bacnet_encoding/constructed/
mod.rs

1//! Full ASN.1 framing codecs for constructed Clause-21 types whose property
2//! values are CHOICE/SEQUENCE productions — context-tagged framing per
3//! ASHRAE 135-2020 Clause 20.2.1.5/20.2.1.6.
4//!
5//! These codecs encode to and decode from raw application-layer bytes, the
6//! same bytes carried by [`bacnet_types::primitives::PropertyValue::ApplicationData`].
7//! Objects serve framed properties (e.g. `Event_Parameters`,
8//! `Fault_Parameters`, `Recipient_List`) by encoding with these functions;
9//! the flat application-tagged model in [`crate::primitives::encode_property_value`]
10//! cannot express their wire form.
11//!
12//! Tag-form rules applied here:
13//!
14//! - A CHOICE alternative over a `SEQUENCE` is an opening/closing context tag
15//!   pair around the SEQUENCE's members.
16//! - A CHOICE alternative over a primitive base type is a context-specific
17//!   primitive tag holding the raw contents (e.g. `none [0] NULL`).
18//! - A context-tagged inner `CHOICE` is always explicitly tagged: an
19//!   opening/closing pair around the alternative's own encoding.
20//! - Inner members declared `[n] T` over primitive `T` are context-tagged
21//!   primitives; inner `SEQUENCE OF` / embedded `SEQUENCE` members are
22//!   constructed opening/closing pairs holding application-tagged elements.
23
24use bacnet_types::constructed::{
25    BACnetDeviceObjectPropertyReference, BACnetExtendedPropertyState, BACnetPropertyStates,
26    BACnetProprietaryPropertyState,
27};
28use bacnet_types::error::Error;
29use bytes::BytesMut;
30
31use crate::primitives;
32use crate::tags::{self, TagClass};
33use tagged::{
34    contents, decode_ctx_object_id, decode_ctx_unsigned, decode_optional_ctx, expect_closing,
35    expect_end, expect_opening,
36};
37
38pub mod access_credential;
39pub mod access_rule;
40mod action_list;
41pub mod assigned_landing_calls;
42mod audit_notification;
43mod audit_record;
44pub mod authentication_policy;
45pub mod calendar;
46mod channel_value;
47mod color_command;
48pub mod cov_subscription;
49mod event_log_record;
50mod event_notification;
51pub mod event_notification_subscription;
52pub mod event_parameter;
53pub mod fault_parameter;
54mod floor_pairs;
55pub mod landing_call_status;
56pub mod landing_door_status;
57pub mod lift_car_call_list;
58mod lighting_command;
59mod log_fields;
60mod log_multiple_record;
61mod log_record;
62mod members;
63mod name_value;
64pub mod network_port;
65pub mod object_property_reference;
66pub mod port_permission;
67mod property_access_result;
68mod property_value;
69mod read_access;
70pub mod recipient;
71mod scale;
72pub mod schedule;
73mod shed_level;
74pub mod staging;
75pub mod tagged;
76mod value_source;
77
78pub use access_credential::{
79    decode_assigned_access_rights, decode_authentication_factor,
80    decode_authentication_factor_format, decode_credential_authentication_factor,
81    encode_assigned_access_rights, encode_authentication_factor,
82    encode_authentication_factor_format, encode_credential_authentication_factor,
83};
84pub use access_rule::{decode_access_rule, encode_access_rule};
85pub use action_list::{
86    decode_action_command, decode_action_list, encode_action_command, encode_action_list,
87};
88pub use assigned_landing_calls::{decode_assigned_landing_calls, encode_assigned_landing_calls};
89pub use audit_notification::{decode_audit_notification_at, encode_audit_notification};
90pub use audit_record::{
91    decode_audit_log_record, decode_audit_log_record_at, decode_audit_log_record_result_at,
92    encode_audit_log_record, encode_audit_log_record_result,
93};
94pub use authentication_policy::{decode_authentication_policy, encode_authentication_policy};
95pub use calendar::{
96    decode_calendar_entry, decode_calendar_entry_list, decode_date_range, encode_calendar_entry,
97    encode_calendar_entry_list, encode_date_range,
98};
99pub use channel_value::{channel_value_end, constructed_channel_value, ConstructedChannelValue};
100pub use color_command::{
