1 /* 2 * net/dccp/ccids/ccid3.c 3 * 4 * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. 5 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz> 6 * 7 * An implementation of the DCCP protocol 8 * 9 * This code has been developed by the University of Waikato WAND 10 * research group. For further information please see http://www.wand.net.nz/ 11 * 12 * This code also uses code from Lulea University, rereleased as GPL by its 13 * authors: 14 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon 15 * 16 * Changes to meet Linux coding standards, to make it meet latest ccid3 draft 17 * and to make it work as a loadable module in the DCCP stack written by 18 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. 19 * 20 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> 21 * 22 * This program is free software; you can redistribute it and/or modify 23 * it under the terms of the GNU General Public License as published by 24 * the Free Software Foundation; either version 2 of the License, or 25 * (at your option) any later version. 26 * 27 * This program is distributed in the hope that it will be useful, 28 * but WITHOUT ANY WARRANTY; without even the implied warranty of 29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 30 * GNU General Public License for more details. 31 * 32 * You should have received a copy of the GNU General Public License 33 * along with this program; if not, write to the Free Software 34 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 35 */ 36 #include "../ccid.h" 37 #include "../dccp.h" 38 #include "lib/packet_history.h" 39 #include "lib/loss_interval.h" 40 #include "lib/tfrc.h" 41 #include "ccid3.h" 42 43 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG 44 static int ccid3_debug; 45 #define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) 46 #else 47 #define ccid3_pr_debug(format, a...) 48 #endif 49 50 static struct dccp_tx_hist *ccid3_tx_hist; 51 static struct dccp_rx_hist *ccid3_rx_hist; 52 static struct dccp_li_hist *ccid3_li_hist; 53 54 /* 55 * Transmitter Half-Connection Routines 56 */ 57 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG 58 static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) 59 { 60 static char *ccid3_state_names[] = { 61 [TFRC_SSTATE_NO_SENT] = "NO_SENT", 62 [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", 63 [TFRC_SSTATE_FBACK] = "FBACK", 64 [TFRC_SSTATE_TERM] = "TERM", 65 }; 66 67 return ccid3_state_names[state]; 68 } 69 #endif 70 71 static void ccid3_hc_tx_set_state(struct sock *sk, 72 enum ccid3_hc_tx_states state) 73 { 74 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 75 enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state; 76 77 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", 78 dccp_role(sk), sk, ccid3_tx_state_name(oldstate), 79 ccid3_tx_state_name(state)); 80 WARN_ON(state == oldstate); 81 hctx->ccid3hctx_state = state; 82 } 83 84 /* 85 * Compute the initial sending rate X_init according to RFC 3390: 86 * w_init = min(4 * MSS, max(2 * MSS, 4380 bytes)) 87 * X_init = w_init / RTT 88 * For consistency with other parts of the code, X_init is scaled by 2^6. 89 */ 90 static inline u64 rfc3390_initial_rate(struct sock *sk) 91 { 92 const struct dccp_sock *dp = dccp_sk(sk); 93 const __u32 w_init = min(4 * dp->dccps_mss_cache, 94 max(2 * dp->dccps_mss_cache, 4380U)); 95 96 return scaled_div(w_init << 6, ccid3_hc_tx_sk(sk)->ccid3hctx_rtt); 97 } 98 99 /* 100 * Recalculate t_ipi and delta (should be called whenever X changes) 101 */ 102 static inline void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx) 103 { 104 /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ 105 hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6, 106 hctx->ccid3hctx_x); 107 108 /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ 109 hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, 110 TFRC_OPSYS_HALF_TIME_GRAN); 111 112 ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", 113 hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta, 114 hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6)); 115 116 } 117 /* 118 * Update X by 119 * If (p > 0) 120 * X_calc = calcX(s, R, p); 121 * X = max(min(X_calc, 2 * X_recv), s / t_mbi); 122 * Else 123 * If (now - tld >= R) 124 * X = max(min(2 * X, 2 * X_recv), s / R); 125 * tld = now; 126 * 127 * Note: X and X_recv are both stored in units of 64 * bytes/second, to support 128 * fine-grained resolution of sending rates. This requires scaling by 2^6 129 * throughout the code. Only X_calc is unscaled (in bytes/second). 130 * 131 */ 132 static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now) 133 134 { 135 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 136 __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; 137 const __u64 old_x = hctx->ccid3hctx_x; 138 139 /* 140 * Handle IDLE periods: do not reduce below RFC3390 initial sending rate 141 * when idling [RFC 4342, 5.1]. See also draft-ietf-dccp-rfc3448bis. 142 * For consistency with X and X_recv, min_rate is also scaled by 2^6. 