linux-stable/include/net/sctp/sctp.h
Xin Long 819be8108f sctp: add chunks to sk_backlog when the newsk sk_socket is not set
This patch is to fix a NULL-ptr deref in selinux_socket_connect_helper:

  [...] kasan: GPF could be caused by NULL-ptr deref or user memory access
  [...] RIP: 0010:selinux_socket_connect_helper+0x94/0x460
  [...] Call Trace:
  [...]  selinux_sctp_bind_connect+0x16a/0x1d0
  [...]  security_sctp_bind_connect+0x58/0x90
  [...]  sctp_process_asconf+0xa52/0xfd0 [sctp]
  [...]  sctp_sf_do_asconf+0x785/0x980 [sctp]
  [...]  sctp_do_sm+0x175/0x5a0 [sctp]
  [...]  sctp_assoc_bh_rcv+0x285/0x5b0 [sctp]
  [...]  sctp_backlog_rcv+0x482/0x910 [sctp]
  [...]  __release_sock+0x11e/0x310
  [...]  release_sock+0x4f/0x180
  [...]  sctp_accept+0x3f9/0x5a0 [sctp]
  [...]  inet_accept+0xe7/0x720

It was caused by that the 'newsk' sk_socket was not set before going to
security sctp hook when processing asconf chunk with SCTP_PARAM_ADD_IP
or SCTP_PARAM_SET_PRIMARY:

  inet_accept()->
    sctp_accept():
      lock_sock():
          lock listening 'sk'
                                          do_softirq():
                                            sctp_rcv():  <-- [1]
                                                asconf chunk arrives and
                                                enqueued in 'sk' backlog
      sctp_sock_migrate():
          set asoc's sk to 'newsk'
      release_sock():
          sctp_backlog_rcv():
            lock 'newsk'
            sctp_process_asconf()  <-- [2]
            unlock 'newsk'
    sock_graft():
        set sk_socket  <-- [3]

As it shows, at [1] the asconf chunk would be put into the listening 'sk'
backlog, as accept() was holding its sock lock. Then at [2] asconf would
get processed with 'newsk' as asoc's sk had been set to 'newsk'. However,
'newsk' sk_socket is not set until [3], while selinux_sctp_bind_connect()
would deref it, then kernel crashed.

Here to fix it by adding the chunk to sk_backlog until newsk sk_socket is
set when .accept() is done.

Note that sk->sk_socket can be NULL when the sock is closed, so SOCK_DEAD
flag is also needed to check in sctp_newsk_ready().

Thanks to Ondrej for reviewing the code.

Fixes: d452930fd3 ("selinux: Add SCTP support")
Reported-by: Ying Xu <yinxu@redhat.com>
Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-09 16:27:04 -07:00

