sctpstate.d Tracing State Changes

This following DTrace script demonstrates the capability to trace SCTP state changes:

#!/usr/sbin/dtrace -s

#pragma D option quiet
#pragma D option switchrate=10

int last[int];

dtrace:::BEGIN
{
        printf(" %3s %12s  %-20s    %-20s\n", "CPU", "DELTA(us)", "OLD", "NEW");
        last = timestamp;
}

sctp:::state-change
/ last[args[1]->cs_cid] /
{
        this->elapsed = (timestamp - last[args[1]->cs_cid]) / 1000;
        printf(" %3d %12d  %-20s -> %-20s\n", 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  %-20s -> %-20s\n", cpu, "-",
            sctp_state_string[args[5]->sctps_state],
            sctp_state_string[args[3]->sctps_state]);
        last[args[1]->cs_cid] = timestamp;
}

The fields printed are as follows:

Field	Description
CPU	CPU ID of the event
DELTA	Time since previous event for that connection, microseconds
OLD	Old SCTP state
NEW	New SCTP state