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comparison src/logging.rs @ 92:5ddbcada30f2

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Add the ability to log against a PAM handle. PAM impls provide a way to log to syslog. This exposes it via nonstick.
author Paul Fisher <paul@pfish.zone>
date Sun, 22 Jun 2025 19:29:32 -0400
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children b87100c5eed4
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91:039aae9a01f7 92:5ddbcada30f2
1 //! PAM logging variables and macros.
2 //!
3 //! PAM implementations usually include the ability to log to syslog in a way
4 //! that is associated with the log entry itself. This module defines the enums
5 //! and macros for logging.
6 //!
7 //! For more details, see [`PamShared::log`](crate::PamShared::log).
8 //!
9 //! We can't use [the `log` crate](https://docs.rs/log) because that requires
10 //! that any `Log` implementors be `Sync` and `Send`, and a PAM handle
11 //! may be neither. Furthermore, PAM handles are passed to PAM modules in
12 //! dynamic libraries, and `log` doesn't work across dynamic linking boundaries.
13 //!
14 //! A `PamShared` implementation may still use the `log` crate on the backend,
15 //! and may even itself implement `log::Log`, but that interface is not exposed
16 //! to the generic PAM user.
17
18 #[cfg(feature = "link")]
19 mod levels {
20 pub use internal::*;
21 #[cfg(pam_impl = "linux-pam")]
22 mod internal {
23 use crate::libpam::pam_ffi;
24 pub const ERROR: u32 = pam_ffi::LOG_ERR;
25 pub const WARN: u32 = pam_ffi::LOG_WARNING;
26 pub const INFO: u32 = pam_ffi::LOG_INFO;
27 pub const DEBUG: u32 = pam_ffi::LOG_DEBUG;
28 }
29 #[cfg(pam_impl = "openpam")]
30 mod internal {
31 use crate::libpam::pam_ffi;
32 pub const ERROR: u32 = pam_ffi::PAM_LOG_ERROR;
33 pub const WARN: u32 = pam_ffi::PAM_LOG_NOTICE;
34 pub const INFO: u32 = pam_ffi::PAM_LOG_VERBOSE;
35 pub const DEBUG: u32 = pam_ffi::PAM_LOG_DEBUG;
36 }
37 }
38
39 #[cfg(not(feature = "link"))]
40 mod levels {
41 pub const ERROR: u32 = 2255887;
42 pub const WARN: u32 = 7265000;
43 pub const INFO: u32 = 7762323;
44 pub const DEBUG: u32 = 8675309;
45 }
46
47 /// An entry to be added to the log.
48 ///
49 /// The levels are in descending order of importance and correspond roughly
50 /// to the similarly-named levels in the `log` crate.
51 ///
52 /// In all implementations, these are ordered such that `Error`, `Warning`,
53 /// `Info`, and `Debug` are in ascending order.
54 #[derive(Debug, PartialEq, Ord, PartialOrd, Eq)]
55 #[repr(u32)]
56 pub enum Level {
57 Error = levels::ERROR,
58 Warning = levels::WARN,
59 Info = levels::INFO,
60 Debug = levels::DEBUG,
61 }
62
63 /// Here's the guts of the logger thingy. You shouldn't be using this!
64 #[doc(hidden)]
65 #[macro_export]
66 macro_rules! __log_internal {
67 ($handle:expr, $level:ident, $($arg:tt)+) => {
68 $handle.log($crate::logging::Level::$level, &format!($($arg)+));
69 }
70 }
71
72 /// Logs a message at error level via the given PAM handle.
73 ///
74 /// This supports `format!`-style formatting.
75 ///
76 /// # Example
77 ///
78 /// ```no_run
79 /// # let pam_handle: Box<dyn nonstick::PamShared> = unimplemented!();
80 /// # let load_error = "xxx";
81 /// nonstick::error!(pam_handle, "error loading data from data source: {load_error}");
82 /// // Will log a message like "error loading data from data source: timed out"
83 /// // at ERROR level on syslog.
