linux-toradex.git/net/ipv6/mcast.c, branch v4.10

igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()

2017-02-09T21:43:45+00:00

In function igmpv3/mld_add_delrec() we allocate pmc and put it in
idev->mc_tomb, so we should free it when we don't need it in del_delrec().
But I removed kfree(pmc) incorrectly in latest two patches. Now fix it.

Fixes: 24803f38a5c0 ("igmp: do not remove igmp souce list info when ...")
Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when ...")
Reported-by: Daniel Borkmann 
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller

mld: do not remove mld souce list info when set link down

2017-01-16T17:44:59+00:00

This is an IPv6 version of commit 24803f38a5c0 ("igmp: do not remove igmp
souce list..."). In mld_del_delrec(), we will restore back all source filter
info instead of flush them.

Move mld_clear_delrec() from ipv6_mc_down() to ipv6_mc_destroy_dev() since
we should not remove source list info when set link down. Remove
igmp6_group_dropped() in ipv6_mc_destroy_dev() since we have called it in
ipv6_mc_down().

Also clear all source info after igmp6_group_dropped() instead of in it
because ipv6_mc_down() will call igmp6_group_dropped().

Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller

ipv6: fix a potential deadlock in do_ipv6_setsockopt()

2016-10-21T15:29:02+00:00

Baozeng reported this deadlock case:

       CPU0                    CPU1
       ----                    ----
  lock([  165.136033] sk_lock-AF_INET6);
                               lock([  165.136033] rtnl_mutex);
                               lock([  165.136033] sk_lock-AF_INET6);
  lock([  165.136033] rtnl_mutex);

Similar to commit 87e9f0315952
("ipv4: fix a potential deadlock in mcast getsockopt() path")
this is due to we still have a case, ipv6_sock_mc_close(),
where we acquire sk_lock before rtnl_lock. Close this deadlock
with the similar solution, that is always acquire rtnl lock first.

Fixes: baf606d9c9b1 ("ipv4,ipv6: grab rtnl before locking the socket")
Reported-by: Baozeng Ding 
Tested-by: Baozeng Ding 
Cc: Marcelo Ricardo Leitner 
Signed-off-by: Cong Wang 
Reviewed-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

net/multicast: should not send source list records when have filter mode change

2016-08-08T23:04:39+00:00

Based on RFC3376 5.1 and RFC3810 6.1

   If the per-interface listening change that triggers the new report is
   a filter mode change, then the next [Robustness Variable] State
   Change Reports will include a Filter Mode Change Record.  This
   applies even if any number of source list changes occur in that
   period.

   Old State         New State         State Change Record Sent
   ---------         ---------         ------------------------
   INCLUDE (A)       EXCLUDE (B)       TO_EX (B)
   EXCLUDE (A)       INCLUDE (B)       TO_IN (B)

So we should not send source-list change if there is a filter-mode change.

Here are two scenarios:
1. Group deleted and filter mode is EXCLUDE, which means we need send a
   TO_IN { }.
2. Not group deleted, but has pcm->crcount, which means we need send a
   normal filter-mode-change.

At the same time, if the type is ALLOW or BLOCK, and have psf->sf_crcount,
we stop add records and decrease sf_crcount directly

Reference: https://www.ietf.org/mail-archive/web/magma/current/msg01274.html

Signed-off-by: Hangbin Liu 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

mld, igmp: Fix reserved tailroom calculation

2016-03-03T20:41:07+00:00

The current reserved_tailroom calculation fails to take hlen and tlen into
account.

skb:
[__hlen__|__data____________|__tlen___|__extra__]
^                                               ^
head                                            skb_end_offset

In this representation, hlen + data + tlen is the size passed to alloc_skb.
"extra" is the extra space made available in __alloc_skb because of
rounding up by kmalloc. We can reorder the representation like so:

[__hlen__|__data____________|__extra__|__tlen___]
^                                               ^
head                                            skb_end_offset

The maximum space available for ip headers and payload without
fragmentation is min(mtu, data + extra). Therefore,
reserved_tailroom
= data + extra + tlen - min(mtu, data + extra)
= skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen)
= skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen)

Compare the second line to the current expression:
reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset)
and we can see that hlen and tlen are not taken into account.

The min() in the third line can be expanded into:
if mtu < skb_tailroom - tlen:
	reserved_tailroom = skb_tailroom - mtu
else:
	reserved_tailroom = tlen

Depending on hlen, tlen, mtu and the number of multicast address records,
the current code may output skbs that have less tailroom than
dev->needed_tailroom or it may output more skbs than needed because not all
space available is used.

Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs")
Signed-off-by: Benjamin Poirier 
Acked-by: Hannes Frederic Sowa 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

snmp: Remove duplicate OUTMCAST stat increment

2015-11-16T21:36:32+00:00

the OUTMCAST stat is double incremented, getting bumped once in the mcast code
itself, and again in the common ip output path.  Remove the mcast bump, as its
not needed

Validated by the reporter, with good results

Signed-off-by: Neil Horman 
Reported-by: Claus Jensen 
CC: Claus Jensen 
CC: David Miller 
Signed-off-by: David S. Miller

net: Pass net into dst_output and remove dst_output_okfn

2015-10-08T11:26:54+00:00

Replace dst_output_okfn with dst_output

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

netfilter: Pass net into okfn

2015-09-18T00:18:37+00:00

This is immediately motivated by the bridge code that chains functions that
call into netfilter.  Without passing net into the okfns the bridge code would
need to guess about the best expression for the network namespace to process
packets in.

As net is frequently one of the first things computed in continuation functions
after netfilter has done it's job passing in the desired network namespace is in
many cases a code simplification.

To support this change the function dst_output_okfn is introduced to
simplify passing dst_output as an okfn.  For the moment dst_output_okfn
just silently drops the struct net.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

netfilter: Pass struct net into the netfilter hooks

2015-09-18T00:18:37+00:00

Pass a network namespace parameter into the netfilter hooks.  At the
call site of the netfilter hooks the path a packet is taking through
the network stack is well known which allows the network namespace to
be easily and reliabily.

This allows the replacement of magic code like
"dev_net(state->in?:state->out)" that appears at the start of most
netfilter hooks with "state->net".

In almost all cases the network namespace passed in is derived
from the first network device passed in, guaranteeing those
paths will not see any changes in practice.

The exceptions are:
xfrm/xfrm_output.c:xfrm_output_resume()         xs_net(skb_dst(skb)->xfrm)
ipvs/ip_vs_xmit.c:ip_vs_nat_send_or_cont()      ip_vs_conn_net(cp)
ipvs/ip_vs_xmit.c:ip_vs_send_or_cont()          ip_vs_conn_net(cp)
ipv4/raw.c:raw_send_hdrinc()                    sock_net(sk)
ipv6/ip6_output.c:ip6_xmit()			sock_net(sk)
ipv6/ndisc.c:ndisc_send_skb()                   dev_net(skb->dev) not dev_net(dst->dev)
ipv6/raw.c:raw6_send_hdrinc()                   sock_net(sk)
br_netfilter_hooks.c:br_nf_pre_routing_finish() dev_net(skb->dev) before skb->dev is set to nf_bridge->physindev

In all cases these exceptions seem to be a better expression for the
network namespace the packet is being processed in then the historic
"dev_net(in?in:out)".  I am documenting them in case something odd
pops up and someone starts trying to track down what happened.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

net: Merge dst_output and dst_output_sk

2015-09-18T00:18:32+00:00

Add a sock paramter to dst_output making dst_output_sk superfluous.
Add a skb->sk parameter to all of the callers of dst_output
Have the callers of dst_output_sk call dst_output.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller