diff options
Diffstat (limited to 'net/dccp/ccids/lib/packet_history.c')
| -rw-r--r-- | net/dccp/ccids/lib/packet_history.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c index 13973606471..4805de99656 100644 --- a/net/dccp/ccids/lib/packet_history.c +++ b/net/dccp/ccids/lib/packet_history.c @@ -39,12 +39,24 @@ #include <linux/string.h> #include "packet_history.h" +/** + * tfrc_tx_hist_entry - Simple singly-linked TX history list + * @next: next oldest entry (LIFO order) + * @seqno: sequence number of this entry + * @stamp: send time of packet with sequence number @seqno + */ +struct tfrc_tx_hist_entry { + struct tfrc_tx_hist_entry *next; + u64 seqno; + ktime_t stamp; +}; + /* * Transmitter History Routines */ static struct kmem_cache *tfrc_tx_hist; -struct tfrc_tx_hist_entry * +static struct tfrc_tx_hist_entry * tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno) { while (head != NULL && head->seqno != seqno) @@ -52,7 +64,6 @@ struct tfrc_tx_hist_entry * return head; } -EXPORT_SYMBOL_GPL(tfrc_tx_hist_find_entry); int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno) { @@ -83,6 +94,24 @@ void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp) } EXPORT_SYMBOL_GPL(tfrc_tx_hist_purge); +u32 tfrc_tx_hist_rtt(struct tfrc_tx_hist_entry *head, const u64 seqno, + const ktime_t now) +{ + u32 rtt = 0; + struct tfrc_tx_hist_entry *packet = tfrc_tx_hist_find_entry(head, seqno); + + if (packet != NULL) { + rtt = ktime_us_delta(now, packet->stamp); + /* + * Garbage-collect older (irrelevant) entries: + */ + tfrc_tx_hist_purge(&packet->next); + } + + return rtt; +} +EXPORT_SYMBOL_GPL(tfrc_tx_hist_rtt); + /* * Receiver History Routines */ |