143 */ 144 if (unlikely(hctx->ccid3hctx_idle)) { 145 min_rate = rfc3390_initial_rate(sk); 146 min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); 147 } 148 149 if (hctx->ccid3hctx_p > 0) { 150 151 hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, 152 min_rate); 153 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, 154 (((__u64)hctx->ccid3hctx_s) << 6) / 155 TFRC_T_MBI); 156 157 } else if (timeval_delta(now, &hctx->ccid3hctx_t_ld) - 158 (suseconds_t)hctx->ccid3hctx_rtt >= 0) { 159 160 hctx->ccid3hctx_x = 161 max(min(2 * hctx->ccid3hctx_x, min_rate), 162 scaled_div(((__u64)hctx->ccid3hctx_s) << 6, 163 hctx->ccid3hctx_rtt)); 164 hctx->ccid3hctx_t_ld = *now; 165 } 166 167 if (hctx->ccid3hctx_x != old_x) { 168 ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " 169 "X_recv=%u\n", (unsigned)(old_x >> 6), 170 (unsigned)(hctx->ccid3hctx_x >> 6), 171 hctx->ccid3hctx_x_calc, 172 (unsigned)(hctx->ccid3hctx_x_recv >> 6)); 173 174 ccid3_update_send_interval(hctx); 175 } 176 } 177 178 /* 179 * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) 180 * @len: DCCP packet payload size in bytes 181 */ 182 static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) 183 { 184 const u16 old_s = hctx->ccid3hctx_s; 185 186 hctx->ccid3hctx_s = old_s == 0 ? len : (9 * old_s + len) / 10; 187 188 if (hctx->ccid3hctx_s != old_s) 189 ccid3_update_send_interval(hctx); 190 } 191 192 /* 193 * Update Window Counter using the algorithm from [RFC 4342, 8.1]. 194 * The algorithm is not applicable if RTT < 4 microseconds. 195 */ 196 static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx, 197 struct timeval *now) 198 { 199 suseconds_t delta; 200 u32 quarter_rtts; 201 202 if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */ 203 return; 204 205 delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count); 206 DCCP_BUG_ON(delta < 0); 207 208 quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4); 209 210 if (quarter_rtts > 0) { 211 hctx->ccid3hctx_t_last_win_count = *now; 212 hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5); 213 hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */ 214 215 ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count); 216 } 217 } 218 219 static void ccid3_hc_tx_no_feedback_timer(unsigned long data) 220 { 221 struct sock *sk = (struct sock *)data; 222 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 223 struct timeval now; 224 unsigned long t_nfb = USEC_PER_SEC / 5; 225 226 bh_lock_sock(sk); 227 if (sock_owned_by_user(sk)) { 228 /* Try again later. */ 229 /* XXX: set some sensible MIB */ 230 goto restart_timer; 231 } 232 233 ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, 234 ccid3_tx_state_name(hctx->ccid3hctx_state)); 235 236 hctx->ccid3hctx_idle = 1; 237 238 switch (hctx->ccid3hctx_state) { 239 case TFRC_SSTATE_NO_FBACK: 240 /* RFC 3448, 4.4: Halve send rate directly */ 241 hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2, 242 (((__u64)hctx->ccid3hctx_s) << 6) / 243 TFRC_T_MBI); 244 245 ccid3_pr_debug("%s(%p, state=%s), updated tx rate to %u " 246 "bytes/s\n", dccp_role(sk), sk, 247 ccid3_tx_state_name(hctx->ccid3hctx_state), 248 (unsigned)(hctx->ccid3hctx_x >> 6)); 249 /* The value of R is still undefined and so we can not recompute 250 * the timout value. Keep initial value as per [RFC 4342, 5]. */ 251 t_nfb = TFRC_INITIAL_TIMEOUT; 252 ccid3_update_send_interval(hctx); 253 break; 254 case TFRC_SSTATE_FBACK: 255 /* 256 * Modify the cached value of X_recv [RFC 3448, 4.4] 257 * 258 * If (p == 0 || X_calc > 2 * X_recv) 259 * X_recv = max(X_recv / 2, s / (2 * t_mbi)); 260 * Else 261 * X_recv = X_calc / 4; 262 * 263 * Note that X_recv is scaled by 2^6 while X_calc is not 264 */ 265 BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); 266 267 if (hctx->ccid3hctx_p == 0 || 268 (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5))) { 269 270 hctx->ccid3hctx_x_recv = 271 max(hctx->ccid3hctx_x_recv / 2, 272 (((__u64)hctx->ccid3hctx_s) << 6) / 273 (2 * TFRC_T_MBI)); 274 275 if (hctx->ccid3hctx_p == 0) 276 dccp_timestamp(sk, &now); 277 } else { 278 hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; 279 hctx->ccid3hctx_x_recv <<= 4; 280 } 281 /* Now recalculate X [RFC 3448, 4.3, step (4)] */ 282 ccid3_hc_tx_update_x(sk, &now); 283 /* 284 * Schedule no feedback timer to expire in 285 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) 286 * See comments in packet_recv() regarding the value of t_RTO. 287 */ 288 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); 289 break; 290 case TFRC_SSTATE_NO_SENT: 291 DCCP_BUG("%s(%p) - Illegal state NO_SENT", dccp_role(sk), sk); 292 /* fall through */ 293 case TFRC_SSTATE_TERM: 294 goto out; 295 } 296 297 restart_timer: 298 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, 299 jiffies + usecs_to_jiffies(t_nfb)); 300 out: 301 bh_unlock_sock(sk); 302 sock_put(sk); 303 } 304 305 /* 306 * returns 307 * > 0: delay (in msecs) that should pass before actually sending 308 * = 0: can send immediately 309 * < 0: error condition; do not send packet 310 */ 311 static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) 312 { 313 struct dccp_sock *dp = dccp_sk(sk); 314 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 315 struct timeval now; 316 suseconds_t delay; 317 318 BUG_ON(hctx == NULL); 319 320 /* 321 * This function is called only for Data and DataAck packets. Sending 322 * zero-sized Data(Ack)s is theoretically possible, but for congestion 323 * control this case is pathological - ignore it. 324 */ 325 if (unlikely(skb->len == 0)) 326 return -EBADMSG; 327 328 dccp_timestamp(sk, &now); 329 330 switch (hctx->ccid3hctx_state) { 331 case TFRC_SSTATE_NO_SENT: 332 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, 333 (jiffies + 334 usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); 335 hctx->ccid3hctx_last_win_count = 0; 336 hctx->ccid3hctx_t_last_win_count = now; 337 338 /* Set t_0 for initial packet */ 339 hctx->ccid3hctx_t_nom = now; 340 341 hctx->ccid3hctx_s = skb->len; 342 343 /* 344 * Use initial RTT sample when available: recommended by erratum 345 * to RFC 4342. This implements the initialisation procedure of 346 * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. 347 */ 348 if (dp->dccps_syn_rtt) { 349 ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); 350 hctx->ccid3hctx_rtt = dp->dccps_syn_rtt; 351 hctx->ccid3hctx_x = rfc3390_initial_rate(sk); 352 hctx->ccid3hctx_t_ld = now; 353 } else { 354 /* Sender does not have RTT sample: X = MSS/second */ 355 hctx->ccid3hctx_x = dp->dccps_mss_cache; 356 hctx->ccid3hctx_x <<= 6; 357 } 358 ccid3_update_send_interval(hctx); 359 360 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); 361 break; 362 case TFRC_SSTATE_NO_FBACK: 363 case TFRC_SSTATE_FBACK: 364 delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now); 365 ccid3_pr_debug("delay=%ld\n", (long)delay); 366 /* 367 * Scheduling of packet transmissions [RFC 3448, 4.6] 368 * 369 * if (t_now > t_nom - delta) 370 * // send the packet now 371 * else 372 * // send the packet in (t_nom - t_now) milliseconds. 373 */ 374 if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0) 375 return delay / 1000L; 376 377 ccid3_hc_tx_update_win_count(hctx, &now); 378 break; 379 case TFRC_SSTATE_TERM: 380 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); 381 return -EINVAL; 382 } 383 384 /* prepare to send now (add options etc.) */ 385 dp->dccps_hc_tx_insert_options = 1; 386 DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; 387 hctx->ccid3hctx_idle = 0; 388 389 /* set the nominal send time for the next following packet */ 390 timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi); 391 392 return 0; 393 } 394 395 static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, 396 unsigned int len) 397 { 398 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 399 struct timeval now; 400 struct dccp_tx_hist_entry *packet; 401 402 BUG_ON(hctx == NULL); 403 404 ccid3_hc_tx_update_s(hctx, len); 405 406 packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC); 407 if (unlikely(packet == NULL)) { 408 DCCP_CRIT("packet history - out of memory!"); 409 return; 410 } 411 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet); 412 413 dccp_timestamp(sk, &now); 414 packet->dccphtx_tstamp = now; 415 packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss; 416 packet->dccphtx_rtt = hctx->ccid3hctx_rtt; 417 packet->dccphtx_sent = 1; 418 } 419 420 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) 421 { 422 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 423 struct ccid3_options_received *opt_recv; 424 struct dccp_tx_hist_entry *packet; 425 struct timeval now; 426 unsigned long t_nfb; 427 u32 pinv, r_sample; 428 429 BUG_ON(hctx == NULL); 430 431 /* we are only interested in ACKs */ 432 if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || 433 DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) 434 return; 435 436 opt_recv = &hctx->ccid3hctx_options_received; 437 438 switch (hctx->ccid3hctx_state) { 439 case TFRC_SSTATE_NO_FBACK: 440 case TFRC_SSTATE_FBACK: 441 /* get packet from history to look up t_recvdata */ 442 packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist, 443 DCCP_SKB_CB(skb)->dccpd_ack_seq); 444 if (unlikely(packet == NULL)) { 445 DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist " 446 "in history!\n", dccp_role(sk), sk, 447 (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, 448 dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type)); 449 return; 450 } 451 452 /* Update receive rate in units of 64 * bytes/second */ 453 hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; 454 hctx->ccid3hctx_x_recv <<= 6; 455 456 /* Update loss event rate */ 457 pinv = opt_recv->ccid3or_loss_event_rate; 458 if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ 459 hctx->ccid3hctx_p = 0; 460 else /* can not exceed 100% */ 461 hctx->ccid3hctx_p = 1000000 / pinv; 462 463 dccp_timestamp(sk, &now); 464 465 /* 466 * Calculate new round trip sample as per [RFC 3448, 4.3] by 467 * R_sample = (now - t_recvdata) - t_elapsed 468 */ 469 r_sample = dccp_sample_rtt(sk, &now, &packet->dccphtx_tstamp); 470 471 /* 472 * Update RTT estimate by 473 * If (No feedback recv) 474 * R = R_sample; 475 * Else 476 * R = q * R + (1 - q) * R_sample; 477 * 478 * q is a constant, RFC 3448 recomments 0.9 479 */ 480 if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { 481 /* 482 * Larger Initial Windows [RFC 4342, sec. 5] 483 */ 484 hctx->ccid3hctx_rtt = r_sample; 485 hctx->ccid3hctx_x = rfc3390_initial_rate(sk); 486 hctx->ccid3hctx_t_ld = now; 487 488 ccid3_update_send_interval(hctx); 489 490 ccid3_pr_debug("%s(%p), s=%u, MSS=%u, " 491 "R_sample=%uus, X=%u\n", dccp_role(sk), 492 sk, hctx->ccid3hctx_s, 493 dccp_sk(sk)->dccps_mss_cache, r_sample, 494 (unsigned)(hctx->ccid3hctx_x >> 6)); 495 496 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); 497 } else { 498 hctx->ccid3hctx_rtt = (9 * hctx->ccid3hctx_rtt + 499 r_sample) / 10; 500 501 /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ 502 if (hctx->ccid3hctx_p > 0) 503 hctx->ccid3hctx_x_calc = 504 tfrc_calc_x(hctx->ccid3hctx_s, 505 hctx->ccid3hctx_rtt, 506 hctx->ccid3hctx_p); 507 ccid3_hc_tx_update_x(sk, &now); 508 509 ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " 510 "p=%u, X_calc=%u, X_recv=%u, X=%u\n", 511 dccp_role(sk), 512 sk, hctx->ccid3hctx_rtt, r_sample, 513 hctx->ccid3hctx_s, hctx->ccid3hctx_p, 514 hctx->ccid3hctx_x_calc, 515 (unsigned)(hctx->ccid3hctx_x_recv >> 6), 516 (unsigned)(hctx->ccid3hctx_x >> 6)); 517 } 518 519 /* unschedule no feedback timer */ 520 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); 521 522 /* remove all packets older than the one acked from history */ 523 dccp_tx_hist_purge_older(ccid3_tx_hist, 524 &hctx->ccid3hctx_hist, packet); 525 /* 526 * As we have calculated new ipi, delta, t_nom it is possible 527 * that we now can send a packet, so wake up dccp_wait_for_ccid 528 */ 529 sk->sk_write_space(sk); 530 531 /* 532 * Update timeout interval for the nofeedback timer. 533 * We use a configuration option to increase the lower bound. 534 * This can help avoid triggering the nofeedback timer too 535 * often ('spinning') on LANs with small RTTs. 536 */ 537 hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, 538 CONFIG_IP_DCCP_CCID3_RTO * 539 (USEC_PER_SEC/1000)); 540 /* 541 * Schedule no feedback timer to expire in 542 * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) 543 */ 544 t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); 545 546 ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " 547 "expire in %lu jiffies (%luus)\n", 548 dccp_role(sk), 549 sk, usecs_to_jiffies(t_nfb), t_nfb); 550 551 sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, 552 jiffies + usecs_to_jiffies(t_nfb)); 553 554 /* set idle flag */ 555 hctx->ccid3hctx_idle = 1; 556 break; 557 case TFRC_SSTATE_NO_SENT: /* fall through */ 558 case TFRC_SSTATE_TERM: /* ignore feedback when closing */ 559 break; 560 } 561 } 562 563 static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, 564 unsigned char len, u16 idx, 565 unsigned char *value) 566 { 567 int rc = 0; 568 const struct dccp_sock *dp = dccp_sk(sk); 569 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 570 struct ccid3_options_received *opt_recv; 571 572 BUG_ON(hctx == NULL); 573 574 opt_recv = &hctx->ccid3hctx_options_received; 575 576 if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { 577 opt_recv->ccid3or_seqno = dp->dccps_gsr; 578 opt_recv->ccid3or_loss_event_rate = ~0; 579 opt_recv->ccid3or_loss_intervals_idx = 0; 580 opt_recv->ccid3or_loss_intervals_len = 0; 581 opt_recv->ccid3or_receive_rate = 0; 582 } 583 584 switch (option) { 585 case TFRC_OPT_LOSS_EVENT_RATE: 586 if (unlikely(len != 4)) { 587 DCCP_WARN("%s(%p), invalid len %d " 588 "for TFRC_OPT_LOSS_EVENT_RATE\n", 589 dccp_role(sk), sk, len); 590 rc = -EINVAL; 591 } else { 592 opt_recv->ccid3or_loss_event_rate = 593 ntohl(*(__be32 *)value); 594 ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", 595 dccp_role(sk), sk, 596 opt_recv->ccid3or_loss_event_rate); 597 } 598 break; 599 case TFRC_OPT_LOSS_INTERVALS: 600 opt_recv->ccid3or_loss_intervals_idx = idx; 601 opt_recv->ccid3or_loss_intervals_len = len; 602 ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", 603 dccp_role(sk), sk, 604 opt_recv->ccid3or_loss_intervals_idx, 605 opt_recv->ccid3or_loss_intervals_len); 606 break; 607 case TFRC_OPT_RECEIVE_RATE: 608 if (unlikely(len != 4)) { 609 DCCP_WARN("%s(%p), invalid len %d " 610 "for TFRC_OPT_RECEIVE_RATE\n", 611 dccp_role(sk), sk, len); 612 rc = -EINVAL; 613 } else { 614 opt_recv->ccid3or_receive_rate = 615 ntohl(*(__be32 *)value); 616 ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", 617 dccp_role(sk), sk, 618 opt_recv->ccid3or_receive_rate); 619 } 620 break; 621 } 622 623 return rc; 624 } 625 626 static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) 