static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2) { u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, s2 = DCCP_SKB_CB(skb)->dccpd_seq; if (likely(dccp_delta_seqno(s1, s2) > 0)) { /* S1 < S2 */ h->loss_count = 2; tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n2); return; } /* S0 < S2 < S1 */ if (dccp_loss_free(s0, s2, n2)) { u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; if (dccp_loss_free(s2, s1, n1)) { /* hole is filled: S0, S2, and S1 are consecutive */ h->loss_count = 0; h->loss_start = tfrc_rx_hist_index(h, 1); } else /* gap between S2 and S1: just update loss_prev */ tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n2); } else { /* gap between S0 and S2 */ /* * Reorder history to insert S2 between S0 and S1 */ tfrc_rx_hist_swap(h, 0, 3); h->loss_start = tfrc_rx_hist_index(h, 3); tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n2); h->loss_count = 2; } }
/* recycle RX history records to continue loss detection if necessary */ static void __three_after_loss(struct tfrc_rx_hist *h) { /* * At this stage we know already that there is a gap between S0 and S1 * (since S0 was the highest sequence number received before detecting * the loss). To recycle the loss record, it is thus only necessary to * check for other possible gaps between S1/S2 and between S2/S3. */ u64 s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, s3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_seqno; u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp, n3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_ndp; if (dccp_loss_free(s1, s2, n2)) { if (dccp_loss_free(s2, s3, n3)) { /* no gap between S2 and S3: entire hole is filled */ h->loss_start = tfrc_rx_hist_index(h, 3); h->loss_count = 0; } else { /* gap between S2 and S3 */ h->loss_start = tfrc_rx_hist_index(h, 2); h->loss_count = 1; } } else { /* gap between S1 and S2 */ h->loss_start = tfrc_rx_hist_index(h, 1); h->loss_count = 2; } }
static void __three_after_loss(struct tfrc_rx_hist *h) { /* */ u64 s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, s3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_seqno; u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp, n3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_ndp; if (dccp_loss_free(s1, s2, n2)) { if (dccp_loss_free(s2, s3, n3)) { /* */ h->loss_start = tfrc_rx_hist_index(h, 3); h->loss_count = 0; } else { /* */ h->loss_start = tfrc_rx_hist_index(h, 2); h->loss_count = 1; } } else { /* */ h->loss_start = tfrc_rx_hist_index(h, 1); h->loss_count = 2; } }
static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2) { u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, s2 = DCCP_SKB_CB(skb)->dccpd_seq; if (likely(dccp_delta_seqno(s1, s2) > 0)) { /* */ h->loss_count = 2; tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n2); return; } /* */ if (dccp_loss_free(s0, s2, n2)) { u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; if (dccp_loss_free(s2, s1, n1)) { /* */ h->loss_count = 0; h->loss_start = tfrc_rx_hist_index(h, 1); } else /* */ tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n2); } else { /* */ /* */ tfrc_rx_hist_swap(h, 0, 3); h->loss_start = tfrc_rx_hist_index(h, 3); tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n2); h->loss_count = 2; } }
/* * Private helper functions for loss detection. * * In the descriptions, `Si' refers to the sequence number of entry number i, * whose NDP count is `Ni' (lower case is used for variables). * Note: All __xxx_loss functions expect that a test against duplicates has been * performed already: the seqno of the skb must not be less than the seqno * of loss_prev; and it must not equal that of any valid history entry. */ static void __do_track_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u64 n1) { u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, s1 = DCCP_SKB_CB(skb)->dccpd_seq; if (!dccp_loss_free(s0, s1, n1)) { /* gap between S0 and S1 */ h->loss_count = 1; tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n1); } }
/* return 1 if a new loss event has been identified */ static int __two_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n3) { u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, s3 = DCCP_SKB_CB(skb)->dccpd_seq; if (likely(dccp_delta_seqno(s2, s3) > 0)) { /* S2 < S3 */ h->loss_count = 3; tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 3), skb, n3); return 1; } /* S3 < S2 */ if (dccp_delta_seqno(s1, s3) > 0) { /* S1 < S3 < S2 */ /* * Reorder history to insert S3 between S1 and S2 */ tfrc_rx_hist_swap(h, 2, 3); tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n3); h->loss_count = 3; return 1; } /* S0 < S3 < S1 */ if (dccp_loss_free(s0, s3, n3)) { u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; if (dccp_loss_free(s3, s1, n1)) { /* hole between S0 and S1 filled by S3 */ u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp; if (dccp_loss_free(s1, s2, n2)) { /* entire hole filled by S0, S3, S1, S2 */ h->loss_start = tfrc_rx_hist_index(h, 2); h->loss_count = 0; } else { /* gap remains between S1 and S2 */ h->loss_start = tfrc_rx_hist_index(h, 1); h->loss_count = 1; } } else /* gap exists between S3 and S1, loss_count stays at 2 */ tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n3); return 0; } /* * The remaining case: S0 < S3 < S1 < S2; gap between S0 and S3 * Reorder history to insert S3 between S0 and S1. */ tfrc_rx_hist_swap(h, 0, 3); h->loss_start = tfrc_rx_hist_index(h, 3); tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n3); h->loss_count = 3; return 1; }
static int __two_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n3) { u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, s3 = DCCP_SKB_CB(skb)->dccpd_seq; if (likely(dccp_delta_seqno(s2, s3) > 0)) { /* */ h->loss_count = 3; tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 3), skb, n3); return 1; } /* */ if (dccp_delta_seqno(s1, s3) > 0) { /* */ /* */ tfrc_rx_hist_swap(h, 2, 3); tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n3); h->loss_count = 3; return 1; } /* */ if (dccp_loss_free(s0, s3, n3)) { u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; if (dccp_loss_free(s3, s1, n1)) { /* */ u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp; if (dccp_loss_free(s1, s2, n2)) { /* */ h->loss_start = tfrc_rx_hist_index(h, 2); h->loss_count = 0; } else { /* */ h->loss_start = tfrc_rx_hist_index(h, 1); h->loss_count = 1; } } else /* */ tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n3); return 0; } /* */ tfrc_rx_hist_swap(h, 0, 3); h->loss_start = tfrc_rx_hist_index(h, 3); tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n3); h->loss_count = 3; return 1; }