]>
Commit | Line | Data |
---|---|---|
ae31c339 ACM |
1 | /* |
2 | * net/dccp/ackvec.c | |
3 | * | |
f17a37c9 GR |
4 | * An implementation of Ack Vectors for the DCCP protocol |
5 | * Copyright (c) 2007 University of Aberdeen, Scotland, UK | |
ae31c339 ACM |
6 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the | |
10 | * Free Software Foundation; version 2 of the License; | |
11 | */ | |
12 | ||
13 | #include "ackvec.h" | |
14 | #include "dccp.h" | |
15 | ||
9b07ef5d ACM |
16 | #include <linux/init.h> |
17 | #include <linux/errno.h> | |
18 | #include <linux/kernel.h> | |
ae31c339 | 19 | #include <linux/skbuff.h> |
9b07ef5d | 20 | #include <linux/slab.h> |
ae31c339 ACM |
21 | |
22 | #include <net/sock.h> | |
23 | ||
e18b890b CL |
24 | static struct kmem_cache *dccp_ackvec_slab; |
25 | static struct kmem_cache *dccp_ackvec_record_slab; | |
02bcf28c | 26 | |
f17a37c9 | 27 | struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) |
02bcf28c | 28 | { |
f17a37c9 GR |
29 | struct dccp_ackvec *av = kmem_cache_zalloc(dccp_ackvec_slab, priority); |
30 | ||
31 | if (av != NULL) { | |
b3d14bff | 32 | av->av_buf_head = av->av_buf_tail = DCCPAV_MAX_ACKVEC_LEN - 1; |
f17a37c9 GR |
33 | INIT_LIST_HEAD(&av->av_records); |
34 | } | |
35 | return av; | |
36 | } | |
02bcf28c | 37 | |
f17a37c9 GR |
38 | static void dccp_ackvec_purge_records(struct dccp_ackvec *av) |
39 | { | |
40 | struct dccp_ackvec_record *cur, *next; | |
02bcf28c | 41 | |
f17a37c9 GR |
42 | list_for_each_entry_safe(cur, next, &av->av_records, avr_node) |
43 | kmem_cache_free(dccp_ackvec_record_slab, cur); | |
44 | INIT_LIST_HEAD(&av->av_records); | |
02bcf28c AB |
45 | } |
46 | ||
f17a37c9 | 47 | void dccp_ackvec_free(struct dccp_ackvec *av) |
02bcf28c | 48 | { |
f17a37c9 GR |
49 | if (likely(av != NULL)) { |
50 | dccp_ackvec_purge_records(av); | |
51 | kmem_cache_free(dccp_ackvec_slab, av); | |
52 | } | |
02bcf28c AB |
53 | } |
54 | ||
7d870936 GR |
55 | /** |
56 | * dccp_ackvec_update_records - Record information about sent Ack Vectors | |
57 | * @av: Ack Vector records to update | |
58 | * @seqno: Sequence number of the packet carrying the Ack Vector just sent | |
59 | * @nonce_sum: The sum of all buffer nonces contained in the Ack Vector | |
60 | */ | |
61 | int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum) | |
ae31c339 | 62 | { |
02bcf28c AB |
63 | struct dccp_ackvec_record *avr; |
64 | ||
f17a37c9 | 65 | avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); |
2d0817d1 | 66 | if (avr == NULL) |
7d870936 | 67 | return -ENOBUFS; |
ae31c339 | 68 | |
7d870936 | 69 | avr->avr_ack_seqno = seqno; |
f17a37c9 GR |
70 | avr->avr_ack_ptr = av->av_buf_head; |
71 | avr->avr_ack_ackno = av->av_buf_ackno; | |
7d870936 | 72 | avr->avr_ack_nonce = nonce_sum; |
f17a37c9 | 73 | avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head); |
b3d14bff GR |
74 | /* |
75 | * When the buffer overflows, we keep no more than one record. This is | |
76 | * the simplest way of disambiguating sender-Acks dating from before the | |
77 | * overflow from sender-Acks which refer to after the overflow; a simple | |
78 | * solution is preferable here since we are handling an exception. | |
79 | */ | |
80 | if (av->av_overflow) | |
81 | dccp_ackvec_purge_records(av); | |
7d870936 GR |
82 | /* |
83 | * Since GSS is incremented for each packet, the list is automatically | |
84 | * arranged in descending order of @ack_seqno. | |
85 | */ | |
86 | list_add(&avr->avr_node, &av->av_records); | |
02bcf28c | 87 | |
7d870936 | 88 | dccp_pr_debug("Added Vector, ack_seqno=%llu, ack_ackno=%llu (rl=%u)\n", |
a47c5104 | 89 | (unsigned long long)avr->avr_ack_seqno, |
7d870936 GR |
90 | (unsigned long long)avr->avr_ack_ackno, |
91 | avr->avr_ack_runlen); | |
02bcf28c | 92 | return 0; |
ae31c339 ACM |
93 | } |
94 | ||
5753fdfe GR |
95 | static struct dccp_ackvec_record *dccp_ackvec_lookup(struct list_head *av_list, |
96 | const u64 ackno) | |
97 | { | |
98 | struct dccp_ackvec_record *avr; | |
99 | /* | |
100 | * Exploit that records are inserted in descending order of sequence | |
101 | * number, start with the oldest record first. If @ackno is `before' | |
102 | * the earliest ack_ackno, the packet is too old to be considered. | |
103 | */ | |
104 | list_for_each_entry_reverse(avr, av_list, avr_node) { | |
105 | if (avr->avr_ack_seqno == ackno) | |
106 | return avr; | |
107 | if (before48(ackno, avr->avr_ack_seqno)) | |
108 | break; | |
109 | } | |
110 | return NULL; | |
111 | } | |
112 | ||
b3d14bff GR |
113 | /* |
114 | * Buffer index and length computation using modulo-buffersize arithmetic. | |
115 | * Note that, as pointers move from right to left, head is `before' tail. | |
116 | */ | |
117 | static inline u16 __ackvec_idx_add(const u16 a, const u16 b) | |
118 | { | |
119 | return (a + b) % DCCPAV_MAX_ACKVEC_LEN; | |
120 | } | |
121 | ||
122 | static inline u16 __ackvec_idx_sub(const u16 a, const u16 b) | |
123 | { | |
124 | return __ackvec_idx_add(a, DCCPAV_MAX_ACKVEC_LEN - b); | |
125 | } | |
126 | ||
127 | u16 dccp_ackvec_buflen(const struct dccp_ackvec *av) | |
128 | { | |
129 | if (unlikely(av->av_overflow)) | |
130 | return DCCPAV_MAX_ACKVEC_LEN; | |
131 | return __ackvec_idx_sub(av->av_buf_tail, av->av_buf_head); | |
132 | } | |
133 | ||
ae31c339 ACM |
134 | /* |
135 | * If several packets are missing, the HC-Receiver may prefer to enter multiple | |
136 | * bytes with run length 0, rather than a single byte with a larger run length; | |
137 | * this simplifies table updates if one of the missing packets arrives. | |
138 | */ | |
139 | static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, | |
140 | const unsigned int packets, | |
e4dfd449 | 141 | const unsigned char state) |
ae31c339 | 142 | { |
8e64159d | 143 | long gap; |
a8fc3d8d | 144 | long new_head; |
ae31c339 | 145 | |
f17a37c9 | 146 | if (av->av_vec_len + packets > DCCPAV_MAX_ACKVEC_LEN) |
ae31c339 ACM |
147 | return -ENOBUFS; |
148 | ||
149 | gap = packets - 1; | |
a47c5104 | 150 | new_head = av->av_buf_head - packets; |
ae31c339 ACM |
151 | |
152 | if (new_head < 0) { | |
153 | if (gap > 0) { | |
f17a37c9 | 154 | memset(av->av_buf, DCCPAV_NOT_RECEIVED, |
ae31c339 ACM |
155 | gap + new_head + 1); |
156 | gap = -new_head; | |
157 | } | |
f17a37c9 | 158 | new_head += DCCPAV_MAX_ACKVEC_LEN; |
8109b02b | 159 | } |
ae31c339 | 160 | |
a47c5104 | 161 | av->av_buf_head = new_head; |
ae31c339 ACM |
162 | |
163 | if (gap > 0) | |
a47c5104 | 164 | memset(av->av_buf + av->av_buf_head + 1, |
f17a37c9 | 165 | DCCPAV_NOT_RECEIVED, gap); |
ae31c339 | 166 | |
