] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.320995] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.326142] ? cyc2ns_read_end+0x10/0x10 [ 261.330139] ? raw_bind+0x280/0x280 [ 261.334138] ? sched_clock_cpu+0x126/0x170 [ 261.338995] ? check_flags.part.36+0x450/0x450 [ 261.342991] ? __lock_acquire+0x4500/0x4500 [ 261.348994] ? inet_sendmsg+0x11c/0x500 [ 261.352989] ? dst_output+0x180/0x180 [ 261.357012] inet_sendmsg+0x11c/0x500 [ ... ] v2: - clear skb->sk at reassembly routine.(Eric Dumarzet) Fixes: fa0f5273 ("ip: use rb trees for IP frag queue.") Suggested-by:
Eric Dumazet <edumazet@google.com> Signed-off-by:
Taehee Yoo <ap420073@gmail.com> Reviewed-by:
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Peter Oskolkov authored
This patch changes the runtime behavior of IP defrag queue: incoming in-order fragments are added to the end of the current list/"run" of in-order fragments at the tail. On some workloads, UDP stream performance is substantially improved: RX: ./udp_stream -F 10 -T 2 -l 60 TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60 with this patchset applied on a 10Gbps receiver: throughput=9524.18 throughput_units=Mbit/s upstream (net-next): throughput=4608.93 throughput_units=Mbit/s Reported-by:
Willem de Bruijn <willemb@google.com> Signed-off-by:
Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by:
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Peter Oskolkov authored
This patch introduces several helper functions/macros that will be used in the follow-up patch. No runtime changes yet. The new logic (fully implemented in the second patch) is as follows: * Nodes in the rb-tree will now contain not single fragments, but lists of consecutive fragments ("runs"). * At each point in time, the current "active" run at the tail is maintained/tracked. Fragments that arrive in-order, adjacent to the previous tail fragment, are added to this tail run without triggering the re-balancing of the rb-tree. * If a fragment arrives out of order with the offset _before_ the tail run, it is inserted into the rb-tree as a single fragment. * If a fragment arrives after the current tail fragment (with a gap), it starts a new "tail" run, as is inserted into the rb-tree at the end as the head of the new run. skb->cb is used to store additional information needed here (suggested by Eric Dumazet). Reported-by: -
Peter Oskolkov authored
(commit fa0f5273 upstream) Similar to TCP OOO RX queue, it makes sense to use rb trees to store IP fragments, so that OOO fragments are inserted faster. Tested: - a follow-up patch contains a rather comprehensive ip defrag self-test (functional) - ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`: netstat --statistics Ip: 282078937 total packets received 0 forwarded 0 incoming packets discarded 946760 incoming packets delivered 18743456 requests sent out 101 fragments dropped after timeout 282077129 reassemblies required 944952 packets reassembled ok 262734239 packet reassembles failed (The numbers/stats above are somewhat better re: reassemblies vs a kernel without this patchset. More comprehensive performance testing TBD). Reported-by:
Jann Horn <jannh@google.com> Reported-by:
Juha-Matti Tilli <juha-matti.tilli@iki.fi> Suggested-by:
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Eric Dumazet authored
Geeralize private netem_rb_to_skb() TCP rtx queue will soon be converted to rb-tree, so we will need skb_rbtree_walk() helpers. Signed-off-by:
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Eric Dumazet authored
After working on IP defragmentation lately, I found that some large packets defeat CHECKSUM_COMPLETE optimization because of NIC adding zero paddings on the last (small) fragment. While removing the padding with pskb_trim_rcsum(), we set skb->ip_summed to CHECKSUM_NONE, forcing a full csum validation, even if all prior fragments had CHECKSUM_COMPLETE set. We can instead compute the checksum of the part we are trimming, usually smaller than the part we keep. Signed-off-by:
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Florian Westphal authored
don't bother with pathological cases, they only waste cycles. IPv6 requires a minimum MTU of 1280 so we should never see fragments smaller than this (except last frag). v3: don't use awkward "-offset + len" v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68). There were concerns that there could be even smaller frags generated by intermediate nodes, e.g. on radio networks. Cc: Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by:Florian Westphal <fw@strlen.de> Signed-off-by:
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Peter Oskolkov authored
Tested: see the next patch is the series. Suggested-by:
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Eric Dumazet authored
As measured in my prior patch ("sch_netem: faster rb tree removal"), rbtree_postorder_for_each_entry_safe() is nice looking but much slower than using rb_next() directly, except when tree is small enough to fit in CPU caches (then the cost is the same) Also note that there is not even an increase of text size : $ size net/core/skbuff.o.before net/core/skbuff.o text data bss dec hex filename 40711 1298 0 42009 a419 net/core/skbuff.o.before 40711 1298 0 42009 a419 net/core/skbuff.o From: Eric Dumazet <edumazet@google.com> Signed-off-by: -
Peter Oskolkov authored
This behavior is required in IPv6, and there is little need to tolerate overlapping fragments in IPv4. This change simplifies the code and eliminates potential DDoS attack vectors. Tested: ran ip_defrag selftest (not yet available uptream). Suggested-by:
Stephen Hemminger <stephen@networkplumber.org> Signed-off-by:
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Eric Dumazet authored
Giving an integer to proc_doulongvec_minmax() is dangerous on 64bit arches, since linker might place next to it a non zero value preventing a change to ip6frag_low_thresh. ip6frag_low_thresh is not used anymore in the kernel, but we do not want to prematuraly break user scripts wanting to change it. Since specifying a minimal value of 0 for proc_doulongvec_minmax() is moot, let's remove these zero values in all defrag units. Fixes: 6e00f7dd ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh") Signed-off-by:
Maciej Żenczykowski <maze@google.com> Signed-off-by:
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Eric Dumazet authored
