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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.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * The base lksctp header.
10 *
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)
15 * any later version.
16 *
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.
22 *
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/>.
26 *
27 * Please send any bug reports or fixes you make to the
28 * email address(es):
29 * lksctp developers <linux-sctp@vger.kernel.org>
30 *
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>
40 */
41
42#ifndef __net_sctp_h__
43#define __net_sctp_h__
44
45/* Header Strategy.
46 * Start getting some control over the header file depencies:
47 * includes
48 * constants
49 * structs
50 * prototypes
51 * macros, externs, and inlines
52 *
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.
56 */
57
58#include <linux/types.h>
59#include <linux/slab.h>
60#include <linux/in.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>
66
67#if IS_ENABLED(CONFIG_IPV6)
68#include <net/ipv6.h>
69#include <net/ip6_route.h>
70#endif
71
72#include <asm/uaccess.h>
73#include <asm/page.h>
74#include <net/sock.h>
75#include <net/snmp.h>
76#include <net/sctp/structs.h>
77#include <net/sctp/constants.h>
78
79#ifdef CONFIG_IP_SCTP_MODULE
80#define SCTP_PROTOSW_FLAG 0
81#else /* static! */
82#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
83#endif
84
85/* Round an int up to the next multiple of 4. */
86#define WORD_ROUND(s) (((s)+3)&~3)
87/* Truncate to the previous multiple of 4. */
88#define WORD_TRUNC(s) ((s)&~3)
89
90/*
91 * Function declarations.
92 */
93
94/*
95 * sctp/protocol.c
96 */
97int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
98 sctp_scope_t, gfp_t gfp, int flags);
99struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
100int sctp_register_pf(struct sctp_pf *, sa_family_t);
101void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
102
103/*
104 * sctp/socket.c
105 */
106int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
107int sctp_inet_listen(struct socket *sock, int backlog);
108void sctp_write_space(struct sock *sk);
109void sctp_data_ready(struct sock *sk);
110unsigned int sctp_poll(struct file *file, struct socket *sock,
111 poll_table *wait);
112void sctp_sock_rfree(struct sk_buff *skb);
113void sctp_copy_sock(struct sock *newsk, struct sock *sk,
114 struct sctp_association *asoc);
115extern struct percpu_counter sctp_sockets_allocated;
116int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
117struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
118
119/*
120 * sctp/primitive.c
121 */
122int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
123int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
124int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
125int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
126int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
127int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
128
129/*
130 * sctp/input.c
131 */
132int sctp_rcv(struct sk_buff *skb);
133void sctp_v4_err(struct sk_buff *skb, u32 info);
134void sctp_hash_endpoint(struct sctp_endpoint *);
135void sctp_unhash_endpoint(struct sctp_endpoint *);
136struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
137 struct sctphdr *, struct sctp_association **,
138 struct sctp_transport **);
139void sctp_err_finish(struct sock *, struct sctp_association *);
140void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
141 struct sctp_transport *t, __u32 pmtu);
142void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
143 struct sk_buff *);
144void sctp_icmp_proto_unreachable(struct sock *sk,
145 struct sctp_association *asoc,
146 struct sctp_transport *t);
147void sctp_backlog_migrate(struct sctp_association *assoc,
148 struct sock *oldsk, struct sock *newsk);
149int sctp_transport_hashtable_init(void);
150void sctp_transport_hashtable_destroy(void);
151void sctp_hash_transport(struct sctp_transport *t);
152void sctp_unhash_transport(struct sctp_transport *t);
153struct sctp_transport *sctp_addrs_lookup_transport(
154 struct net *net,
155 const union sctp_addr *laddr,
156 const union sctp_addr *paddr);
157struct sctp_transport *sctp_epaddr_lookup_transport(
158 const struct sctp_endpoint *ep,
159 const union sctp_addr *paddr);
160
161/*
162 * sctp/proc.c
163 */
164int sctp_snmp_proc_init(struct net *net);
165void sctp_snmp_proc_exit(struct net *net);
166int sctp_eps_proc_init(struct net *net);
167void sctp_eps_proc_exit(struct net *net);
168int sctp_assocs_proc_init(struct net *net);
169void sctp_assocs_proc_exit(struct net *net);
170int sctp_remaddr_proc_init(struct net *net);
171void sctp_remaddr_proc_exit(struct net *net);
172
173
174/*
175 * Module global variables
176 */
177
178 /*
179 * sctp/protocol.c
180 */
181extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
182extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
183extern long sysctl_sctp_mem[3];
184extern int sysctl_sctp_rmem[3];
185extern int sysctl_sctp_wmem[3];
186
187/*
188 * Section: Macros, externs, and inlines
189 */
190
191/* SCTP SNMP MIB stats handlers */
192#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
193#define SCTP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
194#define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
195#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
196
197/* sctp mib definitions */
198enum {
199 SCTP_MIB_NUM = 0,
200 SCTP_MIB_CURRESTAB, /* CurrEstab */
201 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */
202 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */
203 SCTP_MIB_ABORTEDS, /* Aborteds */
204 SCTP_MIB_SHUTDOWNS, /* Shutdowns */
205 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */
206 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */
207 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */
208 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */
209 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */
210 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */
211 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */
212 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */
213 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */
214 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */
215 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */
216 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */
217 SCTP_MIB_T1_INIT_EXPIREDS,
218 SCTP_MIB_T1_COOKIE_EXPIREDS,
219 SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
220 SCTP_MIB_T3_RTX_EXPIREDS,
221 SCTP_MIB_T4_RTO_EXPIREDS,
222 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
223 SCTP_MIB_DELAY_SACK_EXPIREDS,
224 SCTP_MIB_AUTOCLOSE_EXPIREDS,
225 SCTP_MIB_T1_RETRANSMITS,
226 SCTP_MIB_T3_RETRANSMITS,
227 SCTP_MIB_PMTUD_RETRANSMITS,
228 SCTP_MIB_FAST_RETRANSMITS,
229 SCTP_MIB_IN_PKT_SOFTIRQ,
230 SCTP_MIB_IN_PKT_BACKLOG,
231 SCTP_MIB_IN_PKT_DISCARDS,
232 SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
233 __SCTP_MIB_MAX
234};
235
236#define SCTP_MIB_MAX __SCTP_MIB_MAX
237struct sctp_mib {
238 unsigned long mibs[SCTP_MIB_MAX];
239};
240
241/* helper function to track stats about max rto and related transport */
242static inline void sctp_max_rto(struct sctp_association *asoc,
243 struct sctp_transport *trans)
244{
245 if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
246 asoc->stats.max_obs_rto = trans->rto;
247 memset(&asoc->stats.obs_rto_ipaddr, 0,
248 sizeof(struct sockaddr_storage));
249 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
250 trans->af_specific->sockaddr_len);
251 }
252}
253
254/*
255 * Macros for keeping a global reference of object allocations.
256 */
257#ifdef CONFIG_SCTP_DBG_OBJCNT
258
259extern atomic_t sctp_dbg_objcnt_sock;
260extern atomic_t sctp_dbg_objcnt_ep;
261extern atomic_t sctp_dbg_objcnt_assoc;
262extern atomic_t sctp_dbg_objcnt_transport;
263extern atomic_t sctp_dbg_objcnt_chunk;
264extern atomic_t sctp_dbg_objcnt_bind_addr;
265extern atomic_t sctp_dbg_objcnt_bind_bucket;
266extern atomic_t sctp_dbg_objcnt_addr;
267extern atomic_t sctp_dbg_objcnt_ssnmap;
268extern atomic_t sctp_dbg_objcnt_datamsg;
269extern atomic_t sctp_dbg_objcnt_keys;
270
271/* Macros to atomically increment/decrement objcnt counters. */
272#define SCTP_DBG_OBJCNT_INC(name) \
273atomic_inc(&sctp_dbg_objcnt_## name)
274#define SCTP_DBG_OBJCNT_DEC(name) \
275atomic_dec(&sctp_dbg_objcnt_## name)
276#define SCTP_DBG_OBJCNT(name) \
277atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
278
279/* Macro to help create new entries in in the global array of
280 * objcnt counters.
281 */
282#define SCTP_DBG_OBJCNT_ENTRY(name) \
283{.label= #name, .counter= &sctp_dbg_objcnt_## name}
284
285void sctp_dbg_objcnt_init(struct net *);
286void sctp_dbg_objcnt_exit(struct net *);
287
288#else
289
290#define SCTP_DBG_OBJCNT_INC(name)
291#define SCTP_DBG_OBJCNT_DEC(name)
292
293static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
294static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
295
296#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
297
298#if defined CONFIG_SYSCTL
299void sctp_sysctl_register(void);
300void sctp_sysctl_unregister(void);
301int sctp_sysctl_net_register(struct net *net);
302void sctp_sysctl_net_unregister(struct net *net);
303#else
304static inline void sctp_sysctl_register(void) { return; }
305static inline void sctp_sysctl_unregister(void) { return; }
306static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
307static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
308#endif
309
310/* Size of Supported Address Parameter for 'x' address types. */
311#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
312
313#if IS_ENABLED(CONFIG_IPV6)
314
315void sctp_v6_pf_init(void);
316void sctp_v6_pf_exit(void);
317int sctp_v6_protosw_init(void);
318void sctp_v6_protosw_exit(void);
319int sctp_v6_add_protocol(void);
320void sctp_v6_del_protocol(void);
321
322#else /* #ifdef defined(CONFIG_IPV6) */
323
324static inline void sctp_v6_pf_init(void) { return; }
325static inline void sctp_v6_pf_exit(void) { return; }
326static inline int sctp_v6_protosw_init(void) { return 0; }
327static inline void sctp_v6_protosw_exit(void) { return; }
328static inline int sctp_v6_add_protocol(void) { return 0; }
329static inline void sctp_v6_del_protocol(void) { return; }
330
331#endif /* #if defined(CONFIG_IPV6) */
332
333
334/* Map an association to an assoc_id. */
335static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
336{
337 return asoc ? asoc->assoc_id : 0;
338}
339
340static inline enum sctp_sstat_state
341sctp_assoc_to_state(const struct sctp_association *asoc)
342{
343 /* SCTP's uapi always had SCTP_EMPTY(=0) as a dummy state, but we
344 * got rid of it in kernel space. Therefore SCTP_CLOSED et al
345 * start at =1 in user space, but actually as =0 in kernel space.
