Root/net/tipc/link.c

1/*
2 * net/tipc/link.c: TIPC link code
3 *
4 * Copyright (c) 1996-2007, Ericsson AB
5 * Copyright (c) 2004-2007, Wind River Systems
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the names of the copyright holders nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * Alternatively, this software may be distributed under the terms of the
21 * GNU General Public License ("GPL") version 2 as published by the Free
22 * Software Foundation.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include "core.h"
38#include "dbg.h"
39#include "link.h"
40#include "net.h"
41#include "node.h"
42#include "port.h"
43#include "addr.h"
44#include "node_subscr.h"
45#include "name_distr.h"
46#include "bearer.h"
47#include "name_table.h"
48#include "discover.h"
49#include "config.h"
50#include "bcast.h"
51
52
53/*
54 * Out-of-range value for link session numbers
55 */
56
57#define INVALID_SESSION 0x10000
58
59/*
60 * Limit for deferred reception queue:
61 */
62
63#define DEF_QUEUE_LIMIT 256u
64
65/*
66 * Link state events:
67 */
68
69#define STARTING_EVT 856384768 /* link processing trigger */
70#define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */
71#define TIMEOUT_EVT 560817u /* link timer expired */
72
73/*
74 * The following two 'message types' is really just implementation
75 * data conveniently stored in the message header.
76 * They must not be considered part of the protocol
77 */
78#define OPEN_MSG 0
79#define CLOSED_MSG 1
80
81/*
82 * State value stored in 'exp_msg_count'
83 */
84
85#define START_CHANGEOVER 100000u
86
87/**
88 * struct link_name - deconstructed link name
89 * @addr_local: network address of node at this end
90 * @if_local: name of interface at this end
91 * @addr_peer: network address of node at far end
92 * @if_peer: name of interface at far end
93 */
94
95struct link_name {
96    u32 addr_local;
97    char if_local[TIPC_MAX_IF_NAME];
98    u32 addr_peer;
99    char if_peer[TIPC_MAX_IF_NAME];
100};
101
102#if 0
103
104/* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
105
106/**
107 * struct link_event - link up/down event notification
108 */
109
110struct link_event {
111    u32 addr;
112    int up;
113    void (*fcn)(u32, char *, int);
114    char name[TIPC_MAX_LINK_NAME];
115};
116
117#endif
118
119static void link_handle_out_of_seq_msg(struct link *l_ptr,
120                       struct sk_buff *buf);
121static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf);
122static int link_recv_changeover_msg(struct link **l_ptr, struct sk_buff **buf);
123static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
124static int link_send_sections_long(struct port *sender,
125                    struct iovec const *msg_sect,
126                    u32 num_sect, u32 destnode);
127static void link_check_defragm_bufs(struct link *l_ptr);
128static void link_state_event(struct link *l_ptr, u32 event);
129static void link_reset_statistics(struct link *l_ptr);
130static void link_print(struct link *l_ptr, struct print_buf *buf,
131               const char *str);
132
133/*
134 * Debugging code used by link routines only
135 *
136 * When debugging link problems on a system that has multiple links,
137 * the standard TIPC debugging routines may not be useful since they
138 * allow the output from multiple links to be intermixed. For this reason
139 * routines of the form "dbg_link_XXX()" have been created that will capture
140 * debug info into a link's personal print buffer, which can then be dumped
141 * into the TIPC system log (TIPC_LOG) upon request.
142 *
143 * To enable per-link debugging, use LINK_LOG_BUF_SIZE to specify the size
144 * of the print buffer used by each link. If LINK_LOG_BUF_SIZE is set to 0,
145 * the dbg_link_XXX() routines simply send their output to the standard
146 * debug print buffer (DBG_OUTPUT), if it has been defined; this can be useful
147 * when there is only a single link in the system being debugged.
148 *
149 * Notes:
150 * - When enabled, LINK_LOG_BUF_SIZE should be set to at least TIPC_PB_MIN_SIZE
151 * - "l_ptr" must be valid when using dbg_link_XXX() macros
152 */
153
154#define LINK_LOG_BUF_SIZE 0
155
156#define dbg_link(fmt, arg...) \
157    do { \
158        if (LINK_LOG_BUF_SIZE) \
159            tipc_printf(&l_ptr->print_buf, fmt, ## arg); \
160    } while (0)
161#define dbg_link_msg(msg, txt) \
162    do { \
163        if (LINK_LOG_BUF_SIZE) \
164            tipc_msg_dbg(&l_ptr->print_buf, msg, txt); \
165    } while (0)
166#define dbg_link_state(txt) \
167    do { \
168        if (LINK_LOG_BUF_SIZE) \
169            link_print(l_ptr, &l_ptr->print_buf, txt); \
170    } while (0)
171#define dbg_link_dump() do { \
172    if (LINK_LOG_BUF_SIZE) { \
173        tipc_printf(LOG, "\n\nDumping link <%s>:\n", l_ptr->name); \
174        tipc_printbuf_move(LOG, &l_ptr->print_buf); \
175    } \
176} while (0)
177
178static void dbg_print_link(struct link *l_ptr, const char *str)
179{
180    if (DBG_OUTPUT != TIPC_NULL)
181        link_print(l_ptr, DBG_OUTPUT, str);
182}
183
184static void dbg_print_buf_chain(struct sk_buff *root_buf)
185{
186    if (DBG_OUTPUT != TIPC_NULL) {
187        struct sk_buff *buf = root_buf;
188
189        while (buf) {
190            msg_dbg(buf_msg(buf), "In chain: ");
191            buf = buf->next;
192        }
193    }
194}
195
196/*
197 * Simple link routines
198 */
199
200static unsigned int align(unsigned int i)
201{
202    return (i + 3) & ~3u;
203}
204
205static int link_working_working(struct link *l_ptr)
206{
207    return (l_ptr->state == WORKING_WORKING);
208}
209
210static int link_working_unknown(struct link *l_ptr)
211{
212    return (l_ptr->state == WORKING_UNKNOWN);
213}
214
215static int link_reset_unknown(struct link *l_ptr)
216{
217    return (l_ptr->state == RESET_UNKNOWN);
218}
219
220static int link_reset_reset(struct link *l_ptr)
221{
222    return (l_ptr->state == RESET_RESET);
223}
224
225static int link_blocked(struct link *l_ptr)
226{
227    return (l_ptr->exp_msg_count || l_ptr->blocked);
228}
229
230static int link_congested(struct link *l_ptr)
231{
232    return (l_ptr->out_queue_size >= l_ptr->queue_limit[0]);
233}
234
235static u32 link_max_pkt(struct link *l_ptr)
236{
237    return l_ptr->max_pkt;
238}
239
240static void link_init_max_pkt(struct link *l_ptr)
241{
242    u32 max_pkt;
243
244    max_pkt = (l_ptr->b_ptr->publ.mtu & ~3);
245    if (max_pkt > MAX_MSG_SIZE)
246        max_pkt = MAX_MSG_SIZE;
247
248    l_ptr->max_pkt_target = max_pkt;
249    if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
250        l_ptr->max_pkt = l_ptr->max_pkt_target;
251    else
252        l_ptr->max_pkt = MAX_PKT_DEFAULT;
253
254    l_ptr->max_pkt_probes = 0;
255}
256
257static u32 link_next_sent(struct link *l_ptr)
258{
259    if (l_ptr->next_out)
260        return msg_seqno(buf_msg(l_ptr->next_out));
261    return mod(l_ptr->next_out_no);
262}
263
264static u32 link_last_sent(struct link *l_ptr)
265{
266    return mod(link_next_sent(l_ptr) - 1);
267}
268
269/*
270 * Simple non-static link routines (i.e. referenced outside this file)
271 */
272
273int tipc_link_is_up(struct link *l_ptr)
274{
275    if (!l_ptr)
276        return 0;
277    return (link_working_working(l_ptr) || link_working_unknown(l_ptr));
278}
279
280int tipc_link_is_active(struct link *l_ptr)
281{
282    return ((l_ptr->owner->active_links[0] == l_ptr) ||
283        (l_ptr->owner->active_links[1] == l_ptr));
284}
285
286/**
287 * link_name_validate - validate & (optionally) deconstruct link name
288 * @name - ptr to link name string
289 * @name_parts - ptr to area for link name components (or NULL if not needed)
290 *
291 * Returns 1 if link name is valid, otherwise 0.
292 */
293
294static int link_name_validate(const char *name, struct link_name *name_parts)
295{
296    char name_copy[TIPC_MAX_LINK_NAME];
297    char *addr_local;
298    char *if_local;
299    char *addr_peer;
300    char *if_peer;
301    char dummy;
302    u32 z_local, c_local, n_local;
303    u32 z_peer, c_peer, n_peer;
304    u32 if_local_len;
305    u32 if_peer_len;
306
307    /* copy link name & ensure length is OK */
308
309    name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
310    /* need above in case non-Posix strncpy() doesn't pad with nulls */
311    strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
312    if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
313        return 0;
314
315    /* ensure all component parts of link name are present */
316
317    addr_local = name_copy;
318    if ((if_local = strchr(addr_local, ':')) == NULL)
319        return 0;
320    *(if_local++) = 0;
321    if ((addr_peer = strchr(if_local, '-')) == NULL)
322        return 0;
323    *(addr_peer++) = 0;
324    if_local_len = addr_peer - if_local;
325    if ((if_peer = strchr(addr_peer, ':')) == NULL)
326        return 0;
327    *(if_peer++) = 0;
328    if_peer_len = strlen(if_peer) + 1;
329
330    /* validate component parts of link name */
331
332    if ((sscanf(addr_local, "%u.%u.%u%c",
333            &z_local, &c_local, &n_local, &dummy) != 3) ||
334        (sscanf(addr_peer, "%u.%u.%u%c",
335            &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
336        (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
337        (z_peer > 255) || (c_peer > 4095) || (n_peer > 4095) ||
338        (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
339        (if_peer_len <= 1) || (if_peer_len > TIPC_MAX_IF_NAME) ||
340        (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
341        (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
342        return 0;
343
344    /* return link name components, if necessary */
345
346    if (name_parts) {
347        name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
348        strcpy(name_parts->if_local, if_local);
349        name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
350        strcpy(name_parts->if_peer, if_peer);
351    }
352    return 1;
353}
354
355/**
356 * link_timeout - handle expiration of link timer
357 * @l_ptr: pointer to link
358 *
359 * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
360 * with tipc_link_delete(). (There is no risk that the node will be deleted by
361 * another thread because tipc_link_delete() always cancels the link timer before
362 * tipc_node_delete() is called.)
363 */
364
365static void link_timeout(struct link *l_ptr)
366{
367    tipc_node_lock(l_ptr->owner);
368
369    /* update counters used in statistical profiling of send traffic */
370
371    l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
372    l_ptr->stats.queue_sz_counts++;
373
374    if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
375        l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
376
377    if (l_ptr->first_out) {
378        struct tipc_msg *msg = buf_msg(l_ptr->first_out);
379        u32 length = msg_size(msg);
380
381        if ((msg_user(msg) == MSG_FRAGMENTER)
382            && (msg_type(msg) == FIRST_FRAGMENT)) {
383            length = msg_size(msg_get_wrapped(msg));
384        }
385        if (length) {
386            l_ptr->stats.msg_lengths_total += length;
387            l_ptr->stats.msg_length_counts++;
388            if (length <= 64)
389                l_ptr->stats.msg_length_profile[0]++;
390            else if (length <= 256)
391                l_ptr->stats.msg_length_profile[1]++;
392            else if (length <= 1024)
393                l_ptr->stats.msg_length_profile[2]++;
394            else if (length <= 4096)
395                l_ptr->stats.msg_length_profile[3]++;
396            else if (length <= 16384)
397                l_ptr->stats.msg_length_profile[4]++;
398            else if (length <= 32768)
399                l_ptr->stats.msg_length_profile[5]++;
400            else
401                l_ptr->stats.msg_length_profile[6]++;
402        }
403    }
404
405    /* do all other link processing performed on a periodic basis */
406
407    link_check_defragm_bufs(l_ptr);
408
409    link_state_event(l_ptr, TIMEOUT_EVT);
410
411    if (l_ptr->next_out)
412        tipc_link_push_queue(l_ptr);
413
414    tipc_node_unlock(l_ptr->owner);
415}
416
417static void link_set_timer(struct link *l_ptr, u32 time)
418{
419    k_start_timer(&l_ptr->timer, time);
420}
421
422/**
423 * tipc_link_create - create a new link
424 * @b_ptr: pointer to associated bearer
425 * @peer: network address of node at other end of link
426 * @media_addr: media address to use when sending messages over link
427 *
428 * Returns pointer to link.
429 */
430
431struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer,
432                  const struct tipc_media_addr *media_addr)
433{
434    struct link *l_ptr;
435    struct tipc_msg *msg;
436    char *if_name;
437
438    l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
439    if (!l_ptr) {
440        warn("Link creation failed, no memory\n");
441        return NULL;
442    }
443
444    if (LINK_LOG_BUF_SIZE) {
445        char *pb = kmalloc(LINK_LOG_BUF_SIZE, GFP_ATOMIC);
446
447        if (!pb) {
448            kfree(l_ptr);
449            warn("Link creation failed, no memory for print buffer\n");
450            return NULL;
451        }
452        tipc_printbuf_init(&l_ptr->print_buf, pb, LINK_LOG_BUF_SIZE);
453    }
454
455    l_ptr->addr = peer;
456    if_name = strchr(b_ptr->publ.name, ':') + 1;
457    sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:",
458        tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
459        tipc_node(tipc_own_addr),
460        if_name,
461        tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
462        /* note: peer i/f is appended to link name by reset/activate */
463    memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
464    l_ptr->checkpoint = 1;
465    l_ptr->b_ptr = b_ptr;
466    link_set_supervision_props(l_ptr, b_ptr->media->tolerance);
467    l_ptr->state = RESET_UNKNOWN;
468
469    l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
470    msg = l_ptr->pmsg;
471    msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
472    msg_set_size(msg, sizeof(l_ptr->proto_msg));
473    msg_set_session(msg, (tipc_random & 0xffff));
474    msg_set_bearer_id(msg, b_ptr->identity);
475    strcpy((char *)msg_data(msg), if_name);
476
477    l_ptr->priority = b_ptr->priority;
478    tipc_link_set_queue_limits(l_ptr, b_ptr->media->window);
479
480    link_init_max_pkt(l_ptr);
481
482    l_ptr->next_out_no = 1;
483    INIT_LIST_HEAD(&l_ptr->waiting_ports);
484
485    link_reset_statistics(l_ptr);
486
487    l_ptr->owner = tipc_node_attach_link(l_ptr);
488    if (!l_ptr->owner) {
489        if (LINK_LOG_BUF_SIZE)
490            kfree(l_ptr->print_buf.buf);
491        kfree(l_ptr);
492        return NULL;
493    }
494
495    k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
496    list_add_tail(&l_ptr->link_list, &b_ptr->links);
497    tipc_k_signal((Handler)tipc_link_start, (unsigned long)l_ptr);
498
499    dbg("tipc_link_create(): tolerance = %u,cont intv = %u, abort_limit = %u\n",
500        l_ptr->tolerance, l_ptr->continuity_interval, l_ptr->abort_limit);
501
502    return l_ptr;
503}
504
505/**
506 * tipc_link_delete - delete a link
507 * @l_ptr: pointer to link
508 *
509 * Note: 'tipc_net_lock' is write_locked, bearer is locked.
