Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 14 6月, 2008 1 次提交
  3. 13 6月, 2008 2 次提交
    • D
      tcp: Revert 'process defer accept as established' changes. · ec0a1966
      由 David S. Miller 提交于 
      This reverts two changesets, ec3c0982
("[TCP]: TCP_DEFER_ACCEPT updates - process as established") and
the follow-on bug fix 9ae27e0a
("tcp: Fix slab corruption with ipv6 and tcp6fuzz").

This change causes several problems, first reported by Ingo Molnar
as a distcc-over-loopback regression where connections were getting
stuck.

Ilpo Järvinen first spotted the locking problems.  The new function
added by this code, tcp_defer_accept_check(), only has the
child socket locked, yet it is modifying state of the parent
listening socket.

Fixing that is non-trivial at best, because we can't simply just grab
the parent listening socket lock at this point, because it would
create an ABBA deadlock.  The normal ordering is parent listening
socket --> child socket, but this code path would require the
reverse lock ordering.

Next is a problem noticed by Vitaliy Gusev, he noted:

----------------------------------------
>--- a/net/ipv4/tcp_timer.c
>+++ b/net/ipv4/tcp_timer.c
>@@ -481,6 +481,11 @@ static void tcp_keepalive_timer (unsigned long data)
> 		goto death;
> 	}
>
>+	if (tp->defer_tcp_accept.request && sk->sk_state == TCP_ESTABLISHED) {
>+		tcp_send_active_reset(sk, GFP_ATOMIC);
>+		goto death;

Here socket sk is not attached to listening socket's request queue. tcp_done()
will not call inet_csk_destroy_sock() (and tcp_v4_destroy_sock() which should
release this sk) as socket is not DEAD. Therefore socket sk will be lost for
freeing.
----------------------------------------

Finally, Alexey Kuznetsov argues that there might not even be any
real value or advantage to these new semantics even if we fix all
of the bugs:

----------------------------------------
Hiding from accept() sockets with only out-of-order data only
is the only thing which is impossible with old approach. Is this really
so valuable? My opinion: no, this is nothing but a new loophole
to consume memory without control.
----------------------------------------

So revert this thing for now.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ec0a1966
    • D
      ipv6: Fix duplicate initialization of rawv6_prot.destroy · f23d60de
      由 David S. Miller 提交于 
      In changeset 22dd4850
("raw: Raw socket leak.") code was added so that we
flush pending frames on raw sockets to avoid leaks.

The ipv4 part was fine, but the ipv6 part was not
done correctly.  Unlike the ipv4 side, the ipv6 code
already has a .destroy method for rawv6_prot.

So now there were two assignments to this member, and
what the compiler does is use the last one, effectively
making the ipv6 parts of that changeset a NOP.

Fix this by removing the:

	.destroy	   = inet6_destroy_sock,

line, and adding an inet6_destroy_sock() call to the
end of raw6_destroy().

Noticed by Al Viro.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
      f23d60de
  5. 12 6月, 2008 7 次提交
  7. 11 6月, 2008 9 次提交
    • G
      dccp: Bug in initial acknowledgment number assignment · be4c798a
      由 Gerrit Renker 提交于 
      Step 8.5 in RFC 4340 says for the newly cloned socket

           Initialize S.GAR := S.ISS,

but what in fact the code (minisocks.c) does is

           Initialize S.GAR := S.ISR,

which is wrong (typo?) -- fixed by the patch.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      be4c798a
    • G
      dccp ccid-3: X truncated due to type conversion · 7deb0f85
      由 Gerrit Renker 提交于 
      This fixes a bug in computing the inter-packet-interval t_ipi = s/X: 

 scaled_div32(a, b) uses u32 for b, but in "scaled_div32(s, X)" the type of the
 sending rate `X' is u64. Since X is scaled by 2^6, this truncates rates greater
 than 2^26 Bps (~537 Mbps).

Using full 64-bit division now.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      7deb0f85
    • G
      dccp ccid-3: TFRC reverse-lookup Bug-Fix · 1e8a287c
      由 Gerrit Renker 提交于 
      This fixes a bug in the reverse lookup of p: given a value f(p), instead of p,
the function returned the smallest tabulated value f(p).

The smallest tabulated value of
	 
   10^6 * f(p) =  sqrt(2*p/3) + 12 * sqrt(3*p/8) * (32 * p^3 + p) 

for p=0.0001 is 8172. 

Since this value is scaled by 10^6, the outcome of this bug is that a loss
of 8172/10^6 = 0.8172% was reported whenever the input was below the table
resolution of 0.01%.

This means that the value was over 80 times too high, resulting in large spikes
of the initial loss interval, thus unnecessarily reducing the throughput.

Also corrected the printk format (%u for u32).
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      1e8a287c
    • G
      dccp ccid-2: Bug-Fix - Ack Vectors need to be ignored on request sockets · 65907a43
      由 Gerrit Renker 提交于 
      This fixes an oversight from an earlier patch, ensuring that Ack Vectors
are not processed on request sockets.

The issue is that Ack Vectors must not be parsed on request sockets, since
the Ack Vector feature depends on the selection of the (TX) CCID. During the
initial handshake the CCIDs are undefined, and so RFC 4340, 10.3 applies:

 "Using CCID-specific options and feature options during a negotiation
  for the corresponding CCID feature is NOT RECOMMENDED [...]"

And it is not even possible: when the server receives the Request from the 
client, the CCID and Ack vector features are undefined; when the Ack finalising
the 3-way hanshake arrives, the request socket has not been cloned yet into a
full socket. (This order is necessary, since otherwise the newly created socket
would have to be destroyed whenever an option error occurred - a malicious
hacker could simply send garbage options and exploit this.)
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      65907a43
    • G
      dccp: Fix sparse warnings · 1e2f0e5e
      由 Gerrit Renker 提交于 
      This patch fixes the following sparse warnings:
 * nested min(max()) expression:
   net/dccp/ccids/ccid3.c:91:21: warning: symbol '__x' shadows an earlier one
   net/dccp/ccids/ccid3.c:91:21: warning: symbol '__y' shadows an earlier one
   
 * Declaration of function prototypes in .c instead of .h file, resulting in
   "should it be static?" warnings. 

 * Declared "struct dccpw" static (local to dccp_probe).
 
 * Disabled dccp_delayed_ack() - not fully removed due to RFC 4340, 11.3
   ("Receivers SHOULD implement delayed acknowledgement timers ...").

 * Used a different local variable name to avoid
   net/dccp/ackvec.c:293:13: warning: symbol 'state' shadows an earlier one
   net/dccp/ackvec.c:238:33: originally declared here

 * Removed unused functions `dccp_ackvector_print' and `dccp_ackvec_print'.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      1e2f0e5e
    • G
      dccp ccid-3: Bug-Fix - Zero RTT is possible · 3294f202
      由 Gerrit Renker 提交于 
      In commit $(825de27d) (from 27th May, commit
message `dccp ccid-3: Fix "t_ipi explosion" bug'), the CCID-3 window counter
computation was fixed to cope with RTTs < 4 microseconds.

Such RTTs can be found e.g. when running CCID-3 over loopback. The fix removed
a check against RTT < 4, but introduced a divide-by-zero bug.

All steady-state RTTs in DCCP are filtered using dccp_sample_rtt(), which
ensures non-zero samples. However, a zero RTT is possible on initialisation,
when there is no RTT sample from the Request/Response exchange.

The fix is to use the fallback-RTT from RFC 4340, 3.4.

This is also better than just fixing update_win_count() since it allows other
parts of the code to always assume that the RTT is non-zero during the time
that the CCID is used.
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
      3294f202
    • K
      net: Fix routing tables with id > 255 for legacy software · 709772e6
      由 Krzysztof Piotr Oledzki 提交于 
      Most legacy software do not like tables > 255 as rtm_table is u8
so tb_id is sent &0xff and it is possible to mismatch for example
table 510 with table 254 (main).

This patch introduces RT_TABLE_COMPAT=252 so the code uses it if
tb_id > 255. It makes such old applications happy, new
ones are still able to use RTA_TABLE to get a proper table id.
Signed-off-by: NKrzysztof Piotr Oledzki <ole@ans.pl>
Acked-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      709772e6
    • J
      ipsec: pfkey should ignore events when no listeners · 99c6f60e
      由 Jamal Hadi Salim 提交于 
      When pfkey has no km listeners, it still does a lot of work
before finding out there aint nobody out there.
If a tree falls in a forest and no one is around to hear it, does it make
a sound? In this case it makes a lot of noise:
With this short-circuit adding 10s of thousands of SAs using
netlink improves performance by ~10%.
Signed-off-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      99c6f60e
    • A
      inet{6}_request_sock: Init ->opt and ->pktopts in the constructor · ce4a7d0d
      由 Arnaldo Carvalho de Melo 提交于 
      Wei Yongjun noticed that we may call reqsk_free on request sock objects where
the opt fields may not be initialized, fix it by introducing inet_reqsk_alloc
where we initialize ->opt to NULL and set ->pktopts to NULL in
inet6_reqsk_alloc.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ce4a7d0d
  9. 10 6月, 2008 5 次提交
  11. 05 6月, 2008 16 次提交