Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/dccp/ackvec.c |
| 3 | * |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 4 | * An implementation of Ack Vectors for the DCCP protocol |
| 5 | * Copyright (c) 2007 University of Aberdeen, Scotland, UK |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 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 | |
Arnaldo Carvalho de Melo | 9b07ef5 | 2006-03-20 17:16:17 -0800 | [diff] [blame] | 16 | #include <linux/init.h> |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/kernel.h> |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 19 | #include <linux/skbuff.h> |
Arnaldo Carvalho de Melo | 9b07ef5 | 2006-03-20 17:16:17 -0800 | [diff] [blame] | 20 | #include <linux/slab.h> |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 21 | |
| 22 | #include <net/sock.h> |
| 23 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 24 | static struct kmem_cache *dccp_ackvec_slab; |
| 25 | static struct kmem_cache *dccp_ackvec_record_slab; |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 26 | |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 27 | struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 28 | { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 29 | struct dccp_ackvec *av = kmem_cache_zalloc(dccp_ackvec_slab, priority); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 30 | |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 31 | if (av != NULL) { |
Gerrit Renker | b3d14bf | 2010-11-10 21:21:35 +0100 | [diff] [blame] | 32 | av->av_buf_head = av->av_buf_tail = DCCPAV_MAX_ACKVEC_LEN - 1; |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 33 | INIT_LIST_HEAD(&av->av_records); |
| 34 | } |
| 35 | return av; |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 36 | } |
| 37 | |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 38 | static void dccp_ackvec_purge_records(struct dccp_ackvec *av) |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 39 | { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 40 | struct dccp_ackvec_record *cur, *next; |
| 41 | |
| 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); |
| 45 | } |
| 46 | |
| 47 | void dccp_ackvec_free(struct dccp_ackvec *av) |
| 48 | { |
| 49 | if (likely(av != NULL)) { |
| 50 | dccp_ackvec_purge_records(av); |
| 51 | kmem_cache_free(dccp_ackvec_slab, av); |
| 52 | } |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 53 | } |
| 54 | |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 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) |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 62 | { |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 63 | struct dccp_ackvec_record *avr; |
| 64 | |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 65 | avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); |
Arnaldo Carvalho de Melo | 2d0817d | 2006-03-20 22:32:06 -0800 | [diff] [blame] | 66 | if (avr == NULL) |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 67 | return -ENOBUFS; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 68 | |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 69 | avr->avr_ack_seqno = seqno; |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 70 | avr->avr_ack_ptr = av->av_buf_head; |
| 71 | avr->avr_ack_ackno = av->av_buf_ackno; |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 72 | avr->avr_ack_nonce = nonce_sum; |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 73 | avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head); |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 74 | /* |
Gerrit Renker | b3d14bf | 2010-11-10 21:21:35 +0100 | [diff] [blame] | 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); |
| 82 | /* |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 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); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 87 | |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 88 | dccp_pr_debug("Added Vector, ack_seqno=%llu, ack_ackno=%llu (rl=%u)\n", |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 89 | (unsigned long long)avr->avr_ack_seqno, |
Gerrit Renker | 7d87093 | 2010-11-10 21:21:02 +0100 | [diff] [blame] | 90 | (unsigned long long)avr->avr_ack_ackno, |
| 91 | avr->avr_ack_runlen); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 92 | return 0; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 93 | } |
| 94 | |
