NAME

dtrace_udplite — a DTrace provider for tracing events related to the UDP-Lite protocol

SYNOPSIS

udplite:::receive(pktinfo_t *, csinfo_t *, ipinfo_t *, udplitesinfo_t *, udpliteinfo_t *);

udplite:::send(pktinfo_t *, csinfo_t *, ipinfo_t *, udplitesinfo_t *, udpliteinfo_t *);

DESCRIPTION

The DTrace udplite provider allows users to trace events in the udplite(4) protocol implementation. The udplite:::send() probe fires whenever the kernel prepares to transmit a UDP-Lite packet, and the udplite:::receive() probe fires whenever the kernel receives a UDP-Lite packet, unless the UDP-Lite header is incomplete, the destination port is 0, the length field is invalid, or the checksum is wrong. The arguments to these probes can be used to obtain detailed information about the IP and UDP-Lite headers of the corresponding packet.

ARGUMENTS

The pktinfo_t argument is currently unimplemented and is included for compatibility with other implementations of this provider. Its fields are:

The csinfo_t argument is currently unimplemented and is included for compatibility with other implementations of this provider. Its fields are:

The ipinfo_t argument contains IP fields common to both IPv4 and IPv6 packets. Its fields are:

The udplitesinfo_t argument contains the state of the UDP-Lite connection associated with the packet. Its fields are:

The udpliteinfo_t argument is the raw UDP-Lite header of the packet, with all fields in host order. Its fields are:

FILES

/usr/lib/dtrace/udplite.d

DTrace type and translator definitions for the udplite provider.

EXAMPLES

The following script counts transmitted packets by destination port.

udplite:::send
{
        @num[args[4]->udplite_dport] = count();
}

This script will print some details of each UDP-Lite packet as it is sent or received by the kernel:

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

dtrace:::BEGIN
{
        printf(" %10s %36s    %-36s %6s\n", "DELTA(us)", "SOURCE",
            "DEST", "COV");
        last = timestamp;
}

udplite:::send
{
        this->elapsed = (timestamp - last) / 1000;
        self->dest = strjoin(strjoin(args[2]->ip_daddr, ":"),
             lltostr(args[4]->udplite_dport));
        printf(" %10d %30s:%-5d -> %-36s %6d\n", this->elapsed,
            args[2]->ip_saddr, args[4]->udplite_sport,
            self->dest, args[4]->udplite_coverage);
        last = timestamp;
}

udplite:::receive
{
        this->elapsed = (timestamp - last) / 1000;
        self->dest = strjoin(strjoin(args[2]->ip_saddr, ":"),
             lltostr(args[4]->udplite_sport));
        printf(" %10d %30s:%-5d <- %-36s %6d\n", this->elapsed,
            args[2]->ip_daddr, args[4]->udplite_dport,
            self->dest, args[4]->udplite_coverage);
        last = timestamp;
}

SEE ALSO

dtrace(1), dtrace_ip(4), dtrace_sctp(4), dtrace_tcp(4), dtrace_udp(4), udplite(4), SDT(9)

HISTORY

The udplite provider first appeared in FreeBSD 12.0.

AUTHORS

This manual page was written by Mark Johnston <markj@FreeBSD.org> and
Michael Tuexen <tuexen@FreeBSD.org>.