This patch allows configuring how the source address of ICMP
redirect messages is selected; by default the old behaviour is
retained, while setting icmp_redirects_use_orig_daddr force the
usage of the destination address of the packet that caused the
redirect.

The new behaviour fits closely the RFC 5798 section 8.1.1, and fix the
following scenario:

Two machines are set up with VRRP to act as routers out of a subnet,
they have IPs x.x.x.1/24 and x.x.x.2/24, with VRRP holding on to
x.x.x.254/24.

If a host in said subnet needs to get an ICMP redirect from the VRRP
router, i.e. to reach a destination behind a different gateway, the
source IP in the ICMP redirect is chosen as the primary IP on the
interface that the packet arrived at, i.e. x.x.x.1 or x.x.x.2.

The host will then ignore said redirect, due to RFC 1122 section 3.2.2.2,
and will continue to use the wrong next-op.
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ICMP packets are inspected to let them route together with the flow they
belong to, minimizing the chance that a problematic path will affect flows
on other paths, and so that anycast environments can work with ECMP.
Signed-off-by: NPeter Nørlund <pch@ordbogen.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace calls to vrf_master_ifindex_rcu and vrf_master_ifindex with either
l3mdev_master_ifindex_rcu or l3mdev_master_ifindex.

The pattern:
    oif = vrf_master_ifindex(dev) ? : dev->ifindex;
is replaced with
    oif = l3mdev_fib_oif(dev);

And remove the now unused vrf macros.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrey reported a panic:

[ 7249.865507] BUG: unable to handle kernel pointer dereference at 000000b4
[ 7249.865559] IP: [<c16afeca>] icmp_route_lookup+0xaa/0x320
[ 7249.865598] *pdpt = 0000000030f7f001 *pde = 0000000000000000
[ 7249.865637] Oops: 0000 [#1]
...
[ 7249.866811] CPU: 0 PID: 0 Comm: swapper/0 Not tainted
4.3.0-999-generic #201509220155
[ 7249.866876] Hardware name: MSI MS-7250/MS-7250, BIOS 080014  08/02/2006
[ 7249.866916] task: c1a5ab00 ti: c1a52000 task.ti: c1a52000
[ 7249.866949] EIP: 0060:[<c16afeca>] EFLAGS: 00210246 CPU: 0
[ 7249.866981] EIP is at icmp_route_lookup+0xaa/0x320
