daemonize2/
error.rs

1// SPDX-License-Identifier: MIT OR Apache-2.0
2//
3// This file is licensed under the MIT license or the Apache License, Version 2.0, at your choice.
4//
5// Copyright 2016 Fedor Gogolev
6// Copyright 2025 Oliver Old
7//
8// Licensed under the Apache License, Version 2.0 (the "License");
9// you may not use this file except in compliance with the License.
10// You may obtain a copy of the License at
11//
12//     http://www.apache.org/licenses/LICENSE-2.0
13//
14// Unless required by applicable law or agreed to in writing, software
15// distributed under the License is distributed on an "AS IS" BASIS,
16// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17// See the License for the specific language governing permissions and
18// limitations under the License.
19
20pub type Errno = libc::c_int;
21
22/// Error type returned by `Daemonize::start()`.
23#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
24pub struct Error(ErrorKind);
25
26impl Error {
27    pub fn kind(&self) -> ErrorKind {
28        self.0
29    }
30}
31
32/// Error kind used inside `struct Error`.
33#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
34pub enum ErrorKind {
35    Fork(Errno),
36    Wait(Errno),
37    DetachSession(Errno),
38    GroupNotFound,
39    GroupContainsNul,
40    SetGroup(Errno),
41    UserNotFound,
42    UserContainsNul,
43    SetUser(Errno),
44    ChangeDirectory(Errno),
45    PathContainsNul,
46    OpenPidfile(Errno),
47    GetPidfileFlags(Errno),
48    SetPidfileFlags(Errno),
49    LockPidfile(Errno),
50    ChownPidfile(Errno),
51    OpenDevnull(Errno),
52    RedirectStreams(Errno),
53    CloseDevnull(Errno),
54    TruncatePidfile(Errno),
55    WritePid(Errno),
56    WritePidUnspecifiedError,
57    Chroot(Errno),
58}
59
60impl ErrorKind {
61    fn description(&self) -> &str {
62        match self {
63            ErrorKind::Fork(_) => "unable to fork",
64            ErrorKind::Wait(_) => "wait failed",
65            ErrorKind::DetachSession(_) => "unable to create new session",
66            ErrorKind::GroupNotFound => "unable to resolve group name to group id",
67            ErrorKind::GroupContainsNul => "group option contains NUL",
68            ErrorKind::SetGroup(_) => "unable to set group",
69            ErrorKind::UserNotFound => "unable to resolve user name to user id",
70            ErrorKind::UserContainsNul => "user option contains NUL",
71            ErrorKind::SetUser(_) => "unable to set user",
72            ErrorKind::ChangeDirectory(_) => "unable to change directory",
73            ErrorKind::PathContainsNul => "pid_file option contains NUL",
74            ErrorKind::OpenPidfile(_) => "unable to open pid file",
75            ErrorKind::GetPidfileFlags(_) => "unable get pid file flags",
76            ErrorKind::SetPidfileFlags(_) => "unable set pid file flags",
77            ErrorKind::LockPidfile(_) => "unable to lock pid file",
78            ErrorKind::ChownPidfile(_) => "unable to chown pid file",
79            ErrorKind::OpenDevnull(_) => "unable to open /dev/null",
80            ErrorKind::RedirectStreams(_) => "unable to redirect standard streams to /dev/null",
81            ErrorKind::CloseDevnull(_) => "unable to close /dev/null",
82            ErrorKind::TruncatePidfile(_) => "unable to truncate pid file",
83            ErrorKind::WritePid(_) => "unable to write self pid to pid file",
84            ErrorKind::WritePidUnspecifiedError => {
85                "unable to write self pid to pid file due to unknown reason"
86            }
87            ErrorKind::Chroot(_) => "unable to chroot into directory",
88        }
89    }
90
91    fn errno(&self) -> Option<Errno> {
92        match self {
93            ErrorKind::Fork(errno) => Some(*errno),
94            ErrorKind::Wait(errno) => Some(*errno),
95            ErrorKind::DetachSession(errno) => Some(*errno),
96            ErrorKind::GroupNotFound => None,
97            ErrorKind::GroupContainsNul => None,
98            ErrorKind::SetGroup(errno) => Some(*errno),
99            ErrorKind::UserNotFound => None,
100            ErrorKind::UserContainsNul => None,
101            ErrorKind::SetUser(errno) => Some(*errno),
102            ErrorKind::ChangeDirectory(errno) => Some(*errno),
103            ErrorKind::PathContainsNul => None,
104            ErrorKind::OpenPidfile(errno) => Some(*errno),
105            ErrorKind::GetPidfileFlags(errno) => Some(*errno),
106            ErrorKind::SetPidfileFlags(errno) => Some(*errno),
107            ErrorKind::LockPidfile(errno) => Some(*errno),
108            ErrorKind::ChownPidfile(errno) => Some(*errno),
109            ErrorKind::OpenDevnull(errno) => Some(*errno),
110            ErrorKind::RedirectStreams(errno) => Some(*errno),
111            ErrorKind::CloseDevnull(errno) => Some(*errno),
112            ErrorKind::TruncatePidfile(errno) => Some(*errno),
113            ErrorKind::WritePid(errno) => Some(*errno),
114            ErrorKind::WritePidUnspecifiedError => None,
115            ErrorKind::Chroot(errno) => Some(*errno),
116        }
117    }
118}
119
120impl std::fmt::Display for ErrorKind {
121    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
122        f.write_str(self.description())?;
123        if let Some(errno) = self.errno() {
124            write!(f, ", errno {}", errno)?
125        }
126        Ok(())
127    }
128}
129
130impl std::error::Error for ErrorKind {}
131
132impl std::fmt::Display for Error {
133    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
134        write!(f, "{}", self.kind())
135    }
136}
137
138impl std::error::Error for Error {}
139
140impl From<ErrorKind> for Error {
141    fn from(kind: ErrorKind) -> Self {
142        Self(kind)
143    }
144}
145
146pub trait Num {
147    fn is_err(&self) -> bool;
148}
149
150impl Num for i8 {
151    fn is_err(&self) -> bool {
152        *self == -1
153    }
154}
155
156impl Num for i16 {
157    fn is_err(&self) -> bool {
158        *self == -1
159    }
160}
161
162impl Num for i32 {
163    fn is_err(&self) -> bool {
164        *self == -1
165    }
166}
167
168impl Num for i64 {
169    fn is_err(&self) -> bool {
170        *self == -1
171    }
172}
173
174impl Num for isize {
175    fn is_err(&self) -> bool {
176        *self == -1
177    }
178}
179
180pub fn check_err<N: Num, F: FnOnce(Errno) -> ErrorKind>(ret: N, f: F) -> Result<N, ErrorKind> {
181    if ret.is_err() {
182        Err(f(errno::errno().into()))
183    } else {
184        Ok(ret)
185    }
186}
daemonize2/error.rs

daemonize2/
error.rs
