diff options
| author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2007-03-20 21:23:18 +0300 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 09:27:00 +0400 |
| commit | 4712a792ee661921374c163eb6a4d06e33fd305f (patch) | |
| tree | 0c5ecf7973a195bff36101904417bb7b90fd18aa /net/dccp/dccp.h | |
| parent | 0c150efb280986db7958cf2a559b91d826241e59 (diff) | |
| download | linux-4712a792ee661921374c163eb6a4d06e33fd305f.tar.xz | |
[DCCP]: Provide function for RTT sampling
A recurring problem, in particular in the CCID code, is that RTT samples
from packets with timestamp echo and elapsed time options need to be taken.
This service is provided via a new function dccp_sample_rtt in this patch.
Furthermore, to protect against `insane' RTT samples, the sampled value
is bounded between 100 microseconds and 4 seconds - for which u32 is sufficient.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp/dccp.h')
| -rw-r--r-- | net/dccp/dccp.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 292f18ef4f61..d8ad27bfe01a 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -71,11 +71,15 @@ extern void dccp_time_wait(struct sock *sk, int state, int timeo); /* RFC 1122, 4.2.3.1 initial RTO value */ #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ)) +#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */ + +/* bounds for sampled RTT values from packet exchanges (in usec) */ +#define DCCP_SANE_RTT_MIN 100 +#define DCCP_SANE_RTT_MAX (4 * USEC_PER_SEC) + /* Maximal interval between probes for local resources. */ #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U)) -#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */ - /* sysctl variables for DCCP */ extern int sysctl_dccp_request_retries; extern int sysctl_dccp_retries1; @@ -292,6 +296,8 @@ extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); extern void dccp_send_close(struct sock *sk, const int active); extern int dccp_invalid_packet(struct sk_buff *skb); +extern u32 dccp_sample_rtt(struct sock *sk, struct timeval *t_recv, + struct timeval *t_history); static inline int dccp_bad_service_code(const struct sock *sk, const __be32 service) |