[ 7249.867012] EAX: 00000000 EBX: f483ba48 ECX: 00000000 EDX: f2e18a00
[ 7249.867045] ESI: 000000c0 EDI: f483ba70 EBP: f483b9ec ESP: f483b974
[ 7249.867077]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 7249.867108] CR0: 8005003b CR2: 000000b4 CR3: 36ee07c0 CR4: 000006f0
[ 7249.867141] Stack:
[ 7249.867165]  320310ee 00000000 00000042 320310ee 00000000 c1aeca00
f3920240 f0c69180
[ 7249.867268]  f483ba04 f855058b a89b66cd f483ba44 f8962f4b 00000000
e659266c f483ba54
[ 7249.867361]  8004753c f483ba5c f8962f4b f2031140 000003c1 ffbd8fa0
c16b0e00 00000064
[ 7249.867448] Call Trace:
[ 7249.867494]  [<f855058b>] ? e1000_xmit_frame+0x87b/0xdc0 [e1000e]
[ 7249.867534]  [<f8962f4b>] ? tcp_in_window+0xeb/0xb10 [nf_conntrack]
[ 7249.867576]  [<f8962f4b>] ? tcp_in_window+0xeb/0xb10 [nf_conntrack]
[ 7249.867615]  [<c16b0e00>] ? icmp_send+0xa0/0x380
[ 7249.867648]  [<c16b102f>] icmp_send+0x2cf/0x380
[ 7249.867681]  [<f89c8126>] nf_send_unreach+0xa6/0xc0 [nf_reject_ipv4]
[ 7249.867714]  [<f89cd0da>] reject_tg+0x7a/0x9f [ipt_REJECT]
[ 7249.867746]  [<f88c29a7>] ipt_do_table+0x317/0x70c [ip_tables]
[ 7249.867780]  [<f895e0a6>] ? __nf_conntrack_find_get+0x166/0x3b0
[nf_conntrack]
[ 7249.867838]  [<f895eea8>] ? nf_conntrack_in+0x398/0x600 [nf_conntrack]
[ 7249.867889]  [<f84c0035>] iptable_filter_hook+0x35/0x80 [iptable_filter]
[ 7249.867933]  [<c16776a1>] nf_iterate+0x71/0x80
[ 7249.867970]  [<c1677715>] nf_hook_slow+0x65/0xc0
[ 7249.868002]  [<c1681811>] __ip_local_out_sk+0xc1/0xd0
[ 7249.868034]  [<c1680f30>] ? ip_forward_options+0x1a0/0x1a0
[ 7249.868066]  [<c1681836>] ip_local_out_sk+0x16/0x30
[ 7249.868097]  [<c1684054>] ip_send_skb+0x14/0x80
[ 7249.868129]  [<c16840f4>] ip_push_pending_frames+0x34/0x40
[ 7249.868163]  [<c16844a2>] ip_send_unicast_reply+0x282/0x310
[ 7249.868196]  [<c16a0863>] tcp_v4_send_reset+0x1b3/0x380
[ 7249.868227]  [<c16a1b63>] tcp_v4_rcv+0x323/0x990
[ 7249.868257]  [<c16776a1>] ? nf_iterate+0x71/0x80
[ 7249.868289]  [<c167dc2b>] ip_local_deliver_finish+0x8b/0x230
[ 7249.868322]  [<c167df4c>] ip_local_deliver+0x4c/0xa0
[ 7249.868353]  [<c167dba0>] ? ip_rcv_finish+0x390/0x390
[ 7249.868384]  [<c167d88c>] ip_rcv_finish+0x7c/0x390
[ 7249.868415]  [<c167e280>] ip_rcv+0x2e0/0x420
...