618 lines
19 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001-2003 Intel Corp.
*
* This file is part of the SCTP kernel implementation
*
* The base lksctp header.
*
* 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:
* La Monte H.P. Yarroll <piggy@acm.org>
* Xingang Guo <xingang.guo@intel.com>
* Jon Grimm <jgrimm@us.ibm.com>
* Daisy Chang <daisyc@us.ibm.com>
* Sridhar Samudrala <sri@us.ibm.com>
* Ardelle Fan <ardelle.fan@intel.com>
* Ryan Layer <rmlayer@us.ibm.com>
* Kevin Gao <kevin.gao@intel.com>
*/
#ifndef __net_sctp_h__
#define __net_sctp_h__
/* Header Strategy.
* Start getting some control over the header file depencies:
* includes
* constants
* structs
* prototypes
* macros, externs, and inlines
*
* Move test_frame specific items out of the kernel headers
* and into the test frame headers. This is not perfect in any sense
* and will continue to evolve.
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <linux/tty.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/idr.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/ip6_route.h>
#endif
#include <linux/uaccess.h>
#include <asm/page.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/sctp/structs.h>
#include <net/sctp/constants.h>
#ifdef CONFIG_IP_SCTP_MODULE
#define SCTP_PROTOSW_FLAG 0
#else /* static! */
#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
#endif
/* Round an int up to the next multiple of 4. */
#define SCTP_PAD4(s) (((s)+3)&~3)
/* Truncate to the previous multiple of 4. */
#define SCTP_TRUNC4(s) ((s)&~3)
/*
* Function declarations.
*/
/*
* sctp/protocol.c
*/
int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *addr,
enum sctp_scope, gfp_t gfp, int flags);
struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
int sctp_register_pf(struct sctp_pf *, sa_family_t);
void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
/*
* sctp/socket.c
*/
int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags);
int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
int sctp_inet_listen(struct socket *sock, int backlog);
void sctp_write_space(struct sock *sk);
void sctp_data_ready(struct sock *sk);
__poll_t sctp_poll(struct file *file, struct socket *sock,
poll_table *wait);
void sctp_sock_rfree(struct sk_buff *skb);
void sctp_copy_sock(struct sock *newsk, struct sock *sk,
struct sctp_association *asoc);
extern struct percpu_counter sctp_sockets_allocated;
int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
void sctp_transport_walk_start(struct rhashtable_iter *iter);
void sctp_transport_walk_stop(struct rhashtable_iter *iter);
struct sctp_transport *sctp_transport_get_next(struct net *net,
struct rhashtable_iter *iter);
struct sctp_transport *sctp_transport_get_idx(struct net *net,
struct rhashtable_iter *iter, int pos);
int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
struct net *net,
const union sctp_addr *laddr,
const union sctp_addr *paddr, void *p);
int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
int (*cb_done)(struct sctp_transport *, void *),
struct net *net, int *pos, void *p);
int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p);
int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
struct sctp_info *info);
/*
* sctp/primitive.c
*/
int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
void *arg);
/*
* sctp/input.c
*/
int sctp_rcv(struct sk_buff *skb);
int sctp_v4_err(struct sk_buff *skb, u32 info);
int sctp_hash_endpoint(struct sctp_endpoint *ep);
void sctp_unhash_endpoint(struct sctp_endpoint *);
struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
struct sctphdr *, struct sctp_association **,
struct sctp_transport **);
void sctp_err_finish(struct sock *, struct sctp_transport *);
void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
struct sctp_transport *t, __u32 pmtu);
void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
struct sk_buff *);
void sctp_icmp_proto_unreachable(struct sock *sk,
struct sctp_association *asoc,
struct sctp_transport *t);
void sctp_backlog_migrate(struct sctp_association *assoc,
struct sock *oldsk, struct sock *newsk);
int sctp_transport_hashtable_init(void);
void sctp_transport_hashtable_destroy(void);
int sctp_hash_transport(struct sctp_transport *t);
void sctp_unhash_transport(struct sctp_transport *t);
struct sctp_transport *sctp_addrs_lookup_transport(
struct net *net,
const union sctp_addr *laddr,
const union sctp_addr *paddr);
struct sctp_transport *sctp_epaddr_lookup_transport(
const struct sctp_endpoint *ep,
const union sctp_addr *paddr);
/*
* sctp/proc.c
*/
int __net_init sctp_proc_init(struct net *net);
/*
* sctp/offload.c
*/
int sctp_offload_init(void);
/*
* sctp/stream_sched.c
*/
void sctp_sched_ops_init(void);
/*
* sctp/stream.c
*/
int sctp_send_reset_streams(struct sctp_association *asoc,
struct sctp_reset_streams *params);
int sctp_send_reset_assoc(struct sctp_association *asoc);
int sctp_send_add_streams(struct sctp_association *asoc,
struct sctp_add_streams *params);
/*
* Module global variables
*/
/*
* sctp/protocol.c
*/
extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
extern long sysctl_sctp_mem[3];
extern int sysctl_sctp_rmem[3];
extern int sysctl_sctp_wmem[3];
/*
* Section: Macros, externs, and inlines
*/
/* SCTP SNMP MIB stats handlers */
#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
#define __SCTP_INC_STATS(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
/* sctp mib definitions */
enum {
SCTP_MIB_NUM = 0,
SCTP_MIB_CURRESTAB, /* CurrEstab */
SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */
SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */
SCTP_MIB_ABORTEDS, /* Aborteds */
SCTP_MIB_SHUTDOWNS, /* Shutdowns */
SCTP_MIB_OUTOFBLUES, /* OutOfBlues */
SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */
SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */
SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */
SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */
SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */
SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */
SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */
SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */
SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */
SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */
SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */
SCTP_MIB_T1_INIT_EXPIREDS,
SCTP_MIB_T1_COOKIE_EXPIREDS,
SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
SCTP_MIB_T3_RTX_EXPIREDS,
SCTP_MIB_T4_RTO_EXPIREDS,
SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
SCTP_MIB_DELAY_SACK_EXPIREDS,
SCTP_MIB_AUTOCLOSE_EXPIREDS,
SCTP_MIB_T1_RETRANSMITS,
SCTP_MIB_T3_RETRANSMITS,
SCTP_MIB_PMTUD_RETRANSMITS,
SCTP_MIB_FAST_RETRANSMITS,
SCTP_MIB_IN_PKT_SOFTIRQ,
SCTP_MIB_IN_PKT_BACKLOG,
SCTP_MIB_IN_PKT_DISCARDS,
SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
__SCTP_MIB_MAX
};
#define SCTP_MIB_MAX __SCTP_MIB_MAX
struct sctp_mib {
unsigned long mibs[SCTP_MIB_MAX];
};
/* helper function to track stats about max rto and related transport */
static inline void sctp_max_rto(struct sctp_association *asoc,
struct sctp_transport *trans)
{
if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
asoc->stats.max_obs_rto = trans->rto;
memset(&asoc->stats.obs_rto_ipaddr, 0,
sizeof(struct sockaddr_storage));
memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
trans->af_specific->sockaddr_len);
}
}
/*
* Macros for keeping a global reference of object allocations.
*/
#ifdef CONFIG_SCTP_DBG_OBJCNT
extern atomic_t sctp_dbg_objcnt_sock;
extern atomic_t sctp_dbg_objcnt_ep;
extern atomic_t sctp_dbg_objcnt_assoc;
extern atomic_t sctp_dbg_objcnt_transport;
extern atomic_t sctp_dbg_objcnt_chunk;
extern atomic_t sctp_dbg_objcnt_bind_addr;
extern atomic_t sctp_dbg_objcnt_bind_bucket;
extern atomic_t sctp_dbg_objcnt_addr;
extern atomic_t sctp_dbg_objcnt_datamsg;
extern atomic_t sctp_dbg_objcnt_keys;
/* Macros to atomically increment/decrement objcnt counters. */
#define SCTP_DBG_OBJCNT_INC(name) \
atomic_inc(&sctp_dbg_objcnt_## name)
#define SCTP_DBG_OBJCNT_DEC(name) \
atomic_dec(&sctp_dbg_objcnt_## name)
#define SCTP_DBG_OBJCNT(name) \
atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
/* Macro to help create new entries in in the global array of
* objcnt counters.
*/
#define SCTP_DBG_OBJCNT_ENTRY(name) \
{.label= #name, .counter= &sctp_dbg_objcnt_## name}
