proxmox-installer-common/src/utils.rs

   1 use std::{
   2     fmt,
   3     net::{AddrParseError, IpAddr},
   4     num::ParseIntError,
   5     str::FromStr,
   6 };
   7
   8 use serde::Deserialize;
   9
  10 /// Possible errors that might occur when parsing CIDR addresses.
  11 #[derive(Debug)]
  12 pub enum CidrAddressParseError {
  13     /// No delimiter for separating address and mask was found.
  14     NoDelimiter,
  15     /// The IP address part could not be parsed.
  16     InvalidAddr(AddrParseError),
  17     /// The mask could not be parsed.
  18     InvalidMask(Option<ParseIntError>),
  19 }
  20
  21 /// An IP address (IPv4 or IPv6), including network mask.
  22 ///
  23 /// See the [`IpAddr`] type for more information how IP addresses are handled.
  24 /// The mask is appropriately enforced to be `0 <= mask <= 32` for IPv4 or
  25 /// `0 <= mask <= 128` for IPv6 addresses.
  26 ///
  27 /// # Examples
  28 /// ```
  29 /// use std::net::{Ipv4Addr, Ipv6Addr};
  30 /// use proxmox_installer_common::utils::CidrAddress;
  31 /// let ipv4 = CidrAddress::new(Ipv4Addr::new(192, 168, 0, 1), 24).unwrap();
  32 /// let ipv6 = CidrAddress::new(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0xc0a8, 1), 32).unwrap();
  33 ///
  34 /// assert_eq!(ipv4.to_string(), "192.168.0.1/24");
  35 /// assert_eq!(ipv6.to_string(), "2001:db8::c0a8:1/32");
  36 /// ```
  37 #[derive(Clone, Debug, PartialEq)]
  38 pub struct CidrAddress {
  39     addr: IpAddr,
  40     mask: usize,
  41 }
  42
  43 impl CidrAddress {
  44     /// Constructs a new CIDR address.
  45     ///
  46     /// It fails if the mask is invalid for the given IP address.
  47     pub fn new<T: Into<IpAddr>>(addr: T, mask: usize) -> Result<Self, CidrAddressParseError> {
  48         let addr = addr.into();
  49
  50         if mask > mask_limit(&addr) {
  51             Err(CidrAddressParseError::InvalidMask(None))
  52         } else {
  53             Ok(Self { addr, mask })
  54         }
  55     }
  56
  57     /// Returns only the IP address part of the address.
  58     pub fn addr(&self) -> IpAddr {
  59         self.addr
  60     }
  61
  62     /// Returns `true` if this address is an IPv4 address, `false` otherwise.
  63     pub fn is_ipv4(&self) -> bool {
  64         self.addr.is_ipv4()
  65     }
  66
  67     /// Returns `true` if this address is an IPv6 address, `false` otherwise.
  68     pub fn is_ipv6(&self) -> bool {
  69         self.addr.is_ipv6()
  70     }
  71
  72     /// Returns only the mask part of the address.
  73     pub fn mask(&self) -> usize {
  74         self.mask
  75     }
  76 }
  77
  78 impl FromStr for CidrAddress {
  79     type Err = CidrAddressParseError;
  80
  81     fn from_str(s: &str) -> Result<Self, Self::Err> {
  82         let (addr, mask) = s
  83             .split_once('/')
  84             .ok_or(CidrAddressParseError::NoDelimiter)?;
  85
  86         let addr = addr.parse().map_err(CidrAddressParseError::InvalidAddr)?;
  87
  88         let mask = mask
  89             .parse()
  90             .map_err(|err| CidrAddressParseError::InvalidMask(Some(err)))?;
  91
  92         if mask > mask_limit(&addr) {
  93             Err(CidrAddressParseError::InvalidMask(None))
  94         } else {
  95             Ok(Self { addr, mask })
  96         }
  97     }
  98 }
  99
 100 impl fmt::Display for CidrAddress {
 101     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 102         write!(f, "{}/{}", self.addr, self.mask)
 103     }
 104 }
 105
 106 fn mask_limit(addr: &IpAddr) -> usize {
 107     if addr.is_ipv4() {
 108         32
 109     } else {
 110         128
 111     }
 112 }
 113
 114 /// Possible errors that might occur when parsing FQDNs.