a47c5104 GR |
167 | av->av_buf[av->av_buf_head] = state; |
168 | av->av_vec_len += packets; | |
ae31c339 ACM |
169 | return 0; |
170 | } | |
171 | ||
172 | /* | |
0e64e94e | 173 | * Implements the RFC 4340, Appendix A |
ae31c339 ACM |
174 | */ |
175 | int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, | |
176 | const u64 ackno, const u8 state) | |
177 | { | |
f17a37c9 GR |
178 | u8 *cur_head = av->av_buf + av->av_buf_head, |
179 | *buf_end = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; | |
ae31c339 ACM |
180 | /* |
181 | * Check at the right places if the buffer is full, if it is, tell the | |
182 | * caller to start dropping packets till the HC-Sender acks our ACK | |
a47c5104 | 183 | * vectors, when we will free up space in av_buf. |
ae31c339 ACM |
184 | * |
185 | * We may well decide to do buffer compression, etc, but for now lets | |
186 | * just drop. | |
187 | * | |
0e64e94e | 188 | * From Appendix A.1.1 (`New Packets'): |
ae31c339 ACM |
189 | * |
190 | * Of course, the circular buffer may overflow, either when the | |
191 | * HC-Sender is sending data at a very high rate, when the | |
192 | * HC-Receiver's acknowledgements are not reaching the HC-Sender, | |
193 | * or when the HC-Sender is forgetting to acknowledge those acks | |
194 | * (so the HC-Receiver is unable to clean up old state). In this | |
195 | * case, the HC-Receiver should either compress the buffer (by | |
196 | * increasing run lengths when possible), transfer its state to | |
197 | * a larger buffer, or, as a last resort, drop all received | |
198 | * packets, without processing them whatsoever, until its buffer | |
199 | * shrinks again. | |
200 | */ | |
201 | ||
202 | /* See if this is the first ackno being inserted */ | |
a47c5104 | 203 | if (av->av_vec_len == 0) { |
f17a37c9 | 204 | *cur_head = state; |
a47c5104 GR |
205 | av->av_vec_len = 1; |
206 | } else if (after48(ackno, av->av_buf_ackno)) { | |
207 | const u64 delta = dccp_delta_seqno(av->av_buf_ackno, ackno); | |
ae31c339 ACM |
208 | |
209 | /* | |
210 | * Look if the state of this packet is the same as the | |
211 | * previous ackno and if so if we can bump the head len. | |
212 | */ | |
f17a37c9 GR |
213 | if (delta == 1 && dccp_ackvec_state(cur_head) == state && |
214 | dccp_ackvec_runlen(cur_head) < DCCPAV_MAX_RUNLEN) | |
215 | *cur_head += 1; | |
ae31c339 ACM |
216 | else if (dccp_ackvec_set_buf_head_state(av, delta, state)) |
217 | return -ENOBUFS; | |
218 | } else { | |
219 | /* | |
220 | * A.1.2. Old Packets | |
221 | * | |
0e64e94e GR |
222 | * When a packet with Sequence Number S <= buf_ackno |
223 | * arrives, the HC-Receiver will scan the table for | |
224 | * the byte corresponding to S. (Indexing structures | |
ae31c339 ACM |
225 | * could reduce the complexity of this scan.) |
226 | */ | |
a47c5104 | 227 | u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno); |
ae31c339 ACM |
228 | |
229 | while (1) { | |
f17a37c9 | 230 | const u8 len = dccp_ackvec_runlen(cur_head); |
ae31c339 | 231 | /* |
a47c5104 | 232 | * valid packets not yet in av_buf have a reserved |
ae31c339 ACM |
233 | * entry, with a len equal to 0. |
234 | */ | |
f17a37c9 | 235 | if (*cur_head == DCCPAV_NOT_RECEIVED && delta == 0) { |
ae31c339 ACM |
236 | dccp_pr_debug("Found %llu reserved seat!\n", |