346 * Now that we can not break user space and SCTP_EMPTY is exposed
347 * there, we need to fix it up with an ugly offset not to break
348 * applications. :(
349 */
350 return asoc->state + 1;
351}
352
353/* Look up the association by its id. */
354struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
355
356int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
357
358/* A macro to walk a list of skbs. */
359#define sctp_skb_for_each(pos, head, tmp) \
360 skb_queue_walk_safe(head, pos, tmp)
361
362/* A helper to append an entire skb list (list) to another (head). */
363static inline void sctp_skb_list_tail(struct sk_buff_head *list,
364 struct sk_buff_head *head)
365{
366 unsigned long flags;
367
368 spin_lock_irqsave(&head->lock, flags);
369 spin_lock(&list->lock);
370
371 skb_queue_splice_tail_init(list, head);
372
373 spin_unlock(&list->lock);
374 spin_unlock_irqrestore(&head->lock, flags);
375}
376
377/**
378 * sctp_list_dequeue - remove from the head of the queue
379 * @list: list to dequeue from
380 *
381 * Remove the head of the list. The head item is
382 * returned or %NULL if the list is empty.
383 */
384
385static inline struct list_head *sctp_list_dequeue(struct list_head *list)
386{
387 struct list_head *result = NULL;
388
389 if (!list_empty(list)) {
390 result = list->next;
391 list_del_init(result);
392 }
393 return result;
394}
395
396/* SCTP version of skb_set_owner_r. We need this one because
397 * of the way we have to do receive buffer accounting on bundled
398 * chunks.
399 */
400static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
401{
402 struct sctp_ulpevent *event = sctp_skb2event(skb);
403
404 skb_orphan(skb);
405 skb->sk = sk;
406 skb->destructor = sctp_sock_rfree;
407 atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
408 /*
409 * This mimics the behavior of skb_set_owner_r
410 */
411 sk->sk_forward_alloc -= event->rmem_len;
412}
413
414/* Tests if the list has one and only one entry. */
415static inline int sctp_list_single_entry(struct list_head *head)
416{
417 return (head->next != head) && (head->next == head->prev);
418}
419
420/* Break down data chunks at this point. */
421static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
422{
423 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
424 int frag = pmtu;
425
426 frag -= sp->pf->af->net_header_len;
427 frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
428
429 if (asoc->user_frag)
430 frag = min_t(int, frag, asoc->user_frag);
431
432 frag = WORD_TRUNC(min_t(int, frag, SCTP_MAX_CHUNK_LEN));
433
434 return frag;
435}
436
437static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
438{
439
440 sctp_assoc_sync_pmtu(sk, asoc);
441 asoc->pmtu_pending = 0;
442}
443
444static inline bool sctp_chunk_pending(const struct sctp_chunk *chunk)
445{
446 return !list_empty(&chunk->list);
447}
448
449/* Walk through a list of TLV parameters. Don't trust the
450 * individual parameter lengths and instead depend on
451 * the chunk length to indicate when to stop. Make sure
452 * there is room for a param header too.
