On Tue Apr 1, 2025 at 3:21 PM CEST, Stefan Hanreich wrote: > Add a type for representing Linux hostnames. These are the same > constraints as the installer enforces [1].
Actually, the regex is not *fully* complete, see parse_fqdn() in the same file in [1]. [..] > [1] > https://git.proxmox.com/?p=pve-installer.git;a=blob;f=Proxmox/Sys/Net.pm;h=81cb15f0042b195461324fffeca53d732133629e;hb=HEAD#l11 > [..] > diff --git a/proxmox-network-types/src/hostname.rs > b/proxmox-network-types/src/hostname.rs > new file mode 100644 > index 00000000..f183aecb > --- /dev/null > +++ b/proxmox-network-types/src/hostname.rs [..] > +/// Hostname of a Linux machine > +/// > +/// A hostname is at most 63 characters long and must only contain lowercase > alphanumeric > +/// characters as well as hyphens. It must not start or end with a hyphen. This should probably also reject purely numeric hostnames, as mentioned in Bugzilla #1054 [0]. This isn't a requirement per any RFC, but seems to can cause subtle bugs. It's enforced in the installer too. [0] https://bugzilla.proxmox.com/show_bug.cgi?id=1054 > +#[derive(Debug, Deserialize, Serialize, Clone, Eq, Hash, PartialOrd, Ord, > PartialEq)] > +pub struct Hostname(String); > + [..] > + > +impl Hostname { > + /// Constructs a new hostname from a string > + /// > + /// This function accepts characters in any case, but the resulting > hostname will be > + /// lowercased. > + pub fn new(name: impl AsRef<str>) -> Result<Self, HostnameError> { > + let name_ref = name.as_ref(); > + > + if !(1..63).contains(&name_ref.len()) { This actually fails for hostnames exactly 63 characters long (which should be accepted), as `..` is non-inclusive :^) E.g. the following tests, adapted from proxmox-installer-common/utils.rs in pve-installer: #[cfg(test)] mod tests { use super::*; #[test] fn too_long() { assert!(Hostname::new(format!("{}.com", "a".repeat(63))).is_ok()); assert!(Hostname::new(format!("{}.com", "a".repeat(64))).is_err()); } } > + return Err(HostnameError::InvalidLength); > + } > + > + let host_name = name_ref.to_lowercase(); > + > + let mut characters = host_name.chars(); > + > + // first character must not be a hyphen > + // SAFETY: ok because of length check > + if !characters.next().unwrap().is_alphanumeric() { This should rather use .is_ascii_alphanumeric(). Otherwise any alphanumeric Unicode character is accepted [1], but hostnames may be ASCII only, as per e.g. RFC 952 ("ASSUMPTIONS") and hostname(7) [2]. [1] https://doc.rust-lang.org/std/primitive.char.html#method.is_alphabetic [2] https://manpages.debian.org/bookworm/manpages/hostname.7.en.html > + return Err(HostnameError::InvalidSymbols); > + } > + > + if !characters.all(|c| c.is_alphanumeric() || c == '-') { ^ same as above. > + return Err(HostnameError::InvalidSymbols); > + } > + > + // last character must not be a hyphen > + // SAFETY: ok because of length check > + if !host_name.chars().next_back().unwrap().is_alphanumeric() { ^ same as above. _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
