Skip to content
Tom Barbette edited this page May 7, 2020 · 3 revisions

ToIPSummaryDump Element Documentation

NAME

ToIPSummaryDump — Click element; writes packet summary information to an ASCII file

SYNOPSIS

ToIPSummaryDump(FILENAME [, keywords])

Ports: 1 input, at most 1 output
Drivers: userlevel

DESCRIPTION

Writes summary information about incoming packets to FILENAME in a simple ASCII format---each line corresponds to a packet. The FIELDS keyword argument determines what information is written. Writes to standard output if FILENAME is a single dash `-'. The BINARY keyword argument writes a packed binary format to save space.

ToIPSummaryDump uses packets' extra-length and extra-packet-count annotations.

ToIPSummaryDump can optionally be used as a filter: it pushes received packets to its output if that output exists.

Keyword arguments are:

  • FIELDS — Space-separated list of field names. Each line of the summary dump will contain those fields. Valid field names, with examples, are:

         timestamp    Packet timestamp: '996033261.451094' (either
                      microsecond or nanosecond precision, depending
                      on how Click was compiled)
         ts_sec       Seconds portion of timestamp: '996033261'
         ts_usec      Microseconds portion of timestamp: '451094'
         ts_usec1     Packet timestamp in microseconds
                      (ts_sec*1e6 + ts_usec): '996033261451094'
         ip_src       IP source address: '192.150.187.37'
         ip_dst       IP destination address: '192.168.1.100'
         ip_frag      IP fragment: 'F' (1st frag), 'f' (2nd or
                      later frag), '!' (nonfrag with DF), or
                      '.' (normal nonfrag)
         ip_fragoff   IP fragmentation offset: '0', '0+', '0!'
                      ('+' adds MF, '!' adds DF; offset in bytes)
         ip_len       IP length: '132'
         ip_proto     IP protocol: '10', or 'I' for ICMP, 'T' for
                      TCP, 'U' for UDP
         ip_hl        IP header length in bytes: '20'
         ip_id        IP ID: '48759'
         ip_tos       IP type of service: '29'
         ip_dscp      IP Differentiated Services code point: '29'
         ip_ecn       IP ECN capability: 'no', 'ect1', 'ect2', 'ce'
         ip_ttl       IP time-to-live: '254'
         ip_sum       IP checksum: '43812'
         ip_opt       IP options (see below)
         sport        TCP/UDP source port: '22'
         dport        TCP/UDP destination port: '2943'
         tcp_seq      TCP sequence number: '93167339'
         tcp_ack      TCP acknowledgement number: '93178192'
         tcp_off      TCP offset in bytes: '20'
         tcp_flags    TCP flags: 'SA', '.'
         tcp_opt      TCP options (see below)
         tcp_ntopt    TCP options except NOP, EOL and timestamp
                      (see below)
         tcp_sack     TCP SACK options (see below)
         tcp_window   TCP receive window: '480'
         tcp_urp      TCP urgent pointer: '0'
         udp_len      UDP length: '34'
         icmp_type    ICMP type: '0'
         icmp_code    ICMP code: '2'
         icmp_type_name  ICMP type, named if available: 'echo',
                      '200'
         icmp_code_name  ICMP code, named if available:
                      'sourcequench', '0'
         icmp_flowid  ICMP flow identifier, in network order: '256'
         icmp_seq     ICMP sequence number, in network order: '0'
         icmp_nextmtu  ICMP next-hop MTU (unreach.needfrag only):
                      '256'
         payload      Payload (not including IP/TCP/UDP headers,
                      for this fragment), in a string
         payload_len  Payload length: '34'
         payload_md5  Payload MD5 checksum (in ASCII output,
                      expressed using 22 chars from [A-Za-z0-9_@])
         payload_md5_hex  Payload MD5 checksum (in ASCII output,
                      expressed using 32 hexadecimal digits)
         ip_capture_len  Portion of IP length that contains
                      actual packet data (as opposed to the extra
                      length annotation): '34'
         count        Number of packets: '1'
         direction    Link number (PAINT_ANNO): '2', or '>'/'L'
                      for paint 0, '<'/'R'/'X' for paint 1
         link, paint  Like 'direction', but always numeric
         aggregate    Aggregate number (AGGREGATE_ANNO): '973'
         first_timestamp   Packet "first timestamp" (FIRST_
                      TIMESTAMP_ANNO): '996033261.451094'
         eth_src      Ethernet source: '00-0A-95-A6-D9-BC'
         eth_dst      Ethernet source: '00-0A-95-A6-D9-BC'
         wire_len     Packet wire length: '54'
         thread       Current thread id: '0'
    

    If a field does not apply to a particular packet -- for example, 'sport' on an ICMP packet -- ToIPSummaryDump prints a single dash for that value.

