Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 1 | /* |
| 2 | * net/dccp/ccids/ccid2.c |
| 3 | * |
| 4 | * Copyright (c) 2005, 2006 Andrea Bittau <a.bittau@cs.ucl.ac.uk> |
| 5 | * |
| 6 | * Changes to meet Linux coding standards, and DCCP infrastructure fixes. |
| 7 | * |
| 8 | * Copyright (c) 2006 Arnaldo Carvalho de Melo <acme@conectiva.com.br> |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to the Free Software |
| 22 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 23 | */ |
| 24 | |
| 25 | /* |
| 26 | * This implementation should follow: draft-ietf-dccp-ccid2-10.txt |
| 27 | * |
| 28 | * BUGS: |
| 29 | * - sequence number wrapping |
| 30 | * - jiffies wrapping |
| 31 | */ |
| 32 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 33 | #include "../ccid.h" |
| 34 | #include "../dccp.h" |
| 35 | #include "ccid2.h" |
| 36 | |
| 37 | static int ccid2_debug; |
| 38 | |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 39 | #undef CCID2_DEBUG |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 40 | #ifdef CCID2_DEBUG |
| 41 | #define ccid2_pr_debug(format, a...) \ |
| 42 | do { if (ccid2_debug) \ |
| 43 | printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \ |
| 44 | } while (0) |
| 45 | #else |
| 46 | #define ccid2_pr_debug(format, a...) |
| 47 | #endif |
| 48 | |
| 49 | static const int ccid2_seq_len = 128; |
| 50 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 51 | #ifdef CCID2_DEBUG |
| 52 | static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx) |
| 53 | { |
| 54 | int len = 0; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 55 | int pipe = 0; |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 56 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqh; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 57 | |
| 58 | /* there is data in the chain */ |
| 59 | if (seqp != hctx->ccid2hctx_seqt) { |
| 60 | seqp = seqp->ccid2s_prev; |
| 61 | len++; |
| 62 | if (!seqp->ccid2s_acked) |
| 63 | pipe++; |
| 64 | |
| 65 | while (seqp != hctx->ccid2hctx_seqt) { |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 66 | struct ccid2_seq *prev = seqp->ccid2s_prev; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 67 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 68 | len++; |
| 69 | if (!prev->ccid2s_acked) |
| 70 | pipe++; |
| 71 | |
| 72 | /* packets are sent sequentially */ |
| 73 | BUG_ON(seqp->ccid2s_seq <= prev->ccid2s_seq); |
| 74 | BUG_ON(seqp->ccid2s_sent < prev->ccid2s_sent); |
| 75 | BUG_ON(len > ccid2_seq_len); |
| 76 | |
| 77 | seqp = prev; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | BUG_ON(pipe != hctx->ccid2hctx_pipe); |
| 82 | ccid2_pr_debug("len of chain=%d\n", len); |
| 83 | |
| 84 | do { |
| 85 | seqp = seqp->ccid2s_prev; |
| 86 | len++; |
| 87 | BUG_ON(len > ccid2_seq_len); |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 88 | } while (seqp != hctx->ccid2hctx_seqh); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 89 | |
| 90 | BUG_ON(len != ccid2_seq_len); |
| 91 | ccid2_pr_debug("total len=%d\n", len); |
| 92 | } |
| 93 | #else |
| 94 | #define ccid2_hc_tx_check_sanity(hctx) do {} while (0) |
| 95 | #endif |
| 96 | |
| 97 | static int ccid2_hc_tx_send_packet(struct sock *sk, |
| 98 | struct sk_buff *skb, int len) |
| 99 | { |
| 100 | struct ccid2_hc_tx_sock *hctx; |
| 101 | |
| 102 | switch (DCCP_SKB_CB(skb)->dccpd_type) { |
| 103 | case 0: /* XXX data packets from userland come through like this */ |
| 104 | case DCCP_PKT_DATA: |
| 105 | case DCCP_PKT_DATAACK: |
| 106 | break; |
| 107 | /* No congestion control on other packets */ |
| 108 | default: |
| 109 | return 0; |
| 110 | } |
| 111 | |
| 112 | hctx = ccid2_hc_tx_sk(sk); |
| 113 | |
| 114 | ccid2_pr_debug("pipe=%d cwnd=%d\n", hctx->ccid2hctx_pipe, |
| 115 | hctx->ccid2hctx_cwnd); |
| 116 | |
| 117 | if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) { |
| 118 | /* OK we can send... make sure previous packet was sent off */ |
| 119 | if (!hctx->ccid2hctx_sendwait) { |
| 120 | hctx->ccid2hctx_sendwait = 1; |
| 121 | return 0; |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | return 100; /* XXX */ |
| 126 | } |
| 127 | |
| 128 | static void ccid2_change_l_ack_ratio(struct sock *sk, int val) |
| 129 | { |
| 130 | struct dccp_sock *dp = dccp_sk(sk); |
| 131 | /* |
| 132 | * XXX I don't really agree with val != 2. If cwnd is 1, ack ratio |
| 133 | * should be 1... it shouldn't be allowed to become 2. |
| 134 | * -sorbo. |
| 135 | */ |
| 136 | if (val != 2) { |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 137 | const struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 138 | int max = hctx->ccid2hctx_cwnd / 2; |
| 139 | |
| 140 | /* round up */ |
| 141 | if (hctx->ccid2hctx_cwnd & 1) |
| 142 | max++; |
| 143 | |
| 144 | if (val > max) |
| 145 | val = max; |
| 146 | } |
| 147 | |
| 148 | ccid2_pr_debug("changing local ack ratio to %d\n", val); |
| 149 | WARN_ON(val <= 0); |
| 150 | dp->dccps_l_ack_ratio = val; |
| 151 | } |
| 152 | |
| 153 | static void ccid2_change_cwnd(struct sock *sk, int val) |
| 154 | { |
| 155 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 156 | |
| 157 | if (val == 0) |
| 158 | val = 1; |
| 159 | |
| 160 | /* XXX do we need to change ack ratio? */ |
| 161 | ccid2_pr_debug("change cwnd to %d\n", val); |
| 162 | |
| 163 | BUG_ON(val < 1); |
| 164 | hctx->ccid2hctx_cwnd = val; |
| 165 | } |
| 166 | |
| 167 | static void ccid2_start_rto_timer(struct sock *sk); |
| 168 | |
| 169 | static void ccid2_hc_tx_rto_expire(unsigned long data) |
| 170 | { |
| 171 | struct sock *sk = (struct sock *)data; |
| 172 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 173 | long s; |
| 174 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 175 | bh_lock_sock(sk); |
| 176 | if (sock_owned_by_user(sk)) { |
| 177 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, |
| 178 | jiffies + HZ / 5); |
| 179 | goto out; |
| 180 | } |
| 181 | |
| 182 | ccid2_pr_debug("RTO_EXPIRE\n"); |
| 183 | |
| 184 | ccid2_hc_tx_check_sanity(hctx); |
| 185 | |
| 186 | /* back-off timer */ |
| 187 | hctx->ccid2hctx_rto <<= 1; |
| 188 | |
| 189 | s = hctx->ccid2hctx_rto / HZ; |
| 190 | if (s > 60) |
| 191 | hctx->ccid2hctx_rto = 60 * HZ; |
| 192 | |
| 193 | ccid2_start_rto_timer(sk); |
| 194 | |
| 195 | /* adjust pipe, cwnd etc */ |
| 196 | hctx->ccid2hctx_pipe = 0; |
| 197 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1; |
| 198 | if (hctx->ccid2hctx_ssthresh < 2) |
| 199 | hctx->ccid2hctx_ssthresh = 2; |
| 200 | ccid2_change_cwnd(sk, 1); |
| 201 | |
| 202 | /* clear state about stuff we sent */ |
| 203 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; |
| 204 | hctx->ccid2hctx_ssacks = 0; |
| 205 | hctx->ccid2hctx_acks = 0; |
| 206 | hctx->ccid2hctx_sent = 0; |
| 207 | |
| 208 | /* clear ack ratio state. */ |
| 209 | hctx->ccid2hctx_arsent = 0; |
| 210 | hctx->ccid2hctx_ackloss = 0; |
| 211 | hctx->ccid2hctx_rpseq = 0; |
| 212 | hctx->ccid2hctx_rpdupack = -1; |
| 213 | ccid2_change_l_ack_ratio(sk, 1); |
| 214 | ccid2_hc_tx_check_sanity(hctx); |
| 215 | out: |
| 216 | bh_unlock_sock(sk); |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 217 | sock_put(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 218 | } |
| 219 | |
| 220 | static void ccid2_start_rto_timer(struct sock *sk) |
| 221 | { |
| 222 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 223 | |
| 224 | ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto); |
| 225 | |
| 226 | BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer)); |
