/* * net/dccp/ccids/ccid2.c * * Copyright (c) 2005, 2006 Andrea Bittau <a.bittau@cs.ucl.ac.uk> * * Changes to meet Linux coding standards, and DCCP infrastructure fixes. * * Copyright (c) 2006 Arnaldo Carvalho de Melo <acme@conectiva.com.br> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* * This implementation should follow RFC 4341 */ #include "../ccid.h" #include "../dccp.h" #include "ccid2.h" #ifdef CONFIG_IP_DCCP_CCID2_DEBUG static int ccid2_debug; #define ccid2_pr_debug(format, a...) DCCP_PR_DEBUG(ccid2_debug, format, ##a) static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx) { int len = 0; int pipe = 0; struct ccid2_seq *seqp = hctx->ccid2hctx_seqh; /* there is data in the chain */ if (seqp != hctx->ccid2hctx_seqt) { seqp = seqp->ccid2s_prev; len++; if (!seqp->ccid2s_acked) pipe++; while (seqp != hctx->ccid2hctx_seqt) { struct ccid2_seq *prev = seqp->ccid2s_prev; len++; if (!prev->ccid2s_acked) pipe++; /* packets are sent sequentially */ BUG_ON(dccp_delta_seqno(seqp->ccid2s_seq, prev->ccid2s_seq ) >= 0); BUG_ON(time_before(seqp->ccid2s_sent, prev->ccid2s_sent)); seqp = prev; } } BUG_ON(pipe != hctx->ccid2hctx_pipe); ccid2_pr_debug("len of chain=%d\n", len); do { seqp = seqp->ccid2s_prev; len++; } while (seqp != hctx->ccid2hctx_seqh); ccid2_pr_debug("total len=%d\n", len); BUG_ON(len != hctx->ccid2hctx_seqbufc * CCID2_SEQBUF_LEN); } #else #define ccid2_pr_debug(format, a...) #define ccid2_hc_tx_check_sanity(hctx) #endif static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx) { struct ccid2_seq *seqp; int i; /* check if we have space to preserve the pointer to the buffer */ if (hctx->ccid2hctx_seqbufc >= (sizeof(hctx->ccid2hctx_seqbuf) / sizeof(struct ccid2_seq*))) return -ENOMEM; /* allocate buffer and initialize linked list */ seqp = kmalloc(CCID2_SEQBUF_LEN * sizeof(struct ccid2_seq), gfp_any()); if (seqp == NULL) return -ENOMEM; for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) { seqp[i].ccid2s_next = &seqp[i + 1]; seqp[i + 1].ccid2s_prev = &seqp[i]; } seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = seqp; seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; /* This is the first allocation. Initiate the head and tail. */ if (hctx->ccid2hctx_seqbufc == 0) hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqt = seqp; else { /* link the existing list with the one we just created */ hctx->ccid2hctx_seqh->ccid2s_next = seqp; seqp->ccid2s_prev = hctx->ccid2hctx_seqh; hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hctx->ccid2hctx_seqt; } /* store the original pointer to the buffer so we can free it */ hctx->ccid2hctx_seqbuf[hctx->ccid2hctx_seqbufc] = seqp; hctx->ccid2hctx_seqbufc++; return 0; } static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) return 0; return 1; /* XXX CCID should dequeue when ready instead of polling */ } static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val) { struct dccp_sock *dp = dccp_sk(sk); u32 max_ratio = DIV_ROUND_UP(ccid2_hc_tx_sk(sk)->ccid2hctx_cwnd, 2); /* * Ensure that Ack Ratio does not exceed ceil(cwnd/2), which is (2) from * RFC 4341, 6.1.2. We ignore the statement that Ack Ratio 2 is always * acceptable since this causes starvation/deadlock whenever cwnd < 2. * The same problem arises when Ack Ratio is 0 (ie. Ack Ratio disabled). */ if (val == 0 || val > max_ratio) { DCCP_WARN("Limiting Ack Ratio (%u) to %u\n", val, max_ratio); val = max_ratio; } if (val > 0xFFFF) /* RFC 4340, 11.3 */ val = 0xFFFF; if (val == dp->dccps_l_ack_ratio) return; ccid2_pr_debug("changing local ack ratio to %u\n", val); dp->dccps_l_ack_ratio = val; } static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val) { ccid2_pr_debug("change SRTT to %ld\n", val); hctx->ccid2hctx_srtt = val; } static void ccid2_start_rto_timer(struct sock *sk); static void ccid2_hc_tx_rto_expire(unsigned long data) { struct sock *sk = (struct