627 { 628 struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); 629 630 hctx->ccid3hctx_s = 0; 631 hctx->ccid3hctx_rtt = 0; 632 hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT; 633 INIT_LIST_HEAD(&hctx->ccid3hctx_hist); 634 635 hctx->ccid3hctx_no_feedback_timer.function = 636 ccid3_hc_tx_no_feedback_timer; 637 hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk; 638 init_timer(&hctx->ccid3hctx_no_feedback_timer); 639 640 return 0; 641 } 642 643 static void ccid3_hc_tx_exit(struct sock *sk) 644 { 645 struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 646 647 BUG_ON(hctx == NULL); 648 649 ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); 650 sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); 651 652 /* Empty packet history */ 653 dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist); 654 } 655 656 static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) 657 { 658 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 659 660 /* Listen socks doesn't have a private CCID block */ 661 if (sk->sk_state == DCCP_LISTEN) 662 return; 663 664 BUG_ON(hctx == NULL); 665 666 info->tcpi_rto = hctx->ccid3hctx_t_rto; 667 info->tcpi_rtt = hctx->ccid3hctx_rtt; 668 } 669 670 static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, 671 u32 __user *optval, int __user *optlen) 672 { 673 const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); 674 const void *val; 675 676 /* Listen socks doesn't have a private CCID block */ 677 if (sk->sk_state == DCCP_LISTEN) 678 return -EINVAL; 679 680 switch (optname) { 681 case DCCP_SOCKOPT_CCID_TX_INFO: 682 if (len < sizeof(hctx->ccid3hctx_tfrc)) 683 return -EINVAL; 684 len = sizeof(hctx->ccid3hctx_tfrc); 685 val = &hctx->ccid3hctx_tfrc; 686 break; 687 default: 688 return -ENOPROTOOPT; 689 } 690 691 if (put_user(len, optlen) || copy_to_user(optval, val, len)) 692 return -EFAULT; 693 694 return 0; 695 } 696 697 /* 698 * Receiver Half-Connection Routines 699 */ 700 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG 701 static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) 702 { 703 static char *ccid3_rx_state_names[] = { 704 [TFRC_RSTATE_NO_DATA] = "NO_DATA", 705 [TFRC_RSTATE_DATA] = "DATA", 706 [TFRC_RSTATE_TERM] = "TERM", 707 }; 708 709 return ccid3_rx_state_names[state]; 710 } 711 #endif 712 713 static void ccid3_hc_rx_set_state(struct sock *sk, 714 enum ccid3_hc_rx_states state) 715 { 716 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 717 enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state; 718 719 ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", 720 dccp_role(sk), sk, ccid3_rx_state_name(oldstate), 721 ccid3_rx_state_name(state)); 722 WARN_ON(state == oldstate); 723 hcrx->ccid3hcrx_state = state; 724 } 725 726 static inline void ccid3_hc_rx_update_s(struct ccid3_hc_rx_sock *hcrx, int len) 727 { 728 if (unlikely(len == 0)) /* don't update on empty packets (e.g. ACKs) */ 729 ccid3_pr_debug("Packet payload length is 0 - not updating\n"); 730 else 731 hcrx->ccid3hcrx_s = hcrx->ccid3hcrx_s == 0 ? len : 732 (9 * hcrx->ccid3hcrx_s + len) / 10; 733 } 734 735 static void ccid3_hc_rx_send_feedback(struct sock *sk) 736 { 737 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 738 struct dccp_sock *dp = dccp_sk(sk); 739 struct dccp_rx_hist_entry *packet; 740 struct timeval now; 741 suseconds_t delta; 742 743 ccid3_pr_debug("%s(%p) - entry \n", dccp_role(sk), sk); 744 745 dccp_timestamp(sk, &now); 746 747 switch (hcrx->ccid3hcrx_state) { 748 case TFRC_RSTATE_NO_DATA: 749 hcrx->ccid3hcrx_x_recv = 0; 750 break; 751 case TFRC_RSTATE_DATA: 752 delta = timeval_delta(&now, 753 &hcrx->ccid3hcrx_tstamp_last_feedback); 754 DCCP_BUG_ON(delta < 0); 755 hcrx->ccid3hcrx_x_recv = 756 scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); 757 break; 758 case TFRC_RSTATE_TERM: 759 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); 760 return; 761 } 762 763 packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist); 764 if (unlikely(packet == NULL)) { 765 DCCP_WARN("%s(%p), no data packet in history!\n", 766 dccp_role(sk), sk); 767 return; 768 } 769 770 hcrx->ccid3hcrx_tstamp_last_feedback = now; 771 hcrx->ccid3hcrx_ccval_last_counter = packet->dccphrx_ccval; 772 hcrx->ccid3hcrx_bytes_recv = 0; 773 774 /* Elapsed time information [RFC 4340, 13.2] in units of 10 * usecs */ 775 delta = timeval_delta(&now, &packet->dccphrx_tstamp); 776 DCCP_BUG_ON(delta < 0); 777 hcrx->ccid3hcrx_elapsed_time = delta / 10; 778 779 if (hcrx->ccid3hcrx_p == 0) 780 hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */ 781 else if (hcrx->ccid3hcrx_p > 1000000) { 782 DCCP_WARN("p (%u) > 100%%\n", hcrx->ccid3hcrx_p); 783 hcrx->ccid3hcrx_pinv = 1; /* use 100% in this case */ 784 } else 785 hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p; 786 787 dp->dccps_hc_rx_insert_options = 1; 788 dccp_send_ack(sk); 789 } 790 791 static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) 792 { 793 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 