refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We got a report of yet another bug in ping

http://www.openwall.com/lists/oss-security/2017/03/24/6

->disconnect() is not called with socket lock held.

Fix this by acquiring ping rwlock earlier.

Thanks to Daniel, Alexander and Andrey for letting us know this problem.

Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NDaniel Jiang <danieljiang0415@gmail.com>
Reported-by: NSolar Designer <solar@openwall.com>
Reported-by: NAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrey reported a kernel crash:

  general protection fault: 0000 [#1] SMP KASAN
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in:
  CPU: 2 PID: 3880 Comm: syz-executor1 Not tainted 4.10.0-rc6+ #124
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  task: ffff880060048040 task.stack: ffff880069be8000
  RIP: 0010:ping_v4_push_pending_frames net/ipv4/ping.c:647 [inline]
  RIP: 0010:ping_v4_sendmsg+0x1acd/0x23f0 net/ipv4/ping.c:837
  RSP: 0018:ffff880069bef8b8 EFLAGS: 00010206
  RAX: dffffc0000000000 RBX: ffff880069befb90 RCX: 0000000000000000
  RDX: 0000000000000018 RSI: ffff880069befa30 RDI: 00000000000000c2
  RBP: ffff880069befbb8 R08: 0000000000000008 R09: 0000000000000000
  R10: 0000000000000002 R11: 0000000000000000 R12: ffff880069befab0
  R13: ffff88006c624a80 R14: ffff880069befa70 R15: 0000000000000000
  FS:  00007f6f7c716700(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000004a6f28 CR3: 000000003a134000 CR4: 00000000000006e0
  Call Trace:
   inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744
   sock_sendmsg_nosec net/socket.c:635 [inline]
   sock_sendmsg+0xca/0x110 net/socket.c:645
   SYSC_sendto+0x660/0x810 net/socket.c:1687
   SyS_sendto+0x40/0x50 net/socket.c:1655
   entry_SYSCALL_64_fastpath+0x1f/0xc2

This is because we miss a check for NULL pointer for skb_peek() when
the queue is empty. Other places already have the same check.

Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Reported-by: NAndrey Konovalov <andreyknvl@google.com>
Tested-by: NAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When same struct dst_entry can be used for many different
neighbours we can not use it for pending confirmations.

The datagram protocols can use MSG_CONFIRM to confirm the
neighbour. When used with MSG_PROBE we do not reach the
code where neighbour is confirmed, so we have to do the
same slow lookup by using the dst_confirm_neigh() helper.
When MSG_PROBE is not used, ip_append_data/ip6_append_data
will set the skb flag dst_pending_confirm.
Reported-by: NYueHaibing <yuehaibing@huawei.com>
Fixes: 5110effe ("net: Do delayed neigh confirmation.")
Fixes: f2bb4bed ("ipv4: Cache output routes in fib_info nexthops.")
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The inet_num is u16, so use %hu instead of casting it to int. And
the sk_bound_dev_if is int actually, so it needn't cast to int.
Signed-off-by: NGao Feng <fgao@ikuai8.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Prior to commit c0371da6 ("put iov_iter into msghdr") in v3.19, there
was no check that the iovec contained enough bytes for an ICMP header,
and the read loop would walk across neighboring stack contents. Since the
iov_iter conversion, bad arguments are noticed, but the returned error is
EFAULT. Returning EINVAL is a clearer error and also solves the problem
prior to v3.19.

This was found using trinity with KASAN on v3.18:

BUG: KASAN: stack-out-of-bounds in memcpy_fromiovec+0x60/0x114 at addr ffffffc071077da0
Read of size 8 by task trinity-c2/9623
page:ffffffbe034b9a08 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 0 PID: 9623 Comm: trinity-c2 Tainted: G    BU         3.18.0-dirty #15
Hardware name: Google Tegra210 Smaug Rev 1,3+ (DT)
Call trace:
[<ffffffc000209c98>] dump_backtrace+0x0/0x1ac arch/arm64/kernel/traps.c:90
[<ffffffc000209e54>] show_stack+0x10/0x1c arch/arm64/kernel/traps.c:171
[<     inline     >] __dump_stack lib/dump_stack.c:15
[<ffffffc000f18dc4>] dump_stack+0x7c/0xd0 lib/dump_stack.c:50
[<     inline     >] print_address_description mm/kasan/report.c:147
[<     inline     >] kasan_report_error mm/kasan/report.c:236
[<ffffffc000373dcc>] kasan_report+0x380/0x4b8 mm/kasan/report.c:259
[<     inline     >] check_memory_region mm/kasan/kasan.c:264
[<ffffffc00037352c>] __asan_load8+0x20/0x70 mm/kasan/kasan.c:507
[<ffffffc0005b9624>] memcpy_fromiovec+0x5c/0x114 lib/iovec.c:15
[<     inline     >] memcpy_from_msg include/linux/skbuff.h:2667
[<ffffffc000ddeba0>] ping_common_sendmsg+0x50/0x108 net/ipv4/ping.c:674
[<ffffffc000dded30>] ping_v4_sendmsg+0xd8/0x698 net/ipv4/ping.c:714
[<ffffffc000dc91dc>] inet_sendmsg+0xe0/0x12c net/ipv4/af_inet.c:749
[<     inline     >] __sock_sendmsg_nosec net/socket.c:624
[<     inline     >] __sock_sendmsg net/socket.c:632
[<ffffffc000cab61c>] sock_sendmsg+0x124/0x164 net/socket.c:643
[<     inline     >] SYSC_sendto net/socket.c:1797
[<ffffffc000cad270>] SyS_sendto+0x178/0x1d8 net/socket.c:1761

CVE-2016-8399
Reported-by: NQidan He <i@flanker017.me>
Fixes: c319b4d7 ("net: ipv4: add IPPROTO_ICMP socket kind")
Cc: stable@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- Use the UID in routing lookups made by protocol connect() and
  sendmsg() functions.
- Make sure that routing lookups triggered by incoming packets
  (e.g., Path MTU discovery) take the UID of the socket into
  account.
- For packets not associated with a userspace socket, (e.g., ping
  replies) use UID 0 inside the user namespace corresponding to
  the network namespace the socket belongs to. This allows
  all namespaces to apply routing and iptables rules to
  kernel-originated traffic in that namespaces by matching UID 0.
  This is better than using the UID of the kernel socket that is
  sending the traffic, because the UID of kernel sockets created
  at namespace creation time (e.g., the per-processor ICMP and
  TCP sockets) is the UID of the user that created the socket,
  which might not be mapped in the namespace.

Tested: compiles allnoconfig, allyesconfig, allmodconfig
Tested: https://android-review.googlesource.com/253302Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Baozeng Ding reported KASAN traces showing uses after free in
udp_lib_get_port() and other related UDP functions.

A CONFIG_DEBUG_PAGEALLOC=y kernel would eventually crash.

I could write a reproducer with two threads doing :

static int sock_fd;
static void *thr1(void *arg)
{
	for (;;) {
		connect(sock_fd, (const struct sockaddr *)arg,
			sizeof(struct sockaddr_in));
	}
}

static void *thr2(void *arg)
{
	struct sockaddr_in unspec;

	for (;;) {
		memset(&unspec, 0, sizeof(unspec));
	        connect(sock_fd, (const struct sockaddr *)&unspec,
			sizeof(unspec));
        }
}

Problem is that udp_disconnect() could run without holding socket lock,
and this was causing list corruptions.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NBaozeng Ding <sploving1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current supplementary groups code can massively overallocate memory and
is implemented in a way so that access to individual gid is done via 2D
array.

If number of gids is <= 32, memory allocation is more or less tolerable
(140/148 bytes).  But if it is not, code allocates full page (!)
regardless and, what's even more fun, doesn't reuse small 32-entry
array.

2D array means dependent shifts, loads and LEAs without possibility to
optimize them (gid is never known at compile time).

All of the above is unnecessary.  Switch to the usual
trailing-zero-len-array scheme.  Memory is allocated with
kmalloc/vmalloc() and only as much as needed.  Accesses become simpler
(LEA 8(gi,idx,4) or even without displacement).

Maximum number of gids is 65536 which translates to 256KB+8 bytes.  I
think kernel can handle such allocation.

On my usual desktop system with whole 9 (nine) aux groups, struct
group_info shrinks from 148 bytes to 44 bytes, yay!

Nice side effects:

 - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing,

 - fix little mess in net/ipv4/ping.c
   should have been using GROUP_AT macro but this point becomes moot,

 - aux group allocation is persistent and should be accounted as such.

Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.bySigned-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, SOL_TIMESTAMPING can only be enabled using setsockopt.
This is very costly when users want to sample writes to gather
tx timestamps.

Add support for enabling SO_TIMESTAMPING via control messages by
using tsflags added in `struct sockcm_cookie` (added in the previous
patches in this series) to set the tx_flags of the last skb created in
a sendmsg. With this patch, the timestamp recording bits in tx_flags
of the skbuff is overridden if SO_TIMESTAMPING is passed in a cmsg.

Please note that this is only effective for overriding the recording
timestamps flags. Users should enable timestamp reporting (e.g.,
SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_OPT_ID) using
socket options and then should ask for SOF_TIMESTAMPING_TX_*
using control messages per sendmsg to sample timestamps for each
write.
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Process socket-level control messages by invoking
__sock_cmsg_send in ip_cmsg_send for control messages on
the SOL_SOCKET layer.

This makes sure whenever ip_cmsg_send is called in udp, icmp,
and raw, we also process socket-level control messages.

Note that this commit interprets new control messages that
were ignored before. As such, this commit does not change
the behavior of IPv4 control messages.
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

8cc785f6 ("net: ipv4: make the ping
/proc code AF-independent") removed the code using it, but renamed this
variable instead of removing it.
Signed-off-by: NEric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dmitry reported memory leaks of IP options allocated in
ip_cmsg_send() when/if this function returns an error.

Callers are responsible for the freeing.

Many thanks to Dmitry for the report and diagnostic.
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to support fast reuseport lookups in TCP, the hash function
defined in struct proto must be capable of returning an error code.
This patch changes the function signature of all related hash functions
to return an integer and handles or propagates this return value at
all call sites.
Signed-off-by: NCraig Gallek <kraig@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add lock release/acquire annotations to ping_seq_start() and
ping_seq_stop() to satisfy sparse.
Signed-off-by: NLance Richardson <lrichard@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support to allow non-local binds similar to how this was done for IPv4.
Non-local binds are very useful in emulating the Internet in a box, etc.

This add the ip_nonlocal_bind sysctl under ipv6.

Testing:

Set up nonlocal binding and receive routing on a host, e.g.:

ip -6 rule add from ::/0 iif eth0 lookup 200
ip -6 route add local 2001:0:0:1::/64 dev lo proto kernel scope host table 200
sysctl -w net.ipv6.ip_nonlocal_bind=1

Set up routing to 2001:0:0:1::/64 on peer to go to first host

ping6 -I 2001:0:0:1::1 peer-address -- to verify
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we don't do that, then the poison value is left in the ->pprev
backlink.

This can cause crashes if we do a disconnect, followed by a connect().
Tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reported-by: NWen Xu <hotdog3645@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ipv4 code uses a mixture of coding styles. In some instances check
for non-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>

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>

const qualifiers ease code review by making clear
which objects are not written in a function.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1. For an IPv4 ping socket, ping_check_bind_addr does not check
   the family of the socket address that's passed in. Instead,
   make it behave like inet_bind, which enforces either that the
   address family is AF_INET, or that the family is AF_UNSPEC and
   the address is 0.0.0.0.
2. For an IPv6 ping socket, ping_check_bind_addr returns EINVAL
   if the socket family is not AF_INET6. Return EAFNOSUPPORT
   instead, for consistency with inet6_bind.
3. Make ping_v4_sendmsg and ping_v6_sendmsg return EAFNOSUPPORT
   instead of EINVAL if an incorrect socket address structure is
   passed in.
4. Make IPv6 ping sockets be IPv6-only. The code does not support
   IPv4, and it cannot easily be made to support IPv4 because
   the protocol numbers for ICMP and ICMPv6 are different. This
   makes connect(::ffff:192.0.2.1) fail with EAFNOSUPPORT instead
   of making the socket unusable.

Among other things, this fixes an oops that can be triggered by:

    int s = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
    struct sockaddr_in6 sin6 = {
        .sin6_family = AF_INET6,
        .sin6_addr = in6addr_any,
    };
    bind(s, (struct sockaddr *) &sin6, sizeof(sin6));

Change-Id: If06ca86d9f1e4593c0d6df174caca3487c57a241
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.

Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

That takes care of the majority of ->sendmsg() instances - most of them
via memcpy_to_msg() or assorted getfrag() callbacks.  One place where we
still keep memcpy_fromiovecend() is tipc - there we potentially read the
same data over and over; separate patch, that...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... instead of storing its ->mgs_iter.iov there
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

An exception is seen in ICMP ping receive path where the skb
destructor sock_rfree() tries to access a freed socket. This happens
because ping_rcv() releases socket reference with sock_put() and this
internally frees up the socket. Later icmp_rcv() will try to free the
skb and as part of this, skb destructor is called and which leads
to a kernel panic as the socket is freed already in ping_rcv().

-->|exception
-007|sk_mem_uncharge
-007|sock_rfree
-008|skb_release_head_state
-009|skb_release_all
-009|__kfree_skb
-010|kfree_skb
-011|icmp_rcv
-012|ip_local_deliver_finish

Fix this incorrect free by cloning this skb and processing this cloned
skb instead.

This patch was suggested by Eric Dumazet
Signed-off-by: NSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

TCP timestamping introduced MSG_ERRQUEUE handling for TCP sockets.
If the socket is of family AF_INET6, call ipv6_recv_error instead
of ip_recv_error.

This change is more complex than a single branch due to the loadable
ipv6 module. It reuses a pre-existing indirect function call from
ping. The ping code is safe to call, because it is part of the core
ipv6 module and always present when AF_INET6 sockets are active.

Fixes: 4ed2d765 (net-timestamp: TCP timestamping)
Signed-off-by: NWillem de Bruijn <willemb@google.com>

----

It may also be worthwhile to add WARN_ON_ONCE(sk->family == AF_INET6)
to ip_recv_error.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ping_lookup() may return a wrong sock if sk_buff's and sock's protocols
dont' match. For example, sk_buff's protocol is ETH_P_IPV6, but sock's
sk_family is AF_INET, in that case, if sk->sk_bound_dev_if is zero, a wrong
sock will be returned.
the fix is to "continue" the searching, if no matching, return NULL.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: NJane Zhou <a17711@motorola.com>
Signed-off-by: NYiwei Zhao <gbjc64@motorola.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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>

This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".

When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.

Having a helper like this means there will be less places to touch
during that transformation.

Based upon descriptions and patch from Al Viro.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net.ipv4.ip_nonlocal_bind sysctl was global to all network
namespaces. This patch allows to set a different value for each
network namespace.
Signed-off-by: NVincent Bernat <vincent@bernat.im>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similarly, when CONFIG_SYSCTL is not set, ping_group_range should still
work, just that no one can change it. Therefore we should move it out of
sysctl_net_ipv4.c. And, it should not share the same seqlock with
ip_local_port_range.

BTW, rename it to ->ping_group_range instead.

Cc: David S. Miller <davem@davemloft.net>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Reported-by: NStefan de Konink <stefan@konink.de>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When CONFIG_SYSCTL is not set, ip_local_port_range should still work,
just that no one can change it. Therefore we should move it out of sysctl_inet.c.
Also, rename it to ->ip_local_ports instead.

Cc: David S. Miller <davem@davemloft.net>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Reported-by: NStefan de Konink <stefan@konink.de>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Plug a group_info refcount leak in ping_init.
group_info is only needed during initialization and
the code failed to release the reference on exit.
While here move grabbing the reference to a place
where it is actually needed.
Signed-off-by: NChuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: NZhang Dongxing <dongxing.zhang@intel.com>
Signed-off-by: Nxiaoming wang <xiaoming.wang@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NGert Doering <gert@space.net>
Cc: Tore Anderson <tore@fud.no>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some ipv6 protocols cannot handle ipv4 addresses, so we must not allow
connecting and binding to them. sendmsg logic does already check msg->name
for this but must trust already connected sockets which could be set up
for connection to ipv4 address family.

Per-socket flag ipv6only is of no use here, as it is under users control
by setsockopt.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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