101    decode_color_command, decode_color_command_value, decode_xy_color, encode_color_command,
102    encode_xy_color,
103};
104pub use cov_subscription::{
105    decode_cov_multiple_subscription, decode_cov_subscription, encode_cov_multiple_subscription,
106    encode_cov_multiple_subscription_list, encode_cov_subscription, encode_cov_subscription_list,
107};
108pub use event_log_record::{decode_event_log_record, encode_event_log_record};
109pub use event_notification::{
110    decode_event_notification, decode_event_notification_tolerant, decode_notification_parameters,
111    encode_event_notification, encode_notification_parameters,
112};
113pub use event_notification_subscription::{
114    decode_event_notification_subscription, encode_event_notification_subscription,
115    encode_event_notification_subscription_list,
116};
117pub use event_parameter::{decode_event_parameter, encode_event_parameter};
118pub use fault_parameter::{decode_fault_parameters, encode_fault_parameters};
119pub use landing_call_status::{
120    decode_landing_call_status, decode_landing_call_status_list, encode_landing_call_status,
121    encode_landing_call_status_list,
122};
123pub use landing_door_status::{decode_landing_door_status, encode_landing_door_status};
124pub use lift_car_call_list::{decode_lift_car_call_list, encode_lift_car_call_list};
125pub use lighting_command::{
126    decode_lighting_command, decode_lighting_command_value, encode_lighting_command,
127};
128pub use log_multiple_record::{decode_log_multiple_record, encode_log_multiple_record};
129pub use log_record::{decode_log_record, encode_log_record};
130pub use name_value::{decode_name_value, encode_name_value};
131pub use network_port::{
132    decode_bdt_entry, decode_bdt_entry_list, decode_fdt_entry, decode_fdt_entry_list,
133    decode_host_address, decode_host_n_port, encode_bdt_entry, encode_bdt_entry_list,
134    encode_fdt_entry, encode_fdt_entry_list, encode_host_address, encode_host_n_port,
135};
136pub use object_property_reference::{
137    decode_object_property_reference, decode_object_property_reference_at,
138    decode_setpoint_reference, decode_setpoint_reference_at, encode_object_property_reference,
139    encode_setpoint_reference,
140};
141pub use port_permission::{decode_port_permission, encode_port_permission};
142pub use property_access_result::{decode_property_access_result, encode_property_access_result};
143pub use property_value::{
144    decode_bacnet_property_value, decode_bacnet_property_value_in_list,
145    decode_bacnet_property_value_in_list_detailed, encode_bacnet_property_value,
146    extract_property_value, PropertyValueBoundary, PropertyValueDecodeError,
147    PropertyValueDecodeFailure, PropertyValueDecodeStage,
148};
149pub use read_access::{
150    decode_property_reference, decode_read_access_specification, encode_property_reference,
151    encode_read_access_specification,
152};
153pub use recipient::{
154    check_decoded_mac_len, check_encoded_mac_len, decode_destination, decode_destination_list,
155    decode_recipient, encode_destination, encode_destination_list, encode_recipient,
156};
157pub use scale::{decode_prescale, decode_scale, encode_prescale, encode_scale};
158pub use schedule::{
159    decode_daily_schedule, decode_exception_schedule, decode_special_event,
160    decode_special_event_period, decode_time_value, decode_weekly_schedule, encode_daily_schedule,
161    encode_exception_schedule, encode_special_event, encode_special_event_period,
162    encode_time_value, encode_weekly_schedule,
163};
164pub use shed_level::{decode_shed_level, encode_shed_level};
165pub use staging::{
166    decode_device_object_reference, decode_stage_limit_value, encode_device_object_reference,
167    encode_stage_limit_value,
168};
169
170pub use value_source::{decode_value_source, encode_value_source};
171
172/// Upper bound on decoded SEQUENCE OF / list lengths, mirroring the socket-
173/// facing posture of `bacnet-services`' `MAX_DECODED_ITEMS`. Prevents memory
174/// exhaustion from malformed framed payloads.
