Struct View 

pub struct View { /* private fields */ }

A view is a collection of OID subtrees defining accessible objects.

Views are used by VACM to determine which OIDs a user can access. Each view consists of included and/or excluded subtrees.

Example

use async_snmp::agent::View;
use async_snmp::oid;

// Create a view that includes the system MIB but excludes sysContact
let view = View::new()
    .include(oid!(1, 3, 6, 1, 2, 1, 1))        // system MIB
    .exclude(oid!(1, 3, 6, 1, 2, 1, 1, 4));    // sysContact

assert!(view.contains(&oid!(1, 3, 6, 1, 2, 1, 1, 1, 0)));   // sysDescr.0
assert!(!view.contains(&oid!(1, 3, 6, 1, 2, 1, 1, 4, 0)));  // sysContact.0
assert!(!view.contains(&oid!(1, 3, 6, 1, 2, 1, 2)));        // interfaces MIB

Implementations

impl View

pub fn new() -> Self

Create a new empty view.

An empty view contains no OIDs. Add subtrees with include() or exclude().

pub fn include(self, oid: Oid) -> Self

Add an included subtree to the view.

All OIDs starting with oid will be included in the view, unless excluded by a later exclude() call.

Example

use async_snmp::agent::View;
use async_snmp::oid;

let view = View::new()
    .include(oid!(1, 3, 6, 1, 2, 1))  // MIB-2
    .include(oid!(1, 3, 6, 1, 4, 1)); // enterprises

assert!(view.contains(&oid!(1, 3, 6, 1, 2, 1, 1, 0)));
assert!(view.contains(&oid!(1, 3, 6, 1, 4, 1, 99999, 1)));

pub fn include_masked(self, oid: Oid, mask: Vec<u8>) -> Self

Add an included subtree with a wildcard mask.

The mask allows wildcards at specific OID arc positions. See ViewSubtree::mask for mask format details.

Example

use async_snmp::agent::View;
use async_snmp::oid;

// Include ifDescr for any interface (mask makes arc 10 a wildcard)
let view = View::new()
    .include_masked(
        oid!(1, 3, 6, 1, 2, 1, 2, 2, 1, 2),  // ifDescr
        vec![0xFF, 0xC0]  // First 10 arcs must match
    );

assert!(view.contains(&oid!(1, 3, 6, 1, 2, 1, 2, 2, 1, 2, 1)));   // ifDescr.1
assert!(view.contains(&oid!(1, 3, 6, 1, 2, 1, 2, 2, 1, 2, 100))); // ifDescr.100

pub fn exclude(self, oid: Oid) -> Self

Add an excluded subtree to the view.

OIDs starting with oid will be excluded, even if they match an included subtree. Exclusions take precedence.

Example

use async_snmp::agent::View;
use async_snmp::oid;

let view = View::new()
    .include(oid!(1, 3, 6, 1, 2, 1, 1))     // system MIB
    .exclude(oid!(1, 3, 6, 1, 2, 1, 1, 6)); // except sysLocation

assert!(view.contains(&oid!(1, 3, 6, 1, 2, 1, 1, 1, 0)));  // sysDescr
assert!(!view.contains(&oid!(1, 3, 6, 1, 2, 1, 1, 6, 0))); // sysLocation

pub fn exclude_masked(self, oid: Oid, mask: Vec<u8>) -> Self

Add an excluded subtree with a wildcard mask.

See include_masked() for mask usage.

pub fn contains(&self, oid: &Oid) -> bool

Check if an OID is in this view.

Per RFC 3415 Section 5, when multiple subtrees match an OID, the longest matching subtree determines inclusion/exclusion. At equal lengths, exclude wins.

Example

use async_snmp::agent::View;
use async_snmp::oid;

let view = View::new()
    .include(oid!(1, 3, 6, 1, 2, 1))
    .exclude(oid!(1, 3, 6, 1, 2, 1, 25));  // host resources

assert!(view.contains(&oid!(1, 3, 6, 1, 2, 1, 1, 0)));
assert!(!view.contains(&oid!(1, 3, 6, 1, 2, 1, 25, 1, 0)));
assert!(!view.contains(&oid!(1, 3, 6, 1, 4, 1)));  // not included

pub fn check_subtree(&self, oid: &Oid) -> ViewCheckResult

Check subtree access status with 3-state result.

Unlike contains() which checks a single OID, this method determines the access status for an entire subtree. This enables optimizations for GETBULK/GETNEXT operations.

Returns:

• ViewCheckResult::Included: OID and all descendants are accessible
• ViewCheckResult::Excluded: OID and all descendants are not accessible
• ViewCheckResult::Ambiguous: Mixed permissions, check each OID individually

Trait Implementations

impl Clone for View

fn clone(&self) -> View

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for View

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for View

fn default() -> View

Returns the “default value” for a type.