 115 #[derive(Debug, Eq, PartialEq)]
 116 pub enum FqdnParseError {
 117     MissingHostname,
 118     NumericHostname,
 119     InvalidPart(String),
 120     TooLong(usize),
 121 }
 122
 123 impl fmt::Display for FqdnParseError {
 124     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 125         use FqdnParseError::*;
 126         match self {
 127             MissingHostname => write!(f, "missing hostname part"),
 128             NumericHostname => write!(f, "hostname cannot be purely numeric"),
 129             InvalidPart(part) => write!(
 130                 f,
 131                 "FQDN must only consist of alphanumeric characters and dashes. Invalid part: '{part}'",
 132             ),
 133             TooLong(len) => write!(f, "FQDN too long: {len} > {}", Fqdn::MAX_LENGTH),
 134         }
 135     }
 136 }
 137
 138 /// A type for safely representing fully-qualified domain names (FQDNs).
 139 ///
 140 /// It considers following RFCs:
 141 /// https://www.ietf.org/rfc/rfc952.txt (sec. "ASSUMPTIONS", 1.)
 142 /// https://www.ietf.org/rfc/rfc1035.txt (sec. 2.3. "Conventions")
 143 /// https://www.ietf.org/rfc/rfc1123.txt (sec. 2.1. "Host Names and Numbers")
 144 /// https://www.ietf.org/rfc/rfc3492.txt
 145 /// https://www.ietf.org/rfc/rfc4343.txt
 146 ///
 147 /// .. and applies some restriction given by Debian, e.g. 253 instead of 255
 148 /// maximum total length and maximum 63 characters per label.
 149 /// https://manpages.debian.org/stable/manpages/hostname.7.en.html
 150 ///
 151 /// Additionally:
 152 /// - It enforces the restriction as per Bugzilla #1054, in that
 153 ///   purely numeric hostnames are not allowed - against RFC1123 sec. 2.1.
 154 ///
 155 /// Some terminology:
 156 /// - "label" - a single part of a FQDN, e.g. <label>.<label>.<tld>
 157 #[derive(Clone, Debug, Eq)]
 158 pub struct Fqdn {
 159     parts: Vec<String>,
 160 }
 161
 162 impl Fqdn {
 163     /// Maximum length of a single label of the FQDN
 164     const MAX_LABEL_LENGTH: usize = 63;
 165     /// Maximum total length of the FQDN
 166     const MAX_LENGTH: usize = 253;
 167
 168     pub fn from(fqdn: &str) -> Result<Self, FqdnParseError> {
 169         if fqdn.len() > Self::MAX_LENGTH {
 170             return Err(FqdnParseError::TooLong(fqdn.len()));
 171         }
 172
 173         let parts = fqdn
 174             .split('.')
 175             .map(ToOwned::to_owned)
 176             .collect::<Vec<String>>();
 177
 178         for part in &parts {
 179             if !Self::validate_single(part) {
 180                 return Err(FqdnParseError::InvalidPart(part.clone()));
 181             }
 182         }
 183
 184         if parts.len() < 2 {
 185             Err(FqdnParseError::MissingHostname)
 186         } else if parts[0].chars().all(|c| c.is_ascii_digit()) {
 187             // Do not allow a purely numeric hostname, see:
 188             // https://bugzilla.proxmox.com/show_bug.cgi?id=1054
 189             Err(FqdnParseError::NumericHostname)
 190         } else {
 191             Ok(Self { parts })
 192         }
 193     }
 194
 195     pub fn host(&self) -> Option<&str> {
 196         self.has_host().then_some(&self.parts[0])
 197     }
 198
 199     pub fn domain(&self) -> String {
 200         let parts = if self.has_host() {
 201             &self.parts[1..]
 202         } else {
 203             &self.parts
 204         };
 205
 206         parts.join(".")
 207     }
 208
 209     /// Checks whether the FQDN has a hostname associated with it, i.e. is has more than 1 part.
 210     fn has_host(&self) -> bool {
 211         self.parts.len() > 1
 212     }
 213
 214     fn validate_single(s: &String) -> bool {
 215         !s.is_empty()
 216             && s.len() <= Self::MAX_LABEL_LENGTH
 217             // First character must be alphanumeric
 218             && s.chars()
 219                 .next()
 220                 .map(|c| c.is_ascii_alphanumeric())
 221                 .unwrap_or_default()
 222             // .. last character as well,
 223             && s.chars()
 224                 .last()
 225                 .map(|c| c.is_ascii_alphanumeric())
 226                 .unwrap_or_default()
 227             // and anything between must be alphanumeric or -
 228             && s.chars()
 229                 .skip(1)
 230                 .take(s.len().saturating_sub(2))
 231                 .all(|c| c.is_ascii_alphanumeric() || c == '-')
 232     }
 233 }
 234
 235 impl FromStr for Fqdn {
 236     type Err = FqdnParseError;
 237
 238     fn from_str(value: &str) -> Result<Self, Self::Err> {
 239         Self::from(value)
 240     }
 241 }
 242
 243 impl fmt::Display for Fqdn {
 244     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 245         write!(f, "{}", self.parts.join("."))
 246     }
 247 }
 248
 249 impl<'de> Deserialize<'de> for Fqdn {
 250     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
 251     where
 252         D: serde::Deserializer<'de>,
 253     {
 254         let s: String = Deserialize::deserialize(deserializer)?;
 255         s.parse()
 256             .map_err(|_| serde::de::Error::custom("invalid FQDN"))
 257     }
 258 }
 259
 260 impl PartialEq for Fqdn {
 261     fn eq(&self, other: &Self) -> bool {
 262         // Case-insensitive comparison, as per RFC 952 "ASSUMPTIONS",
 263         // RFC 1035 sec. 2.3.3. "Character Case" and RFC 4343 as a whole
 264         let a = self
 265             .parts
 266             .iter()
 267             .map(|s| s.to_lowercase())
 268             .collect::<Vec<String>>();
 269
 270         let b = other
 271             .parts
 272             .iter()
 273             .map(|s| s.to_lowercase())
 274             .collect::<Vec<String>>();
 275
 276         a == b
 277     }
 278 }
 279
 280 #[cfg(test)]
 281 mod tests {
 282     use super::*;
 283
 284     #[test]
 285     fn fqdn_construct() {
 286         use FqdnParseError::*;
 287         assert!(Fqdn::from("foo.example.com").is_ok());
 288         assert!(Fqdn::from("foo-bar.com").is_ok());
 289         assert!(Fqdn::from("a-b.com").is_ok());
 290
 291         assert_eq!(Fqdn::from("foo"), Err(MissingHostname));
 292
 293         assert_eq!(Fqdn::from("-foo.com"), Err(InvalidPart("-foo".to_owned())));
 294         assert_eq!(Fqdn::from("foo-.com"), Err(InvalidPart("foo-".to_owned())));
 295         assert_eq!(Fqdn::from("foo.com-"), Err(InvalidPart("com-".to_owned())));
 296         assert_eq!(Fqdn::from("-o-.com"), Err(InvalidPart("-o-".to_owned())));
 297
 298         // https://bugzilla.proxmox.com/show_bug.cgi?id=1054
 299         assert_eq!(Fqdn::from("123.com"), Err(NumericHostname));
 300         assert!(Fqdn::from("foo123.com").is_ok());
 301         assert!(Fqdn::from("123foo.com").is_ok());
 302
 303         assert!(Fqdn::from(&format!("{}.com", "a".repeat(63))).is_ok());
 304         assert_eq!(
 305             Fqdn::from(&format!("{}.com", "a".repeat(250))),
 306             Err(TooLong(254)),
 307         );
 308         assert_eq!(
 309             Fqdn::from(&format!("{}.com", "a".repeat(64))),
 310             Err(InvalidPart("a".repeat(64))),
 311         );
 312
 313         // https://bugzilla.proxmox.com/show_bug.cgi?id=5230
 314         assert_eq!(
 315             Fqdn::from("123@foo.com"),
 316             Err(InvalidPart("123@foo".to_owned()))
 317         );
 318     }
 319
 320     #[test]
 321     fn fqdn_parts() {
 322         let fqdn = Fqdn::from("pve.example.com").unwrap();
 323         assert_eq!(fqdn.host().unwrap(), "pve");
 324         assert_eq!(fqdn.domain(), "example.com");
 325         assert_eq!(
 326             fqdn.parts,
 327             &["pve".to_owned(), "example".to_owned(), "com".to_owned()]
 328         );
 329     }
 330
 331     #[test]
 332     fn fqdn_display() {
 333         assert_eq!(
 334             Fqdn::from("foo.example.com").unwrap().to_string(),
 335             "foo.example.com"
 336         );
 337     }
 338
 339     #[test]
 340     fn fqdn_compare() {
 341         assert_eq!(Fqdn::from("example.com"), Fqdn::from("ExAmPle.Com"));
 342         assert_eq!(Fqdn::from("ExAmPle.Com"), Fqdn::from("example.com"));
 343     }
 344 }