175const MAX_FRAMED_ITEMS: usize = 10_000;
176
177// ---------------------------------------------------------------------------
178// BACnetPropertyStates (Clause 21 CHOICE) — spec-tagged framing
179// ---------------------------------------------------------------------------
180
181/// Encode a [`BACnetPropertyStates`] using the Standard 135-2020 Clause 21 tags.
182///
183/// Returns an error without modifying `buf` when a constructed proprietary
184/// value does not contain a BACnet TLV sequence.
185pub fn encode_property_state(
186    buf: &mut BytesMut,
187    state: &BACnetPropertyStates,
188) -> Result<(), Error> {
189    use BACnetPropertyStates as S;
190    if let S::Other(value) = state {
191        if value.is_constructed() {
192            validate_tlv_sequence(value.data(), "proprietary property-state body")?;
193            let mut framed = BytesMut::new();
194            tags::encode_opening_tag(&mut framed, value.tag());
195            let (_, body_start) = tags::decode_tag(&framed, 0)?;
196            framed.extend_from_slice(value.data());
197            tags::encode_closing_tag(&mut framed, value.tag());
198            let (_, end) = tags::extract_context_value(&framed, body_start, value.tag())?;
199            expect_end(&framed, end, end, "proprietary property-state body")?;
200        }
201    }
202    match state {
203        S::BooleanValue(v) => primitives::encode_ctx_boolean(buf, 0, *v),
204        S::BinaryValue(v) => primitives::encode_ctx_enumerated(buf, 1, *v),
205        S::EventType(v) => primitives::encode_ctx_enumerated(buf, 2, *v),
206        S::Polarity(v) => primitives::encode_ctx_enumerated(buf, 3, *v),
207        S::ProgramChange(v) => primitives::encode_ctx_enumerated(buf, 4, *v),
208        S::ProgramState(v) => primitives::encode_ctx_enumerated(buf, 5, *v),
209        S::ReasonForHalt(v) => primitives::encode_ctx_enumerated(buf, 6, *v),
210        S::Reliability(v) => primitives::encode_ctx_enumerated(buf, 7, *v),
211        S::State(v) => primitives::encode_ctx_enumerated(buf, 8, *v),
212        S::SystemStatus(v) => primitives::encode_ctx_enumerated(buf, 9, *v),
213        S::Units(v) => primitives::encode_ctx_enumerated(buf, 10, *v),
214        S::UnsignedValue(v) => primitives::encode_ctx_unsigned(buf, 11, *v as u64),
215        S::LifeSafetyMode(v) => primitives::encode_ctx_enumerated(buf, 12, *v),
216        S::LifeSafetyState(v) => primitives::encode_ctx_enumerated(buf, 13, *v),
217        S::RestartReason(v) => primitives::encode_ctx_enumerated(buf, 14, *v),
218        S::DoorAlarmState(v) => primitives::encode_ctx_enumerated(buf, 15, *v),
219        S::Action(v) => primitives::encode_ctx_enumerated(buf, 16, *v),
220        S::DoorSecuredStatus(v) => primitives::encode_ctx_enumerated(buf, 17, *v),
221        S::DoorStatus(v) => primitives::encode_ctx_enumerated(buf, 18, *v),
222        S::DoorValue(v) => primitives::encode_ctx_enumerated(buf, 19, *v),
223        S::FileAccessMethod(v) => primitives::encode_ctx_enumerated(buf, 20, *v),
224        S::LockStatus(v) => primitives::encode_ctx_enumerated(buf, 21, *v),
225        S::LifeSafetyOperation(v) => primitives::encode_ctx_enumerated(buf, 22, *v),
226        S::Maintenance(v) => primitives::encode_ctx_enumerated(buf, 23, *v),
