/*
* This implementation should follow RFC 4341
- *
- * BUGS:
- * - sequence number wrapping
*/
#include "../ccid.h"
#include "../dccp.h"
#include "ccid2.h"
-static int ccid2_debug;
#ifdef CONFIG_IP_DCCP_CCID2_DEBUG
-#define ccid2_pr_debug(format, a...) \
- do { if (ccid2_debug) \
- printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
- } while (0)
-#else
-#define ccid2_pr_debug(format, a...)
-#endif
+static int ccid2_debug;
+#define ccid2_pr_debug(format, a...) DCCP_PR_DEBUG(ccid2_debug, format, ##a)
-#ifdef CONFIG_IP_DCCP_CCID2_DEBUG
static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
{
int len = 0;
pipe++;
/* packets are sent sequentially */
- BUG_ON(seqp->ccid2s_seq <= prev->ccid2s_seq);
+ BUG_ON(dccp_delta_seqno(seqp->ccid2s_seq,
+ prev->ccid2s_seq ) >= 0);
BUG_ON(time_before(seqp->ccid2s_sent,
prev->ccid2s_sent));
BUG_ON(len != hctx->ccid2hctx_seqbufc * CCID2_SEQBUF_LEN);
}
#else
-#define ccid2_hc_tx_check_sanity(hctx) do {} while (0)
+#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)
+static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx)
{
struct ccid2_seq *seqp;
int i;
return -ENOMEM;
/* allocate buffer and initialize linked list */
- seqp = kmalloc(sizeof(*seqp) * num, gfp);
+ seqp = kmalloc(CCID2_SEQBUF_LEN * sizeof(struct ccid2_seq), gfp_any());
if (seqp == NULL)
return -ENOMEM;
- for (i = 0; i < (num - 1); i++) {
+ for (i = 0; i < (CCID2_SEQBUF_LEN - 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];
+ 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->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;
+ 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 */
return 0;
}
-static int ccid2_hc_tx_send_packet(struct sock *sk,
- struct sk_buff *skb, int len)
+static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
{
- struct ccid2_hc_tx_sock *hctx;
+ struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
- 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:
+ if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd)
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)
+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);
+
/*
- * 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.
+ * 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 != 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;
+ 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;
- 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);
+ if (val == dp->dccps_l_ack_ratio)
+ return;
- BUG_ON(val < 1);
- hctx->ccid2hctx_cwnd = val;
+ 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)
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)
ccid2_start_rto_timer(sk);
/* adjust pipe, cwnd etc */
- ccid2_change_pipe(hctx, 0);
- hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1;
+ hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd / 2;
if (hctx->ccid2hctx_ssthresh < 2)
hctx->ccid2hctx_ssthresh = 2;
- ccid2_change_cwnd(hctx, 1);
+ hctx->ccid2hctx_cwnd = 1;
+ hctx->ccid2hctx_pipe = 0;
/* clear state about stuff we sent */
- hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh;
- hctx->ccid2hctx_ssacks = 0;
- hctx->ccid2hctx_acks = 0;
- hctx->ccid2hctx_sent = 0;
+ hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh;
+ hctx->ccid2hctx_packets_acked = 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);
jiffies + hctx->ccid2hctx_rto);
}
-static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, int len)
+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_pipe++;
- hctx->ccid2hctx_seqh->ccid2s_seq = seq;
+ 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) {
- int rc;
-
- ccid2_pr_debug("allocating more space in history\n");
- rc = ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_KERNEL);
- BUG_ON(rc); /* XXX what do we do? */
-
+ 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);
}
ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd,
hctx->ccid2hctx_pipe);
- hctx->ccid2hctx_sent++;
-
+ /*
+ * 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... */
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
- ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe);
- ccid2_pr_debug("Sent: seq=%llu\n", 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",
- seqp->ccid2s_seq, seqp->ccid2s_acked,
- seqp->ccid2s_sent);
+ (unsigned long long)seqp->ccid2s_seq,
+ seqp->ccid2s_acked, seqp->ccid2s_sent);
seqp = seqp->ccid2s_next;
}
} while (0);
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;
+ 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;
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;
- }
+ 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:
return -1;
out_invalid_option:
- BUG_ON(1); /* should never happen... options were previously parsed ! */
+ DCCP_BUG("Invalid option - this should not happen (previous parsing)!");
return -1;