510 * This routine must not grab the node lock until after link timer cancellation
511 * to avoid a potential deadlock situation.
512 */
513
514void tipc_link_delete(struct link *l_ptr)
515{
516    if (!l_ptr) {
517        err("Attempt to delete non-existent link\n");
518        return;
519    }
520
521    dbg("tipc_link_delete()\n");
522
523    k_cancel_timer(&l_ptr->timer);
524
525    tipc_node_lock(l_ptr->owner);
526    tipc_link_reset(l_ptr);
527    tipc_node_detach_link(l_ptr->owner, l_ptr);
528    tipc_link_stop(l_ptr);
529    list_del_init(&l_ptr->link_list);
530    if (LINK_LOG_BUF_SIZE)
531        kfree(l_ptr->print_buf.buf);
532    tipc_node_unlock(l_ptr->owner);
533    k_term_timer(&l_ptr->timer);
534    kfree(l_ptr);
535}
536
537void tipc_link_start(struct link *l_ptr)
538{
539    dbg("tipc_link_start %x\n", l_ptr);
540    link_state_event(l_ptr, STARTING_EVT);
541}
542
543/**
544 * link_schedule_port - schedule port for deferred sending
545 * @l_ptr: pointer to link
546 * @origport: reference to sending port
547 * @sz: amount of data to be sent
548 *
549 * Schedules port for renewed sending of messages after link congestion
550 * has abated.
551 */
552
553static int link_schedule_port(struct link *l_ptr, u32 origport, u32 sz)
554{
555    struct port *p_ptr;
556
557    spin_lock_bh(&tipc_port_list_lock);
558    p_ptr = tipc_port_lock(origport);
559    if (p_ptr) {
560        if (!p_ptr->wakeup)
561            goto exit;
562        if (!list_empty(&p_ptr->wait_list))
563            goto exit;
564        p_ptr->congested_link = l_ptr;
565        p_ptr->publ.congested = 1;
566        p_ptr->waiting_pkts = 1 + ((sz - 1) / link_max_pkt(l_ptr));
567        list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
568        l_ptr->stats.link_congs++;
569exit:
570        tipc_port_unlock(p_ptr);
571    }
572    spin_unlock_bh(&tipc_port_list_lock);
573    return -ELINKCONG;
574}
575
576void tipc_link_wakeup_ports(struct link *l_ptr, int all)
577{
578    struct port *p_ptr;
579    struct port *temp_p_ptr;
580    int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
581
582    if (all)
583        win = 100000;
584    if (win <= 0)
585        return;
586    if (!spin_trylock_bh(&tipc_port_list_lock))
587        return;
588    if (link_congested(l_ptr))
589        goto exit;
590    list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
591                 wait_list) {
592        if (win <= 0)
593            break;
594        list_del_init(&p_ptr->wait_list);
595        p_ptr->congested_link = NULL;
596        spin_lock_bh(p_ptr->publ.lock);
597        p_ptr->publ.congested = 0;
598        p_ptr->wakeup(&p_ptr->publ);
599        win -= p_ptr->waiting_pkts;
600        spin_unlock_bh(p_ptr->publ.lock);
601    }
602
603exit:
604    spin_unlock_bh(&tipc_port_list_lock);
605}
606
607/**
608 * link_release_outqueue - purge link's outbound message queue
609 * @l_ptr: pointer to link
610 */
611
612static void link_release_outqueue(struct link *l_ptr)
613{
614    struct sk_buff *buf = l_ptr->first_out;
615    struct sk_buff *next;
616
617    while (buf) {
618        next = buf->next;
619        buf_discard(buf);
620        buf = next;
621    }
622    l_ptr->first_out = NULL;
623    l_ptr->out_queue_size = 0;
624}
625
626/**
627 * tipc_link_reset_fragments - purge link's inbound message fragments queue
628 * @l_ptr: pointer to link
629 */
630
631void tipc_link_reset_fragments(struct link *l_ptr)
632{
633    struct sk_buff *buf = l_ptr->defragm_buf;
634    struct sk_buff *next;
635
636    while (buf) {
637        next = buf->next;
638        buf_discard(buf);
639        buf = next;
640    }
641    l_ptr->defragm_buf = NULL;
642}
643
644/**
645 * tipc_link_stop - purge all inbound and outbound messages associated with link
646 * @l_ptr: pointer to link
647 */
648
649void tipc_link_stop(struct link *l_ptr)
650{
651    struct sk_buff *buf;
652    struct sk_buff *next;
653
654    buf = l_ptr->oldest_deferred_in;
655    while (buf) {
656        next = buf->next;
657        buf_discard(buf);
658        buf = next;
659    }
660
661    buf = l_ptr->first_out;
662    while (buf) {
663        next = buf->next;
664        buf_discard(buf);
665        buf = next;
666    }
667
668    tipc_link_reset_fragments(l_ptr);
669
670    buf_discard(l_ptr->proto_msg_queue);
671    l_ptr->proto_msg_queue = NULL;
672}
673
674#if 0
675
676/* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
677
678static void link_recv_event(struct link_event *ev)
679{
680    ev->fcn(ev->addr, ev->name, ev->up);
681    kfree(ev);
682}
683
684static void link_send_event(void (*fcn)(u32 a, char *n, int up),
685                struct link *l_ptr, int up)
686{
687    struct link_event *ev;
688
689    ev = kmalloc(sizeof(*ev), GFP_ATOMIC);
690    if (!ev) {
691        warn("Link event allocation failure\n");
692        return;
693    }
694    ev->addr = l_ptr->addr;
695    ev->up = up;
696    ev->fcn = fcn;
697    memcpy(ev->name, l_ptr->name, TIPC_MAX_LINK_NAME);
698    tipc_k_signal((Handler)link_recv_event, (unsigned long)ev);
699}
700
701#else
702
703#define link_send_event(fcn, l_ptr, up) do { } while (0)
704
705#endif
706
707void tipc_link_reset(struct link *l_ptr)
708{
709    struct sk_buff *buf;
710    u32 prev_state = l_ptr->state;
711    u32 checkpoint = l_ptr->next_in_no;
712    int was_active_link = tipc_link_is_active(l_ptr);
713
714    msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
715
716    /* Link is down, accept any session */
717    l_ptr->peer_session = INVALID_SESSION;
718
719    /* Prepare for max packet size negotiation */
720    link_init_max_pkt(l_ptr);
721
722    l_ptr->state = RESET_UNKNOWN;
723    dbg_link_state("Resetting Link\n");
724
725    if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
726        return;
727
728    tipc_node_link_down(l_ptr->owner, l_ptr);
729    tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
730#if 0
731    tipc_printf(TIPC_CONS, "\nReset link <%s>\n", l_ptr->name);
732    dbg_link_dump();
733#endif
734    if (was_active_link && tipc_node_has_active_links(l_ptr->owner) &&
735        l_ptr->owner->permit_changeover) {
736        l_ptr->reset_checkpoint = checkpoint;
737        l_ptr->exp_msg_count = START_CHANGEOVER;
738    }
739
740    /* Clean up all queues: */
741
742    link_release_outqueue(l_ptr);
743    buf_discard(l_ptr->proto_msg_queue);
744    l_ptr->proto_msg_queue = NULL;
745    buf = l_ptr->oldest_deferred_in;
746    while (buf) {
747        struct sk_buff *next = buf->next;
748        buf_discard(buf);
749        buf = next;
750    }
751    if (!list_empty(&l_ptr->waiting_ports))
752        tipc_link_wakeup_ports(l_ptr, 1);
753
754    l_ptr->retransm_queue_head = 0;
755    l_ptr->retransm_queue_size = 0;
756    l_ptr->last_out = NULL;
757    l_ptr->first_out = NULL;
758    l_ptr->next_out = NULL;
759    l_ptr->unacked_window = 0;
760    l_ptr->checkpoint = 1;
761    l_ptr->next_out_no = 1;
762    l_ptr->deferred_inqueue_sz = 0;
763    l_ptr->oldest_deferred_in = NULL;
764    l_ptr->newest_deferred_in = NULL;
765    l_ptr->fsm_msg_cnt = 0;
766    l_ptr->stale_count = 0;
767    link_reset_statistics(l_ptr);
768
769    link_send_event(tipc_cfg_link_event, l_ptr, 0);
770    if (!in_own_cluster(l_ptr->addr))
771        link_send_event(tipc_disc_link_event, l_ptr, 0);
772}
773
774
775static void link_activate(struct link *l_ptr)
776{
777    l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
778    tipc_node_link_up(l_ptr->owner, l_ptr);
779    tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
780    link_send_event(tipc_cfg_link_event, l_ptr, 1);
781    if (!in_own_cluster(l_ptr->addr))
782        link_send_event(tipc_disc_link_event, l_ptr, 1);
783}
784
785/**
786 * link_state_event - link finite state machine
787 * @l_ptr: pointer to link
788 * @event: state machine event to process
789 */
790
791static void link_state_event(struct link *l_ptr, unsigned event)
792{
793    struct link *other;
794    u32 cont_intv = l_ptr->continuity_interval;
795
796    if (!l_ptr->started && (event != STARTING_EVT))
797        return; /* Not yet. */
798
799    if (link_blocked(l_ptr)) {
800        if (event == TIMEOUT_EVT) {
801            link_set_timer(l_ptr, cont_intv);
802        }
803        return; /* Changeover going on */
804    }
805    dbg_link("STATE_EV: <%s> ", l_ptr->name);
806
807    switch (l_ptr->state) {
808    case WORKING_WORKING:
809        dbg_link("WW/");
810        switch (event) {
811        case TRAFFIC_MSG_EVT:
812            dbg_link("TRF-");
813            /* fall through */
814        case ACTIVATE_MSG:
815            dbg_link("ACT\n");
816            break;
817        case TIMEOUT_EVT:
818            dbg_link("TIM ");
819            if (l_ptr->next_in_no != l_ptr->checkpoint) {
820                l_ptr->checkpoint = l_ptr->next_in_no;
821                if (tipc_bclink_acks_missing(l_ptr->owner)) {
822                    tipc_link_send_proto_msg(l_ptr, STATE_MSG,
823                                 0, 0, 0, 0, 0);
824                    l_ptr->fsm_msg_cnt++;
825                } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
826                    tipc_link_send_proto_msg(l_ptr, STATE_MSG,
827                                 1, 0, 0, 0, 0);
828                    l_ptr->fsm_msg_cnt++;
829                }
830                link_set_timer(l_ptr, cont_intv);
831                break;
832            }
833            dbg_link(" -> WU\n");
834            l_ptr->state = WORKING_UNKNOWN;
835            l_ptr->fsm_msg_cnt = 0;
836            tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
837            l_ptr->fsm_msg_cnt++;
838            link_set_timer(l_ptr, cont_intv / 4);
839            break;
840        case RESET_MSG:
841            dbg_link("RES -> RR\n");
842            info("Resetting link <%s>, requested by peer\n",
843                 l_ptr->name);
844            tipc_link_reset(l_ptr);
845            l_ptr->state = RESET_RESET;
846            l_ptr->fsm_msg_cnt = 0;
847            tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
848            l_ptr->fsm_msg_cnt++;
849            link_set_timer(l_ptr, cont_intv);
850            break;
851        default:
852            err("Unknown link event %u in WW state\n", event);
853        }
854        break;
855    case WORKING_UNKNOWN:
856        dbg_link("WU/");
857        switch (event) {
858        case TRAFFIC_MSG_EVT:
859            dbg_link("TRF-");
860        case ACTIVATE_MSG:
861            dbg_link("ACT -> WW\n");
862            l_ptr->state = WORKING_WORKING;
863            l_ptr->fsm_msg_cnt = 0;
864            link_set_timer(l_ptr, cont_intv);
865            break;
866        case RESET_MSG:
867            dbg_link("RES -> RR\n");
868            info("Resetting link <%s>, requested by peer "
869                 "while probing\n", l_ptr->name);
870            tipc_link_reset(l_ptr);
871            l_ptr->state = RESET_RESET;
872            l_ptr->fsm_msg_cnt = 0;
873            tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
874            l_ptr->fsm_msg_cnt++;
875            link_set_timer(l_ptr, cont_intv);
876            break;
877        case TIMEOUT_EVT:
878            dbg_link("TIM ");
879            if (l_ptr->next_in_no != l_ptr->checkpoint) {
880                dbg_link("-> WW \n");
881                l_ptr->state = WORKING_WORKING;
882                l_ptr->fsm_msg_cnt = 0;
883                l_ptr->checkpoint = l_ptr->next_in_no;
884                if (tipc_bclink_acks_missing(l_ptr->owner)) {
885                    tipc_link_send_proto_msg(l_ptr, STATE_MSG,
886                                 0, 0, 0, 0, 0);
887                    l_ptr->fsm_msg_cnt++;
888                }
889                link_set_timer(l_ptr, cont_intv);
890            } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
891                dbg_link("Probing %u/%u,timer = %u ms)\n",
892                     l_ptr->fsm_msg_cnt, l_ptr->abort_limit,
893                     cont_intv / 4);
894                tipc_link_send_proto_msg(l_ptr, STATE_MSG,
895                             1, 0, 0, 0, 0);
896                l_ptr->fsm_msg_cnt++;
897                link_set_timer(l_ptr, cont_intv / 4);
898            } else { /* Link has failed */
899                dbg_link("-> RU (%u probes unanswered)\n",
900                     l_ptr->fsm_msg_cnt);
901                warn("Resetting link <%s>, peer not responding\n",
902                     l_ptr->name);
903                tipc_link_reset(l_ptr);
904                l_ptr->state = RESET_UNKNOWN;
905                l_ptr->fsm_msg_cnt = 0;
906                tipc_link_send_proto_msg(l_ptr, RESET_MSG,
907                             0, 0, 0, 0, 0);
908                l_ptr->fsm_msg_cnt++;
909                link_set_timer(l_ptr, cont_intv);
910            }
911            break;
912        default:
913            err("Unknown link event %u in WU state\n", event);
914        }
915        break;
916    case RESET_UNKNOWN:
917        dbg_link("RU/");
918        switch (event) {
919        case TRAFFIC_MSG_EVT:
920            dbg_link("TRF-\n");
921            break;
922        case ACTIVATE_MSG:
923            other = l_ptr->owner->active_links[0];
924            if (other && link_working_unknown(other)) {
925                dbg_link("ACT\n");
926                break;
927            }
928            dbg_link("ACT -> WW\n");
929            l_ptr->state = WORKING_WORKING;
930            l_ptr->fsm_msg_cnt = 0;
931            link_activate(l_ptr);
932            tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
933            l_ptr->fsm_msg_cnt++;
934            link_set_timer(l_ptr, cont_intv);
935            break;
936        case RESET_MSG:
937            dbg_link("RES \n");
938            dbg_link(" -> RR\n");
939            l_ptr->state = RESET_RESET;
940            l_ptr->fsm_msg_cnt = 0;
941            tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
942            l_ptr->fsm_msg_cnt++;
943            link_set_timer(l_ptr, cont_intv);
944            break;
945        case STARTING_EVT:
946            dbg_link("START-");
947            l_ptr->started = 1;
948            /* fall through */
949        case TIMEOUT_EVT:
950            dbg_link("TIM \n");
951            tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
952            l_ptr->fsm_msg_cnt++;
953            link_set_timer(l_ptr, cont_intv);
954            break;
955        default:
956            err("Unknown link event %u in RU state\n", event);
957        }
958        break;
959    case RESET_RESET:
960        dbg_link("RR/ ");
961        switch (event) {
962        case TRAFFIC_MSG_EVT:
963            dbg_link("TRF-");
964            /* fall through */
965        case ACTIVATE_MSG:
966            other = l_ptr->owner->active_links[0];
967            if (other && link_working_unknown(other)) {
968                dbg_link("ACT\n");
969                break;
970            }
971            dbg_link("ACT -> WW\n");
972            l_ptr->state = WORKING_WORKING;
973            l_ptr->fsm_msg_cnt = 0;
974            link_activate(l_ptr);
975            tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
976            l_ptr->fsm_msg_cnt++;
977            link_set_timer(l_ptr, cont_intv);
978            break;
979        case RESET_MSG:
980            dbg_link("RES\n");
981            break;
982        case TIMEOUT_EVT:
983            dbg_link("TIM\n");
984            tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
985            l_ptr->fsm_msg_cnt++;
986            link_set_timer(l_ptr, cont_intv);
987            dbg_link("fsm_msg_cnt %u\n", l_ptr->fsm_msg_cnt);
988            break;
989        default:
990            err("Unknown link event %u in RR state\n", event);
991        }
992        break;
993    default:
994        err("Unknown link state %u/%u\n", l_ptr->state, event);
995    }
996}
997
998/*
999 * link_bundle_buf(): Append contents of a buffer to
1000 * the tail of an existing one.
1001 */
1002
1003static int link_bundle_buf(struct link *l_ptr,
1004               struct sk_buff *bundler,
1005               struct sk_buff *buf)
1006{
1007    struct tipc_msg *bundler_msg = buf_msg(bundler);
1008    struct tipc_msg *msg = buf_msg(buf);
1009    u32 size = msg_size(msg);
1010    u32 bundle_size = msg_size(bundler_msg);
1011    u32 to_pos = align(bundle_size);
1012    u32 pad = to_pos - bundle_size;
1013
1014    if (msg_user(bundler_msg) != MSG_BUNDLER)
1015        return 0;
1016    if (msg_type(bundler_msg) != OPEN_MSG)
1017        return 0;
1018    if (skb_tailroom(bundler) < (pad + size))
1019        return 0;
1020    if (link_max_pkt(l_ptr) < (to_pos + size))
1021        return 0;
1022
1023    skb_put(bundler, pad + size);
1024    skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
1025    msg_set_size(bundler_msg, to_pos + size);
1026    msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
1027    dbg("Packed msg # %u(%u octets) into pos %u in buf(#%u)\n",
1028        msg_msgcnt(bundler_msg), size, to_pos, msg_seqno(bundler_msg));
1029    msg_dbg(msg, "PACKD:");
1030    buf_discard(buf);
1031    l_ptr->stats.sent_bundled++;
1032    return 1;
1033}
1034
1035static void link_add_to_outqueue(struct link *l_ptr,
1036                 struct sk_buff *buf,
1037                 struct tipc_msg *msg)
1038{
1039    u32 ack = mod(l_ptr->next_in_no - 1);
1040    u32 seqno = mod(l_ptr->next_out_no++);
1041
1042    msg_set_word(msg, 2, ((ack << 16) | seqno));
1043    msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1044    buf->next = NULL;
1045    if (l_ptr->first_out) {
1046        l_ptr->last_out->next = buf;
1047        l_ptr->last_out = buf;
1048    } else
1049        l_ptr->first_out = l_ptr->last_out = buf;
1050    l_ptr->out_queue_size++;
1051}
1052
1053/*
1054 * tipc_link_send_buf() is the 'full path' for messages, called from
1055 * inside TIPC when the 'fast path' in tipc_send_buf
1056 * has failed, and from link_send()
1057 */
1058
1059int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf)
1060{
1061    struct tipc_msg *msg = buf_msg(buf);
1062    u32 size = msg_size(msg);
1063    u32 dsz = msg_data_sz(msg);
1064    u32 queue_size = l_ptr->out_queue_size;
1065    u32 imp = msg_tot_importance(msg);
1066    u32 queue_limit = l_ptr->queue_limit[imp];
1067    u32 max_packet = link_max_pkt(l_ptr);
1068
1069    msg_set_prevnode(msg, tipc_own_addr); /* If routed message */
1070
1071    /* Match msg importance against queue limits: */
1072
1073    if (unlikely(queue_size >= queue_limit)) {
1074        if (imp <= TIPC_CRITICAL_IMPORTANCE) {
1075            return link_schedule_port(l_ptr, msg_origport(msg),
1076                          size);
1077        }
1078        msg_dbg(msg, "TIPC: Congestion, throwing away\n");
1079        buf_discard(buf);
1080        if (imp > CONN_MANAGER) {
1081            warn("Resetting link <%s>, send queue full", l_ptr->name);
1082            tipc_link_reset(l_ptr);
1083        }
1084        return dsz;
1085    }
1086
1087    /* Fragmentation needed ? */
1088
1089    if (size > max_packet)
1090        return tipc_link_send_long_buf(l_ptr, buf);
1091
1092    /* Packet can be queued or sent: */
1093
1094    if (queue_size > l_ptr->stats.max_queue_sz)
1095        l_ptr->stats.max_queue_sz = queue_size;
1096
1097    if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
1098           !link_congested(l_ptr))) {
1099        link_add_to_outqueue(l_ptr, buf, msg);
1100
1101        if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
1102            l_ptr->unacked_window = 0;
1103        } else {
1104            tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1105            l_ptr->stats.bearer_congs++;
1106            l_ptr->next_out = buf;
1107        }
1108        return dsz;
1109    }
1110    /* Congestion: can message be bundled ?: */
1111
1112    if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
1113        (msg_user(msg) != MSG_FRAGMENTER)) {
1114
1115        /* Try adding message to an existing bundle */
1116
1117        if (l_ptr->next_out &&
1118            link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
1119            tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
1120            return dsz;
1121        }
1122
1123        /* Try creating a new bundle */
1124
1125        if (size <= max_packet * 2 / 3) {
1126            struct sk_buff *bundler = buf_acquire(max_packet);
1127            struct tipc_msg bundler_hdr;
1128
1129            if (bundler) {
1130                msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
1131                     INT_H_SIZE, l_ptr->addr);
1132                skb_copy_to_linear_data(bundler, &bundler_hdr,
1133                            INT_H_SIZE);
1134                skb_trim(bundler, INT_H_SIZE);
1135                link_bundle_buf(l_ptr, bundler, buf);
1136                buf = bundler;
1137                msg = buf_msg(buf);
1138                l_ptr->stats.sent_bundles++;
1139            }
1140        }
1141    }
1142    if (!l_ptr->next_out)
1143        l_ptr->next_out = buf;
1144    link_add_to_outqueue(l_ptr, buf, msg);
1145    tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
1146    return dsz;
1147}
1148
1149/*
1150 * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
1151 * not been selected yet, and the the owner node is not locked
1152 * Called by TIPC internal users, e.g. the name distributor
1153 */
1154
1155int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
1156{
1157    struct link *l_ptr;
1158    struct tipc_node *n_ptr;
1159    int res = -ELINKCONG;
1160
1161    read_lock_bh(&tipc_net_lock);
1162    n_ptr = tipc_node_select(dest, selector);
1163    if (n_ptr) {
1164        tipc_node_lock(n_ptr);
1165        l_ptr = n_ptr->active_links[selector & 1];
1166        if (l_ptr) {
1167            dbg("tipc_link_send: found link %x for dest %x\n", l_ptr, dest);
1168            res = tipc_link_send_buf(l_ptr, buf);
1169        } else {
1170            dbg("Attempt to send msg to unreachable node:\n");
1171            msg_dbg(buf_msg(buf),">>>");
1172            buf_discard(buf);
1173        }
1174        tipc_node_unlock(n_ptr);
1175    } else {
1176        dbg("Attempt to send msg to unknown node:\n");
1177        msg_dbg(buf_msg(buf),">>>");
1178        buf_discard(buf);
1179    }
1180    read_unlock_bh(&tipc_net_lock);
1181    return res;
1182}
1183
1184/*
1185 * link_send_buf_fast: Entry for data messages where the
1186 * destination link is known and the header is complete,
1187 * inclusive total message length. Very time critical.
1188 * Link is locked. Returns user data length.
1189 */
1190
1191static int link_send_buf_fast(struct link *l_ptr, struct sk_buff *buf,
1192                  u32 *used_max_pkt)
1193{
1194    struct tipc_msg *msg = buf_msg(buf);
1195    int res = msg_data_sz(msg);
1196
1197    if (likely(!link_congested(l_ptr))) {
1198        if (likely(msg_size(msg) <= link_max_pkt(l_ptr))) {
1199            if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
1200                link_add_to_outqueue(l_ptr, buf, msg);
1201                if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
1202                                &l_ptr->media_addr))) {
1203                    l_ptr->unacked_window = 0;
1204                    msg_dbg(msg,"SENT_FAST:");
1205                    return res;
1206                }
1207                dbg("failed sent fast...\n");
1208                tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1209                l_ptr->stats.bearer_congs++;
1210                l_ptr->next_out = buf;
1211                return res;
1212            }
1213        }
1214        else
1215            *used_max_pkt = link_max_pkt(l_ptr);
1216    }
1217    return tipc_link_send_buf(l_ptr, buf); /* All other cases */
1218}
1219
1220/*
1221 * tipc_send_buf_fast: Entry for data messages where the
1222 * destination node is known and the header is complete,
1223 * inclusive total message length.
1224 * Returns user data length.
1225 */
1226int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
1227{
1228    struct link *l_ptr;
1229    struct tipc_node *n_ptr;
1230    int res;
1231    u32 selector = msg_origport(buf_msg(buf)) & 1;
1232    u32 dummy;
1233
1234    if (destnode == tipc_own_addr)
1235        return tipc_port_recv_msg(buf);
1236
1237    read_lock_bh(&tipc_net_lock);
1238    n_ptr = tipc_node_select(destnode, selector);
1239    if (likely(n_ptr)) {
1240        tipc_node_lock(n_ptr);
1241        l_ptr = n_ptr->active_links[selector];
1242        dbg("send_fast: buf %x selected %x, destnode = %x\n",
1243            buf, l_ptr, destnode);
1244        if (likely(l_ptr)) {
1245            res = link_send_buf_fast(l_ptr, buf, &dummy);
1246            tipc_node_unlock(n_ptr);
1247            read_unlock_bh(&tipc_net_lock);
1248            return res;
1249        }
1250        tipc_node_unlock(n_ptr);
1251    }
1252    read_unlock_bh(&tipc_net_lock);
1253    res = msg_data_sz(buf_msg(buf));
1254    tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1255    return res;
1256}
1257
1258
1259/*
1260 * tipc_link_send_sections_fast: Entry for messages where the
1261 * destination processor is known and the header is complete,
1262 * except for total message length.
1263 * Returns user data length or errno.
1264 */
1265int tipc_link_send_sections_fast(struct port *sender,
1266                 struct iovec const *msg_sect,
1267                 const u32 num_sect,
1268                 u32 destaddr)
1269{
1270    struct tipc_msg *hdr = &sender->publ.phdr;
1271    struct link *l_ptr;
1272    struct sk_buff *buf;
1273    struct tipc_node *node;
1274    int res;
1275    u32 selector = msg_origport(hdr) & 1;
1276
1277again:
1278    /*
1279     * Try building message using port's max_pkt hint.
1280     * (Must not hold any locks while building message.)
1281     */
1282
1283    res = msg_build(hdr, msg_sect, num_sect, sender->publ.max_pkt,
1284            !sender->user_port, &buf);
1285
1286    read_lock_bh(&tipc_net_lock);
1287    node = tipc_node_select(destaddr, selector);
1288    if (likely(node)) {
1289        tipc_node_lock(node);
1290        l_ptr = node->active_links[selector];
1291        if (likely(l_ptr)) {
1292            if (likely(buf)) {
1293                res = link_send_buf_fast(l_ptr, buf,
1294                             &sender->publ.max_pkt);
1295                if (unlikely(res < 0))
1296                    buf_discard(buf);
1297exit:
1298                tipc_node_unlock(node);
1299                read_unlock_bh(&tipc_net_lock);
1300                return res;
1301            }
1302
1303            /* Exit if build request was invalid */
1304
1305            if (unlikely(res < 0))
1306                goto exit;
1307
1308            /* Exit if link (or bearer) is congested */
1309
1310            if (link_congested(l_ptr) ||
1311                !list_empty(&l_ptr->b_ptr->cong_links)) {
1312                res = link_schedule_port(l_ptr,
1313                             sender->publ.ref, res);
1314                goto exit;
1315            }
1316
1317            /*
1318             * Message size exceeds max_pkt hint; update hint,
1319             * then re-try fast path or fragment the message
1320             */
1321
1322            sender->publ.max_pkt = link_max_pkt(l_ptr);
1323            tipc_node_unlock(node);
1324            read_unlock_bh(&tipc_net_lock);
1325
1326
1327            if ((msg_hdr_sz(hdr) + res) <= sender->publ.max_pkt)
1328                goto again;
1329
1330            return link_send_sections_long(sender, msg_sect,
1331                               num_sect, destaddr);
1332        }
1333        tipc_node_unlock(node);
1334    }
1335    read_unlock_bh(&tipc_net_lock);
1336
1337    /* Couldn't find a link to the destination node */
1338
1339    if (buf)
1340        return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1341    if (res >= 0)
1342        return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1343                         TIPC_ERR_NO_NODE);
1344    return res;
1345}
1346
1347/*
1348 * link_send_sections_long(): Entry for long messages where the
1349 * destination node is known and the header is complete,
1350 * inclusive total message length.
