net: do not pretend FRAGLIST support
rds: prevent BUG_ON triggered on congestion update to loopback

[ Upstream commit 18fc25c94eadc52a42c025125af24657a93638c0 ]

After congestion update on a local connection, when rds_ib_xmit returns
less bytes than that are there in the message, rds_send_xmit calls
back rds_ib_xmit with an offset that causes BUG_ON(off & RDS_FRAG_SIZE)
to trigger.

For a 4Kb PAGE_SIZE rds_ib_xmit returns min(8240,4096)=4096 when actually
the message contains 8240 bytes. rds_send_xmit thinks there is more to send
and calls rds_ib_xmit again with a data offset "off" of 4096-48(rds header)
=4048 bytes thus hitting the BUG_ON(off & RDS_FRAG_SIZE) [RDS_FRAG_SIZE=4k].

The commit 6094628bfd94323fc1cea05ec2c6affd98c18f7f
"rds: prevent BUG_ON triggering on congestion map updates" introduced
this regression. That change was addressing the triggering of a different
BUG_ON in rds_send_xmit() on PowerPC architecture with 64Kbytes PAGE_SIZE:
 	BUG_ON(ret != 0 &&
    		 conn->c_xmit_sg == rm->data.op_nents);
This was the sequence it was going through:
(rds_ib_xmit)
/* Do not send cong updates to IB loopback */
if (conn->c_loopback
   && rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
  	rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
    	return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES;
}
rds_ib_xmit returns 8240
rds_send_xmit:
  c_xmit_data_off = 0 + 8240 - 48 (rds header accounted only the first time)
   		 = 8192
  c_xmit_data_off < 65536 (sg->length), so calls rds_ib_xmit again
rds_ib_xmit returns 8240
rds_send_xmit:
  c_xmit_data_off = 8192 + 8240 = 16432, calls rds_ib_xmit again
  and so on (c_xmit_data_off 24672,32912,41152,49392,57632)
rds_ib_xmit returns 8240
On this iteration this sequence causes the BUG_ON in rds_send_xmit:
    while (ret) {
    	tmp = min_t(int, ret, sg->length - conn->c_xmit_data_off);
    	[tmp = 65536 - 57632 = 7904]
    	conn->c_xmit_data_off += tmp;
    	[c_xmit_data_off = 57632 + 7904 = 65536]
    	ret -= tmp;
    	[ret = 8240 - 7904 = 336]
    	if (conn->c_xmit_data_off == sg->length) {
    		conn->c_xmit_data_off = 0;
    		sg++;
    		conn->c_xmit_sg++;
    		BUG_ON(ret != 0 &&
    			conn->c_xmit_sg == rm->data.op_nents);
    		[c_xmit_sg = 1, rm->data.op_nents = 1]

What the current fix does:
Since the congestion update over loopback is not actually transmitted
as a message, all that rds_ib_xmit needs to do is let the caller think
the full message has been transmitted and not return partial bytes.
It will return 8240 (RDS_CONG_MAP_BYTES+48) when PAGE_SIZE is 4Kb.
And 64Kb+48 when page size is 64Kb.

Reported-by: Josh Hunt <joshhunt00@gmail.com>
Tested-by: Honggang Li <honli@redhat.com>
Acked-by: Bang Nguyen <bang.nguyen@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
macvtap: Do not double-count received packets

[ Upstream commit 006da7b07bc4d3a7ffabad17cf639eec6849c9dc ]

Currently macvlan will count received packets after calling each
vlans receive handler.   Macvtap attempts to count the packet
yet again when the user reads the packet from the tap socket.
This code doesn't do this consistently either.  Remove the
counting from macvtap and let only macvlan count received
packets.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
macvtap: update file current position

[ Upstream commit e6ebc7f16ca1434a334647aa56399c546be4e64b ]

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tun: update file current position

[ Upstream commit d0b7da8afa079ffe018ab3e92879b7138977fc8f ]

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
macvtap: signal truncated packets

[ Upstream commit ce232ce01d61b184202bb185103d119820e1260c ]

macvtap_put_user() never return a value grater than iov length, this in fact
bypasses the truncated checking in macvtap_recvmsg(). Fix this by always
returning the size of packet plus the possible vlan header to let the trunca
checking work.

Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: don't count addrconf generated routes against gc limit

[ Upstream commit a3300ef4bbb1f1e33ff0400e1e6cf7733d988f4f ]

Brett Ciphery reported that new ipv6 addresses failed to get installed
because the addrconf generated dsts where counted against the dst gc
limit. We don't need to count those routes like we currently don't count
administratively added routes.

Because the max_addresses check enforces a limit on unbounded address
generation first in case someone plays with router advertisments, we
are still safe here.

Reported-by: Brett Ciphery <brett.ciphery@windriver.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: drop_monitor: fix the value of maxattr

[ Upstream commit d323e92cc3f4edd943610557c9ea1bb4bb5056e8 ]

maxattr in genl_family should be used to save the max attribute
type, but not the max command type. Drop monitor doesn't support
any attributes, so we should leave it as zero.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: unix: allow set_peek_off to fail

[ Upstream commit 12663bfc97c8b3fdb292428105dd92d563164050 ]

unix_dgram_recvmsg() will hold the readlock of the socket until recv
is complete.

In the same time, we may try to setsockopt(SO_PEEK_OFF) which will hang until
unix_dgram_recvmsg() will complete (which can take a while) without allowing
us to break out of it, triggering a hung task spew.

Instead, allow set_peek_off to fail, this way userspace will not hang.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>