Better error reporting

This commit is contained in:
topjohnwu 2024-03-21 15:10:34 -07:00
parent dd9d43be96
commit 0ffc4527a7

View File

@ -36,8 +36,7 @@ pub enum Token<'a> {
}
type Tokens<'a> = Peekable<IntoIter<Token<'a>>>;
type SimpleResult<T> = Result<T, ()>;
type ParseResult<'a> = Result<(), ParseError<'a>>;
type ParseResult<'a, T> = Result<T, ParseError<'a>>;
enum ParseError<'a> {
General,
@ -50,15 +49,17 @@ enum ParseError<'a> {
NewType,
NewAttr,
GenfsCon,
ShowHelp,
UnknownAction(Token<'a>),
}
macro_rules! throw {
() => {
Err(())?
Err(ParseError::General)?
};
}
fn parse_id<'a>(tokens: &mut Tokens<'a>) -> SimpleResult<&'a str> {
fn parse_id<'a>(tokens: &mut Tokens<'a>) -> ParseResult<'a, &'a str> {
match tokens.next() {
Some(Token::ID(name)) => Ok(name),
_ => throw!(),
@ -69,7 +70,7 @@ fn parse_id<'a>(tokens: &mut Tokens<'a>) -> SimpleResult<&'a str> {
// names ::= names(mut v) CM ID(n) { v.push(n); v };
// term ::= ID(n) { vec![n] }
// term ::= LB names(n) RB { n };
fn parse_term<'a>(tokens: &mut Tokens<'a>) -> SimpleResult<Vec<&'a str>> {
fn parse_term<'a>(tokens: &mut Tokens<'a>) -> ParseResult<'a, Vec<&'a str>> {
match tokens.next() {
Some(Token::ID(name)) => Ok(vec![name]),
Some(Token::LB) => {
@ -94,7 +95,7 @@ fn parse_term<'a>(tokens: &mut Tokens<'a>) -> SimpleResult<Vec<&'a str>> {
// terms ::= ST { vec![] }
// terms ::= term(n) { n }
fn parse_terms<'a>(tokens: &mut Tokens<'a>) -> SimpleResult<Vec<&'a str>> {
fn parse_terms<'a>(tokens: &mut Tokens<'a>) -> ParseResult<'a, Vec<&'a str>> {
match tokens.peek() {
Some(Token::ST) => {
tokens.next();
@ -106,7 +107,7 @@ fn parse_terms<'a>(tokens: &mut Tokens<'a>) -> SimpleResult<Vec<&'a str>> {
// xperm ::= HX(low) { Xperm{low, high: low, reset: false} };
// xperm ::= HX(low) HP HX(high) { Xperm{low, high, reset: false} };
fn parse_xperm(tokens: &mut Tokens) -> SimpleResult<Xperm> {
fn parse_xperm<'a>(tokens: &mut Tokens<'a>) -> ParseResult<'a, Xperm> {
let low = match tokens.next() {
Some(Token::HX(low)) => low,
_ => throw!(),
@ -135,7 +136,7 @@ fn parse_xperm(tokens: &mut Tokens) -> SimpleResult<Xperm> {
//
// xperm_list ::= xperm(p) { vec![p] }
// xperm_list ::= xperm_list(mut l) xperm(p) { l.push(p); l }
fn parse_xperms(tokens: &mut Tokens) -> SimpleResult<Vec<Xperm>> {
fn parse_xperms<'a>(tokens: &mut Tokens<'a>) -> ParseResult<'a, Vec<Xperm>> {
let mut xperms = Vec::new();
let reset = match tokens.peek() {
Some(Token::TL) => {
@ -205,18 +206,29 @@ fn parse_xperms(tokens: &mut Tokens) -> SimpleResult<Vec<Xperm>> {
// statement ::= TC ID(s) ID(t) ID(c) ID(d) { extra.as_mut().type_change(s, t, c, d); };
// statement ::= TM ID(s) ID(t) ID(c) ID(d) { extra.as_mut().type_member(s, t, c, d);};
// statement ::= GF ID(s) ID(t) ID(c) { extra.as_mut().genfscon(s, t, c); };
fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> ParseResult<'a> {
fn exec_statement<'a>(
sepolicy: Pin<&mut sepolicy>,
tokens: &mut Tokens<'a>,
) -> ParseResult<'a, ()> {
let action = match tokens.next() {
Some(token) => token,
_ => Err(ParseError::General)?,
_ => Err(ParseError::ShowHelp)?,
};
let check_additional_args = |tokens: &mut Tokens<'a>| {
if tokens.peek().is_none() {
Ok(())
} else {
Err(ParseError::General)
}
};
match action {
Token::AL | Token::DN | Token::AA | Token::DA => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let s = parse_terms(tokens)?;
let t = parse_terms(tokens)?;
let c = parse_terms(tokens)?;
let p = parse_terms(tokens)?;
check_additional_args(tokens)?;
match action {
Token::AL => sepolicy.allow(s, t, c, p),
Token::DN => sepolicy.deny(s, t, c, p),
