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:

             uintptr_t pkt_addr  Always set to 0.

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

             uintptr_t cs_addr  Always set to 0.

             uint64_t cs_cid    A pointer to the struct inpcb for this packet, or NULL.

             pid_t cs_pid       Always set to 0.

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

             uint8_t ip_ver       IP version of the packet, 4 for IPv4 packets and 6 for IPv6 packets.

             uint32_t ip_plength  IP payload size.  This does not include the size of  the  IP  header  or  IPv6
                                  option headers.

             string ip_saddr      IP source address.

             string ip_daddr      IP destination address.

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

             uintptr_t udplites_addr  Pointer to the struct inpcb containing the IP  state  for  the  associated
                                      socket.

             uint16_t udplites_lport  Local UDP-Lite port.

             uint16_t udplites_rport  Remote UDP-Lite port.

             string udplites_laddr    Local IPv4 or IPv6 address.

             string udplites_raddr    Remote IPv4 or IPv6 address.

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

             uint16_t udplite_sport          Source UDP-Lite port.

             uint16_t udplite_dport          Destination UDP-Lite port.

             uint16_t udplite_coverage       Checksum coverage of the UDP-Lite header, in bytes, or 0  for  full
                                             coverage.

             uint16_t udplite_checksum       A  checksum of the UDP-Lite header and payload, or 0 if no checksum
                                             was calculated.

             struct udplitehdr *udplite_hdr  A pointer to the raw UDP-Lite header.

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>.

Debian                                           August 1, 2018                                DTRACE_UDPLITE(4)