227        S::NodeType(v) => primitives::encode_ctx_enumerated(buf, 24, *v),
228        S::NotifyType(v) => primitives::encode_ctx_enumerated(buf, 25, *v),
229        S::ShedState(v) => primitives::encode_ctx_enumerated(buf, 27, *v),
230        S::SilencedState(v) => primitives::encode_ctx_enumerated(buf, 28, *v),
231        S::AccessEvent(v) => primitives::encode_ctx_enumerated(buf, 30, *v),
232        S::ZoneOccupancyState(v) => primitives::encode_ctx_enumerated(buf, 31, *v),
233        S::AccessCredentialDisableReason(v) => primitives::encode_ctx_enumerated(buf, 32, *v),
234        S::AccessCredentialDisable(v) => primitives::encode_ctx_enumerated(buf, 33, *v),
235        S::AuthenticationStatus(v) => primitives::encode_ctx_enumerated(buf, 34, *v),
236        S::BackupState(v) => primitives::encode_ctx_enumerated(buf, 36, *v),
237        S::WriteStatus(v) => primitives::encode_ctx_enumerated(buf, 37, *v),
238        S::LightingInProgress(v) => primitives::encode_ctx_enumerated(buf, 38, *v),
239        S::LightingOperation(v) => primitives::encode_ctx_enumerated(buf, 39, *v),
240        S::LightingTransition(v) => primitives::encode_ctx_enumerated(buf, 40, *v),
241        S::IntegerValue(v) => primitives::encode_ctx_signed(buf, 41, *v),
242        S::BinaryLightingValue(v) => primitives::encode_ctx_enumerated(buf, 42, *v),
243        S::TimerState(v) => primitives::encode_ctx_enumerated(buf, 43, *v),
244        S::TimerTransition(v) => primitives::encode_ctx_enumerated(buf, 44, *v),
245        S::BacnetIpMode(v) => primitives::encode_ctx_enumerated(buf, 45, *v),
246        S::NetworkPortCommand(v) => primitives::encode_ctx_enumerated(buf, 46, *v),
247        S::NetworkType(v) => primitives::encode_ctx_enumerated(buf, 47, *v),
248        S::NetworkNumberQuality(v) => primitives::encode_ctx_enumerated(buf, 48, *v),
249        S::EscalatorOperationDirection(v) => primitives::encode_ctx_enumerated(buf, 49, *v),
250        S::EscalatorFault(v) => primitives::encode_ctx_enumerated(buf, 50, *v),
251        S::EscalatorMode(v) => primitives::encode_ctx_enumerated(buf, 51, *v),
252        S::LiftCarDirection(v) => primitives::encode_ctx_enumerated(buf, 52, *v),
253        S::LiftCarDoorCommand(v) => primitives::encode_ctx_enumerated(buf, 53, *v),
254        S::LiftCarDriveStatus(v) => primitives::encode_ctx_enumerated(buf, 54, *v),
255        S::LiftCarMode(v) => primitives::encode_ctx_enumerated(buf, 55, *v),
256        S::LiftGroupMode(v) => primitives::encode_ctx_enumerated(buf, 56, *v),
257        S::LiftFault(v) => primitives::encode_ctx_enumerated(buf, 57, *v),
258        S::ProtocolLevel(v) => primitives::encode_ctx_enumerated(buf, 58, *v),
259        S::AuditLevel(v) => primitives::encode_ctx_enumerated(buf, 59, *v),
260        S::AuditOperation(v) => primitives::encode_ctx_enumerated(buf, 60, *v),
261        S::ExtendedValue(v) => primitives::encode_ctx_unsigned(buf, 63, v.encoded() as u64),
262        S::Other(v) if v.is_constructed() => {
263            tags::encode_opening_tag(buf, v.tag());
264            buf.extend_from_slice(v.data());
265            tags::encode_closing_tag(buf, v.tag());
266        }
267        S::Other(v) => primitives::encode_ctx_octet_string(buf, v.tag(), v.data()),
268    }
269    Ok(())
270}
271
272/// Decode one [`BACnetPropertyStates`] CHOICE element at `offset`.
273///
274/// Proprietary tags 64 through 254 retain their encoded contents in
275/// [`BACnetPropertyStates::Other`]. Reserved standard tags are rejected.
276pub fn decode_property_state(
277    data: &[u8],
278    offset: usize,
279) -> Result<(BACnetPropertyStates, usize), Error> {
280    use BACnetPropertyStates as S;
281    let (tag, pos) = tags::decode_tag(data, offset)?;
282    if tag.class != TagClass::Context || tag.is_closing {
283        return Err(tagged::misplaced_tag(
284            data,
285            &tag,
286            None,
287            offset,
288            "BACnetPropertyStates: expected a context tag",
289        ));
290    }
291    if tag.is_opening {
292        if !(64..=254).contains(&tag.number) {
293            return Err(Error::invalid_tag(
294                offset,
295                "BACnetPropertyStates: constructed form requires a proprietary tag",
296            ));
297        }
298        let (content, end) = tags::extract_context_value(data, pos, tag.number)?;
299        validate_tlv_sequence(content, "proprietary property-state body")?;
300        return Ok((
301            S::Other(BACnetProprietaryPropertyState::constructed(
302                tag.number,
303                content.to_vec(),
304            )?),
305            end,
306        ));
307    }
308    let (content, end) = contents(data, pos, tag.length)?;
309    let unsigned = || -> Result<u32, Error> {
310        u32::try_from(primitives::decode_unsigned(content)?)
311            .map_err(|_| Error::out_of_range(pos, "BACnetPropertyStates: contents exceed u32"))
312    };
313    let state = match tag.number {
314        0 => {
315            if content.len() != 1 {
316                return Err(Error::decoding(
317                    offset,
318                    format!(
319                        "BACnetPropertyStates boolean-value: expected 1 contents octet, got {}",
320                        content.len()
321                    ),
322                ));
323            }
324            match content[0] {
325                0 => S::BooleanValue(false),
326                1 => S::BooleanValue(true),
327                value => {
328                    return Err(Error::decoding(
329                        pos,
330                        format!("BACnetPropertyStates boolean-value must be 0 or 1, got {value}"),
331                    ));
332                }
333            }
334        }
335        1 => S::BinaryValue(unsigned()?),
336        2 => S::EventType(unsigned()?),
337        3 => S::Polarity(unsigned()?),
338        4 => S::ProgramChange(unsigned()?),
339        5 => S::ProgramState(unsigned()?),
340        6 => S::ReasonForHalt(unsigned()?),
341        7 => S::Reliability(unsigned()?),
342        8 => S::State(unsigned()?),
343        9 => S::SystemStatus(unsigned()?),
344        10 => S::Units(unsigned()?),
345        11 => S::UnsignedValue(unsigned()?),
346        12 => S::LifeSafetyMode(unsigned()?),
347        13 => S::LifeSafetyState(unsigned()?),
348        14 => S::RestartReason(unsigned()?),
349        15 => S::DoorAlarmState(unsigned()?),
350        16 => S::Action(unsigned()?),
351        17 => S::DoorSecuredStatus(unsigned()?),
352        18 => S::DoorStatus(unsigned()?),
353        19 => S::DoorValue(unsigned()?),
354        20 => S::FileAccessMethod(unsigned()?),
355        21 => S::LockStatus(unsigned()?),
356        22 => S::LifeSafetyOperation(unsigned()?),