| 227 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, |
| 228 | jiffies + hctx->ccid2hctx_rto); |
| 229 | } |
| 230 | |
| 231 | static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, int len) |
| 232 | { |
| 233 | struct dccp_sock *dp = dccp_sk(sk); |
| 234 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 235 | u64 seq; |
| 236 | |
| 237 | ccid2_hc_tx_check_sanity(hctx); |
| 238 | |
| 239 | BUG_ON(!hctx->ccid2hctx_sendwait); |
| 240 | hctx->ccid2hctx_sendwait = 0; |
| 241 | hctx->ccid2hctx_pipe++; |
| 242 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
| 243 | |
| 244 | /* There is an issue. What if another packet is sent between |
| 245 | * packet_send() and packet_sent(). Then the sequence number would be |
| 246 | * wrong. |
| 247 | * -sorbo. |
| 248 | */ |
| 249 | seq = dp->dccps_gss; |
| 250 | |
| 251 | hctx->ccid2hctx_seqh->ccid2s_seq = seq; |
| 252 | hctx->ccid2hctx_seqh->ccid2s_acked = 0; |
| 253 | hctx->ccid2hctx_seqh->ccid2s_sent = jiffies; |
| 254 | hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqh->ccid2s_next; |
| 255 | |
| 256 | ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd, |
| 257 | hctx->ccid2hctx_pipe); |
| 258 | |
| 259 | if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) { |
| 260 | /* XXX allocate more space */ |
| 261 | WARN_ON(1); |
| 262 | } |
| 263 | |
| 264 | hctx->ccid2hctx_sent++; |
| 265 | |
| 266 | /* Ack Ratio. Need to maintain a concept of how many windows we sent */ |
| 267 | hctx->ccid2hctx_arsent++; |
| 268 | /* We had an ack loss in this window... */ |
| 269 | if (hctx->ccid2hctx_ackloss) { |
| 270 | if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) { |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 271 | hctx->ccid2hctx_arsent = 0; |
| 272 | hctx->ccid2hctx_ackloss = 0; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 273 | } |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 274 | } else { |
| 275 | /* No acks lost up to now... */ |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 276 | /* decrease ack ratio if enough packets were sent */ |
| 277 | if (dp->dccps_l_ack_ratio > 1) { |
| 278 | /* XXX don't calculate denominator each time */ |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 279 | int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - |
| 280 | dp->dccps_l_ack_ratio; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 281 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 282 | denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom; |
| 283 | |
| 284 | if (hctx->ccid2hctx_arsent >= denom) { |
| 285 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); |
| 286 | hctx->ccid2hctx_arsent = 0; |
| 287 | } |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 288 | } else { |
| 289 | /* we can't increase ack ratio further [1] */ |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 290 | hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | /* setup RTO timer */ |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 295 | if (!timer_pending(&hctx->ccid2hctx_rtotimer)) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 296 | ccid2_start_rto_timer(sk); |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 297 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 298 | #ifdef CCID2_DEBUG |
| 299 | ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe); |
| 300 | ccid2_pr_debug("Sent: seq=%llu\n", seq); |
| 301 | do { |
| 302 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqt; |
| 303 | |
| 304 | while (seqp != hctx->ccid2hctx_seqh) { |
| 305 | ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n", |
| 306 | seqp->ccid2s_seq, seqp->ccid2s_acked, |
| 307 | seqp->ccid2s_sent); |
| 308 | seqp = seqp->ccid2s_next; |
| 309 | } |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 310 | } while (0); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 311 | ccid2_pr_debug("=========\n"); |
| 312 | ccid2_hc_tx_check_sanity(hctx); |
| 313 | #endif |
| 314 | } |
| 315 | |
| 316 | /* XXX Lame code duplication! |
| 317 | * returns -1 if none was found. |
| 318 | * else returns the next offset to use in the function call. |
| 319 | */ |
| 320 | static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, |
| 321 | unsigned char **vec, unsigned char *veclen) |
| 322 | { |
| 323 | const struct dccp_hdr *dh = dccp_hdr(skb); |
| 324 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); |
| 325 | unsigned char *opt_ptr; |
| 326 | const unsigned char *opt_end = (unsigned char *)dh + |
| 327 | (dh->dccph_doff * 4); |
| 328 | unsigned char opt, len; |
| 329 | unsigned char *value; |
| 330 | |
| 331 | BUG_ON(offset < 0); |
| 332 | options += offset; |
| 333 | opt_ptr = options; |
| 334 | if (opt_ptr >= opt_end) |
| 335 | return -1; |
| 336 | |
| 337 | while (opt_ptr != opt_end) { |
| 338 | opt = *opt_ptr++; |
| 339 | len = 0; |
| 340 | value = NULL; |
| 341 | |
| 342 | /* Check if this isn't a single byte option */ |
| 343 | if (opt > DCCPO_MAX_RESERVED) { |
| 344 | if (opt_ptr == opt_end) |
| 345 | goto out_invalid_option; |
| 346 | |
| 347 | len = *opt_ptr++; |
| 348 | if (len < 3) |
| 349 | goto out_invalid_option; |
| 350 | /* |
| 351 | * Remove the type and len fields, leaving |
| 352 | * just the value size |
| 353 | */ |
| 354 | len -= 2; |
| 355 | value = opt_ptr; |
| 356 | opt_ptr += len; |
| 357 | |
| 358 | if (opt_ptr > opt_end) |
| 359 | goto out_invalid_option; |
| 360 | } |
| 361 | |
| 362 | switch (opt) { |
| 363 | case DCCPO_ACK_VECTOR_0: |
| 364 | case DCCPO_ACK_VECTOR_1: |
| 365 | *vec = value; |
| 366 | *veclen = len; |
| 367 | return offset + (opt_ptr - options); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 368 | } |
| 369 | } |
| 370 | |
| 371 | return -1; |
| 372 | |
| 373 | out_invalid_option: |
| 374 | BUG_ON(1); /* should never happen... options were previously parsed ! */ |
| 375 | return -1; |
| 376 | } |
| 377 | |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 378 | static void ccid2_hc_tx_kill_rto_timer(struct sock *sk) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 379 | { |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 380 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 381 | |
| 382 | sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer); |
| 383 | ccid2_pr_debug("deleted RTO timer\n"); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 384 | } |
| 385 | |
| 386 | static inline void ccid2_new_ack(struct sock *sk, |
| 387 | struct ccid2_seq *seqp, |
| 388 | unsigned int *maxincr) |
| 389 | { |
| 390 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 391 | |
| 392 | /* slow start */ |
| 393 | if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { |
| 394 | hctx->ccid2hctx_acks = 0; |
| 395 | |
| 396 | /* We can increase cwnd at most maxincr [ack_ratio/2] */ |
| 397 | if (*maxincr) { |
| 398 | /* increase every 2 acks */ |
| 399 | hctx->ccid2hctx_ssacks++; |
| 400 | if (hctx->ccid2hctx_ssacks == 2) { |
| 401 | ccid2_change_cwnd(sk, hctx->ccid2hctx_cwnd + 1); |
| 402 | hctx->ccid2hctx_ssacks = 0; |
| 403 | *maxincr = *maxincr - 1; |
| 404 | } |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 405 | } else { |
| 406 | /* increased cwnd enough for this single ack */ |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 407 | hctx->ccid2hctx_ssacks = 0; |
| 408 | } |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 409 | } else { |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 410 | hctx->ccid2hctx_ssacks = 0; |
| 411 | hctx->ccid2hctx_acks++; |
| 412 | |
| 413 | if (hctx->ccid2hctx_acks >= hctx->ccid2hctx_cwnd) { |
| 414 | ccid2_change_cwnd(sk, hctx->ccid2hctx_cwnd + 1); |
| 415 | hctx->ccid2hctx_acks = 0; |
| 416 | } |
| 417 | } |
| 418 | |
| 419 | /* update RTO */ |
| 420 | if (hctx->ccid2hctx_srtt == -1 || |
| 421 | (jiffies - hctx->ccid2hctx_lastrtt) >= hctx->ccid2hctx_srtt) { |
| 422 | unsigned long r = jiffies - seqp->ccid2s_sent; |
| 423 | int s; |
| 424 | |
| 425 | /* first measurement */ |
| 426 | if (hctx->ccid2hctx_srtt == -1) { |
| 427 | ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n", |
| 428 | r, jiffies, seqp->ccid2s_seq); |
| 429 | hctx->ccid2hctx_srtt = r; |
| 430 | hctx->ccid2hctx_rttvar = r >> 1; |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 431 | } else { |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 432 | /* RTTVAR */ |
| 433 | long tmp = hctx->ccid2hctx_srtt - r; |
| 434 | if (tmp < 0) |
| 435 | tmp *= -1; |
| 436 | |
| 437 | tmp >>= 2; |
| 438 | hctx->ccid2hctx_rttvar *= 3; |
| 439 | hctx->ccid2hctx_rttvar >>= 2; |
| 440 | hctx->ccid2hctx_rttvar += tmp; |
| 441 | |
| 442 | /* SRTT */ |
| 443 | hctx->ccid2hctx_srtt *= 7; |
| 444 | hctx->ccid2hctx_srtt >>= 3; |
| 445 | tmp = r >> 3; |
| 446 | hctx->ccid2hctx_srtt += tmp; |
| 447 | } |
| 448 | s = hctx->ccid2hctx_rttvar << 2; |
| 449 | /* clock granularity is 1 when based on jiffies */ |
| 450 | if (!s) |
| 451 | s = 1; |
| 452 | hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s; |
| 453 | |
| 454 | /* must be at least a second */ |
| 455 | s = hctx->ccid2hctx_rto / HZ; |
| 456 | /* DCCP doesn't require this [but I like it cuz my code sux] */ |
| 457 | #if 1 |
| 458 | if (s < 1) |
| 459 | hctx->ccid2hctx_rto = HZ; |
| 460 | #endif |
| 461 | /* max 60 seconds */ |
| 462 | if (s > 60) |
| 463 | hctx->ccid2hctx_rto = HZ * 60; |
| 464 | |
| 465 | hctx->ccid2hctx_lastrtt = jiffies; |
| 466 | |
| 467 | ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n", |
| 468 | hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar, |
| 469 | hctx->ccid2hctx_rto, HZ, r); |
| 470 | hctx->ccid2hctx_sent = 0; |
| 471 | } |
| 472 | |
| 473 | /* we got a new ack, so re-start RTO timer */ |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 474 | ccid2_hc_tx_kill_rto_timer(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 475 | ccid2_start_rto_timer(sk); |
| 476 | } |
| 477 | |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 478 | static void ccid2_hc_tx_dec_pipe(struct sock *sk) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 479 | { |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 480 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 481 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 482 | hctx->ccid2hctx_pipe--; |
| 483 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
| 484 | |
| 485 | if (hctx->ccid2hctx_pipe == 0) |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 486 | ccid2_hc_tx_kill_rto_timer(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 487 | } |
| 488 | |
| 489 | static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) |
| 490 | { |
| 491 | struct dccp_sock *dp = dccp_sk(sk); |
| 492 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| 493 | u64 ackno, seqno; |
| 494 | struct ccid2_seq *seqp; |
| 495 | unsigned char *vector; |
| 496 | unsigned char veclen; |
| 497 | int offset = 0; |
| 498 | int done = 0; |
| 499 | int loss = 0; |
| 500 | unsigned int maxincr = 0; |
| 501 | |
| 502 | ccid2_hc_tx_check_sanity(hctx); |
| 503 | /* check reverse path congestion */ |
| 504 | seqno = DCCP_SKB_CB(skb)->dccpd_seq; |
| 505 | |
| 506 | /* XXX this whole "algorithm" is broken. Need to fix it to keep track |
| 507 | * of the seqnos of the dupacks so that rpseq and rpdupack are correct |
