1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2003 Intel Corp.
7 * This file is part of the SCTP kernel implementation
9 * The base lksctp header.
11 * This SCTP implementation is free software;
12 * you can redistribute it and/or modify it under the terms of
13 * the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
17 * This SCTP implementation is distributed in the hope that it
18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with GNU CC; see the file COPYING. If not, see
25 * <http://www.gnu.org/licenses/>.
27 * Please send any bug reports or fixes you make to the
29 * lksctp developers <linux-sctp@vger.kernel.org>
31 * Written or modified by:
32 * La Monte H.P. Yarroll <piggy@acm.org>
33 * Xingang Guo <xingang.guo@intel.com>
34 * Jon Grimm <jgrimm@us.ibm.com>
35 * Daisy Chang <daisyc@us.ibm.com>
36 * Sridhar Samudrala <sri@us.ibm.com>
37 * Ardelle Fan <ardelle.fan@intel.com>
38 * Ryan Layer <rmlayer@us.ibm.com>
39 * Kevin Gao <kevin.gao@intel.com>
42 #ifndef __net_sctp_h__
43 #define __net_sctp_h__
46 * Start getting some control over the header file depencies:
51 * macros, externs, and inlines
53 * Move test_frame specific items out of the kernel headers
54 * and into the test frame headers. This is not perfect in any sense
55 * and will continue to evolve.
58 #include <linux/types.h>
59 #include <linux/slab.h>
61 #include <linux/tty.h>
62 #include <linux/proc_fs.h>
63 #include <linux/spinlock.h>
64 #include <linux/jiffies.h>
65 #include <linux/idr.h>
67 #if IS_ENABLED(CONFIG_IPV6)
69 #include <net/ip6_route.h>
72 #include <linux/uaccess.h>
76 #include <net/sctp/structs.h>
77 #include <net/sctp/constants.h>
79 #ifdef CONFIG_IP_SCTP_MODULE
80 #define SCTP_PROTOSW_FLAG 0
82 #define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
85 /* Round an int up to the next multiple of 4. */
86 #define SCTP_PAD4(s) (((s)+3)&~3)
87 /* Truncate to the previous multiple of 4. */
88 #define SCTP_TRUNC4(s) ((s)&~3)
91 * Function declarations.
97 int sctp_copy_local_addr_list(struct net
*net
, struct sctp_bind_addr
*addr
,
98 enum sctp_scope
, gfp_t gfp
, int flags
);
99 struct sctp_pf
*sctp_get_pf_specific(sa_family_t family
);
100 int sctp_register_pf(struct sctp_pf
*, sa_family_t
);
101 void sctp_addr_wq_mgmt(struct net
*, struct sctp_sockaddr_entry
*, int);
106 int sctp_inet_connect(struct socket
*sock
, struct sockaddr
*uaddr
,
107 int addr_len
, int flags
);
108 int sctp_backlog_rcv(struct sock
*sk
, struct sk_buff
*skb
);
109 int sctp_inet_listen(struct socket
*sock
, int backlog
);
110 void sctp_write_space(struct sock
*sk
);
111 void sctp_data_ready(struct sock
*sk
);
112 __poll_t
sctp_poll(struct file
*file
, struct socket
*sock
,
114 void sctp_sock_rfree(struct sk_buff
*skb
);
115 void sctp_copy_sock(struct sock
*newsk
, struct sock
*sk
,
116 struct sctp_association
*asoc
);
117 extern struct percpu_counter sctp_sockets_allocated
;
118 int sctp_asconf_mgmt(struct sctp_sock