357        23 => S::Maintenance(unsigned()?),
358        24 => S::NodeType(unsigned()?),
359        25 => S::NotifyType(unsigned()?),
360        27 => S::ShedState(unsigned()?),
361        28 => S::SilencedState(unsigned()?),
362        30 => S::AccessEvent(unsigned()?),
363        31 => S::ZoneOccupancyState(unsigned()?),
364        32 => S::AccessCredentialDisableReason(unsigned()?),
365        33 => S::AccessCredentialDisable(unsigned()?),
366        34 => S::AuthenticationStatus(unsigned()?),
367        36 => S::BackupState(unsigned()?),
368        37 => S::WriteStatus(unsigned()?),
369        38 => S::LightingInProgress(unsigned()?),
370        39 => S::LightingOperation(unsigned()?),
371        40 => S::LightingTransition(unsigned()?),
372        41 => S::IntegerValue(primitives::decode_signed_canonical(content)?),
373        42 => S::BinaryLightingValue(unsigned()?),
374        43 => S::TimerState(unsigned()?),
375        44 => S::TimerTransition(unsigned()?),
376        45 => S::BacnetIpMode(unsigned()?),
377        46 => S::NetworkPortCommand(unsigned()?),
378        47 => S::NetworkType(unsigned()?),
379        48 => S::NetworkNumberQuality(unsigned()?),
380        49 => S::EscalatorOperationDirection(unsigned()?),
381        50 => S::EscalatorFault(unsigned()?),
382        51 => S::EscalatorMode(unsigned()?),
383        52 => S::LiftCarDirection(unsigned()?),
384        53 => S::LiftCarDoorCommand(unsigned()?),
385        54 => S::LiftCarDriveStatus(unsigned()?),
386        55 => S::LiftCarMode(unsigned()?),
387        56 => S::LiftGroupMode(unsigned()?),
388        57 => S::LiftFault(unsigned()?),
389        58 => S::ProtocolLevel(unsigned()?),
390        59 => S::AuditLevel(unsigned()?),
391        60 => S::AuditOperation(unsigned()?),
392        63 => S::ExtendedValue(BACnetExtendedPropertyState::from_encoded(unsigned()?)?),
393        other @ 64..=254 => S::Other(BACnetProprietaryPropertyState::primitive(
394            other,
395            content.to_vec(),
396        )?),
397        reserved => {
398            return Err(Error::invalid_tag(
399                offset,
400                format!("BACnetPropertyStates context tag {reserved} is reserved"),
401            ));
402        }
403    };
404    Ok((state, end))
405}
406
407// ---------------------------------------------------------------------------
408// BACnetDeviceObjectPropertyReference (Clause 21 SEQUENCE)
409// ---------------------------------------------------------------------------
410
411/// Encode the context-tagged members of a `BACnetDeviceObjectPropertyReference`:
412/// `object-identifier [0]`, `property-identifier [1]`, optional
413/// `property-array-index [2]`, optional `device-identifier [3]` — the body
414/// that sits between the enclosing field's opening/closing tags.
415pub(crate) fn encode_dopr_body(buf: &mut BytesMut, r: &BACnetDeviceObjectPropertyReference) {
416    primitives::encode_ctx_object_id(buf, 0, &r.object_identifier);
417    primitives::encode_ctx_unsigned(buf, 1, r.property_identifier as u64);
418    if let Some(index) = r.property_array_index {
419        primitives::encode_ctx_unsigned(buf, 2, index as u64);
420    }
421    if let Some(ref device) = r.device_identifier {
422        primitives::encode_ctx_object_id(buf, 3, device);
423    }
424}
425
426/// Decode the members written by [`encode_dopr_body`], stopping before the
427/// enclosing closing tag.