794 __be32 x_recv, pinv; 795 796 BUG_ON(hcrx == NULL); 797 798 if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) 799 return 0; 800 801 DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_ccval_last_counter; 802 803 if (dccp_packet_without_ack(skb)) 804 return 0; 805 806 x_recv = htonl(hcrx->ccid3hcrx_x_recv); 807 pinv = htonl(hcrx->ccid3hcrx_pinv); 808 809 if ((hcrx->ccid3hcrx_elapsed_time != 0 && 810 dccp_insert_option_elapsed_time(sk, skb, 811 hcrx->ccid3hcrx_elapsed_time)) || 812 dccp_insert_option_timestamp(sk, skb) || 813 dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, 814 &pinv, sizeof(pinv)) || 815 dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE, 816 &x_recv, sizeof(x_recv))) 817 return -1; 818 819 return 0; 820 } 821 822 /* calculate first loss interval 823 * 824 * returns estimated loss interval in usecs */ 825 826 static u32 ccid3_hc_rx_calc_first_li(struct sock *sk) 827 { 828 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 829 struct dccp_rx_hist_entry *entry, *next, *tail = NULL; 830 u32 x_recv, p; 831 suseconds_t rtt, delta; 832 struct timeval tstamp = { 0, }; 833 int interval = 0; 834 int win_count = 0; 835 int step = 0; 836 u64 fval; 837 838 list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist, 839 dccphrx_node) { 840 if (dccp_rx_hist_entry_data_packet(entry)) { 841 tail = entry; 842 843 switch (step) { 844 case 0: 845 tstamp = entry->dccphrx_tstamp; 846 win_count = entry->dccphrx_ccval; 847 step = 1; 848 break; 849 case 1: 850 interval = win_count - entry->dccphrx_ccval; 851 if (interval < 0) 852 interval += TFRC_WIN_COUNT_LIMIT; 853 if (interval > 4) 854 goto found; 855 break; 856 } 857 } 858 } 859 860 if (unlikely(step == 0)) { 861 DCCP_WARN("%s(%p), packet history has no data packets!\n", 862 dccp_role(sk), sk); 863 return ~0; 864 } 865 866 if (unlikely(interval == 0)) { 867 DCCP_WARN("%s(%p), Could not find a win_count interval > 0." 868 "Defaulting to 1\n", dccp_role(sk), sk); 869 interval = 1; 870 } 871 found: 872 if (!tail) { 873 DCCP_CRIT("tail is null\n"); 874 return ~0; 875 } 876 877 delta = timeval_delta(&tstamp, &tail->dccphrx_tstamp); 878 DCCP_BUG_ON(delta < 0); 879 880 rtt = delta * 4 / interval; 881 ccid3_pr_debug("%s(%p), approximated RTT to %dus\n", 882 dccp_role(sk), sk, (int)rtt); 883 884 /* 885 * Determine the length of the first loss interval via inverse lookup. 886 * Assume that X_recv can be computed by the throughput equation 887 * s 888 * X_recv = -------- 889 * R * fval 890 * Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1]. 891 */ 892 if (rtt == 0) { /* would result in divide-by-zero */ 893 DCCP_WARN("RTT==0\n"); 894 return ~0; 895 } 896 897 dccp_timestamp(sk, &tstamp); 898 delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback); 899 DCCP_BUG_ON(delta <= 0); 900 901 x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); 902 if (x_recv == 0) { /* would also trigger divide-by-zero */ 903 DCCP_WARN("X_recv==0\n"); 904 if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) { 905 DCCP_BUG("stored value of X_recv is zero"); 906 return ~0; 907 } 908 } 909 910 fval = scaled_div(hcrx->ccid3hcrx_s, rtt); 911 fval = scaled_div32(fval, x_recv); 912 p = tfrc_calc_x_reverse_lookup(fval); 913 914 ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " 915 "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); 916 917 if (p == 0) 918 return ~0; 919 else 920 return 1000000 / p; 921 } 922 923 static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss) 924 { 925 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 926 struct dccp_li_hist_entry *head; 927 u64 seq_temp; 928 929 if (list_empty(&hcrx->ccid3hcrx_li_hist)) { 930 if (!dccp_li_hist_interval_new(ccid3_li_hist, 931 &hcrx->ccid3hcrx_li_hist, seq_loss, win_loss)) 932 return; 933 934 head = list_entry(hcrx->ccid3hcrx_li_hist.next, 935 struct dccp_li_hist_entry, dccplih_node); 936 head->dccplih_interval = ccid3_hc_rx_calc_first_li(sk); 937 } else { 938 struct dccp_li_hist_entry *entry; 939 struct list_head *tail; 940 941 head = list_entry(hcrx->ccid3hcrx_li_hist.next, 942 struct dccp_li_hist_entry, dccplih_node); 943 /* FIXME win count check removed as was wrong */ 944 /* should make this check with receive history */ 945 /* and compare there as per section 10.2 of RFC4342 */ 946 947 /* new loss event detected */ 948 /* calculate last interval length */ 949 seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss); 950 entry = dccp_li_hist_entry_new(ccid3_li_hist, GFP_ATOMIC); 951 952 if (entry == NULL) { 953 DCCP_BUG("out of memory - can not allocate entry"); 954 return; 955 } 956 957 list_add(&entry->dccplih_node, &hcrx->ccid3hcrx_li_hist); 958 959 tail = hcrx->ccid3hcrx_li_hist.prev; 960 list_del(tail); 961 kmem_cache_free(ccid3_li_hist->dccplih_slab, tail); 962 963 /* Create the newest interval */ 964 entry->dccplih_seqno = seq_loss; 965 entry->dccplih_interval = seq_temp; 966 entry->dccplih_win_count = win_loss; 967 } 968 } 