Prior to the VRF change the oif was not set in the flow struct, so the
VRF support should really have only added the vrf_master_ifindex lookup.

Fixes: 613d09b3 ("net: Use VRF device index for lookups on TX")
Cc: Andrey Melnikov <temnota.am@gmail.com>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

inetpeer caches based on address only, so duplicate IP addresses within
a namespace return the same cached entry. Enhance the ipv4 address key
to contain both the IPv4 address and VRF device index.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While running net-next I hit this:
[  634.073119] ===============================
[  634.073150] [ INFO: suspicious RCU usage. ]
[  634.073182] 4.2.0-rc6+ #45 Not tainted
[  634.073213] -------------------------------
[  634.073244] include/net/vrf.h:38 suspicious rcu_dereference_check()
usage!
[  634.073274]
               other info that might help us debug this:

[  634.073307]
               rcu_scheduler_active = 1, debug_locks = 1
[  634.073338] 2 locks held by swapper/0/0:
[  634.073369]  #0:  (((&n->timer))){+.-...}, at: [<ffffffff8112bc35>]
call_timer_fn+0x5/0x480
[  634.073412]  #1:  (slock-AF_INET){+.-...}, at: [<ffffffff8174f0f5>]
icmp_send+0x155/0x5f0
[  634.073450]
               stack backtrace:
[  634.073483] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc6+ #45
[  634.073514] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS
VirtualBox 12/01/2006
[  634.073545]  0000000000000000 0593ba8242d9ace4 ffff88002fc03b48
ffffffff81803f1b
[  634.073612]  0000000000000000 ffffffff81e12500 ffff88002fc03b78
ffffffff811003c5
[  634.073642]  0000000000000000 ffff88002ec4e600 ffffffff81f00f80
ffff88002fc03cf0
[  634.073669] Call Trace:
[  634.073694]  <IRQ>  [<ffffffff81803f1b>] dump_stack+0x4c/0x65
[  634.073728]  [<ffffffff811003c5>] lockdep_rcu_suspicious+0xc5/0x100
[  634.073763]  [<ffffffff8174eb56>] icmp_route_lookup+0x176/0x5c0
[  634.073793]  [<ffffffff8174f2fb>] ? icmp_send+0x35b/0x5f0
[  634.073818]  [<ffffffff8174f274>] ? icmp_send+0x2d4/0x5f0
[  634.073844]  [<ffffffff8174f3ce>] icmp_send+0x42e/0x5f0
[  634.073873]  [<ffffffff8170b662>] ipv4_link_failure+0x22/0xa0
[  634.073899]  [<ffffffff8174bdda>] arp_error_report+0x3a/0x80
[  634.073926]  [<ffffffff816d6100>] ? neigh_lookup+0x2c0/0x2c0
[  634.073952]  [<ffffffff816d396e>] neigh_invalidate+0x8e/0x110
[  634.073984]  [<ffffffff816d62ae>] neigh_timer_handler+0x1ae/0x290
[  634.074013]  [<ffffffff816d6100>] ? neigh_lookup+0x2c0/0x2c0
[  634.074013]  [<ffffffff8112bce3>] call_timer_fn+0xb3/0x480
[  634.074013]  [<ffffffff8112bc35>] ? call_timer_fn+0x5/0x480
[  634.074013]  [<ffffffff816d6100>] ? neigh_lookup+0x2c0/0x2c0
[  634.074013]  [<ffffffff8112c2bc>] run_timer_softirq+0x20c/0x430
[  634.074013]  [<ffffffff810af50e>] __do_softirq+0xde/0x630
[  634.074013]  [<ffffffff810afc97>] irq_exit+0x117/0x120
[  634.074013]  [<ffffffff81810976>] smp_apic_timer_interrupt+0x46/0x60
[  634.074013]  [<ffffffff8180e950>] apic_timer_interrupt+0x70/0x80
[  634.074013]  <EOI>  [<ffffffff8106b9d6>] ? native_safe_halt+0x6/0x10
[  634.074013]  [<ffffffff81101d8d>] ? trace_hardirqs_on+0xd/0x10
[  634.074013]  [<ffffffff81027d43>] default_idle+0x23/0x200
[  634.074013]  [<ffffffff8102852f>] arch_cpu_idle+0xf/0x20
[  634.074013]  [<ffffffff810f89ba>] default_idle_call+0x2a/0x40
[  634.074013]  [<ffffffff810f8dcc>] cpu_startup_entry+0x39c/0x4c0
[  634.074013]  [<ffffffff817f9cad>] rest_init+0x13d/0x150
[  634.074013]  [<ffffffff81f69038>] start_kernel+0x4a8/0x4c9
[  634.074013]  [<ffffffff81f68120>] ?
early_idt_handler_array+0x120/0x120
[  634.074013]  [<ffffffff81f68339>] x86_64_start_reservations+0x2a/0x2c
[  634.074013]  [<ffffffff81f68485>] x86_64_start_kernel+0x14a/0x16d

It would seem vrf_master_ifindex_rcu() can be called without RCU held in
other contexts as well so introduce a new helper which acquires rcu and
returns the ifindex.
Also add curly braces around both the "if" and "else" parts as per the
style guide.
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently inet_addr_type and inet_dev_addr_type expect local addresses
to be in the local table. With the VRF device local routes for devices
associated with a VRF will be in the table associated with the VRF.
Provide an alternate inet_addr lookup to use a specific table rather
than defaulting to the local table.

