1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
//! Syslog
//!
//! This crate provides facilities to send log messages via syslog.
//! It supports Unix sockets for local syslog, UDP and TCP for remote servers.
//!
//! Messages can be passed directly without modification, or in RFC 3164 or RFC 5424 format
//!
//! The code is available on [Github](https://github.com/Geal/rust-syslog)
//!
//! # Example
//!
//! ```
//! extern crate syslog;
//!
//! use syslog::{Facility, Formatter3164};
//!
//! fn main() {
//!     let formatter = Formatter3164 {
//!         facility: Facility::LOG_USER,
//!         hostname: None,
//!         process: "myprogram".into(),
//!         pid: 0,
//!     };
//!
//!     match syslog::unix(formatter) {
//!         Err(e) => println!("impossible to connect to syslog: {:?}", e),
//!         Ok(mut writer) => {
//!             writer.err("hello world").expect("could not write error message");
//!         }
//!     }
//! }
//! ```
#![crate_type = "lib"]

#[macro_use] extern crate error_chain;
extern crate unix_socket;
extern crate libc;
extern crate time;
extern crate log;

use std::env;
use std::path::Path;
use std::fmt::{self,Arguments,Display};
use std::io::{self, BufWriter, Write};
use std::sync::{Arc,Mutex};
use std::marker::PhantomData;
use std::net::{SocketAddr,ToSocketAddrs,UdpSocket,TcpStream};

use libc::getpid;
use unix_socket::{UnixDatagram, UnixStream};
use log::{Log, Metadata, Record, Level};

mod facility;
mod format;
mod errors;
pub use facility::Facility;
pub use format::Severity;
pub use errors::*;

use format::{LogFormat};
pub use format::{Formatter3164, Formatter5424};

pub type Priority = u8;

/// Main logging structure
pub struct Logger<Backend: Write, T, Formatter: LogFormat<T>> {
  formatter: Formatter,
  backend:   Backend,
  phantom:   PhantomData<T>,
}

impl<W:Write, T, F:LogFormat<T>> Logger<W, T, F> {
  pub fn emerg(&mut self, message: T) -> Result<()> {
    self.formatter.emerg(&mut self.backend, message)
  }

  pub fn alert(&mut self, message: T) -> Result<()> {
    self.formatter.alert(&mut self.backend, message)
  }

  pub fn crit(&mut self, message: T) -> Result<()> {
    self.formatter.crit(&mut self.backend, message)
  }

  pub fn err(&mut self, message: T) -> Result<()> {
    self.formatter.err(&mut self.backend, message)
  }

  pub fn warning(&mut self, message: T) -> Result<()> {
    self.formatter.warning(&mut self.backend, message)
  }

  pub fn notice(&mut self, message: T) -> Result<()> {
    self.formatter.notice(&mut self.backend, message)
  }

  pub fn info(&mut self, message: T) -> Result<()> {
    self.formatter.info(&mut self.backend, message)
  }

  pub fn debug(&mut self, message: T) -> Result<()> {
    self.formatter.debug(&mut self.backend, message)
  }
}

pub enum LoggerBackend {
  /// Unix socket, temp file path, log file path
  Unix(UnixDatagram),
  UnixStream(BufWriter<UnixStream>),
  Udp(UdpSocket, SocketAddr),
  Tcp(BufWriter<TcpStream>)
}

impl Write for LoggerBackend {
  /// Sends a message directly, without any formatting
  fn write(&mut self, message: &[u8]) -> io::Result<usize> {
    match self {
      &mut LoggerBackend::Unix(ref dgram) => {
        dgram.send(&message[..])
      },
      &mut LoggerBackend::UnixStream(ref mut socket) => {
        let null = [0 ; 1];
        socket.write(&message[..]).and_then(|sz| {
          socket.write(&null).map(|_| sz)
        })
      },
      &mut LoggerBackend::Udp(ref socket, ref addr)    => {
        socket.send_to(&message[..], addr)
      },
      &mut LoggerBackend::Tcp(ref mut socket)         => {
        socket.write(&message[..])
      }
    }
  }

  fn write_fmt(&mut self, args: Arguments) -> io::Result<()>  {
    match self {
      &mut LoggerBackend::Unix(ref dgram) => {
        let message = fmt::format(args);
        dgram.send(message.as_bytes()).map(|_| ())
      },
      &mut LoggerBackend::UnixStream(ref mut socket) => {
        let null = [0 ; 1];
        socket.write_fmt(args).and_then(|_| {
          socket.write(&null).map(|_| ())
        })
      },
      &mut LoggerBackend::Udp(ref socket, ref addr)    => {
        let message = fmt::format(args);
        socket.send_to(message.as_bytes(), addr).map(|_| ())
      },
      &mut LoggerBackend::Tcp(ref mut socket)         => {
        socket.write_fmt(args)
      }
    }
  }

  fn flush(&mut self) -> io::Result<()> {
    match self {
      &mut LoggerBackend::Unix(_) => {
        Ok(())
      },
      &mut LoggerBackend::UnixStream(ref mut socket) => {
        socket.flush()
      },
      &mut LoggerBackend::Udp(_, _)  => {
        Ok(())
      },
      &mut LoggerBackend::Tcp(ref mut socket)        => {
        socket.flush()
      }
    }
  }
}

/// Returns a Logger using unix socket to target local syslog ( using /dev/log or /var/run/syslog)
pub fn unix<U: Display, F: Clone+LogFormat<U>>(formatter: F) -> Result<Logger<LoggerBackend, U, F>> {
    unix_connect(formatter.clone(), "/dev/log").or_else(|e| {
      if let &ErrorKind::Io(ref io_err) = e.kind() {
        if io_err.kind() == io::ErrorKind::NotFound {
          return unix_connect(formatter, "/var/run/syslog");
        }
      }
      Err(e)
    }).chain_err(|| ErrorKind::Initialization)
}

/// Returns a Logger using unix socket to target local syslog at user provided path
pub fn unix_custom<P: AsRef<Path>, U: Display, F: LogFormat<U>>(formatter: F, path: P) -> Result<Logger<LoggerBackend, U, F>> {
  unix_connect(formatter, path).chain_err(|| ErrorKind::Initialization)
}

fn unix_connect<P: AsRef<Path>, U: Display, F: LogFormat<U>>(formatter: F, path: P) -> Result<Logger<LoggerBackend, U, F>> {
  let sock = UnixDatagram::unbound()?;
  match sock.connect(&path) {
    Ok(()) => {
        println!("ok");
        Ok(Logger {
          formatter: formatter,
          backend:   LoggerBackend::Unix(sock),
          phantom:   PhantomData,
        })
    },
    Err(ref e) if e.raw_os_error() == Some(libc::EPROTOTYPE) => {
        println!("testing stream");
        let sock = UnixStream::connect(path)?;
        Ok(Logger {
            formatter: formatter,
            backend:   LoggerBackend::UnixStream(BufWriter::new(sock)),
            phantom:   PhantomData,
        })
    },
    Err(e) => Err(e.into()),
  }
}

/// returns a UDP logger connecting `local` and `server`
pub fn udp<T: ToSocketAddrs, U: Display, F: LogFormat<U>>(formatter: F, local: T, server: T) -> Result<Logger<LoggerBackend, U, F>> {
  server.to_socket_addrs().chain_err(|| ErrorKind::Initialization).and_then(|mut server_addr_opt| {
    server_addr_opt.next().chain_err(|| ErrorKind::Initialization)
  }).and_then(|server_addr| {
    UdpSocket::bind(local).chain_err(|| ErrorKind::Initialization).and_then(|socket| {
      Ok(Logger {
        formatter: formatter,
        backend:   LoggerBackend::Udp(socket, server_addr),
        phantom:   PhantomData,
      })
    })
  })
}

/// returns a TCP logger connecting `local` and `server`
pub fn tcp<T: ToSocketAddrs, U: Display, F: LogFormat<U>>(formatter: F, server: T) -> Result<Logger<LoggerBackend, U, F>> {
  TcpStream::connect(server).chain_err(|| ErrorKind::Initialization).and_then(|socket| {
    Ok(Logger {
      formatter: formatter,
      backend:   LoggerBackend::Tcp(BufWriter::new(socket)),
      phantom:   PhantomData,
    })
  })
}

pub struct BasicLogger {
  logger: Arc<Mutex<Logger<LoggerBackend, String, Formatter3164>>>,
}

impl BasicLogger {
  pub fn new(logger: Logger<LoggerBackend, String, Formatter3164>) -> BasicLogger {
    BasicLogger {
      logger: Arc::new(Mutex::new(logger)),
    }
  }
}

#[allow(unused_variables,unused_must_use)]
impl Log for BasicLogger {
  fn enabled(&self, metadata: &Metadata) -> bool {
    true
  }

  fn log(&self, record: &Record) {
    //FIXME: temporary patch to compile
    let message = format!("{}", record.args());
    let mut logger = self.logger.lock().unwrap();
    match record.level() {
      Level::Error => logger.err(message),
      Level::Warn  => logger.warning(message),
      Level::Info  => logger.info(message),
      Level::Debug => logger.debug(message),
      Level::Trace => logger.debug(message)
    };
  }

  fn flush(&self) {
      let _ = self.logger.lock().unwrap().backend.flush();
  }
}

/// Unix socket Logger init function compatible with log crate
pub fn init_unix(facility: Facility, log_level: log::LevelFilter) -> Result<()> {
  let (process_name, pid) = get_process_info()?;
  let formatter = Formatter3164 {
    facility: facility.clone(),
    hostname: None,
    process:  process_name,
    pid:      pid,
  };
  unix(formatter).and_then(|logger| {
    log::set_boxed_logger(Box::new(BasicLogger::new(logger))
    ).chain_err(|| ErrorKind::Initialization)
  })?;

    log::set_max_level(log_level);
    Ok(())
}

/// Unix socket Logger init function compatible with log crate and user provided socket path
pub fn init_unix_custom<P: AsRef<Path>>(facility: Facility, log_level: log::LevelFilter, path: P) -> Result<()> {
  let (process_name, pid) = get_process_info()?;
  let formatter = Formatter3164 {
    facility: facility.clone(),
    hostname: None,
    process:  process_name,
    pid:      pid,
  };
  unix_custom(formatter, path).and_then(|logger| {
    log::set_boxed_logger(Box::new(BasicLogger::new(logger)))
    .chain_err(|| ErrorKind::Initialization)
  })?;

    log::set_max_level(log_level);
    Ok(())
}

/// UDP Logger init function compatible with log crate
pub fn init_udp<T: ToSocketAddrs>(local: T, server: T, hostname:String, facility: Facility, log_level: log::LevelFilter) -> Result<()> {
  let (process_name, pid) = get_process_info()?;
  let formatter = Formatter3164 {
    facility: facility.clone(),
    hostname: Some(hostname),
    process:  process_name,
    pid:      pid,
  };
  udp(formatter, local, server).and_then(|logger| {
    log::set_boxed_logger(Box::new(BasicLogger::new(logger))).chain_err(|| ErrorKind::Initialization)
  })?;

  log::set_max_level(log_level);
  Ok(())
}

/// TCP Logger init function compatible with log crate
pub fn init_tcp<T: ToSocketAddrs>(server: T, hostname: String, facility: Facility, log_level: log::LevelFilter) -> Result<()> {
  let (process_name, pid) = get_process_info()?;
  let formatter = Formatter3164 {
    facility: facility.clone(),
    hostname: Some(hostname),
    process:  process_name,
    pid:      pid,
  };

  tcp(formatter, server).and_then(|logger| {
    log::set_boxed_logger(Box::new(BasicLogger::new(logger))).chain_err(|| ErrorKind::Initialization)
  })?;

  log::set_max_level(log_level);
  Ok(())
}

/// Initializes logging subsystem for log crate
///
/// This tries to connect to syslog by following ways:
///
/// 1. Unix sockets /dev/log and /var/run/syslog (in this order)
/// 2. Tcp connection to 127.0.0.1:601
/// 3. Udp connection to 127.0.0.1:514
///
/// Note the last option usually (almost) never fails in this method. So
/// this method doesn't return error even if there is no syslog.
///
/// If `application_name` is `None` name is derived from executable name
pub fn init(facility: Facility, log_level: log::LevelFilter,
    application_name: Option<&str>)
    -> Result<()>
{
  let (process_name, pid) = get_process_info()?;
  let formatter = Formatter3164 {
    facility: facility.clone(),
    hostname: None,
    process:  application_name
      .map(|v| v.to_string())
      .unwrap_or(process_name),
    pid:      pid,
  };

  let backend = unix(formatter.clone()).map(|logger: Logger<LoggerBackend, String, Formatter3164>| logger.backend)
    .or_else(|_| {
        TcpStream::connect(("127.0.0.1", 601))
        .map(|s| LoggerBackend::Tcp(BufWriter::new(s)))
    })
    .or_else(|_| {
        let udp_addr = "127.0.0.1:514".parse().unwrap();
        UdpSocket::bind(("127.0.0.1", 0))
        .map(|s| LoggerBackend::Udp(s, udp_addr))
    })?;
  log::set_boxed_logger(    Box::new(BasicLogger::new(Logger {
      formatter: formatter,
      backend:   backend,
      phantom:   PhantomData,
    }))
  ).chain_err(|| ErrorKind::Initialization)?;

    log::set_max_level(log_level);
    Ok(())
}

fn get_process_info() -> Result<(String,i32)> {
  env::current_exe().chain_err(|| ErrorKind::Initialization).and_then(|path| {
    path.file_name().and_then(|os_name| os_name.to_str()).map(|name| name.to_string())
      .chain_err(|| ErrorKind::Initialization)
  }).map(|name| {
    let pid = unsafe { getpid() };
    (name, pid)
  })
}