VND_CREATE(3VND)VND_CREATE(3VND)NAMEvnd_walk - walk all vnd devices
SYNOPSIS
cc [ flag... ] file... -lvnd [ library... ]
#include <libvnd.h>
typedef int (*vnd_walk_cb_f)(vnd_info_t *viip, void *cbarg);
int vnd_walk(vnd_walk_cb_t cb, void *arg, vnd_errno_t *vnderr, int *syserr);
DESCRIPTION
The vnd_walk() function fires the callback function cb once for every
vnd device that is visible in the current zone. If the caller is in the
global zone, then all vnd devices in all zones will be walked. If the
caller is in a non-global zone, then only the devices in that zone will
be visible.
The function cb will be called with two arguments. The first argument,
viip, is a pointer to a structure that contains information about the
link. The second argument to the function cb, cbarg, is the same argu‐
ment that is passed to the function vnd_walk as arg. To continue the
function cb should return zero. If the function cb returns non-zero the
walk will terminate.
As the vnd_walk function does not have a handle, errors are returned in
vnderr and syserr. Both vnderr and syserr are allowed to be NULL point‐
ers. If either one is a NULL pointer, then error information for that
class of error will not be returned. It is not recommended that con‐
sumers supply NULL pointers.
The vnd_info_t structure contains the following members:
uint32_t vi_version
zoneid_t vi_zone
char vi_name[LIBVND_NAMELEN];
char vi_datalink[LIBVND_NAMELEN];
The member vi_version is guaranteed to be the first member of the
structure. This number indicates the current revision of the structure
and is set to the integer value 1. More properties may be added in
future releases. Those properties will be tied to a greater version
number so software knows whether or not it is legal to access them.
The vi_zone field indicates the zone id that the vnd device exists in.
The vi_name field is the name of the vnd device. If the vnd_device is
not linked, the name field is set to "<unknown>". The vi_datalink field
is filled in with the name of the data link the vnd device is on top
of.
RETURN VALUES
The vnd_walk function will return zero on success. If the consumer sup‐
plied callback function returned non-zero, then the vnd_walk function
will return 1. If an error occurred, -1 is returned, and if vnderr and
syserr are non-null, they are filled in with their respective error
values. See vnd_errno(3VND) for more information on these errors.
EXAMPLES
Example 1 Walk all devices and print information about them
The following sample C program walks every vnd device and prints out
information about them.
#include <libvnd.h>
#include <stdio.h>
static int
print_entry(vnd_info_t *viip, void *unused)
{
(void) printf("device %s over data link %s in zone %d0,
viip->vi_name, viip->vi_datalink, viip->vi_zone);
return (0);
}
int
main(void)
{
vnd_errno_t vnderr;
int syserr;
if (vnd_walk(print_entry, NULL, &vnderr, &syserr) != 0) {
(void) fprintf(stderr, "failed to walk vnd devices: %s0,
vnderr != VND_E_SYS ? vnd_strerror(vnderr) :
vnd_strsyserror(syserr));
return (1);
}
return (0);
}
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│Stability │ Committed │
├───────────────┼─────────────────┤
│MT-Level │ MT-Safe │
└───────────────┴─────────────────┘
SEE ALSOlibvnd(3VND), vnd_errno(3VND), attributes(5), zones(5)
Feb 21, 2014 VND_CREATE(3VND)