void sctp_dbg_objcnt_init(struct net *);
#else
#define SCTP_DBG_OBJCNT_INC(name)
#define SCTP_DBG_OBJCNT_DEC(name)
static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
#if defined CONFIG_SYSCTL
void sctp_sysctl_register(void);
void sctp_sysctl_unregister(void);
int sctp_sysctl_net_register(struct net *net);
void sctp_sysctl_net_unregister(struct net *net);
#else
static inline void sctp_sysctl_register(void) { return; }
static inline void sctp_sysctl_unregister(void) { return; }
static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
#endif
/* Size of Supported Address Parameter for 'x' address types. */
#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
#if IS_ENABLED(CONFIG_IPV6)
void sctp_v6_pf_init(void);
void sctp_v6_pf_exit(void);
int sctp_v6_protosw_init(void);
void sctp_v6_protosw_exit(void);
int sctp_v6_add_protocol(void);
void sctp_v6_del_protocol(void);
#else /* #ifdef defined(CONFIG_IPV6) */
static inline void sctp_v6_pf_init(void) { return; }
static inline void sctp_v6_pf_exit(void) { return; }
static inline int sctp_v6_protosw_init(void) { return 0; }
static inline void sctp_v6_protosw_exit(void) { return; }
static inline int sctp_v6_add_protocol(void) { return 0; }
static inline void sctp_v6_del_protocol(void) { return; }
#endif /* #if defined(CONFIG_IPV6) */
/* Map an association to an assoc_id. */
static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
{
return asoc ? asoc->assoc_id : 0;
}
static inline enum sctp_sstat_state
sctp_assoc_to_state(const struct sctp_association *asoc)
{
/* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
* got rid of it in kernel space. Therefore SCTP_CLOSED et al
* start at =1 in user space, but actually as =0 in kernel space.
* Now that we can not break user space and SCTP_EMPTY is exposed
* there, we need to fix it up with an ugly offset not to break
* applications. :(
*/
return asoc->state + 1;
}
/* Look up the association by its id. */
struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
/* A macro to walk a list of skbs. */
#define sctp_skb_for_each(pos, head, tmp) \
skb_queue_walk_safe(head, pos, tmp)
/**
* sctp_list_dequeue - remove from the head of the queue
* @list: list to dequeue from
*
* Remove the head of the list. The head item is
* returned or %NULL if the list is empty.
*/
static inline struct list_head *sctp_list_dequeue(struct list_head *list)
{
struct list_head *result = NULL;
if (!list_empty(list)) {
result = list->next;
list_del_init(result);
}
return result;
}
/* SCTP version of skb_set_owner_r. We need this one because
* of the way we have to do receive buffer accounting on bundled
* chunks.
*/
static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
{
struct sctp_ulpevent *event = sctp_skb2event(skb);
skb_orphan(skb);
skb->sk = sk;
skb->destructor = sctp_sock_rfree;
atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
/*
* This mimics the behavior of skb_set_owner_r
*/
sk_mem_charge(sk, event->rmem_len);
}
/* Tests if the list has one and only one entry. */
static inline int sctp_list_single_entry(struct list_head *head)
{
return (head->next != head) && (head->next == head->prev);
}
static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
{
return !list_empty(&chunk->list);
}
/* Walk through a list of TLV parameters. Don't trust the
* individual parameter lengths and instead depend on
* the chunk length to indicate when to stop. Make sure
* there is room for a param header too.
*/
#define sctp_walk_params(pos, chunk, member)\
_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
#define _sctp_walk_params(pos, chunk, end, member)\
for (pos.v = chunk->member;\
(pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
(void *)chunk + end) &&\
pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
pos.v += SCTP_PAD4(ntohs(pos.p->length)))
#define sctp_walk_errors(err, chunk_hdr)\
_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
#define _sctp_walk_errors(err, chunk_hdr, end)\
for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
sizeof(struct sctp_chunkhdr));\
((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
(void *)chunk_hdr + end) &&\
(void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
ntohs(err->length) >= sizeof(struct sctp_errhdr); \
err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
#define sctp_walk_fwdtsn(pos, chunk)\
_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
#define _sctp_walk_fwdtsn(pos, chunk, end)\
for (pos = chunk->subh.fwdtsn_hdr->skip;\
(void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
pos++)
/* External references. */
extern struct proto sctp_prot;
extern struct proto sctpv6_prot;
void sctp_put_port(struct sock *sk);
extern struct idr sctp_assocs_id;
extern spinlock_t sctp_assocs_id_lock;
/* Static inline functions. */
/* Convert from an IP version number to an Address Family symbol. */
static inline int ipver2af(__u8 ipver)
{
switch (ipver) {
case 4:
return AF_INET;
case 6:
return AF_INET6;
default:
return 0;
}
}
/* Convert from an address parameter type to an address family. */
static inline int param_type2af(__be16 type)
{
switch (type) {
case SCTP_PARAM_IPV4_ADDRESS:
return AF_INET;
case SCTP_PARAM_IPV6_ADDRESS:
return AF_INET6;
default:
return 0;
}
}
/* Warning: The following hash functions assume a power of two 'size'. */
/* This is the hash function for the SCTP port hash table. */
static inline int sctp_phashfn(struct net *net, __u16 lport)
{
return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
}
/* This is the hash function for the endpoint hash table. */
static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
{
return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
}
#define sctp_for_each_hentry(epb, head) \
hlist_for_each_entry(epb, head, node)
/* Is a socket of this style? */
#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
static inline int __sctp_style(const struct sock *sk,
enum sctp_socket_type style)
{
return sctp_sk(sk)->type == style;
}
/* Is the association in this state? */
#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
static inline int __sctp_state(const struct sctp_association *asoc,
enum sctp_state state)
{
return asoc->state == state;
}
/* Is the socket in this state? */
#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
static inline int __sctp_sstate(const struct sock *sk,
enum sctp_sock_state state)
{
return sk->sk_state == state;
}
/* Map v4-mapped v6 address back to v4 address */
static inline void sctp_v6_map_v4(union sctp_addr *addr)
{
addr->v4.sin_family = AF_INET;
addr->v4.sin_port = addr->v6.sin6_port;
addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
}
/* Map v4 address to v4-mapped v6 address */
static inline void sctp_v4_map_v6(union sctp_addr *addr)
{
__be16 port;
port = addr->v4.sin_port;
addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
addr->v6.sin6_port = port;
addr->v6.sin6_family = AF_INET6;
addr->v6.sin6_flowinfo = 0;
addr->v6.sin6_scope_id = 0;
addr->v6.sin6_addr.s6_addr32[0] = 0;
addr->v6.sin6_addr.s6_addr32[1] = 0;
addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
}
/* The cookie is always 0 since this is how it's used in the
* pmtu code.
*/
static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
{
if (t->dst && !dst_check(t->dst, t->dst_cookie))
sctp_transport_dst_release(t);
return t->dst;
}
/* Calculate max payload size given a MTU, or the total overhead if
* given MTU is zero
*/
static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
__u32 mtu, __u32 extra)
{
__u32 overhead = sizeof(struct sctphdr) + extra;
if (sp)
overhead += sp->pf->af->net_header_len;
else
overhead += sizeof(struct ipv6hdr);
if (WARN_ON_ONCE(mtu && mtu <= overhead))
mtu = overhead;
return mtu ? mtu - overhead : overhead;
}
static inline __u32 sctp_dst_mtu(const struct dst_entry *dst)
{
return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst),
SCTP_DEFAULT_MINSEGMENT));
}
static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
{
__u32 pmtu = sctp_dst_mtu(t->dst);
if (t->pathmtu == pmtu)
return true;
t->pathmtu = pmtu;
return false;
}
static inline __u32 sctp_min_frag_point(struct sctp_sock *sp, __u16 datasize)
{
return sctp_mtu_payload(sp, SCTP_DEFAULT_MINSEGMENT, datasize);
}
static inline bool sctp_newsk_ready(const struct sock *sk)
{
return sock_flag(sk, SOCK_DEAD) || sk->sk_socket;
}
#endif /* __net_sctp_h__ */