969 970 static int ccid3_hc_rx_detect_loss(struct sock *sk, 971 struct dccp_rx_hist_entry *packet) 972 { 973 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 974 struct dccp_rx_hist_entry *rx_hist = 975 dccp_rx_hist_head(&hcrx->ccid3hcrx_hist); 976 u64 seqno = packet->dccphrx_seqno; 977 u64 tmp_seqno; 978 int loss = 0; 979 u8 ccval; 980 981 982 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss; 983 984 if (!rx_hist || 985 follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) { 986 hcrx->ccid3hcrx_seqno_nonloss = seqno; 987 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval; 988 goto detect_out; 989 } 990 991 992 while (dccp_delta_seqno(hcrx->ccid3hcrx_seqno_nonloss, seqno) 993 > TFRC_RECV_NUM_LATE_LOSS) { 994 loss = 1; 995 ccid3_hc_rx_update_li(sk, hcrx->ccid3hcrx_seqno_nonloss, 996 hcrx->ccid3hcrx_ccval_nonloss); 997 tmp_seqno = hcrx->ccid3hcrx_seqno_nonloss; 998 dccp_inc_seqno(&tmp_seqno); 999 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno; 1000 dccp_inc_seqno(&tmp_seqno); 1001 while (dccp_rx_hist_find_entry(&hcrx->ccid3hcrx_hist, 1002 tmp_seqno, &ccval)) { 1003 hcrx->ccid3hcrx_seqno_nonloss = tmp_seqno; 1004 hcrx->ccid3hcrx_ccval_nonloss = ccval; 1005 dccp_inc_seqno(&tmp_seqno); 1006 } 1007 } 1008 1009 /* FIXME - this code could be simplified with above while */ 1010 /* but works at moment */ 1011 if (follows48(packet->dccphrx_seqno, hcrx->ccid3hcrx_seqno_nonloss)) { 1012 hcrx->ccid3hcrx_seqno_nonloss = seqno; 1013 hcrx->ccid3hcrx_ccval_nonloss = packet->dccphrx_ccval; 1014 } 1015 1016 detect_out: 1017 dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist, 1018 &hcrx->ccid3hcrx_li_hist, packet, 1019 hcrx->ccid3hcrx_seqno_nonloss); 1020 return loss; 1021 } 1022 1023 static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) 1024 { 1025 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 1026 const struct dccp_options_received *opt_recv; 1027 struct dccp_rx_hist_entry *packet; 1028 struct timeval now; 1029 u32 p_prev, r_sample, rtt_prev; 1030 int loss, payload_size; 1031 1032 BUG_ON(hcrx == NULL); 1033 1034 opt_recv = &dccp_sk(sk)->dccps_options_received; 1035 1036 switch (DCCP_SKB_CB(skb)->dccpd_type) { 1037 case DCCP_PKT_ACK: 1038 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA) 1039 return; 1040 case DCCP_PKT_DATAACK: 1041 if (opt_recv->dccpor_timestamp_echo == 0) 1042 break; 1043 rtt_prev = hcrx->ccid3hcrx_rtt; 1044 dccp_timestamp(sk, &now); 1045 r_sample = dccp_sample_rtt(sk, &now, NULL); 1046 1047 if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA) 1048 hcrx->ccid3hcrx_rtt = r_sample; 1049 else 1050 hcrx->ccid3hcrx_rtt = (hcrx->ccid3hcrx_rtt * 9) / 10 + 1051 r_sample / 10; 1052 1053 if (rtt_prev != hcrx->ccid3hcrx_rtt) 1054 ccid3_pr_debug("%s(%p), New RTT=%uus, elapsed time=%u\n", 1055 dccp_role(sk), sk, hcrx->ccid3hcrx_rtt, 1056 opt_recv->dccpor_elapsed_time); 1057 break; 1058 case DCCP_PKT_DATA: 1059 break; 1060 default: /* We're not interested in other packet types, move along */ 1061 return; 1062 } 1063 1064 packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp, 1065 skb, GFP_ATOMIC); 1066 if (unlikely(packet == NULL)) { 1067 DCCP_WARN("%s(%p), Not enough mem to add rx packet " 1068 "to history, consider it lost!\n", dccp_role(sk), sk); 1069 return; 1070 } 1071 1072 loss = ccid3_hc_rx_detect_loss(sk, packet); 1073 1074 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK) 1075 return; 1076 1077 payload_size = skb->len - dccp_hdr(skb)->dccph_doff * 4; 1078 ccid3_hc_rx_update_s(hcrx, payload_size); 1079 1080 switch (hcrx->ccid3hcrx_state) { 1081 case TFRC_RSTATE_NO_DATA: 1082 ccid3_pr_debug("%s(%p, state=%s), skb=%p, sending initial " 1083 "feedback\n", dccp_role(sk), sk, 1084 dccp_state_name(sk->sk_state), skb); 1085 ccid3_hc_rx_send_feedback(sk); 1086 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); 1087 return; 1088 case TFRC_RSTATE_DATA: 1089 hcrx->ccid3hcrx_bytes_recv += payload_size; 1090 if (loss) 1091 break; 1092 1093 dccp_timestamp(sk, &now); 1094 if ((timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) - 1095 (suseconds_t)hcrx->ccid3hcrx_rtt) >= 0) { 1096 hcrx->ccid3hcrx_tstamp_last_ack = now; 1097 ccid3_hc_rx_send_feedback(sk); 1098 } 1099 return; 1100 case TFRC_RSTATE_TERM: 1101 DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); 1102 return; 1103 } 1104 1105 /* Dealing with packet loss */ 1106 ccid3_pr_debug("%s(%p, state=%s), data loss! Reacting...