1351 * Link and bearer congestion status have been checked to be ok,
1352 * and are ignored if they change.
1353 *
1354 * Note that fragments do not use the full link MTU so that they won't have
1355 * to undergo refragmentation if link changeover causes them to be sent
1356 * over another link with an additional tunnel header added as prefix.
1357 * (Refragmentation will still occur if the other link has a smaller MTU.)
1358 *
1359 * Returns user data length or errno.
1360 */
1361static int link_send_sections_long(struct port *sender,
1362                   struct iovec const *msg_sect,
1363                   u32 num_sect,
1364                   u32 destaddr)
1365{
1366    struct link *l_ptr;
1367    struct tipc_node *node;
1368    struct tipc_msg *hdr = &sender->publ.phdr;
1369    u32 dsz = msg_data_sz(hdr);
1370    u32 max_pkt,fragm_sz,rest;
1371    struct tipc_msg fragm_hdr;
1372    struct sk_buff *buf,*buf_chain,*prev;
1373    u32 fragm_crs,fragm_rest,hsz,sect_rest;
1374    const unchar *sect_crs;
1375    int curr_sect;
1376    u32 fragm_no;
1377
1378again:
1379    fragm_no = 1;
1380    max_pkt = sender->publ.max_pkt - INT_H_SIZE;
1381        /* leave room for tunnel header in case of link changeover */
1382    fragm_sz = max_pkt - INT_H_SIZE;
1383        /* leave room for fragmentation header in each fragment */
1384    rest = dsz;
1385    fragm_crs = 0;
1386    fragm_rest = 0;
1387    sect_rest = 0;
1388    sect_crs = NULL;
1389    curr_sect = -1;
1390
1391    /* Prepare reusable fragment header: */
1392
1393    msg_dbg(hdr, ">FRAGMENTING>");
1394    msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1395         INT_H_SIZE, msg_destnode(hdr));
1396    msg_set_link_selector(&fragm_hdr, sender->publ.ref);
1397    msg_set_size(&fragm_hdr, max_pkt);
1398    msg_set_fragm_no(&fragm_hdr, 1);
1399
1400    /* Prepare header of first fragment: */
1401
1402    buf_chain = buf = buf_acquire(max_pkt);
1403    if (!buf)
1404        return -ENOMEM;
1405    buf->next = NULL;
1406    skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1407    hsz = msg_hdr_sz(hdr);
1408    skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1409    msg_dbg(buf_msg(buf), ">BUILD>");
1410
1411    /* Chop up message: */
1412
1413    fragm_crs = INT_H_SIZE + hsz;
1414    fragm_rest = fragm_sz - hsz;
1415
1416    do { /* For all sections */
1417        u32 sz;
1418
1419        if (!sect_rest) {
1420            sect_rest = msg_sect[++curr_sect].iov_len;
1421            sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
1422        }
1423
1424        if (sect_rest < fragm_rest)
1425            sz = sect_rest;
1426        else
1427            sz = fragm_rest;
1428
1429        if (likely(!sender->user_port)) {
1430            if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1431error:
1432                for (; buf_chain; buf_chain = buf) {
1433                    buf = buf_chain->next;
1434                    buf_discard(buf_chain);
1435                }
1436                return -EFAULT;
1437            }
1438        } else
1439            skb_copy_to_linear_data_offset(buf, fragm_crs,
1440                               sect_crs, sz);
1441        sect_crs += sz;
1442        sect_rest -= sz;
1443        fragm_crs += sz;
1444        fragm_rest -= sz;
1445        rest -= sz;
1446
1447        if (!fragm_rest && rest) {
1448
1449            /* Initiate new fragment: */
1450            if (rest <= fragm_sz) {
1451                fragm_sz = rest;
1452                msg_set_type(&fragm_hdr,LAST_FRAGMENT);
1453            } else {
1454                msg_set_type(&fragm_hdr, FRAGMENT);
1455            }
1456            msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1457            msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1458            prev = buf;
1459            buf = buf_acquire(fragm_sz + INT_H_SIZE);
1460            if (!buf)
1461                goto error;
1462
1463            buf->next = NULL;
1464            prev->next = buf;
1465            skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1466            fragm_crs = INT_H_SIZE;
1467            fragm_rest = fragm_sz;
1468            msg_dbg(buf_msg(buf)," >BUILD>");
1469        }
1470    }
1471    while (rest > 0);
1472
1473    /*
1474     * Now we have a buffer chain. Select a link and check
1475     * that packet size is still OK
1476     */
1477    node = tipc_node_select(destaddr, sender->publ.ref & 1);
1478    if (likely(node)) {
1479        tipc_node_lock(node);
1480        l_ptr = node->active_links[sender->publ.ref & 1];
1481        if (!l_ptr) {
1482            tipc_node_unlock(node);
1483            goto reject;
1484        }
1485        if (link_max_pkt(l_ptr) < max_pkt) {
1486            sender->publ.max_pkt = link_max_pkt(l_ptr);
1487            tipc_node_unlock(node);
1488            for (; buf_chain; buf_chain = buf) {
1489                buf = buf_chain->next;
1490                buf_discard(buf_chain);
1491            }
1492            goto again;
1493        }
1494    } else {
1495reject:
1496        for (; buf_chain; buf_chain = buf) {
1497            buf = buf_chain->next;
1498            buf_discard(buf_chain);
1499        }
1500        return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1501                         TIPC_ERR_NO_NODE);
1502    }
1503
1504    /* Append whole chain to send queue: */
1505
1506    buf = buf_chain;
1507    l_ptr->long_msg_seq_no = mod(l_ptr->long_msg_seq_no + 1);
1508    if (!l_ptr->next_out)
1509        l_ptr->next_out = buf_chain;
1510    l_ptr->stats.sent_fragmented++;
1511    while (buf) {
1512        struct sk_buff *next = buf->next;
1513        struct tipc_msg *msg = buf_msg(buf);
1514
1515        l_ptr->stats.sent_fragments++;
1516        msg_set_long_msgno(msg, l_ptr->long_msg_seq_no);
1517        link_add_to_outqueue(l_ptr, buf, msg);
1518        msg_dbg(msg, ">ADD>");
1519        buf = next;
1520    }
1521
1522    /* Send it, if possible: */
1523
1524    tipc_link_push_queue(l_ptr);
1525    tipc_node_unlock(node);
1526    return dsz;
1527}
1528
1529/*
1530 * tipc_link_push_packet: Push one unsent packet to the media
1531 */
1532u32 tipc_link_push_packet(struct link *l_ptr)
1533{
1534    struct sk_buff *buf = l_ptr->first_out;
1535    u32 r_q_size = l_ptr->retransm_queue_size;
1536    u32 r_q_head = l_ptr->retransm_queue_head;
1537
1538    /* Step to position where retransmission failed, if any, */
1539    /* consider that buffers may have been released in meantime */
1540
1541    if (r_q_size && buf) {
1542        u32 last = lesser(mod(r_q_head + r_q_size),
1543                  link_last_sent(l_ptr));
1544        u32 first = msg_seqno(buf_msg(buf));
1545
1546        while (buf && less(first, r_q_head)) {
1547            first = mod(first + 1);
1548            buf = buf->next;
1549        }
1550        l_ptr->retransm_queue_head = r_q_head = first;
1551        l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1552    }
1553
1554    /* Continue retransmission now, if there is anything: */
1555
1556    if (r_q_size && buf && !skb_cloned(buf)) {
1557        msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1558        msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1559        if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1560            msg_dbg(buf_msg(buf), ">DEF-RETR>");
1561            l_ptr->retransm_queue_head = mod(++r_q_head);
1562            l_ptr->retransm_queue_size = --r_q_size;
1563            l_ptr->stats.retransmitted++;
1564            return 0;
1565        } else {
1566            l_ptr->stats.bearer_congs++;
1567            msg_dbg(buf_msg(buf), "|>DEF-RETR>");
1568            return PUSH_FAILED;
1569        }
1570    }
1571
1572    /* Send deferred protocol message, if any: */
1573
1574    buf = l_ptr->proto_msg_queue;
1575    if (buf) {
1576        msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1577        msg_set_bcast_ack(buf_msg(buf),l_ptr->owner->bclink.last_in);
1578        if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1579            msg_dbg(buf_msg(buf), ">DEF-PROT>");
1580            l_ptr->unacked_window = 0;
1581            buf_discard(buf);
1582            l_ptr->proto_msg_queue = NULL;
1583            return 0;
1584        } else {
1585            msg_dbg(buf_msg(buf), "|>DEF-PROT>");
1586            l_ptr->stats.bearer_congs++;
1587            return PUSH_FAILED;
1588        }
1589    }
1590
1591    /* Send one deferred data message, if send window not full: */
1592
1593    buf = l_ptr->next_out;
1594    if (buf) {
1595        struct tipc_msg *msg = buf_msg(buf);
1596        u32 next = msg_seqno(msg);
1597        u32 first = msg_seqno(buf_msg(l_ptr->first_out));
1598
1599        if (mod(next - first) < l_ptr->queue_limit[0]) {
1600            msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1601            msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1602            if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1603                if (msg_user(msg) == MSG_BUNDLER)
1604                    msg_set_type(msg, CLOSED_MSG);
1605                msg_dbg(msg, ">PUSH-DATA>");
1606                l_ptr->next_out = buf->next;
1607                return 0;
1608            } else {
1609                msg_dbg(msg, "|PUSH-DATA|");
1610                l_ptr->stats.bearer_congs++;
1611                return PUSH_FAILED;
1612            }
1613        }
1614    }
1615    return PUSH_FINISHED;
1616}
1617
1618/*
1619 * push_queue(): push out the unsent messages of a link where
1620 * congestion has abated. Node is locked
1621 */
1622void tipc_link_push_queue(struct link *l_ptr)
1623{
1624    u32 res;
1625
1626    if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
1627        return;
1628
1629    do {
1630        res = tipc_link_push_packet(l_ptr);
1631    } while (!res);
1632
1633    if (res == PUSH_FAILED)
1634        tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1635}
1636
1637static void link_reset_all(unsigned long addr)
1638{
1639    struct tipc_node *n_ptr;
1640    char addr_string[16];
1641    u32 i;
1642
1643    read_lock_bh(&tipc_net_lock);
1644    n_ptr = tipc_node_find((u32)addr);
1645    if (!n_ptr) {
1646        read_unlock_bh(&tipc_net_lock);
1647        return; /* node no longer exists */
1648    }
1649
1650    tipc_node_lock(n_ptr);
1651
1652    warn("Resetting all links to %s\n",
1653         addr_string_fill(addr_string, n_ptr->addr));
1654
1655    for (i = 0; i < MAX_BEARERS; i++) {
1656        if (n_ptr->links[i]) {
1657            link_print(n_ptr->links[i], TIPC_OUTPUT,
1658                   "Resetting link\n");
1659            tipc_link_reset(n_ptr->links[i]);
1660        }
1661    }
1662
1663    tipc_node_unlock(n_ptr);
1664    read_unlock_bh(&tipc_net_lock);
1665}
1666
1667static void link_retransmit_failure(struct link *l_ptr, struct sk_buff *buf)
1668{
1669    struct tipc_msg *msg = buf_msg(buf);
1670
1671    warn("Retransmission failure on link <%s>\n", l_ptr->name);
1672    tipc_msg_dbg(TIPC_OUTPUT, msg, ">RETR-FAIL>");
1673
1674    if (l_ptr->addr) {
1675
1676        /* Handle failure on standard link */
1677
1678        link_print(l_ptr, TIPC_OUTPUT, "Resetting link\n");
1679        tipc_link_reset(l_ptr);
1680
1681    } else {
1682
1683        /* Handle failure on broadcast link */
1684
1685        struct tipc_node *n_ptr;
1686        char addr_string[16];
1687
1688        tipc_printf(TIPC_OUTPUT, "Msg seq number: %u, ", msg_seqno(msg));
1689        tipc_printf(TIPC_OUTPUT, "Outstanding acks: %lu\n",
1690                     (unsigned long) TIPC_SKB_CB(buf)->handle);
1691
1692        n_ptr = l_ptr->owner->next;
1693        tipc_node_lock(n_ptr);
1694
1695        addr_string_fill(addr_string, n_ptr->addr);
1696        tipc_printf(TIPC_OUTPUT, "Multicast link info for %s\n", addr_string);
1697        tipc_printf(TIPC_OUTPUT, "Supported: %d, ", n_ptr->bclink.supported);
1698        tipc_printf(TIPC_OUTPUT, "Acked: %u\n", n_ptr->bclink.acked);
1699        tipc_printf(TIPC_OUTPUT, "Last in: %u, ", n_ptr->bclink.last_in);
1700        tipc_printf(TIPC_OUTPUT, "Gap after: %u, ", n_ptr->bclink.gap_after);
1701        tipc_printf(TIPC_OUTPUT, "Gap to: %u\n", n_ptr->bclink.gap_to);
1702        tipc_printf(TIPC_OUTPUT, "Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
1703
1704        tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1705
1706        tipc_node_unlock(n_ptr);
1707
1708        l_ptr->stale_count = 0;
1709    }
1710}
1711
1712void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
1713              u32 retransmits)
1714{
1715    struct tipc_msg *msg;
1716
1717    if (!buf)
1718        return;
1719
1720    msg = buf_msg(buf);
1721
1722    dbg("Retransmitting %u in link %x\n", retransmits, l_ptr);
1723
1724    if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1725        if (!skb_cloned(buf)) {
1726            msg_dbg(msg, ">NO_RETR->BCONG>");
1727            dbg_print_link(l_ptr, " ");
1728            l_ptr->retransm_queue_head = msg_seqno(msg);
1729            l_ptr->retransm_queue_size = retransmits;
1730            return;
1731        } else {
1732            /* Don't retransmit if driver already has the buffer */
1733        }
1734    } else {
1735        /* Detect repeated retransmit failures on uncongested bearer */
1736
1737        if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1738            if (++l_ptr->stale_count > 100) {
1739                link_retransmit_failure(l_ptr, buf);
1740                return;
1741            }
1742        } else {
1743            l_ptr->last_retransmitted = msg_seqno(msg);
1744            l_ptr->stale_count = 1;
1745        }
1746    }
1747
1748    while (retransmits && (buf != l_ptr->next_out) && buf && !skb_cloned(buf)) {
1749        msg = buf_msg(buf);
1750        msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1751        msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1752        if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1753            msg_dbg(buf_msg(buf), ">RETR>");
1754            buf = buf->next;
1755            retransmits--;
1756            l_ptr->stats.retransmitted++;
1757        } else {
1758            tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1759            l_ptr->stats.bearer_congs++;
1760            l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
1761            l_ptr->retransm_queue_size = retransmits;
1762            return;
1763        }
1764    }
1765
1766    l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1767}
1768
1769/**
1770 * link_insert_deferred_queue - insert deferred messages back into receive chain
1771 */
1772
1773static struct sk_buff *link_insert_deferred_queue(struct link *l_ptr,
1774                          struct sk_buff *buf)
1775{
1776    u32 seq_no;
1777
1778    if (l_ptr->oldest_deferred_in == NULL)
1779        return buf;
1780
1781    seq_no = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
1782    if (seq_no == mod(l_ptr->next_in_no)) {
1783        l_ptr->newest_deferred_in->next = buf;
1784        buf = l_ptr->oldest_deferred_in;
1785        l_ptr->oldest_deferred_in = NULL;
1786        l_ptr->deferred_inqueue_sz = 0;
1787    }
1788    return buf;
1789}
1790
1791/**
1792 * link_recv_buf_validate - validate basic format of received message
1793 *
1794 * This routine ensures a TIPC message has an acceptable header, and at least
1795 * as much data as the header indicates it should. The routine also ensures
1796 * that the entire message header is stored in the main fragment of the message
1797 * buffer, to simplify future access to message header fields.