237 | (unsigned long long)ackno); | |
f17a37c9 | 238 | *cur_head = state; |
ae31c339 ACM |
239 | goto out; |
240 | } | |
241 | /* len == 0 means one packet */ | |
242 | if (delta < len + 1) | |
243 | goto out_duplicate; | |
244 | ||
245 | delta -= len + 1; | |
f17a37c9 GR |
246 | if (++cur_head == buf_end) |
247 | cur_head = av->av_buf; | |
ae31c339 ACM |
248 | } |
249 | } | |
250 | ||
a47c5104 | 251 | av->av_buf_ackno = ackno; |
ae31c339 | 252 | out: |
ae31c339 ACM |
253 | return 0; |
254 | ||
255 | out_duplicate: | |
256 | /* Duplicate packet */ | |
257 | dccp_pr_debug("Received a dup or already considered lost " | |
258 | "packet: %llu\n", (unsigned long long)ackno); | |
259 | return -EILSEQ; | |
260 | } | |
261 | ||
02bcf28c AB |
262 | static void dccp_ackvec_throw_record(struct dccp_ackvec *av, |
263 | struct dccp_ackvec_record *avr) | |
ae31c339 | 264 | { |
02bcf28c AB |
265 | struct dccp_ackvec_record *next; |
266 | ||
23d06e3b | 267 | /* sort out vector length */ |
a47c5104 GR |
268 | if (av->av_buf_head <= avr->avr_ack_ptr) |
269 | av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head; | |
23d06e3b | 270 | else |
f17a37c9 | 271 | av->av_vec_len = DCCPAV_MAX_ACKVEC_LEN - 1 - |
a47c5104 | 272 | av->av_buf_head + avr->avr_ack_ptr; |
02bcf28c AB |
273 | |
274 | /* free records */ | |
a47c5104 | 275 | list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { |
f17a37c9 GR |
276 | list_del(&avr->avr_node); |
277 | kmem_cache_free(dccp_ackvec_record_slab, avr); | |
02bcf28c | 278 | } |
ae31c339 ACM |
279 | } |
280 | ||
281 | void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, | |
282 | const u64 ackno) | |
283 | { | |
02bcf28c | 284 | struct dccp_ackvec_record *avr; |
ae31c339 | 285 | |
02bcf28c AB |
286 | /* |
287 | * If we traverse backwards, it should be faster when we have large | |
288 | * windows. We will be receiving ACKs for stuff we sent a while back | |
289 | * -sorbo. | |
290 | */ | |
a47c5104 GR |
291 | list_for_each_entry_reverse(avr, &av->av_records, avr_node) { |
292 | if (ackno == avr->avr_ack_seqno) { | |
09dbc389 | 293 | dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, " |
02bcf28c | 294 | "ack_ackno=%llu, ACKED!\n", |
f17a37c9 | 295 | dccp_role(sk), avr->avr_ack_runlen, |
a47c5104 GR |
296 | (unsigned long long)avr->avr_ack_seqno, |
297 | (unsigned long long)avr->avr_ack_ackno); | |
02bcf28c AB |
298 | dccp_ackvec_throw_record(av, avr); |
299 | break; | |
a47c5104 | 300 | } else if (avr->avr_ack_seqno > ackno) |
d23ca15a | 301 | break; /* old news */ |
ae31c339 ACM |
302 | } |
303 | } | |
304 | ||
305 | static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, | |
bdf13d20 | 306 | struct sock *sk, u64 *ackno, |
ae31c339 ACM |
307 | const unsigned char len, |
308 | const unsigned char *vector) | |
309 | { | |
310 | unsigned char i; | |
02bcf28c | 311 | struct dccp_ackvec_record *avr; |
ae31c339 ACM |
312 | |
313 | /* Check if we actually sent an ACK vector */ | |
a47c5104 | 314 | if (list_empty(&av->av_records)) |
ae31c339 | 315 | return; |
ae31c339 ACM |
316 | |
317 | i = len; | |
02bcf28c AB |
318 | /* |
319 | * XXX | |
320 | * I think it might be more efficient to work backwards. See comment on | |
321 | * rcv_ackno. -sorbo. | |
322 | */ | |
