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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503
//! Error type from parsing a document, and the position where it occurred
use thiserror::Error;
use crate::types::policy::PolicyError;
use std::{borrow::Cow, fmt, sync::Arc};
/// A position within a directory object. Used to tell where an error
/// occurred.
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
#[non_exhaustive]
pub enum Pos {
/// The error did not occur at any particular position.
///
/// This can happen when the error is something like a missing entry:
/// the entry is supposed to go _somewhere_, but we can't say where.
None,
/// The error occurred at an unknown position.
///
/// We should avoid using this case.
Unknown,
/// The error occurred at an invalid offset within the string, or
/// outside the string entirely.
///
/// This can only occur because of an internal error of some kind.
Invalid(usize),
/// The error occurred at a particular byte within the string.
///
/// We try to convert these to a Pos before displaying them to the user.
Byte {
/// Byte offset within a string.
off: usize,
},
/// The error occurred at a particular line (and possibly at a
/// particular byte within the line.)
PosInLine {
/// Line offset within a string.
line: usize,
/// Byte offset within the line.
byte: usize,
},
/// The error occurred at a position in memory. This shouldn't be
/// exposed to the user, but rather should be mapped to a position
/// in the string.
Raw {
/// A raw pointer to the position where the error occurred.
ptr: *const u8,
},
}
// It's okay to send a Pos to another thread, even though its Raw
// variant contains a pointer. That's because we never dereference the
// pointer: we only compare it to another pointer representing a
// string.
//
// TODO: Find a better way to have Pos work.
unsafe impl Send for Pos {}
unsafe impl Sync for Pos {}
impl Pos {
/// Construct a Pos from an offset within a &str slice.
pub fn from_offset(s: &str, off: usize) -> Self {
if off > s.len() || !s.is_char_boundary(off) {
Pos::Invalid(off)
} else {
let s = &s[..off];
let last_nl = s.rfind('\n');
match last_nl {
Some(pos) => {
let newlines = s.bytes().filter(|b| *b == b'\n').count();
Pos::PosInLine {
line: newlines + 1,
byte: off - pos,
}
}
None => Pos::PosInLine {
line: 1,
byte: off + 1,
},
}
}
}
/// Construct a Pos from a slice of some other string. This
/// Pos won't be terribly helpful, but it may be converted
/// into a useful Pos with `within`.
pub fn at(s: &str) -> Self {
let ptr = s.as_ptr();
Pos::Raw { ptr }
}
/// Construct Pos from the end of some other string.
pub fn at_end_of(s: &str) -> Self {
let ending = &s[s.len()..];
Pos::at(ending)
}
/// Construct a position from a byte offset.
pub fn from_byte(off: usize) -> Self {
Pos::Byte { off }
}
/// Construct a position from a line and a byte offset within that line.
pub fn from_line(line: usize, byte: usize) -> Self {
Pos::PosInLine { line, byte }
}
/// If this position appears within `s`, and has not yet been mapped to
/// a line-and-byte position, return its offset.
pub(crate) fn offset_within(&self, s: &str) -> Option<usize> {
match self {
Pos::Byte { off } => Some(*off),
Pos::Raw { ptr } => offset_in(*ptr, s),
_ => None,
}
}
/// Given a position, if it was at a byte offset, convert it to a
/// line-and-byte position within `s`.
///
/// Requires that this position was actually generated from `s`.
/// If it was not, the results here may be nonsensical.
///
/// TODO: I wish I knew an efficient safe way to do this that
/// guaranteed that we we always talking about the right string.
#[must_use]
pub fn within(self, s: &str) -> Self {
match self {
Pos::Byte { off } => Self::from_offset(s, off),
Pos::Raw { ptr } => {
if let Some(off) = offset_in(ptr, s) {
Self::from_offset(s, off)
} else {
self
}
}
_ => self,
}
}
}
/// If `ptr` is within `s`, return its byte offset.
fn offset_in(ptr: *const u8, s: &str) -> Option<usize> {
// We need to confirm that 'ptr' falls within 's' in order
// to subtract it meaningfully and find its offset.
// Otherwise, we'll get a bogus result.
//
// Fortunately, we _only_ get a bogus result: we don't
// hit unsafe behavior.
let ptr_u = ptr as usize;
let start_u = s.as_ptr() as usize;
let end_u = (s.as_ptr() as usize) + s.len();
if start_u <= ptr_u && ptr_u < end_u {
Some(ptr_u - start_u)
} else {
None
}
}
impl fmt::Display for Pos {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
use Pos::*;
match self {
None => write!(f, ""),
Unknown => write!(f, " at unknown position"),
Invalid(off) => write!(f, " at invalid offset at index {}", off),
Byte { off } => write!(f, " at byte {}", off),
PosInLine { line, byte } => write!(f, " on line {}, byte {}", line, byte),
Raw { ptr } => write!(f, " at {:?}", ptr),
}
}
}
/// A variety of parsing error.
#[derive(Copy, Clone, Debug, derive_more::Display, PartialEq, Eq)]
#[non_exhaustive]
pub enum NetdocErrorKind {
/// An internal error in the parser: these should never happen.
#[display(fmt = "internal error")]
Internal,
/// Invoked an API in an incorrect manner.
#[display(fmt = "bad API usage")]
BadApiUsage,
/// An entry was found with no keyword.
#[display(fmt = "no keyword for entry")]
MissingKeyword,
/// An entry was found with no newline at the end.
#[display(fmt = "line truncated before newline")]
TruncatedLine,
/// A bad string was found in the keyword position.
#[display(fmt = "invalid keyword")]
BadKeyword,
/// We found an ill-formed "BEGIN FOO" tag.
#[display(fmt = "invalid PEM BEGIN tag")]
BadObjectBeginTag,
/// We found an ill-formed "END FOO" tag.
#[display(fmt = "invalid PEM END tag")]
BadObjectEndTag,
/// We found a "BEGIN FOO" tag with an "END FOO" tag that didn't match.
#[display(fmt = "mismatched PEM tags")]
BadObjectMismatchedTag,
/// We found a base64 object with an invalid base64 encoding.
#[display(fmt = "invalid base64 in object")]
BadObjectBase64,
/// The document is not supposed to contain more than one of some
/// kind of entry, but we found one anyway.
#[display(fmt = "duplicate entry")]
DuplicateToken,
/// The document is not supposed to contain any of some particular kind
/// of entry, but we found one anyway.
#[display(fmt = "unexpected entry")]
UnexpectedToken,
/// The document is supposed to contain any of some particular kind
/// of entry, but we didn't find one one anyway.
#[display(fmt = "didn't find required entry")]
MissingToken,
/// The document was supposed to have one of these, but not where we
/// found it.
#[display(fmt = "entry out of place")]
MisplacedToken,
/// We found more arguments on an entry than it is allowed to have.
#[display(fmt = "too many arguments")]
TooManyArguments,
/// We didn't fine enough arguments for some entry.
#[display(fmt = "too few arguments")]
TooFewArguments,
/// We found an object attached to an entry that isn't supposed to
/// have one.
#[display(fmt = "unexpected object")]
UnexpectedObject,
/// An entry was supposed to have an object, but it didn't.
#[display(fmt = "missing object")]
MissingObject,
/// We found an object on an entry, but the type was wrong.
#[display(fmt = "wrong object type")]
WrongObject,
/// We tried to find an argument that we were sure would be there,
/// but it wasn't!
///
/// This error should never occur in correct code; it should be
/// caught earlier by TooFewArguments.
#[display(fmt = "missing argument")]
MissingArgument,
/// We found an argument that couldn't be parsed.
#[display(fmt = "bad argument for entry")]
BadArgument,
/// We found an object that couldn't be parsed after it was decoded.
#[display(fmt = "bad object for entry")]
BadObjectVal,
/// There was some signature that we couldn't validate.
#[display(fmt = "couldn't validate signature")]
BadSignature, // TODO(nickm): say which kind of signature.
/// The object is not valid at the required time.
#[display(fmt = "couldn't validate time bound")]
BadTimeBound,
/// There was a tor version we couldn't parse.
#[display(fmt = "couldn't parse Tor version")]
BadTorVersion,
/// There was an ipv4 or ipv6 policy entry that we couldn't parse.
#[display(fmt = "invalid policy entry")]
BadPolicy,
/// An underlying byte sequence couldn't be decoded.
#[display(fmt = "decoding error")]
Undecodable,
/// Versioned document with an unrecognized version.
#[display(fmt = "unrecognized document version")]
BadDocumentVersion,
/// Unexpected document type
#[display(fmt = "unexpected document type")]
BadDocumentType,
/// We expected a kind of entry that we didn't find
#[display(fmt = "missing entry")]
MissingEntry,
/// Document or section started with wrong token
#[display(fmt = "Wrong starting token")]
WrongStartingToken,
/// Document or section ended with wrong token
#[display(fmt = "Wrong ending token")]
WrongEndingToken,
/// Items not sorted as expected
#[display(fmt = "Incorrect sort order")]
WrongSortOrder,
/// A consensus lifetime was ill-formed.
#[display(fmt = "Invalid consensus lifetime")]
InvalidLifetime,
/// Found an empty line in the middle of a document
#[display(fmt = "Empty line")]
EmptyLine,
}
/// The underlying source for an [`Error`](struct@Error).
#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub(crate) enum NetdocErrorSource {
/// An error when parsing a binary object.
#[error("Error parsing binary object")]
Bytes(#[from] tor_bytes::Error),
/// An error when parsing an exit policy.
#[error("Error parsing policy")]
Policy(#[from] PolicyError),
/// An error when parsing an integer.
#[error("Couldn't parse integer")]
Int(#[from] std::num::ParseIntError),
/// An error when parsing an IP or socket address.
#[error("Couldn't parse address")]
Address(#[from] std::net::AddrParseError),
/// An error when validating a signature.
#[error("Invalid signature")]
Signature(#[source] Arc<signature::Error>),
/// An error when validating a signature on an embedded binary certificate.
#[error("Invalid certificate")]
CertSignature(#[from] tor_cert::CertError),
/// An error caused by an expired or not-yet-valid descriptor.
#[error("Descriptor expired or not yet valid")]
UntimelyDescriptor(#[from] tor_checkable::TimeValidityError),
/// Invalid protocol versions.
#[error("Protocol versions")]
Protovers(#[from] tor_protover::ParseError),
/// A bug in our programming, or somebody else's.
#[error("Internal error or bug")]
Bug(#[from] tor_error::Bug),
}
impl NetdocErrorKind {
/// Construct a new Error with this kind.
#[must_use]
pub(crate) fn err(self) -> Error {
Error {
kind: self,
msg: None,
pos: Pos::Unknown,
source: None,
}
}
/// Construct a new error with this kind at a given position.
#[must_use]
pub(crate) fn at_pos(self, pos: Pos) -> Error {
self.err().at_pos(pos)
}
/// Construct a new error with this kind and a given message.
#[must_use]
pub(crate) fn with_msg<T>(self, msg: T) -> Error
where
T: Into<Cow<'static, str>>,
{
self.err().with_msg(msg)
}
}
impl From<signature::Error> for NetdocErrorSource {
fn from(err: signature::Error) -> Self {
NetdocErrorSource::Signature(Arc::new(err))
}
}
/// An error that occurred while parsing a directory object of some kind.
#[derive(Debug, Clone)]
#[non_exhaustive]
pub struct Error {
/// What kind of error occurred?
pub(crate) kind: NetdocErrorKind,
/// Do we have more information about the error?>
msg: Option<Cow<'static, str>>,
/// Where did the error occur?
pos: Pos,
/// Was this caused by another error?
source: Option<NetdocErrorSource>,
}
impl PartialEq for Error {
fn eq(&self, other: &Self) -> bool {
self.kind == other.kind && self.msg == other.msg && self.pos == other.pos
}
}
impl Error {
/// Helper: return this error's position.
pub(crate) fn pos(&self) -> Pos {
self.pos
}
/// Return a new error based on this one, with any byte-based
/// position mapped to some line within a string.
#[must_use]
pub fn within(mut self, s: &str) -> Error {
self.pos = self.pos.within(s);
self
}
/// Return a new error based on this one, with the position (if
/// any) replaced by 'p'.
#[must_use]
pub fn at_pos(mut self, p: Pos) -> Error {
self.pos = p;
self
}
/// Return a new error based on this one, with the position (if
/// replaced by 'p' if it had no position before.
#[must_use]
pub fn or_at_pos(mut self, p: Pos) -> Error {
match self.pos {
Pos::None | Pos::Unknown => {
self.pos = p;
}
_ => (),
}
self
}
/// Return a new error based on this one, with the message
/// value set to a provided static string.
#[must_use]
pub(crate) fn with_msg<T>(mut self, message: T) -> Error
where
T: Into<Cow<'static, str>>,
{
self.msg = Some(message.into());
self
}
/// Return a new error based on this one, with the source-error
/// value set to the provided error.
#[must_use]
pub(crate) fn with_source<T>(mut self, source: T) -> Error
where
T: Into<NetdocErrorSource>,
{
self.source = Some(source.into());
self
}
/// Return the [`NetdocErrorKind`] of this error.
pub fn netdoc_error_kind(&self) -> NetdocErrorKind {
self.kind
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}{}", self.kind, self.pos)?;
if let Some(msg) = &self.msg {
write!(f, ": {}", msg)?;
}
Ok(())
}
}
impl std::error::Error for Error {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
self.source.as_ref().map(|s| s as _)
}
}
/// Helper: declare an Into<> implementation to automatically convert a $source
/// into an Error with kind $kind.
macro_rules! declare_into {
{$source:ty => $kind:ident} => {
impl From<$source> for Error {
fn from(source: $source) -> Error {
Error {
kind: NetdocErrorKind::$kind,
msg: None,
pos: Pos::Unknown,
source: Some(source.into())
}
}
}
}
}
declare_into! { signature::Error => BadSignature }
declare_into! { tor_checkable::TimeValidityError => BadTimeBound }
declare_into! { tor_bytes::Error => Undecodable }
declare_into! { std::num::ParseIntError => BadArgument }
declare_into! { std::net::AddrParseError => BadArgument }
declare_into! { PolicyError => BadPolicy }
impl From<tor_error::Bug> for Error {
fn from(err: tor_error::Bug) -> Self {
use tor_error::HasKind;
let kind = match err.kind() {
tor_error::ErrorKind::BadApiUsage => NetdocErrorKind::BadApiUsage,
_ => NetdocErrorKind::Internal,
};
Error {
kind,
msg: None,
pos: Pos::Unknown,
source: Some(err.into()),
}
}
}
/// An error that occurs while trying to construct a network document.
#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum BuildError {
/// We were unable to build the document, probably due to an invalid
/// argument of some kind.
#[error("cannot build document: {0}")]
CannotBuild(&'static str),
/// An argument that was given as a string turned out to be unparsable.
#[error("unable to parse argument")]
Parse(#[from] crate::err::Error),
}