*, struct sctp_sockaddr_entry
*);
119 struct sk_buff
*sctp_skb_recv_datagram(struct sock
*, int, int, int *);
121 void sctp_transport_walk_start(struct rhashtable_iter
*iter
);
122 void sctp_transport_walk_stop(struct rhashtable_iter
*iter
);
123 struct sctp_transport
*sctp_transport_get_next(struct net
*net
,
124 struct rhashtable_iter
*iter
);
125 struct sctp_transport
*sctp_transport_get_idx(struct net
*net
,
126 struct rhashtable_iter
*iter
, int pos
);
127 int sctp_transport_lookup_process(int (*cb
)(struct sctp_transport
*, void *),
129 const union sctp_addr
*laddr
,
130 const union sctp_addr
*paddr
, void *p
);
131 int sctp_for_each_transport(int (*cb
)(struct sctp_transport
*, void *),
132 int (*cb_done
)(struct sctp_transport
*, void *),
133 struct net
*net
, int *pos
, void *p
);
134 int sctp_for_each_endpoint(int (*cb
)(struct sctp_endpoint
*, void *), void *p
);
135 int sctp_get_sctp_info(struct sock
*sk
, struct sctp_association
*asoc
,
136 struct sctp_info
*info
);
141 int sctp_primitive_ASSOCIATE(struct net
*, struct sctp_association
*, void *arg
);
142 int sctp_primitive_SHUTDOWN(struct net
*, struct sctp_association
*, void *arg
);
143 int sctp_primitive_ABORT(struct net
*, struct sctp_association
*, void *arg
);
144 int sctp_primitive_SEND(struct net
*, struct sctp_association
*, void *arg
);
145 int sctp_primitive_REQUESTHEARTBEAT(struct net
*, struct sctp_association
*, void *arg
);
146 int sctp_primitive_ASCONF(struct net
*, struct sctp_association
*, void *arg
);
147 int sctp_primitive_RECONF(struct net
*net
, struct sctp_association
*asoc
,
153 int sctp_rcv(struct sk_buff
*skb
);
154 int sctp_v4_err(struct sk_buff
*skb
, u32 info
);
155 int sctp_hash_endpoint(struct sctp_endpoint
*ep
);
156 void sctp_unhash_endpoint(struct sctp_endpoint
*);
157 struct sock
*sctp_err_lookup(struct net
*net
, int family
, struct sk_buff
*,
158 struct sctphdr
*, struct sctp_association
**,
159 struct sctp_transport
**);
160 void sctp_err_finish(struct sock
*, struct sctp_transport
*);
161 void sctp_icmp_frag_needed(struct sock
*, struct sctp_association
*,
162 struct sctp_transport
*t
, __u32 pmtu
);
163 void sctp_icmp_redirect(struct sock
*, struct sctp_transport
*,
165 void sctp_icmp_proto_unreachable(struct sock
*sk
,
166 struct sctp_association
*asoc
,
167 struct sctp_transport
*t
);
168 void sctp_backlog_migrate(struct sctp_association
*assoc
,
169 struct sock
*oldsk
, struct sock
*newsk
);
170 int sctp_transport_hashtable_init(void);
171 void sctp_transport_hashtable_destroy(void);
172 int sctp_hash_transport(struct sctp_transport
*t
);
173 void sctp_unhash_transport(struct sctp_transport
*t
);
174 struct sctp_transport
*sctp_addrs_lookup_transport(
176 const union sctp_addr
*laddr
,
177 const union sctp_addr
*paddr
);
178 struct sctp_transport
*sctp_epaddr_lookup_transport(
179 const struct sctp_endpoint
*ep
,
180 const union sctp_addr
*paddr
);
185 int __net_init
sctp_proc_init(struct net
