fix(uri): prevent panic on clone if URI components are empty

libcoap/src/types.rs

@@ -9,20 +9,20 @@
 
 //! Types required for conversion between libcoap C library abstractions and Rust types.
 
+use std::ffi::CString;
+use std::fmt::{Display, Formatter};
+use std::marker::PhantomPinned;
+use std::ops::{Deref, DerefMut};
+use std::pin::Pin;
 use std::{
  fmt::Debug,
  mem::MaybeUninit,
  net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6, ToSocketAddrs},
  os::raw::c_int,
  str::FromStr,
 };
-use std::ffi::CString;
-use std::fmt::{Display, Formatter};
-use std::marker::PhantomPinned;
-use std::ops::{Deref, DerefMut};
-use std::pin::Pin;
 
-use libc::{AF_INET, AF_INET6, c_ushort, in6_addr, in_addr, sa_family_t, sockaddr_in, sockaddr_in6, socklen_t};
+use libc::{c_ushort, in6_addr, in_addr, sa_family_t, sockaddr_in, sockaddr_in6, socklen_t, AF_INET, AF_INET6};
 use num_derive::FromPrimitive;
 use num_traits::FromPrimitive;
 #[cfg(feature = "url")]
@@ -694,13 +694,31 @@ impl CoapUri {
  pub unsafe fn from_raw_uri(raw_uri: *const coap_uri_t, is_proxy: bool) -> CoapUri {
  // Loosely based on coap_clone_uri.
  assert!(!raw_uri.is_null());
+ let host_slice = (*raw_uri)
+ .host
+ .s
+ .is_null()
+ .then_some(&[] as &[u8])
+ .unwrap_or_else(|| std::slice::from_raw_parts((*raw_uri).host.s, (*raw_uri).host.length));
+ let path_slice = (*raw_uri)
+ .path
+ .s
+ .is_null()
+ .then_some(&[] as &[u8])
+ .unwrap_or_else(|| std::slice::from_raw_parts((*raw_uri).path.s, (*raw_uri).path.length));
+ let query_slice = (*raw_uri)
+ .query
+ .s
+ .is_null()
+ .then_some(&[] as &[u8])
+ .unwrap_or_else(|| std::slice::from_raw_parts((*raw_uri).query.s, (*raw_uri).query.length));
  // Clone the actual URI string.
  let (uri_str_copy, host_pos, path_pos, query_pos) = Self::construct_uri_string_from_parts(
  CoapUriScheme::from_raw_scheme((*raw_uri).scheme),
- std::slice::from_raw_parts((*raw_uri).host.s, (*raw_uri).host.length),
+ host_slice,
  (*raw_uri).port,
- std::slice::from_raw_parts((*raw_uri).path.s, (*raw_uri).path.length),
- std::slice::from_raw_parts((*raw_uri).query.s, (*raw_uri).query.length),
+ path_slice,
+ query_slice,
  )
  .expect("provided raw URI is invalid");