1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
// Copyright 2025 LiveKit, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::{
error::Error,
fmt::{Display, Formatter},
};
// cxx doesn't support custom Exception type, so we serialize RtcError inside the cxx::Exception
// "what" string
#[cxx::bridge(namespace = "livekit_ffi")]
pub mod ffi {
#[derive(Debug)]
#[repr(i32)]
pub enum RtcErrorType {
None,
UnsupportedOperation,
UnsupportedParameter,
InvalidParameter,
InvalidRange,
SyntaxError,
InvalidState,
InvalidModification,
NetworkError,
ResourceExhausted,
InternalError,
OperationErrorWithData,
}
#[derive(Debug)]
#[repr(i32)]
pub enum RtcErrorDetailType {
None,
DataChannelFailure,
DtlsFailure,
FingerprintFailure,
SctpFailure,
SdpSyntaxError,
HardwareEncoderNotAvailable,
HardwareEncoderError,
}
#[derive(Debug)]
pub struct RtcError {
pub error_type: RtcErrorType,
pub message: String,
pub error_detail: RtcErrorDetailType,
// cxx doesn't support the Option trait
pub has_sctp_cause_code: bool,
pub sctp_cause_code: u16,
}
}
impl ffi::RtcError {
/// Parse the hex-encoded error string the C++ side stuffs into the
/// `cxx::Exception` "what" message (see `webrtc-sys/src/rtc_error.cpp`
/// `serialize_error`). The format is fixed-width:
///
/// ```text
/// bytes 0..8 error_type (u32 hex)
/// bytes 8..16 error_detail (u32 hex)
/// bytes 16..18 has_sctp_cause_code (u8 hex, 0 or 1)
/// bytes 18..22 sctp_cause_code (u16 hex)
/// bytes 22.. message (raw, not encoded)
/// ```
///
/// Returns `None` if the input is shorter than the fixed header or the
/// header bytes aren't valid hex. Discriminants outside the known
/// variants for `RtcErrorType` / `RtcErrorDetailType` fall back to
/// `None` for the affected field instead of being `transmute`d into
/// the enum (which is instant UB and what nightly's
/// `ptr::copy_nonoverlapping` precondition check was firing on).
pub fn parse(value: &str) -> Option<Self> {
if value.len() < 22 {
return None;
}
let error_type = u32::from_str_radix(&value[0..8], 16).ok()?;
let error_detail = u32::from_str_radix(&value[8..16], 16).ok()?;
let has_scp_cause_code = u8::from_str_radix(&value[16..18], 16).ok()?;
let sctp_cause_code = u16::from_str_radix(&value[18..22], 16).ok()?;
let message = String::from(&value[22..]);
Some(Self {
error_type: rtc_error_type_from_u32(error_type),
error_detail: rtc_error_detail_type_from_u32(error_detail),
sctp_cause_code,
has_sctp_cause_code: has_scp_cause_code == 1,
message,
})
}
/// Backwards-compatible wrapper for callers that already trust the input
/// is well-formed.
///
/// # Safety
/// Marked `unsafe` purely for source-compat with prior callers; the body
/// no longer relies on caller-upheld invariants.
pub unsafe fn from(value: &str) -> Self {
Self::parse(value).expect("malformed serialized RtcError")
}
pub fn ok(&self) -> bool {
self.error_type == ffi::RtcErrorType::None
}
}
fn rtc_error_type_from_u32(value: u32) -> ffi::RtcErrorType {
match value {
0 => ffi::RtcErrorType::None,
1 => ffi::RtcErrorType::UnsupportedOperation,
2 => ffi::RtcErrorType::UnsupportedParameter,
3 => ffi::RtcErrorType::InvalidParameter,
4 => ffi::RtcErrorType::InvalidRange,
5 => ffi::RtcErrorType::SyntaxError,
6 => ffi::RtcErrorType::InvalidState,
7 => ffi::RtcErrorType::InvalidModification,
8 => ffi::RtcErrorType::NetworkError,
9 => ffi::RtcErrorType::ResourceExhausted,
10 => ffi::RtcErrorType::InternalError,
11 => ffi::RtcErrorType::OperationErrorWithData,
_ => ffi::RtcErrorType::None,
}
}
fn rtc_error_detail_type_from_u32(value: u32) -> ffi::RtcErrorDetailType {
match value {
0 => ffi::RtcErrorDetailType::None,
1 => ffi::RtcErrorDetailType::DataChannelFailure,
2 => ffi::RtcErrorDetailType::DtlsFailure,
3 => ffi::RtcErrorDetailType::FingerprintFailure,
4 => ffi::RtcErrorDetailType::SctpFailure,
5 => ffi::RtcErrorDetailType::SdpSyntaxError,
6 => ffi::RtcErrorDetailType::HardwareEncoderNotAvailable,
7 => ffi::RtcErrorDetailType::HardwareEncoderError,
_ => ffi::RtcErrorDetailType::None,
}
}
impl Error for ffi::RtcError {}
impl Display for ffi::RtcError {
fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
write!(f, "RtcError occurred {:?}: {}", self.error_type, self.message)
}
}
#[cfg(test)]
mod tests {
use crate::rtc_error::ffi::{RtcError, RtcErrorDetailType, RtcErrorType};
#[cxx::bridge(namespace = "livekit_ffi")]
pub mod ffi {
unsafe extern "C++" {
include!("livekit/rtc_error.h");
fn serialize_deserialize() -> String;
}
}
/// Tests that RtcError can correctly deserialize the hex-encoded
/// error format produced by C++ (see serialize_error in rtc_error.cpp).
#[test]
fn serialize_deserialize() {
let str = ffi::serialize_deserialize();
let error = unsafe { RtcError::from(&str) };
assert_eq!(error.error_type, RtcErrorType::InternalError);
assert_eq!(error.error_detail, RtcErrorDetailType::DataChannelFailure);
assert!(error.has_sctp_cause_code);
assert_eq!(error.sctp_cause_code, 24);
assert_eq!(error.message, "this is not a test, I repeat, this is not a test");
}
}