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| author | Eric Dumazet <edumazet@google.com> | 2018-06-22 06:44:15 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-06-23 10:46:44 +0900 |
| commit | 0ce4e70ff00662ad7490e545ba0cd8c1fa179fca (patch) | |
| tree | 4959b26fee49e3465efd6d73539b74d459340870 /net/dccp | |
| parent | 74174fe5634ffbf645a7ca5a261571f700b2f332 (diff) | |
| download | lwn-0ce4e70ff00662ad7490e545ba0cd8c1fa179fca.tar.gz lwn-0ce4e70ff00662ad7490e545ba0cd8c1fa179fca.zip | |
net: dccp: switch rx_tstamp_last_feedback to monotonic clock
To compute delays, better not use time of the day which can
be changed by admins or malicious programs.
Also change ccid3_first_li() to use s64 type for delta variable
to avoid potential overflows.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: dccp@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index d57a2be1e2e0..12877a1514e7 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -600,7 +600,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk, { struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); struct dccp_sock *dp = dccp_sk(sk); - ktime_t now = ktime_get_real(); + ktime_t now = ktime_get(); s64 delta = 0; switch (fbtype) { @@ -632,7 +632,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk, return; } - ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, + ccid3_pr_debug("Interval %lldusec, X_recv=%u, 1/p=%u\n", delta, hc->rx_x_recv, hc->rx_pinv); hc->rx_tstamp_last_feedback = now; @@ -679,7 +679,8 @@ static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) static u32 ccid3_first_li(struct sock *sk) { struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); - u32 x_recv, p, delta; + u32 x_recv, p; + s64 delta; u64 fval; if (hc->rx_rtt == 0) { @@ -687,7 +688,9 @@ static u32 ccid3_first_li(struct sock *sk) hc->rx_rtt = DCCP_FALLBACK_RTT; } - delta = ktime_to_us(net_timedelta(hc->rx_tstamp_last_feedback)); + delta = ktime_us_delta(ktime_get(), hc->rx_tstamp_last_feedback); + if (delta <= 0) + delta = 1; x_recv = scaled_div32(hc->rx_bytes_recv, delta); if (x_recv == 0) { /* would also trigger divide-by-zero */ DCCP_WARN("X_recv==0\n"); |