*net
);
190 int sctp_offload_init(void);
193 * sctp/stream_sched.c
195 void sctp_sched_ops_init(void);
200 int sctp_send_reset_streams(struct sctp_association
*asoc
,
201 struct sctp_reset_streams
*params
);
202 int sctp_send_reset_assoc(struct sctp_association
*asoc
);
203 int sctp_send_add_streams(struct sctp_association
*asoc
,
204 struct sctp_add_streams
*params
);
207 * Module global variables
213 extern struct kmem_cache
*sctp_chunk_cachep __read_mostly
;
214 extern struct kmem_cache
*sctp_bucket_cachep __read_mostly
;
215 extern long sysctl_sctp_mem
[3];
216 extern int sysctl_sctp_rmem
[3];
217 extern int sysctl_sctp_wmem
[3];
220 * Section: Macros, externs, and inlines
223 /* SCTP SNMP MIB stats handlers */
224 #define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
225 #define __SCTP_INC_STATS(net, field) __SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
226 #define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
228 /* sctp mib definitions */
231 SCTP_MIB_CURRESTAB
, /* CurrEstab */
232 SCTP_MIB_ACTIVEESTABS
, /* ActiveEstabs */
233 SCTP_MIB_PASSIVEESTABS
, /* PassiveEstabs */
234 SCTP_MIB_ABORTEDS
, /* Aborteds */
235 SCTP_MIB_SHUTDOWNS
, /* Shutdowns */
236 SCTP_MIB_OUTOFBLUES
, /* OutOfBlues */
237 SCTP_MIB_CHECKSUMERRORS
, /* ChecksumErrors */
238 SCTP_MIB_OUTCTRLCHUNKS
, /* OutCtrlChunks */
239 SCTP_MIB_OUTORDERCHUNKS
, /* OutOrderChunks */
240 SCTP_MIB_OUTUNORDERCHUNKS
, /* OutUnorderChunks */
241 SCTP_MIB_INCTRLCHUNKS
, /* InCtrlChunks */
242 SCTP_MIB_INORDERCHUNKS
, /* InOrderChunks */
243 SCTP_MIB_INUNORDERCHUNKS
, /* InUnorderChunks */
244 SCTP_MIB_FRAGUSRMSGS
, /* FragUsrMsgs */
245 SCTP_MIB_REASMUSRMSGS
, /* ReasmUsrMsgs */
246 SCTP_MIB_OUTSCTPPACKS
, /* OutSCTPPacks */
247 SCTP_MIB_INSCTPPACKS
, /* InSCTPPacks */
248 SCTP_MIB_T1_INIT_EXPIREDS
,
249 SCTP_MIB_T1_COOKIE_EXPIREDS
,
250 SCTP_MIB_T2_SHUTDOWN_EXPIREDS
,
251 SCTP_MIB_T3_RTX_EXPIREDS
,
252 SCTP_MIB_T4_RTO_EXPIREDS
,
253 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
,
254 SCTP_MIB_DELAY_SACK_EXPIREDS
,
255 SCTP_MIB_AUTOCLOSE_EXPIREDS
,
256 SCTP_MIB_T1_RETRANSMITS
,
257 SCTP_MIB_T3_RETRANSMITS
,
258 SCTP_MIB_PMTUD_RETRANSMITS
,
259 SCTP_MIB_FAST_RETRANSMITS
,
260 SCTP_MIB_IN_PKT_SOFTIRQ
,
261 SCTP_MIB_IN_PKT_BACKLOG
,
262 SCTP_MIB_IN_PKT_DISCARDS
,
263 SCTP_MIB_IN_DATA_CHUNK_DISCARDS
,
267 #define SCTP_MIB_MAX __SCTP_MIB_MAX
269 unsigned long mibs
[SCTP_MIB_MAX
];
272 /* helper function to track stats about max rto and related transport */
273 static inline void sctp_max_rto(struct sctp_association
*asoc
,
274 struct sctp_transport
*trans
)
276 if (asoc
->stats
.max_obs_rto
< (__u64
)trans
->rto
) {
277 asoc
->stats
.max_obs_rto
= trans
->rto
;
278 memset(&asoc
->stats
.obs_rto_ipaddr
, 0,
279 sizeof(struct sockaddr_storage
));
280 memcpy(&asoc
->stats
.obs_rto_ipaddr
, &trans
->ipaddr
,
281 trans
->af_specific
->sockaddr_len
);
286 * Macros for keeping a global reference of object allocations.