Gerrit Renker | 5753fdf | 2010-11-14 17:25:11 +0100 | [diff] [blame] | 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 | |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 113 | /* |
Gerrit Renker | b3d14bf | 2010-11-10 21:21:35 +0100 | [diff] [blame] | 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 | |
Gerrit Renker | 3802408 | 2010-11-14 17:25:23 +0100 | [diff] [blame^] | 134 | /** |
| 135 | * dccp_ackvec_update_old - Update previous state as per RFC 4340, 11.4.1 |
| 136 | * @av: non-empty buffer to update |
| 137 | * @distance: negative or zero distance of @seqno from buf_ackno downward |
| 138 | * @seqno: the (old) sequence number whose record is to be updated |
| 139 | * @state: state in which packet carrying @seqno was received |
| 140 | */ |
| 141 | static void dccp_ackvec_update_old(struct dccp_ackvec *av, s64 distance, |
| 142 | u64 seqno, enum dccp_ackvec_states state) |
| 143 | { |
| 144 | u16 ptr = av->av_buf_head; |
| 145 | |
| 146 | BUG_ON(distance > 0); |
| 147 | if (unlikely(dccp_ackvec_is_empty(av))) |
| 148 | return; |
| 149 | |
| 150 | do { |
| 151 | u8 runlen = dccp_ackvec_runlen(av->av_buf + ptr); |
| 152 | |
| 153 | if (distance + runlen >= 0) { |
| 154 | /* |
| 155 | * Only update the state if packet has not been received |
| 156 | * yet. This is OK as per the second table in RFC 4340, |
| 157 | * 11.4.1; i.e. here we are using the following table: |
| 158 | * RECEIVED |
| 159 | * 0 1 3 |
| 160 | * S +---+---+---+ |
| 161 | * T 0 | 0 | 0 | 0 | |
| 162 | * O +---+---+---+ |
| 163 | * R 1 | 1 | 1 | 1 | |
| 164 | * E +---+---+---+ |
| 165 | * D 3 | 0 | 1 | 3 | |
| 166 | * +---+---+---+ |
| 167 | * The "Not Received" state was set by reserve_seats(). |
| 168 | */ |
| 169 | if (av->av_buf[ptr] == DCCPAV_NOT_RECEIVED) |
| 170 | av->av_buf[ptr] = state; |
| 171 | else |
| 172 | dccp_pr_debug("Not changing %llu state to %u\n", |
| 173 | (unsigned long long)seqno, state); |
| 174 | break; |
| 175 | } |
| 176 | |
| 177 | distance += runlen + 1; |
| 178 | ptr = __ackvec_idx_add(ptr, 1); |
| 179 | |
| 180 | } while (ptr != av->av_buf_tail); |
| 181 | } |
| 182 | |
| 183 | /* Mark @num entries after buf_head as "Not yet received". */ |
| 184 | static void dccp_ackvec_reserve_seats(struct dccp_ackvec *av, u16 num) |
| 185 | { |
| 186 | u16 start = __ackvec_idx_add(av->av_buf_head, 1), |
| 187 | len = DCCPAV_MAX_ACKVEC_LEN - start; |
| 188 | |
| 189 | /* check for buffer wrap-around */ |
| 190 | if (num > len) { |
| 191 | memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, len); |
| 192 | start = 0; |
| 193 | num -= len; |
| 194 | } |
| 195 | if (num) |
| 196 | memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, num); |
| 197 | } |
| 198 | |
| 199 | /** |
| 200 | * dccp_ackvec_add_new - Record one or more new entries in Ack Vector buffer |
| 201 | * @av: container of buffer to update (can be empty or non-empty) |
| 202 | * @num_packets: number of packets to register (must be >= 1) |
| 203 | * @seqno: sequence number of the first packet in @num_packets |
| 204 | * @state: state in which packet carrying @seqno was received |
| 205 | */ |
| 206 | static void dccp_ackvec_add_new(struct dccp_ackvec *av, u32 num_packets, |
| 207 | u64 seqno, enum dccp_ackvec_states state) |
| 208 | { |
| 209 | u32 num_cells = num_packets; |
| 210 | |
| 211 | if (num_packets > DCCPAV_BURST_THRESH) { |
| 212 | u32 lost_packets = num_packets - 1; |
| 213 | |
| 214 | DCCP_WARN("Warning: large burst loss (%u)\n", lost_packets); |
| 215 | /* |
| 216 | * We received 1 packet and have a loss of size "num_packets-1" |
| 217 | * which we squeeze into num_cells-1 rather than reserving an |
| 218 | * entire byte for each lost packet. |
| 219 | * The reason is that the vector grows in O(burst_length); when |
| 220 | * it grows too large there will no room left for the payload. |
| 221 | * This is a trade-off: if a few packets out of the burst show |
| 222 | * up later, their state will not be changed; it is simply too |
| 223 | * costly to reshuffle/reallocate/copy the buffer each time. |
| 224 | * Should such problems persist, we will need to switch to a |
| 225 | * different underlying data structure. |
| 226 | */ |
| 227 | for (num_packets = num_cells = 1; lost_packets; ++num_cells) { |
| 228 | u8 len = min(lost_packets, (u32)DCCPAV_MAX_RUNLEN); |
| 229 | |
| 230 | av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, 1); |
| 231 | av->av_buf[av->av_buf_head] = DCCPAV_NOT_RECEIVED | len; |
| 232 | |
| 233 | lost_packets -= len; |
| 234 | } |
| 235 | } |
| 236 | |
| 237 | if (num_cells + dccp_ackvec_buflen(av) >= DCCPAV_MAX_ACKVEC_LEN) { |
| 238 | DCCP_CRIT("Ack Vector buffer overflow: dropping old entries\n"); |
| 239 | av->av_overflow = true; |
| 240 | } |
| 241 | |
| 242 | av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, num_packets); |
| 243 | if (av->av_overflow) |
| 244 | av->av_buf_tail = av->av_buf_head; |
| 245 | |
| 246 | av->av_buf[av->av_buf_head] = state; |
| 247 | av->av_buf_ackno = seqno; |
| 248 | |
| 249 | if (num_packets > 1) |
| 250 | dccp_ackvec_reserve_seats(av, num_packets - 1); |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * dccp_ackvec_input - Register incoming packet in the buffer |
| 255 | */ |
| 256 | void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb) |
| 257 | { |
| 258 | u64 seqno = DCCP_SKB_CB(skb)->dccpd_seq; |
| 259 | enum dccp_ackvec_states state = DCCPAV_RECEIVED; |
| 260 | |
| 261 | if (dccp_ackvec_is_empty(av)) { |
| 262 | dccp_ackvec_add_new(av, 1, seqno, state); |
| 263 | av->av_tail_ackno = seqno; |
| 264 | |
| 265 | } else { |
| 266 | s64 num_packets = dccp_delta_seqno(av->av_buf_ackno, seqno); |
| 267 | u8 *current_head = av->av_buf + av->av_buf_head; |
| 268 | |
| 269 | if (num_packets == 1 && |
| 270 | dccp_ackvec_state(current_head) == state && |
| 271 | dccp_ackvec_runlen(current_head) < DCCPAV_MAX_RUNLEN) { |
| 272 | |
| 273 | *current_head += 1; |
| 274 | av->av_buf_ackno = seqno; |
| 275 | |
| 276 | } else if (num_packets > 0) { |
| 277 | dccp_ackvec_add_new(av, num_packets, seqno, state); |
| 278 | } else { |
| 279 | dccp_ackvec_update_old(av, num_packets, seqno, state); |
| 280 | } |
| 281 | } |
| 282 | } |
| 283 | |
Gerrit Renker | b3d14bf | 2010-11-10 21:21:35 +0100 | [diff] [blame] | 284 | /* |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 285 | * If several packets are missing, the HC-Receiver may prefer to enter multiple |
| 286 | * bytes with run length 0, rather than a single byte with a larger run length; |
| 287 | * this simplifies table updates if one of the missing packets arrives. |
| 288 | */ |
| 289 | static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, |
| 290 | const unsigned int packets, |
Arnaldo Carvalho de Melo | e4dfd44 | 2006-01-04 01:46:34 -0200 | [diff] [blame] | 291 | const unsigned char state) |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 292 | { |
Kulikov Vasiliy | 8e64159 | 2010-07-17 05:21:00 +0000 | [diff] [blame] | 293 | long gap; |
Kris Katterjohn | a8fc3d8 | 2006-01-17 13:03:54 -0800 | [diff] [blame] | 294 | long new_head; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 295 | |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 296 | if (av->av_vec_len + packets > DCCPAV_MAX_ACKVEC_LEN) |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 297 | return -ENOBUFS; |
| 298 | |
| 299 | gap = packets - 1; |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 300 | new_head = av->av_buf_head - packets; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 301 | |
| 302 | if (new_head < 0) { |
| 303 | if (gap > 0) { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 304 | memset(av->av_buf, DCCPAV_NOT_RECEIVED, |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 305 | gap + new_head + 1); |
| 306 | gap = -new_head; |
| 307 | } |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 308 | new_head += DCCPAV_MAX_ACKVEC_LEN; |
Arnaldo Carvalho de Melo | 8109b02 | 2006-12-10 16:01:18 -0200 | [diff] [blame] | 309 | } |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 310 | |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 311 | av->av_buf_head = new_head; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 312 | |
| 313 | if (gap > 0) |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 314 | memset(av->av_buf + av->av_buf_head + 1, |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 315 | DCCPAV_NOT_RECEIVED, gap); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 316 | |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 317 | av->av_buf[av->av_buf_head] = state; |
| 318 | av->av_vec_len += packets; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 319 | return 0; |
| 320 | } |
| 321 | |
| 322 | /* |
Gerrit Renker | 0e64e94 | 2006-10-24 16:17:51 -0700 | [diff] [blame] | 323 | * Implements the RFC 4340, Appendix A |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 324 | */ |
| 325 | int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, |
| 326 | const u64 ackno, const u8 state) |
| 327 | { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 328 | u8 *cur_head = av->av_buf + av->av_buf_head, |
| 329 | *buf_end = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 330 | /* |
| 331 | * Check at the right places if the buffer is full, if it is, tell the |
| 332 | * caller to start dropping packets till the HC-Sender acks our ACK |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 333 | * vectors, when we will free up space in av_buf. |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 334 | * |
| 335 | * We may well decide to do buffer compression, etc, but for now lets |
| 336 | * just drop. |
| 337 | * |
Gerrit Renker | 0e64e94 | 2006-10-24 16:17:51 -0700 | [diff] [blame] | 338 | * From Appendix A.1.1 (`New Packets'): |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 339 | * |
| 340 | * Of course, the circular buffer may overflow, either when the |
| 341 | * HC-Sender is sending data at a very high rate, when the |
| 342 | * HC-Receiver's acknowledgements are not reaching the HC-Sender, |
| 343 | * or when the HC-Sender is forgetting to acknowledge those acks |
| 344 | * (so the HC-Receiver is unable to clean up old state). In this |
| 345 | * case, the HC-Receiver should either compress the buffer (by |
| 346 | * increasing run lengths when possible), transfer its state to |
| 347 | * a larger buffer, or, as a last resort, drop all received |
| 348 | * packets, without processing them whatsoever, until its buffer |
| 349 | * shrinks again. |
| 350 | */ |
| 351 | |
| 352 | /* See if this is the first ackno being inserted */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 353 | if (av->av_vec_len == 0) { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 354 | *cur_head = state; |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 355 | av->av_vec_len = 1; |
| 356 | } else if (after48(ackno, av->av_buf_ackno)) { |
| 357 | const u64 delta = dccp_delta_seqno(av->av_buf_ackno, ackno); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 358 | |
| 359 | /* |
| 360 | * Look if the state of this packet is the same as the |
| 361 | * previous ackno and if so if we can bump the head len. |
| 362 | */ |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 363 | if (delta == 1 && dccp_ackvec_state(cur_head) == state && |
| 364 | dccp_ackvec_runlen(cur_head) < DCCPAV_MAX_RUNLEN) |
| 365 | *cur_head += 1; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 366 | else if (dccp_ackvec_set_buf_head_state(av, delta, state)) |
| 367 | return -ENOBUFS; |
| 368 | } else { |
| 369 | /* |
| 370 | * A.1.2. Old Packets |
| 371 | * |
Gerrit Renker | 0e64e94 | 2006-10-24 16:17:51 -0700 | [diff] [blame] | 372 | * When a packet with Sequence Number S <= buf_ackno |
| 373 | * arrives, the HC-Receiver will scan the table for |
| 374 | * the byte corresponding to S. (Indexing structures |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 375 | * could reduce the complexity of this scan.) |
| 376 | */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 377 | u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 378 | |
| 379 | while (1) { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 380 | const u8 len = dccp_ackvec_runlen(cur_head); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 381 | /* |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 382 | * valid packets not yet in av_buf have a reserved |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 383 | * entry, with a len equal to 0. |
| 384 | */ |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 385 | if (*cur_head == DCCPAV_NOT_RECEIVED && delta == 0) { |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 386 | dccp_pr_debug("Found %llu reserved seat!\n", |
| 387 | (unsigned long long)ackno); |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 388 | *cur_head = state; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 389 | goto out; |
| 390 | } |
| 391 | /* len == 0 means one packet */ |
| 392 | if (delta < len + 1) |
| 393 | goto out_duplicate; |
| 394 | |
| 395 | delta -= len + 1; |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 396 | if (++cur_head == buf_end) |
| 397 | cur_head = av->av_buf; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 398 | } |
| 399 | } |
| 400 | |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 401 | av->av_buf_ackno = ackno; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 402 | out: |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 403 | return 0; |
| 404 | |
| 405 | out_duplicate: |
| 406 | /* Duplicate packet */ |
| 407 | dccp_pr_debug("Received a dup or already considered lost " |
| 408 | "packet: %llu\n", (unsigned long long)ackno); |
| 409 | return -EILSEQ; |
| 410 | } |
| 411 | |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 412 | static void dccp_ackvec_throw_record(struct dccp_ackvec *av, |
| 413 | struct dccp_ackvec_record *avr) |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 414 | { |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 415 | struct dccp_ackvec_record *next; |
| 416 | |
Andrea Bittau | 23d06e3 | 2006-09-19 13:04:54 -0700 | [diff] [blame] | 417 | /* sort out vector length */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 418 | if (av->av_buf_head <= avr->avr_ack_ptr) |
| 419 | av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head; |
Andrea Bittau | 23d06e3 | 2006-09-19 13:04:54 -0700 | [diff] [blame] | 420 | else |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 421 | av->av_vec_len = DCCPAV_MAX_ACKVEC_LEN - 1 - |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 422 | av->av_buf_head + avr->avr_ack_ptr; |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 423 | |
| 424 | /* free records */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 425 | list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 426 | list_del(&avr->avr_node); |
| 427 | kmem_cache_free(dccp_ackvec_record_slab, avr); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 428 | } |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 429 | } |
| 430 | |
| 431 | void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, |
| 432 | const u64 ackno) |
| 433 | { |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 434 | struct dccp_ackvec_record *avr; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 435 | |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 436 | /* |
| 437 | * If we traverse backwards, it should be faster when we have large |
| 438 | * windows. We will be receiving ACKs for stuff we sent a while back |
| 439 | * -sorbo. |
| 440 | */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 441 | list_for_each_entry_reverse(avr, &av->av_records, avr_node) { |
| 442 | if (ackno == avr->avr_ack_seqno) { |
Gerrit Renker | 09dbc38 | 2006-11-14 12:57:34 -0200 | [diff] [blame] | 443 | dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, " |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 444 | "ack_ackno=%llu, ACKED!\n", |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 445 | dccp_role(sk), avr->avr_ack_runlen, |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 446 | (unsigned long long)avr->avr_ack_seqno, |
| 447 | (unsigned long long)avr->avr_ack_ackno); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 448 | dccp_ackvec_throw_record(av, avr); |
| 449 | break; |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 450 | } else if (avr->avr_ack_seqno > ackno) |
Andrea Bittau | d23ca15 | 2006-11-14 13:19:45 -0200 | [diff] [blame] | 451 | break; /* old news */ |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 452 | } |
| 453 | } |
| 454 | |
| 455 | static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, |
Andrea Bittau | bdf13d2 | 2006-11-24 13:02:42 -0200 | [diff] [blame] | 456 | struct sock *sk, u64 *ackno, |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 457 | const unsigned char len, |
| 458 | const unsigned char *vector) |
| 459 | { |
| 460 | unsigned char i; |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 461 | struct dccp_ackvec_record *avr; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 462 | |
| 463 | /* Check if we actually sent an ACK vector */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 464 | if (list_empty(&av->av_records)) |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 465 | return; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 466 | |
| 467 | i = len; |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 468 | /* |
| 469 | * XXX |
| 470 | * I think it might be more efficient to work backwards. See comment on |
| 471 | * rcv_ackno. -sorbo. |