| 508 | * -sorbo. |
| 509 | */ |
| 510 | /* need to bootstrap */ |
| 511 | if (hctx->ccid2hctx_rpdupack == -1) { |
| 512 | hctx->ccid2hctx_rpdupack = 0; |
| 513 | hctx->ccid2hctx_rpseq = seqno; |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 514 | } else { |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 515 | /* check if packet is consecutive */ |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 516 | if ((hctx->ccid2hctx_rpseq + 1) == seqno) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 517 | hctx->ccid2hctx_rpseq++; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 518 | /* it's a later packet */ |
| 519 | else if (after48(seqno, hctx->ccid2hctx_rpseq)) { |
| 520 | hctx->ccid2hctx_rpdupack++; |
| 521 | |
| 522 | /* check if we got enough dupacks */ |
| 523 | if (hctx->ccid2hctx_rpdupack >= |
| 524 | hctx->ccid2hctx_numdupack) { |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 525 | hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ |
| 526 | hctx->ccid2hctx_rpseq = 0; |
| 527 | |
| 528 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio << 1); |
| 529 | } |
| 530 | } |
| 531 | } |
| 532 | |
| 533 | /* check forward path congestion */ |
| 534 | /* still didn't send out new data packets */ |
| 535 | if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) |
| 536 | return; |
| 537 | |
| 538 | switch (DCCP_SKB_CB(skb)->dccpd_type) { |
| 539 | case DCCP_PKT_ACK: |
| 540 | case DCCP_PKT_DATAACK: |
| 541 | break; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 542 | default: |
| 543 | return; |
| 544 | } |
| 545 | |
| 546 | ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; |
| 547 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; |
| 548 | |
| 549 | /* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for |
| 550 | * this single ack. I round up. |
| 551 | * -sorbo. |
| 552 | */ |
| 553 | maxincr = dp->dccps_l_ack_ratio >> 1; |
| 554 | maxincr++; |
| 555 | |
| 556 | /* go through all ack vectors */ |
| 557 | while ((offset = ccid2_ackvector(sk, skb, offset, |
| 558 | &vector, &veclen)) != -1) { |
| 559 | /* go through this ack vector */ |
| 560 | while (veclen--) { |
| 561 | const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; |
| 562 | u64 ackno_end_rl; |
| 563 | |
| 564 | dccp_set_seqno(&ackno_end_rl, ackno - rl); |
| 565 | ccid2_pr_debug("ackvec start:%llu end:%llu\n", ackno, |
| 566 | ackno_end_rl); |
| 567 | /* if the seqno we are analyzing is larger than the |
| 568 | * current ackno, then move towards the tail of our |
| 569 | * seqnos. |
| 570 | */ |
| 571 | while (after48(seqp->ccid2s_seq, ackno)) { |
| 572 | if (seqp == hctx->ccid2hctx_seqt) { |
| 573 | done = 1; |
| 574 | break; |
| 575 | } |
| 576 | seqp = seqp->ccid2s_prev; |
| 577 | } |
| 578 | if (done) |
| 579 | break; |
| 580 | |
| 581 | /* check all seqnos in the range of the vector |
| 582 | * run length |
| 583 | */ |
| 584 | while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { |
Andrea Bittau | 8e27e46 | 2006-09-19 13:05:35 -0700 | [diff] [blame] | 585 | const u8 state = *vector & |
| 586 | DCCP_ACKVEC_STATE_MASK; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 587 | |
| 588 | /* new packet received or marked */ |
| 589 | if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED && |
| 590 | !seqp->ccid2s_acked) { |
| 591 | if (state == |
| 592 | DCCP_ACKVEC_STATE_ECN_MARKED) { |
| 593 | loss = 1; |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 594 | } else |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 595 | ccid2_new_ack(sk, seqp, |
| 596 | &maxincr); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 597 | |
| 598 | seqp->ccid2s_acked = 1; |
| 599 | ccid2_pr_debug("Got ack for %llu\n", |
| 600 | seqp->ccid2s_seq); |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 601 | ccid2_hc_tx_dec_pipe(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 602 | } |
| 603 | if (seqp == hctx->ccid2hctx_seqt) { |
| 604 | done = 1; |
| 605 | break; |
| 606 | } |
| 607 | seqp = seqp->ccid2s_next; |
| 608 | } |
| 609 | if (done) |
| 610 | break; |
| 611 | |
| 612 | |
| 613 | dccp_set_seqno(&ackno, ackno_end_rl - 1); |
| 614 | vector++; |
| 615 | } |
| 616 | if (done) |
| 617 | break; |
| 618 | } |
| 619 | |
| 620 | /* The state about what is acked should be correct now |
| 621 | * Check for NUMDUPACK |
| 622 | */ |
| 623 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; |
| 624 | done = 0; |
| 625 | while (1) { |
| 626 | if (seqp->ccid2s_acked) { |
| 627 | done++; |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 628 | if (done == hctx->ccid2hctx_numdupack) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 629 | break; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 630 | } |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 631 | if (seqp == hctx->ccid2hctx_seqt) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 632 | break; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 633 | seqp = seqp->ccid2s_prev; |
| 634 | } |
| 635 | |
| 636 | /* If there are at least 3 acknowledgements, anything unacknowledged |
| 637 | * below the last sequence number is considered lost |
| 638 | */ |
| 639 | if (done == hctx->ccid2hctx_numdupack) { |
| 640 | struct ccid2_seq *last_acked = seqp; |
| 641 | |
| 642 | /* check for lost packets */ |
| 643 | while (1) { |
| 644 | if (!seqp->ccid2s_acked) { |
| 645 | loss = 1; |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 646 | ccid2_hc_tx_dec_pipe(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 647 | } |
| 648 | if (seqp == hctx->ccid2hctx_seqt) |
| 649 | break; |
| 650 | seqp = seqp->ccid2s_prev; |
| 651 | } |
| 652 | |
| 653 | hctx->ccid2hctx_seqt = last_acked; |
| 654 | } |
| 655 | |
| 656 | /* trim acked packets in tail */ |
| 657 | while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) { |
| 658 | if (!hctx->ccid2hctx_seqt->ccid2s_acked) |
| 659 | break; |
| 660 | |
| 661 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next; |
| 662 | } |
| 663 | |
| 664 | if (loss) { |
| 665 | /* XXX do bit shifts guarantee a 0 as the new bit? */ |
| 666 | ccid2_change_cwnd(sk, hctx->ccid2hctx_cwnd >> 1); |
| 667 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd; |
| 668 | if (hctx->ccid2hctx_ssthresh < 2) |
| 669 | hctx->ccid2hctx_ssthresh = 2; |
| 670 | } |
| 671 | |
| 672 | ccid2_hc_tx_check_sanity(hctx); |
| 673 | } |
| 674 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 675 | static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 676 | { |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 677 | struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 678 | int seqcount = ccid2_seq_len; |
| 679 | int i; |
| 680 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 681 | /* XXX init variables with proper values */ |
| 682 | hctx->ccid2hctx_cwnd = 1; |
| 683 | hctx->ccid2hctx_ssthresh = 10; |
| 684 | hctx->ccid2hctx_numdupack = 3; |
| 685 | |
| 686 | /* XXX init ~ to window size... */ |
| 687 | hctx->ccid2hctx_seqbuf = kmalloc(sizeof(*hctx->ccid2hctx_seqbuf) * |
| 688 | seqcount, gfp_any()); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 689 | if (hctx->ccid2hctx_seqbuf == NULL) |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 690 | return -ENOMEM; |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 691 | |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 692 | for (i = 0; i < (seqcount - 1); i++) { |
| 693 | hctx->ccid2hctx_seqbuf[i].ccid2s_next = |
| 694 | &hctx->ccid2hctx_seqbuf[i + 1]; |
| 695 | hctx->ccid2hctx_seqbuf[i + 1].ccid2s_prev = |
| 696 | &hctx->ccid2hctx_seqbuf[i]; |
| 697 | } |
| 698 | hctx->ccid2hctx_seqbuf[seqcount - 1].ccid2s_next = |
| 699 | hctx->ccid2hctx_seqbuf; |
| 700 | hctx->ccid2hctx_seqbuf->ccid2s_prev = |
| 701 | &hctx->ccid2hctx_seqbuf[seqcount - 1]; |
| 702 | |
| 703 | hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqbuf; |
| 704 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; |
| 705 | hctx->ccid2hctx_sent = 0; |
| 706 | hctx->ccid2hctx_rto = 3 * HZ; |
| 707 | hctx->ccid2hctx_srtt = -1; |
| 708 | hctx->ccid2hctx_rttvar = -1; |
| 709 | hctx->ccid2hctx_lastrtt = 0; |
| 710 | hctx->ccid2hctx_rpdupack = -1; |
| 711 | |
| 712 | hctx->ccid2hctx_rtotimer.function = &ccid2_hc_tx_rto_expire; |
| 713 | hctx->ccid2hctx_rtotimer.data = (unsigned long)sk; |
| 714 | init_timer(&hctx->ccid2hctx_rtotimer); |
| 715 | |
| 716 | ccid2_hc_tx_check_sanity(hctx); |
| 717 | return 0; |
| 718 | } |
| 719 | |
| 720 | static void ccid2_hc_tx_exit(struct sock *sk) |
| 721 | { |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 722 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 723 | |
Andrea Bittau | 77ff72d | 2006-03-20 17:57:52 -0800 | [diff] [blame] | 724 | ccid2_hc_tx_kill_rto_timer(sk); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 725 | kfree(hctx->ccid2hctx_seqbuf); |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 726 | hctx->ccid2hctx_seqbuf = NULL; |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 727 | } |
| 728 | |
| 729 | static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) |
| 730 | { |
| 731 | const struct dccp_sock *dp = dccp_sk(sk); |
| 732 | struct ccid2_hc_rx_sock *hcrx = ccid2_hc_rx_sk(sk); |
| 733 | |
| 734 | switch (DCCP_SKB_CB(skb)->dccpd_type) { |
| 735 | case DCCP_PKT_DATA: |
| 736 | case DCCP_PKT_DATAACK: |
| 737 | hcrx->ccid2hcrx_data++; |
| 738 | if (hcrx->ccid2hcrx_data >= dp->dccps_r_ack_ratio) { |
| 739 | dccp_send_ack(sk); |
| 740 | hcrx->ccid2hcrx_data = 0; |
| 741 | } |
| 742 | break; |
| 743 | } |
| 744 | } |
| 745 | |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 746 | static struct ccid_operations ccid2 = { |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 747 | .ccid_id = 2, |
| 748 | .ccid_name = "ccid2", |
| 749 | .ccid_owner = THIS_MODULE, |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 750 | .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 751 | .ccid_hc_tx_init = ccid2_hc_tx_init, |
| 752 | .ccid_hc_tx_exit = ccid2_hc_tx_exit, |
| 753 | .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, |
| 754 | .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, |
| 755 | .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, |
Arnaldo Carvalho de Melo | 91f0ebf | 2006-03-20 19:21:44 -0800 | [diff] [blame] | 756 | .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 757 | .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, |
| 758 | }; |
| 759 | |
| 760 | module_param(ccid2_debug, int, 0444); |
| 761 | MODULE_PARM_DESC(ccid2_debug, "Enable debug messages"); |
| 762 | |
| 763 | static __init int ccid2_module_init(void) |
| 764 | { |
| 765 | return ccid_register(&ccid2); |
| 766 | } |
| 767 | module_init(ccid2_module_init); |
| 768 | |
| 769 | static __exit void ccid2_module_exit(void) |
| 770 | { |
| 771 | ccid_unregister(&ccid2); |
| 772 | } |
| 773 | module_exit(ccid2_module_exit); |
| 774 | |
| 775 | MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>"); |
Arnaldo Carvalho de Melo | c0c736d | 2006-03-20 22:05:37 -0800 | [diff] [blame] | 776 | MODULE_DESCRIPTION("DCCP TCP-Like (CCID2) CCID"); |
Andrea Bittau | 2a91aa3 | 2006-03-20 17:41:47 -0800 | [diff] [blame] | 777 | MODULE_LICENSE("GPL"); |
| 778 | MODULE_ALIAS("net-dccp-ccid-2"); |