1798 *
1799 * Note: Having extra info present in the message header or data areas is OK.
1800 * TIPC will ignore the excess, under the assumption that it is optional info
1801 * introduced by a later release of the protocol.
1802 */
1803
1804static int link_recv_buf_validate(struct sk_buff *buf)
1805{
1806    static u32 min_data_hdr_size[8] = {
1807        SHORT_H_SIZE, MCAST_H_SIZE, LONG_H_SIZE, DIR_MSG_H_SIZE,
1808        MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1809        };
1810
1811    struct tipc_msg *msg;
1812    u32 tipc_hdr[2];
1813    u32 size;
1814    u32 hdr_size;
1815    u32 min_hdr_size;
1816
1817    if (unlikely(buf->len < MIN_H_SIZE))
1818        return 0;
1819
1820    msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1821    if (msg == NULL)
1822        return 0;
1823
1824    if (unlikely(msg_version(msg) != TIPC_VERSION))
1825        return 0;
1826
1827    size = msg_size(msg);
1828    hdr_size = msg_hdr_sz(msg);
1829    min_hdr_size = msg_isdata(msg) ?
1830        min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1831
1832    if (unlikely((hdr_size < min_hdr_size) ||
1833             (size < hdr_size) ||
1834             (buf->len < size) ||
1835             (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1836        return 0;
1837
1838    return pskb_may_pull(buf, hdr_size);
1839}
1840
1841void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr)
1842{
1843    read_lock_bh(&tipc_net_lock);
1844    while (head) {
1845        struct bearer *b_ptr = (struct bearer *)tb_ptr;
1846        struct tipc_node *n_ptr;
1847        struct link *l_ptr;
1848        struct sk_buff *crs;
1849        struct sk_buff *buf = head;
1850        struct tipc_msg *msg;
1851        u32 seq_no;
1852        u32 ackd;
1853        u32 released = 0;
1854        int type;
1855
1856        head = head->next;
1857
1858        /* Ensure message is well-formed */
1859
1860        if (unlikely(!link_recv_buf_validate(buf)))
1861            goto cont;
1862
1863        /* Ensure message data is a single contiguous unit */
1864
1865        if (unlikely(buf_linearize(buf))) {
1866            goto cont;
1867        }
1868
1869        /* Handle arrival of a non-unicast link message */
1870
1871        msg = buf_msg(buf);
1872
1873        if (unlikely(msg_non_seq(msg))) {
1874            if (msg_user(msg) == LINK_CONFIG)
1875                tipc_disc_recv_msg(buf, b_ptr);
1876            else
1877                tipc_bclink_recv_pkt(buf);
1878            continue;
1879        }
1880
1881        if (unlikely(!msg_short(msg) &&
1882                 (msg_destnode(msg) != tipc_own_addr)))
1883            goto cont;
1884
1885        /* Locate unicast link endpoint that should handle message */
1886
1887        n_ptr = tipc_node_find(msg_prevnode(msg));
1888        if (unlikely(!n_ptr))
1889            goto cont;
1890        tipc_node_lock(n_ptr);
1891
1892        l_ptr = n_ptr->links[b_ptr->identity];
1893        if (unlikely(!l_ptr)) {
1894            tipc_node_unlock(n_ptr);
1895            goto cont;
1896        }
1897
1898        /* Validate message sequence number info */
1899
1900        seq_no = msg_seqno(msg);
1901        ackd = msg_ack(msg);
1902
1903        /* Release acked messages */
1904
1905        if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) {
1906            if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
1907                tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1908        }
1909
1910        crs = l_ptr->first_out;
1911        while ((crs != l_ptr->next_out) &&
1912               less_eq(msg_seqno(buf_msg(crs)), ackd)) {
1913            struct sk_buff *next = crs->next;
1914
1915            buf_discard(crs);
1916            crs = next;
1917            released++;
1918        }
1919        if (released) {
1920            l_ptr->first_out = crs;
1921            l_ptr->out_queue_size -= released;
1922        }
1923
1924        /* Try sending any messages link endpoint has pending */
1925
1926        if (unlikely(l_ptr->next_out))
1927            tipc_link_push_queue(l_ptr);
1928        if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1929            tipc_link_wakeup_ports(l_ptr, 0);
1930        if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1931            l_ptr->stats.sent_acks++;
1932            tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1933        }
1934
1935        /* Now (finally!) process the incoming message */
1936
1937protocol_check:
1938        if (likely(link_working_working(l_ptr))) {
1939            if (likely(seq_no == mod(l_ptr->next_in_no))) {
1940                l_ptr->next_in_no++;
1941                if (unlikely(l_ptr->oldest_deferred_in))
1942                    head = link_insert_deferred_queue(l_ptr,
1943                                      head);
1944                if (likely(msg_is_dest(msg, tipc_own_addr))) {
1945deliver:
1946                    if (likely(msg_isdata(msg))) {
1947                        tipc_node_unlock(n_ptr);
1948                        tipc_port_recv_msg(buf);
1949                        continue;
1950                    }
1951                    switch (msg_user(msg)) {
1952                    case MSG_BUNDLER:
1953                        l_ptr->stats.recv_bundles++;
1954                        l_ptr->stats.recv_bundled +=
1955                            msg_msgcnt(msg);
1956                        tipc_node_unlock(n_ptr);
1957                        tipc_link_recv_bundle(buf);
1958                        continue;
1959                    case ROUTE_DISTRIBUTOR:
1960                        tipc_node_unlock(n_ptr);
1961                        tipc_cltr_recv_routing_table(buf);
1962                        continue;
1963                    case NAME_DISTRIBUTOR:
1964                        tipc_node_unlock(n_ptr);
1965                        tipc_named_recv(buf);
1966                        continue;
1967                    case CONN_MANAGER:
1968                        tipc_node_unlock(n_ptr);
1969                        tipc_port_recv_proto_msg(buf);
1970                        continue;
1971                    case MSG_FRAGMENTER:
1972                        l_ptr->stats.recv_fragments++;
1973                        if (tipc_link_recv_fragment(&l_ptr->defragm_buf,
1974                                        &buf, &msg)) {
1975                            l_ptr->stats.recv_fragmented++;
1976                            goto deliver;
1977                        }
1978                        break;
1979                    case CHANGEOVER_PROTOCOL:
1980                        type = msg_type(msg);
1981                        if (link_recv_changeover_msg(&l_ptr, &buf)) {
1982                            msg = buf_msg(buf);
1983                            seq_no = msg_seqno(msg);
1984                            if (type == ORIGINAL_MSG)
1985                                goto deliver;
1986                            goto protocol_check;
1987                        }
1988                        break;
1989                    }
1990                }
1991                tipc_node_unlock(n_ptr);
1992                tipc_net_route_msg(buf);
1993                continue;
1994            }
1995            link_handle_out_of_seq_msg(l_ptr, buf);
1996            head = link_insert_deferred_queue(l_ptr, head);
1997            tipc_node_unlock(n_ptr);
1998            continue;
1999        }
2000
2001        if (msg_user(msg) == LINK_PROTOCOL) {
2002            link_recv_proto_msg(l_ptr, buf);
2003            head = link_insert_deferred_queue(l_ptr, head);
2004            tipc_node_unlock(n_ptr);
2005            continue;
2006        }
2007        msg_dbg(msg,"NSEQ<REC<");
2008        link_state_event(l_ptr, TRAFFIC_MSG_EVT);
2009
2010        if (link_working_working(l_ptr)) {
2011            /* Re-insert in front of queue */
2012            msg_dbg(msg,"RECV-REINS:");
2013            buf->next = head;
2014            head = buf;
2015            tipc_node_unlock(n_ptr);
2016            continue;
2017        }
2018        tipc_node_unlock(n_ptr);
2019cont:
2020        buf_discard(buf);
2021    }
2022    read_unlock_bh(&tipc_net_lock);
2023}
2024
2025/*
2026 * link_defer_buf(): Sort a received out-of-sequence packet
2027 * into the deferred reception queue.
2028 * Returns the increase of the queue length,i.e. 0 or 1
2029 */
2030
2031u32 tipc_link_defer_pkt(struct sk_buff **head,
2032            struct sk_buff **tail,
2033            struct sk_buff *buf)
2034{
2035    struct sk_buff *prev = NULL;
2036    struct sk_buff *crs = *head;
2037    u32 seq_no = msg_seqno(buf_msg(buf));
2038
2039    buf->next = NULL;
2040
2041    /* Empty queue ? */
2042    if (*head == NULL) {
2043        *head = *tail = buf;
2044        return 1;
2045    }
2046
2047    /* Last ? */
2048    if (less(msg_seqno(buf_msg(*tail)), seq_no)) {
2049        (*tail)->next = buf;
2050        *tail = buf;
2051        return 1;
2052    }
2053
2054    /* Scan through queue and sort it in */
2055    do {
2056        struct tipc_msg *msg = buf_msg(crs);
2057
2058        if (less(seq_no, msg_seqno(msg))) {
2059            buf->next = crs;
2060            if (prev)
2061                prev->next = buf;
2062            else
2063                *head = buf;
2064            return 1;
2065        }
2066        if (seq_no == msg_seqno(msg)) {
2067            break;
2068        }
2069        prev = crs;
2070        crs = crs->next;
2071    }
2072    while (crs);
2073
2074    /* Message is a duplicate of an existing message */
2075
2076    buf_discard(buf);
2077    return 0;
2078}
2079
2080/**
2081 * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
2082 */
2083
2084static void link_handle_out_of_seq_msg(struct link *l_ptr,
2085                       struct sk_buff *buf)
2086{
2087    u32 seq_no = msg_seqno(buf_msg(buf));
2088
2089    if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
2090        link_recv_proto_msg(l_ptr, buf);
2091        return;
2092    }
2093
2094    dbg("rx OOS msg: seq_no %u, expecting %u (%u)\n",
2095        seq_no, mod(l_ptr->next_in_no), l_ptr->next_in_no);
2096
2097    /* Record OOS packet arrival (force mismatch on next timeout) */
2098
2099    l_ptr->checkpoint--;
2100
2101    /*
2102     * Discard packet if a duplicate; otherwise add it to deferred queue
2103     * and notify peer of gap as per protocol specification
2104     */
2105
2106    if (less(seq_no, mod(l_ptr->next_in_no))) {
2107        l_ptr->stats.duplicates++;
2108        buf_discard(buf);
2109        return;
2110    }
2111
2112    if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
2113                &l_ptr->newest_deferred_in, buf)) {
2114        l_ptr->deferred_inqueue_sz++;
2115        l_ptr->stats.deferred_recv++;
2116        if ((l_ptr->deferred_inqueue_sz % 16) == 1)
2117            tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
2118    } else
2119        l_ptr->stats.duplicates++;
2120}
2121
2122/*
2123 * Send protocol message to the other endpoint.