453 */
454#define sctp_walk_params(pos, chunk, member)\
455_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
456
457#define _sctp_walk_params(pos, chunk, end, member)\
458for (pos.v = chunk->member;\
459 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
460 ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
461 pos.v += WORD_ROUND(ntohs(pos.p->length)))
462
463#define sctp_walk_errors(err, chunk_hdr)\
464_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
465
466#define _sctp_walk_errors(err, chunk_hdr, end)\
467for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
468 sizeof(sctp_chunkhdr_t));\
469 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
470 ntohs(err->length) >= sizeof(sctp_errhdr_t); \
471 err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
472
473#define sctp_walk_fwdtsn(pos, chunk)\
474_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
475
476#define _sctp_walk_fwdtsn(pos, chunk, end)\
477for (pos = chunk->subh.fwdtsn_hdr->skip;\
478 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
479 pos++)
480
481/* External references. */
482
483extern struct proto sctp_prot;
484extern struct proto sctpv6_prot;
485void sctp_put_port(struct sock *sk);
486
487extern struct idr sctp_assocs_id;
488extern spinlock_t sctp_assocs_id_lock;
489
490/* Static inline functions. */
491
492/* Convert from an IP version number to an Address Family symbol. */
493static inline int ipver2af(__u8 ipver)
494{
495 switch (ipver) {
496 case 4:
497 return AF_INET;
498 case 6:
499 return AF_INET6;
500 default:
501 return 0;
502 }
503}
504
505/* Convert from an address parameter type to an address family. */
506static inline int param_type2af(__be16 type)
507{
508 switch (type) {
509 case SCTP_PARAM_IPV4_ADDRESS:
510 return AF_INET;
511 case SCTP_PARAM_IPV6_ADDRESS:
512 return AF_INET6;
513 default:
514 return 0;
515 }
516}
517
518/* Warning: The following hash functions assume a power of two 'size'. */
519/* This is the hash function for the SCTP port hash table. */
520static inline int sctp_phashfn(struct net *net, __u16 lport)
521{
522 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
523}
524
525/* This is the hash function for the endpoint hash table. */
526static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
527{
528 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
529}
530
531#define sctp_for_each_hentry(epb, head) \
532 hlist_for_each_entry(epb, head, node)
533
534/* Is a socket of this style? */
535#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
536static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
537{
538 return sctp_sk(sk)->type == style;
539}
540
541/* Is the association in this state? */
542#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
543static inline int __sctp_state(const struct sctp_association *asoc,
544 sctp_state_t state)
545{
546 return asoc->state == state;
547}
548
549/* Is the socket in this state? */
550#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
551static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
552{
553 return sk->sk_state == state;
554}
555
556/* Map v4-mapped v6 address back to v4 address */
557static inline void sctp_v6_map_v4(union sctp_addr *addr)
558{
559 addr->v4.sin_family = AF_INET;
560 addr->v4.sin_port = addr->v6.sin6_port;
561 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
562}
563
564/* Map v4 address to v4-mapped v6 address */
565static inline void sctp_v4_map_v6(union sctp_addr *addr)
566{
567 __be16 port;
568
569 port = addr->v4.sin_port;
570 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
571 addr->v6.sin6_port = port;
572 addr->v6.sin6_family = AF_INET6;
573 addr->v6.sin6_flowinfo = 0;
574 addr->v6.sin6_scope_id = 0;
575 addr->v6.sin6_addr.s6_addr32[0] = 0;
576 addr->v6.sin6_addr.s6_addr32[1] = 0;
577 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
578}
579
580/* The cookie is always 0 since this is how it's used in the
581 * pmtu code.
582 */
583static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
584{
585 if (t->dst && !dst_check(t->dst, t->dst_cookie)) {
586 dst_release(t->dst);
587 t->dst = NULL;
588 }
589
590 return t->dst;
591}
592
593#endif /* __net_sctp_h__ */
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.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * The base lksctp header.
10 *
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)
15 * any later version.
16 *
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.
22 *
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/>.
26 *
27 * Please send any bug reports or fixes you make to the
28 * email address(es):
29 * lksctp developers <linux-sctp@vger.kernel.org>
30 *
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>
40 */
41
42#ifndef __net_sctp_h__
43#define __net_sctp_h__
44
45/* Header Strategy.
46 * Start getting some control over the header file depencies:
47 * includes
48 * constants
49 * structs
50 * prototypes
51 * macros, externs, and inlines
52 *
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.
56 */
57
58#include <linux/types.h>
59#include <linux/slab.h>
60#include <linux/in.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>
66
67#if IS_ENABLED(CONFIG_IPV6)
68#include <net/ipv6.h>
69#include <net/ip6_route.h>
70#endif
71
72#include <asm/uaccess.h>
73#include <asm/page.h>
74#include <net/sock.h>
75#include <net/snmp.h>
76#include <net/sctp/structs.h>
77#include <net/sctp/constants.h>
78
79#ifdef CONFIG_IP_SCTP_MODULE
80#define SCTP_PROTOSW_FLAG 0
81#else /* static! */
82#define SCTP_PROTOSW_FLAG INET_PROTOSW_PERMANENT
83#endif
84
85/*
86 * Function declarations.
87 */
88
89/*
90 * sctp/protocol.c
91 */
92int sctp_copy_local_addr_list(struct net *, struct sctp_bind_addr *,
93 sctp_scope_t, gfp_t gfp, int flags);
94struct sctp_pf *sctp_get_pf_specific(sa_family_t family);
95int sctp_register_pf(struct sctp_pf *, sa_family_t);
96void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
97
98/*
99 * sctp/socket.c
100 */
101int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
102int sctp_inet_listen(struct socket *sock, int backlog);
103void sctp_write_space(struct sock *sk);
104void sctp_data_ready(struct sock *sk);
105unsigned int sctp_poll(struct file *file, struct socket *sock,
106 poll_table *wait);
107void sctp_sock_rfree(struct sk_buff *skb);
108void sctp_copy_sock(struct sock *newsk, struct sock *sk,
109 struct sctp_association *asoc);
110extern struct percpu_counter sctp_sockets_allocated;
111int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
112
113/*
114 * sctp/primitive.c
115 */
116int sctp_primitive_ASSOCIATE(struct net *, struct sctp_association *, void *arg);
117int sctp_primitive_SHUTDOWN(struct net *, struct sctp_association *, void *arg);
118int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
119int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
120int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
121int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
122
123/*
124 * sctp/input.c
125 */
126int sctp_rcv(struct sk_buff *skb);
127void sctp_v4_err(struct sk_buff *skb, u32 info);
128void sctp_hash_established(struct sctp_association *);
129void sctp_unhash_established(struct sctp_association *);
130void sctp_hash_endpoint(struct sctp_endpoint *);
131void sctp_unhash_endpoint(struct sctp_endpoint *);
132struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
133 struct sctphdr *, struct sctp_association **,
134 struct sctp_transport **);
135void sctp_err_finish(struct sock *, struct sctp_association *);
136void sctp_icmp_frag_needed(struct sock *, struct sctp_association *,
137 struct sctp_transport *t, __u32 pmtu);
138void sctp_icmp_redirect(struct sock *, struct sctp_transport *,
139 struct sk_buff *);
140void sctp_icmp_proto_unreachable(struct sock *sk,
141 struct sctp_association *asoc,
142 struct sctp_transport *t);
143void sctp_backlog_migrate(struct sctp_association *assoc,
144 struct sock *oldsk, struct sock *newsk);
145
146/*
147 * sctp/proc.c
148 */
149int sctp_snmp_proc_init(struct net *net);
150void sctp_snmp_proc_exit(struct net *net);
151int sctp_eps_proc_init(struct net *net);
152void sctp_eps_proc_exit(struct net *net);
153int sctp_assocs_proc_init(struct net *net);
154void sctp_assocs_proc_exit(struct net *net);
155int sctp_remaddr_proc_init(struct net *net);
156void sctp_remaddr_proc_exit(struct net *net);
157
158
159/*
160 * Module global variables
161 */
162
163 /*
164 * sctp/protocol.c
165 */
166extern struct kmem_cache *sctp_chunk_cachep __read_mostly;
167extern struct kmem_cache *sctp_bucket_cachep __read_mostly;
168
169/*
170 * Section: Macros, externs, and inlines
171 */
172
173/* SCTP SNMP MIB stats handlers */
174#define SCTP_INC_STATS(net, field) SNMP_INC_STATS((net)->sctp.sctp_statistics, field)
175#define SCTP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->sctp.sctp_statistics, field)
176#define SCTP_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->sctp.sctp_statistics, field)
177#define SCTP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->sctp.sctp_statistics, field)
178
179/* sctp mib definitions */
180enum {
181 SCTP_MIB_NUM = 0,
182 SCTP_MIB_CURRESTAB, /* CurrEstab */
183 SCTP_MIB_ACTIVEESTABS, /* ActiveEstabs */
184 SCTP_MIB_PASSIVEESTABS, /* PassiveEstabs */
185 SCTP_MIB_ABORTEDS, /* Aborteds */
186 SCTP_MIB_SHUTDOWNS, /* Shutdowns */
187 SCTP_MIB_OUTOFBLUES, /* OutOfBlues */
188 SCTP_MIB_CHECKSUMERRORS, /* ChecksumErrors */
189 SCTP_MIB_OUTCTRLCHUNKS, /* OutCtrlChunks */
190 SCTP_MIB_OUTORDERCHUNKS, /* OutOrderChunks */