inet_addr_type_dev_table keeps the same semantics as inet_addr_type but
if the passed in device is enslaved to a VRF then the table for that VRF
is used for the lookup.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As with ingress use the index of VRF master device for route lookups on
egress. However, the oif should only be used to direct the lookups to a
specific table. Routes in the table are not based on the VRF device but
rather interfaces that are part of the VRF so do not consider the oif for
lookups within the table. The FLOWI_FLAG_VRFSRC is used to control this
latter part.
Signed-off-by: NShrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip_route_input() unconditionally overwrites the dst. Hide the original
dst attached to the skb by calling skb_dst_set(skb, NULL) prior to
ip_route_input().
Reported-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ipv4 code uses a mixture of coding styles. In some instances check
for NULL pointer is done as x == NULL and sometimes as !x. !x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.
Signed-off-by: NIan Morris <ipm@chirality.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Get rid of nr_cpu_ids and use modern percpu allocation.

Note that the sockets themselves are not yet allocated
using NUMA affinity.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If icmp_rcv() has successfully processed the incoming ICMP datagram, we
should use consume_skb() rather than kfree_skb() because a hit on the likes
of perf -e skb:kfree_skb is not called-for.
Signed-off-by: NRick Jones <rick.jones2@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the more common dynamic_debug capable net_dbg_ratelimited
and remove the LIMIT_NETDEBUG macro.

All messages are still ratelimited.

Some KERN_<LEVEL> uses are changed to KERN_DEBUG.

This may have some negative impact on messages that were
emitted at KERN_INFO that are not not enabled at all unless
DEBUG is defined or dynamic_debug is enabled.  Even so,
these messages are now _not_ emitted by default.

This also eliminates the use of the net_msg_warn sysctl
"/proc/sys/net/core/warnings".  For backward compatibility,
the sysctl is not removed, but it has no function.  The extern
declaration of net_msg_warn is removed from sock.h and made
static in net/core/sysctl_net_core.c

Miscellanea:

o Update the sysctl documentation
o Remove the embedded uses of pr_fmt
o Coalesce format fragments
o Realign arguments
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current ICMP rate limiting uses inetpeer cache, which is an RBL tree
protected by a lock, meaning that hosts can be stuck hard if all cpus
want to check ICMP limits.

When say a DNS or NTP server process is restarted, inetpeer tree grows
quick and machine comes to its knees.

iptables can not help because the bottleneck happens before ICMP
messages are even cooked and sent.

This patch adds a new global limitation, using a token bucket filter,
controlled by two new sysctl :

icmp_msgs_per_sec - INTEGER
    Limit maximal number of ICMP packets sent per second from this host.
    Only messages whose type matches icmp_ratemask are
    controlled by this limit.
    Default: 1000

icmp_msgs_burst - INTEGER
    icmp_msgs_per_sec controls number of ICMP packets sent per second,
    while icmp_msgs_burst controls the burst size of these packets.
    Default: 50

Note that if we really want to send millions of ICMP messages per
second, we might extend idea and infra added in commit 04ca6973
("ip: make IP identifiers less predictable") :
add a token bucket in the ip_idents hash and no longer rely on inetpeer.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip_local_deliver_finish() already have a rcu_read_lock/unlock, so
the rcu_read_lock/unlock is unnecessary.

See the stack below:
ip_local_deliver_finish
	|
	|
	->icmp_rcv
		|
		|
		->icmp_socket_deliver
Suggested-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When dealing with ICMPv[46] Error Message, function icmp_socket_deliver()
and icmpv6_notify() do some valid checks on packet's length, but then some
protocols check packet's length redaudantly. So remove those duplicated
statements, and increase counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORS in
function icmp_socket_deliver() and icmpv6_notify() respectively.

In addition, add missed counter in udp6/udplite6 when socket is NULL.
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some older router implementations still send Fragmentation Needed
errors with the Next-Hop MTU field set to zero. This is explicitly
described as an eventuality that hosts must deal with by the
standard (RFC 1191) since older standards specified that those
bits must be zero.

