use alloc::{str::FromStr, boxed::Box};
use core::fmt;
#[cfg(not(feature = "std"))]
use core::error::Error;
#[cfg(feature = "std")]
use std::error::Error;
#[cfg(not(feature = "std"))]
use core::net::{Ipv4Addr, Ipv6Addr};
#[cfg(feature = "std")]
use std::net::{Ipv4Addr, Ipv6Addr};
use crate::ipnet::{IpNet, Ipv4Net, Ipv6Net};
pub struct Parser<'a> {
s: &'a [u8],
pos: usize,
}
impl<'a> Parser<'a> {
fn new(s: &'a str) -> Parser<'a> {
Parser {
s: s.as_bytes(),
pos: 0,
}
}
fn is_eof(&self) -> bool {
self.pos == self.s.len()
}
fn read_atomically<T, F>(&mut self, cb: F) -> Option<T> where
F: FnOnce(&mut Parser) -> Option<T>,
{
let pos = self.pos;
let r = cb(self);
if r.is_none() {
self.pos = pos;
}
r
}
fn read_till_eof<T, F>(&mut self, cb: F) -> Option<T> where
F: FnOnce(&mut Parser) -> Option<T>,
{
self.read_atomically(move |p| {
match cb(p) {
Some(x) => if p.is_eof() {Some(x)} else {None},
None => None,
}
})
}
fn read_or<T>(&mut self, parsers: &mut [Box<dyn FnMut(&mut Parser) -> Option<T> + 'static>])
-> Option<T> {
for pf in parsers {
if let Some(r) = self.read_atomically(|p: &mut Parser| pf(p)) {
return Some(r);
}
}
None
}
fn read_seq_3<A, B, C, PA, PB, PC>(&mut self,
pa: PA,
pb: PB,
pc: PC)
-> Option<(A, B, C)> where
PA: FnOnce(&mut Parser) -> Option<A>,
PB: FnOnce(&mut Parser) -> Option<B>,
PC: FnOnce(&mut Parser) -> Option<C>,
{
self.read_atomically(move |p| {
let a = pa(p);
let b = if a.is_some() { pb(p) } else { None };
let c = if b.is_some() { pc(p) } else { None };
match (a, b, c) {
(Some(a), Some(b), Some(c)) => Some((a, b, c)),
_ => None
}
})
}
fn read_char(&mut self) -> Option<char> {
if self.is_eof() {
None
} else {
let r = self.s[self.pos] as char;
self.pos += 1;
Some(r)
}
}
fn read_given_char(&mut self, c: char) -> Option<char> {
self.read_atomically(|p| {
match p.read_char() {
Some(next) if next == c => Some(next),
_ => None,
}
})
}
fn read_digit(&mut self, radix: u8) -> Option<u8> {
fn parse_digit(c: char, radix: u8) -> Option<u8> {
let c = c as u8;
if c >= b'0' && c <= b'9' {
Some(c - b'0')
} else if radix > 10 && c >= b'a' && c < b'a' + (radix - 10) {
Some(c - b'a' + 10)
} else if radix > 10 && c >= b'A' && c < b'A' + (radix - 10) {
Some(c - b'A' + 10)
} else {
None
}
}
self.read_atomically(|p| {
p.read_char().and_then(|c| parse_digit(c, radix))
})
}
fn read_number_impl(&mut self, radix: u8, max_digits: u32, upto: u32) -> Option<u32> {
let mut r = 0;
let mut digit_count = 0;
loop {
match self.read_digit(radix) {
Some(d) => {
r = r * (radix as u32) + (d as u32);
digit_count += 1;
if digit_count > max_digits || r >= upto {
return None
}
}
None => {
if digit_count == 0 {
return None
} else {
return Some(r)
}
}
};
}
}
fn read_number(&mut self, radix: u8, max_digits: u32, upto: u32) -> Option<u32> {
self.read_atomically(|p| p.read_number_impl(radix, max_digits, upto))
}
fn read_ipv4_addr_impl(&mut self) -> Option<Ipv4Addr> {
let mut bs = [0; 4];
let mut i = 0;
while i < 4 {
if i != 0 && self.read_given_char('.').is_none() {
return None;
}
let octet = self.read_number(10, 3, 0x100).map(|n| n as u8);
match octet {
Some(d) => bs[i] = d,
None => return None,
};
i += 1;
}
Some(Ipv4Addr::new(bs[0], bs[1], bs[2], bs[3]))
}
fn read_ipv4_addr(&mut self) -> Option<Ipv4Addr> {
self.read_atomically(|p| p.read_ipv4_addr_impl())
}
fn read_ipv6_addr_impl(&mut self) -> Option<Ipv6Addr> {
fn ipv6_addr_from_head_tail(head: &[u16], tail: &[u16]) -> Ipv6Addr {
assert!(head.len() + tail.len() <= 8);
let mut gs = [0; 8];
gs[..head.len()].copy_from_slice(head);
gs[(8 - tail.len()) .. 8].copy_from_slice(tail);
Ipv6Addr::new(gs[0], gs[1], gs[2], gs[3], gs[4], gs[5], gs[6], gs[7])
}
fn read_groups(p: &mut Parser, groups: &mut [u16; 8], limit: usize)
-> (usize, bool) {
let mut i = 0;
while i < limit {
if i < limit - 1 {
let ipv4 = p.read_atomically(|p| {
if i == 0 || p.read_given_char(':').is_some() {
p.read_ipv4_addr()
} else {
None
}
});
if let Some(v4_addr) = ipv4 {
let octets = v4_addr.octets();
groups[i + 0] = ((octets[0] as u16) << 8) | (octets[1] as u16);
groups[i + 1] = ((octets[2] as u16) << 8) | (octets[3] as u16);
return (i + 2, true);
}
}
let group = p.read_atomically(|p| {
if i == 0 || p.read_given_char(':').is_some() {
p.read_number(16, 4, 0x10000).map(|n| n as u16)
} else {
None
}
});
match group {
Some(g) => groups[i] = g,
None => return (i, false)
}
i += 1;
}
(i, false)
}
let mut head = [0; 8];
let (head_size, head_ipv4) = read_groups(self, &mut head, 8);
if head_size == 8 {
return Some(Ipv6Addr::new(
head[0], head[1], head[2], head[3],
head[4], head[5], head[6], head[7]))
}
if head_ipv4 {
return None
}
if !self.read_given_char(':').is_some() || !self.read_given_char(':').is_some() {
return None;
}
let mut tail = [0; 8];
let (tail_size, _) = read_groups(self, &mut tail, 8 - head_size);
Some(ipv6_addr_from_head_tail(&head[..head_size], &tail[..tail_size]))
}
fn read_ipv6_addr(&mut self) -> Option<Ipv6Addr> {
self.read_atomically(|p| p.read_ipv6_addr_impl())
}
fn read_ipv4_net(&mut self) -> Option<Ipv4Net> {
let ip_addr = |p: &mut Parser| p.read_ipv4_addr();
let slash = |p: &mut Parser| p.read_given_char('/');
let prefix_len = |p: &mut Parser| {
p.read_number(10, 2, 33).map(|n| n as u8)
};
self.read_seq_3(ip_addr, slash, prefix_len).map(|t| {
let (ip, _, prefix_len): (Ipv4Addr, char, u8) = t;
Ipv4Net::new(ip, prefix_len).unwrap()
})
}
fn read_ipv6_net(&mut self) -> Option<Ipv6Net> {
let ip_addr = |p: &mut Parser| p.read_ipv6_addr();
let slash = |p: &mut Parser| p.read_given_char('/');
let prefix_len = |p: &mut Parser| {
p.read_number(10, 3, 129).map(|n| n as u8)
};
self.read_seq_3(ip_addr, slash, prefix_len).map(|t| {
let (ip, _, prefix_len): (Ipv6Addr, char, u8) = t;
Ipv6Net::new(ip, prefix_len).unwrap()
})
}
fn read_ip_net(&mut self) -> Option<IpNet> {
let ipv4_net = |p: &mut Parser| p.read_ipv4_net().map(IpNet::V4);
let ipv6_net = |p: &mut Parser| p.read_ipv6_net().map(IpNet::V6);
self.read_or(&mut [Box::new(ipv4_net), Box::new(ipv6_net)])
}
}
impl FromStr for IpNet {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<IpNet, AddrParseError> {
match Parser::new(s).read_till_eof(|p| p.read_ip_net()) {
Some(s) => Ok(s),
None => Err(AddrParseError(()))
}
}
}
impl FromStr for Ipv4Net {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<Ipv4Net, AddrParseError> {
match Parser::new(s).read_till_eof(|p| p.read_ipv4_net()) {
Some(s) => Ok(s),
None => Err(AddrParseError(()))
}
}
}
impl FromStr for Ipv6Net {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<Ipv6Net, AddrParseError> {
match Parser::new(s).read_till_eof(|p| p.read_ipv6_net()) {
Some(s) => Ok(s),
None => Err(AddrParseError(()))
}
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct AddrParseError(());
impl fmt::Display for AddrParseError {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.write_str("invalid IP address syntax")
}
}
impl Error for AddrParseError {}