a47c5104 | 323 | avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node); |
ae31c339 | 324 | while (i--) { |
f17a37c9 | 325 | const u8 rl = dccp_ackvec_runlen(vector); |
ae31c339 ACM |
326 | u64 ackno_end_rl; |
327 | ||
bdf13d20 | 328 | dccp_set_seqno(&ackno_end_rl, *ackno - rl); |
ae31c339 ACM |
329 | |
330 | /* | |
02bcf28c AB |
331 | * If our AVR sequence number is greater than the ack, go |
332 | * forward in the AVR list until it is not so. | |
ae31c339 | 333 | */ |
a47c5104 GR |
334 | list_for_each_entry_from(avr, &av->av_records, avr_node) { |
335 | if (!after48(avr->avr_ack_seqno, *ackno)) | |
02bcf28c AB |
336 | goto found; |
337 | } | |
a47c5104 | 338 | /* End of the av_records list, not found, exit */ |
02bcf28c AB |
339 | break; |
340 | found: | |
a47c5104 | 341 | if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) { |
f17a37c9 | 342 | if (dccp_ackvec_state(vector) != DCCPAV_NOT_RECEIVED) { |
09dbc389 | 343 | dccp_pr_debug("%s ACK vector 0, len=%d, " |
ae31c339 ACM |
344 | "ack_seqno=%llu, ack_ackno=%llu, " |
345 | "ACKED!\n", | |
09dbc389 | 346 | dccp_role(sk), len, |
ae31c339 | 347 | (unsigned long long) |
a47c5104 | 348 | avr->avr_ack_seqno, |
ae31c339 | 349 | (unsigned long long) |
a47c5104 | 350 | avr->avr_ack_ackno); |
02bcf28c | 351 | dccp_ackvec_throw_record(av, avr); |
afec35e3 | 352 | break; |
ae31c339 ACM |
353 | } |
354 | /* | |
02bcf28c AB |
355 | * If it wasn't received, continue scanning... we might |
356 | * find another one. | |
ae31c339 | 357 | */ |
ae31c339 | 358 | } |
ae31c339 | 359 | |
bdf13d20 | 360 | dccp_set_seqno(ackno, ackno_end_rl - 1); |
ae31c339 ACM |
361 | ++vector; |
362 | } | |
363 | } | |
364 | ||
365 | int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, | |
bdf13d20 | 366 | u64 *ackno, const u8 opt, const u8 *value, const u8 len) |
ae31c339 | 367 | { |
b20a9c24 | 368 | if (len > DCCP_SINGLE_OPT_MAXLEN) |
ae31c339 ACM |
369 | return -1; |
370 | ||
371 | /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */ | |
372 | dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk, | |
bdf13d20 | 373 | ackno, len, value); |
ae31c339 ACM |
374 | return 0; |
375 | } | |
9b07ef5d | 376 | |
5753fdfe GR |
377 | /** |
378 | * dccp_ackvec_clear_state - Perform house-keeping / garbage-collection | |
379 | * This routine is called when the peer acknowledges the receipt of Ack Vectors | |
380 | * up to and including @ackno. While based on on section A.3 of RFC 4340, here | |
381 | * are additional precautions to prevent corrupted buffer state. In particular, | |
382 | * we use tail_ackno to identify outdated records; it always marks the earliest | |
383 | * packet of group (2) in 11.4.2. | |
384 | */ | |
385 | void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno) | |
386 | { | |
387 | struct dccp_ackvec_record *avr, *next; | |
388 | u8 runlen_now, eff_runlen; | |
389 | s64 delta; | |
390 | ||
391 | avr = dccp_ackvec_lookup(&av->av_records, ackno); | |
392 | if (avr == NULL) | |
393 | return; | |
394 | /* | |
395 | * Deal with outdated acknowledgments: this arises when e.g. there are | |
396 | * several old records and the acks from the peer come in slowly. In | |
397 | * that case we may still have records that pre-date tail_ackno. | |
398 | */ | |
399 | delta = dccp_delta_seqno(av->av_tail_ackno, avr->avr_ack_ackno); | |