ip_defrag uses skb->cb[] to store the fragment offset, and unfortunately this integer is currently in a different cache line than skb->next, meaning that we use two cache lines per skb when finding the insertion point. By aliasing skb->ip_defrag_offset and skb->dev, we pack all the fields in a single cache line and save precious memory bandwidth. Note that after the fast path added by Changli Gao in commit d6bebca9 ("fragment: add fast path for in-order fragments") this change wont help the fast path, since we still need to access prev->len (2nd cache line), but will show great benefits when slow path is entered, since we perform a linear scan of a potentially long list. Also, note that this potential long list is an attack vector, we might consider also using an rb-tree there eventually. Signed-off-by:
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Eric Dumazet authored
Put the read-mostly fields in a separate cache line at the beginning of struct netns_frags, to reduce false sharing noticed in inet_frag_kill() Signed-off-by:
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Eric Dumazet authored
While under frags DDOS I noticed unfortunate false sharing between @nelems and @params.automatic_shrinking Move @nelems at the end of struct rhashtable so that first cache line is shared between all cpus, because almost never dirtied. Signed-off-by:
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Eric Dumazet authored
Make it similar to IPv4 ip_expire(), and release the lock before calling icmp functions. Signed-off-by:
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Eric Dumazet authored
An skb_clone() was added in commit ec4fbd64 ("inet: frag: release spinlock before calling icmp_send()") While fixing the bug at that time, it also added a very high cost for DDOS frags, as the ICMP rate limit is applied after this expensive operation (skb_clone() + consume_skb(), implying memory allocations, copy, and freeing) We can use skb_get(head) here, all we want is to make sure skb wont be freed by another cpu. Signed-off-by:
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Eric Dumazet authored
Some users are willing to provision huge amounts of memory to be able to perform reassembly reasonnably well under pressure. Current memory tracking is using one atomic_t and integers. Switch to atomic_long_t so that 64bit arches can use more than 2GB, without any cost for 32bit arches. Note that this patch avoids an overflow error, if high_thresh was set to ~2GB, since this test in inet_frag_alloc() was never true : if (... || frag_mem_limit(nf) > nf->high_thresh) Tested: $ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh <frag DDOS> $ grep FRAG /proc/net/sockstat FRAG: inuse 14705885 memory 16000002880 $ nstat -n ; sleep 1 ; nstat | grep Reas IpReasmReqds 3317150 0.0 IpReasmFails 3317112 0.0 Signed-off-by:
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Eric Dumazet authored
This function is obsolete, after rhashtable addition to inet defrag. Signed-off-by:
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Eric Dumazet authored
This refactors ip_expire() since one indentation level is removed. Note: in the future, we should try hard to avoid the skb_clone() since this is a serious performance cost. Under DDOS, the ICMP message wont be sent because of rate limits. Fact that ip6_expire_frag_queue() does not use skb_clone() is disturbing too. Presumably IPv6 should have the same issue than the one we fixed in commit ec4fbd64 ("inet: frag: release spinlock before calling icmp_send()") Signed-off-by:
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Eric Dumazet authored
Remove sum_frag_mem_limit(), ip_frag_mem() & ip6_frag_mem() Also since we use rhashtable we can bring back the number of fragments in "grep FRAG /proc/net/sockstat /proc/net/sockstat6" that was removed in commit 434d3054 ("inet: frag: don't account number of fragment queues") Signed-off-by:
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Eric Dumazet authored
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:
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Eric Dumazet authored
Rehashing and destroying large hash table takes a lot of time, and happens in process context. It is safe to add cond_resched() in rhashtable_rehash_table() and rhashtable_free_and_destroy() Signed-off-by:
Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
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Eric Dumazet authored
IPv4 was changed in commit 52a773d6 ("net: Export ip fragment sysctl to unprivileged users") The only sysctl that is not per-netns is not used : ip6frag_secret_interval Signed-off-by:
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Eric Dumazet authored
We want to call lowpan_net_frag_init() earlier. Similar to commit "inet: frags: refactor ipv6_frag_init()" This is a prereq to "inet: frags: use rhashtables for reassembly units" Signed-off-by:
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Eric Dumazet authored
We want to call inet_frags_init() earlier. This is a prereq to "inet: frags: use rhashtables for reassembly units" Signed-off-by:
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Eric Dumazet authored
We need to call inet_frags_init() before register_pernet_subsys(), as a prereq for following patch ("inet: frags: use rhashtables for reassembly units") Signed-off-by: -
Eric Dumazet authored
In order to simplify the API, add a pointer to struct inet_frags. This will allow us to make things less complex. These functions no longer have a struct inet_frags parameter : inet_frag_destroy(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_put(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_kill(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frags_exit_net(struct netns_frags *nf /*, struct inet_frags *f */) ip6_expire_frag_queue(struct net *net, struct frag_queue *fq) Signed-off-by:
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Eric Dumazet authored
We will soon initialize one rhashtable per struct netns_frags in inet_frags_init_net(). This patch changes the return value to eventually propagate an error. Signed-off-by:
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Eric Dumazet authored
[ Upstream commit 2ab2ddd3 ] Timer handlers do not imply rcu_read_lock(), so my recent fix triggered a LOCKDEP warning when SYNACK is retransmit. Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt usages instead of guessing what is done by callers, since it is not worth the pain. Get rid of ireq_opt_deref() helper since it hides the logic without real benefit, since it is now a standard rcu_dereference(). Fixes: 1ad98e9d ("tcp/dccp: fix lockdep issue when SYN is backlogged") Signed-off-by:
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