uucore::utmpx: refine implementation

src/uucore/utmpx.rs

@@ -1,125 +1,87 @@
-#![allow(dead_code, non_camel_case_types)]
+//! Aim to provide platform-independent methods to obtain login records
+//!
+//! **ONLY** support linux, macos and freebsd for the time being
 
-extern crate libc;
+use super::libc;
+pub extern crate time;
+use self::time::{Tm, Timespec};
 
-pub use self::utmpx::{UT_NAMESIZE, UT_LINESIZE, DEFAULT_FILE, USER_PROCESS, BOOT_TIME};
+use ::std::io::Result as IOResult;
-pub use self::utmpx::c_utmp;
+use ::std::io::Error as IOError;
-
+use ::std::ptr;
-extern "C" {
+use ::std::borrow::Cow;
-    pub fn getutxent() -> *const c_utmp;
+use ::std::ffi::CStr;
-    pub fn getutxid(ut: *const c_utmp) -> *const c_utmp;
+use ::std::ffi::CString;
-    pub fn getutxline(ut: *const c_utmp) -> *const c_utmp;
-    pub fn pututxline(ut: *const c_utmp) -> *const c_utmp;
-    pub fn setutxent();
-    pub fn endutxent();
-
-    #[cfg(any(target_os = "macos", target_os = "linux"))]
-    pub fn utmpxname(file: *const libc::c_char) -> libc::c_int;
-}
 
+pub use self::ut::*;
+use libc::utmpx;
+// pub use libc::getutxid;
+// pub use libc::getutxline;
+// pub use libc::pututxline;
+pub use libc::getutxent;
+pub use libc::setutxent;
+pub use libc::endutxent;
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+pub use libc::utmpxname;
 #[cfg(target_os = "freebsd")]
-pub unsafe extern fn utmpxname(_file: *const libc::c_char) -> libc::c_int {
+pub unsafe extern "C" fn utmpxname(_file: *const libc::c_char) -> libc::c_int {
     0
 }
 
-#[cfg(target_os = "linux")]
+macro_rules! bytes2cow {
-mod utmpx {
+    ($name:expr) => (
-    use super::libc;
+        unsafe {
+            CStr::from_ptr($name.as_ref().as_ptr()).to_string_lossy()
+        }
+    )
+}
 
+#[cfg(target_os = "linux")]
+mod ut {
     pub static DEFAULT_FILE: &'static str = "/var/run/utmp";
 
-    pub const UT_LINESIZE: usize = 32;
+    pub use libc::__UT_LINESIZE as UT_LINESIZE;
-    pub const UT_NAMESIZE: usize = 32;
+    pub use libc::__UT_NAMESIZE as UT_NAMESIZE;
+    pub use libc::__UT_HOSTSIZE as UT_HOSTSIZE;
     pub const UT_IDSIZE: usize = 4;
-    pub const UT_HOSTSIZE: usize = 256;
 
-    pub const EMPTY: libc::c_short = 0;
+    pub use libc::EMPTY;
-    pub const RUN_LVL: libc::c_short = 1;
+    pub use libc::RUN_LVL;
-    pub const BOOT_TIME: libc::c_short = 2;
+    pub use libc::BOOT_TIME;
-    pub const NEW_TIME: libc::c_short = 3;
+    pub use libc::NEW_TIME;
-    pub const OLD_TIME: libc::c_short = 4;
+    pub use libc::OLD_TIME;
-    pub const INIT_PROCESS: libc::c_short = 5;
+    pub use libc::INIT_PROCESS;
-    pub const LOGIN_PROCESS: libc::c_short = 6;
+    pub use libc::LOGIN_PROCESS;
-    pub const USER_PROCESS: libc::c_short = 7;
+    pub use libc::USER_PROCESS;
-    pub const DEAD_PROCESS: libc::c_short = 8;
+    pub use libc::DEAD_PROCESS;
-    pub const ACCOUNTING: libc::c_short = 9;
+    pub use libc::ACCOUNTING;
-
-    #[repr(C)]
-    pub struct __exit_status {
-        pub e_termination: libc::c_short,
-        pub e_exit: libc::c_short,
-    }
-
-    #[repr(C)]
-    #[derive(Copy, Clone)]
-    pub struct __timeval {
-        pub tv_sec: libc::int32_t,
-        pub tv_usec: libc::int32_t,
-    }
-
-    #[repr(C)]
-    pub struct c_utmp {
-        pub ut_type: libc::c_short,
-        pub ut_pid: libc::pid_t,
-        pub ut_line: [libc::c_char; UT_LINESIZE],
-        pub ut_id: [libc::c_char; UT_IDSIZE],
-
-        pub ut_user: [libc::c_char; UT_NAMESIZE],
-        pub ut_host: [libc::c_char; UT_HOSTSIZE],
-        pub ut_exit: __exit_status,
-
-        #[cfg(target_pointer_width = "32")]
-        pub ut_session: libc::c_long,
-        #[cfg(target_pointer_width = "32")]
-        pub ut_tv: libc::timeval,
-
-        #[cfg(target_pointer_width = "64")]
-        pub ut_session: libc::int32_t,
-        #[cfg(target_pointer_width = "64")]
-        pub ut_tv: __timeval,
-
-        pub ut_addr_v6: [libc::int32_t; 4],
-        __glibc_reserved: [libc::c_char; 20],
-    }
 }
 