400 | if (delta < 0) | |
401 | goto free_records; | |
402 | /* | |
403 | * Deal with overlapping Ack Vectors: don't subtract more than the | |
404 | * number of packets between tail_ackno and ack_ackno. | |
405 | */ | |
406 | eff_runlen = delta < avr->avr_ack_runlen ? delta : avr->avr_ack_runlen; | |
407 | ||
408 | runlen_now = dccp_ackvec_runlen(av->av_buf + avr->avr_ack_ptr); | |
409 | /* | |
410 | * The run length of Ack Vector cells does not decrease over time. If | |
411 | * the run length is the same as at the time the Ack Vector was sent, we | |
412 | * free the ack_ptr cell. That cell can however not be freed if the run | |
413 | * length has increased: in this case we need to move the tail pointer | |
414 | * backwards (towards higher indices), to its next-oldest neighbour. | |
415 | */ | |
416 | if (runlen_now > eff_runlen) { | |
417 | ||
418 | av->av_buf[avr->avr_ack_ptr] -= eff_runlen + 1; | |
419 | av->av_buf_tail = __ackvec_idx_add(avr->avr_ack_ptr, 1); | |
420 | ||
421 | /* This move may not have cleared the overflow flag. */ | |
422 | if (av->av_overflow) | |
423 | av->av_overflow = (av->av_buf_head == av->av_buf_tail); | |
424 | } else { | |
425 | av->av_buf_tail = avr->avr_ack_ptr; | |
426 | /* | |
427 | * We have made sure that avr points to a valid cell within the | |
428 | * buffer. This cell is either older than head, or equals head | |
429 | * (empty buffer): in both cases we no longer have any overflow. | |
430 | */ | |
431 | av->av_overflow = 0; | |
432 | } | |
433 | ||
434 | /* | |
435 | * The peer has acknowledged up to and including ack_ackno. Hence the | |
436 | * first packet in group (2) of 11.4.2 is the successor of ack_ackno. | |
437 | */ | |
438 | av->av_tail_ackno = ADD48(avr->avr_ack_ackno, 1); | |
439 | ||
440 | free_records: | |
441 | list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { | |
442 | list_del(&avr->avr_node); | |
443 | kmem_cache_free(dccp_ackvec_record_slab, avr); | |
444 | } | |
445 | } | |
446 | ||
9b07ef5d ACM |
447 | int __init dccp_ackvec_init(void) |
448 | { | |
449 | dccp_ackvec_slab = kmem_cache_create("dccp_ackvec", | |
450 | sizeof(struct dccp_ackvec), 0, | |
20c2df83 | 451 | SLAB_HWCACHE_ALIGN, NULL); |
02bcf28c AB |
452 | if (dccp_ackvec_slab == NULL) |
453 | goto out_err; | |
454 | ||
f17a37c9 GR |
455 | dccp_ackvec_record_slab = kmem_cache_create("dccp_ackvec_record", |
456 | sizeof(struct dccp_ackvec_record), | |
457 | 0, SLAB_HWCACHE_ALIGN, NULL); | |
02bcf28c AB |
458 | if (dccp_ackvec_record_slab == NULL) |
459 | goto out_destroy_slab; | |
9b07ef5d ACM |
460 | |
461 | return 0; | |
02bcf28c AB |
462 | |
463 | out_destroy_slab: | |
464 | kmem_cache_destroy(dccp_ackvec_slab); | |
465 | dccp_ackvec_slab = NULL; | |
466 | out_err: | |
59348b19 | 467 | DCCP_CRIT("Unable to create Ack Vector slab cache"); |
02bcf28c | 468 | return -ENOBUFS; |
9b07ef5d ACM |
469 | } |
470 | ||
471 | void dccp_ackvec_exit(void) | |
472 | { | |
473 | if (dccp_ackvec_slab != NULL) { | |
474 | kmem_cache_destroy(dccp_ackvec_slab); | |
475 | dccp_ackvec_slab = NULL; | |
476 | } | |
02bcf28c AB |
477 | if (dccp_ackvec_record_slab != NULL) { |
478 | kmem_cache_destroy(dccp_ackvec_record_slab); | |
479 | dccp_ackvec_record_slab = NULL; | |
480 | } | |
9b07ef5d | 481 | } |