This patch is to add support for MSG_MORE on sctp.

It adds force_delay in sctp_datamsg to save MSG_MORE, and sets it after
creating datamsg according to the send flag. sctp_packet_can_append_data
then uses it to decide if the chunks of this msg will be sent at once or
delay it.

Note that unlike [1], this patch saves MSG_MORE in datamsg, instead of
in assoc. As sctp enqueues the chunks first, then dequeue them one by
one. If it's saved in assoc,the current msg's send flag (MSG_MORE) may
affect other chunks' bundling.

Since last patch, sctp flush out queue once assoc state falls into
SHUTDOWN_PENDING, the close block problem mentioned in [1] has been
solved as well.

[1] https://patchwork.ozlabs.org/patch/372404/Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now when sending a packet, sctp_transport_dst_check will check if dst
is obsolete by calling ipv4/ip6_dst_check. But they return obsolete
only when adding a new cache, after that when the cache's pmtu is
updated again, it will not trigger transport->dst/pmtu's update.

It can be reproduced by reducing route's pmtu twice. At the 1st time
client will add a new cache, and transport->pathmtu gets updated as
sctp_transport_dst_check finds it's obsolete. But at the 2nd time,
cache's mtu is updated, sctp client will never send out any packet,
because transport->pmtu has no chance to update.

This patch is to fix this by also checking if transport pmtu is dst
mtu in sctp_transport_dst_check, so that transport->pmtu can be
updated on time.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add reconf chunk event based on the sctp event
frame in rx path, it will call sctp_sf_do_reconf to process the
reconf chunk.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add a function to process the incoming reconf chunk,
in which it verifies the chunk, and traverses the param and process
it with the right function one by one.

sctp_sf_do_reconf would be the process function of reconf chunk event.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add a function sctp_verify_reconf to do some length
check and multi-params check for sctp stream reconf according to rfc6525
section 3.1.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to implement Receiver-Side Procedures for the Incoming
SSN Reset Request Parameter described in rfc6525 section 5.2.3.

It's also to move str_list endian conversion out of sctp_make_strreset_req,
so that sctp_make_strreset_req can be used more conveniently to process
inreq.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to implement Receiver-Side Procedures for the Outgoing
SSN Reset Request Parameter described in rfc6525 section 5.2.2.

Note that some checks must be after request_seq check, as even those
checks fail, strreset_inseq still has to be increase by 1.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add Stream Reset Event described in rfc6525
section 6.1.1.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to define Re-configuration Response Parameter described
in rfc6525 section 4.4. As optional fields are only for SSN/TSN Reset
Request Parameter, it uses another function to make that.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to implement Sender-Side Procedures for the Add
Outgoing and Incoming Streams Request Parameter described in
rfc6525 section 5.1.5-5.1.6.

It is also to add sockopt SCTP_ADD_STREAMS in rfc6525 section
6.3.4 for users.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to define Add Incoming/Outgoing Streams Request
Parameter described in rfc6525 section 4.5 and 4.6. They can
be in one same chunk trunk as rfc6525 section 3.1-7 describes,
so make them in one function.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to implement Sender-Side Procedures for the SSN/TSN
Reset Request Parameter descibed in rfc6525 section 5.1.4.

It is also to add sockopt SCTP_RESET_ASSOC in rfc6525 section 6.3.3
for users.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to define SSN/TSN Reset Request Parameter described
in rfc6525 section 4.3.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__packed is considered harmful as it potentially generates code that
doesn't perform well and its usage should be avoided as much as
possible.

This patch drops __packed from all SCTP structures except one, which is
sctp_signed_cookie. In there it's required, as per changelog on
commit 9834a2bb ("[SCTP]: Fix sctp_cookie alignment in the packet.").

After this patch, no alignment changes neither in x86 or x86_64 and
no exceptions were noticed during testing on both archs.

Code size for SCTP module also didn't change with this patch.

Cc: David Miller <davem@davemloft.net>
Cc: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add new transport flag to allow sockets to confirm neighbour.
When same struct dst_entry can be used for many different
neighbours we can not use it for pending confirmations.
The flag is propagated from transport to every packet.
It is reset when cached dst is reset.
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>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to implement sender-side procedures for the Outgoing
and Incoming SSN Reset Request Parameter described in rfc6525 section
5.1.2 and 5.1.3.

It is also add sockopt SCTP_RESET_STREAMS in rfc6525 section 6.3.2
for users.

Note that the new asoc member strreset_outstanding is to make sure
only one reconf request chunk on the fly as rfc6525 section 5.1.1
demands.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add sockopt SCTP_ENABLE_STREAM_RESET to get/set
strreset_enable to indicate which reconf request type it supports,
which is described in rfc6525 section 6.3.1.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add reconf_enable field in all of asoc ep and netns
to indicate if they support stream reset.

When initializing, asoc reconf_enable get the default value from ep
reconf_enable which is from netns netns reconf_enable by default.

It is also to add reconf_capable in asoc peer part to know if peer
supports reconf_enable, the value is set if ext params have reconf
chunk support when processing init chunk, just as rfc6525 section
5.1.1 demands.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add a primitive based on sctp primitive frame for
sending stream reconf request. It works as the other primitives,
and create a SCTP_CMD_REPLY command to send the request chunk out.

sctp_primitive_RECONF would be the api to send a reconf request
chunk.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add a per transport timer based on sctp timer frame
for stream reconf chunk retransmission. It would start after sending
a reconf request chunk, and stop after receiving the response chunk.

If the timer expires, besides retransmitting the reconf request chunk,
it would also do the same thing with data RTO timer. like to increase
the appropriate error counts, and perform threshold management, possibly
destroying the asoc if sctp retransmission thresholds are exceeded, just
as section 5.1.1 describes.

This patch is also to add asoc strreset_chunk, it is used to save the
reconf request chunk, so that it can be retransmitted, and to check if
the response is really for this request by comparing the information
inside with the response chunk as well.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add asoc strreset_outseq and strreset_inseq for
saving the reconf request sequence, initialize them when create
assoc and process init, and also to define Incoming and Outgoing
SSN Reset Request Parameter described in rfc6525 section 4.1 and
4.2, As they can be in one same chunk as section rfc6525 3.1-3
describes, it makes them in one function.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sctp stream reconf, described in RFC 6525, needs a structure to
save per stream information in assoc, like stream state.

In the future, sctp stream scheduler also needs it to save some
stream scheduler params and queues.

This patchset is to prepare the stream array in assoc for stream
reconf. It defines sctp_stream that includes stream arrays inside
to replace ssnmap.

Note that we use different structures for IN and OUT streams, as
the members in per OUT stream will get more and more different
from per IN stream.

v1->v2:
  - put these patches into a smaller group.
v2->v3:
  - define sctp_stream to contain stream arrays, and create stream.c
    to put stream-related functions.
  - merge 3 patches into 1, as new sctp_stream has the same name
    with before.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no reason to use this cascading. It doesn't add anything.
Let's remove it and simplify.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.
Requested-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now sctp transport rhashtable uses hash(lport, dport, daddr) as the key
to hash a node to one chain. If in one host thousands of assocs connect
to one server with the same lport and different laddrs (although it's
not a normal case), all the transports would be hashed into the same
chain.

It may cause to keep returning -EBUSY when inserting a new node, as the
chain is too long and sctp inserts a transport node in a loop, which
could even lead to system hangs there.

The new rhlist interface works for this case that there are many nodes
with the same key in one chain. It puts them into a list then makes this
list be as a node of the chain.

This patch is to replace rhashtable_ interface with rhltable_ interface.
Since a chain would not be too long and it would not return -EBUSY with
this fix when inserting a node, the reinsert loop is also removed here.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prior to this patch, in rx path, before calling lock_sock, it needed to
hold assoc when got it by __sctp_lookup_association, in case other place
would free/put assoc.

But in __sctp_lookup_association, it lookup and hold transport, then got
assoc by transport->assoc, then hold assoc and put transport. It means
it didn't hold transport, yet it was returned and later on directly
assigned to chunk->transport.

Without the protection of sock lock, the transport may be freed/put by
other places, which would cause a use-after-free issue.

This patch is to fix this issue by holding transport instead of assoc.
As holding transport can make sure to access assoc is also safe, and
actually it looks up assoc by searching transport rhashtable, to hold
transport here makes more sense.

Note that the function will be renamed later on on another patch.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The prsctp polices include ttl expires policy already, we should remove
the old ttl expires codes, and just adjust the new polices' codes to be
compatible with the old one for users.

This patch is to remove all the old expires codes, and if prsctp polices
are not set, it will still set msg's expires_at and check the expires in
sctp_check_abandoned.

Note that asoc->prsctp_enable is set by default, so users can't feel any
difference even if they use the old expires api in userspace.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now sctp uses chunk->resent to record if a chunk is retransmitted, for
RTT measurements with retransmitted DATA chunks. chunk->sent_count was
introduced to record how many times one chunk has been sent for prsctp
RTX policy before. We actually can know if one chunk is retransmitted
by checking chunk->sent_count is greater than 1.

This patch is to remove resent from sctp_chunk and reuse sent_count
to avoid retransmitted chunks for RTT measurements.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now sctp uses chunk->prsctp_param to save the prsctp param for all the
prsctp polices, we didn't need to introduce prsctp_param to sctp_chunk.
We can just use chunk->sinfo.sinfo_timetolive for RTX and BUF polices,
and reuse msg->expires_at for TTL policy, as the prsctp polices and old
expires policy are mutual exclusive.

This patch is to remove prsctp_param from sctp_chunk, and reuse msg's
expires_at for TTL and chunk's sinfo.sinfo_timetolive for RTX and BUF
polices.

Note that sctp can't use chunk's sinfo.sinfo_timetolive for TTL policy,
as it needs a u64 variables to save the expires_at time.

This one also fixes the "netperf-Throughput_Mbps -37.2% regression"
issue.

Fixes: a6c2f792 ("sctp: implement prsctp TTL policy")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now pahole sctp_chunk, it has 2 memory holes:
   struct sctp_chunk {
	struct list_head           list;
	atomic_t                   refcnt;
	/* XXX 4 bytes hole, try to pack */
	...
	long unsigned int          prsctp_param;
	int                        sent_count;
	/* XXX 4 bytes hole, try to pack */

This patch is to move up sent_count to fill the 1st one and eliminate
the 2nd one.

It's not just another struct compaction, it also fixes the "netperf-
Throughput_Mbps -37.2% regression" issue when overloading the CPU.

Fixes: a6c2f792 ("sctp: implement prsctp TTL policy")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make it similar to time_before() macros:
- easier to understand
- make use of typecheck() to avoid working on unexpected variable types
  (made the issue on previous patch visible)
- for _[lg]te versions, slighly faster, as the compiler used to generate
  a sequence of cmp/je/cmp/js instructions and now it's sub/test/jle
  (for _lte):

Before, for sctp_outq_sack:
	if (primary->cacc.changeover_active) {
    1f01:	80 b9 84 02 00 00 00 	cmpb   $0x0,0x284(%rcx)
    1f08:	74 6e                	je     1f78 <sctp_outq_sack+0xe8>
		u8 clear_cycling = 0;

		if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
    1f0a:	8b 81 80 02 00 00    	mov    0x280(%rcx),%eax
	return ((s) - (t)) & TSN_SIGN_BIT;
}

static inline int TSN_lte(__u32 s, __u32 t)
{
	return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT);
    1f10:	8b 7d bc             	mov    -0x44(%rbp),%edi
    1f13:	39 c7                	cmp    %eax,%edi
    1f15:	74 25                	je     1f3c <sctp_outq_sack+0xac>
    1f17:	39 f8                	cmp    %edi,%eax
    1f19:	78 21                	js     1f3c <sctp_outq_sack+0xac>
			primary->cacc.changeover_active = 0;

After:
	if (primary->cacc.changeover_active) {
    1ee7:	80 b9 84 02 00 00 00 	cmpb   $0x0,0x284(%rcx)
    1eee:	74 73                	je     1f63 <sctp_outq_sack+0xf3>
		u8 clear_cycling = 0;

		if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
    1ef0:	8b 81 80 02 00 00    	mov    0x280(%rcx),%eax
    1ef6:	2b 45 b4             	sub    -0x4c(%rbp),%eax
    1ef9:	85 c0                	test   %eax,%eax
    1efb:	7e 26                	jle    1f23 <sctp_outq_sack+0xb3>
			primary->cacc.changeover_active = 0;

*_lt() generated pretty much the same code.
Tested with gcc (GCC) 6.1.1 20160621.

This patch also removes SSN_lte as it is not used and cleanups some
comments.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To something more meaningful these days, specially because this is
working on packet headers or lengths and which are not tied to any CPU
arch but to the protocol itself.

So, WORD_TRUNC becomes SCTP_TRUNC4 and WORD_ROUND becomes SCTP_PAD4.
Reported-by: NDavid Laight <David.Laight@ACULAB.COM>
Reported-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sctp_outq_flush return value is meaningless now, this patch is
to make sctp_outq_flush return void, as well as sctp_outq_fail
and sctp_outq_uncork.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Last patch "sctp: do not return the transmit err back to sctp_sendmsg"
made sctp_primitive_SEND return err only when asoc state is unavailable.
In this case, chunks are not enqueued, they have no chance to be freed if
we don't take care of them later.

This Patch is actually to revert commit 1cd4d5c4 ("sctp: remove the
unused sctp_datamsg_free()"), commit 69b5777f ("sctp: hold the chunks
only after the chunk is enqueued in outq") and commit 8b570dc9 ("sctp:
only drop the reference on the datamsg after sending a msg"), to use
sctp_datamsg_free to free the chunks of current msg.

Fixes: 8b570dc9 ("sctp: only drop the reference on the datamsg after sending a msg")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This function actually operates on u32 yet its paramteres were declared
as u16, causing integer truncation upon calling.

Note in patch context that ADDIP_SERIAL_SIGN_BIT is already 32 bits.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prior to this patch, sctp defined TCP_CLOSING as SCTP_SS_CLOSING.
TCP_CLOSING is such a special sk state in TCP that inet common codes
even exclude it.

For instance, inet_accept thinks the accept sk's state never be
TCP_CLOSING, or it will give a WARN_ON. TCP works well with that
while SCTP may trigger the call trace, as CLOSING state in SCTP
has different meaning from TCP.

This fix is to change to use TCP_CLOSE_WAIT as SCTP_SS_CLOSING,
instead of TCP_CLOSING. Some side-effects could be expected,
regardless of not being used before. inet_accept will accept it
now.

I did all the func_tests in lksctp-tools and ran sctp codnomicon
fuzzer tests against this patch, no regression or failure found.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Identifying address family operations during rx path is not something
expensive but it's ugly to the eye to have it done multiple times,
specially when we already validated it during initial rx processing.

This patch takes advantage of the now shared sctp_input_cb and make the
pointer to the operations readily available.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SCTP will try to access original IP headers on sctp_recvmsg in order to
copy the addresses used. There are also other places that do similar access
to IP or even SCTP headers. But after 90017acc ("sctp: Add GSO
support") they aren't always there because they are only present in the
header skb.

SCTP handles the queueing of incoming data by cloning the incoming skb
and limiting to only the relevant payload. This clone has its cb updated
to something different and it's then queued on socket rx queue. Thus we
need to fix this in two moments.

For rx path, not related to socket queue yet, this patch uses a
partially copied sctp_input_cb to such GSO frags. This restores the
ability to access the headers for this part of the code.

Regarding the socket rx queue, it removes iif member from sctp_event and
also add a chunk pointer on it.

With these changes we're always able to reach the headers again.

The biggest change here is that now the sctp_chunk struct and the
original skb are only freed after the application consumed the buffer.
Note however that the original payload was already like this due to the
skb cloning.

For iif, SCTP's IPv4 code doesn't use it, so no change is necessary.
IPv6 now can fetch it directly from original's IPv6 CB as the original
skb is still accessible.

In the future we probably can simplify sctp_v*_skb_iif() stuff, as
sctp_v4_skb_iif() was called but it's return value not used, and now
it's not even called, but such cleanup is out of scope for this change.

Fixes: 90017acc ("sctp: Add GSO support")
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The next patch needs 8 bytes in there. sctp_ulpevent has a hole due to
bad alignment; msg_flags is using 4 bytes while it actually uses only 2, so
we shrink it, and iif member (4 bytes) which can be easily fetched from
another place once the next patch is there, so we remove it and thus
creating space for 8 bytes.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We process input path in other files too and having access to it is
nice, so move it to a header where it's shared.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>