remarkable-linux/include/net/sctp/ulpevent.h
Marcelo Ricardo Leitner 1f45f78f8e sctp: allow GSO frags to access the chunk too
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 90017accff ("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: 90017accff ("sctp: Add GSO support")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-13 18:10:14 -07:00

163 lines
4.9 KiB
C

/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001 Intel Corp.
* Copyright (c) 2001 Nokia, Inc.
* Copyright (c) 2001 La Monte H.P. Yarroll
*
* These are the definitions needed for the sctp_ulpevent type. The
* sctp_ulpevent type is used to carry information from the state machine
* upwards to the ULP.
*
* This file is part of the SCTP kernel implementation
*
* This SCTP implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* Written or modified by:
* Jon Grimm <jgrimm@us.ibm.com>
* La Monte H.P. Yarroll <piggy@acm.org>
* Karl Knutson <karl@athena.chicago.il.us>
* Sridhar Samudrala <sri@us.ibm.com>
*/
#ifndef __sctp_ulpevent_h__
#define __sctp_ulpevent_h__
/* A structure to carry information to the ULP (e.g. Sockets API) */
/* Warning: This sits inside an skb.cb[] area. Be very careful of
* growing this structure as it is at the maximum limit now.
*/
struct sctp_ulpevent {
struct sctp_association *asoc;
struct sctp_chunk *chunk;
unsigned int rmem_len;
__u32 ppid;
__u32 tsn;
__u32 cumtsn;
__u16 stream;
__u16 ssn;
__u16 flags;
__u16 msg_flags;
};
/* Retrieve the skb this event sits inside of. */
static inline struct sk_buff *sctp_event2skb(const struct sctp_ulpevent *ev)
{
return container_of((void *)ev, struct sk_buff, cb);
}
/* Retrieve & cast the event sitting inside the skb. */
static inline struct sctp_ulpevent *sctp_skb2event(struct sk_buff *skb)
{
return (struct sctp_ulpevent *)skb->cb;
}
void sctp_ulpevent_free(struct sctp_ulpevent *);
int sctp_ulpevent_is_notification(const struct sctp_ulpevent *);
unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list);
struct sctp_ulpevent *sctp_ulpevent_make_assoc_change(
const struct sctp_association *asoc,
__u16 flags,
__u16 state,
__u16 error,
__u16 outbound,
__u16 inbound,
struct sctp_chunk *chunk,
gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
const struct sctp_association *asoc,
const struct sockaddr_storage *aaddr,
int flags,
int state,
int error,
gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_remote_error(
const struct sctp_association *asoc,
struct sctp_chunk *chunk,
__u16 flags,
gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
const struct sctp_association *asoc,
struct sctp_chunk *chunk,
__u16 flags,
__u32 error,
gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
const struct sctp_association *asoc,
__u16 flags,
gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
const struct sctp_association *asoc,
__u32 indication, gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
const struct sctp_association *asoc, gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
struct sctp_chunk *chunk,
gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_authkey(
const struct sctp_association *asoc, __u16 key_id,
__u32 indication, gfp_t gfp);
struct sctp_ulpevent *sctp_ulpevent_make_sender_dry_event(
const struct sctp_association *asoc, gfp_t gfp);
void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
struct msghdr *);
void sctp_ulpevent_read_rcvinfo(const struct sctp_ulpevent *event,
struct msghdr *);
void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
struct msghdr *, struct sock *sk);
__u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event);
/* Is this event type enabled? */
static inline int sctp_ulpevent_type_enabled(__u16 sn_type,
struct sctp_event_subscribe *mask)
{
char *amask = (char *) mask;
return amask[sn_type - SCTP_SN_TYPE_BASE];
}
/* Given an event subscription, is this event enabled? */
static inline int sctp_ulpevent_is_enabled(const struct sctp_ulpevent *event,
struct sctp_event_subscribe *mask)
{
__u16 sn_type;
int enabled = 1;
if (sctp_ulpevent_is_notification(event)) {
sn_type = sctp_ulpevent_get_notification_type(event);
enabled = sctp_ulpevent_type_enabled(sn_type, mask);
}
return enabled;
}
#endif /* __sctp_ulpevent_h__ */