288 #ifdef CONFIG_SCTP_DBG_OBJCNT
290 extern atomic_t sctp_dbg_objcnt_sock
;
291 extern atomic_t sctp_dbg_objcnt_ep
;
292 extern atomic_t sctp_dbg_objcnt_assoc
;
293 extern atomic_t sctp_dbg_objcnt_transport
;
294 extern atomic_t sctp_dbg_objcnt_chunk
;
295 extern atomic_t sctp_dbg_objcnt_bind_addr
;
296 extern atomic_t sctp_dbg_objcnt_bind_bucket
;
297 extern atomic_t sctp_dbg_objcnt_addr
;
298 extern atomic_t sctp_dbg_objcnt_datamsg
;
299 extern atomic_t sctp_dbg_objcnt_keys
;
301 /* Macros to atomically increment/decrement objcnt counters. */
302 #define SCTP_DBG_OBJCNT_INC(name) \
303 atomic_inc(&sctp_dbg_objcnt_## name)
304 #define SCTP_DBG_OBJCNT_DEC(name) \
305 atomic_dec(&sctp_dbg_objcnt_## name)
306 #define SCTP_DBG_OBJCNT(name) \
307 atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
309 /* Macro to help create new entries in in the global array of
312 #define SCTP_DBG_OBJCNT_ENTRY(name) \
313 {.label= #name, .counter= &sctp_dbg_objcnt_## name}
315 void sctp_dbg_objcnt_init(struct net
*);
319 #define SCTP_DBG_OBJCNT_INC(name)
320 #define SCTP_DBG_OBJCNT_DEC(name)
322 static inline void sctp_dbg_objcnt_init(struct net
*net
) { return; }
324 #endif /* CONFIG_SCTP_DBG_OBJCOUNT */
326 #if defined CONFIG_SYSCTL
327 void sctp_sysctl_register(void);
328 void sctp_sysctl_unregister(void);
329 int sctp_sysctl_net_register(struct net
*net
);
330 void sctp_sysctl_net_unregister(struct net
*net
);
332 static inline void sctp_sysctl_register(void) { return; }
333 static inline void sctp_sysctl_unregister(void) { return; }
334 static inline int sctp_sysctl_net_register(struct net
*net
) { return 0; }
335 static inline void sctp_sysctl_net_unregister(struct net
*net
) { return; }
338 /* Size of Supported Address Parameter for 'x' address types. */
339 #define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
341 #if IS_ENABLED(CONFIG_IPV6)
343 void sctp_v6_pf_init(void);
344 void sctp_v6_pf_exit(void);
345 int sctp_v6_protosw_init(void);
346 void sctp_v6_protosw_exit(void);
347 int sctp_v6_add_protocol(void);
348 void sctp_v6_del_protocol(void);
350 #else /* #ifdef defined(CONFIG_IPV6) */
352 static inline void sctp_v6_pf_init(void) { return; }
353 static inline void sctp_v6_pf_exit(void) { return; }
354 static inline int sctp_v6_protosw_init(void) { return 0; }
355 static inline void sctp_v6_protosw_exit(void) { return; }
356 static inline int sctp_v6_add_protocol(void) { return 0; }
357 static inline void sctp_v6_del_protocol(void) { return; }
359 #endif /* #if defined(CONFIG_IPV6) */
362 /* Map an association to an assoc_id. */
363 static inline sctp_assoc_t
sctp_assoc2id(const struct sctp_association
*asoc
)
365 return asoc
? asoc
->assoc_id
: 0;
368 static inline enum sctp_sstat_state
369 sctp_assoc_to_state(const struct sctp_association
*asoc
)
371 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
372 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
373 * start at =1 in user space, but actually as =0 in kernel space.
