linux.git/include/net/ip.h, branch v3.15

ipv4: add a sock pointer to dst->output() path.

2014-04-15T17:47:15+00:00

In the dst->output() path for ipv4, the code assumes the skb it has to
transmit is attached to an inet socket, specifically via
ip_mc_output() : The sk_mc_loop() test triggers a WARN_ON() when the
provider of the packet is an AF_PACKET socket.

The dst->output() method gets an additional 'struct sock *sk'
parameter. This needs a cascade of changes so that this parameter can
be propagated from vxlan to final consumer.

Fixes: 8f646c922d55 ("vxlan: keep original skb ownership")
Reported-by: lucien xin 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ipv4: add a sock pointer to ip_queue_xmit()

2014-04-15T16:58:34+00:00

ip_queue_xmit() assumes the skb it has to transmit is attached to an
inet socket. Commit 31c70d5956fc ("l2tp: keep original skb ownership")
changed l2tp to not change skb ownership and thus broke this assumption.

One fix is to add a new 'struct sock *sk' parameter to ip_queue_xmit(),
so that we do not assume skb->sk points to the socket used by l2tp
tunnel.

Fixes: 31c70d5956fc ("l2tp: keep original skb ownership")
Reported-by: Zhan Jianyu 
Tested-by: Zhan Jianyu 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

tcp: Use NET_ADD_STATS instead of NET_ADD_STATS_BH in tcp_event_new_data_sent()

2014-03-06T20:19:43+00:00

Can be invoked from non-BH context.

Based upon a patch by Eric Dumazet.

Fixes: f19c29e3e391 ("tcp: snmp stats for Fast Open, SYN rtx, and data pkts")
Reported-by: Sergey Senozhatsky 
Signed-off-by: David S. Miller

ipv4: yet another new IP_MTU_DISCOVER option IP_PMTUDISC_OMIT

2014-02-26T20:51:00+00:00

IP_PMTUDISC_INTERFACE has a design error: because it does not allow the
generation of fragments if the interface mtu is exceeded, it is very
hard to make use of this option in already deployed name server software
for which I introduced this option.

This patch adds yet another new IP_MTU_DISCOVER option to not honor any
path mtu information and not accepting new icmp notifications destined for
the socket this option is enabled on. But we allow outgoing fragmentation
in case the packet size exceeds the outgoing interface mtu.

As such this new option can be used as a drop-in replacement for
IP_PMTUDISC_DONT, which is currently in use by most name server software
making the adoption of this option very smooth and easy.

The original advantage of IP_PMTUDISC_INTERFACE is still maintained:
ignoring incoming path MTU updates and not honoring discovered path MTUs
in the output path.

Fixes: 482fc6094afad5 ("ipv4: introduce new IP_MTU_DISCOVER mode IP_PMTUDISC_INTERFACE")
Cc: Florian Weimer 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv6: honor IPV6_PKTINFO with v4 mapped addresses on sendmsg

2014-02-19T21:28:42+00:00

In case we decide in udp6_sendmsg to send the packet down the ipv4
udp_sendmsg path because the destination is either of family AF_INET or
the destination is an ipv4 mapped ipv6 address, we don't honor the
maybe specified ipv4 mapped ipv6 address in IPV6_PKTINFO.

We simply can check for this option in ip_cmsg_send because no calls to
ipv6 module functions are needed to do so.

Reported-by: Gert Doering 
Cc: Tore Anderson 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams

2014-01-20T03:53:18+00:00

We currently don't report IPV6_RECVPKTINFO in cmsg access ancillary data
for IPv4 datagrams on IPv6 sockets.

This patch splits the ip6_datagram_recv_ctl into two functions, one
which handles both protocol families, AF_INET and AF_INET6, while the
ip6_datagram_recv_specific_ctl only handles IPv6 cmsg data.

ip6_datagram_recv_*_ctl never reported back any errors, so we can make
them return void. Also provide a helper for protocols which don't offer dual
personality to further use ip6_datagram_recv_ctl, which is exported to
modules.

I needed to shuffle the code for ping around a bit to make it easier to
implement dual personality for ping ipv6 sockets in future.

Reported-by: Gert Doering 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv4: register igmp_notifier even when !CONFIG_PROC_FS

2014-01-14T23:03:33+00:00

We still need this notifier even when we don't config
PROC_FS.

It should be rare to have a kernel without PROC_FS,
so just for completeness.

Cc: Stephen Hemminger 
Cc: David S. Miller 
Cc: Patrick McHardy 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing

2014-01-13T19:22:54+00:00

While forwarding we should not use the protocol path mtu to calculate
the mtu for a forwarded packet but instead use the interface mtu.

We mark forwarded skbs in ip_forward with IPSKB_FORWARDED, which was
introduced for multicast forwarding. But as it does not conflict with
our usage in unicast code path it is perfect for reuse.

I moved the functions ip_sk_accept_pmtu, ip_sk_use_pmtu and ip_skb_dst_mtu
along with the new ip_dst_mtu_maybe_forward to net/ip.h to fix circular
dependencies because of IPSKB_FORWARDED.

Because someone might have written a software which does probe
destinations manually and expects the kernel to honour those path mtus
I introduced a new per-namespace "ip_forward_use_pmtu" knob so someone
can disable this new behaviour. We also still use mtus which are locked on a
route for forwarding.

The reason for this change is, that path mtus information can be injected
into the kernel via e.g. icmp_err protocol handler without verification
of local sockets. As such, this could cause the IPv4 forwarding path to
wrongfully emit fragmentation needed notifications or start to fragment
packets along a path.

Tunnel and ipsec output paths clear IPCB again, thus IPSKB_FORWARDED
won't be set and further fragmentation logic will use the path mtu to
determine the fragmentation size. They also recheck packet size with
help of path mtu discovery and report appropriate errors.

Cc: Eric Dumazet 
Cc: David Miller 
Cc: John Heffner 
Cc: Steffen Klassert 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

inet: make no_pmtu_disc per namespace and kill ipv4_config

2013-12-18T21:58:20+00:00

The other field in ipv4_config, log_martians, was converted to a
per-interface setting, so we can just remove the whole structure.

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

inet: fix addr_len/msg->msg_namelen assignment in recv_error and rxpmtu functions

2013-11-23T22:46:23+00:00

Commit bceaa90240b6019ed73b49965eac7d167610be69 ("inet: prevent leakage
of uninitialized memory to user in recv syscalls") conditionally updated
addr_len if the msg_name is written to. The recv_error and rxpmtu
functions relied on the recvmsg functions to set up addr_len before.

As this does not happen any more we have to pass addr_len to those
functions as well and set it to the size of the corresponding sockaddr
length.

This broke traceroute and such.

Fixes: bceaa90240b6 ("inet: prevent leakage of uninitialized memory to user in recv syscalls")
Reported-by: Brad Spengler 
Reported-by: Tom Labanowski
Cc: mpb 
Cc: David S. Miller 
Cc: Eric Dumazet 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller