| /* |
| * 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 |
| * |
| * BUGS: |
| * - sequence number wrapping |
| */ |
| |
| #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(seqp->ccid2s_seq <= prev->ccid2s_seq); |
| 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, int num, |
| gfp_t gfp) |
| { |
| 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(sizeof(*seqp) * num, gfp); |
| if (seqp == NULL) |
| return -ENOMEM; |
| |
| for (i = 0; i < (num - 1); i++) { |
| seqp[i].ccid2s_next = &seqp[i + 1]; |
| seqp[i + 1].ccid2s_prev = &seqp[i]; |
| } |
| seqp[num - 1].ccid2s_next = seqp; |
| seqp->ccid2s_prev = &seqp[num - 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[num - 1]; |
| seqp[num - 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; |
| |
| switch (DCCP_SKB_CB(skb)->dccpd_type) { |
| case 0: /* XXX data packets from userland come through like this */ |
| case DCCP_PKT_DATA: |
| case DCCP_PKT_DATAACK: |
| break; |
| /* No congestion control on other packets */ |
| default: |
| return 0; |
| } |
| |
| hctx = ccid2_hc_tx_sk(sk); |
| |
| ccid2_pr_debug("pipe=%d cwnd=%d\n", hctx->ccid2hctx_pipe, |
| hctx->ccid2hctx_cwnd); |
| |
| if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) { |
| /* OK we can send... make sure previous packet was sent off */ |
| if (!hctx->ccid2hctx_sendwait) { |
| hctx->ccid2hctx_sendwait = 1; |
| return 0; |
| } |
| } |
| |
| return 1; /* XXX CCID should dequeue when ready instead of polling */ |
| } |
| |
| static void ccid2_change_l_ack_ratio(struct sock *sk, int val) |
| { |
| struct dccp_sock *dp = dccp_sk(sk); |
| /* |
| * XXX I don't really agree with val != 2. If cwnd is 1, ack ratio |
| * should be 1... it shouldn't be allowed to become 2. |
| * -sorbo. |
| */ |
| if (val != 2) { |
| const struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
| int max = hctx->ccid2hctx_cwnd / 2; |
| |
| /* round up */ |
| if (hctx->ccid2hctx_cwnd & 1) |
| max++; |
| |
| if (val > max) |
| val = max; |
| } |
| |
| ccid2_pr_debug("changing local ack ratio to %d\n", val); |
| WARN_ON(val <= 0); |
| dp->dccps_l_ack_ratio = val; |
| } |
| |
| static void ccid2_change_cwnd(struct ccid2_hc_tx_sock *hctx, int val) |
| { |
| if (val == 0) |
| val = 1; |
| |
| /* XXX do we need to change ack ratio? */ |
| ccid2_pr_debug("change cwnd to %d\n", val); |
| |
| BUG_ON(val < 1); |
| hctx->ccid2hctx_cwnd = 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_change_pipe(struct ccid2_hc_tx_sock *hctx, long val) |
| { |
| hctx->ccid2hctx_pipe = 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 */ |
| ccid2_change_pipe(hctx, 0); |
| hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1; |
| if (hctx->ccid2hctx_ssthresh < 2) |
| hctx->ccid2hctx_ssthresh = 2; |
| ccid2_change_cwnd(hctx, 1); |
| |
| /* clear state about stuff we sent */ |
| hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; |
| hctx->ccid2hctx_ssacks = 0; |
| hctx->ccid2hctx_acks = 0; |
| hctx->ccid2hctx_sent = 0; |
| |
| /* clear ack ratio state. */ |
| hctx->ccid2hctx_arsent = 0; |
| hctx->ccid2hctx_ackloss = 0; |
| 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; |
| u64 seq; |
| |
| ccid2_hc_tx_check_sanity(hctx); |
| |
| BUG_ON(!hctx->ccid2hctx_sendwait); |
| hctx->ccid2hctx_sendwait = 0; |
| ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe + 1); |
| BUG_ON(hctx->ccid2hctx_pipe < 0); |
| |
| /* There is an issue. What if another packet is sent between |
| * packet_send() and packet_sent(). Then the sequence number would be |
| * wrong. |
| * -sorbo. |
| */ |
| seq = dp->dccps_gss; |
| |
| hctx->ccid2hctx_seqh->ccid2s_seq = seq; |
| 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) { |
| int rc; |
| |
| ccid2_pr_debug("allocating more space in history\n"); |
| rc = ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, gfp_any()); |
| BUG_ON(rc); /* XXX what do we do? */ |
| |
| 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); |
| |
| hctx->ccid2hctx_sent++; |
| |
| /* 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*/ |
| } |
| } |
| |