2124 */
2125void tipc_link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int probe_msg,
2126                  u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
2127{
2128    struct sk_buff *buf = NULL;
2129    struct tipc_msg *msg = l_ptr->pmsg;
2130    u32 msg_size = sizeof(l_ptr->proto_msg);
2131
2132    if (link_blocked(l_ptr))
2133        return;
2134    msg_set_type(msg, msg_typ);
2135    msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
2136    msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in));
2137    msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
2138
2139    if (msg_typ == STATE_MSG) {
2140        u32 next_sent = mod(l_ptr->next_out_no);
2141
2142        if (!tipc_link_is_up(l_ptr))
2143            return;
2144        if (l_ptr->next_out)
2145            next_sent = msg_seqno(buf_msg(l_ptr->next_out));
2146        msg_set_next_sent(msg, next_sent);
2147        if (l_ptr->oldest_deferred_in) {
2148            u32 rec = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
2149            gap = mod(rec - mod(l_ptr->next_in_no));
2150        }
2151        msg_set_seq_gap(msg, gap);
2152        if (gap)
2153            l_ptr->stats.sent_nacks++;
2154        msg_set_link_tolerance(msg, tolerance);
2155        msg_set_linkprio(msg, priority);
2156        msg_set_max_pkt(msg, ack_mtu);
2157        msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
2158        msg_set_probe(msg, probe_msg != 0);
2159        if (probe_msg) {
2160            u32 mtu = l_ptr->max_pkt;
2161
2162            if ((mtu < l_ptr->max_pkt_target) &&
2163                link_working_working(l_ptr) &&
2164                l_ptr->fsm_msg_cnt) {
2165                msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
2166                if (l_ptr->max_pkt_probes == 10) {
2167                    l_ptr->max_pkt_target = (msg_size - 4);
2168                    l_ptr->max_pkt_probes = 0;
2169                    msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
2170                }
2171                l_ptr->max_pkt_probes++;
2172            }
2173
2174            l_ptr->stats.sent_probes++;
2175        }
2176        l_ptr->stats.sent_states++;
2177    } else { /* RESET_MSG or ACTIVATE_MSG */
2178        msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
2179        msg_set_seq_gap(msg, 0);
2180        msg_set_next_sent(msg, 1);
2181        msg_set_link_tolerance(msg, l_ptr->tolerance);
2182        msg_set_linkprio(msg, l_ptr->priority);
2183        msg_set_max_pkt(msg, l_ptr->max_pkt_target);
2184    }
2185
2186    if (tipc_node_has_redundant_links(l_ptr->owner)) {
2187        msg_set_redundant_link(msg);
2188    } else {
2189        msg_clear_redundant_link(msg);
2190    }
2191    msg_set_linkprio(msg, l_ptr->priority);
2192
2193    /* Ensure sequence number will not fit : */
2194
2195    msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
2196
2197    /* Congestion? */
2198
2199    if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
2200        if (!l_ptr->proto_msg_queue) {
2201            l_ptr->proto_msg_queue =
2202                buf_acquire(sizeof(l_ptr->proto_msg));
2203        }
2204        buf = l_ptr->proto_msg_queue;
2205        if (!buf)
2206            return;
2207        skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
2208        return;
2209    }
2210    msg_set_timestamp(msg, jiffies_to_msecs(jiffies));
2211
2212    /* Message can be sent */
2213
2214    msg_dbg(msg, ">>");
2215
2216    buf = buf_acquire(msg_size);
2217    if (!buf)
2218        return;
2219
2220    skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
2221    msg_set_size(buf_msg(buf), msg_size);
2222
2223    if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
2224        l_ptr->unacked_window = 0;
2225        buf_discard(buf);
2226        return;
2227    }
2228
2229    /* New congestion */
2230    tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
2231    l_ptr->proto_msg_queue = buf;
2232    l_ptr->stats.bearer_congs++;
2233}
2234
2235/*
2236 * Receive protocol message :
2237 * Note that network plane id propagates through the network, and may
2238 * change at any time. The node with lowest address rules
2239 */
2240
2241static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf)
2242{
2243    u32 rec_gap = 0;
2244    u32 max_pkt_info;
2245    u32 max_pkt_ack;
2246    u32 msg_tol;
2247    struct tipc_msg *msg = buf_msg(buf);
2248
2249    dbg("AT(%u):", jiffies_to_msecs(jiffies));
2250    msg_dbg(msg, "<<");
2251    if (link_blocked(l_ptr))
2252        goto exit;
2253
2254    /* record unnumbered packet arrival (force mismatch on next timeout) */
2255
2256    l_ptr->checkpoint--;
2257
2258    if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
2259        if (tipc_own_addr > msg_prevnode(msg))
2260            l_ptr->b_ptr->net_plane = msg_net_plane(msg);
2261
2262    l_ptr->owner->permit_changeover = msg_redundant_link(msg);
2263
2264    switch (msg_type(msg)) {
2265
2266    case RESET_MSG:
2267        if (!link_working_unknown(l_ptr) &&
2268            (l_ptr->peer_session != INVALID_SESSION)) {
2269            if (msg_session(msg) == l_ptr->peer_session) {
2270                dbg("Duplicate RESET: %u<->%u\n",
2271                    msg_session(msg), l_ptr->peer_session);
2272                break; /* duplicate: ignore */
2273            }
2274        }
2275        /* fall thru' */
2276    case ACTIVATE_MSG:
2277        /* Update link settings according other endpoint's values */
2278
2279        strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
2280
2281        if ((msg_tol = msg_link_tolerance(msg)) &&
2282            (msg_tol > l_ptr->tolerance))
2283            link_set_supervision_props(l_ptr, msg_tol);
2284
2285        if (msg_linkprio(msg) > l_ptr->priority)
2286            l_ptr->priority = msg_linkprio(msg);
2287
2288        max_pkt_info = msg_max_pkt(msg);
2289        if (max_pkt_info) {
2290            if (max_pkt_info < l_ptr->max_pkt_target)
2291                l_ptr->max_pkt_target = max_pkt_info;
2292            if (l_ptr->max_pkt > l_ptr->max_pkt_target)
2293                l_ptr->max_pkt = l_ptr->max_pkt_target;
2294        } else {
2295            l_ptr->max_pkt = l_ptr->max_pkt_target;
2296        }
2297        l_ptr->owner->bclink.supported = (max_pkt_info != 0);
2298
2299        link_state_event(l_ptr, msg_type(msg));
2300
2301        l_ptr->peer_session = msg_session(msg);
2302        l_ptr->peer_bearer_id = msg_bearer_id(msg);
2303
2304        /* Synchronize broadcast sequence numbers */
2305        if (!tipc_node_has_redundant_links(l_ptr->owner)) {
2306            l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg));
2307        }
2308        break;
2309    case STATE_MSG:
2310
2311        if ((msg_tol = msg_link_tolerance(msg)))
2312            link_set_supervision_props(l_ptr, msg_tol);
2313
2314        if (msg_linkprio(msg) &&
2315            (msg_linkprio(msg) != l_ptr->priority)) {
2316            warn("Resetting link <%s>, priority change %u->%u\n",
2317                 l_ptr->name, l_ptr->priority, msg_linkprio(msg));
2318            l_ptr->priority = msg_linkprio(msg);
2319            tipc_link_reset(l_ptr); /* Enforce change to take effect */
2320            break;
2321        }
2322        link_state_event(l_ptr, TRAFFIC_MSG_EVT);
2323        l_ptr->stats.recv_states++;
2324        if (link_reset_unknown(l_ptr))
2325            break;
2326
2327        if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
2328            rec_gap = mod(msg_next_sent(msg) -
2329                      mod(l_ptr->next_in_no));
2330        }
2331
2332        max_pkt_ack = msg_max_pkt(msg);
2333        if (max_pkt_ack > l_ptr->max_pkt) {
2334            dbg("Link <%s> updated MTU %u -> %u\n",
2335                l_ptr->name, l_ptr->max_pkt, max_pkt_ack);
2336            l_ptr->max_pkt = max_pkt_ack;
2337            l_ptr->max_pkt_probes = 0;
2338        }
2339
2340        max_pkt_ack = 0;
2341        if (msg_probe(msg)) {
2342            l_ptr->stats.recv_probes++;
2343            if (msg_size(msg) > sizeof(l_ptr->proto_msg)) {
2344                max_pkt_ack = msg_size(msg);
2345            }
2346        }
2347
2348        /* Protocol message before retransmits, reduce loss risk */
2349
2350        tipc_bclink_check_gap(l_ptr->owner, msg_last_bcast(msg));
2351
2352        if (rec_gap || (msg_probe(msg))) {
2353            tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2354                         0, rec_gap, 0, 0, max_pkt_ack);
2355        }
2356        if (msg_seq_gap(msg)) {
2357            msg_dbg(msg, "With Gap:");
2358            l_ptr->stats.recv_nacks++;
2359            tipc_link_retransmit(l_ptr, l_ptr->first_out,
2360                         msg_seq_gap(msg));
2361        }
2362        break;
2363    default:
2364        msg_dbg(buf_msg(buf), "<DISCARDING UNKNOWN<");
2365    }
2366exit:
2367    buf_discard(buf);
2368}
2369
2370
2371/*
2372 * tipc_link_tunnel(): Send one message via a link belonging to
2373 * another bearer. Owner node is locked.
2374 */
2375void tipc_link_tunnel(struct link *l_ptr,
2376              struct tipc_msg *tunnel_hdr,
2377              struct tipc_msg *msg,
2378              u32 selector)
2379{
2380    struct link *tunnel;
2381    struct sk_buff *buf;
2382    u32 length = msg_size(msg);
2383
2384    tunnel = l_ptr->owner->active_links[selector & 1];
2385    if (!tipc_link_is_up(tunnel)) {
2386        warn("Link changeover error, "
2387             "tunnel link no longer available\n");
2388        return;
2389    }
2390    msg_set_size(tunnel_hdr, length + INT_H_SIZE);
2391    buf = buf_acquire(length + INT_H_SIZE);
2392    if (!buf) {
2393        warn("Link changeover error, "
2394             "unable to send tunnel msg\n");
2395        return;
2396    }
2397    skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
2398    skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
2399    dbg("%c->%c:", l_ptr->b_ptr->net_plane, tunnel->b_ptr->net_plane);
2400    msg_dbg(buf_msg(buf), ">SEND>");
2401    tipc_link_send_buf(tunnel, buf);
2402}
2403
2404
2405
2406/*
2407 * changeover(): Send whole message queue via the remaining link
2408 * Owner node is locked.
2409 */
2410
2411void tipc_link_changeover(struct link *l_ptr)
2412{
2413    u32 msgcount = l_ptr->out_queue_size;
2414    struct sk_buff *crs = l_ptr->first_out;
2415    struct link *tunnel = l_ptr->owner->active_links[0];
2416    struct tipc_msg tunnel_hdr;
2417    int split_bundles;
2418
2419    if (!tunnel)
2420        return;
2421
2422    if (!l_ptr->owner->permit_changeover) {
2423        warn("Link changeover error, "
2424             "peer did not permit changeover\n");
2425        return;
2426    }
2427
2428    msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2429         ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2430    msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2431    msg_set_msgcnt(&tunnel_hdr, msgcount);
2432    dbg("Link changeover requires %u tunnel messages\n", msgcount);
2433
2434    if (!l_ptr->first_out) {
2435        struct sk_buff *buf;
2436
2437        buf = buf_acquire(INT_H_SIZE);
2438        if (buf) {
2439            skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2440            msg_set_size(&tunnel_hdr, INT_H_SIZE);
2441            dbg("%c->%c:", l_ptr->b_ptr->net_plane,
2442                tunnel->b_ptr->net_plane);
2443            msg_dbg(&tunnel_hdr, "EMPTY>SEND>");
2444            tipc_link_send_buf(tunnel, buf);
2445        } else {
2446            warn("Link changeover error, "
2447                 "unable to send changeover msg\n");
2448        }
2449        return;
2450    }
2451
2452    split_bundles = (l_ptr->owner->active_links[0] !=
2453             l_ptr->owner->active_links[1]);
2454
2455    while (crs) {
2456        struct tipc_msg *msg = buf_msg(crs);
2457
2458        if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2459            struct tipc_msg *m = msg_get_wrapped(msg);
2460            unchar* pos = (unchar*)m;
2461
2462            msgcount = msg_msgcnt(msg);
2463            while (msgcount--) {
2464                msg_set_seqno(m,msg_seqno(msg));
2465                tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
2466                         msg_link_selector(m));
2467                pos += align(msg_size(m));
2468                m = (struct tipc_msg *)pos;
2469            }
2470        } else {
2471            tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
2472                     msg_link_selector(msg));
2473        }
2474        crs = crs->next;
2475    }
2476}
2477
2478void tipc_link_send_duplicate(struct link *l_ptr, struct link *tunnel)
2479{
2480    struct sk_buff *iter;
2481    struct tipc_msg tunnel_hdr;
2482
2483    msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2484         DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2485    msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2486    msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2487    iter = l_ptr->first_out;
2488    while (iter) {
2489        struct sk_buff *outbuf;
2490        struct tipc_msg *msg = buf_msg(iter);
2491        u32 length = msg_size(msg);
2492
2493        if (msg_user(msg) == MSG_BUNDLER)
2494            msg_set_type(msg, CLOSED_MSG);
2495        msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); /* Update */
2496        msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2497        msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2498        outbuf = buf_acquire(length + INT_H_SIZE);
2499        if (outbuf == NULL) {
2500            warn("Link changeover error, "
2501                 "unable to send duplicate msg\n");
2502            return;
2503        }
2504        skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2505        skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2506                           length);
2507        dbg("%c->%c:", l_ptr->b_ptr->net_plane,
2508            tunnel->b_ptr->net_plane);
2509        msg_dbg(buf_msg(outbuf), ">SEND>");
2510        tipc_link_send_buf(tunnel, outbuf);
2511        if (!tipc_link_is_up(l_ptr))
2512            return;
2513        iter = iter->next;
2514    }
2515}
2516
2517
2518
2519/**
2520 * buf_extract - extracts embedded TIPC message from another message
2521 * @skb: encapsulating message buffer
2522 * @from_pos: offset to extract from
2523 *
2524 * Returns a new message buffer containing an embedded message. The
2525 * encapsulating message itself is left unchanged.
2526 */
2527
2528static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2529{
2530    struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2531    u32 size = msg_size(msg);
2532    struct sk_buff *eb;
2533
2534    eb = buf_acquire(size);
2535    if (eb)
2536        skb_copy_to_linear_data(eb, msg, size);
2537    return eb;
2538}
2539
2540/*
2541 * link_recv_changeover_msg(): Receive tunneled packet sent
2542 * via other link. Node is locked. Return extracted buffer.