sock *)data; struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); long s; bh_lock_sock(sk); if (sock_owned_by_user(sk)) { sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, jiffies + HZ / 5); goto out; } ccid2_pr_debug("RTO_EXPIRE\n"); ccid2_hc_tx_check_sanity(hctx); /* back-off timer */ hctx->ccid2hctx_rto <<= 1; s = hctx->ccid2hctx_rto / HZ; if (s > 60) hctx->ccid2hctx_rto = 60 * HZ; ccid2_start_rto_timer(sk); /* adjust pipe, cwnd etc */ hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd / 2; if (hctx->ccid2hctx_ssthresh < 2) hctx->ccid2hctx_ssthresh = 2; hctx->ccid2hctx_cwnd = 1; hctx->ccid2hctx_pipe = 0; /* clear state about stuff we sent */ hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; hctx->ccid2hctx_packets_acked = 0; /* clear ack ratio state. */ hctx->ccid2hctx_rpseq = 0; hctx->ccid2hctx_rpdupack = -1; ccid2_change_l_ack_ratio(sk, 1); ccid2_hc_tx_check_sanity(hctx); out: bh_unlock_sock(sk); sock_put(sk); } static void ccid2_start_rto_timer(struct sock *sk) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto); BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer)); sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, jiffies + hctx->ccid2hctx_rto); } static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) { struct dccp_sock *dp = dccp_sk(sk); struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); struct ccid2_seq *next; hctx->ccid2hctx_pipe++; hctx->ccid2hctx_seqh->ccid2s_seq = dp->dccps_gss; hctx->ccid2hctx_seqh->ccid2s_acked = 0; hctx->ccid2hctx_seqh->ccid2s_sent = jiffies; next = hctx->ccid2hctx_seqh->ccid2s_next; /* check if we need to alloc more space */ if (next == hctx->ccid2hctx_seqt) { if (ccid2_hc_tx_alloc_seq(hctx)) { DCCP_CRIT("packet history - out of memory!"); /* FIXME: find a more graceful way to bail out */ return; } next = hctx->ccid2hctx_seqh->ccid2s_next; BUG_ON(next == hctx->ccid2hctx_seqt); } hctx->ccid2hctx_seqh = next; ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd, hctx->ccid2hctx_pipe); /* * FIXME: The code below is broken and the variables have been removed * from the socket struct. The `ackloss' variable was always set to 0, * and with arsent there are several problems: * (i) it doesn't just count the number of Acks, but all sent packets; * (ii) it is expressed in # of packets, not # of windows, so the * comparison below uses the wrong formula: Appendix A of RFC 4341 * comes up with the number K = cwnd / (R^2 - R) of consecutive windows * of data with no lost or marked Ack packets. If arsent were the # of * consecutive Acks received without loss, then Ack Ratio needs to be * decreased by 1 when * arsent >= K * cwnd / R = cwnd^2 / (R^3 - R^2) * where cwnd / R is the number of Acks received per window of data * (cf. RFC 4341, App. A). The problems are that * - arsent counts other packets as well; * - the comparison uses a formula different from RFC 4341; * - computing a cubic/quadratic equation each time is too complicated. * Hence a different algorithm is needed. */ #if 0 /* Ack Ratio. Need to maintain a concept of how many windows we sent */ hctx->ccid2hctx_arsent++; /* We had an ack loss in this window... */ if (hctx->ccid2hctx_ackloss) { if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) { hctx->ccid2hctx_arsent = 0; hctx->ccid2hctx_ackloss = 0; } } else { /* No acks lost up to now... */ /* decrease ack ratio if enough packets were sent */ if (dp->dccps_l_ack_ratio > 1) { /* XXX don't calculate denominator each time */ int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - dp->dccps_l_ack_ratio; denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom; if (hctx->ccid2hctx_arsent >= denom) { ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); hctx->ccid2hctx_arsent = 0; } } else { /* we can't increase ack ratio further [1] */ hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ } } #endif /* setup RTO timer */ if (!timer_pending(&hctx->ccid2hctx_rtotimer)) ccid2_start_rto_timer(sk); #ifdef CONFIG_IP_DCCP_CCID2_DEBUG do { struct ccid2_seq *seqp = hctx->ccid2hctx_seqt; while (seqp != hctx->ccid2hctx_seqh) { ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n", (unsigned long long)seqp->ccid2s_seq, seqp->ccid2s_acked, seqp->ccid2s_sent); seqp = seqp->ccid2s_next; } } while (0); ccid2_pr_debug("=========\n"); ccid2_hc_tx_check_sanity(hctx); #endif } /* XXX Lame code duplication! * returns -1 if none was found. * else returns the next offset to use in the function call. */ static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, unsigned char **vec, unsigned char *veclen) { const struct dccp_hdr *dh = dccp_hdr(skb); unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); unsigned char *opt_ptr; const unsigned char *opt_end = (unsigned char *)dh + (dh->dccph_doff * 4); unsigned char opt, len; unsigned char *value; BUG_ON(offset < 0); options += offset; opt_ptr = options; if (opt_ptr >= opt_end) return -1; while (opt_ptr != opt_end) { opt = *opt_ptr++; len = 0; value = NULL; /* Check if this isn't a single byte option */ if (opt > DCCPO_MAX_RESERVED) { if (opt_ptr == opt_end) goto out_invalid_option; len = *opt_ptr++; if (len < 3) goto out_invalid_option; /* * Remove the type and len fields, leaving * just the value size */ len -= 2; value = opt_ptr; opt_ptr += len; if (opt_ptr > opt_end) goto out_invalid_option; } switch (opt) { case DCCPO_ACK_VECTOR_0: case DCCPO_ACK_VECTOR_1: *vec = value; *veclen = len; return offset + (opt_ptr - options); } } return -1; out_invalid_option: DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); return -1; } static void ccid2_hc_tx_kill_rto_timer(struct sock *sk) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer); ccid2_pr_debug("deleted RTO timer\n"); } static inline void ccid2_new_ack(struct sock *sk, struct ccid2_seq *seqp, unsigned int *maxincr) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { if (*maxincr > 0 && ++hctx->ccid2hctx_packets_acked == 2) { hctx->ccid2hctx_cwnd += 1; *maxincr -= 1; hctx->ccid2hctx_packets_acked = 0; } } else if (++hctx->ccid2hctx_packets_acked >= hctx->ccid2hctx_cwnd) { hctx->ccid2hctx_cwnd += 1; hctx->ccid2hctx_packets_acked = 0; } /* update RTO */ if (hctx->ccid2hctx_srtt == -1 || time_after(jiffies, hctx->ccid2hctx_lastrtt + hctx->ccid2hctx_srtt)) { unsigned long r = (long)jiffies - (long)seqp->ccid2s_sent; int s; /* first measurement */ if (hctx->ccid2hctx_srtt == -1) { ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n", r, jiffies, (unsigned long long)seqp->ccid2s_seq); ccid2_change_srtt(hctx, r); hctx->ccid2hctx_rttvar = r >> 1; } else { /* RTTVAR */ long tmp = hctx->ccid2hctx_srtt - r; long srtt; if (tmp < 0) tmp *= -1; tmp >>= 2; hctx->ccid2hctx_rttvar *= 3; hctx->ccid2hctx_rttvar >>= 2; hctx->ccid2hctx_rttvar += tmp; /* SRTT */ srtt = hctx->ccid2hctx_srtt; srtt *= 7; srtt >>= 3; tmp = r >> 3; srtt += tmp; ccid2_change_srtt(hctx, srtt); } s = hctx->ccid2hctx_rttvar << 2; /* clock granularity is 1 when based on jiffies */ if (!s) s = 1; hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s; /* must be at least a second */ s = hctx->ccid2hctx_rto / HZ; /* DCCP doesn't require this [but I like it cuz my code sux] */ #if 1 if (s < 1) hctx->ccid2hctx_rto = HZ; #endif /* max 60 seconds */ if (s > 60) hctx->ccid2hctx_rto = HZ * 60; hctx->ccid2hctx_lastrtt = jiffies; ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n", hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar, hctx->ccid2hctx_rto, HZ, r); } /* we got a new ack, so re-start RTO timer */ ccid2_hc_tx_kill_rto_timer(sk); ccid2_start_rto_timer(sk); } static void ccid2_hc_tx_dec_pipe(struct sock *sk) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); if (hctx->ccid2hctx_pipe == 0) DCCP_BUG("pipe == 0"); else hctx->ccid2hctx_pipe--; if (hctx->ccid2hctx_pipe == 0) ccid2_hc_tx_kill_rto_timer(sk); } static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); if (time_before(seqp->ccid2s_sent, hctx->ccid2hctx_last_cong)) { ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); return; } hctx->ccid2hctx_last_cong = jiffies; hctx->ccid2hctx_cwnd = hctx->ccid2hctx_cwnd / 2 ? : 1U; hctx->ccid2hctx_ssthresh = max(hctx->ccid2hctx_cwnd, 2U); /* Avoid spurious timeouts resulting from Ack Ratio > cwnd */ if (dccp_sk(sk)->dccps_l_ack_ratio > hctx->ccid2hctx_cwnd) ccid2_change_l_ack_ratio(sk, hctx->ccid2hctx_cwnd); } static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); u64 ackno, seqno; struct ccid2_seq *seqp; unsigned char *vector; unsigned char veclen; int offset = 0; int done = 0; unsigned int maxincr = 0; ccid2_hc_tx_check_sanity(hctx); /* check reverse path congestion */ seqno = DCCP_SKB_CB(skb)->dccpd_seq; /* XXX this whole "algorithm" is broken. Need to fix it to keep track * of the seqnos of the dupacks so that rpseq and rpdupack are correct * -sorbo. */ /* need to bootstrap */ if (hctx->ccid2hctx_rpdupack == -1) { hctx->ccid2hctx_rpdupack = 0; hctx->ccid2hctx_rpseq = seqno; } else { /* check if packet is consecutive */ if (dccp_delta_seqno(hctx->ccid2hctx_rpseq, seqno) == 1) hctx->ccid2hctx_rpseq = seqno; /* it's a later packet */ else if (after48(seqno, hctx->ccid2hctx_rpseq)) { hctx->ccid2hctx_rpdupack++; /* check if we got enough dupacks */ if (hctx->ccid2hctx_rpdupack >= NUMDUPACK) { hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ hctx->ccid2hctx_rpseq = 0; ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio); } } } /* check forward path congestion */ /* still didn't send out new data packets */ if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) return; switch (DCCP_SKB_CB(skb)->dccpd_type) { case DCCP_PKT_ACK: case DCCP_PKT_DATAACK: break; default: return; } ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; if (after48(ackno, hctx->ccid2hctx_high_ack)) hctx->ccid2hctx_high_ack = ackno; seqp = hctx->ccid2hctx_seqt; while (before48(seqp->ccid2s_seq, ackno)) { seqp = seqp->ccid2s_next; if (seqp == hctx->ccid2hctx_seqh) { seqp = hctx->ccid2hctx_seqh->ccid2s_prev; break; } } /* * In slow-start, cwnd can increase up to a maximum of Ack Ratio/2 * packets per acknowledgement. Rounding up avoids that cwnd is not * advanced when Ack Ratio is 1 and gives a slight edge otherwise. */ if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) maxincr = DIV_ROUND_UP(dp->dccps_l_ack_ratio, 2); /* go through all ack vectors */ while ((offset = ccid2_ackvector(sk, skb, offset, &vector, &veclen)) != -1) { /* go through this ack vector */ while (veclen--) { const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; u64 ackno_end_rl = SUB48(ackno, rl); ccid2_pr_debug("ackvec start:%llu end:%llu\n", (unsigned long long)ackno, (unsigned long long)ackno_end_rl); /* if the seqno we are analyzing is larger than the * current ackno, then move towards the tail of our * seqnos. */ while (after48(seqp->ccid2s_seq, ackno)) { if (seqp == hctx->ccid2hctx_seqt) { done = 1; break; } seqp = seqp->ccid2s_prev; } if (done) break; /* check all seqnos in the range of the vector * run length */ while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { const u8 state = *vector & DCCP_ACKVEC_STATE_MASK; /* new packet received or marked */ if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED && !seqp->ccid2s_acked) { if (state == DCCP_ACKVEC_STATE_ECN_MARKED) { ccid2_congestion_event(sk, seqp); } else ccid2_new_ack(sk, seqp, &maxincr); seqp->ccid2s_acked = 1; ccid2_pr_debug("Got ack for %llu\n", (unsigned long long)seqp->ccid2s_seq); ccid2_hc_tx_dec_pipe(sk); } if (seqp == hctx->ccid2hctx_seqt) { done = 1; break; } seqp = seqp->ccid2s_prev; } if (done) break; ackno = SUB48(ackno_end_rl, 1); vector++; } if (done) break; } /* The