| /* setup RTO timer */ |
| if (!timer_pending(&hctx->ccid2hctx_rtotimer)) |
| ccid2_start_rto_timer(sk); |
| |
| #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
| ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe); |
| ccid2_pr_debug("Sent: seq=%llu\n", (unsigned long long)seq); |
| 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); |
| |
| /* slow start */ |
| if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { |
| hctx->ccid2hctx_acks = 0; |
| |
| /* We can increase cwnd at most maxincr [ack_ratio/2] */ |
| if (*maxincr) { |
| /* increase every 2 acks */ |
| hctx->ccid2hctx_ssacks++; |
| if (hctx->ccid2hctx_ssacks == 2) { |
| ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd+1); |
| hctx->ccid2hctx_ssacks = 0; |
| *maxincr = *maxincr - 1; |
| } |
| } else { |
| /* increased cwnd enough for this single ack */ |
| hctx->ccid2hctx_ssacks = 0; |
| } |
| } else { |
| hctx->ccid2hctx_ssacks = 0; |
| hctx->ccid2hctx_acks++; |
| |
| if (hctx->ccid2hctx_acks >= hctx->ccid2hctx_cwnd) { |
| ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd + 1); |
| hctx->ccid2hctx_acks = 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); |
| hctx->ccid2hctx_sent = 0; |
| } |
| |
| /* 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); |
| |
| ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe-1); |
| BUG_ON(hctx->ccid2hctx_pipe < 0); |
| |
| if (hctx->ccid2hctx_pipe == 0) |
| ccid2_hc_tx_kill_rto_timer(sk); |
| } |
| |
| static void ccid2_congestion_event(struct ccid2_hc_tx_sock *hctx, |
| struct ccid2_seq *seqp) |
| { |
| 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; |
| |
| ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd >> 1); |
| hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd; |
| if (hctx->ccid2hctx_ssthresh < 2) |
| hctx->ccid2hctx_ssthresh = 2; |
| } |
| |
| 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 ((hctx->ccid2hctx_rpseq + 1) == seqno) |
| hctx->ccid2hctx_rpseq++; |
| /* 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 >= |
| hctx->ccid2hctx_numdupack) { |
| hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ |
| hctx->ccid2hctx_rpseq = 0; |
| |
| ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio << 1); |
| } |
| } |
| } |
| |
| /* 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; |
| } |
| } |
| |
| /* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for |
| * this single ack. I round up. |
| * -sorbo. |
| */ |
| maxincr = dp->dccps_l_ack_ratio >> 1; |
| maxincr++; |
| |
| /* 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; |
| |
| dccp_set_seqno(&ackno_end_rl, 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(hctx, |
| 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_next; |
| } |
| if (done) |
| break; |
| |
| |
| dccp_set_seqno(&ackno, 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 == hctx->ccid2hctx_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 == hctx->ccid2hctx_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(hctx, 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); |
| |
| ccid2_change_cwnd(hctx, 1); |
| /* Initialize ssthresh to infinity. This means that we will exit the |
| * initial slow-start after the first packet loss. This is what we |
| * want. |
| */ |
| hctx->ccid2hctx_ssthresh = ~0; |
| hctx->ccid2hctx_numdupack = 3; |
| hctx->ccid2hctx_seqbufc = 0; |
| |
| /* XXX init ~ to window size... */ |
| if (ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_ATOMIC) != 0) |
| return -ENOMEM; |
| |
| hctx->ccid2hctx_sent = 0; |
| hctx->ccid2hctx_rto = 3 * HZ; |
| ccid2_change_srtt(hctx, -1); |
| hctx->ccid2hctx_rttvar = -1; |
| hctx->ccid2hctx_lastrtt = 0; |
| hctx->ccid2hctx_rpdupack = -1; |
| hctx->ccid2hctx_last_cong = jiffies; |
| hctx->ccid2hctx_high_ack = 0; |
| |
| hctx->ccid2hctx_rtotimer.function = &ccid2_hc_tx_rto_expire; |
| hctx->ccid2hctx_rtotimer.data = (unsigned long)sk; |
| init_timer(&hctx->ccid2hctx_rtotimer); |
| |
| 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 = "ccid2", |
| .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"); |