191 SCTP_MIB_OUTUNORDERCHUNKS, /* OutUnorderChunks */
192 SCTP_MIB_INCTRLCHUNKS, /* InCtrlChunks */
193 SCTP_MIB_INORDERCHUNKS, /* InOrderChunks */
194 SCTP_MIB_INUNORDERCHUNKS, /* InUnorderChunks */
195 SCTP_MIB_FRAGUSRMSGS, /* FragUsrMsgs */
196 SCTP_MIB_REASMUSRMSGS, /* ReasmUsrMsgs */
197 SCTP_MIB_OUTSCTPPACKS, /* OutSCTPPacks */
198 SCTP_MIB_INSCTPPACKS, /* InSCTPPacks */
199 SCTP_MIB_T1_INIT_EXPIREDS,
200 SCTP_MIB_T1_COOKIE_EXPIREDS,
201 SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
202 SCTP_MIB_T3_RTX_EXPIREDS,
203 SCTP_MIB_T4_RTO_EXPIREDS,
204 SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
205 SCTP_MIB_DELAY_SACK_EXPIREDS,
206 SCTP_MIB_AUTOCLOSE_EXPIREDS,
207 SCTP_MIB_T1_RETRANSMITS,
208 SCTP_MIB_T3_RETRANSMITS,
209 SCTP_MIB_PMTUD_RETRANSMITS,
210 SCTP_MIB_FAST_RETRANSMITS,
211 SCTP_MIB_IN_PKT_SOFTIRQ,
212 SCTP_MIB_IN_PKT_BACKLOG,
213 SCTP_MIB_IN_PKT_DISCARDS,
214 SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
215 __SCTP_MIB_MAX
216};
217
218#define SCTP_MIB_MAX __SCTP_MIB_MAX
219struct sctp_mib {
220 unsigned long mibs[SCTP_MIB_MAX];
221};
222
223/* helper function to track stats about max rto and related transport */
224static inline void sctp_max_rto(struct sctp_association *asoc,
225 struct sctp_transport *trans)
226{
227 if (asoc->stats.max_obs_rto < (__u64)trans->rto) {
228 asoc->stats.max_obs_rto = trans->rto;
229 memset(&asoc->stats.obs_rto_ipaddr, 0,
230 sizeof(struct sockaddr_storage));
231 memcpy(&asoc->stats.obs_rto_ipaddr, &trans->ipaddr,
232 trans->af_specific->sockaddr_len);
233 }
234}
235
236/*
237 * Macros for keeping a global reference of object allocations.
238 */
239#ifdef CONFIG_SCTP_DBG_OBJCNT
240
241extern atomic_t sctp_dbg_objcnt_sock;
242extern atomic_t sctp_dbg_objcnt_ep;
243extern atomic_t sctp_dbg_objcnt_assoc;
244extern atomic_t sctp_dbg_objcnt_transport;
245extern atomic_t sctp_dbg_objcnt_chunk;
246extern atomic_t sctp_dbg_objcnt_bind_addr;
247extern atomic_t sctp_dbg_objcnt_bind_bucket;
248extern atomic_t sctp_dbg_objcnt_addr;
249extern atomic_t sctp_dbg_objcnt_ssnmap;
250extern atomic_t sctp_dbg_objcnt_datamsg;
251extern atomic_t sctp_dbg_objcnt_keys;
252
253/* Macros to atomically increment/decrement objcnt counters. */
254#define SCTP_DBG_OBJCNT_INC(name) \
255atomic_inc(&sctp_dbg_objcnt_## name)
256#define SCTP_DBG_OBJCNT_DEC(name) \
257atomic_dec(&sctp_dbg_objcnt_## name)
258#define SCTP_DBG_OBJCNT(name) \
259atomic_t sctp_dbg_objcnt_## name = ATOMIC_INIT(0)
260
261/* Macro to help create new entries in in the global array of
262 * objcnt counters.
263 */
264#define SCTP_DBG_OBJCNT_ENTRY(name) \
265{.label= #name, .counter= &sctp_dbg_objcnt_## name}
266
267void sctp_dbg_objcnt_init(struct net *);
268void sctp_dbg_objcnt_exit(struct net *);
269
270#else
271
272#define SCTP_DBG_OBJCNT_INC(name)
273#define SCTP_DBG_OBJCNT_DEC(name)
274
275static inline void sctp_dbg_objcnt_init(struct net *net) { return; }
276static inline void sctp_dbg_objcnt_exit(struct net *net) { return; }
277
278#endif /* CONFIG_SCTP_DBG_OBJCOUNT */
279
280#if defined CONFIG_SYSCTL
281void sctp_sysctl_register(void);
282void sctp_sysctl_unregister(void);
283int sctp_sysctl_net_register(struct net *net);
284void sctp_sysctl_net_unregister(struct net *net);
285#else
286static inline void sctp_sysctl_register(void) { return; }
287static inline void sctp_sysctl_unregister(void) { return; }
288static inline int sctp_sysctl_net_register(struct net *net) { return 0; }
289static inline void sctp_sysctl_net_unregister(struct net *net) { return; }
290#endif
291
292/* Size of Supported Address Parameter for 'x' address types. */
293#define SCTP_SAT_LEN(x) (sizeof(struct sctp_paramhdr) + (x) * sizeof(__u16))
294
295#if IS_ENABLED(CONFIG_IPV6)
296
297void sctp_v6_pf_init(void);
298void sctp_v6_pf_exit(void);
299int sctp_v6_protosw_init(void);
300void sctp_v6_protosw_exit(void);
301int sctp_v6_add_protocol(void);
302void sctp_v6_del_protocol(void);
303
304#else /* #ifdef defined(CONFIG_IPV6) */