2543 */
2544
2545static int link_recv_changeover_msg(struct link **l_ptr,
2546                    struct sk_buff **buf)
2547{
2548    struct sk_buff *tunnel_buf = *buf;
2549    struct link *dest_link;
2550    struct tipc_msg *msg;
2551    struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
2552    u32 msg_typ = msg_type(tunnel_msg);
2553    u32 msg_count = msg_msgcnt(tunnel_msg);
2554
2555    dest_link = (*l_ptr)->owner->links[msg_bearer_id(tunnel_msg)];
2556    if (!dest_link) {
2557        msg_dbg(tunnel_msg, "NOLINK/<REC<");
2558        goto exit;
2559    }
2560    if (dest_link == *l_ptr) {
2561        err("Unexpected changeover message on link <%s>\n",
2562            (*l_ptr)->name);
2563        goto exit;
2564    }
2565    dbg("%c<-%c:", dest_link->b_ptr->net_plane,
2566        (*l_ptr)->b_ptr->net_plane);
2567    *l_ptr = dest_link;
2568    msg = msg_get_wrapped(tunnel_msg);
2569
2570    if (msg_typ == DUPLICATE_MSG) {
2571        if (less(msg_seqno(msg), mod(dest_link->next_in_no))) {
2572            msg_dbg(tunnel_msg, "DROP/<REC<");
2573            goto exit;
2574        }
2575        *buf = buf_extract(tunnel_buf,INT_H_SIZE);
2576        if (*buf == NULL) {
2577            warn("Link changeover error, duplicate msg dropped\n");
2578            goto exit;
2579        }
2580        msg_dbg(tunnel_msg, "TNL<REC<");
2581        buf_discard(tunnel_buf);
2582        return 1;
2583    }
2584
2585    /* First original message ?: */
2586
2587    if (tipc_link_is_up(dest_link)) {
2588        msg_dbg(tunnel_msg, "UP/FIRST/<REC<");
2589        info("Resetting link <%s>, changeover initiated by peer\n",
2590             dest_link->name);
2591        tipc_link_reset(dest_link);
2592        dest_link->exp_msg_count = msg_count;
2593        dbg("Expecting %u tunnelled messages\n", msg_count);
2594        if (!msg_count)
2595            goto exit;
2596    } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
2597        msg_dbg(tunnel_msg, "BLK/FIRST/<REC<");
2598        dest_link->exp_msg_count = msg_count;
2599        dbg("Expecting %u tunnelled messages\n", msg_count);
2600        if (!msg_count)
2601            goto exit;
2602    }
2603
2604    /* Receive original message */
2605
2606    if (dest_link->exp_msg_count == 0) {
2607        warn("Link switchover error, "
2608             "got too many tunnelled messages\n");
2609        msg_dbg(tunnel_msg, "OVERDUE/DROP/<REC<");
2610        dbg_print_link(dest_link, "LINK:");
2611        goto exit;
2612    }
2613    dest_link->exp_msg_count--;
2614    if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
2615        msg_dbg(tunnel_msg, "DROP/DUPL/<REC<");
2616        goto exit;
2617    } else {
2618        *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2619        if (*buf != NULL) {
2620            msg_dbg(tunnel_msg, "TNL<REC<");
2621            buf_discard(tunnel_buf);
2622            return 1;
2623        } else {
2624            warn("Link changeover error, original msg dropped\n");
2625        }
2626    }
2627exit:
2628    *buf = NULL;
2629    buf_discard(tunnel_buf);
2630    return 0;
2631}
2632
2633/*
2634 * Bundler functionality:
2635 */
2636void tipc_link_recv_bundle(struct sk_buff *buf)
2637{
2638    u32 msgcount = msg_msgcnt(buf_msg(buf));
2639    u32 pos = INT_H_SIZE;
2640    struct sk_buff *obuf;
2641
2642    msg_dbg(buf_msg(buf), "<BNDL<: ");
2643    while (msgcount--) {
2644        obuf = buf_extract(buf, pos);
2645        if (obuf == NULL) {
2646            warn("Link unable to unbundle message(s)\n");
2647            break;
2648        }
2649        pos += align(msg_size(buf_msg(obuf)));
2650        msg_dbg(buf_msg(obuf), " /");
2651        tipc_net_route_msg(obuf);
2652    }
2653    buf_discard(buf);
2654}
2655
2656/*
2657 * Fragmentation/defragmentation:
2658 */
2659
2660
2661/*
2662 * tipc_link_send_long_buf: Entry for buffers needing fragmentation.
2663 * The buffer is complete, inclusive total message length.
2664 * Returns user data length.
2665 */
2666int tipc_link_send_long_buf(struct link *l_ptr, struct sk_buff *buf)
2667{
2668    struct tipc_msg *inmsg = buf_msg(buf);
2669    struct tipc_msg fragm_hdr;
2670    u32 insize = msg_size(inmsg);
2671    u32 dsz = msg_data_sz(inmsg);
2672    unchar *crs = buf->data;
2673    u32 rest = insize;
2674    u32 pack_sz = link_max_pkt(l_ptr);
2675    u32 fragm_sz = pack_sz - INT_H_SIZE;
2676    u32 fragm_no = 1;
2677    u32 destaddr;
2678
2679    if (msg_short(inmsg))
2680        destaddr = l_ptr->addr;
2681    else
2682        destaddr = msg_destnode(inmsg);
2683
2684    if (msg_routed(inmsg))
2685        msg_set_prevnode(inmsg, tipc_own_addr);
2686
2687    /* Prepare reusable fragment header: */
2688
2689    msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2690         INT_H_SIZE, destaddr);
2691    msg_set_link_selector(&fragm_hdr, msg_link_selector(inmsg));
2692    msg_set_long_msgno(&fragm_hdr, mod(l_ptr->long_msg_seq_no++));
2693    msg_set_fragm_no(&fragm_hdr, fragm_no);
2694    l_ptr->stats.sent_fragmented++;
2695
2696    /* Chop up message: */
2697
2698    while (rest > 0) {
2699        struct sk_buff *fragm;
2700
2701        if (rest <= fragm_sz) {
2702            fragm_sz = rest;
2703            msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2704        }
2705        fragm = buf_acquire(fragm_sz + INT_H_SIZE);
2706        if (fragm == NULL) {
2707            warn("Link unable to fragment message\n");
2708            dsz = -ENOMEM;
2709            goto exit;
2710        }
2711        msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2712        skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2713        skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2714                           fragm_sz);
2715        /* Send queued messages first, if any: */
2716
2717        l_ptr->stats.sent_fragments++;
2718        tipc_link_send_buf(l_ptr, fragm);
2719        if (!tipc_link_is_up(l_ptr))
2720            return dsz;
2721        msg_set_fragm_no(&fragm_hdr, ++fragm_no);
2722        rest -= fragm_sz;
2723        crs += fragm_sz;
2724        msg_set_type(&fragm_hdr, FRAGMENT);
2725    }
2726exit:
2727    buf_discard(buf);
2728    return dsz;
2729}
2730
2731/*
2732 * A pending message being re-assembled must store certain values
2733 * to handle subsequent fragments correctly. The following functions
2734 * help storing these values in unused, available fields in the
2735 * pending message. This makes dynamic memory allocation unecessary.
2736 */
2737
2738static void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
2739{
2740    msg_set_seqno(buf_msg(buf), seqno);
2741}
2742
2743static u32 get_fragm_size(struct sk_buff *buf)
2744{
2745    return msg_ack(buf_msg(buf));
2746}
2747
2748static void set_fragm_size(struct sk_buff *buf, u32 sz)
2749{
2750    msg_set_ack(buf_msg(buf), sz);
2751}
2752
2753static u32 get_expected_frags(struct sk_buff *buf)
2754{
2755    return msg_bcast_ack(buf_msg(buf));
2756}
2757
2758static void set_expected_frags(struct sk_buff *buf, u32 exp)
2759{
2760    msg_set_bcast_ack(buf_msg(buf), exp);
2761}
2762
2763static u32 get_timer_cnt(struct sk_buff *buf)
2764{
2765    return msg_reroute_cnt(buf_msg(buf));
2766}
2767
2768static void incr_timer_cnt(struct sk_buff *buf)
2769{
2770    msg_incr_reroute_cnt(buf_msg(buf));
2771}
2772
2773/*
2774 * tipc_link_recv_fragment(): Called with node lock on. Returns
2775 * the reassembled buffer if message is complete.
2776 */
2777int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
2778                struct tipc_msg **m)
2779{
2780    struct sk_buff *prev = NULL;
2781    struct sk_buff *fbuf = *fb;
2782    struct tipc_msg *fragm = buf_msg(fbuf);
2783    struct sk_buff *pbuf = *pending;
2784    u32 long_msg_seq_no = msg_long_msgno(fragm);
2785
2786    *fb = NULL;
2787    msg_dbg(fragm,"FRG<REC<");
2788
2789    /* Is there an incomplete message waiting for this fragment? */
2790
2791    while (pbuf && ((msg_seqno(buf_msg(pbuf)) != long_msg_seq_no)
2792            || (msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
2793        prev = pbuf;
2794        pbuf = pbuf->next;
2795    }
2796
2797    if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
2798        struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
2799        u32 msg_sz = msg_size(imsg);
2800        u32 fragm_sz = msg_data_sz(fragm);
2801        u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
2802        u32 max = TIPC_MAX_USER_MSG_SIZE + LONG_H_SIZE;
2803        if (msg_type(imsg) == TIPC_MCAST_MSG)
2804            max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
2805        if (msg_size(imsg) > max) {
2806            msg_dbg(fragm,"<REC<Oversized: ");
2807            buf_discard(fbuf);
2808            return 0;
2809        }
2810        pbuf = buf_acquire(msg_size(imsg));
2811        if (pbuf != NULL) {
2812            pbuf->next = *pending;
2813            *pending = pbuf;
2814            skb_copy_to_linear_data(pbuf, imsg,
2815                        msg_data_sz(fragm));
2816            /* Prepare buffer for subsequent fragments. */
2817
2818            set_long_msg_seqno(pbuf, long_msg_seq_no);
2819            set_fragm_size(pbuf,fragm_sz);
2820            set_expected_frags(pbuf,exp_fragm_cnt - 1);
2821        } else {
2822            warn("Link unable to reassemble fragmented message\n");
2823        }
2824        buf_discard(fbuf);
2825        return 0;
2826    } else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
2827        u32 dsz = msg_data_sz(fragm);
2828        u32 fsz = get_fragm_size(pbuf);
2829        u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
2830        u32 exp_frags = get_expected_frags(pbuf) - 1;
2831        skb_copy_to_linear_data_offset(pbuf, crs,
2832                           msg_data(fragm), dsz);
2833        buf_discard(fbuf);
2834
2835        /* Is message complete? */
2836
2837        if (exp_frags == 0) {
2838            if (prev)
2839                prev->next = pbuf->next;
2840            else
2841                *pending = pbuf->next;
2842            msg_reset_reroute_cnt(buf_msg(pbuf));
2843            *fb = pbuf;
2844            *m = buf_msg(pbuf);
2845            return 1;
2846        }
2847        set_expected_frags(pbuf,exp_frags);
2848        return 0;
2849    }
2850    dbg(" Discarding orphan fragment %x\n",fbuf);
2851    msg_dbg(fragm,"ORPHAN:");
2852    dbg("Pending long buffers:\n");
2853    dbg_print_buf_chain(*pending);
2854    buf_discard(fbuf);
2855    return 0;
2856}
2857
2858/**
2859 * link_check_defragm_bufs - flush stale incoming message fragments
2860 * @l_ptr: pointer to link
2861 */
2862
2863static void link_check_defragm_bufs(struct link *l_ptr)
2864{
2865    struct sk_buff *prev = NULL;
2866    struct sk_buff *next = NULL;
2867    struct sk_buff *buf = l_ptr->defragm_buf;
2868
2869    if (!buf)
2870        return;
2871    if (!link_working_working(l_ptr))
2872        return;
2873    while (buf) {
2874        u32 cnt = get_timer_cnt(buf);
2875
2876        next = buf->next;
2877        if (cnt < 4) {
2878            incr_timer_cnt(buf);
2879            prev = buf;
2880        } else {
2881            dbg(" Discarding incomplete long buffer\n");
2882            msg_dbg(buf_msg(buf), "LONG:");
2883            dbg_print_link(l_ptr, "curr:");
2884            dbg("Pending long buffers:\n");
2885            dbg_print_buf_chain(l_ptr->defragm_buf);
2886            if (prev)
2887                prev->next = buf->next;
2888            else
2889                l_ptr->defragm_buf = buf->next;
2890            buf_discard(buf);
2891        }
2892        buf = next;
2893    }
2894}
2895
2896
2897
2898static void link_set_supervision_props(struct link *l_ptr, u32 tolerance)
2899{
2900    l_ptr->tolerance = tolerance;
2901    l_ptr->continuity_interval =
2902        ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2903    l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2904}
2905
2906
2907void tipc_link_set_queue_limits(struct link *l_ptr, u32 window)
2908{
2909    /* Data messages from this node, inclusive FIRST_FRAGM */
2910    l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2911    l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2912    l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2913    l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2914    /* Transiting data messages,inclusive FIRST_FRAGM */
2915    l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2916    l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2917    l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2918    l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2919    l_ptr->queue_limit[CONN_MANAGER] = 1200;
2920    l_ptr->queue_limit[ROUTE_DISTRIBUTOR] = 1200;
2921    l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2922    l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2923    /* FRAGMENT and LAST_FRAGMENT packets */
2924    l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2925}
2926
2927/**
2928 * link_find_link - locate link by name
2929 * @name - ptr to link name string
2930 * @node - ptr to area to be filled with ptr to associated node
2931 *
2932 * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2933 * this also prevents link deletion.
2934 *
2935 * Returns pointer to link (or 0 if invalid link name).