    Default FIELDS is 'ip_src ip_dst'. You may also use spaces instead of underscores, in which case you must quote field names that contain a space -- for example, 'ip_src ip_dst "tcp seq"'.

  • HEADER — Boolean. If true, then print any '!' header lines at the beginning of the dump to describe the dump format. Default is true.

  • VERBOSE — Boolean. If true, then print out a couple comments at the beginning of the dump describing the hostname and starting time, in addition to the '!data' line describing the dumped fields. Ignored if HEADER is false. Default is false.

  • BANNER — String. If supplied, prints a '!creator "BANNER"' comment at the beginning of the dump. Ignored if HEADER is false.

  • BINARY — Boolean. If true, then output packet records in a binary format (explained below). Defaults to false.

  • MULTIPACKET — Boolean. If true, and the FIELDS option doesn't contain 'count', then generate multiple summary entries for packets with nonzero extra-packets annotations. For example, if MULTIPACKET is true, and a packet has extra-packets annotation 1, then ToIPSummaryDump will generate 2 lines for that packet in the dump. False by default.

  • BAD_PACKETS — Boolean. If true, then print '!bad MESSAGE' lines for packets with bad IP, TCP, or UDP headers, as well as normal output. The '!bad' line immediately precedes the corresponding packet. Output will contain dashes '-' in place of data from bad headers. Default is false.

  • CAREFUL_TRUNC — Boolean. If true, then print '!bad truncated IP length' lines for packets whose data plus extra length annotation is less than their IP length. Tcpdump prints 'truncated-ip - N bytes missing' for such packets. Actual packet output immediately follows the '!bad' line. Default is true.

  • EXTRA_LENGTH — Boolean. If false, then ignore extra length annotations. Defaults to true.

EXAMPLES

Here are a couple lines from the start of a sample verbose dump.

  !IPSummaryDump 1.3
  !creator "aciri-ipsumdump -i wvlan0"
  !host no.lcdf.org
  !runtime 996022410.322317 (Tue Jul 24 17:53:30 2001)
  !data ip_src ip_dst
  63.250.213.167 192.150.187.106
  63.250.213.167 192.150.187.106

The end of the dump may contain a comment '!drops N', meaning that N packets were dropped before they could be entered into the dump.

A '!flowid' comment can specify source and destination addresses and ports for packets that otherwise don't have one. Its arguments are '!flowid SRC SPORT DST DPORT [PROTO]'.

Any packet line may contain fewer fields than specified in the '!data' line, down to one field. Missing fields are treated as '-'.

NOTES

The 'len' and 'payload_len' fields use the extra length annotation. The 'count' field uses the extra packets annotation.

The characters corresponding to TCP flags are as follows:

   Flag name  Character  Value
   ---------  ---------  -----
   FIN        F          0x01
   SYN        S          0x02
   RST        R          0x04
   PSH        P          0x08
   ACK        A          0x10
   URG        U          0x20
   ECE        E          0x40
   CWR        C          0x80
   NS         N          0x100

The 'W' character is also acceptable for CWR. Old IP summary dumps might contain an unsigned integer, representing the flags byte, or might use 'X' and 'Y' for ECE and CWR, respectively.

Verson 1.0 of the IPSummaryDump file format expressed fragment offsets in 8-byte units, not bytes. Fields in old dumps were sometimes quoted and contained spaces instead of underscores. In Version 1.2 files payload MD5 checksums were sometimes incorrect.

IP OPTIONS

Single IP option fields have the following representations.

    EOL, NOP        Not written, but FromIPSummaryDump
                    understands 'eol' and 'nop'
 
    RR              'rr{10.0.0.1,20.0.0.2}+5' (addresses
                    inside the braces come before the
                    pointer; '+5' means there is space for
                    5 more addresses after the pointer)
 
    SSRR, LSRR      'ssrr{1.0.0.1,1.0.0.2^1.0.0.3}'
                    ('^' indicates the pointer)
 
    TS              'ts{1,10000,!45}+2++3' (timestamps only
                    [type 0]; timestamp values 1, 10000,
                    and 45 [but 45 has the "nonstandard
                    timestamp" bit set]; the option has
                    room for 2 more timestamps; the
                    overflow counter is set to 3)
 
                    'ts.ip{1.0.0.1=1,1.0.0.2=2}+5'
                    (timestamps with IP addresses [type 1])
 
                    'ts.preip{1.0.0.1=1^1.0.0.2,1.0.0.3}'
                    (prespecified IP addresses [type 3];
                    the caret is the pointer)
 
    Other options   '98' (option 98, no data),
                    '99=0:5:10' (option with data, data
                    octets separated by colons)

Multiple options are separated by semicolons. (No single option will ever contain a semicolon.) Any invalid option causes the entire field to be replaced by a single question mark '?'. A period '.' is used for packets with no options (except possibly EOL and NOP).

TCP OPTIONS

Single TCP option fields have the following representations.

    EOL, NOP        Not written, but FromIPSummaryDump
                    understands 'eol' and 'nop'
    MSS             'mss1400'
    Window scale    'wscale10'
    SACK permitted  'sackok'
    SACK            'sack95-98'; each SACK block
                    is listed separately
    Timestamp       'ts669063908:38382731'
    Other options   '98' (option 98, no data),
                    '99=0:5:10' (option with data, data
                    octets separated by colons)

Multiple options are separated by semicolons. (No single option will ever contain a semicolon.) Any invalid option causes the entire field to be replaced by a single question mark '?'. A period '.' is used for packets with no options (except possibly EOL and NOP).

BINARY FORMAT

Binary IPSummaryDump files begin with several ASCII lines, just like regular files. The line '!binary' indicates that the rest of the file, starting immediately after the newline, consists of binary records. Each record looks like this:

   +---------------+------------...
   |X|record length|    data
   +---------------+------------...
    <---4 bytes--->

The initial word of data contains the record length in bytes. (All numbers in the file are stored in network byte order.) The record length includes the initial word itself, so the minimum valid record length is 4. The high-order bit 'X' is the metadata indicator. It is zero for regular packets and one for metadata lines.

Regular packet records have binary fields stored in the order indicated by the '!data' line, as follows:

   Field Name    Length  Description
   timestamp        8    timestamp sec + usec
   utimestamp       8    timestamp sec + usec
   ntimestamp       8    timestamp sec + nsec
   ts_sec, ts_usec  4    timestamp sec/usec
   ts_usec1         8    timestamp in usec
   ip_src           4    IP source address
   ip_dst           4    IP destination address
   sport            2    source port
   dport            2    destination port
   ip_len           4    IP length field
   ip_proto         1    IP protocol
   ip_id            2    IP ID
   ip_tos           1    IP TOS
   ip_ttl           1    IP TTL
   ip_frag          1    fragment descriptor
                         ('F', 'f', or '.')
   ip_fragoff       2    IP fragment offset field
   ip_opt           ?    IP options
   tcp_seq          4    TCP sequence number
   tcp_ack          4    TCP ack number
   tcp_flags        1    TCP flags
   tcp_opt          ?    TCP options
   tcp_ntopt        ?    TCP non-timestamp options
   tcp_sack         ?    TCP SACK options
   udp_len          4    UDP length
   payload_len      4    payload length
   payload_md5     16    payload MD5 checksum
   payload_md5_hex 16    payload MD5 checksum
   ip_capture_len   4    IP capture length
   count            4    packet count
   first_timestamp  8    timestamp sec + usec
   eth_src          6    Ethernet source address
   eth_dst          6    Ethernet destination address

Each field is Length bytes long. Variable-length fields have Length '?' in the table; in a packet record, these fields consist of a single length byte, followed by that many bytes of data.

The data stored in a metadata record is just an ASCII string, ending with newline, same as in a regular ASCII IPSummaryDump file. '!bad' records, for example, are stored this way.

ELEMENT HANDLERS

  • flush (write-only) — Flush all internal buffers to disk.

SEE ALSO

FromIPSummaryDump, FromDump, ToDump

Generated by click-elem2man from ../elements/analysis/toipsumdump.hh:11 on 2020/05/07.

Clone this wiki locally