\n", 1107 dccp_role(sk), sk, dccp_state_name(sk->sk_state)); 1108 1109 p_prev = hcrx->ccid3hcrx_p; 1110 1111 /* Calculate loss event rate */ 1112 if (!list_empty(&hcrx->ccid3hcrx_li_hist)) { 1113 u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist); 1114 1115 /* Scaling up by 1000000 as fixed decimal */ 1116 if (i_mean != 0) 1117 hcrx->ccid3hcrx_p = 1000000 / i_mean; 1118 } else 1119 DCCP_BUG("empty loss history"); 1120 1121 if (hcrx->ccid3hcrx_p > p_prev) { 1122 ccid3_hc_rx_send_feedback(sk); 1123 return; 1124 } 1125 } 1126 1127 static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) 1128 { 1129 struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid); 1130 1131 ccid3_pr_debug("entry\n"); 1132 1133 hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA; 1134 INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist); 1135 INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist); 1136 dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack); 1137 hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack; 1138 hcrx->ccid3hcrx_s = 0; 1139 hcrx->ccid3hcrx_rtt = 0; 1140 return 0; 1141 } 1142 1143 static void ccid3_hc_rx_exit(struct sock *sk) 1144 { 1145 struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 1146 1147 BUG_ON(hcrx == NULL); 1148 1149 ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); 1150 1151 /* Empty packet history */ 1152 dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist); 1153 1154 /* Empty loss interval history */ 1155 dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist); 1156 } 1157 1158 static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) 1159 { 1160 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 1161 1162 /* Listen socks doesn't have a private CCID block */ 1163 if (sk->sk_state == DCCP_LISTEN) 1164 return; 1165 1166 BUG_ON(hcrx == NULL); 1167 1168 info->tcpi_ca_state = hcrx->ccid3hcrx_state; 1169 info->tcpi_options |= TCPI_OPT_TIMESTAMPS; 1170 info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt; 1171 } 1172 1173 static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, 1174 u32 __user *optval, int __user *optlen) 1175 { 1176 const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); 1177 const void *val; 1178 1179 /* Listen socks doesn't have a private CCID block */ 1180 if (sk->sk_state == DCCP_LISTEN) 1181 return -EINVAL; 1182 1183 switch (optname) { 1184 case DCCP_SOCKOPT_CCID_RX_INFO: 1185 if (len < sizeof(hcrx->ccid3hcrx_tfrc)) 1186 return -EINVAL; 1187 len = sizeof(hcrx->ccid3hcrx_tfrc); 1188 val = &hcrx->ccid3hcrx_tfrc; 1189 break; 1190 default: 1191 return -ENOPROTOOPT; 1192 } 1193 1194 if (put_user(len, optlen) || copy_to_user(optval, val, len)) 1195 return -EFAULT; 1196 1197 return 0; 1198 } 1199 1200 static struct ccid_operations ccid3 = { 1201 .ccid_id = DCCPC_CCID3, 1202 .ccid_name = "ccid3", 1203 .ccid_owner = THIS_MODULE, 1204 .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), 1205 .ccid_hc_tx_init = ccid3_hc_tx_init, 1206 .ccid_hc_tx_exit = ccid3_hc_tx_exit, 1207 .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, 1208 .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, 1209 .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, 1210 .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, 1211 .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), 1212 .ccid_hc_rx_init = ccid3_hc_rx_init, 1213 .ccid_hc_rx_exit = ccid3_hc_rx_exit, 1214 .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, 1215 .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, 1216 .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, 1217 .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, 1218 .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, 1219 .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, 1220 }; 1221 1222 #ifdef CONFIG_IP_DCCP_CCID3_DEBUG 1223 module_param(ccid3_debug, int, 0444); 1224 MODULE_PARM_DESC(ccid3_debug, "Enable debug messages"); 1225 #endif 1226 1227 static __init int ccid3_module_init(void) 1228 { 1229 int rc = -ENOBUFS; 1230 1231 ccid3_rx_hist = dccp_rx_hist_new("ccid3"); 1232 if (ccid3_rx_hist == NULL) 1233 goto out; 1234 1235 ccid3_tx_hist = dccp_tx_hist_new("ccid3"); 1236 if (ccid3_tx_hist == NULL) 1237 goto out_free_rx; 1238 1239 ccid3_li_hist = dccp_li_hist_new("ccid3"); 1240 if (ccid3_li_hist == NULL) 1241 goto out_free_tx; 1242 1243 rc = ccid_register(&ccid3); 1244 if (rc != 0) 1245 goto out_free_loss_interval_history; 1246 out: 1247 return rc; 1248 1249 out_free_loss_interval_history: 1250 dccp_li_hist_delete(ccid3_li_hist); 1251 ccid3_li_hist = NULL; 1252 out_free_tx: 1253 dccp_tx_hist_delete(ccid3_tx_hist); 1254 ccid3_tx_hist = NULL; 1255 out_free_rx: 1256 dccp_rx_hist_delete(ccid3_rx_hist); 1257 ccid3_rx_hist = NULL; 1258 goto out; 1259 } 1260 module_init(ccid3_module_init); 1261 1262 static __exit void ccid3_module_exit(void) 1263 { 1264 ccid_unregister(&ccid3); 1265 1266 if (ccid3_tx_hist != NULL) { 1267 dccp_tx_hist_delete(ccid3_tx_hist); 1268 ccid3_tx_hist = NULL; 1269 } 1270 if (ccid3_rx_hist != NULL) { 1271 dccp_rx_hist_delete(ccid3_rx_hist); 1272 ccid3_rx_hist = NULL; 1273 } 1274 if (ccid3_li_hist != NULL) { 1275 dccp_li_hist_delete(ccid3_li_hist); 1276 ccid3_li_hist = NULL; 1277 } 1278 } 1279 module_exit(ccid3_module_exit); 1280 1281 MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, " 1282 "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>"); 1283 MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID"); 1284 MODULE_LICENSE("GPL"); 1285 MODULE_ALIAS("net-dccp-ccid-3"); 1286