84 /// ```
85 #[macro_export]
86 macro_rules! error { ($handle:expr, $($arg:tt)+) => { $crate::__log_internal!($handle, Error, $($arg)+);}}
87
88 /// Logs a message at warning level via the given PAM handle.
89 ///
90 /// This supports `format!`-style formatting.
91 ///
92 /// # Example
93 ///
94 /// ```no_run
95 /// # let pam_handle: Box<dyn nonstick::PamShared> = unimplemented!();
96 /// # let latency_ms = "xxx";
97 /// nonstick::warn!(pam_handle, "loading took too long: {latency_ms} ms");
98 /// // Will log a message like "loading took too long: 495 ms"
99 /// // at WARN level on syslog.
100 /// ```
101 #[macro_export]
102 macro_rules! warn { ($handle:expr, $($arg:tt)+) => { $crate::__log_internal!($handle, Warning, $($arg)+);}}
103
104 /// Logs a message at info level via the given PAM handle.
105 ///
106 /// This supports `format!`-style formatting.
107 ///
108 /// # Example
109 ///
110 /// ```no_run
111 /// # let pam_handle: Box<dyn nonstick::PamShared> = unimplemented!();
112 /// nonstick::info!(pam_handle, "using remote backend to load user data");
113 /// // Will log a message like "using remote backend to load user data"
114 /// // at INFO level on syslog.
115 /// ```
116 #[macro_export]
117 macro_rules! info { ($handle:expr, $($arg:tt)+) => { $crate::__log_internal!($handle, Info, $($arg)+);}}
118
119 /// Logs a message at debug level via the given PAM handle.
120 ///
121 /// This level specially includes file/line/column information.
122 /// This supports `format!`-style formatting.
123 ///
124 /// # Example
125 ///
126 /// ```no_run
127 /// # let pam_handle: Box<dyn nonstick::PamShared> = unimplemented!();
128 /// # let userinfo_url = "https://zombo.com/";
129 /// nonstick::debug!(pam_handle, "making HTTP GET request to {userinfo_url}");
130 /// // Will log a message like
131 /// // "pam_http/lib.rs:39:14: making HTTP GET request to https://zombo.com/"
132 /// // at DEBUG level on syslog.
133 /// ```
134 #[macro_export]
135 macro_rules! debug {($handle:expr, $($arg:tt)+) => {
136 $crate::__log_internal!(
137 $handle, Debug,
138 "{}:{}:{}: {}", file!(), line!(), column!(), format_args!($($arg)+),
139 );
140 }}
141
142 #[cfg(test)]
143 mod tests {
144 use super::*;
145 use regex::Regex;
146 use std::cell::RefCell;
147
148 #[test]
149 fn test_order() {
150 assert!(Level::Error < Level::Warning);
151 assert!(Level::Warning < Level::Info);
152 assert!(Level::Info < Level::Debug);
153 }
154
155 #[test]
156 fn test_logging() {
157 struct Logger(RefCell<Vec<(Level, String)>>);
158
159 impl Logger {
160 fn log(&self, level: Level, text: &str) {
161 self.0.borrow_mut().push((level, text.to_owned()))
162 }
163 }
164
165 let logger = Logger(Default::default());
166
167 let something = Level::Error;
168 error!(logger, "here is another thing: {}", 99);
169 warn!(logger, "watch out!");
170 info!(logger, "here is some info: {info}", info = "information");
171 debug!(logger, "here is something: {something:?}");
172
173 let mut logged = logger.0.into_inner();
174
175 let (last_level, last_string) = logged.pop().unwrap();
176 assert_eq!(Level::Debug, last_level);
177 let expr = Regex::new(r"^[^:]+:\d+:\d+: here is something: Error$").unwrap();
178 assert!(
179 expr.is_match(&last_string),
180 "{last_string:?} did not match {expr:?}"
181 );
182
183 assert_eq!(
184 vec![
185 (Level::Error, "here is another thing: 99".to_owned()),
186 (Level::Warning, "watch out!".to_owned()),
187 (Level::Info, "here is some info: information".to_owned()),
188 ],
189 logged
190 );
191 }
192 }