2936 */
2937
2938static struct link *link_find_link(const char *name, struct tipc_node **node)
2939{
2940    struct link_name link_name_parts;
2941    struct bearer *b_ptr;
2942    struct link *l_ptr;
2943
2944    if (!link_name_validate(name, &link_name_parts))
2945        return NULL;
2946
2947    b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
2948    if (!b_ptr)
2949        return NULL;
2950
2951    *node = tipc_node_find(link_name_parts.addr_peer);
2952    if (!*node)
2953        return NULL;
2954
2955    l_ptr = (*node)->links[b_ptr->identity];
2956    if (!l_ptr || strcmp(l_ptr->name, name))
2957        return NULL;
2958
2959    return l_ptr;
2960}
2961
2962struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2963                     u16 cmd)
2964{
2965    struct tipc_link_config *args;
2966    u32 new_value;
2967    struct link *l_ptr;
2968    struct tipc_node *node;
2969    int res;
2970
2971    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2972        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2973
2974    args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2975    new_value = ntohl(args->value);
2976
2977    if (!strcmp(args->name, tipc_bclink_name)) {
2978        if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2979            (tipc_bclink_set_queue_limits(new_value) == 0))
2980            return tipc_cfg_reply_none();
2981        return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2982                           " (cannot change setting on broadcast link)");
2983    }
2984
2985    read_lock_bh(&tipc_net_lock);
2986    l_ptr = link_find_link(args->name, &node);
2987    if (!l_ptr) {
2988        read_unlock_bh(&tipc_net_lock);
2989        return tipc_cfg_reply_error_string("link not found");
2990    }
2991
2992    tipc_node_lock(node);
2993    res = -EINVAL;
2994    switch (cmd) {
2995    case TIPC_CMD_SET_LINK_TOL:
2996        if ((new_value >= TIPC_MIN_LINK_TOL) &&
2997            (new_value <= TIPC_MAX_LINK_TOL)) {
2998            link_set_supervision_props(l_ptr, new_value);
2999            tipc_link_send_proto_msg(l_ptr, STATE_MSG,
3000                         0, 0, new_value, 0, 0);
3001            res = 0;
3002        }
3003        break;
3004    case TIPC_CMD_SET_LINK_PRI:
3005        if ((new_value >= TIPC_MIN_LINK_PRI) &&
3006            (new_value <= TIPC_MAX_LINK_PRI)) {
3007            l_ptr->priority = new_value;
3008            tipc_link_send_proto_msg(l_ptr, STATE_MSG,
3009                         0, 0, 0, new_value, 0);
3010            res = 0;
3011        }
3012        break;
3013    case TIPC_CMD_SET_LINK_WINDOW:
3014        if ((new_value >= TIPC_MIN_LINK_WIN) &&
3015            (new_value <= TIPC_MAX_LINK_WIN)) {
3016            tipc_link_set_queue_limits(l_ptr, new_value);
3017            res = 0;
3018        }
3019        break;
3020    }
3021    tipc_node_unlock(node);
3022
3023    read_unlock_bh(&tipc_net_lock);
3024    if (res)
3025        return tipc_cfg_reply_error_string("cannot change link setting");
3026
3027    return tipc_cfg_reply_none();
3028}
3029
3030/**
3031 * link_reset_statistics - reset link statistics
3032 * @l_ptr: pointer to link
3033 */
3034
3035static void link_reset_statistics(struct link *l_ptr)
3036{
3037    memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
3038    l_ptr->stats.sent_info = l_ptr->next_out_no;
3039    l_ptr->stats.recv_info = l_ptr->next_in_no;
3040}
3041
3042struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
3043{
3044    char *link_name;
3045    struct link *l_ptr;
3046    struct tipc_node *node;
3047
3048    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
3049        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
3050
3051    link_name = (char *)TLV_DATA(req_tlv_area);
3052    if (!strcmp(link_name, tipc_bclink_name)) {
3053        if (tipc_bclink_reset_stats())
3054            return tipc_cfg_reply_error_string("link not found");
3055        return tipc_cfg_reply_none();
3056    }
3057
3058    read_lock_bh(&tipc_net_lock);
3059    l_ptr = link_find_link(link_name, &node);
3060    if (!l_ptr) {
3061        read_unlock_bh(&tipc_net_lock);
3062        return tipc_cfg_reply_error_string("link not found");
3063    }
3064
3065    tipc_node_lock(node);
3066    link_reset_statistics(l_ptr);
3067    tipc_node_unlock(node);
3068    read_unlock_bh(&tipc_net_lock);
3069    return tipc_cfg_reply_none();
3070}
3071
3072/**
3073 * percent - convert count to a percentage of total (rounding up or down)
3074 */
3075
3076static u32 percent(u32 count, u32 total)
3077{
3078    return (count * 100 + (total / 2)) / total;
3079}
3080
3081/**
3082 * tipc_link_stats - print link statistics
3083 * @name: link name
3084 * @buf: print buffer area
3085 * @buf_size: size of print buffer area
3086 *
3087 * Returns length of print buffer data string (or 0 if error)
3088 */
3089
3090static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
3091{
3092    struct print_buf pb;
3093    struct link *l_ptr;
3094    struct tipc_node *node;
3095    char *status;
3096    u32 profile_total = 0;
3097
3098    if (!strcmp(name, tipc_bclink_name))
3099        return tipc_bclink_stats(buf, buf_size);
3100
3101    tipc_printbuf_init(&pb, buf, buf_size);
3102
3103    read_lock_bh(&tipc_net_lock);
3104    l_ptr = link_find_link(name, &node);
3105    if (!l_ptr) {
3106        read_unlock_bh(&tipc_net_lock);
3107        return 0;
3108    }
3109    tipc_node_lock(node);
3110
3111    if (tipc_link_is_active(l_ptr))
3112        status = "ACTIVE";
3113    else if (tipc_link_is_up(l_ptr))
3114        status = "STANDBY";
3115    else
3116        status = "DEFUNCT";
3117    tipc_printf(&pb, "Link <%s>\n"
3118             " %s MTU:%u Priority:%u Tolerance:%u ms"
3119             " Window:%u packets\n",
3120            l_ptr->name, status, link_max_pkt(l_ptr),
3121            l_ptr->priority, l_ptr->tolerance, l_ptr->queue_limit[0]);
3122    tipc_printf(&pb, " RX packets:%u fragments:%u/%u bundles:%u/%u\n",
3123            l_ptr->next_in_no - l_ptr->stats.recv_info,
3124            l_ptr->stats.recv_fragments,
3125            l_ptr->stats.recv_fragmented,
3126            l_ptr->stats.recv_bundles,
3127            l_ptr->stats.recv_bundled);
3128    tipc_printf(&pb, " TX packets:%u fragments:%u/%u bundles:%u/%u\n",
3129            l_ptr->next_out_no - l_ptr->stats.sent_info,
3130            l_ptr->stats.sent_fragments,
3131            l_ptr->stats.sent_fragmented,
3132            l_ptr->stats.sent_bundles,
3133            l_ptr->stats.sent_bundled);
3134    profile_total = l_ptr->stats.msg_length_counts;
3135    if (!profile_total)
3136        profile_total = 1;
3137    tipc_printf(&pb, " TX profile sample:%u packets average:%u octets\n"
3138             " 0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
3139             "-16354:%u%% -32768:%u%% -66000:%u%%\n",
3140            l_ptr->stats.msg_length_counts,
3141            l_ptr->stats.msg_lengths_total / profile_total,
3142            percent(l_ptr->stats.msg_length_profile[0], profile_total),
3143            percent(l_ptr->stats.msg_length_profile[1], profile_total),
3144            percent(l_ptr->stats.msg_length_profile[2], profile_total),
3145            percent(l_ptr->stats.msg_length_profile[3], profile_total),
3146            percent(l_ptr->stats.msg_length_profile[4], profile_total),
3147            percent(l_ptr->stats.msg_length_profile[5], profile_total),
3148            percent(l_ptr->stats.msg_length_profile[6], profile_total));
3149    tipc_printf(&pb, " RX states:%u probes:%u naks:%u defs:%u dups:%u\n",
3150            l_ptr->stats.recv_states,
3151            l_ptr->stats.recv_probes,
3152            l_ptr->stats.recv_nacks,
3153            l_ptr->stats.deferred_recv,
3154            l_ptr->stats.duplicates);
3155    tipc_printf(&pb, " TX states:%u probes:%u naks:%u acks:%u dups:%u\n",
3156            l_ptr->stats.sent_states,
3157            l_ptr->stats.sent_probes,
3158            l_ptr->stats.sent_nacks,
3159            l_ptr->stats.sent_acks,
3160            l_ptr->stats.retransmitted);
3161    tipc_printf(&pb, " Congestion bearer:%u link:%u Send queue max:%u avg:%u\n",
3162            l_ptr->stats.bearer_congs,
3163            l_ptr->stats.link_congs,
3164            l_ptr->stats.max_queue_sz,
3165            l_ptr->stats.queue_sz_counts
3166            ? (l_ptr->stats.accu_queue_sz / l_ptr->stats.queue_sz_counts)
3167            : 0);
3168
3169    tipc_node_unlock(node);
3170    read_unlock_bh(&tipc_net_lock);
3171    return tipc_printbuf_validate(&pb);
3172}
3173
3174#define MAX_LINK_STATS_INFO 2000
3175
3176struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
3177{
3178    struct sk_buff *buf;
3179    struct tlv_desc *rep_tlv;
3180    int str_len;
3181
3182    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
3183        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
3184
3185    buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_LINK_STATS_INFO));
3186    if (!buf)
3187        return NULL;
3188
3189    rep_tlv = (struct tlv_desc *)buf->data;
3190
3191    str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
3192                  (char *)TLV_DATA(rep_tlv), MAX_LINK_STATS_INFO);
3193    if (!str_len) {
3194        buf_discard(buf);
3195        return tipc_cfg_reply_error_string("link not found");
3196    }
3197
3198    skb_put(buf, TLV_SPACE(str_len));
3199    TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
3200
3201    return buf;
3202}
3203
3204#if 0
3205int link_control(const char *name, u32 op, u32 val)
3206{
3207    int res = -EINVAL;
3208    struct link *l_ptr;
3209    u32 bearer_id;
3210    struct tipc_node * node;
3211    u32 a;
3212
3213    a = link_name2addr(name, &bearer_id);
3214    read_lock_bh(&tipc_net_lock);
3215    node = tipc_node_find(a);
3216    if (node) {
3217        tipc_node_lock(node);
3218        l_ptr = node->links[bearer_id];
3219        if (l_ptr) {
3220            if (op == TIPC_REMOVE_LINK) {
3221                struct bearer *b_ptr = l_ptr->b_ptr;
3222                spin_lock_bh(&b_ptr->publ.lock);
3223                tipc_link_delete(l_ptr);
3224                spin_unlock_bh(&b_ptr->publ.lock);
3225            }
3226            if (op == TIPC_CMD_BLOCK_LINK) {
3227                tipc_link_reset(l_ptr);
3228                l_ptr->blocked = 1;
3229            }
3230            if (op == TIPC_CMD_UNBLOCK_LINK) {
3231                l_ptr->blocked = 0;
3232            }
3233            res = 0;
3234        }
3235        tipc_node_unlock(node);
3236    }
3237    read_unlock_bh(&tipc_net_lock);
3238    return res;
3239}
3240#endif
3241
3242/**
3243 * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
3244 * @dest: network address of destination node
3245 * @selector: used to select from set of active links
3246 *
3247 * If no active link can be found, uses default maximum packet size.
3248 */
3249
3250u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
3251{
3252    struct tipc_node *n_ptr;
3253    struct link *l_ptr;
3254    u32 res = MAX_PKT_DEFAULT;
3255
3256    if (dest == tipc_own_addr)
3257        return MAX_MSG_SIZE;
3258
3259    read_lock_bh(&tipc_net_lock);
3260    n_ptr = tipc_node_select(dest, selector);
3261    if (n_ptr) {
3262        tipc_node_lock(n_ptr);
3263        l_ptr = n_ptr->active_links[selector & 1];
3264        if (l_ptr)
3265            res = link_max_pkt(l_ptr);
3266        tipc_node_unlock(n_ptr);
3267    }
3268    read_unlock_bh(&tipc_net_lock);
3269    return res;
3270}
3271
3272#if 0
3273static void link_dump_rec_queue(struct link *l_ptr)
3274{
3275    struct sk_buff *crs;
3276
3277    if (!l_ptr->oldest_deferred_in) {
3278        info("Reception queue empty\n");
3279        return;
3280    }
3281    info("Contents of Reception queue:\n");
3282    crs = l_ptr->oldest_deferred_in;
3283    while (crs) {
3284        if (crs->data == (void *)0x0000a3a3) {
3285            info("buffer %x invalid\n", crs);
3286            return;
3287        }
3288        msg_dbg(buf_msg(crs), "In rec queue: \n");
3289        crs = crs->next;
3290    }
3291}
3292#endif
3293
3294static void link_dump_send_queue(struct link *l_ptr)
3295{
3296    if (l_ptr->next_out) {
3297        info("\nContents of unsent queue:\n");
3298        dbg_print_buf_chain(l_ptr->next_out);
3299    }
3300    info("\nContents of send queue:\n");
3301    if (l_ptr->first_out) {
3302        dbg_print_buf_chain(l_ptr->first_out);
3303    }
3304    info("Empty send queue\n");
3305}
3306
3307static void link_print(struct link *l_ptr, struct print_buf *buf,
3308               const char *str)
3309{
3310    tipc_printf(buf, str);
3311    if (link_reset_reset(l_ptr) || link_reset_unknown(l_ptr))
3312        return;
3313    tipc_printf(buf, "Link %x<%s>:",
3314            l_ptr->addr, l_ptr->b_ptr->publ.name);
3315    tipc_printf(buf, ": NXO(%u):", mod(l_ptr->next_out_no));
3316    tipc_printf(buf, "NXI(%u):", mod(l_ptr->next_in_no));
3317    tipc_printf(buf, "SQUE");
3318    if (l_ptr->first_out) {
3319        tipc_printf(buf, "[%u..", msg_seqno(buf_msg(l_ptr->first_out)));
3320        if (l_ptr->next_out)
3321            tipc_printf(buf, "%u..",
3322                    msg_seqno(buf_msg(l_ptr->next_out)));
3323        tipc_printf(buf, "%u]",
3324                msg_seqno(buf_msg
3325                      (l_ptr->last_out)), l_ptr->out_queue_size);
3326        if ((mod(msg_seqno(buf_msg(l_ptr->last_out)) -
3327             msg_seqno(buf_msg(l_ptr->first_out)))
3328             != (l_ptr->out_queue_size - 1))
3329            || (l_ptr->last_out->next != NULL)) {
3330            tipc_printf(buf, "\nSend queue inconsistency\n");
3331            tipc_printf(buf, "first_out= %x ", l_ptr->first_out);
3332            tipc_printf(buf, "next_out= %x ", l_ptr->next_out);
3333            tipc_printf(buf, "last_out= %x ", l_ptr->last_out);
3334            link_dump_send_queue(l_ptr);
3335        }
3336    } else
3337        tipc_printf(buf, "[]");
3338    tipc_printf(buf, "SQSIZ(%u)", l_ptr->out_queue_size);
3339    if (l_ptr->oldest_deferred_in) {
3340        u32 o = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
3341        u32 n = msg_seqno(buf_msg(l_ptr->newest_deferred_in));
3342        tipc_printf(buf, ":RQUE[%u..%u]", o, n);
3343        if (l_ptr->deferred_inqueue_sz != mod((n + 1) - o)) {
3344            tipc_printf(buf, ":RQSIZ(%u)",
3345                    l_ptr->deferred_inqueue_sz);
3346        }
3347    }
3348    if (link_working_unknown(l_ptr))
3349        tipc_printf(buf, ":WU");
3350    if (link_reset_reset(l_ptr))
3351        tipc_printf(buf, ":RR");
3352    if (link_reset_unknown(l_ptr))
3353        tipc_printf(buf, ":RU");
3354    if (link_working_working(l_ptr))
3355        tipc_printf(buf, ":WW");
3356    tipc_printf(buf, "\n");
3357}
3358
3359

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