305
306static inline void sctp_v6_pf_init(void) { return; }
307static inline void sctp_v6_pf_exit(void) { return; }
308static inline int sctp_v6_protosw_init(void) { return 0; }
309static inline void sctp_v6_protosw_exit(void) { return; }
310static inline int sctp_v6_add_protocol(void) { return 0; }
311static inline void sctp_v6_del_protocol(void) { return; }
312
313#endif /* #if defined(CONFIG_IPV6) */
314
315
316/* Map an association to an assoc_id. */
317static inline sctp_assoc_t sctp_assoc2id(const struct sctp_association *asoc)
318{
319 return asoc ? asoc->assoc_id : 0;
320}
321
322/* Look up the association by its id. */
323struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id);
324
325int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp);
326
327/* A macro to walk a list of skbs. */
328#define sctp_skb_for_each(pos, head, tmp) \
329 skb_queue_walk_safe(head, pos, tmp)
330
331/* A helper to append an entire skb list (list) to another (head). */
332static inline void sctp_skb_list_tail(struct sk_buff_head *list,
333 struct sk_buff_head *head)
334{
335 unsigned long flags;
336
337 spin_lock_irqsave(&head->lock, flags);
338 spin_lock(&list->lock);
339
340 skb_queue_splice_tail_init(list, head);
341
342 spin_unlock(&list->lock);
343 spin_unlock_irqrestore(&head->lock, flags);
344}
345
346/**
347 * sctp_list_dequeue - remove from the head of the queue
348 * @list: list to dequeue from
349 *
350 * Remove the head of the list. The head item is
351 * returned or %NULL if the list is empty.
352 */
353
354static inline struct list_head *sctp_list_dequeue(struct list_head *list)
355{
356 struct list_head *result = NULL;
357
358 if (list->next != list) {
359 result = list->next;
360 list->next = result->next;
361 list->next->prev = list;
362 INIT_LIST_HEAD(result);
363 }
364 return result;
365}
366
367/* SCTP version of skb_set_owner_r. We need this one because
368 * of the way we have to do receive buffer accounting on bundled
369 * chunks.
370 */
371static inline void sctp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
372{
373 struct sctp_ulpevent *event = sctp_skb2event(skb);
374
375 skb_orphan(skb);
376 skb->sk = sk;
377 skb->destructor = sctp_sock_rfree;
378 atomic_add(event->rmem_len, &sk->sk_rmem_alloc);
379 /*
380 * This mimics the behavior of skb_set_owner_r
381 */
382 sk->sk_forward_alloc -= event->rmem_len;
383}
384
385/* Tests if the list has one and only one entry. */
386static inline int sctp_list_single_entry(struct list_head *head)
387{
388 return (head->next != head) && (head->next == head->prev);
389}
390
391/* Generate a random jitter in the range of -50% ~ +50% of input RTO. */
392static inline __s32 sctp_jitter(__u32 rto)
393{
394 static __u32 sctp_rand;
395 __s32 ret;
396
397 /* Avoid divide by zero. */
398 if (!rto)
399 rto = 1;
400
401 sctp_rand += jiffies;
402 sctp_rand ^= (sctp_rand << 12);
403 sctp_rand ^= (sctp_rand >> 20);
404
405 /* Choose random number from 0 to rto, then move to -50% ~ +50%
406 * of rto.
407 */
408 ret = sctp_rand % rto - (rto >> 1);
409 return ret;
410}
411
412/* Break down data chunks at this point. */
413static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
414{
415 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
416 int frag = pmtu;
417
418 frag -= sp->pf->af->net_header_len;
419 frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
420
421 if (asoc->user_frag)
422 frag = min_t(int, frag, asoc->user_frag);
423
424 frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);
425
426 return frag;
427}
428
429static inline void sctp_assoc_pending_pmtu(struct sock *sk, struct sctp_association *asoc)
430{
431
432 sctp_assoc_sync_pmtu(sk, asoc);
433 asoc->pmtu_pending = 0;
434}
435
436/* Walk through a list of TLV parameters. Don't trust the
437 * individual parameter lengths and instead depend on
438 * the chunk length to indicate when to stop. Make sure
439 * there is room for a param header too.