374 * Now that we can not break user space and SCTP_EMPTY is exposed
375 * there, we need to fix it up with an ugly offset not to break
378 return asoc
->state
+ 1;
381 /* Look up the association by its id. */
382 struct sctp_association
*sctp_id2assoc(struct sock
*sk
, sctp_assoc_t id
);
384 int sctp_do_peeloff(struct sock
*sk
, sctp_assoc_t id
, struct socket
**sockp
);
386 /* A macro to walk a list of skbs. */
387 #define sctp_skb_for_each(pos, head, tmp) \
388 skb_queue_walk_safe(head, pos, tmp)
391 * sctp_list_dequeue - remove from the head of the queue
392 * @list: list to dequeue from
394 * Remove the head of the list. The head item is
395 * returned or %NULL if the list is empty.
398 static inline struct list_head
*sctp_list_dequeue(struct list_head
*list
)
400 struct list_head
*result
= NULL
;
402 if (!list_empty(list
)) {
404 list_del_init(result
);
409 /* SCTP version of skb_set_owner_r. We need this one because
410 * of the way we have to do receive buffer accounting on bundled
413 static inline void sctp_skb_set_owner_r(struct sk_buff
*skb
, struct sock
*sk
)
415 struct sctp_ulpevent
*event
= sctp_skb2event(skb
);
419 skb
->destructor
= sctp_sock_rfree
;
420 atomic_add(event
->rmem_len
, &sk
->sk_rmem_alloc
);
422 * This mimics the behavior of skb_set_owner_r
424 sk_mem_charge(sk
, event
->rmem_len
);
427 /* Tests if the list has one and only one entry. */
428 static inline int sctp_list_single_entry(struct list_head
*head
)
430 return (head
->next
!= head
) && (head
->next
== head
->prev
);
433 static inline bool sctp_chunk_pending(const struct sctp_chunk
*chunk
)
435 return !list_empty(&chunk
->list
);
438 /* Walk through a list of TLV parameters. Don't trust the
439 * individual parameter lengths and instead depend on
440 * the chunk length to indicate when to stop. Make sure
441 * there is room for a param header too.
443 #define sctp_walk_params(pos, chunk, member)\
444 _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
446 #define _sctp_walk_params(pos, chunk, end, member)\
447 for (pos.v = chunk->member;\
448 (pos.v + offsetof(struct sctp_paramhdr, length) + sizeof(pos.p->length) <=\
449 (void *)chunk + end) &&\
450 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
451 ntohs(pos.p->length) >= sizeof(struct sctp_paramhdr);\
452 pos.v += SCTP_PAD4(ntohs(pos.p->length)))
454 #define sctp_walk_errors(err, chunk_hdr)\
455 _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
457 #define _sctp_walk_errors(err, chunk_hdr, end)\
458 for (err = (struct sctp_errhdr *)((void *)chunk_hdr + \
459 sizeof(struct sctp_chunkhdr));\
460 ((void *)err + offsetof(struct sctp_errhdr, length) + sizeof(err->length) <=\
461 (void *)chunk_hdr + end) &&\
462 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
463 ntohs(err->length) >= sizeof(struct sctp_errhdr); \
464 err = (struct sctp_errhdr *)((void *)err + SCTP_PAD4(ntohs(err->length))))
466 #define sctp_walk_fwdtsn(pos, chunk)\
467 _sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
469 #define _sctp_walk_fwdtsn(pos, chunk, end)\
470 for (pos = chunk->subh.fwdtsn_hdr->skip;\
471 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
474 /* External references. */
476 extern struct proto sctp_prot
;
477 extern struct proto sctpv6_prot
;
478 void sctp_put_port(struct sock
*sk
);
480 extern struct idr sctp_assocs_id
;
481 extern spinlock_t sctp_assocs_id_lock
;
483 /* Static inline functions. */
485 /* Convert from an IP version number to an Address Family symbol. */