@ -230,7 +242,7 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::AX | Token::AY | Token::DX => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let s = parse_terms(tokens)?;
let t = parse_terms(tokens)?;
let c = parse_terms(tokens)?;
@ -239,6 +251,7 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
} else {
throw!()
};
check_additional_args(tokens)?;
match action {
Token::AX => sepolicy.allowxperm(s, t, c, p),
Token::AY => sepolicy.auditallowxperm(s, t, c, p),
@ -251,8 +264,9 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::PM | Token::EF => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let t = parse_terms(tokens)?;
check_additional_args(tokens)?;
match action {
Token::PM => sepolicy.permissive(t),
Token::EF => sepolicy.enforce(t),
@ -264,9 +278,10 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::TA => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let t = parse_term(tokens)?;
let a = parse_term(tokens)?;
check_additional_args(tokens)?;
sepolicy.typeattribute(t, a)
};
if result.is_err() {
@ -274,13 +289,14 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::TY => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let t = parse_id(tokens)?;
let a = if tokens.peek().is_none() {
vec![]
} else {
parse_term(tokens)?
};
check_additional_args(tokens)?;
sepolicy.type_(t, a)
};
if result.is_err() {
@ -288,8 +304,9 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::AT => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let t = parse_id(tokens)?;
check_additional_args(tokens)?;
sepolicy.attribute(t)
};
if result.is_err() {
@ -297,11 +314,12 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::TC | Token::TM => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let s = parse_id(tokens)?;
let t = parse_id(tokens)?;
let c = parse_id(tokens)?;
let d = parse_id(tokens)?;
check_additional_args(tokens)?;
match action {
Token::TC => sepolicy.type_change(s, t, c, d),
Token::TM => sepolicy.type_member(s, t, c, d),
@ -313,7 +331,7 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::TT => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let s = parse_id(tokens)?;
let t = parse_id(tokens)?;
let c = parse_id(tokens)?;
@ -323,6 +341,7 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
} else {
parse_id(tokens)?
};
check_additional_args(tokens)?;
sepolicy.type_transition(s, t, c, d, o);
};
if result.is_err() {
@ -330,23 +349,20 @@ fn exec_statement<'a>(sepolicy: Pin<&mut sepolicy>, tokens: &'a mut Tokens) -> P
}
}
Token::GF => {
let result: SimpleResult<()> = try {
let result: ParseResult<()> = try {
let s = parse_id(tokens)?;
let t = parse_id(tokens)?;
let c = parse_id(tokens)?;
check_additional_args(tokens)?;
sepolicy.genfscon(s, t, c)
};
if result.is_err() {
Err(ParseError::GenfsCon)?
}
}
_ => Err(ParseError::General)?,
}
if tokens.peek().is_none() {
Ok(())
} else {
Err(ParseError::General)
_ => Err(ParseError::UnknownAction(action))?,
}
Ok(())
}
fn tokenize_statement(statement: &str) -> Vec<Token> {
@ -456,7 +472,8 @@ impl Display for Token<'_> {
impl Display for ParseError<'_> {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
match self {
ParseError::General => format_statement_help(f),
ParseError::General => Ok(()),
ParseError::ShowHelp => format_statement_help(f),
ParseError::AvtabAv(action) => {
write!(f, "{action} *source_type *target_type *class *perm_set")
}
@ -479,6 +496,7 @@ impl Display for ParseError<'_> {
ParseError::NewType => f.write_str("type type_name ^(attribute)"),
ParseError::NewAttr => f.write_str("attribute attribute_name"),
ParseError::GenfsCon => f.write_str("genfscon fs_name partial_path fs_context"),
ParseError::UnknownAction(action) => write!(f, "Unknown action: \"{action}\""),
}
}
}