428pub(crate) fn decode_dopr_body(
429    data: &[u8],
430    offset: usize,
431    what: &str,
432) -> Result<(BACnetDeviceObjectPropertyReference, usize), Error> {
433    let (object_identifier, offset) = decode_ctx_object_id(data, offset, 0, what)?;
434    let (property_identifier, offset) = decode_ctx_unsigned::<u32>(data, offset, 1, what)?;
435    let (property_array_index, offset) =
436        decode_optional_ctx(data, offset, 2, what, decode_ctx_unsigned::<u32>)?;
437    let (device_identifier, offset) =
438        decode_optional_ctx(data, offset, 3, what, decode_ctx_object_id)?;
439    Ok((
440        BACnetDeviceObjectPropertyReference {
441            object_identifier,
442            property_identifier,
443            property_array_index,
444            device_identifier,
445        },
446        offset,
447    ))
448}
449
450/// Encode one bare `BACnetDeviceObjectPropertyReference`, the counterpart of
451/// [`decode_device_object_property_reference`]: its members with no enclosing
452/// frame, so a BACnetLIST of these references is their encodings back to back.
453pub fn encode_device_object_property_reference(
454    buf: &mut BytesMut,
455    r: &BACnetDeviceObjectPropertyReference,
456) {
457    encode_dopr_body(buf, r);
458}
459
460/// Decode one bare `BACnetDeviceObjectPropertyReference` at `offset`; returns
461/// it and the offset past its last member. A BACnetLIST of these references
462/// concatenates its elements with no frame, so walking the list calls this at
463/// each element's start.
464pub fn decode_device_object_property_reference(
465    data: &[u8],
466    offset: usize,
467) -> Result<(BACnetDeviceObjectPropertyReference, usize), Error> {
468    decode_dopr_body(data, offset, "BACnetDeviceObjectPropertyReference")
469}
470
471/// Validate a BACnet TLV sequence without normalizing its encoded values.
472///
473/// This checks matching context tags, the context nesting limit, and
474/// application-value forms while preserving defined CharacterString encodings.
475pub fn validate_tlv_sequence(data: &[u8], what: &str) -> Result<(), Error> {
476    let mut offset = 0;
477    let mut count = 0;
478    while offset < data.len() {
479        if count >= MAX_FRAMED_ITEMS {
480            return Err(Error::overflow(
481                offset,
482                format!("{what}: sequence exceeds item limit"),
483            ));
484        }
485        let (tag, content) = tags::decode_tag(data, offset)?;
486        if tag.is_opening {
487            let (inner, next) = tags::extract_context_value(data, content, tag.number)?;
488            validate_tlv_sequence(inner, what)?;
489            offset = next;
490        } else if tag.class == TagClass::Application {
491            offset = primitives::validate_application_value(data, offset)?;
492        } else {
493            let (_, next) = primitives::decode_application_value(data, offset)?;
494            offset = next;
495        }
496        count += 1;
497    }
498    Ok(())
499}
500
501/// Validate the shared Extended Event/Fault `parameters` production.
502/// Its only context-tagged CHOICE is `reference [0]` over
503/// `BACnetDeviceObjectPropertyReference`; NotificationParameters uses a
504/// different Extended production with `property-value [0]`.
505pub(crate) fn validate_extended_parameters(data: &[u8], what: &str) -> Result<(), Error> {
506    let mut offset = 0;
507    let mut count = 0;
508    while offset < data.len() {
509        if count >= MAX_FRAMED_ITEMS {
510            return Err(Error::overflow(
511                offset,
512                format!("{what}: parameters exceed item limit"),
513            ));
514        }
515        let (tag, _) = tags::decode_tag(data, offset)?;
516        if tag.class == TagClass::Context {
517            let content = expect_opening(data, offset, 0, what)?;
518            let (_, after_reference) = decode_dopr_body(data, content, what)?;
519            offset = expect_closing(data, after_reference, 0, what)?;
520        } else {
521            offset = primitives::validate_application_value(data, offset)?;
522        }
523        count += 1;
524    }
525    Ok(())
526}
527
528#[cfg(test)]
529pub(crate) mod tests;
bacnet_encoding/constructed/mod.rs

bacnet_encoding/constructed/
mod.rs