440 */
441#define sctp_walk_params(pos, chunk, member)\
442_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
443
444#define _sctp_walk_params(pos, chunk, end, member)\
445for (pos.v = chunk->member;\
446 pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
447 ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
448 pos.v += WORD_ROUND(ntohs(pos.p->length)))
449
450#define sctp_walk_errors(err, chunk_hdr)\
451_sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
452
453#define _sctp_walk_errors(err, chunk_hdr, end)\
454for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
455 sizeof(sctp_chunkhdr_t));\
456 (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
457 ntohs(err->length) >= sizeof(sctp_errhdr_t); \
458 err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))
459
460#define sctp_walk_fwdtsn(pos, chunk)\
461_sctp_walk_fwdtsn((pos), (chunk), ntohs((chunk)->chunk_hdr->length) - sizeof(struct sctp_fwdtsn_chunk))
462
463#define _sctp_walk_fwdtsn(pos, chunk, end)\
464for (pos = chunk->subh.fwdtsn_hdr->skip;\
465 (void *)pos <= (void *)chunk->subh.fwdtsn_hdr->skip + end - sizeof(struct sctp_fwdtsn_skip);\
466 pos++)
467
468/* Round an int up to the next multiple of 4. */
469#define WORD_ROUND(s) (((s)+3)&~3)
470
471/* External references. */
472
473extern struct proto sctp_prot;
474extern struct proto sctpv6_prot;
475void sctp_put_port(struct sock *sk);
476
477extern struct idr sctp_assocs_id;
478extern spinlock_t sctp_assocs_id_lock;
479
480/* Static inline functions. */
481
482/* Convert from an IP version number to an Address Family symbol. */
483static inline int ipver2af(__u8 ipver)
484{
485 switch (ipver) {
486 case 4:
487 return AF_INET;
488 case 6:
489 return AF_INET6;
490 default:
491 return 0;
492 }
493}
494
495/* Convert from an address parameter type to an address family. */
496static inline int param_type2af(__be16 type)
497{
498 switch (type) {
499 case SCTP_PARAM_IPV4_ADDRESS:
500 return AF_INET;
501 case SCTP_PARAM_IPV6_ADDRESS:
502 return AF_INET6;
503 default:
504 return 0;
505 }
506}
507
508/* Warning: The following hash functions assume a power of two 'size'. */
509/* This is the hash function for the SCTP port hash table. */
510static inline int sctp_phashfn(struct net *net, __u16 lport)
511{
512 return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
513}
514
515/* This is the hash function for the endpoint hash table. */
516static inline int sctp_ep_hashfn(struct net *net, __u16 lport)
517{
518 return (net_hash_mix(net) + lport) & (sctp_ep_hashsize - 1);
519}
520
521/* This is the hash function for the association hash table. */
522static inline int sctp_assoc_hashfn(struct net *net, __u16 lport, __u16 rport)
523{
524 int h = (lport << 16) + rport + net_hash_mix(net);
525 h ^= h>>8;
526 return h & (sctp_assoc_hashsize - 1);
527}
528
529/* This is the hash function for the association hash table. This is
530 * not used yet, but could be used as a better hash function when
531 * we have a vtag.
532 */
533static inline int sctp_vtag_hashfn(__u16 lport, __u16 rport, __u32 vtag)
534{
535 int h = (lport << 16) + rport;
536 h ^= vtag;
537 return h & (sctp_assoc_hashsize - 1);
538}
539
540#define sctp_for_each_hentry(epb, head) \
541 hlist_for_each_entry(epb, head, node)
542
543/* Is a socket of this style? */
544#define sctp_style(sk, style) __sctp_style((sk), (SCTP_SOCKET_##style))
545static inline int __sctp_style(const struct sock *sk, sctp_socket_type_t style)
546{
547 return sctp_sk(sk)->type == style;
548}
549
550/* Is the association in this state? */
551#define sctp_state(asoc, state) __sctp_state((asoc), (SCTP_STATE_##state))
552static inline int __sctp_state(const struct sctp_association *asoc,
553 sctp_state_t state)
554{
555 return asoc->state == state;
556}
557
558/* Is the socket in this state? */
559#define sctp_sstate(sk, state) __sctp_sstate((sk), (SCTP_SS_##state))
560static inline int __sctp_sstate(const struct sock *sk, sctp_sock_state_t state)
561{
562 return sk->sk_state == state;
563}
564
565/* Map v4-mapped v6 address back to v4 address */
566static inline void sctp_v6_map_v4(union sctp_addr *addr)
567{
568 addr->v4.sin_family = AF_INET;
569 addr->v4.sin_port = addr->v6.sin6_port;
570 addr->v4.sin_addr.s_addr = addr->v6.sin6_addr.s6_addr32[3];
571}
572
573/* Map v4 address to v4-mapped v6 address */
574static inline void sctp_v4_map_v6(union sctp_addr *addr)
575{
576 addr->v6.sin6_family = AF_INET6;
577 addr->v6.sin6_port = addr->v4.sin_port;
578 addr->v6.sin6_addr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
579 addr->v6.sin6_addr.s6_addr32[0] = 0;
580 addr->v6.sin6_addr.s6_addr32[1] = 0;
581 addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff);
582}
583
584/* The cookie is always 0 since this is how it's used in the
585 * pmtu code.
586 */
587static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
588{
589 if (t->dst && !dst_check(t->dst, t->dst_cookie)) {
590 dst_release(t->dst);
591 t->dst = NULL;
592 }
593
594 return t->dst;
595}
596
597#endif /* __net_sctp_h__ */