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.
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.
SEE ALSO
ping_iterator_get(3), liboping(3)
AUTHOR
liboping is written by Florian octo Forster <octo at verplant.org>.
Its homepage can be found at <http://verplant.org/liboping/>.
(c) 2005-2009 by Florian octo Forster.