486 static inline int ipver2af(__u8 ipver
)
498 /* Convert from an address parameter type to an address family. */
499 static inline int param_type2af(__be16 type
)
502 case SCTP_PARAM_IPV4_ADDRESS
:
504 case SCTP_PARAM_IPV6_ADDRESS
:
511 /* Warning: The following hash functions assume a power of two 'size'. */
512 /* This is the hash function for the SCTP port hash table. */
513 static inline int sctp_phashfn(struct net
*net
, __u16 lport
)
515 return (net_hash_mix(net
) + lport
) & (sctp_port_hashsize
- 1);
518 /* This is the hash function for the endpoint hash table. */
519 static inline int sctp_ep_hashfn(struct net
*net
, __u16 lport
)
521 return (net_hash_mix(net
) + lport
) & (sctp_ep_hashsize
- 1);
524 #define sctp_for_each_hentry(epb, head) \
525 hlist_for_each_entry(epb, head, node)
527 /* Is a socket of this style? */
528 #define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
529 static inline int __sctp_style(const struct sock
*sk
,
530 enum sctp_socket_type style
)
532 return sctp_sk(sk
)->type
== style
;
535 /* Is the association in this state? */
536 #define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
537 static inline int __sctp_state(const struct sctp_association
*asoc
,
538 enum sctp_state state
)
540 return asoc
->state
== state
;
543 /* Is the socket in this state? */
544 #define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
545 static inline int __sctp_sstate(const struct sock
*sk
,
546 enum sctp_sock_state state
)
548 return sk
->sk_state
== state
;
551 /* Map v4-mapped v6 address back to v4 address */
552 static inline void sctp_v6_map_v4(union sctp_addr
*addr
)
554 addr
->v4
.sin_family
= AF_INET
;
555 addr
->v4
.sin_port
= addr
->v6
.sin6_port
;
556 addr
->v4
.sin_addr
.s_addr
= addr
->v6
.sin6_addr
.s6_addr32
[3];
559 /* Map v4 address to v4-mapped v6 address */
560 static inline void sctp_v4_map_v6(union sctp_addr
*addr
)
564 port
= addr
->v4
.sin_port
;
565 addr
->v6
.sin6_addr
.s6_addr32
[3] = addr
->v4
.sin_addr
.s_addr
;
566 addr
->v6
.sin6_port
= port
;
567 addr
->v6
.sin6_family
= AF_INET6
;
568 addr
->v6
.sin6_flowinfo
= 0;
569 addr
->v6
.sin6_scope_id
= 0;
570 addr
->v6
.sin6_addr
.s6_addr32
[0] = 0;
571 addr
->v6
.sin6_addr
.s6_addr32
[1] = 0;
572 addr
->v6
.sin6_addr
.s6_addr32
[2] = htonl(0x0000ffff);
575 /* The cookie is always 0 since this is how it's used in the
578 static inline struct dst_entry
*sctp_transport_dst_check(struct sctp_transport
*t
)
580 if (t
->dst
&& !dst_check(t
->dst
, t
->dst_cookie
))
581 sctp_transport_dst_release(t
);
586 /* Calculate max payload size given a MTU, or the total overhead if
589 static inline __u32
sctp_mtu_payload(const struct sctp_sock
*sp
,
590 __u32 mtu
, __u32 extra
)
592 __u32 overhead
= sizeof(struct sctphdr
) + extra
;
595 overhead
+= sp
->pf
->af
->net_header_len
;
597 overhead
+= sizeof(struct ipv6hdr
);
599 if (WARN_ON_ONCE(mtu
&& mtu
<= overhead
))
602 return mtu
? mtu
- overhead
: overhead
;
605 static inline __u32
sctp_dst_mtu(const struct dst_entry
*dst
)
607 return SCTP_TRUNC4(max_t(__u32
, dst_mtu(dst
),
608 SCTP_DEFAULT_MINSEGMENT
));
611 static inline bool sctp_transport_pmtu_check(struct sctp_transport
*t
)
613 __u32 pmtu
= sctp_dst_mtu(t
->dst
);
615 if (t
->pathmtu
== pmtu
)
623 static inline __u32
sctp_min_frag_point(struct sctp_sock
*sp
, __u16 datasize
)
625 return sctp_mtu_payload(sp
, SCTP_DEFAULT_MINSEGMENT
, datasize
);
628 #endif /* __net_sctp_h__ */