| 472 | */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 473 | avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 474 | while (i--) { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 475 | const u8 rl = dccp_ackvec_runlen(vector); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 476 | u64 ackno_end_rl; |
| 477 | |
Andrea Bittau | bdf13d2 | 2006-11-24 13:02:42 -0200 | [diff] [blame] | 478 | dccp_set_seqno(&ackno_end_rl, *ackno - rl); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 479 | |
| 480 | /* |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 481 | * If our AVR sequence number is greater than the ack, go |
| 482 | * forward in the AVR list until it is not so. |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 483 | */ |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 484 | list_for_each_entry_from(avr, &av->av_records, avr_node) { |
| 485 | if (!after48(avr->avr_ack_seqno, *ackno)) |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 486 | goto found; |
| 487 | } |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 488 | /* End of the av_records list, not found, exit */ |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 489 | break; |
| 490 | found: |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 491 | if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) { |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 492 | if (dccp_ackvec_state(vector) != DCCPAV_NOT_RECEIVED) { |
Gerrit Renker | 09dbc38 | 2006-11-14 12:57:34 -0200 | [diff] [blame] | 493 | dccp_pr_debug("%s ACK vector 0, len=%d, " |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 494 | "ack_seqno=%llu, ack_ackno=%llu, " |
| 495 | "ACKED!\n", |
Gerrit Renker | 09dbc38 | 2006-11-14 12:57:34 -0200 | [diff] [blame] | 496 | dccp_role(sk), len, |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 497 | (unsigned long long) |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 498 | avr->avr_ack_seqno, |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 499 | (unsigned long long) |
Gerrit Renker | a47c510 | 2007-12-30 04:19:31 -0800 | [diff] [blame] | 500 | avr->avr_ack_ackno); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 501 | dccp_ackvec_throw_record(av, avr); |
Andrea Bittau | afec35e | 2006-06-11 20:58:33 -0700 | [diff] [blame] | 502 | break; |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 503 | } |
| 504 | /* |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 505 | * If it wasn't received, continue scanning... we might |
| 506 | * find another one. |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 507 | */ |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 508 | } |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 509 | |
Andrea Bittau | bdf13d2 | 2006-11-24 13:02:42 -0200 | [diff] [blame] | 510 | dccp_set_seqno(ackno, ackno_end_rl - 1); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 511 | ++vector; |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, |
Andrea Bittau | bdf13d2 | 2006-11-24 13:02:42 -0200 | [diff] [blame] | 516 | u64 *ackno, const u8 opt, const u8 *value, const u8 len) |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 517 | { |
Gerrit Renker | b20a9c2 | 2008-11-23 16:02:31 -0800 | [diff] [blame] | 518 | if (len > DCCP_SINGLE_OPT_MAXLEN) |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 519 | return -1; |
| 520 | |
| 521 | /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */ |
| 522 | dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk, |
Andrea Bittau | bdf13d2 | 2006-11-24 13:02:42 -0200 | [diff] [blame] | 523 | ackno, len, value); |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 524 | return 0; |
| 525 | } |
Arnaldo Carvalho de Melo | 9b07ef5 | 2006-03-20 17:16:17 -0800 | [diff] [blame] | 526 | |
Gerrit Renker | 5753fdf | 2010-11-14 17:25:11 +0100 | [diff] [blame] | 527 | /** |
| 528 | * dccp_ackvec_clear_state - Perform house-keeping / garbage-collection |
| 529 | * This routine is called when the peer acknowledges the receipt of Ack Vectors |
| 530 | * up to and including @ackno. While based on on section A.3 of RFC 4340, here |
| 531 | * are additional precautions to prevent corrupted buffer state. In particular, |
| 532 | * we use tail_ackno to identify outdated records; it always marks the earliest |
| 533 | * packet of group (2) in 11.4.2. |
| 534 | */ |
| 535 | void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno) |
| 536 | { |
| 537 | struct dccp_ackvec_record *avr, *next; |
| 538 | u8 runlen_now, eff_runlen; |
| 539 | s64 delta; |
| 540 | |
| 541 | avr = dccp_ackvec_lookup(&av->av_records, ackno); |
| 542 | if (avr == NULL) |
| 543 | return; |
| 544 | /* |
| 545 | * Deal with outdated acknowledgments: this arises when e.g. there are |
| 546 | * several old records and the acks from the peer come in slowly. In |
| 547 | * that case we may still have records that pre-date tail_ackno. |
| 548 | */ |
| 549 | delta = dccp_delta_seqno(av->av_tail_ackno, avr->avr_ack_ackno); |
| 550 | if (delta < 0) |
| 551 | goto free_records; |
| 552 | /* |
| 553 | * Deal with overlapping Ack Vectors: don't subtract more than the |
| 554 | * number of packets between tail_ackno and ack_ackno. |
| 555 | */ |
| 556 | eff_runlen = delta < avr->avr_ack_runlen ? delta : avr->avr_ack_runlen; |
| 557 | |
| 558 | runlen_now = dccp_ackvec_runlen(av->av_buf + avr->avr_ack_ptr); |
| 559 | /* |
| 560 | * The run length of Ack Vector cells does not decrease over time. If |
| 561 | * the run length is the same as at the time the Ack Vector was sent, we |
| 562 | * free the ack_ptr cell. That cell can however not be freed if the run |
| 563 | * length has increased: in this case we need to move the tail pointer |
| 564 | * backwards (towards higher indices), to its next-oldest neighbour. |
| 565 | */ |
| 566 | if (runlen_now > eff_runlen) { |
| 567 | |
| 568 | av->av_buf[avr->avr_ack_ptr] -= eff_runlen + 1; |
| 569 | av->av_buf_tail = __ackvec_idx_add(avr->avr_ack_ptr, 1); |
| 570 | |
| 571 | /* This move may not have cleared the overflow flag. */ |
| 572 | if (av->av_overflow) |
| 573 | av->av_overflow = (av->av_buf_head == av->av_buf_tail); |
| 574 | } else { |
| 575 | av->av_buf_tail = avr->avr_ack_ptr; |
| 576 | /* |
| 577 | * We have made sure that avr points to a valid cell within the |
| 578 | * buffer. This cell is either older than head, or equals head |
| 579 | * (empty buffer): in both cases we no longer have any overflow. |
| 580 | */ |
| 581 | av->av_overflow = 0; |
| 582 | } |
| 583 | |
| 584 | /* |
| 585 | * The peer has acknowledged up to and including ack_ackno. Hence the |
| 586 | * first packet in group (2) of 11.4.2 is the successor of ack_ackno. |
| 587 | */ |
| 588 | av->av_tail_ackno = ADD48(avr->avr_ack_ackno, 1); |
| 589 | |
| 590 | free_records: |
| 591 | list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { |
| 592 | list_del(&avr->avr_node); |
| 593 | kmem_cache_free(dccp_ackvec_record_slab, avr); |
| 594 | } |
| 595 | } |
| 596 | |
Arnaldo Carvalho de Melo | 9b07ef5 | 2006-03-20 17:16:17 -0800 | [diff] [blame] | 597 | int __init dccp_ackvec_init(void) |
| 598 | { |
| 599 | dccp_ackvec_slab = kmem_cache_create("dccp_ackvec", |
| 600 | sizeof(struct dccp_ackvec), 0, |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 601 | SLAB_HWCACHE_ALIGN, NULL); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 602 | if (dccp_ackvec_slab == NULL) |
| 603 | goto out_err; |
| 604 | |
Gerrit Renker | f17a37c | 2010-11-10 21:20:07 +0100 | [diff] [blame] | 605 | dccp_ackvec_record_slab = kmem_cache_create("dccp_ackvec_record", |
| 606 | sizeof(struct dccp_ackvec_record), |
| 607 | 0, SLAB_HWCACHE_ALIGN, NULL); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 608 | if (dccp_ackvec_record_slab == NULL) |
| 609 | goto out_destroy_slab; |
Arnaldo Carvalho de Melo | 9b07ef5 | 2006-03-20 17:16:17 -0800 | [diff] [blame] | 610 | |
| 611 | return 0; |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 612 | |
| 613 | out_destroy_slab: |
| 614 | kmem_cache_destroy(dccp_ackvec_slab); |
| 615 | dccp_ackvec_slab = NULL; |
| 616 | out_err: |
Gerrit Renker | 59348b1 | 2006-11-20 18:39:23 -0200 | [diff] [blame] | 617 | DCCP_CRIT("Unable to create Ack Vector slab cache"); |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 618 | return -ENOBUFS; |
Arnaldo Carvalho de Melo | 9b07ef5 | 2006-03-20 17:16:17 -0800 | [diff] [blame] | 619 | } |
| 620 | |
| 621 | void dccp_ackvec_exit(void) |
| 622 | { |
| 623 | if (dccp_ackvec_slab != NULL) { |
| 624 | kmem_cache_destroy(dccp_ackvec_slab); |
| 625 | dccp_ackvec_slab = NULL; |
| 626 | } |
Andrea Bittau | 02bcf28 | 2006-03-20 17:19:55 -0800 | [diff] [blame] | 627 | if (dccp_ackvec_record_slab != NULL) { |
| 628 | kmem_cache_destroy(dccp_ackvec_record_slab); |
| 629 | dccp_ackvec_record_slab = NULL; |
| 630 | } |
Arnaldo Carvalho de Melo | 9b07ef5 | 2006-03-20 17:16:17 -0800 | [diff] [blame] | 631 | } |