`igmp` Provider

The igmp provider provides probes for tracing the IGMP protocol.

This provider is under development and is not yet available

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Probes

The igmp probes are described in the table below.

`igmp` Probes

Probe	Description
`send`	Probe that fires whenever IGMP sends a message.
`receive`	Probe that fires whenever IGMP receives a message.

Arguments

The argument types for the igmp probes are listed in the table below. The arguments are described in the following section.

`igmp` Probe Arguments

Probe	`args[0]`	`args[1]`	`args[2]`	`args[3]`	`args[4]`
`send`	`pktinfo_t *`	`csinfo_t *`	`ipinfo_t *`	`ifinfo_t *`	`igmpinfo_t *`
`receive`	`pktinfo_t *`	`csinfo_t *`	`ipinfo_t *`	`ifinfo_t *`	`igmpinfo_t *`

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`pktinfo_t` structure

The pktinfo_t structure is where packet ID info can be made available for deeper analysis if packet IDs become supported by the kernel in the future.
The pkt_addr member is currently always NULL.

typedef struct pktinfo {
        uintptr_t pkt_addr;             /* currently always NULL */
} pktinfo_t;

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`csinfo_t` structure

The csinfo_t structure is where connection state info is made available. For IGMP, the connection ID and process ID fields are unused since IGMP events are not tied to particular processess/connections.

typedef struct csinfo {
        uintptr_t cs_addr;
	uint64_t cs_cid;
	pid_t cs_pid;
	zoneid_t cs_zoneid;
 } csinfo_t;

`csinfo_t` Members

`cs_addr`	Address of translated ill_t *.
`cs_cid`	Connection id. Unused for IGMP.
`cs_pid`	Process ID. Unused for IGMP.
`cs_zoneid`	Zone ID associated with the connection.

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`ipinfo_t` structure

The ipinfo_t structure contains common IP info for both IPv4 and IPv6.

typedef struct ipinfo {
        uint8_t ip_ver;                 /* IP version (4, 6) */
        uint16_t ip_plength;            /* payload length */
        string ip_saddr;                /* source address */
        string ip_daddr;                /* destination address */
} ipinfo_t;

`ipinfo_t` Members

`ip_ver`	IP version number. Currently either 4 or 6. For IGMP, it will always be 4 since it is an IPv4-only protocol.
`ip_plength`	Payload length in bytes. This is the length of the packet at the time of tracing, excluding the IP header.
`ip_saddr`	Source IP address, as a string. For IPv4 this is a dotted decimal quad.
`ip_daddr`	Destination IP address, as a string. For IPv4 this is a dotted decimal quad.

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`ifinfo_t` structure

The ifinfo_t structure contains interface.

typedef struct ifinfo {
        string if_name;                 /* interface name */
        uintptr_t if_addr;              /* pointer to raw ill_t */
} ifinfo_t;

`ifinfo_t` Members

`if_name`	IP interface name.
`if_addr`	Pointer to raw ill_t.

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`igmpinfo_t` structure

The igmpinfo_t structure is a DTrace translated version of the information contained in the various forms of IGMP header.

typedef struct igmpinfo {
        uint8_t igmp_type;
        uint8_t igmp_code;
        uint16_t igmp_checksum;
        string igmp_group_addr;
        uint8_t igmp_query_version;
        uint8_t igmp_v3_query_max_response_time;
        uint16_t igmp_v3_query_num_sources;
        uintptr_t igmp_v3_query_sources;
        uint16_t igmp_v3_report_num_records;
        struct grphdr *igmp_v3_report_records;
        struct igmp *igmp_hdr;
} igmpinfo_t;

`igmpinfo_t` Members

`igmp_type`	IGMP message type.
`igmp_code`	IGMP message code.
`igmp_checksum`	Checksum of IGMP header and payload.
`igmp_group_addr`	String representation of IGMP multicast group address. Not valid for IGMPv3 membership reports.
`igmp_query_version`	For an IGMP membership query, this field is set to 1, 2, or 3. Otherwise 0.
`igmp_v3_query_max_response_time`	Valid for an IGMPv3 membership query.
`igmp_v3_query_num_sources`	Number of IPv4 addresses specifying sources for group-and-source queries.
`igmp_v3_query_sources`	Array of IPv4 addresses specifying sources for group-and-source queries.
`igmp_v3_report_num_records`	Number of IGMPv3 group records specifying sources for group-and-source queries.
`igmp_v3_report_records`	Array of IGMPv3 group records specifying group and sources for group-and-source reports.
`igmp_hdr`	Pointer to raw IGMP header at time of tracing.

See RFCs 1112, 2236, 3376 for a detailed explanation of the various IGMP message header formats.

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Examples

Some simple examples of igmp provider usage follow.

IGMP traffic by zone.

This DTrace one-liner monitors IGMP traffic sent and received by type.

# dtrace -n 'igmp:::send,igmp:::receive { @[igmp_type_string[args[4]->igmp_type], probename, args[1]->cs_zoneid] = count(); }'
dtrace: description 'igmp:::send,igmp:::receive ' matched 3 probes
^C

  membership query                                    receive                                                   0                1
  v1 membership report                                receive                                                   0                1
  v1 membership report                                send                                                      0                1

We see above that in the global zone (zoneid 0) we received one membership query and one membership report, and sent one membership report.

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`igmp` Stability

The igmp provider uses DTrace's stability mechanism to describe its stabilities, as shown in the following table. For more information about the stability mechanism, see Chapter 39, Stability.

Element	Name stability	Data stability	Dependency class
Provider	Evolving	Evolving	ISA
Module	Private	Private	Unknown
Function	Private	Private	Unknown
Name	Evolving	Evolving	ISA
Arguments	Evolving	Evolving	ISA

igmp provider

igmp Provider

Probes

igmp Probes

Arguments

igmp Probe Arguments

pktinfo_t structure

csinfo_t structure

csinfo_t Members

ipinfo_t structure

ipinfo_t Members

ifinfo_t structure

ifinfo_t Members

igmpinfo_t structure

igmpinfo_t Members