linux-toradex.git/net/ipv6, branch v3.0.3

ipv6: make fragment identifications less predictable

2011-08-16T01:31:37+00:00

[ Backport of upstream commit 87c48fa3b4630905f98268dde838ee43626a060c ]

Fernando Gont reported current IPv6 fragment identification generation
was not secure, because using a very predictable system-wide generator,
allowing various attacks.

IPv4 uses inetpeer cache to address this problem and to get good
performance. We'll use this mechanism when IPv6 inetpeer is stable
enough in linux-3.1

For the time being, we use jhash on destination address to provide less
predictable identifications. Also remove a spinlock and use cmpxchg() to
get better SMP performance.

Reported-by: Fernando Gont 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Compute protocol sequence numbers and fragment IDs using MD5.

2011-08-16T01:31:35+00:00

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.

Reported-by: Dan Kaminsky 
Tested-by: Willy Tarreau 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: bind() fix error return on wrong address family

2011-07-05T04:37:41+00:00

Hi,

Reinhard Max also pointed out that the error should EAFNOSUPPORT according
to POSIX.

The Linux manpages have it as EINVAL, some other OSes (Minix, HPUX, perhaps BSD) use
EAFNOSUPPORT. Windows uses WSAEFAULT according to MSDN.

Other protocols error values in their af bind() methods in current mainline git as far
as a brief look shows:
	EAFNOSUPPORT: atm, appletalk, l2tp, llc, phonet, rxrpc
	EINVAL: ax25, bluetooth, decnet, econet, ieee802154, iucv, netlink, netrom, packet, rds, rose, unix, x25,
	No check?: can/raw, ipv6/raw, irda, l2tp/l2tp_ip

Ciao, Marcus

Signed-off-by: Marcus Meissner 
Cc: Reinhard Max 
Signed-off-by: David S. Miller

ipv6: Don't put artificial limit on routing table size.

2011-07-02T00:30:43+00:00

IPV6, unlike IPV4, doesn't have a routing cache.

Routing table entries, as well as clones made in response
to route lookup requests, all live in the same table.  And
all of these things are together collected in the destination
cache table for ipv6.

This means that routing table entries count against the garbage
collection limits, even though such entries cannot ever be reclaimed
and are added explicitly by the administrator (rather than being
created in response to lookups).

Therefore it makes no sense to count ipv6 routing table entries
against the GC limits.

Add a DST_NOCOUNT destination cache entry flag, and skip the counting
if it is set.  Use this flag bit in ipv6 when adding routing table
entries.

Signed-off-by: David S. Miller

ipv6: Don't change dst->flags using assignments.

2011-07-02T00:30:43+00:00

This blows away any flags already set in the entry.

Signed-off-by: David S. Miller

udp/recvmsg: Clear MSG_TRUNC flag when starting over for a new packet

2011-06-22T05:34:27+00:00

Consider this scenario: When the size of the first received udp packet
is bigger than the receive buffer, MSG_TRUNC bit is set in msg->msg_flags.
However, if checksum error happens and this is a blocking socket, it will
goto try_again loop to receive the next packet.  But if the size of the
next udp packet is smaller than receive buffer, MSG_TRUNC flag should not
be set, but because MSG_TRUNC bit is not cleared in msg->msg_flags before
receive the next packet, MSG_TRUNC is still set, which is wrong.

Fix this problem by clearing MSG_TRUNC flag when starting over for a
new packet.

Signed-off-by: Xufeng Zhang 
Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller

ipv6/udp: Use the correct variable to determine non-blocking condition

2011-06-22T05:34:27+00:00

udpv6_recvmsg() function is not using the correct variable to determine
whether or not the socket is in non-blocking operation, this will lead
to unexpected behavior when a UDP checksum error occurs.

Consider a non-blocking udp receive scenario: when udpv6_recvmsg() is
called by sock_common_recvmsg(), MSG_DONTWAIT bit of flags variable in
udpv6_recvmsg() is cleared by "flags & ~MSG_DONTWAIT" in this call:

    err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
                   flags & ~MSG_DONTWAIT, &addr_len);

i.e. with udpv6_recvmsg() getting these values:

	int noblock = flags & MSG_DONTWAIT
	int flags = flags & ~MSG_DONTWAIT

So, when udp checksum error occurs, the execution will go to
csum_copy_err, and then the problem happens:

    csum_copy_err:
            ...............
            if (flags & MSG_DONTWAIT)
                    return -EAGAIN;
            goto try_again;
            ...............

But it will always go to try_again as MSG_DONTWAIT has been cleared
from flags at call time -- only noblock contains the original value
of MSG_DONTWAIT, so the test should be:

            if (noblock)
                    return -EAGAIN;

This is also consistent with what the ipv4/udp code does.

Signed-off-by: Xufeng Zhang 
Signed-off-by: Paul Gortmaker 
Signed-off-by: David S. Miller

net: rfs: enable RFS before first data packet is received

2011-06-17T19:27:31+00:00

Le jeudi 16 juin 2011 à 23:38 -0400, David Miller a écrit :
> From: Ben Hutchings 
> Date: Fri, 17 Jun 2011 00:50:46 +0100
>
> > On Wed, 2011-06-15 at 04:15 +0200, Eric Dumazet wrote:
> >> @@ -1594,6 +1594,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
> >>  			goto discard;
> >>
> >>  		if (nsk != sk) {
> >> +			sock_rps_save_rxhash(nsk, skb->rxhash);
> >>  			if (tcp_child_process(sk, nsk, skb)) {
> >>  				rsk = nsk;
> >>  				goto reset;
> >>
> >
> > I haven't tried this, but it looks reasonable to me.
> >
> > What about IPv6?  The logic in tcp_v6_do_rcv() looks very similar.
>
> Indeed ipv6 side needs the same fix.
>
> Eric please add that part and resubmit.  And in fact I might stick
> this into net-2.6 instead of net-next-2.6
>

OK, here is the net-2.6 based one then, thanks !

[PATCH v2] net: rfs: enable RFS before first data packet is received

First packet received on a passive tcp flow is not correctly RFS
steered.

One sock_rps_record_flow() call is missing in inet_accept()

But before that, we also must record rxhash when child socket is setup.

Signed-off-by: Eric Dumazet 
CC: Tom Herbert 
CC: Ben Hutchings 
CC: Jamal Hadi Salim 
Signed-off-by: David S. Miller

netfilter: fix looped (broad|multi)cast's MAC handling

2011-06-16T15:27:04+00:00

By default, when broadcast or multicast packet are sent from a local
application, they are sent to the interface then looped by the kernel
to other local applications, going throught netfilter hooks in the
process.

These looped packet have their MAC header removed from the skb by the
kernel looping code. This confuse various netfilter's netlink queue,
netlink log and the legacy ip_queue, because they try to extract a
hardware address from these packets, but extracts a part of the IP
header instead.

This patch prevent NFQUEUE, NFLOG and ip_QUEUE to include a MAC header
if there is none in the packet.

Signed-off-by: Nicolas Cavallari 
Signed-off-by: Patrick McHardy

net/ipv6: check for mistakenly passed in non-AF_INET6 sockaddrs

2011-06-06T21:48:16+00:00

Same check as for IPv4, also do for IPv6.

(If you passed in a IPv4 sockaddr_in here, the sizeof check
 in the line before would have triggered already though.)

Signed-off-by: Marcus Meissner 
Cc: Reinhard Max 
Signed-off-by: David S. Miller