Ubuntu Manpage: ping_iterator_get_info - Receive information about a host

NAME

       ping_iterator_get_info - Receive information about a host

SYNOPSIS

         #include <oping.h>

         int ping_iterator_get_info (pingobj_iter_t *iter,
                         int info,
                         void *buffer,
                         size_t *buffer_len);

DESCRIPTION

The ping_iterator_get_info method can be used on an host iterator to return various
information about the current host.

The iter argument is an iterator as returned by ping_iterator_get(3) or
ping_iterator_next(3).

The info argument specifies the type of information returned. Use the following defines:

PING_INFO_USERNAME
Return the hostname of the host the iterator points to as supplied by the user. This
is the name you passed to ping_host_add(3) and which you need to pass to
"ping_host_remove", too.

PING_INFO_HOSTNAME
Return the hostname of the host the iterator points to. Since the name is looked up
using the socket address this may differ from the hostname passed to ping_host_add(3).
The hostname is actually looked up every time you call this method, no cache is
involved within liboping.

It is recommended to include "netdb.h" and allocate NI_MAXHOST bytes of buffer.

PING_INFO_ADDRESS
Return the address used in ASCII (i.e. human readable) format. The address is looked
up every time you call this method. 40 bytes should be sufficient for the buffer (16
octets in hex format, seven colons and one null byte), but more won't hurt.

PING_INFO_FAMILY
Returns the address family of the host. The buffer should be big enough to hold an
integer. The value is either AF_INET or AF_INET6.

PING_INFO_LATENCY
Return the last measured latency or less than zero if the timeout occurred before a
echo response was received. The buffer should be big enough to hold a double value.

PING_INFO_DROPPED
Return the number of times that no response was received within the timeout. This
value is only increased but may wrap around at the 32 bit boundary. The buffer should
be big enough to hold a 32 bit integer, e. g. an "uint32_t".

PING_INFO_SEQUENCE
Return the last sequence number sent. This number is increased regardless of echo
responses being received or not. The buffer should hold an integer.

PING_INFO_IDENT
Return the ident that is put into every ICMP packet sent to this host. Per convention
this usually is the PID of the sending process, but since liboping can handle several
hosts in parallel it uses a (pseudo-)random number here. The buffer should be big
enough to hold an integer value.

PING_INFO_RECV_TTL
Returns the time to live (TTL) of the received network packets. This number depends on
the value that was used by the remote host when it sent the echo reply and has nothing
to do with the PING_OPT_TTL of ping_setopt(3). The buffer should be big enough to hold
an integer value.

PING_INFO_RECV_QOS
Returns the value of the Quality of Service (QoS) byte of the incoming IPv4 or IPv6
packet. This byte is not interpreted by liboping at all and may be DSCP / ECN or
precedence / ToS depending on your network setup. Please see the appropriate RFCs for
further information on values you can expect to receive. The buffer is expected to an
"uint8_t".

The buffer argument is a pointer to an appropriately sized area of memory where the result
of the call will be stored. The buffer_len value is used as input and output: When calling
ping_iterator_get_info it reports the size of the memory region pointed to by buffer. The
method will write the number of bytes actually written to the memory into buffer_len
before returning.

RETURN VALUE

       ping_iterator_get_info returns zero if it succeeds.

       EINVAL is returned if the value passed as info is unknown. Both, buffer and buffer_len,
       will be left untouched in this case.

       If the requested information didn't fit into buffer then the size that would have been
       needed is written into buffer_len; buffer itself is left untouched. The return value is
       ENOMEM in this case.

KNOWN BUGS

       •   PING_INFO_RECV_TTL is not available under Debian Etch due to a missing define in the
           header files.

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