state about what is acked should be correct now * Check for NUMDUPACK */ seqp = hctx->ccid2hctx_seqt; while (before48(seqp->ccid2s_seq, hctx->ccid2hctx_high_ack)) { seqp = seqp->ccid2s_next; if (seqp == hctx->ccid2hctx_seqh) { seqp = hctx->ccid2hctx_seqh->ccid2s_prev; break; } } done = 0; while (1) { if (seqp->ccid2s_acked) { done++; if (done == NUMDUPACK) break; } if (seqp == hctx->ccid2hctx_seqt) break; seqp = seqp->ccid2s_prev; } /* If there are at least 3 acknowledgements, anything unacknowledged * below the last sequence number is considered lost */ if (done == NUMDUPACK) { struct ccid2_seq *last_acked = seqp; /* check for lost packets */ while (1) { if (!seqp->ccid2s_acked) { ccid2_pr_debug("Packet lost: %llu\n", (unsigned long long)seqp->ccid2s_seq); /* XXX need to traverse from tail -> head in * order to detect multiple congestion events in * one ack vector. */ ccid2_congestion_event(sk, seqp); ccid2_hc_tx_dec_pipe(sk); } if (seqp == hctx->ccid2hctx_seqt) break; seqp = seqp->ccid2s_prev; } hctx->ccid2hctx_seqt = last_acked; } /* trim acked packets in tail */ while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) { if (!hctx->ccid2hctx_seqt->ccid2s_acked) break; hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next; } ccid2_hc_tx_check_sanity(hctx); } static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) { struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid); struct dccp_sock *dp = dccp_sk(sk); u32 max_ratio; /* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */ hctx->ccid2hctx_ssthresh = ~0U; /* * RFC 4341, 5: "The cwnd parameter is initialized to at most four * packets for new connections, following the rules from [RFC3390]". * We need to convert the bytes of RFC3390 into the packets of RFC 4341. */ hctx->ccid2hctx_cwnd = clamp(4380U / dp->dccps_mss_cache, 2U, 4U); /* Make sure that Ack Ratio is enabled and within bounds. */ max_ratio = DIV_ROUND_UP(hctx->ccid2hctx_cwnd, 2); if (dp->dccps_l_ack_ratio == 0 || dp->dccps_l_ack_ratio > max_ratio) dp->dccps_l_ack_ratio = max_ratio; /* XXX init ~ to window size... */ if (ccid2_hc_tx_alloc_seq(hctx)) return -ENOMEM; hctx->ccid2hctx_rto = 3 * HZ; ccid2_change_srtt(hctx, -1); hctx->ccid2hctx_rttvar = -1; hctx->ccid2hctx_rpdupack = -1; hctx->ccid2hctx_last_cong = jiffies; setup_timer(&hctx->ccid2hctx_rtotimer, ccid2_hc_tx_rto_expire, (unsigned long)sk); ccid2_hc_tx_check_sanity(hctx); return 0; } static void ccid2_hc_tx_exit(struct sock *sk) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); int i; ccid2_hc_tx_kill_rto_timer(sk); for (i = 0; i < hctx->ccid2hctx_seqbufc; i++) kfree(hctx->ccid2hctx_seqbuf[i]); hctx->ccid2hctx_seqbufc = 0; } static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) { const struct dccp_sock *dp = dccp_sk(sk); struct ccid2_hc_rx_sock *hcrx = ccid2_hc_rx_sk(sk); switch (DCCP_SKB_CB(skb)->dccpd_type) { case DCCP_PKT_DATA: case DCCP_PKT_DATAACK: hcrx->ccid2hcrx_data++; if (hcrx->ccid2hcrx_data >= dp->dccps_r_ack_ratio) { dccp_send_ack(sk); hcrx->ccid2hcrx_data = 0; } break; } } static struct ccid_operations ccid2 = { .ccid_id = DCCPC_CCID2, .ccid_name = "TCP-like", .ccid_owner = THIS_MODULE, .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), .ccid_hc_tx_init = ccid2_hc_tx_init, .ccid_hc_tx_exit = ccid2_hc_tx_exit, .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, }; #ifdef CONFIG_IP_DCCP_CCID2_DEBUG module_param(ccid2_debug, bool, 0444); MODULE_PARM_DESC(ccid2_debug, "Enable debug messages"); #endif static __init int ccid2_module_init(void) { return ccid_register(&ccid2); } module_init(ccid2_module_init); static __exit void ccid2_module_exit(void) { ccid_unregister(&ccid2); } module_exit(ccid2_module_exit); MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>"); MODULE_DESCRIPTION("DCCP TCP-Like (CCID2) CCID"); MODULE_LICENSE("GPL"); MODULE_ALIAS("net-dccp-ccid-2");