 #[cfg(target_os = "macos")]
-mod utmpx {
+mod ut {
-    use super::libc;
-
     pub static DEFAULT_FILE: &'static str = "/var/run/utmpx";
 
-    pub const UT_LINESIZE: usize = 32;
+    pub use libc::_UTX_LINESIZE as UT_LINESIZE;
-    pub const UT_NAMESIZE: usize = 256;
+    pub use libc::_UTX_USERSIZE as UT_NAMESIZE;
-    pub const UT_IDSIZE: usize = 4;
+    pub use libc::_UTX_HOSTSIZE as UT_HOSTSIZE;
-    pub const UT_HOSTSIZE: usize = 256;
+    pub use libc::_UTX_IDSIZE as UT_IDSIZE;
 
-    pub const EMPTY: libc::c_short = 0;
+    pub use libc::EMPTY;
-    pub const RUN_LVL: libc::c_short = 1;
+    pub use libc::RUN_LVL;
-    pub const BOOT_TIME: libc::c_short = 2;
+    pub use libc::BOOT_TIME;
-    pub const OLD_TIME: libc::c_short = 3;
+    pub use libc::NEW_TIME;
-    pub const NEW_TIME: libc::c_short = 4;
+    pub use libc::OLD_TIME;
-    pub const INIT_PROCESS: libc::c_short = 5;
+    pub use libc::INIT_PROCESS;
-    pub const LOGIN_PROCESS: libc::c_short = 6;
+    pub use libc::LOGIN_PROCESS;
-    pub const USER_PROCESS: libc::c_short = 7;
+    pub use libc::USER_PROCESS;
-    pub const DEAD_PROCESS: libc::c_short = 8;
+    pub use libc::DEAD_PROCESS;
-    pub const ACCOUNTING: libc::c_short = 9;
+    pub use libc::ACCOUNTING;
-
+    pub use libc::SIGNATURE;
-    #[repr(C)]
+    pub use libc::SHUTDOWN_TIME;
-    pub struct c_utmp {
-        pub ut_user: [libc::c_char; UT_NAMESIZE],
-        pub ut_id: [libc::c_char; UT_IDSIZE],
-        pub ut_line: [libc::c_char; UT_LINESIZE],
-        pub ut_pid: libc::pid_t,
-        pub ut_type: libc::c_short,
-        pub ut_tv: libc::timeval,
-        pub ut_host: [libc::c_char; UT_HOSTSIZE],
-        pub __unused: [libc::uint32_t; 16],
-    }
 }
 
 #[cfg(target_os = "freebsd")]
-mod utmpx {
+mod ut {
     use super::libc;
 
     pub static DEFAULT_FILE: &'static str = "";
@@ -129,25 +91,158 @@ mod utmpx {
     pub const UT_IDSIZE: usize = 8;
     pub const UT_HOSTSIZE: usize = 128;
 
-    pub const EMPTY: libc::c_short = 0;
+    pub use libc::EMPTY;
-    pub const BOOT_TIME: libc::c_short = 1;
+    pub use libc::BOOT_TIME;
-    pub const OLD_TIME: libc::c_short = 2;
+    pub use libc::OLD_TIME;
-    pub const NEW_TIME: libc::c_short = 3;
+    pub use libc::NEW_TIME;
-    pub const USER_PROCESS: libc::c_short = 4;
+    pub use libc::USER_PROCESS;
-    pub const INIT_PROCESS: libc::c_short = 5;
+    pub use libc::INIT_PROCESS;
-    pub const LOGIN_PROCESS: libc::c_short = 6;
+    pub use libc::LOGIN_PROCESS;
-    pub const DEAD_PROCESS: libc::c_short = 7;
+    pub use libc::DEAD_PROCESS;
-    pub const SHUTDOWN_TIME: libc::c_short = 8;
+    pub use libc::SHUTDOWN_TIME;
+}
 
-    #[repr(C)]
+/// Login records
-    pub struct c_utmp {
+///
-        pub ut_type: libc::c_short,
+/// Examples:
-        pub ut_tv: libc::timeval,
+/// ---------
-        pub ut_id: [libc::c_char; UT_IDSIZE],
+///
-        pub ut_pid: libc::pid_t,
+/// ```
-        pub ut_user: [libc::c_char; UT_NAMESIZE],
+/// for ut in Utmpx::iter_all_records() {
-        pub ut_line: [libc::c_char; UT_LINESIZE],
+///     if ut.is_user_process() {
-        pub ut_host: [libc::c_char; UT_HOSTSIZE],
+///         println!("{}: {}", ut.host(), ut.user())
-        pub ut_spare: [libc::c_char; 64],
+///     }
+/// }
+/// ```
+///
+/// Specifying the path to login record:
+///
+/// ```
+/// for ut in Utmpx::iter_all_records().read_from("/some/where/else") {
+///     if ut.is_user_process() {
+///         println!("{}: {}", ut.host(), ut.user())
+///     }
+/// }
+/// ```
+pub struct Utmpx {
+    inner: utmpx,
+}
+
+impl Utmpx {
+    /// A.K.A. ut.ut_type
+    pub fn record_type(&self) -> i16 {
+        self.inner.ut_type as i16
+    }
+    /// A.K.A. ut.ut_pid
+    pub fn pid(&self) -> i32 {
+        self.inner.ut_pid as i32
+    }
+    /// A.K.A. ut.ut_id
+    pub fn terminal_suffix(&self) -> Cow<str> {
+        bytes2cow!(self.inner.ut_id)
+    }
+    /// A.K.A. ut.ut_user
+    pub fn user(&self) -> Cow<str> {
+        bytes2cow!(self.inner.ut_user)
+    }
+    /// A.K.A. ut.ut_host
+    pub fn host(&self) -> Cow<str> {
+        bytes2cow!(self.inner.ut_host)
+    }
+    /// A.K.A. ut.ut_line
+    pub fn tty_device(&self) -> Cow<str> {
+        bytes2cow!(self.inner.ut_line)
+    }
+    /// A.K.A. ut.ut_tv
+    pub fn login_time(&self) -> Tm {
+        time::at(Timespec::new(self.inner.ut_tv.tv_sec as i64,
+                               self.inner.ut_tv.tv_usec as i32))
+    }
+    /// Consumes the `Utmpx`, returning the underlying C struct utmpx
+    pub fn into_inner(self) -> utmpx {
+        self.inner
+    }
+    pub fn is_user_process(&self) -> bool {
+        !self.user().is_empty() && self.record_type() == USER_PROCESS
+    }
+
+    /// Canonicalize host name using DNS
+    pub fn canon_host(&self) -> IOResult<String> {
+        const AI_CANONNAME: libc::c_int = 0x2;
+        let host = self.host();
+        let hints = libc::addrinfo {
+            ai_flags: AI_CANONNAME,
+            ai_family: 0,
+            ai_socktype: 0,
+            ai_protocol: 0,
+            ai_addrlen: 0,
+            ai_addr: ptr::null_mut(),
+            ai_canonname: ptr::null_mut(),
+            ai_next: ptr::null_mut(),
+        };
+        let c_host = CString::new(host.as_ref()).unwrap();
+        let mut res = ptr::null_mut();
+        let status = unsafe {
+            libc::getaddrinfo(c_host.as_ptr(),
+                              ptr::null(),
+                              &hints as *const _,
+                              &mut res as *mut _)
+        };
+        if status == 0 {
+            let info: libc::addrinfo = unsafe { ptr::read(res as *const _) };
+            // http://lists.gnu.org/archive/html/bug-coreutils/2006-09/msg00300.html
+            // says Darwin 7.9.0 getaddrinfo returns 0 but sets
+            // res->ai_canonname to NULL.
+            let ret = if info.ai_canonname.is_null() {
+                Ok(String::from(host.as_ref()))
+            } else {
+                Ok(unsafe { CString::from_raw(info.ai_canonname).into_string().unwrap() })
+            };
+            unsafe {
+                libc::freeaddrinfo(res);
+            }
+            ret
+        } else {
+            Err(IOError::last_os_error())
+        }
+    }
+    pub fn iter_all_records() -> UtmpxIter {
+        UtmpxIter
+    }
+}
+
+/// Iterator of login records
+pub struct UtmpxIter;
+
+impl UtmpxIter {
+    /// Sets the name of the utmpx-format file for the other utmpx functions to access.
+    ///
+    /// If not set, default record file will be used(file path depends on the target OS)
+    pub fn read_from(self, f: &str) -> Self {
+        let res = unsafe { utmpxname(CString::new(f).unwrap().as_ptr()) };
+        if res != 0 {
+            println!("Warning: {}", IOError::last_os_error());
+        }
+        unsafe {
+            setutxent();
+        }
+        self
+    }
+}
+
+impl Iterator for UtmpxIter {
+    type Item = Utmpx;
+    fn next(&mut self) -> Option<Self::Item> {
+        unsafe {
+            let res = getutxent();
+            if !res.is_null() {
+                Some(Utmpx {
+                    inner: ptr::read(res as *const _)
+                })
+            } else {
+                endutxent();
+                None
+            }
+        }
     }
 }