dtrace_sctp —
a
DTrace provider for tracing events related to the
sctp(4) protocol
sctp:cwnd::init(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:cwnd::ack(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:cwnd::rttvar(
uint64_t,
uint64_t,
uint64_t,
uint64_t,
uint64_t);
sctp:cwnd::rttstep(
uint64_t,
uint64_t,
uint64_t,
uint64_t,
uint64_t);
sctp:cwnd::fr(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:cwnd::to(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:cwnd::bl(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:cwnd::ecn(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:cwnd::pd(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:rwnd:assoc:val(
uint32_t,
uint32_t,
int,
int);
sctp:flightsize:net:val(
uint32_t,
uint32_t,
uintptr_t,
int,
int);
sctp:flightsize:assoc:val(
uint32_t,
uint32_t,
int,
int);
sctp:::receive(
pktinfo_t
*,
csinfo_t
*,
ipinfo_t
*,
sctpsinfo_t
*,
sctpinfo_t
*);
sctp:::send(
pktinfo_t
*,
csinfo_t
*,
ipinfo_t
*,
sctpsinfo_t
*,
sctpinfo_t
*);
sctp:::state-change(
void
*,
csinfo_t
*,
void *,
sctpsinfo_t *,
void *,
sctplsinfo_t *);
The DTrace
sctp provider allows users to trace
events in the
sctp(4) protocol implementation.
This provider is similar to the
dtrace_ip(4) and
dtrace_udp(4) providers, but additionally
contains probes corresponding to protocol events at a level higher than packet
reception and transmission.
The
sctp:cwnd::() probes track changes in the
congestion window on a netp. The
sctp:rwnd::()
probes track changes in the receiver window for an assoc. The
sctp:flightsize:net:val() probe tracks changes in
the flight size on a net or assoc and the
sctp:flightsize:assoc:val() probe provides the
total flight version.
The arguments of all
sctp probes except for
sctp:cwnd::rtt*() and
sctp::assoc:val() are the Vtag for this end, the
port number of the local side, the pointer to
struct sctp_nets *changing, the old value
of the cwnd, and the new value of the cwnd.
The arguments of
sctp:::val() are similar to the
above except the fourth argument is the up/down amount.
The
sctp:cwnd::rtt*() probe arguments are a bitmap
of
Vtag << 32 |
localport << 16 |
remoteport, a bitmap of
obw |
nbw, a bitmap of
bwrtt |
newrtt,
flight, and a bitmap of
(cwnd << 32) |
point << 16 |
retval(0/1).
The
sctp:cwnd::init() probe fires when a
remotely-initiated active SCTP open succeeds. At this point the new connection
is in the ESTABLISHED state, and the probe arguments expose the headers
associated with the final ACK of the four-way handshake.
The
sctp:::send() and
sctp:::receive() probes fire when the host sends
or receives an SCTP packet, respectively. As with the
dtrace_udp(4) provider,
sctp probes fire only for packets sent by or to
the local host; forwarded packets are handled in the IP layer and are only
visible to the
dtrace_ip(4) provider.
The
sctp:::state-change() probe fires upon local
SCTP association state transitions. Its first, third and fifth arguments are
currently always
NULL. Its last argument
describes the from-state in the transition, and the to-state can be obtained
from
args[3]->sctps_state.
- /usr/lib/dtrace/sctp.d
- DTrace type and translator definitions for the
sctp provider.
A script that logs SCTP packets in real time:
#pragma D option quiet
#pragma D option switchrate=10hz
dtrace:::BEGIN
{
printf(" %3s %15s:%-5s %15s:%-5s0, "CPU",
"LADDR", "LPORT", "RADDR", "RPORT");
}
sctp:::send
{
printf(" %3d %16s:%-5d -> %16s:%-5d0, cpu,
args[2]->ip_saddr, args[4]->sctp_sport,
args[2]->ip_daddr, args[4]->sctp_dport);
}
sctp:::receive
{
printf(" %3d %16s:%-5d <- %16s:%-5d0, cpu,
args[2]->ip_daddr, args[4]->sctp_dport,
args[2]->ip_saddr, args[4]->sctp_sport);
}
A script that logs SCTP association state changes as they occur:
#pragma D option quiet
#pragma D option switchrate=10
int last[int];
dtrace:::BEGIN
{
printf(" %3s %12s %-25s %-25s0,
"CPU", "DELTA(us)", "OLD", "NEW");
}
sctp:::state-change
/ last[args[1]->cs_cid] /
{
this->elapsed = (timestamp - last[args[1]->cs_cid]) / 1000;
printf(" %3d %12d %-25s -> %-25s0, cpu, this->elapsed,
sctp_state_string[args[5]->sctps_state],
sctp_state_string[args[3]->sctps_state]);
last[args[1]->cs_cid] = timestamp;
}
sctp:::state-change
/ last[args[1]->cs_cid] == 0 /
{
printf(" %3d %12s %-25s -> %-25s0, cpu, "-",
sctp_state_string[args[5]->sctps_state],
sctp_state_string[args[3]->sctps_state]);
last[args[1]->cs_cid] = timestamp;
}
The
sctp:::send(),
sctp:::receive(), and
sctp:::state-change() probes are compatible with
the
sctp provider in Solaris. All other probes
are only available in FreeBSD.
dtrace(1),
dtrace_ip(4),
dtrace_udp(4),
dtrace_udplite(4),
sctp(4),
SDT(9)
This manual page was written by
Devin Teske
<
[email protected]>.