Linux had a generic (for all of IPv4) implementation of the algorithm
described in the RFC for searching a list of MTU plateaus for a good
value. Commit 46517008 ("ipv4: Kill ip_rt_frag_needed().")
removed this as part of the changes to remove the routing cache.
Subsequently any Fragmentation Needed packet with a zero Next-Hop
MTU has been discarded without being passed to the per-protocol
handlers or notifying userspace for raw sockets.

When there is a router which does not implement RFC 1191 on an
MTU limited path then this results in stalled connections since
large packets are discarded and the local protocols are not
notified so they never attempt to lower the pMTU.

One example I have seen is an OpenBSD router terminating IPSec
tunnels. It's worth pointing out that this case is distinct from
the BSD 4.2 bug which incorrectly calculated the Next-Hop MTU
since the commit in question dismissed that as a valid concern.

All of the per-protocols handlers implement the simple approach from
RFC 1191 of immediately falling back to the minimum value. Although
this is sub-optimal it is vastly preferable to connections hanging
indefinitely.

Remove the Next-Hop MTU != 0 check and allow such packets
to follow the normal path.

Fixes: 46517008 ("ipv4: Kill ip_rt_frag_needed().")
Signed-off-by: NEdward Allcutt <edward.allcutt@openmarket.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Kernel-originated IP packets that have no user socket associated
with them (e.g., ICMP errors and echo replies, TCP RSTs, etc.)
are emitted with a mark of zero. Add a sysctl to make them have
the same mark as the packet they are replying to.

This allows an administrator that wishes to do so to use
mark-based routing, firewalling, etc. for these replies by
marking the original packets inbound.

Tested using user-mode linux:
 - ICMP/ICMPv6 echo replies and errors.
 - TCP RST packets (IPv4 and IPv6).
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use skb_checksum_simple_validate to verify checksum.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This new ip_no_pmtu_disc mode only allowes fragmentation-needed errors
to be honored by protocols which do more stringent validation on the
ICMP's packet payload. This knob is useful for people who e.g. want to
run an unmodified DNS server in a namespace where they need to use pmtu
for TCP connections (as they are used for zone transfers or fallback
for requests) but don't want to use possibly spoofed UDP pmtu information.

Currently the whitelisted protocols are TCP, SCTP and DCCP as they check
if the returned packet is in the window or if the association is valid.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: John Heffner <johnwheffner@gmail.com>
Suggested-by: NFlorian Weimer <fweimer@redhat.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This new mode discards all incoming fragmentation-needed notifications
as I guess was originally intended with this knob. To not break backward
compatibility too much, I only added a special case for mode 2 in the
receiving path.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If IP_TOS or IP_TTL are specified as ancillary data, then sendmsg() sends out
packets with the specified TTL or TOS overriding the socket values specified
with the traditional setsockopt().

The struct inet_cork stores the values of TOS, TTL and priority that are
passed through the struct ipcm_cookie. If there are user-specified TOS
(tos != -1) or TTL (ttl != 0) in the struct ipcm_cookie, these values are
used to override the per-socket values. In case of TOS also the priority
is changed accordingly.

Two helper functions get_rttos and get_rtconn_flags are defined to take
into account the presence of a user specified TOS value when computing
RT_TOS and RT_CONN_FLAGS.
Signed-off-by: NFrancesco Fusco <ffusco@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct icmp_bxm is a large struct, reduce stack usage
by allocating it on heap.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ICMP_PARAMETERPROB is handled by icmp_unreach(); This patch adds
ICMP_PARAMETERPROB to the list of ICMP message types handled by icmp_unreach().
Signed-off-by: NRami Rosen <ramirose@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that comparisons and calculations are always made using pointers.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds the ability to send ICMPv6 echo requests without a
raw socket. The equivalent ability for ICMPv4 was added in
2011.

Instead of having separate code paths for IPv4 and IPv6, make
most of the code in net/ipv4/ping.c dual-stack and only add a
few IPv6-specific bits (like the protocol definition) to a new
net/ipv6/ping.c. Hopefully this will reduce divergence and/or
duplication of bugs in the future.

Caveats:

- Setting options via ancillary data (e.g., using IPV6_PKTINFO
  to specify the outgoing interface) is not yet supported.
- There are no separate security settings for IPv4 and IPv6;
  everything is controlled by /proc/net/ipv4/ping_group_range.
- The proc interface does not yet display IPv6 ping sockets
  properly.

Tested with a patched copy of ping6 and using raw socket calls.
Compiles and works with all of CONFIG_IPV6={n,m,y}.
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add MIB counters for checksum errors in IP layer,
and TCP/UDP/ICMP layers, to help diagnose problems.

$ nstat -a | grep  Csum
IcmpInCsumErrors                72                 0.0
TcpInCsumErrors                 382                0.0
UdpInCsumErrors                 463221             0.0
Icmp6InCsumErrors               75                 0.0
Udp6InCsumErrors                173442             0.0
IpExtInCsumErrors               10884              0.0
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now we handle icmp errors in each transport protocol's err_handler,
for icmp protocols, that is ping_err. Since this handler only care
of those icmp errors triggered by echo request, errors triggered
by echo reply(which sent by kernel) are sliently ignored.

So wrap ping_err() with icmp_err() to deal with those icmp errors.
Signed-off-by: NLi Wei <lw@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

inet_getpeer_v4() can return NULL under OOM conditions, and while
inet_peer_xrlim_allow() is OK with a NULL peer, inet_putpeer() will
crash.

This code path now uses the same idiom as the others from:
1d861aa4 ("inet: Minimize use of
cached route inetpeer.").
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use inet_iif() consistently, and for TCP record the input interface of
cached RX dst in inet sock.

rt->rt_iif is going to be encoded differently, so that we can
legitimately cache input routes in the FIB info more aggressively.

When the input interface is "use SKB device index" the rt->rt_iif will
be set to zero.

This forces us to move the TCP RX dst cache installation into the ipv4
specific code, and as well it should since doing the route caching for
ipv6 is pointless at the moment since it is not inspected in the ipv6
input paths yet.

Also, remove the unlikely on dst->obsolete, all ipv4 dsts have
obsolete set to a non-zero value to force invocation of the check
callback.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Alexey removed kernel side support for requests, and the
only thing we do for replies is log a message if something
doesn't look right.

As Alexey's comment indicates, this belongs in userspace (if
anywhere), and thus we can safely just get rid of this code.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All handler->err() routines expect that we've done a pskb_may_pull()
test to make sure that IP header length + 8 bytes can be safely
pulled.
Reported-by: NHiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No longer needed, as the protocol handlers now all properly
propagate the redirect back into the routing code.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass in the SKB rather than just the IP addresses, so that policy
and other aspects can reside in ip_rt_redirect() rather then
icmp_redirect().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And thus, we can remove the ping_err() hack.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only use it in the absolutely required cases:

1) COW'ing metrics

2) ipv4 PMTU

3) ipv4 redirects
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The specific destination is the host we direct unicast replies to.
Usually this is the original packet source address, but if we are
responding to a multicast or broadcast packet we have to use something
different.

Specifically we must use the source address we would use if we were to
send a packet to the unicast source of the original packet.

The routing cache precomputes this value, but we want to remove that
precomputation because it creates a hard dependency on the expensive
rpfilter source address validation which we'd like to make cheaper.

There are only three places where this matters:

1) ICMP replies.

2) pktinfo CMSG

3) IP options

Now there will be no real users of rt->rt_spec_dst and we can simply
remove it altogether.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't pretend that inet_protos[] and inet6_protos[] are hashes, thay
are just a straight arrays.  Remove all unnecessary hash masking.

Document MAX_INET_PROTOS.

Use RAW_HTABLE_SIZE when appropriate.
Reported-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>