Struct PacPolicy 

pub struct PacPolicy { /* private fields */ }

Available on crate feature pac only.

Safety envelope for PAC evaluation (pac-quickjs and pac-subprocess; ignored by the native resolvers, which hand the script to the OS).

Defaults: no DNS, drop internal answers, myIpAddress() → 127.0.0.1, 5 s timeout. QuickJsEvaluator interrupts the script at the deadline, and bounds the heap and the native stack, the parser’s included, with fixed limits of its own.

One default is not a limit: the crate reads no time zone, so local_utc_offset is 0 and weekdayRange, dateRange and timeRange answer in GMT whether or not the script passed "GMT"; a browser reads the host’s zone there. with_local_utc_offset is the only way to move them, and a fixed offset does not follow DST.

The defaults restrict evaluation because scripts arrive over the network and standalone PAC libraries have had security vulnerabilities: pac-resolver escaped its Node.js vm and reached RCE (CVE-2021-23406), and pacparser had CVE-2023-37360.

Implementations

impl PacPolicy

pub fn new() -> Self

The default policy: no DNS, no internal addresses, no real local IP, 5 s budget.

pub fn with_dns_resolution(self, enabled: bool) -> Self

Allow dnsResolve, isResolvable and isInNet to perform name resolution.

With the default false, dnsResolve returns null and no DNS query is made.

pub fn with_internal_addresses(self, allowed: bool) -> Self

Allow answers in internal space (loopback, RFC 1918, link-local, CGNAT, … and the IPv4-mapped spelling of those). Default false drops them.

Classic dnsResolve is IPv4-only, so a native IPv6 answer (a ULA, say) never reaches this flag either way. IP literals in the script are never filtered.

pub fn with_my_ip_address(self, address: IpAddr) -> Self

Set the address myIpAddress() reports. Unset → 127.0.0.1 (no auto-discovery).

pub fn with_timeout(self, timeout: Option<Duration>) -> Self

Wall-clock budget, or None to remove it (blocks the caller if the script hangs).

Some(Duration::ZERO) is a zero budget, not an unlimited one: every evaluation returns Error::PacTimeout. None removes the limit. WinHttpPacResolver::with_timeout treats zero the same way. Its name is left unlinked because the type exists only under pac-windows-native on Windows; linking it breaks doc builds elsewhere.

QuickJsEvaluator interrupts the script at the deadline, so its thread is free for the next evaluation when the call returns, unless a host function (dnsResolve with DNS on) is still running then.

Evaluation threads are limited process-wide to the number of cores, with a minimum of 4. A thread holds its slot until its script ends, including after the call times out. When all slots are occupied, a call waits for one within the same budget and returns Error::PacSaturated without running the script if the budget expires. Run untrusted scripts in a process the caller can kill (pac-subprocess). With None, the in-process engine runs on the calling thread without a slot, bypassing the thread limit as well as the timeout. SubprocessEvaluator (pac-subprocess) still requires a slot and waits without a time limit for a slot and its worker’s response.

pub fn with_local_utc_offset(self, seconds: i32) -> Self

Seconds from UTC treated as “local” for date/time predicates (default 0 = GMT).

pub fn with_now(self, now: SystemTime) -> Self

Pin the clock the time-dependent host functions see.

Intended for tests and for reproducing a routing decision after the fact.

pub fn resolve_dns(&self) -> bool

Whether name resolution is permitted.

pub fn allow_internal_addresses(&self) -> bool

Whether resolution results in internal address space are kept.

pub fn my_ip_address(&self) -> IpAddr

The address myIpAddress() reports, or 127.0.0.1 when unset.

pub fn timeout(&self) -> Option<Duration>

The wall-clock evaluation budget.

pub fn local_utc_offset(&self) -> i32

The offset from UTC, in seconds, that counts as local time.

pub fn now(&self) -> Option<SystemTime>

The pinned clock, when with_now was used.

Trait Implementations

impl Clone for PacPolicy

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for PacPolicy

impl Debug for PacPolicy

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

Formats the value using the given formatter.

impl Default for PacPolicy

fn default() -> Self

Returns the “default value” for a type.

impl Eq for PacPolicy

impl PartialEq for PacPolicy

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for PacPolicy