}
}
static inline void ccid2_new_ack(struct sock *sk,
- struct ccid2_seq *seqp,
+ 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;
+ 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 */
/* first measurement */
if (hctx->ccid2hctx_srtt == -1) {
ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n",
- r, jiffies, seqp->ccid2s_seq);
+ r, jiffies,
+ (unsigned long long)seqp->ccid2s_seq);
ccid2_change_srtt(hctx, r);
hctx->ccid2hctx_rttvar = r >> 1;
} else {
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;
+ hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar,
+ hctx->ccid2hctx_rto, HZ, r);
}
/* we got a new ack, so re-start RTO timer */
{
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)
+ 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 ccid2_hc_tx_sock *hctx,
- struct ccid2_seq *seqp)
+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;
- ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd >> 1);
- hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd;
- if (hctx->ccid2hctx_ssthresh < 2)
- hctx->ccid2hctx_ssthresh = 2;
+ 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)
hctx->ccid2hctx_rpseq = seqno;
} else {
/* check if packet is consecutive */
- if ((hctx->ccid2hctx_rpseq + 1) == seqno)
- hctx->ccid2hctx_rpseq++;
+ 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 >=
- hctx->ccid2hctx_numdupack) {
+ if (hctx->ccid2hctx_rpdupack >= NUMDUPACK) {
hctx->ccid2hctx_rpdupack = -1; /* XXX lame */
hctx->ccid2hctx_rpseq = 0;
- ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio << 1);
+ ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio);
}
}
}
}
ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
- seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+ 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.
+ /*
+ * 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.
*/
- maxincr = dp->dccps_l_ack_ratio >> 1;
- maxincr++;
+ 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,
/* go through this ack vector */
while (veclen--) {
const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;
- u64 ackno_end_rl;
+ u64 ackno_end_rl = SUB48(ackno, rl);
- dccp_set_seqno(&ackno_end_rl, ackno - rl);
- ccid2_pr_debug("ackvec start:%llu end:%llu\n", ackno,
- ackno_end_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.
/* new packet received or marked */
if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED &&
!seqp->ccid2s_acked) {
- if (state ==
+ if (state ==
DCCP_ACKVEC_STATE_ECN_MARKED) {
- ccid2_congestion_event(hctx,
+ ccid2_congestion_event(sk,
seqp);
} else
ccid2_new_ack(sk, seqp,
seqp->ccid2s_acked = 1;
ccid2_pr_debug("Got ack for %llu\n",
- seqp->ccid2s_seq);
+ (unsigned long long)seqp->ccid2s_seq);
ccid2_hc_tx_dec_pipe(sk);
}
if (seqp == hctx->ccid2hctx_seqt) {
done = 1;
break;
}
- seqp = seqp->ccid2s_next;
+ seqp = seqp->ccid2s_prev;
}
if (done)
break;
-
- dccp_set_seqno(&ackno, ackno_end_rl - 1);
+ ackno = SUB48(ackno_end_rl, 1);
vector++;
}
if (done)
/* The state about what is acked should be correct now
* Check for NUMDUPACK
*/
- seqp = hctx->ccid2hctx_seqh->ccid2s_prev;
+ 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)
+ if (done == NUMDUPACK)
break;
}
if (seqp == hctx->ccid2hctx_seqt)
/* If there are at least 3 acknowledgements, anything unacknowledged
* below the last sequence number is considered lost
*/
- if (done == hctx->ccid2hctx_numdupack) {
+ 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",
- seqp->ccid2s_seq);
+ (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_congestion_event(sk, seqp);
ccid2_hc_tx_dec_pipe(sk);
}
if (seqp == hctx->ccid2hctx_seqt)
static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
{
- struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid);
+ 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;
- 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.
+ /*
+ * 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_ssthresh = ~0;
- hctx->ccid2hctx_numdupack = 3;
- hctx->ccid2hctx_seqbufc = 0;
+ 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, CCID2_SEQBUF_LEN, GFP_ATOMIC) != 0)
+ if (ccid2_hc_tx_alloc_seq(hctx))
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_rtotimer.function = &ccid2_hc_tx_rto_expire;
- hctx->ccid2hctx_rtotimer.data = (unsigned long)sk;
- init_timer(&hctx->ccid2hctx_rtotimer);
+ 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);
+ struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
int i;
ccid2_hc_tx_kill_rto_timer(sk);
static struct ccid_operations ccid2 = {
.ccid_id = DCCPC_CCID2,
- .ccid_name = "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_rx_packet_recv = ccid2_hc_rx_packet_recv,
};
-module_param(ccid2_debug, int, 0444);
+#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)
{
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff